Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

DOE PAGES

Carlton, Holly D.; Elmer, John W.; Li, Yan; ...

2016-04-13

For this study synchrotron radiation micro-­tomography, a non-destructive three-dimensional imaging technique, is employed to investigate an entire microelectronic package with a cross-sectional area of 16 x 16 mm. Due to the synchrotron’s high flux and brightness the sample was imaged in just 3 minutes with an 8.7 μm spatial resolution.

Self-Patterning of Silica/Epoxy Nanocomposite Underfill by Tailored Hydrophilic-Superhydrophobic Surfaces for 3D Integrated Circuit (IC) Stacking.

PubMed

Tuan, Chia-Chi; James, Nathan Pataki; Lin, Ziyin; Chen, Yun; Liu, Yan; Moon, Kyoung-Sik; Li, Zhuo; Wong, C P

2017-03-15

As microelectronics are trending toward smaller packages and integrated circuit (IC) stacks nowadays, underfill, the polymer composite filled in between the IC chip and the substrate, becomes increasingly important for interconnection reliability. However, traditional underfills cannot meet the requirements for low-profile and fine pitch in high density IC stacking packages. Post-applied underfills have difficulties in flowing into the small gaps between the chip and the substrate, while pre-applied underfills face filler entrapment at bond pads. In this report, we present a self-patterning underfilling technology that uses selective wetting of underfill on Cu bond pads and Si 3 N 4 passivation via surface energy engineering. This novel process, fully compatible with the conventional underfilling process, eliminates the issue of filler entrapment in typical pre-applied underfilling process, enabling high density and fine pitch IC die bonding.

Government Microelectronics Assessment for Trust (GOMAT)

NASA Technical Reports Server (NTRS)

Berg, Melanie D.; LaBel, Kenneth A.

2018-01-01

NASA Electronic Parts and Packaging (NEPP) is developing a process to be employed in critical applications. The framework assesses levels of trust and assurance in microelectronic systems. The process is being created with participation from a variety of organizations. We present a synopsis of the framework that includes contributions from The Aerospace Corporation.

Synthesis of tin, silver and their alloy nanoparticles for lead-free interconnect applications

NASA Astrophysics Data System (ADS)

Jiang, Hongjin

SnPb solders have long been used as interconnect materials in microelectronic packaging. Due to the health threat of lead to human beings, the use of lead-free interconnect materials is imperative. Three kinds of lead-free interconnect materials are being investigated, namely lead-free metal solders (SnAg, SnAgCu, etc.), electrically conductive adhesives (ECAs) and carbon nanotubes (CNTs). However, there are still limitations for the full utilization of these lead-free interconnect materials in the microelectronic packaging, such as higher melting point of lead-free metal solders, lower electrical conductivity of the ECAs and poor adhesion of CNTs to substrates. This thesis is devoted to the research and development of low processing temperature lead-free interconnect materials for microelectronic packaging applications with an emphasis on fundamental studies of nanoparticles synthesis, dispersion and oxidation prevention, and nanocomposites fabrication. Oxide-free tin (Sn), tin/silver (96.5Sn3.5Ag) and tin/silver/copper (96.5Sn3.0Ag0.5Cu) alloy nanoparticles with different sizes were synthesized by a low temperature chemical reduction method. Both size dependent melting point and latent heat of fusion of the synthesized nanoparticles were obtained. The nano lead-free solder pastes/composites created by dispersing the SnAg or SnAgCu alloy nanoparticles into an acidic type flux spread and wet on the cleaned copper surface at 220 to 230°C. This study demonstrated the feasibility of nano sized SnAg or SnAgCu alloy particle pastes for low processing temperature lead-free interconnect applications in microelectronic packaging.

FOREWORD: Proceedings of the 39th International Microelectronics and Packaging IMAPS Poland Conference

NASA Astrophysics Data System (ADS)

Jasiński, Piotr; Górecki, Krzysztof; Bogdanowicz, Robert

2016-01-01

These proceedings are a collection of the selected articles presented at the 39th International Microelectronics and Packaging IMAPS Poland Conference, held in Gdansk, Poland on September 20-23, 2015 (IMAPS Poland 2015). The conference has been held under the scientific patronage of the International Microelectronics and Packaging Society Poland Chapter and the Committee of Electronics and Telecommunication, Polish Academy of Science and jointly hosted by the Gdansk University of Technology, Faculty of Electronics, Telecommunication and Informatics (GUT) and the Gdynia Maritime University, Faculty of Electrical Engineering (GMU). The IMAPS Poland conference series aims to advance interdisciplinary scientific information exchange and the discussion of the science and technology of advanced electronics. The IMAPS Poland 2015 conference took place in the heart of Gdansk, two minutes walking distance from the beach. The surroundings and location of the venue guaranteed excellent working and leisure conditions. The three-day conference highlighted invited talks by outstanding scientists working in important areas of electronics and electronic material science. The eight sessions covered areas in the fields of electronics packaging, interconnects on PCB, Low Temperature Co-fired Ceramic (LTCC), MEMS devices, transducers, sensors and modelling of electronic devices. The conference was attended by 99 participants from 11 countries. The conference schedule included 18 invited presentations and 78 poster presentations.

Risk Management of Microelectronics: The NASA Electronic Parts and Packaging (NEPP) Program

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Sampson, Michael J.

2005-01-01

This viewgraph information provides information on how the NASA Electronic Parts and Packaging (NEPP) Program evaluates the reliability of technologies for Electrical, Electronic, and Electromechanical (EEE) parts, and their suitability for spacecraft applications.

Configurations of high-frequency ultrasonics complex vibration systems for packaging in microelectronics.

PubMed

Tsujino, Jiromaru; Harada, Yoshiki; Ihara, Shigeru; Kasahara, Kohei; Shimizu, Masanori; Ueoka, Tetsugi

2004-04-01

Ultrasonic high-frequency complex vibrations are effective for various ultrasonic high-power applications. Three types of ultrasonic complex vibration system with a welding tip vibrating elliptical to circular locus for packaging in microelectronics were studied. The complex vibration sources are using (1) a longitudinal-torsional vibration converter with diagonal slits that is driven only by a longitudinal vibration source, (2) a complex transverse vibration rod with several stepped parts that is driven by two longitudinal vibration source crossed at a right angle and (3) a longitudinal vibration circular disk and three longitudinal transducers that are installed at the circumference of the disk.

Electric Field Control of Magnetism Using BiFeO3-Based Heterostructures

DTIC Science & Technology

2014-04-22

dissipation in the form of heat has become a center stage issue for the microelectronics industry. By taking advantage of the strong correlations...speed and storage density, significant energy dissipation in the form of heat has become a center stage issue for the microelectronics industry. By...and storage density, significant energy dissipation in the form of heat has become a center stage issue for the microelectronics industry. By taking

IEEE WMED 2016 Homepage

Science.gov Websites

characterization, design, and new device technologies. This workshop will consist of invited talks, contributed and Reliability Semiconductor package reliability, Design for Manufacturability, Stacked die packaging and Novel assembly processes Microelectronic Circuit Design New product design, high-speed and/or low

Thermal shock testing for assuring reliability of glass-sealed microelectronic packages

NASA Technical Reports Server (NTRS)

Thomas, Walter B., III; Lewis, Michael D.

1991-01-01

Tests were performed to determine if thermal shocking is destructive to glass-to-metal seal microelectronic packages and if thermal shock step stressing can compare package reliabilities. Thermal shocking was shown to be not destructive to highly reliable glass seals. Pin-pull tests used to compare the interfacial pin glass strengths showed no differences between thermal shocked and not-thermal shocked headers. A 'critical stress resistance temperature' was not exhibited by the 14 pin Dual In-line Package (DIP) headers evaluated. Headers manufactured in cryogenic nitrogen based and exothermically generated atmospheres showed differences in as-received leak rates, residual oxide depths and pin glass interfacial strengths; these were caused by the different manufacturing methods, in particular, by the chemically etched pins used by one manufacturer. Both header types passed thermal shock tests to temperature differentials of 646 C. The sensitivity of helium leak rate measurements was improved up to 70 percent by baking headers for two hours at 200 C after thermal shocking.

Vacuum microelectronics for beam power and rectennas

NASA Technical Reports Server (NTRS)

Gray, Henry F.

1989-01-01

Vacuum Microelectronic devices can be described as vacuum transistors or micro-miniature vacuum tubes, as one chooses. The fundamental reason behind this new technology is the very large current densities available from field emitters, namely as high as 10(8) A/sq cm. Array current densities as high as 1000 A/sq cm have been measured. Total electron transit times from source to drain for 1 micron feature size devices have been predicted to be about 150fs. This very short transit time implies the possibility of submillimeter wave transmitters and rectennas in devices which can operate with reasonably high voltages and which are small in size and are lightweight. In addition, they are expected to be extremely radiation hard and very temperature insensitive. That is, they are expected to have radiation hardness characteristics similar to vacuum tubes, and both the high temperature and low temperature limits should be determined by the package. That is, there should be no practical intrinsic temperature or carrier freezeout problems for devices based on metals or composites. But the technology is difficult to implement at the present time because it is based on 300 to 500 angstrom radius field emitters which must be relatively uniform. There is also the need to understand the non-equilibrium transport physics in the near-surface regions of the field emitters.

Wetting properties of Au/Sn solders for microelectronics

NASA Astrophysics Data System (ADS)

Peterson, K. A.; Williams, C. B.

Hermetic sealing of microelectronic packages with Au/Sn solder is critically dependent upon good wetting. In studying specific problems in hermetic sealing, a solderability test based on ASTM standard F-357-78 has proven useful. The test has helped isolate and quantify the effects of contamination due to epoxy die attach and related handling, thermal preconditioning of packages, gold plating thickness, time and temperature during sealing, and solder alloy composition as they affect wetting. Some differences in hardware have been documented between manufacturing lots, but the overriding factors have been contamination which occurs during packaging process flows and thermal preconditioning during processing. The paper includes a review of metallurgical aspects of soldering to a non-inert surface and an examination of microstructural differences in seal joints. The results also quantify the conventional wisdom that alloys which are on the tin-rich side of the eutectic composition offer superior wetting properties.

Laser-machined piezoelectric cantilevers for mechanical energy harvesting.

PubMed

Kim, HyunUk; Bedekar, Vishwas; Islam, Rashed Adnan; Lee, Woo-Ho; Leo, Don; Priya, Shashank

2008-09-01

In this study, we report results on a piezoelectric- material-based mechanical energy-harvesting device that was fabricated by combining laser machining with microelectronics packaging technology. It was found that the laser-machining process did not have significant effect on the electrical properties of piezoelectric material. The fabricated device was tested in the low-frequency regime of 50 to 1000 Hz at constant force of 8 g (where g = 9.8 m/s(2)). The device was found to generate continuous power of 1.13 microW at 870 Hz across a 288.5 kOmega load with a power density of 301.3 microW/cm(3).

CRRES microelectronics package flight data analysis

NASA Technical Reports Server (NTRS)

Stassinopoulos, E. G.; Brucker, G. J.; Stauffer, C. A.

1993-01-01

A detailed in-depth analysis was performed on the data from some of the CRRES MEP (Microelectronics Package) devices. These space flight measurements covered a period of about fourteen months of mission lifetime. Several types of invalid data were identified and corrections were made. Other problems were noted and adjustments applied, as necessary. Particularly important and surprising were observations of abnormal device behavior in many parts that could neither be explained nor correlated to causative events. Also, contrary to prevailing theory, proton effects appeared to be far more significant and numerous than cosmic ray effects. Another unexpected result was the realization that only nine out of thirty-two p-MOS dosimeters on the MEP indicated a valid operation. Comments, conclusions, and recommendations are given.

Microcomputer Materials from MEP. An Annotated Directory of Packages of Interest to Further Education. An Occasional Paper.

ERIC Educational Resources Information Center

Gilbert, Leslie

Designed to disseminate information to the post-school sector of United Kingdom education, this directory provides information on 50 microcomputer software packages developed by the Microelectronics Education Program (MEP) and available through educational publishers. Subject areas represented include accountancy, biology, business education,…

Rugged microelectronic module package supports circuitry on heat sink

NASA Technical Reports Server (NTRS)

Johnson, A. L.

1966-01-01

Rugged module package for thin film hybrid microcircuits incorporated a rigid, thermally conductive support structure, which serves as a heat sink, and a lead wire block in which T-shaped electrical connectors are potted. It protects the circuitry from shock and vibration loads, dissipates internal heat, and simplifies electrical connections between adjacent modules.

Thick, low-stress films, and coated substrates formed therefrom

DOEpatents

Henager, Jr., Charles H.; Knoll, Robert W.

1991-01-01

Stress-induced deformation, and the damage resulting therefrom, increases with film thickness. The overcoming of excessive stress by the use of the film material of the present invention, permits the formation of thick films that are necessary for certain of the above described applications. The most likely use for the subject film materials, other than their specialized views as an optical film, is for microelectronic packaging of components on silicon substrates. In general, the subject Si-Al-O-N films have excellent adherence to the underlying substrate, a high degree of hardness and durability, and are excellent insulators. Prior art elevated temperature deposition processes cannot meet the microelectronic packaging temperature formation constraints. The process of the present invention is conducted under non-elevated temperature conditions, typically 500# C. or less.

Microstructure-Evolution and Reliability Assessment Tool for Lead-Free Component Insertion in Army Electronics

DTIC Science & Technology

2008-10-01

provide adequate means for thermal heat dissipation and cooling. Thus electronic packaging has four main functions [1]: • Signal distribution which... dissipation , involving structural and materials consideration. • Mechanical, chemical and electromagnetic protection of components and... nature when compared to phenomenological models. Microelectronic packaging industry spends typically several months building and reliability

Thick, low-stress films, and coated substrates formed therefrom, and methods for making same

DOEpatents

Henager, Jr., Charles H.; Knoll, Robert W.

1992-01-01

Stress-induced deformation, and the damage resulting therefrom, increases with film thickness. The overcoming of excessive stress by the use of the Si-Al-N film material of the present invention, permits the formation of thick films that are necessary for certain of the above described applications. The most likely use for the subject film materials, other than their specialized views as an optical film, is for microelectronic packaging of components on silicon substrates. In general, the subject films have excellent adherence to the underlying substrate, a high degree of hardness and durability, and are excellent insulators. Prior art elevated temperature deposition processes cannot meet the microelectronic packaging temperature formation constraints. The process of the present invention is conducted under non-elevated temperature conditions, typically 500.degree. C. or less.

Moore's law and the impact on trusted and radiation-hardened microelectronics.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Kwok Kee

2011-12-01

In 1965 Gordon Moore wrote an article claiming that integrated circuit density would scale exponentially. His prediction has remained valid for more than four decades. Integrated circuits have changed all aspects of everyday life. They are also the 'heart and soul' of modern systems for defense, national infrastructure, and intelligence applications. The United States government needs an assured and trusted microelectronics supply for military systems. However, migration of microelectronics design and manufacturing from the United States to other countries in recent years has placed the supply of trusted microelectronics in jeopardy. Prevailing wisdom dictates that it is necessary to usemore » microelectronics fabricated in a state-of-the-art technology for highest performance and military system superiority. Close examination of silicon microelectronics technology evolution and Moore's Law reveals that this prevailing wisdom is not necessarily true. This presents the US government the possibility of a totally new approach to acquire trusted microelectronics.« less

Detection of micro solder balls using active thermography and probabilistic neural network

NASA Astrophysics Data System (ADS)

He, Zhenzhi; Wei, Li; Shao, Minghui; Lu, Xingning

2017-03-01

Micro solder ball/bump has been widely used in electronic packaging. It has been challenging to inspect these structures as the solder balls/bumps are often embedded between the component and substrates, especially in flip-chip packaging. In this paper, a detection method for micro solder ball/bump based on the active thermography and the probabilistic neural network is investigated. A VH680 infrared imager is used to capture the thermal image of the test vehicle, SFA10 packages. The temperature curves are processed using moving average technique to remove the peak noise. And the principal component analysis (PCA) is adopted to reconstruct the thermal images. The missed solder balls can be recognized explicitly in the second principal component image. Probabilistic neural network (PNN) is then established to identify the defective bump intelligently. The hot spots corresponding to the solder balls are segmented from the PCA reconstructed image, and statistic parameters are calculated. To characterize the thermal properties of solder bump quantitatively, three representative features are selected and used as the input vector in PNN clustering. The results show that the actual outputs and the expected outputs are consistent in identification of the missed solder balls, and all the bumps were recognized accurately, which demonstrates the viability of the PNN in effective defect inspection in high-density microelectronic packaging.

Two autowire versions for CDC-3200 and IBM-360

NASA Technical Reports Server (NTRS)

Billingsley, J. B.

1972-01-01

Microelectronics program was initiated to evaluate circuitry, packaging methods, and fabrication approaches necessary to produce completely procured logic system. Two autowire programs were developed for CDC-3200 and IBM-360 computers for use in designing logic systems.

Advanced packaging for Integrated Micro-Instruments

NASA Technical Reports Server (NTRS)

Lyke, James L.

1995-01-01

The relationship between packaging, microelectronics, and micro-electrical-mechanical systems (MEMS) is an important one, particularly when the edges of performance boundaries are pressed, as in the case of miniaturized systems. Packaging is a sort of physical backbone that enables the maximum performance of these systems to be realized, and the penalties imposed by conventional packing approaches is particularly limiting for MEMS devices. As such, advanced packaging approaches, such as multi-chip modules (MCM's) have been touted as a true means of electronic 'enablement' for a variety of application domains. Realizing an optimum system of packaging, however, in not as simple as replacing a set of single chip packages with a substrate of interconnections. Research at Phillips Laboratory has turned up a number of integrating options in the two- and three-dimensional rending of miniature systems with physical interconnection structures with intrinsically high performance. Not only do these structures motivate the redesign of integrated circuits (IC's) for lower power, but they possess interesting features that provide a framework for the direct integration of MEMS devices. Cost remains a barrier to the application of MEMS devices, even in space systems. Several innovations are suggested that will result in lower cost and more rapid cycle time. First, the novelty of a 'constant floor plan' MCM which encapsulates a variety of commonly used components into a stockable, easily customized assembly is discussed. Next, the use of low-cost substrates is examined. The anticipated advent of ultra-high density interconnect (UHDI) is suggested as the limit argument of advanced packaging. Finally, the concept of a heterogeneous 3-D MCM system is outlined that allows for the combination of different compatible packaging approaches into a uniformly dense structure that could also include MEMS-based sensors.

PICSiP: new system-in-package technology using a high bandwidth photonic interconnection layer for converged microsystems

NASA Astrophysics Data System (ADS)

Tekin, Tolga; Töpper, Michael; Reichl, Herbert

2009-05-01

Technological frontiers between semiconductor technology, packaging, and system design are disappearing. Scaling down geometries [1] alone does not provide improvement of performance, less power, smaller size, and lower cost. It will require "More than Moore" [2] through the tighter integration of system level components at the package level. System-in-Package (SiP) will deliver the efficient use of three dimensions (3D) through innovation in packaging and interconnect technology. A key bottleneck to the implementation of high-performance microelectronic systems, including SiP, is the lack of lowlatency, high-bandwidth, and high density off-chip interconnects. Some of the challenges in achieving high-bandwidth chip-to-chip communication using electrical interconnects include the high losses in the substrate dielectric, reflections and impedance discontinuities, and susceptibility to crosstalk [3]. Obviously, the incentive for the use of photonics to overcome the challenges and leverage low-latency and highbandwidth communication will enable the vision of optical computing within next generation architectures. Supercomputers of today offer sustained performance of more than petaflops, which can be increased by utilizing optical interconnects. Next generation computing architectures are needed with ultra low power consumption; ultra high performance with novel interconnection technologies. In this paper we will discuss a CMOS compatible underlying technology to enable next generation optical computing architectures. By introducing a new optical layer within the 3D SiP, the development of converged microsystems, deployment for next generation optical computing architecture will be leveraged.

Thermal Cycling Life Prediction of Sn-3.0Ag-0.5Cu Solder Joint Using Type-I Censored Data

PubMed Central

Mi, Jinhua; Yang, Yuan-Jian; Huang, Hong-Zhong

2014-01-01

Because solder joint interconnections are the weaknesses of microelectronic packaging, their reliability has great influence on the reliability of the entire packaging structure. Based on an accelerated life test the reliability assessment and life prediction of lead-free solder joints using Weibull distribution are investigated. The type-I interval censored lifetime data were collected from a thermal cycling test, which was implemented on microelectronic packaging with lead-free ball grid array (BGA) and fine-pitch ball grid array (FBGA) interconnection structures. The number of cycles to failure of lead-free solder joints is predicted by using a modified Engelmaier fatigue life model and a type-I censored data processing method. Then, the Pan model is employed to calculate the acceleration factor of this test. A comparison of life predictions between the proposed method and the ones calculated directly by Matlab and Minitab is conducted to demonstrate the practicability and effectiveness of the proposed method. At last, failure analysis and microstructure evolution of lead-free solders are carried out to provide useful guidance for the regular maintenance, replacement of substructure, and subsequent processing of electronic products. PMID:25121138

Thermal Conductivity of Carbon Nanotube Composite Films

NASA Technical Reports Server (NTRS)

Ngo, Quoc; Cruden, Brett A.; Cassell, Alan M.; Walker, Megan D.; Koehne, Jessica E.; Meyyappan, M.; Li, Jun; Yang, Cary Y.

2004-01-01

State-of-the-art ICs for microprocessors routinely dissipate power densities on the order of 50 W/sq cm. This large power is due to the localized heating of ICs operating at high frequencies, and must be managed for future high-frequency microelectronic applications. Our approach involves finding new and efficient thermally conductive materials. Exploiting carbon nanotube (CNT) films and composites for their superior axial thermal conductance properties has the potential for such an application requiring efficient heat transfer. In this work, we present thermal contact resistance measurement results for CNT and CNT-Cu composite films. It is shown that Cu-filled CNT arrays enhance thermal conductance when compared to as-grown CNT arrays. Furthermore, the CNT-Cu composite material provides a mechanically robust alternative to current IC packaging technology.

Laser-induced forward transfer for flip-chip packaging of single dies.

PubMed

Kaur, Kamal S; Van Steenberge, Geert

2015-03-20

Flip-chip (FC) packaging is a key technology for realizing high performance, ultra-miniaturized and high-density circuits in the micro-electronics industry. In this technique the chip and/or the substrate is bumped and the two are bonded via these conductive bumps. Many bumping techniques have been developed and intensively investigated since the introduction of the FC technology in 1960(1) such as stencil printing, stud bumping, evaporation and electroless/electroplating2. Despite the progress that these methods have made they all suffer from one or more than one drawbacks that need to be addressed such as cost, complex processing steps, high processing temperatures, manufacturing time and most importantly the lack of flexibility. In this paper, we demonstrate a simple and cost-effective laser-based bump forming technique known as Laser-induced Forward Transfer (LIFT)3. Using the LIFT technique a wide range of bump materials can be printed in a single-step with great flexibility, high speed and accuracy at RT. In addition, LIFT enables the bumping and bonding down to chip-scale, which is critical for fabricating ultra-miniature circuitry.

Development of a hybrid microelectronics solid state relay for 2500 volts isolation and minus 120 C to 80 C thermal cycling range

NASA Technical Reports Server (NTRS)

Sater, B. L.; Riley, T. J.; Janssen, W.

1973-01-01

A hybrid microelectronics solid state relay was developed in a TO-116 package for the MINX project. The relay provides 2500 Vdc input to output isolation and operated from a MHTL logic signal to switch a load of 400 Vdc at 2 mA. The relay is designed to operate in space and survive 1000 thermal cycles of 120 C to 80 C. The use of X-rays for failure analysis in small hybrid circuits proved valuable and the applications of vacuum deposited Parylene as a dielectric coating proved extremely valuable.

Reliability and quality EEE parts issues

NASA Technical Reports Server (NTRS)

Barney, Dan; Feigenbaum, Irwin

1990-01-01

NASA policy and procedures are established which govern the selection, testing, and application of electrical, electronic, and electromechanical (EEE) parts. Recent advances in the state-of-the-art of electronic parts and associated technologies can significantly impact the electronic designs and reliability of NASA space transportation avionics. Significant issues that result from these advances are examined, including: recent advances in microelectronics technology (as applied to or considered for use in NASA projects); electron packaging technology advances (concurrent with, and as a result of, the development of the advanced microelectronic devices); availability of parts used in space avionics; and standardization and integration of parts activities between projects, centers, and contractors.

NASA Electronic Parts and Packaging (NEPP) Program - Radiation Activities

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Sampson, Michael J.

2008-01-01

The NEPP mission is to provide guidance to NASA for the selection and application of microelectronics technologies, to improve understanding of the risks related to the use of these technologies in the space environment and to ensure that appropriate research is performed to meet NASA mission assurance needs.

ASIC/FPGA Trust Assessment Framework

NASA Technical Reports Server (NTRS)

Berg, Melanie

2018-01-01

NASA Electronic Parts and Packaging (NEPP) is developing a process to be employed in critical applications. The framework assesses levels of Trust and assurance in microelectronic systems. The process is being created with participation from a variety of organizations. We present a synopsis of the framework that includes contributions from The Aerospace Corporation.

Ultrasound aided smooth dispensing for high viscoelastic epoxy in microelectronic packaging.

PubMed

Chen, Yun; Li, Han-Xiong; Shan, Xiuyang; Gao, Jian; Chen, Xin; Wang, Fuliang

2016-01-01

Epoxy dispensing is one of the most critical processes in microelectronic packaging. However, due its high viscoelasticity, dispensing of epoxy is extremely difficult, and a lower viscoelasticity epoxy is desired to improve the process. In this paper, a novel method is proposed to achieve a lowered viscoelastic epoxy by using ultrasound. The viscoelasticity and molecular structures of the epoxies were compared and analyzed before and after experimentation. Different factors of the ultrasonic process, including power, processing time and ultrasonic energy, were studied in this study. It is found that elasticity is more sensitive to ultrasonic processing while viscosity is little affected. Further, large power and long processing time can minimize the viscoelasticity to ideal values. Due to the reduced loss modulus and storage modulus after ultrasonic processing, smooth dispensing is demonstrated for the processed epoxy. The subsequently color temperature experiments show that ultrasonic processing will not affect LED's lighting. It is clear that the ultrasonic processing will have good potential to aide smooth dispensing for high viscoelastic epoxy in electronic industry. Copyright © 2015 Elsevier B.V. All rights reserved.

Japan's technology and manufacturing infrastructure

NASA Astrophysics Data System (ADS)

Boulton, William R.; Meieran, Eugene S.; Tummala, Rao R.

1995-02-01

The JTEC panel found that, after four decades of development in electronics and manufacturing technologies, Japanese electronics companies are leaders in the development, support, and management of complex, low-cost packaging and assembly technologies used in the production of a broad range of consumer electronics products. The electronics industry's suppliers provide basic materials and equipment required for electronic packaging applications. Panelists concluded that some Japanese firms could be leading U.S. competitors by as much as a decade in these areas. Japan's technology and manufacturing infrastructure is an integral part of its microelectronics industry's success.

Japan's technology and manufacturing infrastructure

NASA Technical Reports Server (NTRS)

Boulton, William R.; Meieran, Eugene S.; Tummala, Rao R.

1995-01-01

The JTEC panel found that, after four decades of development in electronics and manufacturing technologies, Japanese electronics companies are leaders in the development, support, and management of complex, low-cost packaging and assembly technologies used in the production of a broad range of consumer electronics products. The electronics industry's suppliers provide basic materials and equipment required for electronic packaging applications. Panelists concluded that some Japanese firms could be leading U.S. competitors by as much as a decade in these areas. Japan's technology and manufacturing infrastructure is an integral part of its microelectronics industry's success.

NASA's 3D Flight Computer for Space Applications

NASA Technical Reports Server (NTRS)

Alkalai, Leon

2000-01-01

The New Millennium Program (NMP) Integrated Product Development Team (IPDT) for Microelectronics Systems was planning to validate a newly developed 3D Flight Computer system on its first deep-space flight, DS1, launched in October 1998. This computer, developed in the 1995-97 time frame, contains many new computer technologies previously never used in deep-space systems. They include: advanced 3D packaging architecture for future low-mass and low-volume avionics systems; high-density 3D packaged chip-stacks for both volatile and non-volatile mass memory: 400 Mbytes of local DRAM memory, and 128 Mbytes of Flash memory; high-bandwidth Peripheral Component Interface (Per) local-bus with a bridge to VME; high-bandwidth (20 Mbps) fiber-optic serial bus; and other attributes, such as standard support for Design for Testability (DFT). Even though this computer system did not complete on time for delivery to the DS1 project, it was an important development along a technology roadmap towards highly integrated and highly miniaturized avionics systems for deep-space applications. This continued technology development is now being performed by NASA's Deep Space System Development Program (also known as X2000) and within JPL's Center for Integrated Space Microsystems (CISM).

The NASA Electronic Parts and Packaging (NEPP) Program: An Overview

NASA Technical Reports Server (NTRS)

Label, Kenneth A.; Sampson, Michael J.

2016-01-01

This presentation provides an overview of the NEPP Program. The NEPP Mission is to provide guidance to NASA for the selection and application of microelectronics technologies; Improve understanding of the risks related to the use of these technologies in the space environment; Ensure that appropriate research is performed to meet NASA mission assurance needs. NEPP's Goals are to provide customers with appropriate and cost-effective risk knowledge to aid in: Selection and application of microelectronics technologies; Improved understanding of risks related to the use of these technologies in the space environment; Appropriate evaluations to meet NASA mission assurance needs; Guidelines for test and application of parts technologies in space; Assurance infrastructure and support for technologies in use by NASA space systems.

Gold-based electrical interconnections for microelectronic devices

DOEpatents

Peterson, Kenneth A.; Garrett, Stephen E.; Reber, Cathleen A.; Watson, Robert D.

2002-01-01

A method of making an electrical interconnection from a microelectronic device to a package, comprising ball or wedge compression bonding a gold-based conductor directly to a silicon surface, such as a polysilicon bonding pad in a MEMS or IMEMS device, without using layers of aluminum or titanium disposed in-between the conductor and the silicon surface. After compression bonding, optional heating of the bond above 363 C. allows formation of a liquid gold-silicon eutectic phase containing approximately 3% (by weight) silicon, which significantly improves the bond strength by reforming and enhancing the initial compression bond. The same process can be used for improving the bond strength of Au--Ge bonds by forming a liquid Au-12Ge eutectic phase.

Free-world microelectronic manufacturing equipment

NASA Astrophysics Data System (ADS)

Kilby, J. S.; Arnold, W. H.; Booth, W. T.; Cunningham, J. A.; Hutcheson, J. D.; Owen, R. W.; Runyan, W. R.; McKenney, Barbara L.; McGrain, Moira; Taub, Renee G.

1988-12-01

Equipment is examined and evaluated for the manufacture of microelectronic integrated circuit devices and sources for that equipment within the Free World. Equipment suitable for the following are examined: single-crystal silicon slice manufacturing and processing; required lithographic processes; wafer processing; device packaging; and test of digital integrated circuits. Availability of the equipment is also discussed, now and in the near future. Very adequate equipment for most stages of the integrated circuit manufacturing process is available from several sources, in different countries, although the best and most widely used versions of most manufacturing equipment are made in the United States or Japan. There is also an active market in used equipment, suitable for manufacture of capable integrated circuits with performance somewhat short of the present state of the art.

NASA Electronic Parts and Packaging (NEPP) Program

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Sampson, Michael J.

2008-01-01

This viewgraph presentation reviews NASA's Electronic Parts and Packaging (NEPP) Program. The NEPP mission is to provide guidance to NASA for the selection and and application of microelectronics technologies, to improve understanding of the risks related to the use of these technologies in the space environment and to ensure that appropriate research is performed to meet NASA mission needs. The NEPP Program focuses on the reliability aspects of electronic devices. Three principal aspects to this reliability: (1) lifetime, (2) effects of space radiation and the space environment, and (3) creation and maintenance of the assurance support infrastructure required for success.

The NASA Electronic Parts and Packaging (NEPP) Program: Results and Direction

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.

2007-01-01

The NASA Electronic Parts and Packaging (NEPP) Program's mission is to provide guidance to NASA for the selection and application of microelectronic technologies, to improve understanding of the risks related to the use of these technologies in the space environment and to ensure that appropriate research is performed to meet NASA mission assurance needs. This viewgraph presentation reviews the NEPP program's goals and objectives, and reviews many of the missions that the NEPP program has impacted, both in and out of NASA. Also included are examples of the evaluation that the program performed.

Alpha particle-induced soft errors in microelectronic devices. I

NASA Astrophysics Data System (ADS)

Redman, D. J.; Sega, R. M.; Joseph, R.

1980-03-01

The article provides a tutorial review and trend assessment of the problem of alpha particle-induced soft errors in VLSI memories. Attention is given to an analysis of the design evolution of modern ICs, and the characteristics of alpha particles and their origin in IC packaging are reviewed. Finally, the process of an alpha particle penetrating an IC is examined.

Symmetric miniaturized heating system for active microelectronic devices.

PubMed

McCracken, Michael; Mayer, Michael; Jourard, Isaac; Moon, Jeong-Tak; Persic, John

2010-07-01

To qualify interconnect technologies such as microelectronic fine wire bonds for mass production of integrated circuit (IC) packages, it is necessary to perform accelerated aging tests, e.g., to age a device at an elevated temperature or to subject the device to thermal cycling and measure the decrease of interconnect quality. There are downsides to using conventional ovens for this as they are relatively large and have relatively slow temperature change rates, and if electrical connections are required between monitoring equipment and the device being heated, they must be located inside the oven and may be aged by the high temperatures. Addressing these downsides, a miniaturized heating system (minioven) is presented, which can heat individual IC packages containing the interconnects to be tested. The core of this system is a piece of copper cut from a square shaped tube with high resistance heating wire looped around it. Ceramic dual in-line packages are clamped against either open end of the core. One package contains a Pt100 temperature sensor and the other package contains the device to be aged placed in symmetry to the temperature sensor. According to the temperature detected by the Pt100, a proportional-integral-derivative controller adjusts the power supplied to the heating wire. The system maintains a dynamic temperature balance with the core hot and the two symmetric sides with electrical connections to the device under test at a cooler temperature. Only the face of the package containing the device is heated, while the socket holding it remains below 75 degrees C when the oven operates at 200 degrees C. The minioven can heat packages from room temperature up to 200 degrees C in less than 5 min and maintain this temperature at 28 W power. During long term aging, a temperature of 200 degrees C was maintained for 1120 h with negligible resistance change of the heating wires after 900 h (heating wire resistance increased 0.2% over the final 220 h). The device is also subjected to 5700 thermal cycles between 55 and 195 degrees C, demonstrating reliability under thermal cycling.

How Many Peripheral Solder Joints in a Surface Mounted Design Experience Inelastic Strains?

NASA Astrophysics Data System (ADS)

Suhir, E.; Yi, S.; Ghaffarian, R.

2017-03-01

It has been established that it is the peripheral solder joints that are the most vulnerable in the ball-grid-array (BGA) and column-grid-array (CGA) designs and most often fail. As far as the long-term reliability of a soldered microelectronics assembly as a whole is concerned, it makes a difference, if just one or more peripheral joints experience inelastic strains. It is clear that the low cycle fatigue lifetime of the solder system is inversely proportional to the number of joints that simultaneously experience inelastic strains. A simple and physically meaningful analytical expression (formula) is obtained for the prediction, at the design stage, of the number of such joints, if any, for the given effective thermal expansion (contraction) mismatch of the package and PCB; materials and geometrical characteristics of the package/PCB assembly; package size; and, of course, the level of the yield stress in the solder material. The suggested formula can be used to determine if the inelastic strains in the solder material could be avoided by the proper selection of the above characteristics and, if not, how many peripheral joints are expected to simultaneously experience inelastic strains. The general concept is illustrated by a numerical example carried out for a typical BGA package. The suggested analytical model (formula) is applicable to any soldered microelectronics assembly. The roles of other important factors, such as, e.g., solder material anisotropy, grain size, and their random orientation within a joint, are viewed in this analysis as less important factors than the level of the interfacial stress. The roles of these factors will be accounted for in future work and considered, in addition to the location of the joint, in a more complicated, more sophisticated, and more comprehensive reliability/fatigue model.

Using federal technology policy to strength the US microelectronics industry

NASA Astrophysics Data System (ADS)

Gover, J. E.; Gwyn, C. W.

1994-07-01

A review of US and Japanese experiences with using microelectronics consortia as a tool for strengthening their respective industries reveals major differences. Japan has established catch-up consortia with focused goals. These consortia have a finite life targeted from the beginning, and emphasis is on work that supports or leads to product and process-improvement-driven commercialization. Japan's government has played a key role in facilitating the development of consortia and has used consortia promote domestic competition. US consortia, on the other hand, have often emphasized long-range research with considerably less focus than those in Japan. The US consortia have searched for and often made revolutionary technology advancements. However, technology transfer to their members has been difficult. Only SEMATECH has assisted its members with continuous improvements, compressing product cycles, establishing relationships, and strengthening core competencies. The US government has not been a catalyst nor provided leadership in consortia creation and operation. We propose that in order to regain world leadership in areas where US companies lag foreign competition, the US should create industry-wide, horizontal-vertical, catch-up consortia or continue existing consortia in the six areas where the US lags behind Japan -- optoelectronics, displays, memories, materials, packaging, and manufacturing equipment. In addition, we recommend that consortia be established for special government microelectronics and microelectronics research integration and application. We advocate that these consortia be managed by an industry-led Microelectronics Alliance, whose establishment would be coordinated by the Department of Commerce. We further recommend that the Semiconductor Research Corporation, the National Science Foundation Engineering Research Centers, and relevant elements of other federal programs be integrated into this consortia complex.

Using federal technology policy to strength the US microelectronics industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gover, J.E.; Gwyn, C.W.

1994-07-01

A review of US and Japanese experiences with using microelectronics consortia as a tool for strengthening their respective industries reveals major differences. Japan has established catch-up consortia with focused goals. These consortia have a finite life targeted from the beginning, and emphasis is on work that supports or leads to product and process-improvement-driven commercialization. Japan`s government has played a key role in facilitating the development of consortia and has used consortia promote domestic competition. US consortia, on the other hand, have often emphasized long-range research with considerably less focus than those in Japan. The US consortia have searched for andmore » often made revolutionary technology advancements. However, technology transfer to their members has been difficult. Only SEMATECH has assisted its members with continuous improvements, compressing product cycles, establishing relationships, and strengthening core competencies. The US government has not been a catalyst nor provided leadership in consortia creation and operation. We propose that in order to regain world leadership in areas where US companies lag foreign competition, the US should create industry-wide, horizontal-vertical, catch-up consortia or continue existing consortia in the six areas where the US lags behind Japan -- optoelectronics, displays, memories, materials, packaging, and manufacturing equipment. In addition, we recommend that consortia be established for special government microelectronics and microelectronics research integration and application. We advocate that these consortia be managed by an industry-led Microelectronics Alliance, whose establishment would be coordinated by the Department of Commerce. We further recommend that the Semiconductor Research Corporation, the National Science Foundation Engineering Research Centers, and relevant elements of other federal programs be integrated into this consortia complex.« less

Thermally-Activated Metal-to-Glass Bonding

NASA Technical Reports Server (NTRS)

Gallagher, B. D.

1986-01-01

Hermetic seals formed easily by use of metallo-organic film. Metallo-organic film thermally bonded to glass and soldered or welded to form hermetic seal. Film applied as ink consisting of silver neodecanoate in xylene. Relative amounts of ingredients selected to obtain desired viscosity. Material applied by printing or even by scribing with pen. Sealing technique useful in making solar-cell modules, microelectronic packages, and other hermetic silicon devices.

Microelectronics in Japan

NASA Astrophysics Data System (ADS)

Boulton, William R.

1995-02-01

The purpose of this JTEC study is to evaluate Japan's electronic manufacturing and packaging capabilities within the context of global economic competition. To carry out this study, the JTEC panel evaluated the framework of the Japanese consumer electronics industry and various technological and organizational factors that are likely to determine who will win and lose in the marketplace. This study begins with a brief overview of the electronics industry, especially as it operates in Japan today. Succeeding chapters examine the electronics infrastructure in Japan and take an in-depth look at the central issues of product development in order to identify those parameters that will determine future directions for electronic packaging technologies.

Microelectronics in Japan

NASA Technical Reports Server (NTRS)

Boulton, William R.

1995-01-01

The purpose of this JTEC study is to evaluate Japan's electronic manufacturing and packaging capabilities within the context of global economic competition. To carry out this study, the JTEC panel evaluated the framework of the Japanese consumer electronics industry and various technological and organizational factors that are likely to determine who will win and lose in the marketplace. This study begins with a brief overview of the electronics industry, especially as it operates in Japan today. Succeeding chapters examine the electronics infrastructure in Japan and take an in-depth look at the central issues of product development in order to identify those parameters that will determine future directions for electronic packaging technologies.

Evaluation of advanced microelectronic fluxless solder-bump contacts for hybrid microcircuits

NASA Technical Reports Server (NTRS)

Mandal, R. P.

1976-01-01

Technology for interconnecting monolithic integrated circuit chips with other components is investigated. The advantages and disadvantages of the current flip-chip approach as compared to other interconnection methods are outlined. A fluxless solder-bump contact technology is evaluated. Multiple solder-bump contacts were formed on silicon integrated circuit chips. The solder-bumps, comprised of a rigid nickel under layer and a compliant solder overlayer, were electroformed onto gold device pads with the aid of thick dry film photomasks. Different solder alloys and the use of conductive epoxy for bonding were explored. Fluxless solder-bump bond quality and reliability were evaluated by measuring the effects of centrifuge, thermal cycling, and high temperature storage on bond visual characteristics, bond electrical continuity, and bond shear tests. The applicability and suitability of this technology for hybrid microelectronic packaging is discussed.

Laser Welding in Electronic Packaging

NASA Technical Reports Server (NTRS)

2000-01-01

The laser has proven its worth in numerous high reliability electronic packaging applications ranging from medical to missile electronics. In particular, the pulsed YAG laser is an extremely flexible and versatile too] capable of hermetically sealing microelectronics packages containing sensitive components without damaging them. This paper presents an overview of details that must be considered for successful use of laser welding when addressing electronic package sealing. These include; metallurgical considerations such as alloy and plating selection, weld joint configuration, design of optics, use of protective gases and control of thermal distortions. The primary limitations on use of laser welding electronic for packaging applications are economic ones. The laser itself is a relatively costly device when compared to competing welding equipment. Further, the cost of consumables and repairs can be significant. These facts have relegated laser welding to use only where it presents a distinct quality or reliability advantages over other techniques of electronic package sealing. Because of the unique noncontact and low heat inputs characteristics of laser welding, it is an ideal candidate for sealing electronic packages containing MEMS devices (microelectromechanical systems). This paper addresses how the unique advantages of the pulsed YAG laser can be used to simplify MEMS packaging and deliver a product of improved quality.

Nanoscale temperature mapping in operating microelectronic devices

DOE PAGES

Mecklenburg, Matthew; Hubbard, William A.; White, E. R.; ...

2015-02-05

We report that modern microelectronic devices have nanoscale features that dissipate power nonuniformly, but fundamental physical limits frustrate efforts to detect the resulting temperature gradients. Contact thermometers disturb the temperature of a small system, while radiation thermometers struggle to beat the diffraction limit. Exploiting the same physics as Fahrenheit’s glass-bulb thermometer, we mapped the thermal expansion of Joule-heated, 80-nanometer-thick aluminum wires by precisely measuring changes in density. With a scanning transmission electron microscope (STEM) and electron energy loss spectroscopy (EELS), we quantified the local density via the energy of aluminum’s bulk plasmon. Rescaling density to temperature yields maps with amore » statistical precision of 3 kelvin/hertz ₋1/2, an accuracy of 10%, and nanometer-scale resolution. Lastly, many common metals and semiconductors have sufficiently sharp plasmon resonances to serve as their own thermometers.« less

Adaptive Mesh Refinement for Microelectronic Device Design

NASA Technical Reports Server (NTRS)

Cwik, Tom; Lou, John; Norton, Charles

1999-01-01

Finite element and finite volume methods are used in a variety of design simulations when it is necessary to compute fields throughout regions that contain varying materials or geometry. Convergence of the simulation can be assessed by uniformly increasing the mesh density until an observable quantity stabilizes. Depending on the electrical size of the problem, uniform refinement of the mesh may be computationally infeasible due to memory limitations. Similarly, depending on the geometric complexity of the object being modeled, uniform refinement can be inefficient since regions that do not need refinement add to the computational expense. In either case, convergence to the correct (measured) solution is not guaranteed. Adaptive mesh refinement methods attempt to selectively refine the region of the mesh that is estimated to contain proportionally higher solution errors. The refinement may be obtained by decreasing the element size (h-refinement), by increasing the order of the element (p-refinement) or by a combination of the two (h-p refinement). A successful adaptive strategy refines the mesh to produce an accurate solution measured against the correct fields without undue computational expense. This is accomplished by the use of a) reliable a posteriori error estimates, b) hierarchal elements, and c) automatic adaptive mesh generation. Adaptive methods are also useful when problems with multi-scale field variations are encountered. These occur in active electronic devices that have thin doped layers and also when mixed physics is used in the calculation. The mesh needs to be fine at and near the thin layer to capture rapid field or charge variations, but can coarsen away from these layers where field variations smoothen and charge densities are uniform. This poster will present an adaptive mesh refinement package that runs on parallel computers and is applied to specific microelectronic device simulations. Passive sensors that operate in the infrared portion of the spectrum as well as active device simulations that model charge transport and Maxwell's equations will be presented.

Vision Technology for Automated Inspection of Hybrid Microelectronics Assemblies

DTIC Science & Technology

1988-06-01

circuits are a very efficient packaging technique, with the primary advantages of size, better resistance to environ - 0 ments, and the flexibility to...produced for the military are much more complex and have more stringent performance requirements, particularly in their resistance to environments and...boards, particularly because of the need to protect circuits from a hostile environment such as salt, heat, and moisture. Included among the major U.S

Radiation Testing, Characterization and Qualification Challenges for Modern Microelectronics and Photonics Devices and Technologies

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Cohn, Lewis M.

2008-01-01

At an earlier conference we discussed a selection of the challenges for radiation testing of modern semiconductor devices focusing on state-of-the-art CMOS technologies. In this presentation, we extend this discussion focusing on the following areas: (1) Device packaging, (2) Evolving physical single even upset mechanisms, (3) Device complexity, and (4) the goal of understanding the limitations and interpretation of radiation testing results.

A novel monolithic piezoelectric actuated flexure-mechanism based wire clamp for microelectronic device packaging.

PubMed

Liang, Cunman; Wang, Fujun; Tian, Yanling; Zhao, Xingyu; Zhang, Hongjie; Cui, Liangyu; Zhang, Dawei; Ferreira, Placid

2015-04-01

A novel monolithic piezoelectric actuated wire clamp is presented in this paper to achieve fast, accurate, and robust microelectronic device packaging. The wire clamp has compact, flexure-based mechanical structure and light weight. To obtain large and robust jaw displacements and ensure parallel jaw grasping, a two-stage amplification composed of a homothetic bridge type mechanism and a parallelogram leverage mechanism was designed. Pseudo-rigid-body model and Lagrange approaches were employed to conduct the kinematic, static, and dynamic modeling of the wire clamp and optimization design was carried out. The displacement amplification ratio, maximum allowable stress, and natural frequency were calculated. Finite element analysis (FEA) was conducted to evaluate the characteristics of the wire clamp and wire electro discharge machining technique was utilized to fabricate the monolithic structure. Experimental tests were carried out to investigate the performance and the experimental results match well with the theoretical calculation and FEA. The amplification ratio of the clamp is 20.96 and the working mode frequency is 895 Hz. Step response test shows that the wire clamp has fast response and high accuracy and the motion resolution is 0.2 μm. High speed precision grasping operations of gold and copper wires were realized using the wire clamper.

Contamination control in hybrid microelectronic modules. Part 3: Specifications for coating material and process controls

NASA Technical Reports Server (NTRS)

Himmel, R. P.

1975-01-01

Resin systems for coating hybrids prior to hermetic sealing are described. The resin systems are a flexible silicone junction resin system and a flexible cycloaliphatic epoxy resin system. The coatings are intended for application to the hybrid after all the chips have been assembled and wire bonded, but prior to hermetic sealing of the package. The purpose of the coating is to control particulate contamination by immobilizing particles and by passivating the hybrid. Recommended process controls for the purpose of minimizing contamination in hybrid microcircuit packages are given. Emphasis is placed on those critical hybrid processing steps in which contamination is most likely to occur.

Carbon nanotubes for thermal interface materials in microelectronic packaging

NASA Astrophysics Data System (ADS)

Lin, Wei

As the integration scale of transistors/devices in a chip/system keeps increasing, effective cooling has become more and more important in microelectronics. To address the thermal dissipation issue, one important solution is to develop thermal interface materials with higher performance. Carbon nanotubes, given their high intrinsic thermal and mechanical properties, and their high thermal and chemical stabilities, have received extensive attention from both academia and industry as a candidate for high-performance thermal interface materials. The thesis is devoted to addressing some challenges related to the potential application of carbon nanotubes as thermal interface materials in microelectronics. These challenges include: 1) controlled synthesis of vertically aligned carbon nanotubes on various bulk substrates via chemical vapor deposition and the fundamental understanding involved; 2) development of a scalable annealing process to improve the intrinsic properties of synthesized carbon nanotubes; 3) development of a state-of-art assembling process to effectively implement high-quality vertically aligned carbon nanotubes into a flip-chip assembly; 4) a reliable thermal measurement of intrinsic thermal transport property of vertically aligned carbon nanotube films; 5) improvement of interfacial thermal transport between carbon nanotubes and other materials. The major achievements are summarized. 1. Based on the fundamental understanding of catalytic chemical vapor deposition processes and the growth mechanism of carbon nanotube, fast synthesis of high-quality vertically aligned carbon nanotubes on various bulk substrates (e.g., copper, quartz, silicon, aluminum oxide, etc.) has been successfully achieved. The synthesis of vertically aligned carbon nanotubes on the bulk copper substrate by the thermal chemical vapor deposition process has set a world record. In order to functionalize the synthesized carbon nanotubes while maintaining their good vertical alignment, an in situ functionalization process has for the first time been demonstrated. The in situ functionalization renders the vertically aligned carbon nanotubes a proper chemical reactivity for forming chemical bonding with other substrate materials such as gold and silicon. 2. An ultrafast microwave annealing process has been developed to reduce the defect density in vertically aligned carbon nanotubes. Raman and thermogravimetric analyses have shown a distinct defect reduction in the CNTs annealed in microwave for 3 min. Fibers spun from the as-annealed CNTs, in comparison with those from the pristine CNTs, show increases of ˜35% and ˜65%, respectively, in tensile strength (˜0.8 GPa) and modulus (˜90 GPa) during tensile testing; an ˜20% improvement in electrical conductivity (˜80000 S m-1) was also reported. The mechanism of the microwave response of CNTs was discussed. Such a microwave annealing process has been extended to the preparation of reduced graphene oxide. 3. Based on the fundamental understanding of interfacial thermal transport and surface chemistry of metals and carbon nanotubes, two major transfer/assembling processes have been developed: molecular bonding and metal bonding. Effective improvement of the interfacial thermal transport has been achieved by the interfacial bonding. 4. The thermal diffusivity of vertically aligned carbon nanotube (VACNT, multi-walled) films was measured by a laser flash technique, and shown to be ˜30 mm2 s-1 along the tube-alignment direction. The calculated thermal conductivities of the VACNT film and the individual CNTs are ˜27 and ˜540 W m-1 K-1, respectively. The technique was verified to be reliable although a proper sampling procedure is critical. A systematic parametric study of the effects of defects, buckling, tip-to-tip contacts, packing density, and tube-tube interaction on the thermal diffusivity was carried out. Defects and buckling decreased the thermal diffusivity dramatically. An increased packing density was beneficial in increasing the collective thermal conductivity of the VACNT film; however, the increased tube-tube interaction in dense VACNT films decreased the thermal conductivity of the individual CNTs. The tip-to-tip contact resistance was shown to be ˜1x10-7 m2 K W -1. The study will shed light on the potential application of VACNTs as thermal interface materials in microelectronic packaging. 5. A combined process of in situ functionalization and microwave curing has been developed to effective enhance the interface between carbon nanotubes and the epoxy matrix. Effective medium theory has been used to analyze the interfacial thermal resistance between carbon nanotubes and polymer matrix, and that between graphite nanoplatlets and polymer matrix.

The demise of plastic encapsulated microcircuit myths

NASA Astrophysics Data System (ADS)

Hakim, E. B.; Agarwal, R. K.; Pecht, M.

1994-10-01

Production of microelectronic devices encapsulated in solid, molded plastic packages has rapidly increased since the early 1980's. Today, millions of plastic-encapsulated devices are produced daily. On the other hand, only a few million hermetic (cavity) packages are produced per year. Reasons for the increased use of plastic-encapsulated packages include cost, availability, size, weight, quality, and reliability. Markets taking advantage of this technology range from computers and telecommunications to automotive uses. Yet, several industries, the military in particular, will not accept such devices. One reason for this reluctance to use the best available commercial parts is a perceived risk of poor reliability, derived from antiquated military specifications, standards, and handbooks; other common justifications cite differing environments; inadequate screens; inadequate test data, and required government audits of suppliers' processes. This paper describes failure mechanisms associated with plastic encapsulation and their elimination. It provides data indicating the relative reliability of cavity and solid-encapsulated packaging, and presents possible approaches to assuring quality and reliability in the procuring and applying this successful commercial technology.

Defect Inspection of Flip Chip Solder Bumps Using an Ultrasonic Transducer

PubMed Central

Su, Lei; Shi, Tielin; Xu, Zhensong; Lu, Xiangning; Liao, Guanglan

2013-01-01

Surface mount technology has spurred a rapid decrease in the size of electronic packages, where solder bump inspection of surface mount packages is crucial in the electronics manufacturing industry. In this study we demonstrate the feasibility of using a 230 MHz ultrasonic transducer for nondestructive flip chip testing. The reflected time domain signal was captured when the transducer scanning the flip chip, and the image of the flip chip was generated by scanning acoustic microscopy. Normalized cross-correlation was used to locate the center of solder bumps for segmenting the flip chip image. Then five features were extracted from the signals and images. The support vector machine was adopted to process the five features for classification and recognition. The results show the feasibility of this approach with high recognition rate, proving that defect inspection of flip chip solder bumps using the ultrasonic transducer has high potential in microelectronics packaging.

Contamination control in hybrid microelectronic modules. Part 2: Selection and evaluation of coating materials

NASA Technical Reports Server (NTRS)

Himmel, R. P.

1975-01-01

The selection, test, and evaluation of organic coating materials for contamination control in hybrid circuits is reported. The coatings were evaluated to determine their suitability for use as a conformal coating over the hybrid microcircuit (including chips and wire bonds) inside a hermetically sealed package. Evaluations included ease of coating application and repair and effect on thin film and thick film resistors, beam leads, wire bonds, transistor chips, and capacitor chips. The coatings were also tested for such properties as insulation resistance, voltage breakdown strength, and capability of immobilizing loose particles inside the packages. The selected coatings were found to be electrically, mechanically, and chemically compatible with all components and materials normally used in hybrid microcircuits.

RADIANCE PROCESS EVALUATION FOR PARTICLE REMOVAL

EPA Science Inventory

The microelectronics industry (wafer, flat panel displays, photomasks, and storage media) is transitioning to higher device densities and larger substrate formats. These changes will challenge standard cleaning methods and will require significant increases to the fabricator inf...

Development Of A Three-Dimensional Circuit Integration Technology And Computer Architecture

NASA Astrophysics Data System (ADS)

Etchells, R. D.; Grinberg, J.; Nudd, G. R.

1981-12-01

This paper is the first of a series 1,2,3 describing a range of efforts at Hughes Research Laboratories, which are collectively referred to as "Three-Dimensional Microelectronics." The technology being developed is a combination of a unique circuit fabrication/packaging technology and a novel processing architecture. The packaging technology greatly reduces the parasitic impedances associated with signal-routing in complex VLSI structures, while simultaneously allowing circuit densities orders of magnitude higher than the current state-of-the-art. When combined with the 3-D processor architecture, the resulting machine exhibits a one- to two-order of magnitude simultaneous improvement over current state-of-the-art machines in the three areas of processing speed, power consumption, and physical volume. The 3-D architecture is essentially that commonly referred to as a "cellular array", with the ultimate implementation having as many as 512 x 512 processors working in parallel. The three-dimensional nature of the assembled machine arises from the fact that the chips containing the active circuitry of the processor are stacked on top of each other. In this structure, electrical signals are passed vertically through the chips via thermomigrated aluminum feedthroughs. Signals are passed between adjacent chips by micro-interconnects. This discussion presents a broad view of the total effort, as well as a more detailed treatment of the fabrication and packaging technologies themselves. The results of performance simulations of the completed 3-D processor executing a variety of algorithms are also presented. Of particular pertinence to the interests of the focal-plane array community is the simulation of the UNICORNS nonuniformity correction algorithms as executed by the 3-D architecture.

Pre-release plastic packaging of MEMS and IMEMS devices

DOEpatents

Peterson, Kenneth A.; Conley, William R.

2002-01-01

A method is disclosed for pre-release plastic packaging of MEMS and IMEMS devices. The method can include encapsulating the MEMS device in a transfer molded plastic package. Next, a perforation can be made in the package to provide access to the MEMS elements. The non-ablative material removal process can include wet etching, dry etching, mechanical machining, water jet cutting, and ultrasonic machining, or any combination thereof. Finally, the MEMS elements can be released by using either a wet etching or dry plasma etching process. The MEMS elements can be protected with a parylene protective coating. After releasing the MEMS elements, an anti-stiction coating can be applied. The perforating step can be applied to both sides of the device or package. A cover lid can be attached to the face of the package after releasing any MEMS elements. The cover lid can include a window for providing optical access. The method can be applied to any plastic packaged microelectronic device that requires access to the environment, including chemical, pressure, or temperature-sensitive microsensors; CCD chips, photocells, laser diodes, VCSEL's, and UV-EPROMS. The present method places the high-risk packaging steps ahead of the release of the fragile portions of the device. It also provides protection for the die in shipment between the molding house and the house that will release the MEMS elements and subsequently treat the surfaces.

An introduction to NASA's advanced computing program: Integrated computing systems in advanced multichip modules

NASA Technical Reports Server (NTRS)

Fang, Wai-Chi; Alkalai, Leon

1996-01-01

Recent changes within NASA's space exploration program favor the design, implementation, and operation of low cost, lightweight, small and micro spacecraft with multiple launches per year. In order to meet the future needs of these missions with regard to the use of spacecraft microelectronics, NASA's advanced flight computing (AFC) program is currently considering industrial cooperation and advanced packaging architectures. In relation to this, the AFC program is reviewed, considering the design and implementation of NASA's AFC multichip module.

Development of a qualification standard for adhesives used in hybrid microcircuits

NASA Technical Reports Server (NTRS)

Licari, J. J.; Weigand, B. L.; Soykin, C. A.

1981-01-01

Improved qualification standards and test procedures for adhesives used in microelectronic packaging are developed. The test methods in specification for the Selection and Use of Organic Adhesives in Hybrid Microcircuits are reevaluated versus industry and government requirements. Four electrically insulative and four electrically conductive adhesives used in the assembly of hybrid microcircuits are selected to evaluate the proposed revised test methods. An estimate of the cost to perform qualification testing of an adhesive to the requirements of the revised specification is also prepared.

Investigation of discrete component chip mounting technology for hybrid microelectronic circuits

NASA Technical Reports Server (NTRS)

Caruso, S. V.; Honeycutt, J. O.

1975-01-01

The use of polymer adhesives for high reliability microcircuit applications is a radical deviation from past practices in electronic packaging. Bonding studies were performed using two gold-filled conductive adhesives, 10/90 tin/lead solder and Indalloy no. 7 solder. Various types of discrete components were mounted on ceramic substrates using both thick-film and thin-film metallization. Electrical and mechanical testing were performed on the samples before and after environmental exposure to MIL-STD-883 screening tests.

Millimeter-wave MMIC technology for smart weapons

NASA Astrophysics Data System (ADS)

Seashore, Charles R.

1994-12-01

Millimeter wave MMIC component technology has made dramatic progress over the last ten years largely due to funding stimulation received under the ARPA Tri-Service MIMIC program. In several smart weapon systems, MMIC components are now specified as the baseline approach for millimeter wave radar transceiver hardware. Availability of this new frontier in microelectronics has also enabled realization of sensor fusion for multispectral capability to defeat many forms of known countermeasures. The current frequency range for these MMIC-based components is approximately 30 to 100 GHz. In several cases, it has been demonstrated that the MMIC component performance has exceeded that available from hybrid microstrip circuits using selected discrete devices. However, challenges still remain in chip producibility enhancement and cost reduction since many of the essential device structure candidates are themselves emerging technologies with a limited wafer fabrication history and accumulated test databases. It is concluded that smart weapons of the future will rely heavily on advanced microelectronics to satisfy performance requirements as well as meeting stringent packaging and power source constraints.

Utilization of Pb-free solders in MEMS packaging

NASA Astrophysics Data System (ADS)

Selvaduray, Guna S.

2003-01-01

Soldering of components within a package plays an important role in providing electrical interconnection, mechanical integrity and thermal dissipation. MEMS packages present challenges that are more complex than microelectronic packages because they are far more sensitive to shock and vibration and also require precision alignment. Soldering is used at two major levels within a MEMS package: at the die attach level and at the component attach level. Emerging environmental regulations worldwide, notably in Europe and Japan, have targeted the elimination of Pb usage in electronic assemblies, due to the inherent toxicity of Pb. This has provided the driving force for development and deployment of Pb-free solder alloys. A relatively large number of Pb-free solder alloys have been proposed by various researchers and companies. Some of these alloys have also been patented. After several years of research, the solder alloy system that has emerged is based on Sn as a major component. The electronics industry has identified different compositions for different specific uses, such as wave soldering, surface mount reflow, etc. The factors that affect choice of an appropriate Pb-free solder can be divided into two major categories, those related to manufacturing, and those related to long term reliability and performance.

Three-dimensional direct laser written graphitic electrical contacts to randomly distributed components

NASA Astrophysics Data System (ADS)

Dorin, Bryce; Parkinson, Patrick; Scully, Patricia

2018-04-01

The development of cost-effective electrical packaging for randomly distributed micro/nano-scale devices is a widely recognized challenge for fabrication technologies. Three-dimensional direct laser writing (DLW) has been proposed as a solution to this challenge, and has enabled the creation of rapid and low resistance graphitic wires within commercial polyimide substrates. In this work, we utilize the DLW technique to electrically contact three fully encapsulated and randomly positioned light-emitting diodes (LEDs) in a one-step process. The resolution of the contacts is in the order of 20 μ m, with an average circuit resistance of 29 ± 18 kΩ per LED contacted. The speed and simplicity of this technique is promising to meet the needs of future microelectronics and device packaging.

Standard semiconductor packaging for high-reliability low-cost MEMS applications

NASA Astrophysics Data System (ADS)

Harney, Kieran P.

2005-01-01

Microelectronic packaging technology has evolved over the years in response to the needs of IC technology. The fundamental purpose of the package is to provide protection for the silicon chip and to provide electrical connection to the circuit board. Major change has been witnessed in packaging and today wafer level packaging technology has further revolutionized the industry. MEMS (Micro Electro Mechanical Systems) technology has created new challenges for packaging that do not exist in standard ICs. However, the fundamental objective of MEMS packaging is the same as traditional ICs, the low cost and reliable presentation of the MEMS chip to the next level interconnect. Inertial MEMS is one of the best examples of the successful commercialization of MEMS technology. The adoption of MEMS accelerometers for automotive airbag applications has created a high volume market that demands the highest reliability at low cost. The suppliers to these markets have responded by exploiting standard semiconductor packaging infrastructures. However, there are special packaging needs for MEMS that cannot be ignored. New applications for inertial MEMS devices are emerging in the consumer space that adds the imperative of small size to the need for reliability and low cost. These trends are not unique to MEMS accelerometers. For any MEMS technology to be successful the packaging must provide the basic reliability and interconnection functions, adding the least possible cost to the product. This paper will discuss the evolution of MEMS packaging in the accelerometer industry and identify the main issues that needed to be addressed to enable the successful commercialization of the technology in the automotive and consumer markets.

Standard semiconductor packaging for high-reliability low-cost MEMS applications

NASA Astrophysics Data System (ADS)

Harney, Kieran P.

2004-12-01

Microelectronic packaging technology has evolved over the years in response to the needs of IC technology. The fundamental purpose of the package is to provide protection for the silicon chip and to provide electrical connection to the circuit board. Major change has been witnessed in packaging and today wafer level packaging technology has further revolutionized the industry. MEMS (Micro Electro Mechanical Systems) technology has created new challenges for packaging that do not exist in standard ICs. However, the fundamental objective of MEMS packaging is the same as traditional ICs, the low cost and reliable presentation of the MEMS chip to the next level interconnect. Inertial MEMS is one of the best examples of the successful commercialization of MEMS technology. The adoption of MEMS accelerometers for automotive airbag applications has created a high volume market that demands the highest reliability at low cost. The suppliers to these markets have responded by exploiting standard semiconductor packaging infrastructures. However, there are special packaging needs for MEMS that cannot be ignored. New applications for inertial MEMS devices are emerging in the consumer space that adds the imperative of small size to the need for reliability and low cost. These trends are not unique to MEMS accelerometers. For any MEMS technology to be successful the packaging must provide the basic reliability and interconnection functions, adding the least possible cost to the product. This paper will discuss the evolution of MEMS packaging in the accelerometer industry and identify the main issues that needed to be addressed to enable the successful commercialization of the technology in the automotive and consumer markets.

Quantifying Electromigration Processes in Sn-0.7Cu Solder with Lab-Scale X-Ray Computed Micro-Tomography

NASA Astrophysics Data System (ADS)

Mertens, James Charles Edwin

For decades, microelectronics manufacturing has been concerned with failures related to electromigration phenomena in conductors experiencing high current densities. The influence of interconnect microstructure on device failures related to electromigration in BGA and flip chip solder interconnects has become a significant interest with reduced individual solder interconnect volumes. A survey indicates that x-ray computed micro-tomography (muXCT) is an emerging, novel means for characterizing the microstructures' role in governing electromigration failures. This work details the design and construction of a lab-scale muXCT system to characterize electromigration in the Sn-0.7Cu lead-free solder system by leveraging in situ imaging. In order to enhance the attenuation contrast observed in multi-phase material systems, a modeling approach has been developed to predict settings for the controllable imaging parameters which yield relatively high detection rates over the range of x-ray energies for which maximum attenuation contrast is expected in the polychromatic x-ray imaging system. In order to develop this predictive tool, a model has been constructed for the Bremsstrahlung spectrum of an x-ray tube, and calculations for the detector's efficiency over the relevant range of x-ray energies have been made, and the product of emitted and detected spectra has been used to calculate the effective x-ray imaging spectrum. An approach has also been established for filtering 'zinger' noise in x-ray radiographs, which has proven problematic at high x-ray energies used for solder imaging. The performance of this filter has been compared with a known existing method and the results indicate a significant increase in the accuracy of zinger filtered radiographs. The obtained results indicate the conception of a powerful means for the study of failure causing processes in solder systems used as interconnects in microelectronic packaging devices. These results include the volumetric quantification of parameters which are indicative of both electromigration tolerance of solders and the dominant mechanisms for atomic migration in response to current stressing. This work is aimed to further the community's understanding of failure-causing electromigration processes in industrially relevant material systems for microelectronic interconnect applications and to advance the capability of available characterization techniques for their interrogation.

Special Section on InterPACK 2017—Part 1

DOE PAGES

Mysore, Kaushik; Narumanchi, Sreekant; Dede, Ercan; ...

2018-03-02

InterPACK is a premier international forum for exchange of state-of-the-art knowledge in research, development, manufacturing, and applications of micro-electronics packaging. It is the flagship conference of the ASME Electronic and Photonic Packaging Division (EPPD) founded in 1992 as an ASME-JSME joint biannual conference. Rapid changes in the semiconductor landscape together with findings from InterPACK Pathfinding workshop (IPW) in 2016 led to a significant reset of InterPACK conference priorities and focus to comprehensively address needs of the InterPACK community. As a result, starting in 2017, InterPACK has become an annual conference and the scope of the conference has increased significantly togethermore » with a systems-focus to include some of the most cutting-edge topics in electronics packaging, device integration, and reliability. These topics are organized across five different tracks: (1) heterogeneous integration: microsystems with diverse functionality, (2) servers of the future, (3) structural and physical health monitoring, (4) energy conversion and storage, and (5) transportation: autonomous and electric vehicles.« less

Special Section on InterPACK 2017—Part 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mysore, Kaushik; Narumanchi, Sreekant; Dede, Ercan

InterPACK is a premier international forum for exchange of state-of-the-art knowledge in research, development, manufacturing, and applications of micro-electronics packaging. It is the flagship conference of the ASME Electronic and Photonic Packaging Division (EPPD) founded in 1992 as an ASME-JSME joint biannual conference. Rapid changes in the semiconductor landscape together with findings from InterPACK Pathfinding workshop (IPW) in 2016 led to a significant reset of InterPACK conference priorities and focus to comprehensively address needs of the InterPACK community. As a result, starting in 2017, InterPACK has become an annual conference and the scope of the conference has increased significantly togethermore » with a systems-focus to include some of the most cutting-edge topics in electronics packaging, device integration, and reliability. These topics are organized across five different tracks: (1) heterogeneous integration: microsystems with diverse functionality, (2) servers of the future, (3) structural and physical health monitoring, (4) energy conversion and storage, and (5) transportation: autonomous and electric vehicles.« less

Guest Editorial: Special Section on InterPACK 2017 - Part 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narumanchi, Sreekant V; Mysore, Kaushik; Dede, Ercan

InterPACK is a premier international forum for exchange of state-of-the-art knowledge in research, development, manufacturing, and applications of micro-electronics packaging. It is the flagship conference of the ASME Electronic and Photonic Packaging Division (EPPD) founded in 1992 as an ASME-JSME joint biannual conference. Rapid changes in the semiconductor landscape together with findings from InterPACK Pathfinding workshop (IPW) in 2016 led to a significant reset of InterPACK conference priorities and focus to comprehensively address needs of the InterPACK community. As a result, starting in 2017, InterPACK has become an annual conference and the scope of the conference has increased significantly togethermore » with a systems-focus to include some of the most cutting-edge topics in electronics packaging, device integration, and reliability. These topics are organized across five different tracks: (1) heterogeneous integration: microsystems with diverse functionality, (2) servers of the future, (3) structural and physical health monitoring, (4) energy conversion and storage, and (5) transportation: autonomous and electric vehicles.« less

Contamination Control in Hybrid Microelectronic Modules. Part 1: Identification of Critical Process and Contaminants

NASA Technical Reports Server (NTRS)

Himmel, R. P.

1975-01-01

Various hybrid processing steps, handling procedures, and materials are examined in an attempt to identify sources of contamination and to propose methods for the control of these contaminants. It is found that package sealing, assembly, and rework are especially susceptible to contamination. Moisture and loose particles are identified as the worst contaminants. The points at which contaminants are most likely to enter the hybrid package are also identified, and both general and specific methods for their detection and control are developed. In general, the most effective controls for contaminants are: clean working areas, visual inspection at each step of the process, and effective cleaning at critical process steps. Specific methods suggested include the detection of loose particles by a precap visual inspection, by preseal and post-seal electrical testing, and by a particle impact noise test. Moisture is best controlled by sealing all packages in a clean, dry, inert atmosphere after a thorough bake-out of all parts.

Aeroflex Technology as Class-Y Demonstrator

NASA Technical Reports Server (NTRS)

Suh, Jong-ook; Agarwal, Shri; Popelar, Scott

2014-01-01

Modern space field programmable gate array (FPGA) devices with increased functional density and operational frequency, such as Xilinx Virtex 4 (V4) and S (V5), are packaged in non-hermetic ceramic flip chip forms. These next generation space parts were not qualified to the MIL-PRF-38535 Qualified Manufacturer Listing (QML) class-V when they were released because class-V was only intended for hermetic parts. In order to bring Xilinx V5 type packages into the QML system, it was suggested that class-Y be set up as a new category. From 2010 through 2014, a JEDEC G12 task group developed screening and qualification requirements for Class-Y products. The Document Standardization Division of the Defense Logistics Agency (DLA) has completed an engineering practice study. In parallel with the class-Y efforts, the NASA Electronic Parts and Packaging (NEPP) program has funded JPL to study potential reliability issues of the class-Y products. The major hurdle of this task was the absence of adequate research samples. Figure 1-1 shows schematic diagrams of typical structures of class-Y type products. Typically, class-Y products are either in ceramic flip chip column grid array (CGA) or land grid array (LGA) form. In class-Y packages, underfill and heat spread adhesive materials are directly exposed to the spacecraft environment due to their non-hermeticity. One of the concerns originally raised was that the underfill material could degrade due to the spacecraft environment and negatively impact the reliability of the package. In order to study such issues, it was necessary to use ceramic daisy chain flip chip package samples so that continuity of flip chip solder bumps could be monitored during the reliability tests. However, none of the commercially available class-Y daisy chain parts had electrical connections through flip chip solder bumps; only solder columns were daisy chained, which made it impossible to test continuity of flip chip solder bumps without using extremely costly functional parts. Among space parts manufacturers who were interested in producing class-Y products, Aeroflex Microelectronic Solutions-HiRel had been developing assembly processes using their internal R&D classy type samples. In early 2012, JPL and Aeroflex initiated a collaboration to study reliability of the Aeroflex technology as a class-Y demonstrator.

Micro-Scale Avionics Thermal Management

NASA Technical Reports Server (NTRS)

Moran, Matthew E.

2001-01-01

Trends in the thermal management of avionics and commercial ground-based microelectronics are converging, and facing the same dilemma: a shortfall in technology to meet near-term maximum junction temperature and package power projections. Micro-scale devices hold the key to significant advances in thermal management, particularly micro-refrigerators/coolers that can drive cooling temperatures below ambient. A microelectromechanical system (MEMS) Stirling cooler is currently under development at the NASA Glenn Research Center to meet this challenge with predicted efficiencies that are an order of magnitude better than current and future thermoelectric coolers.

Piezoelectric-nanowire-enabled power source for driving wireless microelectronics.

PubMed

Xu, Sheng; Hansen, Benjamin J; Wang, Zhong Lin

2010-10-19

Harvesting energy from irregular/random mechanical actions in variable and uncontrollable environments is an effective approach for powering wireless mobile electronics to meet a wide range of applications in our daily life. Piezoelectric nanowires are robust and can be stimulated by tiny physical motions/disturbances over a range of frequencies. Here, we demonstrate the first chemical epitaxial growth of PbZr(x)Ti(1-x)O(3) (PZT) nanowire arrays at 230 °C and their application as high-output energy converters. The nanogenerators fabricated using a single array of PZT nanowires produce a peak output voltage of ~0.7 V, current density of 4 μA cm(-2) and an average power density of 2.8 mW cm(-3). The alternating current output of the nanogenerator is rectified, and the harvested energy is stored and later used to light up a commercial laser diode. This work demonstrates the feasibility of using nanogenerators for powering mobile and even personal microelectronics.

Trends in Dielectric Etch for Microelectronics Processing

NASA Astrophysics Data System (ADS)

Hudson, Eric A.

2003-10-01

Dielectric etch technology faces many challenges to meet the requirements for leading-edge microelectronics processing. The move to sub 100-nm device design rules increases the aspect ratios of certain features, imposes tighter restrictions on etched features' critical dimensions, and increases the density of closely packed arrays of features. Changes in photolithography are driving transitions to new photoresist materials and novel multilayer resist methods. The increasing use of copper metallization and low-k interlayer dielectric materials has introduced dual-damascene integration methods, with specialized dielectric etch applications. A common need is the selective removal of multiple layers which have very different compositions, while maintaining close control of the etched features' profiles. To increase productivity, there is a growing trend toward in-situ processing, which allows several films to be successively etched during a single pass through the process module. Dielectric etch systems mainly utilize capacitively coupled etch reactors, operating with medium-density plasmas and low gas residence time. Commercial technology development increasingly relies upon plasma diagnostics and modeling to reduce development cycle time and maximize performance.

The Assurance Challenges of Advanced Packaging Technologies for Electronics

NASA Technical Reports Server (NTRS)

Sampson, Michael J.

2010-01-01

Advances in microelectronic parts performance are driving towards finer feature sizes, three-dimensional geometries and ever-increasing number of transistor equivalents that are resulting in increased die sizes and interconnection (I/O) counts. The resultant packaging necessary to provide assemble-ability, environmental protection, testability and interconnection to the circuit board for the active die creates major challenges, particularly for space applications, Traditionally, NASA has used hermetically packaged microcircuits whenever available but the new demands make hermetic packaging less and less practical at the same time as more and more expensive, Some part types of great interest to NASA designers are currently only available in non-hermetic packaging. It is a far more complex quality and reliability assurance challenge to gain confidence in the long-term survivability and effectiveness of nonhermetic packages than for hermetic ones. Although they may provide more rugged environmental protection than the familiar Plastic Encapsulated Microcircuits (PEMs), the non-hermetic Ceramic Column Grid Array (CCGA) packages that are the focus of this presentation present a unique combination of challenges to assessing their suitability for spaceflight use. The presentation will discuss the bases for these challenges, some examples of the techniques proposed to mitigate them and a proposed approach to a US MIL specification Class for non-hermetic microcircuits suitable for space application, Class Y, to be incorporated into M. IL-PRF-38535. It has recently emerged that some major packaging suppliers are offering hermetic area array packages that may offer alternatives to the nonhermetic CCGA styles but have also got their own inspectability and testability issues which will be briefly discussed in the presentation,

Soft-Matter Printed Circuit Board with UV Laser Micropatterning.

PubMed

Lu, Tong; Markvicka, Eric J; Jin, Yichu; Majidi, Carmel

2017-07-05

When encapsulated in elastomer, micropatterned traces of Ga-based liquid metal (LM) can function as elastically deformable circuit wiring that provides mechanically robust electrical connectivity between solid-state elements (e.g., transistors, processors, and sensor nodes). However, LM-microelectronics integration is currently limited by challenges in rapid fabrication of LM circuits and the creation of vias between circuit terminals and the I/O pins of packaged electronics. In this study, we address both with a unique layup for soft-matter electronics in which traces of liquid-phase Ga-In eutectic (EGaIn) are patterned with UV laser micromachining (UVLM). The terminals of the elastomer-sealed LM circuit connect to the surface mounted chips through vertically aligned columns of EGaIn-coated Ag-Fe 2 O 3 microparticles that are embedded within an interfacial elastomer layer. The processing technique is compatible with conventional UVLM printed circuit board (PCB) prototyping and exploits the photophysical ablation of EGaIn on an elastomer substrate. Potential applications to wearable computing and biosensing are demonstrated with functional implementations in which soft-matter PCBs are populated with surface-mounted microelectronics.

Method of fabricating free-form, high-aspect ratio components for high-current, high-speed microelectrics

DOEpatents

Maxwell, James L; Rose, Chris R; Black, Marcie R; Springer, Robert W

2014-03-11

Microelectronic structures and devices, and method of fabricating a three-dimensional microelectronic structure is provided, comprising passing a first precursor material for a selected three-dimensional microelectronic structure into a reaction chamber at temperatures sufficient to maintain said precursor material in a predominantly gaseous state; maintaining said reaction chamber under sufficient pressures to enhance formation of a first portion of said three-dimensional microelectronic structure; applying an electric field between an electrode and said microelectronic structure at a desired point under conditions whereat said first portion of a selected three-dimensional microelectronic structure is formed from said first precursor material; positionally adjusting either said formed three-dimensional microelectronic structure or said electrode whereby further controlled growth of said three-dimensional microelectronic structure occurs; passing a second precursor material for a selected three-dimensional microelectronic structure into a reaction chamber at temperatures sufficient to maintain said precursor material in a predominantly gaseous state; maintaining said reaction chamber under sufficient pressures whereby a second portion of said three-dimensional microelectronic structure formation is enhanced; applying an electric field between an electrode and said microelectronic structure at a desired point under conditions whereat said second portion of a selected three-dimensional microelectronic structure is formed from said second precursor material; and, positionally adjusting either said formed three-dimensional microelectronic structure or said electrode whereby further controlled growth of said three-dimensional microelectronic structure occurs.

Decapsulation Method for Flip Chips with Ceramics in Microelectronic Packaging

NASA Astrophysics Data System (ADS)

Shih, T. I.; Duh, J. G.

2008-06-01

The decapsulation of flip chips bonded to ceramic substrates is a challenging task in the packaging industry owing to the vulnerability of the chip surface during the process. In conventional methods, such as manual grinding and polishing, the solder bumps are easily damaged during the removal of underfill, and the thin chip may even be crushed due to mechanical stress. An efficient and reliable decapsulation method consisting of thermal and chemical processes was developed in this study. The surface quality of chips after solder removal is satisfactory for the existing solder rework procedure as well as for die-level failure analysis. The innovative processes included heat-sink and ceramic substrate removal, solder bump separation, and solder residue cleaning from the chip surface. In the last stage, particular temperatures were selected for the removal of eutectic Pb-Sn, high-lead, and lead-free solders considering their respective melting points.

MEMS in Space Systems

NASA Technical Reports Server (NTRS)

Lyke, J. C.; Michalicek, M. A.; Singaraju, B. K.

1995-01-01

Micro-electro-mechanical systems (MEMS) provide an emerging technology that has the potential for revolutionizing the way space systems are designed, assembled, and tested. The high launch costs of current space systems are a major determining factor in the amount of functionality that can be integrated in a typical space system. MEMS devices have the ability to increase the functionality of selected satellite subsystems while simultaneously decreasing spacecraft weight. The Air Force Phillips Laboratory (PL) is supporting the development of a variety of MEMS related technologies as one of several methods to reduce the weight of space systems and increase their performance. MEMS research is a natural extension of PL research objectives in micro-electronics and advanced packaging. Examples of applications that are under research include on-chip micro-coolers, micro-gyroscopes, vibration sensors, and three-dimensional packaging technologies to integrate electronics with MEMS devices. The first on-orbit space flight demonstration of these and other technologies is scheduled for next year.

Radiation Testing, Characterization and Qualification Challenges for Modern Microelectronics and Photonics Devices and Technologies

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Cohn, Lewis M.

2008-01-01

At GOMAC 2007, we discussed a selection of the challenges for radiation testing of modern semiconductor devices focusing on state-of-the-art memory technologies. This included FLASH non-volatile memories (NVMs) and synchronous dynamic random access memories (SDRAMs). In this presentation, we extend this discussion in device packaging and complexity as well as single event upset (SEU) mechanisms using several technology areas as examples including: system-on-a-chip (SOC) devices and photonic or fiber optic systems. The underlying goal is intended to provoke thought for understanding the limitations and interpretation of radiation testing results.

2011 NRL REVIEW

DTIC Science & Technology

2011-01-01

other mechanism ? What accelerates the solar wind? What are the near- Sun plasma properties (particle density, magnetic field)? Does the solar wind come...microstructure character iza tion, elec tronic ceramics, solid-state physics, fiber optics, electro-optics, microelectronics, fracture mechan ics...computational fluid mechanics , experi mental structural mechanics , solid me chan ics, elastic/plastic fracture mechanics , materials, finite-element

Thermal and Electrical Characterization of Alumina Substrate for Microelectronic Applications

NASA Astrophysics Data System (ADS)

Ahmad, S.; Ibrahim, A.; Alias, R.; Shapee, S. M.; Ambak, Z.; Zakaria, S. Z.; Yahya, M. R.; Mat, A. F. A.

2010-03-01

This paper reports the effect of sintering temperature on thermal and electrical properties of alumina material as substrate for microelectronic devices. Alumina materials in the form of green sheet with 1 mm thickness were sintered at 1100° C, 1300° C and 1500° C for about 20 hours using heating and cooling rates of 2° C/min. The densities were measured using densitometer and the microstructures of the samples were analyzed using SEM micrographs. Meanwhile thermal and electrical properties of the samples were measured using flash method and impedance analyzer respectively. It was found that thermal conductivity and thermal diffusivity of the substrate increases as sintering temperature increases. It was found also that the dielectric constant of alumina substrate increases as the sintering temperature increases.

Semiconductor Metal-Organic Frameworks: Future Low-Bandgap Materials.

PubMed

Usman, Muhammad; Mendiratta, Shruti; Lu, Kuang-Lieh

2017-02-01

Metal-organic frameworks (MOFs) with low density, high porosity, and easy tunability of functionality and structural properties, represent potential candidates for use as semiconductor materials. The rapid development of the semiconductor industry and the continuous miniaturization of feature sizes of integrated circuits toward the nanometer (nm) scale require novel semiconductor materials instead of traditional materials like silicon, germanium, and gallium arsenide etc. MOFs with advantageous properties of both the inorganic and the organic components promise to serve as the next generation of semiconductor materials for the microelectronics industry with the potential to be extremely stable, cheap, and mechanically flexible. Here, a perspective of recent research is provided, regarding the semiconducting properties of MOFs, bandgap studies, and their potential in microelectronic devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nano-Satellite Avionics

NASA Technical Reports Server (NTRS)

Culver, Harry

1999-01-01

Abstract NASA's Goddard Space Flight Center (GSFC) is currently developing a new class of satellites called the nano-satellite (nano-sat). A major objective of this development effort is to provide the technology required to enable a constellation of tens to hundreds of nano-satellites to make both remote and in-situ measurements from space. The Nano-sat will be a spacecraft weighing a maximum of 10 kg, including the propellant mass, and producing at least 5 Watts of power to operate the spacecraft. The electronics are required to survive a total radiation dose rate of 100 krads for a mission lifetime of two years. There are many unique challenges that must be met in order to develop the avionics for such a spacecraft. The first challenge is to develop an architecture that will operate on the allotted 5 Watts and meet the diverging requirements of multiple missions. This architecture will need to incorporate a multitude of new advanced microelectronic technologies. The microelectronics developed must be a modular and scalable packaging of technology to solve the problem of developing a solution to both reduce cost and meet the requirements of various missions. This development will utilize the most cost effective approach, whether infusing commercially driven semiconductor devices into spacecraft applications or partnering with industry to design and develop low cost, low power, low mass, and high capacity data processing devices. This paper will discuss the nano-sat architecture and the major technologies that will be developed. The major technologies that will be covered include: (1) Light weight Low Power Electronics Packaging, (2) Radiation Hard/Tolerant, Low Power Processing Platforms, (3) High capacity Low Power Memory Systems (4) Radiation Hard reconfiguragble field programmable gate array (rFPGA)

Molecular Design of Low-Density Multifunctional Hybrid Materials

DTIC Science & Technology

2016-01-01

properties, but also the synergistic interactions of reactive chemical and simulated solar UV environments with the hybrid film which leads to...applications possible including microelectronic interlayer dielectrics, antireflective coatings for solar cells , optical waveguides, size-selective...membranes, biosensors, micro-fluidic structures, and membranes in fuel cells . A critical aspect for all of these applications is that the hybrids

Effect of Grain Boundary Misorientation on Electromigration in Lead-Free Solder Joints

NASA Astrophysics Data System (ADS)

Tasooji, Amaneh; Lara, Leticia; Lee, Kyuoh

2014-12-01

Reduction in microelectronic interconnect size gives rise to solder bumps consisting of few grains, approaching a single- or bicrystal grain morphology in C4 bumps. Single grain anisotropy, individual grain orientation, presence of easy diffusion paths along grain boundaries, and the increased current density in these small solder bumps aggravate electromigration. This reduces the reliability of the entire microelectronic system. This paper focuses on electromigration behavior in Pb-free solder, specifically the Sn-0.7 wt.%Cu alloy. We discuss the effects of texture, grain orientation, and grain boundary misorientation angle on electromigration (EM) and intermetallic compound formation in EM-tested C4 bumps. The detailed electron backscatter diffraction (EBSD) analysis used in this study reveals the greater influence of grain boundary misorientation on solder bump electromigration compared with the effect associated with individual grain orientation.

Analysis of space radiation data of semiconductor memories

NASA Technical Reports Server (NTRS)

Stassinopoulos, E. G.; Brucker, G. J.; Stauffer, C. A.

1996-01-01

This article presents an analysis of radiation effects for several select device types and technologies aboard the Combined Release and Radiation Effects Satellite (CRRES) satellite. These space-flight measurements covered a period of about 14 months of mission lifetime. Single Event Upset (SEU) data of the investigated devices from the Microelectronics Package (MEP) were processed and analyzed. Valid upset measurements were determined by correcting for invalid readings, hard failures, missing data tapes (thus voids in data), and periods over which devices were disabled from interrogation. The basic resolution time of the measurement system was confirmed to be 2 s. Lessons learned, important findings, and recommendations are presented.

A high density two-dimensional electron gas in an oxide heterostructure on Si (001)

NASA Astrophysics Data System (ADS)

Jin, E. N.; Kornblum, L.; Kumah, D. P.; Zou, K.; Broadbridge, C. C.; Ngai, J. H.; Ahn, C. H.; Walker, F. J.

2014-11-01

We present the growth and characterization of layered heterostructures comprised of LaTiO3 and SrTiO3 epitaxially grown on Si (001). Magnetotransport measurements show that the sheet carrier densities of the heterostructures scale with the number of LaTiO3/SrTiO3 interfaces, consistent with the presence of an interfacial 2-dimensional electron gas (2DEG) at each interface. Sheet carrier densities of 8.9 × 1014 cm-2 per interface are observed. Integration of such high density oxide 2DEGs on silicon provides a bridge between the exceptional properties and functionalities of oxide 2DEGs and microelectronic technologies.

Documentation of the seawater intrusion (SWI2) package for MODFLOW

USGS Publications Warehouse

Bakker, Mark; Schaars, Frans; Hughes, Joseph D.; Langevin, Christian D.; Dausman, Alyssa M.

2013-01-01

The SWI2 Package is the latest release of the Seawater Intrusion (SWI) Package for MODFLOW. The SWI2 Package allows three-dimensional vertically integrated variable-density groundwater flow and seawater intrusion in coastal multiaquifer systems to be simulated using MODFLOW-2005. Vertically integrated variable-density groundwater flow is based on the Dupuit approximation in which an aquifer is vertically discretized into zones of differing densities, separated from each other by defined surfaces representing interfaces or density isosurfaces. The numerical approach used in the SWI2 Package does not account for diffusion and dispersion and should not be used where these processes are important. The resulting differential equations are equivalent in form to the groundwater flow equation for uniform-density flow. The approach implemented in the SWI2 Package allows density effects to be incorporated into MODFLOW-2005 through the addition of pseudo-source terms to the groundwater flow equation without the need to solve a separate advective-dispersive transport equation. Vertical and horizontal movement of defined density surfaces is calculated separately using a combination of fluxes calculated through solution of the groundwater flow equation and a simple tip and toe tracking algorithm. Use of the SWI2 Package in MODFLOW-2005 only requires the addition of a single additional input file and modification of boundary heads to freshwater heads referenced to the top of the aquifer. Fluid density within model layers can be represented using zones of constant density (stratified flow) or continuously varying density (piecewise linear in the vertical direction) in the SWI2 Package. The main advantage of using the SWI2 Package instead of variable-density groundwater flow and dispersive solute transport codes, such as SEAWAT and SUTRA, is that fewer model cells are required for simulations using the SWI2 Package because every aquifer can be represented by a single layer of cells. This reduction in number of required model cells and the elimination of the need to solve the advective-dispersive transport equation results in substantial model run-time savings, which can be large for regional aquifers. The accuracy and use of the SWI2 Package is demonstrated through comparison with existing exact solutions and numerical solutions with SEAWAT. Results for an unconfined aquifer are also presented to demonstrate application of the SWI2 Package to a large-scale regional problem.

Apparatus for assembly of microelectronic devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okandan, Murat; Nielson, Gregory N.; Cruz-Campa, Jose Luis

An apparatus including a carrier substrate configured to move a microelectronic device. The apparatus further includes a rotatable body configured to receive the microelectronic device. Additionally, the apparatus includes a second substrate configured to receive the microelectronic device from the rotatable body.

Wide area detection system: Conceptual design study. [using television and microelectronic technology

NASA Technical Reports Server (NTRS)

Hilbert, E. E.; Carl, C.; Goss, W.; Hansen, G. R.; Olsasky, M. J.; Johnston, A. R.

1978-01-01

An integrated sensor for traffic surveillance on mainline sections of urban freeways is described. Applicable imaging and processor technology is surveyed and the functional requirements for the sensors and the conceptual design of the breadboard sensors are given. Parameters measured by the sensors include lane density, speed, and volume. The freeway image is also used for incident diagnosis.

NASA Electronic Parts and Packaging (NEPP) Program - Update

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Sampson, Michael J.

2010-01-01

This slide presentation reviews the goals and mission of the NASA Electronic Parts and Packaging (NEPP) Program. The NEPP mission is to provide guidance to NASA for the selection and application of microelectronics technologies, to improve understanding of the risks related to the use of these technologies in the space environment and to ensure that appropriate research is performed to meet NASA mission assurance needs. The program has been supporting NASA for over 20 years. The focus is on the reliability aspects of electronic devices. In this work the program also supports the electronics industry. There are several areas that the program is involved in: Memories, systems on a chip (SOCs), data conversion devices, power MOSFETS, power converters, scaled CMOS, capacitors, linear devices, fiber optics, and other electronics such as sensors, cryogenic and SiGe that are used in space systems. Each of these area are reviewed with the work that is being done in reliability and effects of radiation on these technologies.

Reliability of High I/O High Density CCGA Interconnect Electronic Packages under Extreme Thermal Environment

NASA Technical Reports Server (NTRS)

Ramesham, Rajeshuni

2012-01-01

This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non-destructive inspection tools were used to assess the reliability of high density CCGA packages for deep space extreme temperature missions. Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performances, compatibility with standard surface-mount packaging assembly processes, and so on. CCGA packages are used in space applications such as in logic and microprocessor functions, telecommunications, payload electronics, and flight avionics. As these packages tend to have less solder joint strain relief than leaded packages or more strain relief over lead-less chip carrier packages, the reliability of CCGA packages is very important for short-term and long-term deep space missions. We have employed high density CCGA 1152 and 1272 daisy chained electronic packages in this preliminary reliability study. Each package is divided into several daisy-chained sections. The physical dimensions of CCGA1152 package is 35 mm x 35 mm with a 34 x 34 array of columns with a 1 mm pitch. The dimension of the CCGA1272 package is 37.5 mm x 37.5 mm with a 36 x 36 array with a 1 mm pitch. The columns are made up of 80% Pb/20%Sn material. CCGA interconnect electronic package printed wiring polyimide boards have been assembled and inspected using non-destructive x-ray imaging techniques. The assembled CCGA boards were subjected to extreme temperature thermal atmospheric cycling to assess their reliability for future deep space missions. The resistance of daisy-chained interconnect sections were monitored continuously during thermal cycling. This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non-destructive inspection tools were used to assess the reliability of high density CCGA packages for deep space extreme temperature missions. Keywords: Extreme temperatures, High density CCGA qualification, CCGA reliability, solder joint failures, optical inspection, and x-ray inspection.

Effect of packaging materials on shelf life and quality of banana cultivars (Musa spp.).

PubMed

Hailu, M; Seyoum Workneh, T; Belew, D

2014-11-01

This study was carried out to evaluate the effect of packaging materials on the shelf life of three banana cultivars. Four packaging materials, namely, perforated low density polyethylene bag, perforated high density polyethylene bag, dried banana leaf, teff straw and no packaging materials (control) were used with three banana cultivars, locally known as, Poyo, Giant Cavendish and Williams I. The experiment was carried out in Randomized Complete Block Design in a factorial combination with three replications. Physical parameters including weight loss, peel colour, peel thickness, pulp thickness, pulp to peel ratio, pulp firmness, pulp dry matter, decay, loss percent of marketability were assessed every 3 days. Banana remained marketable for 36 days in the high density polyethylene and low density polyethylene bags, and for 18 days in banana leaf and teff straw packaging treatments. Unpackaged fruits remained marketable for 15 days only. Fruits that were not packaged lost their weight by 24.0 % whereas fruits packaged in banana leaf and teff straw became unmarketable with final weight loss of 19.8 % and 20.9 %, respectively. Packaged fruits remained well until 36th days of storage with final weight loss of only 8.2 % and 9.20 %, respectively. Starting from green mature stage, the colour of the banana peel changed to yellow and this process was found to be fast for unpackaged fruits. Packaging maintained the peel and the pulp thickness, firmness, dry matter and pulp to peel ratio was kept lower. Decay loss for unpackaged banana fruits was16 % at the end of date 15, whereas the decay loss of fruits packaged using high density and low density polyethylene bags were 43.0 % and 41.2 %, respectively at the end of the 36th day of the experiment. It can, thus, be concluded that packaging of banana fruits in high density and low density polyethylene bags resulted in longer shelf life and improved quality of the produce followed by packaging in dried banana leaf and teff straw.

Vacuum mechatronics

NASA Technical Reports Server (NTRS)

Hackwood, Susan; Belinski, Steven E.; Beni, Gerardo

1989-01-01

The discipline of vacuum mechatronics is defined as the design and development of vacuum-compatible computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. The importance of vacuum mechatronics is growing with an increased application of vacuum in space studies and in manufacturing for material processing, medicine, microelectronics, emission studies, lyophylisation, freeze drying and packaging. The quickly developing field of vacuum mechatronics will also be the driving force for the realization of an advanced era of totally enclosed clean manufacturing cells. High technology manufacturing has increasingly demanding requirements for precision manipulation, in situ process monitoring and contamination-free environments. To remove the contamination problems associated with human workers, the tendency in many manufacturing processes is to move towards total automation. This will become a requirement in the near future for e.g., microelectronics manufacturing. Automation in ultra-clean manufacturing environments is evolving into the concept of self-contained and fully enclosed manufacturing. A Self Contained Automated Robotic Factory (SCARF) is being developed as a flexible research facility for totally enclosed manufacturing. The construction and successful operation of a SCARF will provide a novel, flexible, self-contained, clean, vacuum manufacturing environment. SCARF also requires very high reliability and intelligent control. The trends in vacuum mechatronics and some of the key research issues are reviewed.

Method of using sacrificial materials for fabricating internal cavities in laminated dielectric structures

DOEpatents

Peterson, Kenneth A [Albuquerque, NM

2009-02-24

A method of using sacrificial materials for fabricating internal cavities and channels in laminated dielectric structures, which can be used as dielectric substrates and package mounts for microelectronic and microfluidic devices. A sacrificial mandrel is placed in-between two or more sheets of a deformable dielectric material (e.g., unfired LTCC glass/ceramic dielectric), wherein the sacrificial mandrel is not inserted into a cutout made in any of the sheets. The stack of sheets is laminated together, which deforms the sheet or sheets around the sacrificial mandrel. After lamination, the mandrel is removed, (e.g., during LTCC burnout), thereby creating a hollow internal cavity in the monolithic ceramic structure.

Maskless wafer-level microfabrication of optical penetrating neural arrays out of soda-lime glass: Utah Optrode Array.

PubMed

Boutte, Ronald W; Blair, Steve

2016-12-01

Borrowing from the wafer-level fabrication techniques of the Utah Electrode Array, an optical array capable of delivering light for neural optogenetic studies is presented in this paper: the Utah Optrode Array. Utah Optrode Arrays are micromachined out of sheet soda-lime-silica glass using standard backend processes of the semiconductor and microelectronics packaging industries such as precision diamond grinding and wet etching. 9 × 9 arrays with 1100μ m × 100μ m optrodes and a 500μ m back-plane are repeatably reproduced on 2i n wafers 169 arrays at a time. This paper describes the steps and some of the common errors of optrode fabrication.

AE (Acoustic Emission) for Flip-Chip CGA/FCBGA Defect Detection

NASA Technical Reports Server (NTRS)

Ghaffarian, Reza

2014-01-01

C-mode scanning acoustic microscopy (C-SAM) is a nondestructive inspection technique that uses ultrasound to show the internal feature of a specimen. A very high or ultra-high-frequency ultrasound passes through a specimen to produce a visible acoustic microimage (AMI) of its inner features. As ultrasound travels into a specimen, the wave is absorbed, scattered or reflected. The response is highly sensitive to the elastic properties of the materials and is especially sensitive to air gaps. This specific characteristic makes AMI the preferred method for finding "air gaps" such as delamination, cracks, voids, and porosity. C-SAM analysis, which is a type of AMI, was widely used in the past for evaluation of plastic microelectronic circuits, especially for detecting delamination of direct die bonding. With the introduction of the flip-chip die attachment in a package; its use has been expanded to nondestructive characterization of the flip-chip solder bumps and underfill. Figure 1.1 compares visual and C-SAM inspection approaches for defect detection, especially for solder joint interconnections and hidden defects. C-SAM is specifically useful for package features like internal cracks and delamination. C-SAM not only allows for the visualization of the interior features, it has the ability to produce images on layer-by-layer basis. Visual inspection; however, is only superior to C-SAM for the exposed features including solder dewetting, microcracks, and contamination. Ideally, a combination of various inspection techniques - visual, optical and SEM microscopy, C-SAM, and X-ray - need to be performed in order to assure quality at part, package, and system levels. This reports presents evaluations performed on various advanced packages/assemblies, especially the flip-chip die version of ball grid array/column grid array (BGA/CGA) using C-SAM equipment. Both external and internal equipment was used for evaluation. The outside facility provided images of the key features that could be detected using the most advanced C-SAM equipment with a skilled operator. Investigation continued using in-house equipment with its limitations. For comparison, representative X-rays of the assemblies were also gathered to show key defect detection features of these non-destructive techniques. Key images gathered and compared are: Compared the images of 2D X-ray and C-SAM for a plastic LGA assembly showing features that could be detected by either NDE technique. For this specific case, X-ray was a clear winner. Evaluated flip-chip CGA and FCBGA assemblies with and without heat sink by C-SAM. Only the FCCGA package that had no heat sink could be fully analyzed for underfill and bump quality. Cross-sectional microscopy did not revealed peripheral delamination features detected by C-SAM. Analyzed a number of fine pitch PBGA assemblies by C-SAM. Even though the internal features of the package assemblies could be detected, C-SAM was unable to detect solder joint failure at either the package or board level. Twenty times touch ups by solder iron with 700degF tip temperature, each with about 5 second duration, did not induce defects to be detected by C-SAM images. Other techniques need to be considered to induce known defects for characterization. Given NASA's emphasis on the use of microelectronic packages and assemblies and quality assurance on workmanship defect detection, understanding key features of various inspection systems that detect defects in the early stages of package and assembly is critical to developing approaches that will minimize future failures. Additional specific, tailored non-destructive inspection approaches could enable low-risk insertion of these advanced electronic packages having hidden and fine features.

Low temperature wafer-level bonding for hermetic packaging of 3D microsystems

NASA Astrophysics Data System (ADS)

Tan, C. S.; Fan, J.; Lim, D. F.; Chong, G. Y.; Li, K. H.

2011-07-01

Metallic copper-copper (Cu-Cu) thermo-compression bonding, oxide-oxide (SiO2-SiO2) fusion bonding and silicon-silicon (Si-Si) direct bonding are investigated for potential application as hermetic seal in 3D microsystem packaging. Cavities are etched to a volume of 1.4 × 10-3 cm3 in accordance with the MIL-STD-883E standard prescribed for microelectronics packaging. In the case of metal bonding, a clean Cu layer with a thickness of 300 nm and a Ti barrier layer with an underlying thickness of 50 nm are used. The wafer pair is bonded at 300 °C under the application of a bonding force of 5500 N for 1 h. On the other hand, Si-Si bonding and SiO2-SiO2 bonding are initiated at room ambient after surface activation, followed by annealing in inert ambient at 300 °C for 1 h. The bonded cavities are stored in a helium bomb chamber and the leak rate is measured with a mass spectrometer. An excellent helium leak rate below 5 × 10-9 atm cm3 s-1 is detected for all cases and this is at least ten times better than the reject limit.

Reliability of high I/O high density CCGA interconnect electronic packages under extreme thermal environments

NASA Astrophysics Data System (ADS)

Ramesham, Rajeshuni

2012-03-01

Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performances, compatibility with standard surfacemount packaging assembly processes, and so on. CCGA packages are used in space applications such as in logic and microprocessor functions, telecommunications, payload electronics, and flight avionics. As these packages tend to have less solder joint strain relief than leaded packages or more strain relief over lead-less chip carrier packages, the reliability of CCGA packages is very important for short-term and long-term deep space missions. We have employed high density CCGA 1152 and 1272 daisy chained electronic packages in this preliminary reliability study. Each package is divided into several daisy-chained sections. The physical dimensions of CCGA1152 package is 35 mm x 35 mm with a 34 x 34 array of columns with a 1 mm pitch. The dimension of the CCGA1272 package is 37.5 mm x 37.5 mm with a 36 x 36 array with a 1 mm pitch. The columns are made up of 80% Pb/20%Sn material. CCGA interconnect electronic package printed wiring polyimide boards have been assembled and inspected using non-destructive x-ray imaging techniques. The assembled CCGA boards were subjected to extreme temperature thermal atmospheric cycling to assess their reliability for future deep space missions. The resistance of daisy-chained interconnect sections were monitored continuously during thermal cycling. This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non-destructive inspection tools were used to assess the reliability of high density CCGA packages for deep space extreme temperature missions.

Comparative Reliability Studies and Analysis of Au, Pd-Coated Cu and Pd-Doped Cu Wire in Microelectronics Packaging

PubMed Central

Chong Leong, Gan; Uda, Hashim

2013-01-01

This paper compares and discusses the wearout reliability and analysis of Gold (Au), Palladium (Pd) coated Cu and Pd-doped Cu wires used in fineline Ball Grid Array (BGA) package. Intermetallic compound (IMC) thickness measurement has been carried out to estimate the coefficient of diffusion (Do) under various aging conditions of different bonding wires. Wire pull and ball bond shear strengths have been analyzed and we found smaller variation in Pd-doped Cu wire compared to Au and Pd-doped Cu wire. Au bonds were identified to have faster IMC formation, compared to slower IMC growth of Cu. The obtained weibull slope, β of three bonding wires are greater than 1.0 and belong to wearout reliability data point. Pd-doped Cu wire exhibits larger time-to-failure and cycles-to-failure in both wearout reliability tests in Highly Accelerated Temperature and Humidity (HAST) and Temperature Cycling (TC) tests. This proves Pd-doped Cu wire has a greater potential and higher reliability margin compared to Au and Pd-coated Cu wires. PMID:24244344

A Model of BGA Thermal Fatigue Life Prediction Considering Load Sequence Effects

PubMed Central

Hu, Weiwei; Li, Yaqiu; Sun, Yufeng; Mosleh, Ali

2016-01-01

Accurate testing history data is necessary for all fatigue life prediction approaches, but such data is always deficient especially for the microelectronic devices. Additionally, the sequence of the individual load cycle plays an important role in physical fatigue damage. However, most of the existing models based on the linear damage accumulation rule ignore the sequence effects. This paper proposes a thermal fatigue life prediction model for ball grid array (BGA) packages to take into consideration the load sequence effects. For the purpose of improving the availability and accessibility of testing data, a new failure criterion is discussed and verified by simulation and experimentation. The consequences for the fatigue underlying sequence load conditions are shown. PMID:28773980

Goals, achievements of microelectronics program

NASA Astrophysics Data System (ADS)

Schronk, L.

1985-05-01

Besides reviewing the objectives of the government's microelectronics program, the Microelectronics Enterprise, the production of metal oxide semiconductors and bipolar integrated-circuit chips, specific research and development results to date, and the plans for future activity are discussed. Marketing and domestic demand are discussed.

The microstructure matters: breaking down the barriers with single crystalline silicon as negative electrode in Li-ion batteries

PubMed Central

Sternad, M.; Forster, M.; Wilkening, M.

2016-01-01

Silicon-based microelectronics forms a major foundation of our modern society. Small lithium-ion batteries act as the key enablers of its success and have revolutionised portable electronics used in our all everyday’s life. While large-scale LIBs are expected to help establish electric vehicles, on the other end of device size chip-integrated Si-based μ-batteries may revolutionise microelectronics once more. In general, Si is regarded as one of the white hopes since it offers energy densities being ten times higher than conventional anode materials. The use of monocrystalline, wafer-grade Si, however, requires several hurdles to be overcome since it its volume largely expands during lithiation. Here, we will show how 3D patterned Si wafers, prepared by the sophisticated techniques from semiconductor industry, are to be electrochemically activated to overcome these limitations and to leverage their full potential being reflected in stable charge capacities (>1000 mAhg–1) and high Coulomb efficiencies (98.8%). PMID:27531589

Recent patents on Cu/low-k dielectrics interconnects in integrated circuits.

PubMed

Jiang, Qing; Zhu, Yong F; Zhao, Ming

2007-01-01

In past decades, the development of microelectronics has moved along with constant speed of scaling to maximize transistor density as driven by the need for electrical and functional performance. For further development, the propagation velocity of electromagnetic waves becomes increasingly important due to their unyielding constraints on interconnect delay. To minimize it, it was forced to the introduction of the Cu/low-k dielectric interconnects to very large scale integrated circuits (VLSI) where k denotes the dielectric constant. In addition, reliable barrier structures, which are the thinnest part among the device parts to maximize space availability for the actual Cu IWs, are required to prevent penetration of different materials. In light of the above statements, this review will focus recent patents and some studies on Cu interconnects including Cu interconnect wires, low-k dielectrics and related barrier materials as well manufacturing techniques in VLSI, which are one of the most essential concerns in microelectronic industry and decides the further development of VLSI. In addition, possible future development in this field is considered.

The Legacy of the Microelectronics Education Programme.

ERIC Educational Resources Information Center

Thorne, Michael

1987-01-01

Describes the Microelectronics Education Programme (MEP), a plan developed to help British secondary school students learn about microcomputers and the role of technology in society, and its successor, the Microelectronics Support Unit (MESU). Highlights include curriculum development, teacher training, computer assisted instruction and the…

Educational Implications of Microelectronics and Microprocessors.

ERIC Educational Resources Information Center

Harris, N. D. C., Ed.

This conference report explores microelectronic technology, its effect on educational methods and objectives, and its implications for educator responsibilities. Two main areas were considered: the significance of the likely impact of the large scale introduction of microprocessors and microelectronics on commercial and industrial processes, the…

Scaled CMOS Technology Reliability Users Guide

NASA Technical Reports Server (NTRS)

White, Mark

2010-01-01

The desire to assess the reliability of emerging scaled microelectronics technologies through faster reliability trials and more accurate acceleration models is the precursor for further research and experimentation in this relevant field. The effect of semiconductor scaling on microelectronics product reliability is an important aspect to the high reliability application user. From the perspective of a customer or user, who in many cases must deal with very limited, if any, manufacturer's reliability data to assess the product for a highly-reliable application, product-level testing is critical in the characterization and reliability assessment of advanced nanometer semiconductor scaling effects on microelectronics reliability. A methodology on how to accomplish this and techniques for deriving the expected product-level reliability on commercial memory products are provided.Competing mechanism theory and the multiple failure mechanism model are applied to the experimental results of scaled SDRAM products. Accelerated stress testing at multiple conditions is applied at the product level of several scaled memory products to assess the performance degradation and product reliability. Acceleration models are derived for each case. For several scaled SDRAM products, retention time degradation is studied and two distinct soft error populations are observed with each technology generation: early breakdown, characterized by randomly distributed weak bits with Weibull slope (beta)=1, and a main population breakdown with an increasing failure rate. Retention time soft error rates are calculated and a multiple failure mechanism acceleration model with parameters is derived for each technology. Defect densities are calculated and reflect a decreasing trend in the percentage of random defective bits for each successive product generation. A normalized soft error failure rate of the memory data retention time in FIT/Gb and FIT/cm2 for several scaled SDRAM generations is presented revealing a power relationship. General models describing the soft error rates across scaled product generations are presented. The analysis methodology may be applied to other scaled microelectronic products and their key parameters.

REVIEW ARTICLE: How will physics be involved in silicon microelectronics

NASA Astrophysics Data System (ADS)

Kamarinos, Georges; Felix, Pierre

1996-03-01

By the year 2000 electronics will probably be the basis of the largest industry in the world. Silicon microelectronics will continue to keep a dominant place covering 99% of the `semiconductor market'. The aim of this review article is to indicate for the next decade the domains in which research work in `physics' is needed for a technological advance towards increasing speed, complexity and density of silicon ultra large scale integration (ULSI) integrated circuits (ICs). By `physics' we mean here not only condensed matter physics but also the basic physical chemistry and thermodynamics. The review begins with a brief and general introduction in which we elucidate the current state of the art and the trends in silicon microelectronics. Afterwards we examine the involvement of physics in silicon microelectronics in the two main sections. The first section concerns the processes of fabrication of ICs: lithography, oxidation, diffusion, chemical and physical vapour deposition, rapid thermal processing, etching, interconnections, ultra-clean processing and microcontamination. The second section concerns the electrical operation of the ULSI devices. It defines the integration scales and points out the importance of the intermediate scale of integration which is the scale of the next generation of ICs. The emergence of cryomicroelectronics is also reviewed and an extended paragraph is dedicated to the problem of reliability and ageing of devices and ICs: hot carrier degradation, interdevice coupling and noise are considered. It is shown, during our analysis, that the next generation of silicon ICs needs mainly: (i) `scientific' fabrication and (ii) microscopic modelling and simulation of the electrical characteristics of the scaled down devices. To attain the above objectives a return to the `first principles' of physics as well as a recourse to nonlinear and non-equilibrium thermodynamics are mandatory. In the references we list numerous review papers and references of specialized colloquia proceedings so that a more detailed survey of the subject is possible for the reader.

A Survey of Current Trends in Master's Programs in Microelectronics

ERIC Educational Resources Information Center

Bozanic, Mladen; Sinha, Saurabh

2018-01-01

Contribution: This paper brings forward a paradigm shift in microelectronic and nanoelectronic engineering education. Background: An increasing number of universities are offering graduate-level electrical engineering degree programs with multi-disciplinary Master's-level specialization in microelectronics or nanoelectronics. The paradigm shift…

Microelectronics in Education

ERIC Educational Resources Information Center

Orton, Richard J. J.

2011-01-01

The history and meaning of the term "microelectronics" is reviewed, followed by a discussion of the key inventions of the Intel microprocessor in 1971 and the Texas Instruments electronic pocket calculator in 1975. The six characteristic features of microelectronic components are then defined. The UK prime minister Jim Callaghan's…

The Co-60 gamma-ray irradiation effects on the Al/HfSiO4/p-Si/Al MOS capacitors

NASA Astrophysics Data System (ADS)

Lok, R.; Kaya, S.; Karacali, H.; Yilmaz, E.

2017-12-01

In this work, the initial interface trap density (Nit) to examine device compability for microelectronics and then the Co-60 gamma irradiation responses of Al/HfSiO4/p-Si/Al (MOS) capacitors were investigated in various dose ranges up to 70 Gy. Pre-irradiation response of the devices was evaluated from high frequency (HF) and low frequency (LF) capacitance method and the Nit was calculated as 9.91 × 1011 cm-2 which shows that the HfSiO4/p-Si interface quality is convenient for microelectronics applications. The irradiation responses of the devices were carried out from flat-band and mid-gap voltage shifts obtained from stretch of capacitance characteristics prior to and after irradiation. The results show that the flat band voltages very slightly shifted to positive voltage values demonstrating the enhancement of negative charge trapping in device structure. The sensitivity of the Al/HfSiO4/p-Si/Al MOS capacitors was found to be 4.41 mV/Gy for 300 nm-thick HfSiO4 gate dielectrics. This value approximately 6.5 times smaller compared to the same thickness conventional SiO2 based MOS devices. Therefore, HfSiO4 exhibits crucial irradiation tolerance in gamma irradiation environment. Consequently, HfSiO4 dielectrics may have significant usage for microelectronic technology as a radiation hard material where radiation field exists such as in space applications.

Microelectronics and Special Education. CET/MEP Information Sheet.

ERIC Educational Resources Information Center

Council for Educational Technology, London (England).

Used as an additional aid by the teacher, microelectronics can assist mentally and physically handicapped children to meet educational objectives that have been specifically agreed upon for the individual child. Microelectronics can help deaf children develop speech production, communication skills, and grammar and sentence construction;…

Microelectronics and Music Education.

ERIC Educational Resources Information Center

Hofstetter, Fred T.

1979-01-01

This look at the impact of microelectronics on computer-assisted instruction (CAI) in music notes trends toward new applications and lower costs. Included are: a rationale for CAI in music, a list of sample programs, comparison of five microelectronic music systems, PLATO cost projections, and sources of further information. (SJL)

Microelectronics in the Curriculum--The Science Teacher's Contribution.

ERIC Educational Resources Information Center

Association for Science Education, Cambridge (England).

Rapid advances in microelectronics over the past few years have generally been beneficial, but they have also created some problems, and questions must be asked about the philosophy for including aspects of the new technology in the school curriculum. This statement, prepared by the Microelectronics and Science Education Subcommittee of the…

Study on influences of TiN capping layer on time-dependent dielectric breakdown characteristic of ultra-thin EOT high-k metal gate NMOSFET with kMC TDDB simulations

NASA Astrophysics Data System (ADS)

Xu, Hao; Yang, Hong; Luo, Wei-Chun; Xu, Ye-Feng; Wang, Yan-Rong; Tang, Bo; Wang, Wen-Wu; Qi, Lu-Wei; Li, Jun-Feng; Yan, Jiang; Zhu, Hui-Long; Zhao, Chao; Chen, Da-Peng; Ye, Tian-Chun

2016-08-01

The thickness effect of the TiN capping layer on the time dependent dielectric breakdown (TDDB) characteristic of ultra-thin EOT high-k metal gate NMOSFET is investigated in this paper. Based on experimental results, it is found that the device with a thicker TiN layer has a more promising reliability characteristic than that with a thinner TiN layer. From the charge pumping measurement and secondary ion mass spectroscopy (SIMS) analysis, it is indicated that the sample with the thicker TiN layer introduces more Cl passivation at the IL/Si interface and exhibits a lower interface trap density. In addition, the influences of interface and bulk trap density ratio N it/N ot are studied by TDDB simulations through combining percolation theory and the kinetic Monte Carlo (kMC) method. The lifetime reduction and Weibull slope lowering are explained by interface trap effects for TiN capping layers with different thicknesses. Project supported by the National High Technology Research and Development Program of China (Grant No. SS2015AA010601), the National Natural Science Foundation of China (Grant Nos. 61176091 and 61306129), and the Opening Project of Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of MicroElectronics of Chinese Academy of Sciences.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salama, A.; Mikhail, M.

Comprehensive software packages have been developed at the Western Research Centre as tools to help coal preparation engineers analyze, evaluate, and control coal cleaning processes. The COal Preparation Software package (COPS) performs three functions: (1) data handling and manipulation, (2) data analysis, including the generation of washability data, performance evaluation and prediction, density and size modeling, evaluation of density and size partition characteristics and attrition curves, and (3) generation of graphics output. The Separation ChARacteristics Estimation software packages (SCARE) are developed to balance raw density or size separation data. The cases of density and size separation data are considered. Themore » generated balanced data can take the balanced or normalized forms. The scaled form is desirable for direct determination of the partition functions (curves). The raw and generated separation data are displayed in tabular and/or graphical forms. The computer softwares described in this paper are valuable tools for coal preparation plant engineers and operators for evaluating process performance, adjusting plant parameters, and balancing raw density or size separation data. These packages have been applied very successfully in many projects carried out by WRC for the Canadian coal preparation industry. The software packages are designed to run on a personal computer (PC).« less

Effects of Graphene Monolayer Coating on the Optical Performance of Remote Phosphors

NASA Astrophysics Data System (ADS)

Yazdan Mehr, M.; Volgbert, S.; van Driel, W. D.; Zhang, G. Q.

2017-10-01

A graphene monolayer has been successfully coated on one side of a bisphenol-A-polycarbonate (BPA-PC) plate, used as a substrate for remote phosphor applications in light-emitting diode (LED)-based products. Using a photoresist transferring method, graphene sheet has been coated on BPA-PC plates. The results show that this graphene monolayer significantly improves the lifetime and performance of LEDs mainly by protecting them against external degradation factors such as moisture and oxygen. Also, LED-based products composed of graphene-coated BPA-PC plates exhibit longer stability with comparatively less loss of luminous efficiency. This method has great potential to significantly improve the reliability of not only LED-based products but also many other microelectronics packaging and components, in which moisture and oxygen are the key causes of failures.

Deep Space 1: Testing New Technologies for Future Small Bodies Missions

NASA Technical Reports Server (NTRS)

Rayman, Marc D.

2001-01-01

Launched on October 24, 1998, Deep Space 1 (DS1) was the first mission of NASA's New Millennium Program, chartered to validate in space high-risk, new technologies important for future space science programs. The advanced technology payload that was tested on DS1 comprises solar electric propulsion, solar concentrator arrays, autonomous on-board navigation and other autonomous systems, several telecommunications and microelectronics devices, and two low-mass integrated science instrument packages. The mission met or exceeded all of its success criteria. The 12 technologies were rigorously exercised so that subsequent flight projects would not have to incur the cost and risk of being the fist users of these new capabilities. Examples of the benefits to future small body missions from DS1's technologies will be described.

Design, Fabrication, and Characterization of Carbon Nanotube Field Emission Devices for Advanced Applications

NASA Astrophysics Data System (ADS)

Radauscher, Erich Justin

Carbon nanotubes (CNTs) have recently emerged as promising candidates for electron field emission (FE) cathodes in integrated FE devices. These nanostructured carbon materials possess exceptional properties and their synthesis can be thoroughly controlled. Their integration into advanced electronic devices, including not only FE cathodes, but sensors, energy storage devices, and circuit components, has seen rapid growth in recent years. The results of the studies presented here demonstrate that the CNT field emitter is an excellent candidate for next generation vacuum microelectronics and related electron emission devices in several advanced applications. The work presented in this study addresses determining factors that currently confine the performance and application of CNT-FE devices. Characterization studies and improvements to the FE properties of CNTs, along with Micro-Electro-Mechanical Systems (MEMS) design and fabrication, were utilized in achieving these goals. Important performance limiting parameters, including emitter lifetime and failure from poor substrate adhesion, are examined. The compatibility and integration of CNT emitters with the governing MEMS substrate (i.e., polycrystalline silicon), and its impact on these performance limiting parameters, are reported. CNT growth mechanisms and kinetics were investigated and compared to silicon (100) to improve the design of CNT emitter integrated MEMS based electronic devices, specifically in vacuum microelectronic device (VMD) applications. Improved growth allowed for design and development of novel cold-cathode FE devices utilizing CNT field emitters. A chemical ionization (CI) source based on a CNT-FE electron source was developed and evaluated in a commercial desktop mass spectrometer for explosives trace detection. This work demonstrated the first reported use of a CNT-based ion source capable of collecting CI mass spectra. The CNT-FE source demonstrated low power requirements, pulsing capabilities, and average lifetimes of over 320 hours when operated in constant emission mode under elevated pressures, without sacrificing performance. Additionally, a novel packaged ion source for miniature mass spectrometer applications using CNT emitters, a MEMS based Nier-type geometry, and a Low Temperature Cofired Ceramic (LTCC) 3D scaffold with integrated ion optics were developed and characterized. While previous research has shown other devices capable of collecting ion currents on chip, this LTCC packaged MEMS micro-ion source demonstrated improvements in energy and angular dispersion as well as the ability to direct the ions out of the packaged source and towards a mass analyzer. Simulations and experimental design, fabrication, and characterization were used to make these improvements. Finally, novel CNT-FE devices were developed to investigate their potential to perform as active circuit elements in VMD circuits. Difficulty integrating devices at micron-scales has hindered the use of vacuum electronic devices in integrated circuits, despite the unique advantages they offer in select applications. Using a combination of particle trajectory simulation and experimental characterization, device performance in an integrated platform was investigated. Solutions to the difficulties in operating multiple devices in close proximity and enhancing electron transmission (i.e., reducing grid loss) are explored in detail. A systematic and iterative process was used to develop isolation structures that reduced crosstalk between neighboring devices from 15% on average, to nearly zero. Innovative geometries and a new operational mode reduced grid loss by nearly threefold, thereby improving transmission of the emitted cathode current to the anode from 25% in initial designs to 70% on average. These performance enhancements are important enablers for larger scale integration and for the realization of complex vacuum microelectronic circuits.

Microelectronics bioinstrumentation systems

NASA Technical Reports Server (NTRS)

Ko, W. H.

1977-01-01

Microelectronic bioinstrumentation systems to be employed in the Cardiovascular Deconditioning Program were developed. Implantable telemetry systems for long-term monitoring of animals on earth were designed to collect physiological data necessary for the understanding of the mechanisms of cardiovascular deconditioning. In-flight instrumentation systems, microelectronic instruments, and RF powering techniques for other life science experiments in the NASA program were studied.

Relevance of microelectronic education to industrial needs

NASA Technical Reports Server (NTRS)

Prince, J. L.; Lathrop, J. W.

1977-01-01

The relevance of microelectronic education to industrial needs was evaluated, and four categories were surveyed: (1) facts and rules; (2) skills; (3) personality; and (4) deductive-inductive reasoning. Examples of specific items in each category are given to illustrate their meaning and it was indicated as to which items in each category are strongly impacted by microelectronics courses and laboratories.

A molecular shift register based on electron transfer

NASA Technical Reports Server (NTRS)

Hopfield, J. J.; Onuchic, Josenelson; Beratan, David N.

1988-01-01

An electronic shift-register memory at the molecular level is described. The memory elements are based on a chain of electron-transfer molecules and the information is shifted by photoinduced electron-transfer reactions. This device integrates designed electronic molecules onto a very large scale integrated (silicon microelectronic) substrate, providing an example of a 'molecular electronic device' that could actually be made. The design requirements for such a device and possible synthetic strategies are discussed. Devices along these lines should have lower energy usage and enhanced storage density.

Spreading devices into a 2-D module layout

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koplow, Jeffrey P.; Gupta, Vipin P.; Nielson, Gregory N.

An apparatus, method, and system, the apparatus including a receiving member dimensioned to receive an array of microelectronic devices; and a linkage member coupled to the receiving member, the linkage member configured to move the receiving member in at least two dimensions so as to modify a spacing between the electronic devices within the array of microelectronic devices received by the receiving member. The method including coupling an array of microelectronic devices to an expansion assembly; and expanding the expansion assembly so as to expand the array of microelectronic devices in at least two directions within a single plane. Themore » system including a support member; an expansion assembly coupled to the support member, the expansion assembly having a plurality of receiving members configured to move in at least two dimensions within a single plane; and a plurality of microelectronic devices coupled to each of the plurality of receiving members.« less

Photoemission-based microelectronic devices

PubMed Central

Forati, Ebrahim; Dill, Tyler J.; Tao, Andrea R.; Sievenpiper, Dan

2016-01-01

The vast majority of modern microelectronic devices rely on carriers within semiconductors due to their integrability. Therefore, the performance of these devices is limited due to natural semiconductor properties such as band gap and electron velocity. Replacing the semiconductor channel in conventional microelectronic devices with a gas or vacuum channel may scale their speed, wavelength and power beyond what is available today. However, liberating electrons into gas/vacuum in a practical microelectronic device is quite challenging. It often requires heating, applying high voltages, or using lasers with short wavelengths or high powers. Here, we show that the interaction between an engineered resonant surface and a low-power infrared laser can cause enough photoemission via electron tunnelling to implement feasible microelectronic devices such as transistors, switches and modulators. The proposed photoemission-based devices benefit from the advantages of gas-plasma/vacuum electronic devices while preserving the integrability of semiconductor-based devices. PMID:27811946

Thermal Flow Sensors for Harsh Environments.

PubMed

Balakrishnan, Vivekananthan; Phan, Hoang-Phuong; Dinh, Toan; Dao, Dzung Viet; Nguyen, Nam-Trung

2017-09-08

Flow sensing in hostile environments is of increasing interest for applications in the automotive, aerospace, and chemical and resource industries. There are thermal and non-thermal approaches for high-temperature flow measurement. Compared to their non-thermal counterparts, thermal flow sensors have recently attracted a great deal of interest due to the ease of fabrication, lack of moving parts and higher sensitivity. In recent years, various thermal flow sensors have been developed to operate at temperatures above 500 °C. Microelectronic technologies such as silicon-on-insulator (SOI), and complementary metal-oxide semiconductor (CMOS) have been used to make thermal flow sensors. Thermal sensors with various heating and sensing materials such as metals, semiconductors, polymers and ceramics can be selected according to the targeted working temperature. The performance of these thermal flow sensors is evaluated based on parameters such as thermal response time, flow sensitivity. The data from thermal flow sensors reviewed in this paper indicate that the sensing principle is suitable for the operation under harsh environments. Finally, the paper discusses the packaging of the sensor, which is the most important aspect of any high-temperature sensing application. Other than the conventional wire-bonding, various novel packaging techniques have been developed for high-temperature application.

Thermal Flow Sensors for Harsh Environments

PubMed Central

Dinh, Toan; Dao, Dzung Viet

2017-01-01

Flow sensing in hostile environments is of increasing interest for applications in the automotive, aerospace, and chemical and resource industries. There are thermal and non-thermal approaches for high-temperature flow measurement. Compared to their non-thermal counterparts, thermal flow sensors have recently attracted a great deal of interest due to the ease of fabrication, lack of moving parts and higher sensitivity. In recent years, various thermal flow sensors have been developed to operate at temperatures above 500 °C. Microelectronic technologies such as silicon-on-insulator (SOI), and complementary metal-oxide semiconductor (CMOS) have been used to make thermal flow sensors. Thermal sensors with various heating and sensing materials such as metals, semiconductors, polymers and ceramics can be selected according to the targeted working temperature. The performance of these thermal flow sensors is evaluated based on parameters such as thermal response time, flow sensitivity. The data from thermal flow sensors reviewed in this paper indicate that the sensing principle is suitable for the operation under harsh environments. Finally, the paper discusses the packaging of the sensor, which is the most important aspect of any high-temperature sensing application. Other than the conventional wire-bonding, various novel packaging techniques have been developed for high-temperature application. PMID:28885595

IR DirectFET Extreme Environments Evaluation Final Report

NASA Technical Reports Server (NTRS)

Burmeister, Martin; Mottiwala, Amin

2008-01-01

In 2007, International Rectifier (IR) introduced a new version of its DirectFET metal oxide semiconductor field effect transistor (MOSFET) packaging. The new version (referred to as 'Version 2') enhances device moisture resistance, makes surface mount (SMT) assembly of these devices to printed wiring boards (PWBs) more repeatable, and subsequent assembly inspection simpler. In the present study, the National Aeronautics Space Administration (NASA) Jet Propulsion Laboratory (JPL), in collaboration with Stellar Microelectronics (Stellar), continued an evaluation of the DirectFET that they started together in 2006. The present study focused on comparing the two versions of the DirectFET and examining the suitability of the DirectFET devices for space applications. This study evaluated both versions of two DirectFET packaged devices that had both been shown in the 2006 study to have the best electrical and thermal properties: the IRF6635 and IRF6644. The present study evaluated (1) the relative electrical and thermal performance of both versions of each device, (2) the performance through high reliability testing, and (3) the performance of these devices in combination with a range of alternate solder alloys in the extreme thermal environments of deep space....

Packaging's Contribution for the Effectiveness of the Space Station's Food Service Operation

NASA Technical Reports Server (NTRS)

Rausch, B. A.

1985-01-01

Storage limitations will have a major effect on space station food service. For example: foods with low bulk density such as ice cream, bread, cake, standard type potato chips and other low density snacks, flaked cereals, etc., will exacerbate the problem of space limitations; package containers are inherently volume consuming and refuse creating; and the useful observation that the optimum package is no package at all leads to the tentative conclusion that the least amount of packaging per unit of food, consistent with storage, aesthetics, preservation, cleanliness, cost and disposal criteria, is the most practical food package for the space station. A series of trade offs may have to be made to arrive at the most appropriate package design for a particular type of food taking all the criteria into account. Some of these trade offs are: single serve vs. bulk; conventional oven vs. microwave oven; nonmetallic aseptically vs. non-aseptically packaged foods; and comparison of aseptic vs. nonaseptic food packages. The advantages and disadvantages are discussed.

Trusted Defense Microelectronics: Future Access and Capabilities Are Uncertain

DTIC Science & Technology

2015-10-28

Board Task Force on High Performance Microchip Supply and documentation and discussions with industry and DOD officials in September and October...the defense and microelectronics industry . DOD’s review of this report deemed some of this information as sensitive but unclassified. What GAO...increased specialization and industry consolidation. • Once dominated by domestic sources, the supply chain for microelectronics manufacturing is a global one

Microelectronics: The Nature of Work, Skills and Training. An Analysis of Case Studies from Developed and Developing Countries. Training Discussion Paper No. 51.

ERIC Educational Resources Information Center

Acero, Liliana

Microelectronic technologies have had an impact on the nature of work in industry for both white-collar and blue-collar workers. Evidence from sector- and enterprise-level studies shows changes in skills and job content for blue-collar workers involved with numerically controlled machine tools, robots, and other microelectronics applications.…

Steady-state low thermal resistance characterization apparatus: The bulk thermal tester

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burg, Brian R.; Kolly, Manuel; Blasakis, Nicolas

The reliability of microelectronic devices is largely dependent on electronic packaging, which includes heat removal. The appropriate packaging design therefore necessitates precise knowledge of the relevant material properties, including thermal resistance and thermal conductivity. Thin materials and high conductivity layers make their thermal characterization challenging. A steady state measurement technique is presented and evaluated with the purpose to characterize samples with a thermal resistance below 100 mm{sup 2} K/W. It is based on the heat flow meter bar approach made up by two copper blocks and relies exclusively on temperature measurements from thermocouples. The importance of thermocouple calibration is emphasizedmore » in order to obtain accurate temperature readings. An in depth error analysis, based on Gaussian error propagation, is carried out. An error sensitivity analysis highlights the importance of the precise knowledge of the thermal interface materials required for the measurements. Reference measurements on Mo samples reveal a measurement uncertainty in the range of 5% and most accurate measurements are obtained at high heat fluxes. Measurement techniques for homogeneous bulk samples, layered materials, and protruding cavity samples are discussed. Ultimately, a comprehensive overview of a steady state thermal characterization technique is provided, evaluating the accuracy of sample measurements with thermal resistances well below state of the art setups. Accurate characterization of materials used in heat removal applications, such as electronic packaging, will enable more efficient designs and ultimately contribute to energy savings.« less

Modeling biology with HDL languages: a first step toward a genetic design automation tool inspired from microelectronics.

PubMed

Gendrault, Yves; Madec, Morgan; Lallement, Christophe; Haiech, Jacques

2014-04-01

Nowadays, synthetic biology is a hot research topic. Each day, progresses are made to improve the complexity of artificial biological functions in order to tend to complex biodevices and biosystems. Up to now, these systems are handmade by bioengineers, which require strong technical skills and leads to nonreusable development. Besides, scientific fields that share the same design approach, such as microelectronics, have already overcome several issues and designers succeed in building extremely complex systems with many evolved functions. On the other hand, in systems engineering and more specifically in microelectronics, the development of the domain has been promoted by both the improvement of technological processes and electronic design automation tools. The work presented in this paper paves the way for the adaptation of microelectronics design tools to synthetic biology. Considering the similarities and differences between the synthetic biology and microelectronics, the milestones of this adaptation are described. The first one concerns the modeling of biological mechanisms. To do so, a new formalism is proposed, based on an extension of the generalized Kirchhoff laws to biology. This way, a description of all biological mechanisms can be made with languages widely used in microelectronics. Our approach is therefore successfully validated on specific examples drawn from the literature.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Ying; Li, Hong; Bridges, Denzel

We report that the continuing miniaturization of microelectronics is pushing advanced manufacturing into nanomanufacturing. Nanojoining is a bottom-up assembly technique that enables functional nanodevice fabrication with dissimilar nanoscopic building blocks and/or molecular components. Various conventional joining techniques have been modified and re-invented for joining nanomaterials. Our review surveys recent progress in nanojoining methods, as compared to conventional joining processes. Examples of nanojoining are given and classified by the dimensionality of the joining materials. At each classification, nanojoining is reviewed and discussed according to materials specialties, low dimensional processing features, energy input mechanisms and potential applications. The preparation of new intermetallicmore » materials by reactive nanoscale multilayer foils based on self-propagating high-temperature synthesis is highlighted. This review will provide insight into nanojoining fundamentals and innovative applications in power electronics packaging, plasmonic devices, nanosoldering for printable electronics, 3D printing and space manufacturing.« less

Theoretical and Experimental Beam Plasma Physics (TEBPP)

NASA Technical Reports Server (NTRS)

Roberts, W. T.

1985-01-01

The theoretical and experimental beam plasma physics (TEBPP) consists of a package of five instruments to measure electric and magnetic fields, plasma density and temperature, neutral density, photometric emissions, and energetic particle spectra during firings of the particle injector (SEPAC) electron beam. The package is deployed on a maneuverable boom (or RMS) and is used to measure beam characteristics and induced perturbations in the near field ( 10 m) and mid field (10 m to 100 m) along the electron beam. The TEBPP package will be designed to investigate induced oscillations and induced electromagnetic mode waves, neutral and ion density and temperature effects, and beam characteristics as a function of axial distance.

Theoretical and Experimental Beam Plasma Physics (TEBPP)

NASA Technical Reports Server (NTRS)

Roberts, B.

1986-01-01

The theoretical and experimental beam plasma physics (TEBPP) consists of a package of five instruments to measure electric and magnetic fields, plasma density and temperature, neutral density, photometric emissions, and energetic particle spectra during firings of the particle injector (SEPAC) electron beam. The package is developed on a maneuverable boom (or RMS) and is used to measure beam characteristics and induced perturbations field ( 10 m) and mid field ( 10 m to 100 m) along the electron beam. The TEBPP package will be designed to investigate induced oscillations and induced electromagnetic mode waves, neutral and ion density and temperature effects, and beam characteristics as a function of axial distance.

Delaying microbial proliferation in freshly peeled shallots by active packaging incorporating ethanol vapour-controlled release sachets and low storage temperature.

PubMed

Utto, Weerawate; Preutikul, Rittirong; Malila, Patcharee; Noomhorm, Athapol; Bronlund, John E

2018-03-01

This research was conducted to investigate effects of ethanol vapour released in active packaging and storage temperatures on the quality of freshly peeled shallots. The package tested was a solid polypropylene tray incorporating an ethanol vapour-controlled release sachet. The sachet was made of an aluminium foil film on one side and either low-density polyethylene or nylon/polyethylene on the other. Individual sachets contained silica gel adsorbent as the carrier pre-loaded with ethanol. One sachet was placed in each tray containing the peeled shallots and the tray was heat sealed with the low-density polyethylene film lid. Packages were stored at either 10 or 25 ℃ for 10 d. Trays containing only peeled shallots were designated as controls. High storage temperature stimulated quality changes in the shallots. Although ethanol vapour accumulated in the active package headspace, the extent to which ethanol concentrations increased within the shallots was not significantly different from that in the control packages. Microbial proliferation in terms of yeast and mould counts could be delayed through a combination of 10 ℃ and ethanol vapour released from the low-density polyethylene sachet. The ethanol vapour accumulated in the packages did not have a significant effect on mass loss, firmness, and colour changes in the peeled shallots, or on the concentrations of oxygen and carbon dioxide in the packages.

Current rectifying and resistive switching in high density BiFeO3 nanocapacitor arrays on Nb-SrTiO3 substrates

PubMed Central

Zhao, Lina; Lu, Zengxing; Zhang, Fengyuan; Tian, Guo; Song, Xiao; Li, Zhongwen; Huang, Kangrong; Zhang, Zhang; Qin, Minghui; SujuanWu; Lu, Xubing; Zeng, Min; Gao, Xingsen; Dai, Jiyan; Liu, Jun-Ming

2015-01-01

Ultrahigh density well-registered oxide nanocapacitors are very essential for large scale integrated microelectronic devices. We report the fabrication of well-ordered multiferroic BiFeO3 nanocapacitor arrays by a combination of pulsed laser deposition (PLD) method and anodic aluminum oxide (AAO) template method. The capacitor cells consist of BiFeO3/SrRuO3 (BFO/SRO) heterostructural nanodots on conductive Nb-doped SrTiO3 (Nb-STO) substrates with a lateral size of ~60 nm. These capacitors also show reversible polarization domain structures, and well-established piezoresponse hysteresis loops. Moreover, apparent current-rectification and resistive switching behaviors were identified in these nanocapacitor cells using conductive-AFM technique, which are attributed to the polarization modulated p-n junctions. These make it possible to utilize these nanocapacitors in high-density (>100 Gbit/inch2) nonvolatile memories and other oxide nanoelectronic devices. PMID:25853937

Integrated Avionics System (IAS), Integrating 3-D Technology On A Spacecraft Panel

NASA Technical Reports Server (NTRS)

Hunter, Don J.; Halpert, Gerald

1999-01-01

As spacecraft designs converge toward miniaturization, and with the volumetric and mass challenges placed on avionics, programs will continue to advance the "state of the art" in spacecraft system development with new challenges to reduce power, mass and volume. Traditionally, the trend is to focus on high-density 3-D packaging technologies. Industry has made significant progress in 3-D technologies, and other related internal and external interconnection schemes. Although new technologies have improved packaging densities, a system packaging architecture is required that not only reduces spacecraft volume and mass budgets, but increase integration efficiencies, provide modularity and flexibility to accommodate multiple missions while maintaining a low recurring cost. With these challenges in mind, a novel system packaging approach incorporates solutions that provide broader environmental applications, more flexible system interconnectivity, scalability, and simplified assembly test and integration schemes. The Integrated Avionics System (IAS) provides for a low-mass, modular distributed or centralized packaging architecture which combines ridged-flex technologies, high-density COTS hardware and a new 3-D mechanical packaging approach, Horizontal Mounted Cube (HMC). This paper will describe the fundamental elements of the IAS, HMC hardware design, system integration and environmental test results.

Advanced Packaging Materials and Techniques for High Power TR Module: Standard Flight vs. Advanced Packaging

NASA Technical Reports Server (NTRS)

Hoffman, James Patrick; Del Castillo, Linda; Miller, Jennifer; Jenabi, Masud; Hunter, Donald; Birur, Gajanana

2011-01-01

The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires advances in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and compared to standard technologies.

Reproductive Hazards Still Persist in the Microelectronics Industry: Increased Risk of Spontaneous Abortion and Menstrual Aberration among Female Workers in the Microelectronics Industry in South Korea.

PubMed

Kim, Inah; Kim, Myoung-Hee; Lim, Sinye

2015-01-01

Despite the global expansion of supply chains and changes to the production process, few studies since the mid-1990 s and 2000s have examined reproductive risks of the microelectronics industry; we examined the reproductive risks among female microelectronics workers in South Korea. Based on claim data from the National Health Insurance (2008-2012), we estimated age-specific rates of spontaneous abortion (SAB) and menstrual aberration (MA) among women aged 20 to 39 years. We compared data between microelectronics workers and three different control groups: economically inactive women, the working population as a whole, and workers employed in the bank industry. For an effect measure, age-stratified relative risks (RRs) were estimated. Female workers in the microelectronics industry showed significantly higher risk for SAB and MA compared to control groups. The RRs for SAB with reference to economically inactive women, working population, and bank workers in their twenties were 1.57, 1.40, and 1.37, respectively, and the RRs for MA among females in their twenties were 1.54, 1.38, and 1.48, respectively. For women in their thirties, RRs for SAB were 1.58, 1.67, and 1.13, and those for MA were 1.25, 1.35, and 1.23 compared to the three control populations, respectively. All RRs were statistically significant at a level of 0.05, except for the SAB case comparison with bank workers in their thirties. Despite technical innovations and health and safety measures, female workers in microelectronics industry in South Korea have high rates of SAB and MA, suggesting continued exposure to reproductive hazards. Further etiologic studies based on primary data collection and careful surveillance are required to confirm these results.

Microelectronics and nanotechnology, and the fractal-like structure of information, knowledge, and science

NASA Astrophysics Data System (ADS)

Nutu, Catalin Silviu; Axinte, Tiberiu

2016-12-01

The article is centralizing and is concentrating the information from a considerable amount of papers related to the field of microelectronics and nanotechnology and also provides an approach to science and to the future evolution of science, based on the theory of the fractals. The new science of microelectronics and nanotechnology is one of the best examples of how the science of future will look like, namely at the confluence of increasingly more other sciences, where increasingly more sciences are to be added in the structure of the new science and the role of the multidisciplinary and interdisciplinary is becoming more and more important. Although not giving explicit details (e.g. specific formulas) the theory of fractals is used in the paper to explain the way of generation of new science for the specific case of microelectronics and nanotechnology, but is also used in the paper to outline a different way to approach new science and eventually to approach new sciences to come. There are mainly two motivations for the present article, namely: on the one hand, the position of the microelectronics and nanotechnologies in the fractal-like structure of science, and, on the other hand, that much of the communication, information, knowledge and science transfer, dissemination and advancement in sciences are taking place using the new technologies related to microelectronics and nanotechnologies.

Visualization of electronic density

DOE PAGES

Grosso, Bastien; Cooper, Valentino R.; Pine, Polina; ...

2015-04-22

An atom’s volume depends on its electronic density. Although this density can only be evaluated exactly for hydrogen-like atoms, there are many excellent numerical algorithms and packages to calculate it for other materials. 3D visualization of charge density is challenging, especially when several molecular/atomic levels are intertwined in space. We explore several approaches to 3D charge density visualization, including the extension of an anaglyphic stereo visualization application based on the AViz package to larger structures such as nanotubes. We will describe motivations and potential applications of these tools for answering interesting questions about nanotube properties.

Beneficial effects of polyethylene packages containing micrometer-sized silver particles on the quality and shelf life of dried barberry (Berberis vulgaris).

PubMed

Motlagh, N Valipoor; Mosavian, M T Hamed; Mortazavi, S A; Tamizi, A

2012-01-01

In this research, the effects of low-density polyethylene (LDPE) packages containing micrometer-sized silver particles (LDPE-Ag) on microbial and sensory factors of dried barberry were investigated in comparison with the pure LDPE packages. LDPE-Ag packages with 1% and 2% concentrations of silver particles statistically caused a decrease in the microbial growth of barberry, especially in the case of mold and total bacteria count, compared with the pure LDPE packages. The taste, aroma, appearance, and total acceptance were evaluated by trained panelists using the 9-point hedonic scale. This test showed improvement of all these factors in the samples related to packages containing 1% and 2% concentrations of silver particles in comparison with other samples. Low-density polyethylene package containing micrometer-sized silver particles had beneficial effects on the sensory and microbial quality of barberry when compared with normal packing material. © 2011 Institute of Food Technologists®

Macro management of microelectronics in India in 1990s

NASA Astrophysics Data System (ADS)

Gupta, Parmod K.

1992-08-01

Development of microelectronics is taking place at a very fast rate all over the globe, including India. New technologies are introduced at very short intervals in order to capture the consumer market. It is essential that these technologies are managed properly at the macro level in order to bring the desired results. Microelectronics plays a very vital role in office automation for achieving cost effective results in a highly competitive environment. Introduction of various facilities like laser printers, photo copiers, dictaphone-selectronic boards, electronic telexes, teleconference rooms, telephone answering machines, computer, word processors, sensors, etc. have all revolutionized the industry. Keeping the above in view, the present and future status of microelectronics, with special emphasis on its role in office automation in India, are discussed in detail in this paper.

Center for Space Microelectronics Technology. 1993 Technical Report

NASA Technical Reports Server (NTRS)

1995-01-01

The 1993 Technical Report of the Jet Propulsion Laboratory Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the Center during the past year. The report lists 170 publications, 193 presentations, and 84 New Technology Reports and patents. The 1993 Technical Report of the Jet Propulsion Laboratory Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the Center during the past year. The report lists 170 publications, 193 presentations, and 84 New Technology Reports and patents.

Enabling laser applications in microelectronics manufacturing

NASA Astrophysics Data System (ADS)

Delmdahl, Ralph; Brune, Jan; Fechner, Burkhard; Senczuk, Rolf

2016-02-01

In this experimental study, we report on high-pulse-energy excimer laser drilling into high-performance build-up films which are pivotal in microelectronics manufacturing. Build-up materials ABF-GX13 from Ajinomoto as well as ZS-100 from Zeon Corporation are evaluated with respect to their viability for economic excimer laser-based micro-via formation. Excimer laser mask imaging projection at laser wavelengths of 193, 248 and 308 nm is employed to generate matrices of smaller micro-vias with different diameters and via pitches. High drilling quality is achievable for all excimer laser wavelengths with the fastest ablation rates measured in the case of 248 and 308 nm wavelengths. The presence of glass fillers in build-up films as in the ABF-GX13 material poses some limitations to the minimum achievable via diameter. However, surprisingly good drilling results are obtainable as long as the filler dimensions are well below the diameter of the micro-vias. Sidewall angles of vias are controllable by adjusting the laser energy density and pulse number. In this work, the structuring capabilities of excimer lasers in build-up films as to taper angle variations, attainable via diameters, edge-stop behavior and ablation rates will be elucidated.

Detection of solder bump defects on a flip chip using vibration analysis

NASA Astrophysics Data System (ADS)

Liu, Junchao; Shi, Tielin; Xia, Qi; Liao, Guanglan

2012-03-01

Flip chips are widely used in microelectronics packaging owing to the high demand of integration in IC fabrication. Solder bump defects on flip chips are difficult to detect, because the solder bumps are obscured by the chip and substrate. In this paper a nondestructive detection method combining ultrasonic excitation with vibration analysis is presented for detecting missing solder bumps, which is a typical defect in flip chip packaging. The flip chip analytical model is revised by considering the influence of spring mass on mechanical energy of the system. This revised model is then applied to estimate the flip chip resonance frequencies. We use an integrated signal generator and power amplifier together with an air-coupled ultrasonic transducer to excite the flip chips. The vibrations are measured by a laser scanning vibrometer to detect the resonance frequencies. A sensitivity coefficient is proposed to select the sensitive resonance frequency order for defect detection. Finite element simulation is also implemented for further investigation. The results of analytical computation, experiment, and simulation prove the efficacy of the revised flip chip analytical model and verify the effectiveness of this detection method. Therefore, it may provide a guide for the improvement and innovation of the flip chip on-line inspection systems.

Printing Peptide arrays with a complementary metal oxide semiconductor chip.

PubMed

Loeffler, Felix F; Cheng, Yun-Chien; Muenster, Bastian; Striffler, Jakob; Liu, Fanny C; Ralf Bischoff, F; Doersam, Edgar; Breitling, Frank; Nesterov-Mueller, Alexander

2013-01-01

: In this chapter, we discuss the state-of-the-art peptide array technologies, comparing the spot technique, lithographical methods, and microelectronic chip-based approaches. Based on this analysis, we describe a novel peptide array synthesis method with a microelectronic chip printer. By means of a complementary metal oxide semiconductor chip, charged bioparticles can be patterned on its surface. The bioparticles serve as vehicles to transfer molecule monomers to specific synthesis spots. Our chip offers 16,384 pixel electrodes on its surface with a spot-to-spot pitch of 100 μm. By switching the voltage of each pixel between 0 and 100 V separately, it is possible to generate arbitrary particle patterns for combinatorial molecule synthesis. Afterwards, the patterned chip surface serves as a printing head to transfer the particle pattern from its surface to a synthesis substrate. We conducted a series of proof-of-principle experiments to synthesize high-density peptide arrays. Our solid phase synthesis approach is based on the 9-fluorenylmethoxycarbonyl protection group strategy. After melting the particles, embedded monomers diffuse to the surface and participate in the coupling reaction to the surface. The method demonstrated herein can be easily extended to the synthesis of more complicated artificial molecules by using bioparticles with artificial molecular building blocks. The possibility of synthesizing artificial peptides was also shown in an experiment in which we patterned biotin particles in a high-density array format. These results open the road to the development of peptide-based functional modules for diverse applications in biotechnology.

Fractal dendrite-based electrically conductive composites for laser-scribed flexible circuits

PubMed Central

Yang, Cheng; Cui, Xiaoya; Zhang, Zhexu; Chiang, Sum Wai; Lin, Wei; Duan, Huan; Li, Jia; Kang, Feiyu; Wong, Ching-Ping

2015-01-01

Fractal metallic dendrites have been drawing more attentions recently, yet they have rarely been explored in electronic printing or packaging applications because of the great challenges in large-scale synthesis and limited understanding in such applications. Here we demonstrate a controllable synthesis of fractal Ag micro-dendrites at the hundred-gram scale. When used as the fillers for isotropically electrically conductive composites (ECCs), the unique three-dimensional fractal geometrical configuration and low-temperature sintering characteristic render the Ag micro dendrites with an ultra-low electrical percolation threshold of 0.97 vol% (8 wt%). The ultra-low percolation threshold and self-limited fusing ability may address some critical challenges in current interconnect technology for microelectronics. For example, only half of the laser-scribe energy is needed to pattern fine circuit lines printed using the present ECCs, showing great potential for wiring ultrathin circuits for high performance flexible electronics. PMID:26333352

Update on NASA Microelectronics Activities

NASA Technical Reports Server (NTRS)

Label, Kenneth A.; Sampson, Michael J.; Casey, Megan; Lauenstein, Jean-Marie

2017-01-01

Mission Statement: The NASA Electronic Parts and Packaging (NEPP) Program provides NASA's leadership for developing and maintaining guidance for the screening, qualification, test. and usage of EEE parts by NASA as well as in collaboration with other government Agencies and industry. NASA Space Technology Mission Directorate (STMD) "STMD rapidly develops, demonstrates, and infuses revolutionary, high-payoff technologies through transparent, collaborative partnerships, expanding the boundaries of the aerospace enterprise." Mission Statement: The Space Environments Testing Management Office (SETMO) will identify, prioritize, and manage a select suite of Agency key capabilities/assets that are deemed to be essential to the future needs of NASA or the nation, including some capabilities that lack an adequate business base over the budget horizon. NESC mission is to perform value-added independent testing, analysis, and assessments of NASA's high-risk projects to ensure safety and mission success. NASA Space Environments and Avionics Fellows as well as Radiation and EEE Parts Community of Practice (CoP) leads.

Zero-dimensional to three-dimensional nanojoining: current status and potential applications

DOE PAGES

Ma, Ying; Li, Hong; Bridges, Denzel; ...

2016-08-01

We report that the continuing miniaturization of microelectronics is pushing advanced manufacturing into nanomanufacturing. Nanojoining is a bottom-up assembly technique that enables functional nanodevice fabrication with dissimilar nanoscopic building blocks and/or molecular components. Various conventional joining techniques have been modified and re-invented for joining nanomaterials. Our review surveys recent progress in nanojoining methods, as compared to conventional joining processes. Examples of nanojoining are given and classified by the dimensionality of the joining materials. At each classification, nanojoining is reviewed and discussed according to materials specialties, low dimensional processing features, energy input mechanisms and potential applications. The preparation of new intermetallicmore » materials by reactive nanoscale multilayer foils based on self-propagating high-temperature synthesis is highlighted. This review will provide insight into nanojoining fundamentals and innovative applications in power electronics packaging, plasmonic devices, nanosoldering for printable electronics, 3D printing and space manufacturing.« less

Smart substrates: Making multi-chip modules smarter

NASA Astrophysics Data System (ADS)

Wunsch, T. F.; Treece, R. K.

1995-05-01

A novel multi-chip module (MCM) design and manufacturing methodology which utilizes active CMOS circuits in what is normally a passive substrate realizes the 'smart substrate' for use in highly testable, high reliability MCMS. The active devices are used to test the bare substrate, diagnose assembly errors or integrated circuit (IC) failures that require rework, and improve the testability of the final MCM assembly. A static random access memory (SRAM) MCM has been designed and fabricated in Sandia Microelectronics Development Laboratory in order to demonstrate the technical feasibility of this concept and to examine design and manufacturing issues which will ultimately determine the economic viability of this approach. The smart substrate memory MCM represents a first in MCM packaging. At the time the first modules were fabricated, no other company or MCM vendor had incorporated active devices in the substrate to improve manufacturability and testability, and thereby improve MCM reliability and reduce cost.

LIP: The Livermore Interpolation Package, Version 1.6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fritsch, F. N.

2016-01-04

This report describes LIP, the Livermore Interpolation Package. LIP was totally rewritten from the package described in [1]. In particular, the independent variables are now referred to as x and y, since it is a general-purpose package that need not be restricted to equation of state data, which uses variables ρ (density) and T (temperature).

Physical Limitations in Lithography for Microelectronics.

ERIC Educational Resources Information Center

Flavin, P. G.

1981-01-01

Describes techniques being used in the production of microelectronics kits which have replaced traditional optical lithography, including contact and optical projection printing, and X-ray and electron beam lithography. Also includes limitations of each technique described. (SK)

Design, processing and testing of LSI arrays, hybrid microelectronics task

NASA Technical Reports Server (NTRS)

Himmel, R. P.; Stuhlbarg, S. M.; Ravetti, R. G.; Zulueta, P. J.; Rothrock, C. W.

1979-01-01

Mathematical cost models previously developed for hybrid microelectronic subsystems were refined and expanded. Rework terms related to substrate fabrication, nonrecurring developmental and manufacturing operations, and prototype production are included. Sample computer programs were written to demonstrate hybrid microelectric applications of these cost models. Computer programs were generated to calculate and analyze values for the total microelectronics costs. Large scale integrated (LST) chips utilizing tape chip carrier technology were studied. The feasibility of interconnecting arrays of LSU chips utilizing tape chip carrier and semiautomatic wire bonding technology was demonstrated.

Reproductive Hazards Still Persist in the Microelectronics Industry: Increased Risk of Spontaneous Abortion and Menstrual Aberration among Female Workers in the Microelectronics Industry in South Korea

PubMed Central

Kim, Inah; Kim, Myoung-Hee; Lim, Sinye

2015-01-01

Objectives Despite the global expansion of supply chains and changes to the production process, few studies since the mid-1990s and 2000s have examined reproductive risks of the microelectronics industry; we examined the reproductive risks among female microelectronics workers in South Korea. Methods Based on claim data from the National Health Insurance (2008–2012), we estimated age-specific rates of spontaneous abortion (SAB) and menstrual aberration (MA) among women aged 20 to 39 years. We compared data between microelectronics workers and three different control groups: economically inactive women, the working population as a whole, and workers employed in the bank industry. For an effect measure, age-stratified relative risks (RRs) were estimated. Results Female workers in the microelectronics industry showed significantly higher risk for SAB and MA compared to control groups. The RRs for SAB with reference to economically inactive women, working population, and bank workers in their twenties were 1.57, 1.40, and 1.37, respectively, and the RRs for MA among females in their twenties were 1.54, 1.38, and 1.48, respectively. For women in their thirties, RRs for SAB were 1.58, 1.67, and 1.13, and those for MA were 1.25, 1.35, and 1.23 compared to the three control populations, respectively. All RRs were statistically significant at a level of 0.05, except for the SAB case comparison with bank workers in their thirties. Conclusions Despite technical innovations and health and safety measures, female workers in microelectronics industry in South Korea have high rates of SAB and MA, suggesting continued exposure to reproductive hazards. Further etiologic studies based on primary data collection and careful surveillance are required to confirm these results. PMID:25938673

Superconducting Microelectronics.

ERIC Educational Resources Information Center

Henry, Richard W.

1984-01-01

Discusses superconducting microelectronics based on the Josephson effect and its advantages over conventional integrated circuits in speed and sensitivity. Considers present uses in standards laboratories (voltage) and in measuring weak magnetic fields. Also considers future applications in superfast computer circuitry using Superconducting…

Microstructural effects on constitutive and fatigue fracture behavior of TinSilverCopper solder

NASA Astrophysics Data System (ADS)

Tucker, Jonathon P.

As microelectronic package construction becomes more diverse and complex, the need for accurate, geometry-independent material constitutive and failure models increases. Evaluations of packages based on accelerated environmental tests (such as accelerated thermal cycling or power cycling) only provide package-dependent reliability information. In addition, extrapolations of such test data to life predictions under field conditions are often empirical. Besides geometry, accelerated environmental test data must account for microstructural factors such as alloy composition or isothermal aging condition, resulting in expensive experimental variation. In this work, displacement-controlled, creep, and fatigue lap shear tests are conducted on specially designed SnAgCu test specimens with microstructures representative to those found in commercial microelectronic packages. The data are used to develop constitutive and fatigue fracture material models capable of describing deformation and fracture behavior for the relevant temperature and strain rate ranges. Furthermore, insight is provided into the microstructural variation of solder joints and the subsequent effect on material behavior. These models are appropriate for application to packages of any geometrical construction. The first focus of the thesis is on Pb-mixed SnAgCu solder alloys. During the transition from Pb-containing solders to Pb-free solders, joints composed of a mixture of SnPb and SnAgCu often result from either mixed assemblies or rework. Three alloys of 1, 5 and 20 weight percent Pb were selected so as to represent reasonable ranges of Pb contamination expected from different 63Sn37Pb components mixed with Sn3.0Ag0.5Cu. Displacement-controlled (constant strain rate) and creep tests were performed at temperatures of 25°C, 75°C, and 125°C using a double lap shear test setup that ensures a nearly homogeneous state of plastic strain at the joint interface. Rate-dependent constitutive models for Pb-contaminated SnAgCu solder alloys ranging from the traditional time-hardening creep model to the viscoplastic Anand model are described. The second focus of the thesis is on fatigue damage accumulation in SnAgCu solder alloys. While, typical fatigue fracture models are empirical, recently a non-empirical model termed Maximum Entropy Fracture Model (MEFM) was proposed. MEFM is a thermodynamically consistent and information theory inspired damage accumulation theory for ductile solids. This model has been validated recently for Sn3.8Ag0.7Cu solder alloy, and uses a single damage accumulation parameter to relate the probability of fracture to accumulated entropic dissipation. Isothermal cycling fatigue tests on Sn3.0Ag0.5Cu and mixed SnPb/Sn3.0Ag0.5Cu solder alloys at varying strain rates and temperatures are conducted using a custom-built microscale mechanical tester capable of submicron displacement resolution. MEFM is applied here in conjunction with the Anand viscoplasticity model to predict the softening occurring over successive cycles as a result of damage accumulation. The damage accumulation parameters for Sn3.0Ag0.5Cu in different aged states are related to a microstructural parameter which quantitatively describes the state of coarsening. In addition, damage accumulation parameters for the three mixed solder alloys are reported. This approach allows for a non-empirical prediction of both constitutive and fracture behavior of packages of different geometries and different microstructural states under thermo-mechanical fatigue. Approaches to solder joint reliability predictions from materials science and mechanics perspectives differ dramatically. Materials science methods identify key failure mechanisms, but most models cannot predict failure. In contrast, mechanics approaches often provide estimates of joint lifetime, but fail to provide insight into microstructural influences. This work attempts to connect the two fields by relating constitutive behavior and fatigue fracture models for different alloys and aging conditions to one or more microstructural parameters.

Parallel-plate heat pipe apparatus having a shaped wick structure

DOEpatents

Rightley, Michael J.; Adkins, Douglas R.; Mulhall, James J.; Robino, Charles V.; Reece, Mark; Smith, Paul M.; Tigges, Chris P.

2004-12-07

A parallel-plate heat pipe is disclosed that utilizes a plurality of evaporator regions at locations where heat sources (e.g. semiconductor chips) are to be provided. A plurality of curvilinear capillary grooves are formed on one or both major inner surfaces of the heat pipe to provide an independent flow of a liquid working fluid to the evaporator regions to optimize heat removal from different-size heat sources and to mitigate the possibility of heat-source shadowing. The parallel-plate heat pipe has applications for heat removal from high-density microelectronics and laptop computers.

Evidence for adverse reproductive outcomes among women microelectronic assembly workers.

PubMed Central

Huel, G; Mergler, D; Bowler, R

1990-01-01

Microelectronics assembly entails complex processes where several potentially fetotoxic chemical compounds are used extensively. This study was undertaken to assess the potential adverse reproductive outcomes among former women workers in a microelectronics assembly plant in New Mexico with respect to a comparable population from the same geographical region and to examine the relation between these outcomes and employment history in this plant. After matching a pool of 143 former microelectronic female workers and 105 referents, 90 former microelectronic female worker-referent pairs were constituted (representing 302 and 324 pregnancies in former workers and referents respectively). The odds ratio (for pair matching design) of spontaneous abortion among women workers, before beginning to assemble microelectronic components, was 0.9 (chi 2 = 0.04; NS). After the beginning of employment this odds ratio became 5.6 (chi 2 = 9.8; p less than 1%). This estimated odds ratio decreased to 4.0, taking into account the increased risk for spontaneous abortion in previous pregnancies before employment (chi 2 = 5.4; p less than 5%). It was not possible to determine if this effect was reversible owing to the small number of pairs available after employment. The findings of this study corroborate the results of former studies that suggest a potential association between electronic manufacturing activity and risk of spontaneous abortion. Although the organic solvents were suspected of being the potential risk factor, this study was inconclusive from this point of view. Nevertheless, these investigations may provide some insight into reproductive outcomes among female workers exposed to solvents. PMID:2378817

Center for Space Microelectronics Technology 1988-1989 technical report

NASA Technical Reports Server (NTRS)

Olsen, Peggy

1990-01-01

The 1988 to 1989 Technical Report of the JPL Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the center. Listed are 321 publications, 282 presentations, and 140 new technology reports and patents.

Center for Space Microelectronics Technology

NASA Technical Reports Server (NTRS)

1991-01-01

The 1990 technical report of the Jet Propulsion Laboratory Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the center during 1990. The report lists 130 publications, 226 presentations, and 87 new technology reports and patents.

Center for Space Microelectronics Technology

NASA Technical Reports Server (NTRS)

1992-01-01

The 1991 Technical Report of the Jet Propulsion Laboratory Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the Center during the past year. The report lists 193 publications, 211 presentations, and 125 new technology reports and patents.

Effects of doping Na and Cl atom on electronic structure of silicene: Density functional theory calculation

NASA Astrophysics Data System (ADS)

Pamungkas, Mauludi Ariesto; Sobirin, Kafi; Abdurrouf

2018-04-01

Silicene is a material in which silicon atoms are packed in two-dimensional hexagonal lattice, similar to that of graphene. Compared to graphene, silicene has promising potential to be applied in microelectronic technology because of its compatibility with silicon comonly used in semiconducting devices. Natrium and chlorine are easy to extract and can be used as dopants in FET (Field Effect Transistor). In this work, the effects of adsorption energy and electronic structure of silicene to both natrium and chlorine atoms are calculated with Density Functional Theory (DFT). The results show that dopings of Na transform silicene which is initially semimetal into a metal. Then dopings of Cl Top-site transform silicene into a semiconducting material and doping of Na and Cl simultaneously transfoms silicene into a conducting material.

Enhanced energy harvesting in commercial ferroelectric materials

NASA Astrophysics Data System (ADS)

Patel, Satyanarayan; Chauhan, Aditya; Vaish, Rahul

2014-04-01

Ferroelectric materials are used in a number of applications ranging from simple sensors and actuators to ferroelectric random access memories (FRAMs), transducers, health monitoring system and microelectronics. The multiphysical coupling ability possessed by these materials has been established to be useful for energy harvesting applications. However, conventional energy harvesting techniques employing ferroelectric materials possess low energy density. This has prevented the successful commercialization of ferroelectric based energy harvesting systems. In this context, the present study aims at proposing a novel approach for enhanced energy harvesting using commercially available ferroelectric materials. This technique was simulated to be used for two commercially available piezoelectric materials namely PKI-552 and APCI-840, soft and hard lead-zirconate-titanate (PZT) pervoskite ceramics, respectively. It was observed that a maximum energy density of 348 kJm-3cycle-1 can be obtained for cycle parameters of (0-1 ton compressive stress and 1-25 kV.cm-1 electric field) using APCI-840. The reported energy density is several hundred times larger than the maximum energy density reported in the literature for vibration harvesting systems.

Thermoelectric Outer Planets Spacecraft (TOPS) electronic packaging and cabling development summary report

NASA Technical Reports Server (NTRS)

Dawe, R. H.; Arnett, J. C.

1974-01-01

Electronic packaging and cabling activities performed in support of the Thermoelectric Outer Planets Spacecraft (TOPS) Advanced Systems Technology (AST) project are detailed. It describes new electronic compartment, electronic assembly, and module concepts, and a new high-density, planar interconnection technique called discrete multilayer (DML). Development and qualification of high density cabling techniques, using small gage wire and microminiature connectors, are also reported.

Limiting Surface Density Method Adapted to Large Arrays of Heterogeneous Shipping Packages with Nonlinear Responses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stover, Tracy E.; Baker, James S.; Ratliff, Michael D.

The classic Limiting Surface Density (LSD) method is an empirical calculation technique for analyzing and setting mass limits for fissile items in storage arrays. LSD is a desirable method because it can reduce or eliminate the need for lengthy detailed Monte Carlo models of storage arrays. The original (or classic) method was developed based on idealized arrays of bare spherical metal items in air-spaced cubic units in a water-reflected cubic array. In this case, the geometric and material-based surface densities were acceptably correlated by linear functions. Later updates to the method were made to allow for concrete reflection rather thanmore » water, cylindrical masses rather than spheres, different material forms, and noncubic arrays. However, in the intervening four decades since those updates, little work has been done to update the method, especially for use with contemporary highly heterogeneous shipping packages that are noncubic and stored in noncubic arrays. In this work, the LSD method is reevaluated for application to highly heterogeneous shipping packages for fissile material. The package modeled is the 9975 shipping package, currently the primary package used to store fissile material at Savannah River Site’s K-Area Complex. The package is neither cubic nor rectangular but resembles nested cylinders of stainless steel, lead, aluminum, and Celotex. The fissile content is assumed to be a cylinder of plutonium metal. The packages may be arranged in arrays with both an equal number of packages per side (package cubic) and an unequal number of packages per side (noncubic). The cubic arrangements are used to derive the 9975-specific material and geometry constants for the classic linear form LSD method. The linear form of the LSD, with noncubic array adjustment, is applied and evaluated against computational models for these packages to determine the critical unit fissile mass. Sensitivity equations are derived from the classic method, and these are also used to make projections of the critical unit fissile mass. It was discovered that the heterogeneous packages have a nonlinear surface density versus critical mass relationship compared to the acceptably linear response of bare spherical fissile masses. Methodology is developed to address the nonlinear response. In so doing, the solution to the nonlinear LSD method becomes decoupled from the critical mass of a single unit, adding to its flexibility. The ability of the method to predict changes in neutron multiplication due to perturbations in a parameter is examined to provide a basis for analyzing upset conditions. In conclusion, a full rederivation of the classic LSD method from diffusion theory is also included as this was found to be lacking in the available literature.« less

Limiting Surface Density Method Adapted to Large Arrays of Heterogeneous Shipping Packages with Nonlinear Responses

DOE PAGES

Stover, Tracy E.; Baker, James S.; Ratliff, Michael D.; ...

2018-03-02

The classic Limiting Surface Density (LSD) method is an empirical calculation technique for analyzing and setting mass limits for fissile items in storage arrays. LSD is a desirable method because it can reduce or eliminate the need for lengthy detailed Monte Carlo models of storage arrays. The original (or classic) method was developed based on idealized arrays of bare spherical metal items in air-spaced cubic units in a water-reflected cubic array. In this case, the geometric and material-based surface densities were acceptably correlated by linear functions. Later updates to the method were made to allow for concrete reflection rather thanmore » water, cylindrical masses rather than spheres, different material forms, and noncubic arrays. However, in the intervening four decades since those updates, little work has been done to update the method, especially for use with contemporary highly heterogeneous shipping packages that are noncubic and stored in noncubic arrays. In this work, the LSD method is reevaluated for application to highly heterogeneous shipping packages for fissile material. The package modeled is the 9975 shipping package, currently the primary package used to store fissile material at Savannah River Site’s K-Area Complex. The package is neither cubic nor rectangular but resembles nested cylinders of stainless steel, lead, aluminum, and Celotex. The fissile content is assumed to be a cylinder of plutonium metal. The packages may be arranged in arrays with both an equal number of packages per side (package cubic) and an unequal number of packages per side (noncubic). The cubic arrangements are used to derive the 9975-specific material and geometry constants for the classic linear form LSD method. The linear form of the LSD, with noncubic array adjustment, is applied and evaluated against computational models for these packages to determine the critical unit fissile mass. Sensitivity equations are derived from the classic method, and these are also used to make projections of the critical unit fissile mass. It was discovered that the heterogeneous packages have a nonlinear surface density versus critical mass relationship compared to the acceptably linear response of bare spherical fissile masses. Methodology is developed to address the nonlinear response. In so doing, the solution to the nonlinear LSD method becomes decoupled from the critical mass of a single unit, adding to its flexibility. The ability of the method to predict changes in neutron multiplication due to perturbations in a parameter is examined to provide a basis for analyzing upset conditions. In conclusion, a full rederivation of the classic LSD method from diffusion theory is also included as this was found to be lacking in the available literature.« less

Thermo-mechanical properties and integrity of metallic interconnects in microelectronics

NASA Astrophysics Data System (ADS)

Ege, Efe Sinan

In this dissertation, combined numerical (Finite Element Method) and experimental efforts were undertaken to study thermo-mechanical behavior in microelectronic devices. Interconnects, including chip-level metallization and package-level solder joints, are used to join many of the circuit parts in modern equipment. The dissertation is structured into six independent studies after the introductory chapter. The first two studies focus on thermo-mechanical fatigue of solder joints. Thermo-mechanical fatigue, in the form of damage along a microstructurally coarsened region in tin-lead solder, is analyzed along with the effects of intermetallic morphology. Also, lap-shear testing is modeled to characterize the joint and to investigate the validity of experimental data from different solder and substrate geometries. In the third study, the effects of pre-machined holes on strain localization and overall ductility in bulk eutectic tin-lead alloy is examined. Finite element analyses, taking into account the viscoplastic response, were carried out to provide a mechanistic rationale to corroborate the experimental findings. The fourth study concerns chip-level copper interconnects. Various combinations of oxide and polymer-based low-k dielectric schemes, with and without the thin barrier layers surrounding the Cu line, are considered. Attention is devoted to the thermal stress and strain fields and their dependency on material properties, geometry, and modeling details. This study is followed by a chapter on atomistics of interface-mediated plasticity in thin metallic films. The objective is to gain fundamental insight into the underlying mechanisms affecting the mechanical response of nanoscale thin films. The final study investigates the effect of microstructural heterogeneity on indentation response, for the purpose of raising awareness of the uncertainties involved in applying indentation techniques in probing mechanical properties of miniaturized devices.

Labour-Saving versus Work-Amplifying Effects of Micro-Electronics.

ERIC Educational Resources Information Center

Watanabe, Susumu

1986-01-01

This article argues that the labor-displacement effect of microelectronic machinery, especially numerically controlled machine tools and robots, has been exaggerated and that people tend to confuse the impact of intensified international competition with that of the new technology. (Author/CT)

Analysis of LDLR mutations in familial hypercholesterolemia patients in Greece by use of the NanoChip microelectronic array technology.

PubMed

Laios, Eleftheria; Drogari, Euridiki

2006-12-01

Three mutations in the low density lipoprotein receptor (LDLR) gene account for 49% of familial hypercholesterolemia (FH) cases in Greece. We used the microelectronic array technology of the NanoChip Molecular Biology Workstation to develop a multiplex method to analyze these single-nucleotide polymorphisms (SNPs). Primer pairs amplified the region encompassing each SNP. The biotinylated PCR amplicon was electronically addressed to streptavidin-coated microarray sites. Allele-specific fluorescently labeled oligonucleotide reporters were designed and used for detection of wild-type and SNP sequences. Genotypes were compared to PCR-restriction fragment length polymorphism (PCR-RFLP). We developed three monoplex assays (1 SNP/site) and an optimized multiplex assay (3SNPs/site). We performed 92 Greece II, 100 Genoa, and 98 Afrikaner-2 NanoChip monoplex assays (addressed to duplicate sites and analyzed separately). Of the 580 monoplex genotypings (290 samples), 579 agreed with RFLP. Duplicate sites of one sample were not in agreement with each other. Of the 580 multiplex genotypings, 576 agreed with the monoplex results. Duplicate sites of three samples were not in agreement with each other, indicating requirement for repetition upon which discrepancies were resolved. The multiplex assay detects common LDLR mutations in Greek FH patients and can be extended to accommodate additional mutations.

Microelectronics and Computers in Medicine.

ERIC Educational Resources Information Center

Meindl, James D.

1982-01-01

The use of microelectronics and computers in medicine is reviewed, focusing on medical research; medical data collection, storage, retrieval, and manipulation; medical decision making; computed tomography; ultrasonic imaging; role in clinical laboratories; and use as adjuncts for diagnostic tests, monitors of critically-ill patients, and with the…

Recent advances in photonics packaging materials

NASA Astrophysics Data System (ADS)

Zweben, Carl

2006-02-01

There are now over a dozen low-CTE materials with thermal conductivities between that of copper (400 w/m-K) and over 4X copper (1700 W/m-K). Most have low densities. For comparison, traditional low-CTE packaging materials like copper/tungsten have thermal conductivities that are little or no better than that of aluminum (200 W/m-K) and high densities. There are also low-density thermal insulators with low CTEs. Some advanced materials are low cost. Most do not outgas. They have a wide range of electrical properties that can be used to minimize electromagnetic emissions or provide EMI shielding. Several are now in commercial and aerospace applications, including laser diode packages; light-emitting diode (LED) packages; thermoelectric cooler bases, plasma displays; power modules; servers; laptops; heat sinks; thermally conductive, low-CTE printed circuit boards; and printed circuit board cold plates. Advanced material payoffs include: improved thermal performance, reliability, alignment and manufacturing yield; reduced thermal stresses and heating power requirements; simplified thermal design; enablement of hard solder direct attach; weight savings up to 85%; size reductions up to 65%; and lower cost. This paper discusses the large and increasing number of advanced packaging materials, including properties, development status, applications, increasing manufacturing yield, cost, lessons learned and future directions, including nanocomposites.

Proceedings of the International Conference on Vacuum Microelectronics (2nd) Held in Bath England on 24-26 July 1989: Vacuum Microelectronics

DTIC Science & Technology

1989-07-26

resulting Laplacian matrix. This © 1989 lOP Publishing Ltd l • m m i m mIlia ItoI 110 Vacuum microelectronics 89 approach does not easily yield accurate...Schottky diodes p-InP-Ag A L Musatov, S L Filippov and VL Korotkikh 57-60 Stimulated cold-cathode emission from metal electrodes coated with Langmuir...quantum transport K L Jensen and FA Buot 141-144 Silicon cold cathodes based on PIN diodes P A M van der Heide, G G P van Gorkom, A M E Hoeberechts, A A

Nanosatellite program at Sandia National Laboratories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reynolds, D.A.; Kern, J.P.; Schoeneman, J.L.

1999-11-11

The concept of building extremely small satellites which, either independently or as a collective, can perform missions which are comparable to their much larger cousins, has fascinated scientists and engineers for several years now. In addition to the now commonplace microelectronic integrated circuits, the more recent advent of technologies such as photonic integrated circuits (PIC's) and micro-electromechanical systems (MEMS) have placed such a goal within their grasp. Key to the acceptance of this technology will be the ability to manufacture these very small satellites in quantity without sacrificing their performance or versatility. In support of its nuclear treaty verification, proliferationmore » monitoring and other remote sensing missions, Sandia National laboratories has had a 35-year history of providing highly capable systems, densely packaged for unintrusive piggyback missions on government satellites. As monitoring requirements have become more challenging and remote sensing technologies become more sophisticated, packaging greater capability into these systems has become a requirement. Likewise, dwindling budgets are pushing satellite programs toward smaller and smaller platforms, reinforcing the need for smaller, cheaper satellite systems. In the next step of its miniaturization plan, Sandia has begun development of technologies for a highly integrated miniature satellite. The focus of this development is to achieve nanosat or smaller dimensions while maintaining significant capability utilizing semiconductor wafer-level integration and, at the same time promoting affordability through modular generic construction.« less

Comparative Advantages in Microelectronics,

DTIC Science & Technology

The initial point of departure for analyzing comparative advantages in microelectronics is to make certain explicit assumptions. First, technology...changes conditions but does not determine comparative advantages . Secondly, the entire industrial infrastructure is becoming increasingly abstract...that informatics will profoundly affect the productive infrastructure and the international division of labour.

76 FR 10395 - BreconRidge Manufacturing Solutions, Now Known as Sanmina-SCI Corporation, Division...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-24

... Solutions, Now Known as Sanmina-SCI Corporation, Division Optoelectronic and Microelectronic Design and Manufacturing, a Subsidiary of Sanmina-SCI Corporation, Including On- Site Leased Workers From Kelly Services... Manufacturing Solutions, now known as Sanmina-SCI Corporation, Division Optoelectronic and Microelectronic...

Sodium Reduction in US Households' Packaged Food and Beverage Purchases, 2000 to 2014.

PubMed

Poti, Jennifer M; Dunford, Elizabeth K; Popkin, Barry M

2017-07-01

Initiatives to reduce sodium in packaged foods have been launched in the United States, yet corresponding changes in the amount of sodium that US households obtain from packaged foods have not been evaluated, to our knowledge. To assess 15-year changes in the amount of sodium that US households acquire from packaged food purchases, the sodium content of purchases, and the proportion of households that have purchases with optimal sodium density. Longitudinal study of US households in the 2000 to 2014 Nielsen Homescan Consumer Panel, a population-based sample of households that used barcode scanners to record all packaged foods purchased throughout the year. Time-varying brand- and product-specific nutrition information was used for 1 490 141 products. Sociodemographic-adjusted changes in mean sodium per capita (mg/d) and sodium content (mg/100 g), overall and for top food group sources of sodium, and the proportion of households that have total purchases with sodium density of 1.1 mg/kcal or less. In a nationwide sample of 172 042 US households (754 608 year-level observations), the amount of sodium that households acquired from packaged food and beverage purchases decreased significantly between 2000 and 2014 by 396 mg/d (95% CI, -407 to -385 mg/d) per capita. The sodium content of households' packaged food purchases decreased significantly during this 15-year period by 49 mg/100 g (95% CI, -50 to -48 mg/100 g), a 12.0% decline; decreases began in 2005 and continued through 2014. Moreover, the sodium content of households' purchases decreased significantly for all top food sources of sodium between 2000 and 2014, including declines of more than 100 mg/100 g for condiments, sauces, and dips (-114 mg/100 g; 95% CI, -117 to -111 mg/100 g) and salty snacks (-142 mg/100 g; 95% CI, -144 to -141 mg/100 g). However, in all years, less than 2% of US households had packaged food and beverage purchases with sodium density of 1.1 mg/kcal or less. In this nationwide study, significant reductions in sodium from packaged food purchases were achieved in the past 15 years. Nonetheless, most US households had food and beverage purchases with excessive sodium density. Findings suggest that more concerted sodium reduction efforts are needed in the United States.

Chemically stabilized epitaxial wurtzite-BN thin film

NASA Astrophysics Data System (ADS)

Vishal, Badri; Singh, Rajendra; Chaturvedi, Abhishek; Sharma, Ankit; Sreedhara, M. B.; Sahu, Rajib; Bhat, Usha; Ramamurty, Upadrasta; Datta, Ranjan

2018-03-01

We report on the chemically stabilized epitaxial w-BN thin film grown on c-plane sapphire by pulsed laser deposition under slow kinetic condition. Traces of no other allotropes such as cubic (c) or hexagonal (h) BN phases are present. Sapphire substrate plays a significant role in stabilizing the metastable w-BN from h-BN target under unusual PLD growth condition involving low temperature and pressure and is explained based on density functional theory calculation. The hardness and the elastic modulus of the w-BN film are 37 & 339 GPa, respectively measured by indentation along <0001> direction. The results are extremely promising in advancing the microelectronic and mechanical tooling industry.

Embedded CMOS basecalling for nanopore DNA sequencing.

PubMed

Chengjie Wang; Junli Zheng; Magierowski, Sebastian; Ghafar-Zadeh, Ebrahim

2016-08-01

DNA sequencing based on nanopore sensors is now entering the marketplace. The ability to interface this technology to established CMOS microelectronics promises significant improvements in functionality and miniaturization. Among the key functions to benefit from this interface will be basecalling, the conversion of raw electronic molecular signatures to nucleotide sequence predictions. This paper presents the design and performance potential of custom CMOS base-callers embedded alongside nanopore sensors. A basecalliing architecture implemented in 32-nm technology is discussed with the ability to process the equivalent of 20 human genomes per day in real-time at a power density of 5 W/cm2 assuming a 3-mer nanopore sensor.

Managing the Manpower Aspects of Applying Micro-Electronics Technology.

ERIC Educational Resources Information Center

Thornton, P.; Routledge, C.

1980-01-01

Outlines major effects that the application of micro-electronics devices in products/processes and in office systems will have on future manpower and skill requirements in manufacturing organizations. Identifies the type of problems these changes will pose for manpower managers. Provides general guidelines for the successful management of these…

Teaching and Learning in a Microelectronic Age.

ERIC Educational Resources Information Center

Shane, Harold G.

General background information on microtechnologies with implications for educators provides an introduction to this review of past and current developments in microelectronics and specific ways in which the microchip is permeating society, creating problems and opportunities both in the workplace and the home. Topics discussed in the first of two…

Polymorphism of DNA conformation inside the bacteriophage capsid.

PubMed

Leforestier, Amélie

2013-03-01

Double-stranded DNA bacteriophage genomes are packaged into their icosahedral capsids at the highest densities known so far (about 50 % w:v). How the molecule is folded at such density and how its conformation changes upon ejection or packaging are fascinating questions still largely open. We review cryo-TEM analyses of DNA conformation inside partially filled capsids as a function of the physico-chemical environment (ions, osmotic pressure, temperature). We show that there exists a wide variety of DNA conformations. Strikingly, the different observed structures can be described by some of the different models proposed over the years for DNA organisation inside bacteriophage capsids: either spool-like structures with axial or concentric symmetries, or liquid crystalline structures characterised by a DNA homogeneous density. The relevance of these conformations for the understanding of DNA folding and unfolding upon ejection and packaging in vivo is discussed.

Application of laser driven fast high density plasma blocks for ion implantation

NASA Astrophysics Data System (ADS)

Sari, Amir H.; Osman, F.; Doolan, K. R.; Ghoranneviss, M.; Hora, H.; Höpfl, R.; Benstetter, G.; Hantehzadeh, M. H.

2005-10-01

The measurement of very narrow high density plasma blocks of high ion energy from targets irradiated with ps-TW laser pulses based on a new skin depth interaction process is an ideal tool for application of ion implantation in materials, especially of silicon, GaAs, or conducting polymers, for micro-electronics as well as for low cost solar cells. A further application is for ion sources in accelerators with most specifications of many orders of magnitudes advances against classical ion sources. We report on near band gap generation of defects by implantation of ions as measured by optical absorption spectra. A further connection is given for studying the particle beam transforming of n-type semiconductors into p-type and vice versa as known from sub-threshold particle beams. The advantage consists in the use of avoiding aggressive or rare chemical materials when using the beam techniques for industrial applications.

States of phage T3/T7 capsids: buoyant density centrifugation and cryo-EM.

PubMed

Serwer, Philip; Wright, Elena T; Demeler, Borries; Jiang, Wen

2018-04-01

Mature double-stranded DNA bacteriophages have capsids with symmetrical shells that typically resist disruption, as they must to survive in the wild. However, flexibility and associated dynamism assist function. We describe biochemistry-oriented procedures used to find previously obscure flexibility for capsids of the related phages, T3 and T7. The primary procedures are hydration-based buoyant density ultracentrifugation and purified particle-based cryo-electron microscopy (cryo-EM). We review the buoyant density centrifugation in detail. The mature, stable T3/T7 capsid is a shell flexibility-derived conversion product of an initially assembled procapsid (capsid I). During DNA packaging, capsid I expands and loses a scaffolding protein to form capsid II. The following are observations made with capsid II. (1) The in vivo DNA packaging of wild type T3 generates capsid II that has a slight (1.4%), cryo-EM-detected hyper-expansion relative to the mature phage capsid. (2) DNA packaging in some altered conditions generates more extensive hyper-expansion of capsid II, initially detected by hydration-based preparative buoyant density centrifugation in Nycodenz density gradients. (3) Capsid contraction sometimes occurs, e.g., during quantized leakage of DNA from mature T3 capsids without a tail.

LTCC interconnects in microsystems

NASA Astrophysics Data System (ADS)

Rusu, Cristina; Persson, Katrin; Ottosson, Britta; Billger, Dag

2006-06-01

Different microelectromechanical system (MEMS) packaging strategies towards high packaging density of MEMS devices and lower expenditure exist both in the market and in research. For example, electrical interconnections and low stress wafer level packaging are essential for improving device performance. Hybrid integration of low temperature co-fired ceramics (LTCC) with Si can be a way for an easier packaging system with integrated electrical interconnection, and as well towards lower costs. Our research on LTCC-Si integration is reported in this paper.

Application of analytical redundancy management to Shuttle crafts. [computerized simulation of microelectronic implementation

NASA Technical Reports Server (NTRS)

Montgomery, R. C.; Tabak, D.

1979-01-01

The study involves the bank of filters approach to analytical redundancy management since this is amenable to microelectronic implementation. Attention is given to a study of the UD factorized filter to determine if it gives more accurate estimates than the standard Kalman filter when data processing word size is reduced. It is reported that, as the word size is reduced, the effect of modeling error dominates the filter performance of the two filters. However, the UD filter is shown to maintain a slight advantage in tracking performance. It is concluded that because of the UD filter's stability in the serial processing mode, it remains the leading candidate for microelectronic implementation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Albert G. Baca; Edwin J. Heller; Gregory C. Frye-Mason

High sensitivity acoustic wave chemical microsensors are being developed on GaAs substrates. These devices take advantage of the piezoelectric properties of GaAs as well as its mature microelectronics fabrication technology and nascent micromachining technology. The design, fabrication, and response of GaAs SAW chemical microsensors are reported. Functional integrated GaAs SAW oscillators, suitable for chemical sensing, have been produced. The integrated oscillator requires 20 mA at 3 VK, operates at frequencies up to 500 MHz, and occupies approximately 2 mmz. Discrete GaAs sensor components, including IC amplifiers, SAW delay lines, and IC phase comparators have been fabricated and tested. A temperaturemore » compensation scheme has been developed that overcomes the large temperature dependence of GaAs acoustic wave devices. Packaging issues related to bonding miniature flow channels directly to the GaAs substrates have been resolved. Micromachining techniques for fabricating FPW and TSM microsensors on thin GaAs membranes are presented and GaAs FPW delay line performance is described. These devices have potentially higher sensitivity than existing GaAs and quartz SAW sensors.« less

Designing a chevron unit for a microelectronic position-sensitive detector with two microchannel plates

NASA Astrophysics Data System (ADS)

Kosulya, A. V.; Verbitskii, V. G.

2017-09-01

The dependence of the transverse section of an electron beam on the distance between plates and on the accelerating potential difference is determined for a chevron unit of a microelectronic position-sensitive detector (MPSD) with two microchannel plates. The geometry of the MPSD chevron unit is designed and optimized.

Microelectronic Information Processing Systems: Computing Systems. Summary of Awards Fiscal Year 1994.

ERIC Educational Resources Information Center

National Science Foundation, Arlington, VA. Directorate for Computer and Information Science and Engineering.

The purpose of this summary of awards is to provide the scientific and engineering communities with a summary of the grants awarded in 1994 by the National Science Foundation's Division of Microelectronic Information Processing Systems. Similar areas of research are grouped together. Grantee institutions and principal investigators are identified…

Complex VLSI Feature Comparison for Commercial Microelectronics Verification

DTIC Science & Technology

2014-03-27

69 4.2.4 Circuit E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 4.3 Summary...used for high-performance consumer microelectronics. Volume is a significant factor in constraining the technology limit for defense circuits, but it...surveyed in a 2010 Department of Commerce report found counterfeit chips difficult to identify due to improved fabrication quality in overseas counterfeit

Center for space microelectronics technology

NASA Technical Reports Server (NTRS)

1993-01-01

The 1992 Technical Report of the Jet Propulsion Laboratory Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the center during the past year. The report lists 187 publications, 253 presentations, and 111 new technology reports and patents in the areas of solid-state devices, photonics, advanced computing, and custom microcircuits.

The large scale microelectronics Computer-Aided Design and Test (CADAT) system

NASA Technical Reports Server (NTRS)

Gould, J. M.

1978-01-01

The CADAT system consists of a number of computer programs written in FORTRAN that provide the capability to simulate, lay out, analyze, and create the artwork for large scale microelectronics. The function of each software component of the system is described with references to specific documentation for each software component.

The Tao of Microelectronics

NASA Astrophysics Data System (ADS)

Zhang, Yumin

2014-12-01

Microelectronics is a challenging course to many undergraduate students and is often described as very messy. Before taking this course, all the students have learned circuit analysis, where basically all the problems can be solved by applying Kirchhoff's laws. In addition, most engineering students have also learned engineering mechanics: statics and dynamics, where Newton's laws and related principles can be applied in solving all the problems. However, microelectronics is not as clean as these courses. There are hundreds of equations for different circuits, and it is impossible to remember which equation should be applied to which circuit. One of the common pitfalls in learning this course is over-focusing at the equation level and ignoring the ideas (Tao) behind it. Unfortunately, these ideas are not summarized and emphasized in most microelectronics textbooks, though they cover various electronic circuits comprehensively. Therefore, most undergraduate students feel at a loss when they start to learn this topic. This book tries to illustrate the major ideas and the basic analysis techniques, so that students can derive the right equations easily when facing an electronic circuit.

Monitoring Composite Material Pressure Vessels with a Fiber-Optic/Microelectronic Sensor System

NASA Technical Reports Server (NTRS)

Klimcak, C.; Jaduszliwer, B.

1995-01-01

We discuss the concept of an integrated, fiber-optic/microelectronic distributed sensor system that can monitor composite material pressure vessels for Air Force space systems to provide assessments of the overall health and integrity of the vessel throughout its entire operating history from birth to end of life. The fiber optic component would include either a semiconductor light emitting diode or diode laser and a multiplexed fiber optic sensing network incorporating Bragg grating sensors capable of detecting internal temperature and strain. The microelectronic components include a power source, a pulsed laser driver, time domain data acquisition hardware, a microprocessor, a data storage device, and a communication interface. The sensing system would be incorporated within the composite during its manufacture. The microelectronic data acquisition and logging system would record the environmental conditions to which the vessel has been subjected to during its storage and transit, e.g., the history of thermal excursions, pressure loading data, the occurrence of mechanical impacts, the presence of changing internal strain due to aging, delamination, material decomposition, etc. Data would be maintained din non-volatile memory for subsequent readout through a microcomputer interface.

Materials for High-Density Electronic Packaging and Interconnection

DTIC Science & Technology

1990-04-10

play a prominent role in the future. Glass and Porcelain The earliest use of electronic ceramics was as insulators for carrying telegraph lines...Administration 61L & CORES , (Ot. stem. SAI WCJm 76. LOISS (C". SUMt *oW WVCf B’%2101 Constitution Avenue. N W Washington, D.C. 20418 Washington. D.C. 20301 G...Density Packaging 84 Tape Automated Bonding 87 Diamond 88 Superconductors 88 Composites 89 Materials for Very-High-Frequency Digital Systems 91

Amorphous Metal Oxide Thin Films from Aqueous Precursors: New Routes to High-kappa Dielectrics, Impact of Annealing Atmosphere Humidity, and Elucidation of Non-Uniform Composition Profiles

NASA Astrophysics Data System (ADS)

Woods, Keenan N.

Metal oxide thin films serve as critical components in many modern technologies, including microelectronic devices. Industrial state-of-the-art production utilizes vapor-phase techniques to make high-quality (dense, smooth, uniform) thin film materials. However, vapor-phase techniques require large energy inputs and expensive equipment and precursors. Solution-phase routes to metal oxides have attracted great interest as cost-effective alternatives to vapor-phase methods and also offer the potential of large-area coverage, facile control of metal composition, and low-temperature processing. Solution deposition has previously been dominated by sol-gel routes, which utilize organic ligands, additives, and/or solvents. However, sol-gel films are often porous and contain residual carbon impurities, which can negatively impact device properties. All-inorganic aqueous routes produce dense, ultrasmooth films without carbon impurities, but the mechanisms involved in converting aqueous precursors to metal oxides are virtually unexplored. Understanding these mechanisms and the parameters that influence them is critical for widespread use of aqueous approaches to prepare microelectronic components. Additionally, understanding (and controlling) density and composition inhomogeneities is important for optimizing electronic properties. An overview of deposition approaches and the challenges facing aqueous routes are presented in Chapter I. A summary of thin film characterization techniques central to this work is given in Chapter II. This dissertation contributes to the field of solution-phase deposition by focusing on three areas. First, an all-inorganic aqueous route to high-kappa metal oxide dielectrics is developed for two ternary systems. Chapters III and IV detail the film formation chemistry and film properties of lanthanum zirconium oxide (LZO) and zirconium aluminum oxide (ZAO), respectively. The functionality of these dielectrics as device components is also demonstrated. Second, the impact of steam annealing on the evolution of aqueous-derived films is reported. Chapter V demonstrates that steam annealing lowers processing temperatures by effectively reducing residual counterion content, improving film stability with respect to water absorption, and enhancing dielectric properties of LZO films. Third, density and composition inhomogeneities in aqueous-derived films are investigated. Chapters VI and VII examine density inhomogeneities in single- and multi-metal component thin films, respectively, and show that these density inhomogeneities are related to inhomogeneous metal component distributions. This dissertation includes previously published coauthored material.

Cost-Effectiveness of Rural Incentive Packages for Graduating Medical Students in Lao PDR

PubMed Central

Keuffel, Eric; Jaskiewicz, Wanda; Theppanya, Khampasong; Tulenko, Kate

2017-01-01

Background: The dearth of health workers in rural settings in Lao People’s Democratic Republic (PDR) and other developing countries limits healthcare access and outcomes. In evaluating non-wage financial incentive packages as a potential policy option to attract health workers to rural settings, understanding the expected costs and effects of the various programs ex ante can assist policy-makers in selecting the optimal incentive package. Methods: We use discrete choice experiments (DCEs), costing analyses and recent empirical results linking health worker density and health outcomes to estimate the future location decisions of physicians and determine the cost-effectiveness of 15 voluntary incentives packages for new physicians in Lao PDR. Our data sources include a DCE survey completed by medical students (n = 329) in May 2011 and secondary cost, economic and health data. Mixed logit regressions provide the basis for estimating how each incentive package influences rural versus urban location choice over time. We estimate the expected rural density of physicians and the cost-effectiveness of 15 separate incentive packages from a societal perspective. In order to generate the cost-effectiveness ratios we relied on the rural uptake probabilities inferred from the DCEs, the costing data and prior World Health Organization (WHO) estimates that relate health outcomes to health worker density. Results: Relative to no program, the optimal voluntary incentive package would increase rural physician density by 15% by 2016 and 65% by 2041. After incorporating anticipated health effects, seven (three) of the 15 incentive packages have anticipated average cost-effectiveness ratio less than the WHO threshold (three times gross domestic product [GDP] per capita) over a 5-year (30 year) period. The optimal package’s incremental cost-effectiveness ratio is $1454/QALY (quality-adjusted life year) over 5 years and $2380/QALY over 30 years. Capital intensive components, such as housing or facility improvement, are not efficient. Conclusion: Conditional on using voluntary incentives, Lao PDR should emphasize non-capital intensive options such as advanced career promotion, transport subsidies and housing allowances to improve physician distribution and rural health outcomes in a cost-effective manner. Other countries considering voluntary incentive programs can implement health worker/trainee DCEs and costing surveys to determine which incentive bundles improve rural uptake most efficiently but should be aware of methodological caveats. PMID:28812834

Flexible Packaging by Film-Assisted Molding for Microintegration of Inertia Sensors

PubMed Central

Hera, Daniel; Berndt, Armin; Günther, Thomas; Schmiel, Stephan; Harendt, Christine; Zimmermann, André

2017-01-01

Packaging represents an important part in the microintegration of sensors based on microelectromechanical system (MEMS). Besides miniaturization and integration density, functionality and reliability in combination with flexibility in packaging design at moderate costs and consequently high-mix, low-volume production are the main requirements for future solutions in packaging. This study investigates possibilities employing printed circuit board (PCB-)based assemblies to provide high flexibility for circuit designs together with film-assisted transfer molding (FAM) to package sensors. The feasibility of FAM in combination with PCB and MEMS as a packaging technology for highly sensitive inertia sensors is being demonstrated. The results prove the technology to be a viable method for damage-free packaging of stress- and pressure-sensitive MEMS. PMID:28653992

Cost-Effectiveness of Rural Incentive Packages for Graduating Medical Students in Lao PDR.

PubMed

Keuffell, Eric; Jaskiewicz, Wanda; Theppanya, Khampasong; Tulenko, Kate

2016-10-29

The dearth of health workers in rural settings in Lao People's Democratic Republic (PDR) and other developing countries limits healthcare access and outcomes. In evaluating non-wage financial incentive packages as a potential policy option to attract health workers to rural settings, understanding the expected costs and effects of the various programs ex ante can assist policy-makers in selecting the optimal incentive package. We use discrete choice experiments (DCEs), costing analyses and recent empirical results linking health worker density and health outcomes to estimate the future location decisions of physicians and determine the cost-effectiveness of 15 voluntary incentives packages for new physicians in Lao PDR. Our data sources include a DCE survey completed by medical students (n = 329) in May 2011 and secondary cost, economic and health data. Mixed logit regressions provide the basis for estimating how each incentive package influences rural versus urban location choice over time. We estimate the expected rural density of physicians and the cost-effectiveness of 15 separate incentive packages from a societal perspective. In order to generate the cost-effectiveness ratios we relied on the rural uptake probabilities inferred from the DCEs, the costing data and prior World Health Organization (WHO) estimates that relate health outcomes to health worker density. Relative to no program, the optimal voluntary incentive package would increase rural physician density by 15% by 2016 and 65% by 2041. After incorporating anticipated health effects, seven (three) of the 15 incentive packages have anticipated average cost-effectiveness ratio less than the WHO threshold (three times gross domestic product [GDP] per capita) over a 5-year (30 year) period. The optimal package's incremental cost-effectiveness ratio is $1454/QALY (quality-adjusted life year) over 5 years and $2380/QALY over 30 years. Capital intensive components, such as housing or facility improvement, are not efficient. Conditional on using voluntary incentives, Lao PDR should emphasize non-capital intensive options such as advanced career promotion, transport subsidies and housing allowances to improve physician distribution and rural health outcomes in a cost-effective manner. Other countries considering voluntary incentive programs can implement health worker/trainee DCEs and costing surveys to determine which incentive bundles improve rural uptake most efficiently but should be aware of methodological caveats. © 2017 The Author(s); Published by Kerman University of Medical Sciences. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Laser Scanner Tests For Single-Event Upsets

NASA Technical Reports Server (NTRS)

Kim, Quiesup; Soli, George A.; Schwartz, Harvey R.

1992-01-01

Microelectronic advanced laser scanner (MEALS) is opto/electro/mechanical apparatus for nondestructive testing of integrated memory circuits, logic circuits, and other microelectronic devices. Multipurpose diagnostic system used to determine ultrafast time response, leakage, latchup, and electrical overstress. Used to simulate some of effects of heavy ions accelerated to high energies to determine susceptibility of digital device to single-event upsets.

Assessing Advanced High School and Undergraduate Students' Thinking Skills: The Chemistry--From the Nanoscale to Microelectronics Module

ERIC Educational Resources Information Center

Dori, Yehudit Judy; Dangur, Vered; Avargil, Shirly; Peskin, Uri

2014-01-01

Chemistry students in Israel have two options for studying chemistry: basic or honors (advanced placement). For instruction in high school honors chemistry courses, we developed a module focusing on abstract topics in quantum mechanics: Chemistry--From the Nanoscale to Microelectronics. The module adopts a visual-conceptual approach, which…

Microelectronics in F. E.: Some Personal Perceptions. An Occasional Paper.

ERIC Educational Resources Information Center

Dean, K. J.

The recent microelectronics developments are having, and will continue to have, a sharp impact on various industries in Great Britain, and thus on the capacity of the Further Education System to produce qualified graduates. To maintain a high quality of education, instructors must learn of these new developments and teach them to their vocational…

Reliability Considerations for Ultra- Low Power Space Applications

NASA Technical Reports Server (NTRS)

White, Mark; Johnston, Allan

2012-01-01

NASA, the aerospace community, and other high reliability (hi-rel) users of advanced microelectronic products face many challenges as technology continues to scale into the deep sub- micron region and ULP devices are sought after. Technology trends, ULP microelectronics, scaling and performance tradeoffs, reliability considerations, and spacecraft environments will be presented from a ULP perspective for space applications.

Examination of SR101 shipping packages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daugherty, W. L.

Four SR101 shipping packages were removed from service and provided for disassembly and examination of the internal fiberboard assemblies. These packages were 20 years old, and had experienced varying levels of degradation. Two of the packages were successfully disassembled and fiberboard samples were removed from these packages and tested. Mechanical and thermal property values are generally comparable to or higher than baseline values measured on fiberboard from 9975 packages, which differs primarily in the specified density range. While baseline data for the SR101 material is not available, this comparison with 9975 material suggests that the material properties of the SR101more » fiberboard have not significantly degraded.« less

Novel high-density packaging of solid state diode pumped eye-safe laser for LIBS

NASA Astrophysics Data System (ADS)

Bares, Kim; Torgerson, Justin; McNeil, Laine; Maine, Patrick; Patterson, Steve

2018-02-01

Laser-Induced Breakdown Spectroscopy (LIBS) has proven to be a useful research tool for material analysis for decades. However, because of the amount of energy required in a few nanosecond pulse to generate a stable and reliable LIBS signal, the lasers are often large and inefficient, relegating their implementation to research facilities, factory floors, and assembly lines. Small portable LIBS systems are now possible without having to compromise on energy needs by leveraging off of advances in high-density packaging of electronics, opto-mechanics, and highly efficient laser resonator architecture. This paper explores the integration of these techniques to achieve a mJ class eye-safe LIBS laser source, while retaining a small, light-weight package suitable for handheld systems.

Active layers of high-performance lead zirconate titanate at temperatures compatible with silicon nano- and microelecronic devices

PubMed Central

Bretos, Iñigo; Jiménez, Ricardo; Tomczyk, Monika; Rodríguez-Castellón, Enrique; Vilarinho, Paula M.; Calzada, M. Lourdes

2016-01-01

Applications of ferroelectric materials in modern microelectronics will be greatly encouraged if the thermal incompatibility between inorganic ferroelectrics and semiconductor devices is overcome. Here, solution-processable layers of the most commercial ferroelectric compound ─ morphotrophic phase boundary lead zirconate titanate, namely Pb(Zr0.52Ti0.48)O3 (PZT) ─ are grown on silicon substrates at temperatures well below the standard CMOS process of semiconductor technology. The method, potentially transferable to a broader range of Zr:Ti ratios, is based on the addition of crystalline nanoseeds to photosensitive solutions of PZT resulting in perovskite crystallization from only 350 °C after the enhanced decomposition of metal precursors in the films by UV irradiation. A remanent polarization of 10.0 μC cm−2 is obtained for these films that is in the order of the switching charge densities demanded for FeRAM devices. Also, a dielectric constant of ~90 is measured at zero voltage which exceeds that of current single-oxide candidates for capacitance applications. The multifunctionality of the films is additionally demonstrated by their pyroelectric and piezoelectric performance. The potential integration of PZT layers at such low fabrication temperatures may redefine the concept design of classical microelectronic devices, besides allowing inorganic ferroelectrics to enter the scene of the emerging large-area, flexible electronics. PMID:26837240

Active layers of high-performance lead zirconate titanate at temperatures compatible with silicon nano- and microeletronic [corrected] devices.

PubMed

Bretos, Iñigo; Jiménez, Ricardo; Tomczyk, Monika; Rodríguez-Castellón, Enrique; Vilarinho, Paula M; Calzada, M Lourdes

2016-02-03

Applications of ferroelectric materials in modern microelectronics will be greatly encouraged if the thermal incompatibility between inorganic ferroelectrics and semiconductor devices is overcome. Here, solution-processable layers of the most commercial ferroelectric compound--morphotrophic phase boundary lead zirconate titanate, namely Pb(Zr0.52Ti0.48)O3 (PZT)--are grown on silicon substrates at temperatures well below the standard CMOS process of semiconductor technology. The method, potentially transferable to a broader range of Zr:Ti ratios, is based on the addition of crystalline nanoseeds to photosensitive solutions of PZT resulting in perovskite crystallization from only 350 °C after the enhanced decomposition of metal precursors in the films by UV irradiation. A remanent polarization of 10.0 μC cm(-2) is obtained for these films that is in the order of the switching charge densities demanded for FeRAM devices. Also, a dielectric constant of ~90 is measured at zero voltage which exceeds that of current single-oxide candidates for capacitance applications. The multifunctionality of the films is additionally demonstrated by their pyroelectric and piezoelectric performance. The potential integration of PZT layers at such low fabrication temperatures may redefine the concept design of classical microelectronic devices, besides allowing inorganic ferroelectrics to enter the scene of the emerging large-area, flexible electronics.

1/f noise measurements for faster evaluation of electromigration in advanced microelectronics interconnections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beyne, Sofie, E-mail: sofie.beyne@imec.be; De Wolf, Ingrid; imec, Kapeldreef 75, B-3001 Leuven

The use of 1/f noise measurements is explored for the purpose of finding faster techniques for electromigration (EM) characterization in advanced microelectronic interconnects, which also enable a better understanding of its underlying physical mechanisms. Three different applications of 1/f noise for EM characterization are explored. First, whether 1/f noise measurements during EM stress can serve as an early indicator of EM damage. Second, whether the current dependence of the noise power spectral density (PSD) can be used for a qualitative comparison of the defect concentration of different interconnects and consequently also their EM lifetime t50. Third, whether the activation energiesmore » obtained from the temperature dependence of the 1/f noise PSD correspond to the activation energies found by means of classic EM tests. In this paper, the 1/f noise technique has been used to assess and compare the EM properties of various advanced integration schemes and different materials, as they are being explored by the industry to enable advanced interconnect scaling. More concrete, different types of copper interconnects and one type of tungsten interconnect are compared. The 1/f noise measurements confirm the excellent electromigration properties of tungsten and demonstrate a dependence of the EM failure mechanism on copper grain size and distribution, where grain boundary diffusion is found to be a dominant failure mechanism.« less

The effect of fatigue and environment on the adhesion and delamination of thin polymer films

NASA Astrophysics Data System (ADS)

Snodgrass, Jeffrey Matthew

Polymers are increasingly used in the interconnect and packaging levels of microelectronic devices. Thus, adhesion of polymer films to their adjacent inorganic layers is critical to the manufacturability and reliability of microelectronic components. Weak interfacial adhesion can result in delamination, causing a loss of package hermeticity or the failure of electrical contacts. Recently, interface fracture mechanics techniques have been applied to the problem of thin film delamination and are now used to measure interface adhesion. These techniques allow for characterization of interface adhesion in terms of the critical strain energy release rate, GC, in units of J/m2. In this dissertation, studies are described that quantify the effects of fundamental parameters on the critical adhesion and resistance to subcritical (time-dependent) delamination of benzocyclobutene (BCB)/silica and epoxy underfill/polyimide interfaces. Results are presented detailing the action of small-molecule adhesion promoters on the critical interface adhesion energy of BCB/silica. Silane coupling agents with different functional end groups were used to increase chemical bonding at this interface in order to achieve optimized adhesion. Testing was performed at different mode mixities to evaluate the effect of loading mode on the polymer interface fracture. Subcritical debonding data were measured under two different loading conditions and results are presented in terms of the debond growth rate as a function of applied strain energy release rate. Monotonic loading was used to examine environment-assisted delamination processes, while fatigue loading was used to understand the effects of thermomechanical cycling. Debond growth rates over the range of 10-3 to 10-9 m/s were characterized under mode I and mixed-mode loading. Atomic force microscopy and X-ray photoelectron spectroscopy were used to characterize the fracture surfaces of these interfaces and to generate detailed information about the debond fracture path and mechanisms. The AFM and XPS results suggest that the failure mode of BCB/silica interfaces is cohesive in the BCB layer, in a region very close to the interface. Mechanical fatigue was found to considerably accelerate subcritical debond growth rates and decrease debond growth thresholds to as low as 25% of the critical adhesion energy. Fatigue loading produced fatigue striations on the BCB surface with a striation height of ˜1--2 nm and a spacing that was correlated with the debond growth rate. Finally, a model is presented for the mechanism of striation formation.

NASA, We Have a Challenge and It's Food Packaging

NASA Technical Reports Server (NTRS)

Perchonok, Michele

2014-01-01

Current Packaging: Freeze Dried Foods Packaging ? The thermoformed base is fabricated from Combitherm PAXX230 [a coextrusion of nylon/medium-density polyethylene (MDPE)/nylon/ethylene-vinyl alcohol (EVOH)/nylon/MDPE/linear low-density polyethylene (LLDPE)]. ? The lid is fabricated from Combitherm PAXX115 (a coextrusion of nylon/EVOH/nylon/LF adhesive/HV polyethylene/LLDPE) ? Natural form (Bite size) foods ? The bite-size food package is fabricated from Combitherm PAXX115, a coextrusion of nylon/EVOH/nylon/LF adhesive/HV polyethylene/LLDPE. ? Overwrap ? Packages are wrapped in a white pouch,.003-mm thick, fabricated from a laminate of polyester/polyethylene/aluminum foil/Surlyn®. This overwrap is removed before the food is prepared and heated. Requirements ? High barrier packaging - low oxygen and water vapor transmission rates ? No aluminum layer ? Mass - <145 grams per m2 ? Flexible ? Puncture resistant ? Approved for food use ? Amenable to sterilization ? Able to be heat sealed ? Preferred (not required) ? Transparent ? Retortable, microwavable, high pressure use. Small Business Innovative Research Program - 7 years ? 8 Phase I contracts ? 4 Phase II contracts ? Two workshops to bring together food packaging experts ? Three internal research tasks ? Public Outreach - average of 3 presentations/yr. for 8 years describing NASA's challenges ? Department of Defense Collaboration - Combat Feeding Program No significant improvement in food packaging capabilities after these efforts. It was unlikely that a food packaging solution could be found within the food science community ? There was a need to go outside to other industries such as pharmaceutical or electrical ? Although a positive result was preferred, a negative result would also be useful ? Two Innovation Techniques were used as a comparison ? InnoCentive - Theoretical Challenge to identify new technologies ? Yet2.com - A matchmaker between NASA and commercial packaging manufacturers

A longitudinal analysis of alcohol outlet density and domestic violence.

PubMed

Livingston, Michael

2011-05-01

A small number of studies have identified a positive relationship between alcohol outlet density and domestic violence. These studies have all been based on cross-sectional data and have been limited to the assessment of ecological correlations between outlet density and domestic violence rates. This study provides the first longitudinal examination of this relationship. Cross-sectional time-series using aggregated data from small areas. The relationships between alcohol outlet density and domestic violence were assessed over time using a fixed-effects model. Controls for the spatial autocorrelation of the data were included in the model. The study uses data for 186 postcodes from within the metropolitan area of Melbourne, Australia for the years 1996 to 2005. Alcohol outlet density measures for three different types of outlets (hotel/pub, packaged liquor, on-premise) were derived from liquor licensing records and domestic violence rates were calculated from police-recorded crime data, based on the victim's postcode. Alcohol outlet density was associated significantly with rates of domestic violence, over time. All three licence categories were positively associated with domestic violence rates, with small effects for general (pub) and on-premise licences and a large effect for packaged liquor licences. In Melbourne, the density of liquor licences is positively associated with rates of domestic violence over time. The effects were particularly large for packaged liquor outlets, suggesting a need for licensing policies that pay more attention to o off-premise alcohol availability. © 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.

An ab-initio study of mechanical, dynamical and electronic properties of MgEu intermetallic

NASA Astrophysics Data System (ADS)

Kumar, S. Ramesh; Jaiganesh, G.; Jayalakshmi, V.

2018-04-01

The theoretical investigation on the mechanical, dynamical and electronic properties of MgEu in CsCl-type structure has been carried out through the ab-initio calculations within the framework of the density functional theory and the density functional perturbation theory. For the purpose, Vienna Ab initio Simulation Package and Phonopy packages were used. Our calculated ground-state properties of MgEu are in good agreement with other available results. Our computed elastic constants and phonon spectrum results suggest that MgEu is mechanically and dynamically stable up to 5 GPa. The thermodynamic quantities as a function of temperatures are also reported and discussed. The band structure, density of states and charge density also calculated to understand the electronic properties of MgEu.

The Impact of Dopant Segregation on the Maximum Carrier Density in Si:P Multilayers.

PubMed

Keizer, Joris G; McKibbin, Sarah R; Simmons, Michelle Y

2015-07-28

Abrupt dopant profiles and low resistivity are highly sought after qualities in the silicon microelectronics industry and, more recently, in the development of an all epitaxial Si:P based quantum computer. If we increase the active carrier density in silicon to the point where the material becomes superconducting, while maintaining a low thermal budget, it will be possible to fabricate nanoscale superconducting devices using the highly successful technique of depassivation lithography. In this work, we investigate the dopant profile and activation in multiple high density Si:P δ-layers fabricated by stacking individual layers with intervening silicon growth. We determine that dopant activation is ultimately limited by the formation of P-P dimers due to the segregation of dopants between multilayers. By increasing the encapsulation thickness between subsequent layers, thereby minimizing the formation of these deactivating defects, we are able to achieve an active carrier density of ns = 4.5 ×10(14) cm(-2) for a triple layer. The results of electrical characterization are combined with those of secondary ion mass spectroscopy to construct a model that accurately describes the impact of P segregation on the final active carrier density in Si:P multilayers. Our model predicts that a 3D active carrier density of 8.5 × 10(20) cm(-3) (1.7 atom %) can be achieved.

Uses of ceramics in microelectronics: A survey

NASA Technical Reports Server (NTRS)

Bratschun, W. R.; Mountvala, A. J.; Pincus, A. G.

1971-01-01

The properties and behavior of ceramic materials used in components for electronic circuitry are examined to appraise the present and future directions for microelectronics, and to suggest further product development, and how innovations may be useful in other technologies. Ceramic and glass insulators, resistors, capacitors, and the use of ceramics and glasses in microcircuitry are discussed along with technology transfer to nonaerospace uses.

Investigation of “benign” ionic content in epoxy that induces microelectronic device failure

Treesearch

Gregory T. Schueneman; Jeffery Kingsbury; Edmund Klinkerch

2011-01-01

Microelectronics and the devices dependent upon them have the extremely challenging requirements of becoming more capable and less expensive every year. This drives the industry to pack more functions into an ever smaller footprint until the next technological revolution. Adding to this situation is the removal of lead from the bill of materials followed closely by...

Microelectronics used for Semiconductor Imaging Detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heijne, Erik H. M.

Semiconductor crystal technology, microelectronics developments and nuclear particle detection have been in a relation of symbiosis, all the way from the beginning. The increase of complexity in electronics chips can now be applied to obtain much more information on the incident nuclear radiation. Some basic technologies are described, in order to acquire insight in possibilities and limitations for the most recent detectors.

Validation of Direct Analysis Real Time source/Time-of-Flight Mass Spectrometry for organophosphate quantitation on wafer surface.

PubMed

Hayeck, Nathalie; Ravier, Sylvain; Gemayel, Rachel; Gligorovski, Sasho; Poulet, Irène; Maalouly, Jacqueline; Wortham, Henri

2015-11-01

Microelectronic wafers are exposed to airborne molecular contamination (AMC) during the fabrication process of microelectronic components. The organophosphate compounds belonging to the dopant group are one of the most harmful groups. Once adsorbed on the wafer surface these compounds hardly desorb and could diffuse in the bulk of the wafer and invert the wafer from p-type to n-type. The presence of these compounds on wafer surface could have electrical effect on the microelectronic components. For these reasons, it is of importance to control the amount of these compounds on the surface of the wafer. As a result, a fast quantitative and qualitative analytical method, nondestructive for the wafers, is needed to be able to adjust the process and avoid the loss of an important quantity of processed wafers due to the contamination by organophosphate compounds. Here we developed and validated an analytical method for the determination of organic compounds adsorbed on the surface of microelectronic wafers using the Direct Analysis in Real Time-Time of Flight-Mass Spectrometry (DART-ToF-MS) system. Specifically, the developed methodology concerns the organophosphate group. Copyright © 2015 Elsevier B.V. All rights reserved.

European MEMS foundries

NASA Astrophysics Data System (ADS)

Salomon, Patric R.

2003-01-01

According to the latest release of the NEXUS market study, the market for MEMS or Microsystems Technology (MST) is predicted to grow to $68B by the year 2005, with systems containing these components generating even higher revenues and growth. The latest advances in MST/MEMS technology have enabled the design of a new generation of microsystems that are smaller, cheaper, more reliable, and consume less power. These integrated systems bring together numerous analog/mixed signal microelectronics blocks and MEMS functions on a single chip or on two or more chips assembled within an integrated package. In spite of all these advances in technology and manufacturing, a system manufacturer either faces a substantial up-front R&D investment to create his own infrastructure and expertise, or he can use design and foundry services to get the initial product into the marketplace fast and with an affordable investment. Once he has a viable product, he can still think about his own manufacturing efforts and investments to obtain an optimized high volume manufacturing for the specific product. One of the barriers to successful exploitation of MEMS/MST technology has been the lack of access to industrial foundries capable of producing certified microsystems devices in commercial quantities, including packaging and test. This paper discusses Multi-project wafer (MPW) runs, requirements for foundries and gives some examples of foundry business models. Furthermore, this paper will give an overview on MST/MEMS services that are available in Europe, including pure commercial activities, European project activities (e.g. Europractice), and some academic services.

An ultra-compact processor module based on the R3000

NASA Astrophysics Data System (ADS)

Mullenhoff, D. J.; Kaschmitter, J. L.; Lyke, J. C.; Forman, G. A.

1992-08-01

Viable high density packaging is of critical importance for future military systems, particularly space borne systems which require minimum weight and size and high mechanical integrity. A leading, emerging technology for high density packaging is multi-chip modules (MCM). During the 1980's, a number of different MCM technologies have emerged. In support of Strategic Defense Initiative Organization (SDIO) programs, Lawrence Livermore National Laboratory (LLNL) has developed, utilized, and evaluated several different MCM technologies. Prior LLNL efforts include modules developed in 1986, using hybrid wafer scale packaging, which are still operational in an Air Force satellite mission. More recent efforts have included very high density cache memory modules, developed using laser pantography. As part of the demonstration effort, LLNL and Phillips Laboratory began collaborating in 1990 in the Phase 3 Multi-Chip Module (MCM) technology demonstration project. The goal of this program was to demonstrate the feasibility of General Electric's (GE) High Density Interconnect (HDI) MCM technology. The design chosen for this demonstration was the processor core for a MIPS R3000 based reduced instruction set computer (RISC), which has been described previously. It consists of the R3000 microprocessor, R3010 floating point coprocessor and 128 Kbytes of cache memory.

Reliability and Characteristics of Wafer-Level Chip-Scale Packages under Current Stress

NASA Astrophysics Data System (ADS)

Chen, Po-Ying; Kung, Heng-Yu; Lai, Yi-Shao; Hsiung Tsai, Ming; Yeh, Wen-Kuan

2008-02-01

In this work, we present a novel approach and method for elucidating the characteristics of wafer-level chip-scale packages (WLCSPs) for electromigration (EM) tests. The die in WLCSP was directly attached to the substrate via a soldered interconnect. The shrinking of the area of the die that is available for power, and the solder bump also shrinks the volume and increases the density of electrons for interconnect efficiency. The bump current density now approaches to 106 A/cm2, at which point the EM becomes a significant reliability issue. As known, the EM failure depends on numerous factors, including the working temperature and the under bump metallization (UBM) thickness. A new interconnection geometry is adopted extensively with moderate success in overcoming larger mismatches between the displacements of components during current and temperature changes. Both environments and testing parameters for WLCSP are increasingly demanded. Although failure mechanisms are considered to have been eliminated or at least made manageable, new package technologies are again challenging its process, integrity and reliability. WLCSP technology was developed to eliminate the need for encapsulation to ensure compatibility with smart-mount technology (SMT). The package has good handing properties but is now facing serious reliability problems. In this work, we investigated the reliability of a WLCSP subjected to different accelerated current stressing conditions at a fixed ambient temperature of 125 °C. A very strong correlation exists between the mean time to failure (MTTF) of the WLCSP test vehicle and the mean current density that is carried by a solder joint. A series of current densities were applied to the WLCSP architecture; Black's power law was employed in a failure mode simulation. Additionally, scanning electron microscopy (SEM) was adopted to determine the differences existing between high- and low-current-density failure modes.

Cluster-lensing: A Python Package for Galaxy Clusters and Miscentering

NASA Astrophysics Data System (ADS)

Ford, Jes; VanderPlas, Jake

2016-12-01

We describe a new open source package for calculating properties of galaxy clusters, including Navarro, Frenk, and White halo profiles with and without the effects of cluster miscentering. This pure-Python package, cluster-lensing, provides well-documented and easy-to-use classes and functions for calculating cluster scaling relations, including mass-richness and mass-concentration relations from the literature, as well as the surface mass density {{Σ }}(R) and differential surface mass density {{Δ }}{{Σ }}(R) profiles, probed by weak lensing magnification and shear. Galaxy cluster miscentering is especially a concern for stacked weak lensing shear studies of galaxy clusters, where offsets between the assumed and the true underlying matter distribution can lead to a significant bias in the mass estimates if not accounted for. This software has been developed and released in a public GitHub repository, and is licensed under the permissive MIT license. The cluster-lensing package is archived on Zenodo. Full documentation, source code, and installation instructions are available at http://jesford.github.io/cluster-lensing/.

Optimal segmentation and packaging process

DOEpatents

Kostelnik, Kevin M.; Meservey, Richard H.; Landon, Mark D.

1999-01-01

A process for improving packaging efficiency uses three dimensional, computer simulated models with various optimization algorithms to determine the optimal segmentation process and packaging configurations based on constraints including container limitations. The present invention is applied to a process for decontaminating, decommissioning (D&D), and remediating a nuclear facility involving the segmentation and packaging of contaminated items in waste containers in order to minimize the number of cuts, maximize packaging density, and reduce worker radiation exposure. A three-dimensional, computer simulated, facility model of the contaminated items are created. The contaminated items are differentiated. The optimal location, orientation and sequence of the segmentation and packaging of the contaminated items is determined using the simulated model, the algorithms, and various constraints including container limitations. The cut locations and orientations are transposed to the simulated model. The contaminated items are actually segmented and packaged. The segmentation and packaging may be simulated beforehand. In addition, the contaminated items may be cataloged and recorded.

Robust, Rework-able Thermal Electronic Packaging: Applications in High Power TR Modules for Space

NASA Technical Reports Server (NTRS)

Hoffman, James Patrick; Del Castillo, Linda; Hunter, Don; Miller, Jennifer

2012-01-01

The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires improvements in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and are now being implemented side-by-side with more standard technology typically used in flight hardware.

Microelectronics Reliability

DTIC Science & Technology

2017-01-17

2016-0155 Kirtland AFB, NM 87117-5776 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) AFRL /RVSW 11...22060-6218 1 cy AFRL /RVIL Kirtland AFB, NM 87117-5776 2 cys Official Record Copy AFRL /RVSW/Clay Mayberry 1 cy Approved for... AFRL -RV-PS- AFRL -RV-PS- TR-2016-0155 TR-2016-0155 MICROELECTRONICS RELIABILITY Clay Mayberry and Joseph Bernstein 17 Jan 2017 Interim Report

Microelectronic bioinstrumentation system

NASA Technical Reports Server (NTRS)

Ko, W. H.; Yon, E. T.; Rodriguez, R. J.

1974-01-01

The progess made from April 1973 to June 1974 on a microelectronics bioinstrumentation system is reported and includes data for the following three individual projects: (1) a radio frequency powered implant telemetry system; (2) an ingestible temperature telemeter; and (3) development of pO2 and pH sensors. Proposed activities for continuation of the research for the period September 1, 1974 to August 31, 1975 are also discussed.

Radiofrequency and microwave radiation in the microelectronics industry.

PubMed

Cohen, R

1986-01-01

The microscopic precision required to produce minute integrated circuits is dependent on several processes utilizing radiofrequency and microwave radiation. This article provides a review of radiofrequency and microwave exposures in microelectronics and of the physical and biologic properties of these types of radiation; summarizes the existing, relevant medical literature; and provides the clinician with guidelines for diagnosis and treatment of excessive exposures to microwave and radiofrequency radiation.

Photopolymerizable liquid encapsulants for microelectronic devices

NASA Astrophysics Data System (ADS)

Baikerikar, Kiran K.

2000-10-01

Plastic encapsulated microelectronic devices consist of a silicon chip that is physically attached to a leadframe, electrically interconnected to input-output leads, and molded in a plastic that is in direct contact with the chip, leadframe, and interconnects. The plastic is often referred to as the molding compound, and is used to protect the chip from adverse mechanical, thermal, chemical, and electrical environments. Encapsulation of microelectronic devices is typically accomplished using a transfer molding process in which the molding compound is cured by heat. Most transfer molding processes suffer from significant problems arising from the high operating temperatures and pressures required to fill the mold. These aspects of the current process can lead to thermal stresses, incomplete mold filling, and wire sweep. In this research, a new strategy for encapsulating microelectronic devices using photopolymerizable liquid encapsulants (PLEs) has been investigated. The PLEs consist of an epoxy novolac-based vinyl ester resin (˜25 wt.%), fused silica filler (70--74 wt.%), and a photoinitiator, thermal initiator, and silane coupling agent. For these encapsulants, the use of light, rather than heat, to initiate the polymerization allows precise control over when the reaction starts, and therefore completely decouples the mold filling and the cure. The low viscosity of the PLEs allows for low operating pressures and minimizes problems associated with wire sweep. In addition, the in-mold cure time for the PLEs is equivalent to the in-mold cure times of current transfer molding compounds. In this thesis, the thermal and mechanical properties, as well as the viscosity and adhesion of photopolymerizable liquid encapsulants, are reported in order to demonstrate that a UV-curable formulation can have the material properties necessary for microelectronic encapsulation. In addition, the effects of the illumination time, postcure time, fused silica loading, and the inclusion of a thermal initiator on the thermal and mechanical properties of the final cured encapsulants have been investigated. The results show that the material properties of the PLEs are the same, if not better, than those exhibited by conventional transfer molding compounds and demonstrate the potential of using PLEs for encapsulating microelectronic devices.

Research Activities at Plasma Research Laboratory at NASA Ames Research Center

NASA Technical Reports Server (NTRS)

Sharma, S. P.; Rao, M. V. V. S.; Meyyappan, Meyya

2000-01-01

In order to meet NASA's requirements for the rapid development and validation of future generation electronic devices as well as associated materials and processes, enabling technologies are being developed at NASA-Ames Research Center using a multi-discipline approach. The first step is to understand the basic physics of the chemical reactions in the area of plasma reactors and processes. Low pressure glow discharges are indispensable in the fabrication of microelectronic circuits. These plasmas are used to deposit materials and also etch fine features in device fabrication. However, many plasma-based processes suffer from stability and reliability problems leading to a compromise in performance and a potentially increased cost for the semiconductor manufacturing industry. Although a great deal of laboratory-scale research has been performed on many of these processing plasmas, little is known about the gas-phase and surface chemical reactions that are critical in many etch and deposition processes, and how these reactions are influenced by the variation in operating conditions. Such a lack of understanding has hindered the development of process models that can aid in the scaling and improvement of plasma etch and deposition systems. Our present research involves the study of such plasmas. An inductively-coupled plasma (ICP) source in place of the standard upper electrode assembly of the Gaseous Electronics Conference (GEC) radio-frequency (RF) Reference Cell is used to investigate the discharge characteristics. This ICP source generates plasmas with higher electron densities and lower operating pressures than obtainable with the original parallel-plate version of the GEC Cell. This expanded operating regime is more relevant to new generations of industrial plasma systems being used by the microelectronics industry. The research goal is to develop an understanding of the physical phenomena involved in plasma processing and to measure much needed fundamental parameters, such as gas phase and surface reaction rates, species concentration, temperature, ion energy distribution, and electron number density.

Role of field-induced nanostructures, zippering and size polydispersity on effective thermal transport in magnetic fluids without significant viscosity enhancement

NASA Astrophysics Data System (ADS)

Vinod, Sithara; Philip, John

2017-12-01

Magnetic nanofluids or ferrofluids exhibit extraordinary field dependant tunable thermal conductivity (k), which make them potential candidates for microelectronic cooling applications. However, the associated viscosity enhancement under an external stimulus is undesirable for practical applications. Further, the exact mechanism of heat transport and the role of field induced nanostructures on thermal transport is not clearly understood. In this paper, through systematic thermal, rheological and microscopic studies in 'model ferrofluids', we demonstrate for the first time, the conditions to achieve very high thermal conductivity to viscosity ratio. Highly stable ferrofluids with similar crystallite size, base fluid, capping agent and magnetic properties, but with slightly different size distributions, are synthesized and characterized by X-ray diffraction, small angle X-ray scattering, transmission electron microscopy, dynamic light scattering, vibrating sample magnetometer, Fourier transform infrared spectroscopy and thermo-gravimetry. The average hydrodynamic diameters of the particles were 11.7 and 10.1 nm and the polydispersity indices (σ), were 0.226 and 0.151, respectively. We observe that the system with smaller polydispersity (σ = 0.151) gives larger k enhancement (130% for 150 G) as compared to the one with σ = 0.226 (73% for 80 G). Further, our results show that dispersions without larger aggregates and with high density interfacial capping (with surfactant) can provide very high enhancement in thermal conductivity, with insignificant viscosity enhancement, due to minimal interfacial losses. We also provide experimental evidence for the effective heat conduction (parallel mode) through a large number of space filling linear aggregates with high aspect ratio. Microscopic studies reveal that the larger particles act as nucleating sites and facilitate lateral aggregation (zippering) of linear chains that considerably reduces the number density of space filling linear aggregates. Our findings are very useful for optimizing the heat transfer properties of magnetic fluids (and also in composite systems consisting of CNT, graphene etc.) for the development of next generation microelectronic cooling technologies, thermal energy harvesting and magnetic fluid based therapeutics.

Controlling microstructure and mechanical properties of the new microelectronic interconnect alloys

NASA Astrophysics Data System (ADS)

Mutuku, Francis M.

An in-depth understanding of the physics of solidification could lead to the optimization of the properties of micro-electronic interconnects. Sn is the base material in the billions of interconnects in devices such as smart phones. These interconnects are formed by melting and solidifying a solder alloy (e.g. SnAgCu) in situ. But Sn has a low symmetry structure, Sn nucleation from the solder melt is complex and the morphology of the Sn and Sn alloys precipitates that form during solidification can vary tremendously (along with resultant mechanical properties). The effect of processing parameters on the solidification behavior, microstructure, and properties must be carefully addressed. Strong evidence adduced in this study shows that under many conditions, when cooling near eutectic SnAgCu from the melt, Ag3Sn nucleates before beta-Sn. The difficulty in the nucleation of beta-Sn provides a window of time between the nucleation of Ag3Sn precipitates and of beta-Sn solidification within which the Ag3Sn precipitate morphology can be manipulated. Thus distinct variations in precipitate number density, and inter-particle spacing were observed for different thermal histories, e.g. for different cooling rates. The average number density of Ag3Sn particles and the area of the pseudo-eutectic phase were observed to increase with increase in the Ag concentration, and with increase in the cooling rate. The shear strength and shear fatigue life increased with increase in the area fraction of the pseudo-eutectic phase. Upon aging of SnAgCu solder joints at an elevated temperature, the Ag3Sn particles coarsened, and became less effective in impeding dislocation motion. Consequently, the shear strength and shear fatigue performance degraded. On the other hand, alloys with constituents that formed solid solutions in Sn, such as small concentrations of Bi or Sb registered less degradation in both shear strength and shear fatigue life upon aging.

Microsensor research

NASA Astrophysics Data System (ADS)

Hughes, R. C.; Drebing, C. G.

1990-04-01

The technology that led to very large scale integrated circuits on silicon chips also provides a basis for new microsensors that are small, inexpensive, low power, rugged, and reliable. Two examples of microsensors Sandia is developing that take advantage of this technology are the microelectronic chemical sensor array and the radiation sensing field effect transistor (RADFET). Increasingly, the technology of chemical sensing needs new microsensor concepts. Applications in this area include environmental monitoring, criminal investigations, and state-of-health monitoring, both for equipment and living things. Chemical microsensors can satisfy sensing needs in the industrial, consumer, aerospace, and defense sectors. The microelectronic chemical-sensor array may address some of these applications. We have fabricated six separate chemical gas sensing areas on the microelectronic chemical sensor array. By using different catalytic metals on the gate areas of the diodes, we can selectively sense several gases.

Applicability of LET to single events in microelectronic structures

NASA Astrophysics Data System (ADS)

Xapsos, Michael A.

1992-12-01

LET is often used as a single parameter to determine the energy deposited in a microelectronic structure by a single event. The accuracy of this assumption is examined for ranges of ion energies and volumes of silicon appropriate for modern microelectronics. It is shown to be accurate only under very restricted conditions. Significant differences arise because (1) LET is related to energy lost by the ion, not energy deposited in the volume; and (2) LET is an average value and does not account for statistical variations in energy deposition. Criteria are suggested for determining when factors other than LET should be considered, and new analytical approaches are presented to account for them. One implication of these results is that improvements can be made in space upset rate predictions by incorporating the new methods into currently used codes such as CREME and CRUP.

49 CFR 173.316 - Cryogenic liquids in cylinders.

Code of Federal Regulations, 2011 CFR

2011-10-01

... filling density for hydrogen, cryogenic liquid is defined as the percent ratio of the weight of lading in... 49 Transportation 2 2011-10-01 2011-10-01 false Cryogenic liquids in cylinders. 173.316 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.316 Cryogenic liquids in...

Physical and Thermal Structure of the Bishop Tuff, California

NASA Astrophysics Data System (ADS)

Wilson, C. J.; Hildreth, W.

2001-12-01

The 0.76 Ma Bishop Tuff, California, includes an ignimbrite constructed from a series of overlapping packages of material erupted sequentially and simultaneously from multiple sources around the ring fracture of Long Valley caldera (Wilson, C.J.N., Hildreth, W., 1997, Journal of Geology 105, 407-439). Exceptionally good continuous exposures of the ignimbrite in the walls of Owens Gorge to the east of Long Valley provide a cross-section through the east-side packages (Ig1E and Ig2E). We have measured 10 sections up the gorge walls to draw up a cross section of the ignimbrite down Owens Gorge, using lithic abundances and lithologies to define the physical eruptive packages and their subdivisions, and measurements of tuff bulk density (as an easily measured proxy for welding intensity) to define the thermal eruptive packages. The physically emplaced bodies of ignimbrite represent an overlapping, shingling suite of material such that successively later ignimbrite occurs most prominently farther away from source. Two major and two lesser zones of maximum density (welding) are present, the lower two (in Ig1Ea and lower Ig1Eb) in upper Owens Gorge, and the two most prominent (upper Ig1Eb and Ig2Eb) in middle and lower parts of the gorge. Welding fluctuations are controlled by bulk temperatures of individual batches of hotter and cooler material, but the intensity of the welding also depends on deposit thickness (i.e. load stress). Physically defined contacts between ignimbrite packages show that time breaks inferred to be of hours may not result in formation of any visible parting or flow unit boundary. Furthermore, positions of density (welding) minima between zones of higher density tuff do not coincide with horizons of stratigraphic significance. These observations lead to two conclusions. (1) The absence of clear partings or flow unit boundaries in an ignimbrite sequence is not diagnostic either of the material representing a single flow unit, or of the material being continuously progressively aggraded. (2) Use of the density (welding) minimum to locate the boundaries of cooling units and in measuring and modelling the emplacement and thermal history of compound cooling units may lead to errors.

Majority logic gate for 3D magnetic computing.

PubMed

Eichwald, Irina; Breitkreutz, Stephan; Ziemys, Grazvydas; Csaba, György; Porod, Wolfgang; Becherer, Markus

2014-08-22

For decades now, microelectronic circuits have been exclusively built from transistors. An alternative way is to use nano-scaled magnets for the realization of digital circuits. This technology, known as nanomagnetic logic (NML), may offer significant improvements in terms of power consumption and integration densities. Further advantages of NML are: non-volatility, radiation hardness, and operation at room temperature. Recent research focuses on the three-dimensional (3D) integration of nanomagnets. Here we show, for the first time, a 3D programmable magnetic logic gate. Its computing operation is based on physically field-interacting nanometer-scaled magnets arranged in a 3D manner. The magnets possess a bistable magnetization state representing the Boolean logic states '0' and '1.' Magneto-optical and magnetic force microscopy measurements prove the correct operation of the gate over many computing cycles. Furthermore, micromagnetic simulations confirm the correct functionality of the gate even for a size in the nanometer-domain. The presented device demonstrates the potential of NML for three-dimensional digital computing, enabling the highest integration densities.

Ultracompliant Heterogeneous Copper-Tin Nanowire Arrays Making a Supersolder.

PubMed

Gong, Wei; Li, Pengfei; Zhang, Yunheng; Feng, Xuhui; Major, Joshua; DeVoto, Douglas; Paret, Paul; King, Charles; Narumanchi, Sreekant; Shen, Sheng

2018-06-13

Due to the substantial increase in power density, thermal interface resistance that can constitute more than 50% of the total thermal resistance has generally become a bottleneck for thermal management in electronics. However, conventional thermal interface materials (TIMs) such as solder, epoxy, gel, and grease cannot fulfill the requirements of electronics for high-power and long-term operation. Here, we demonstrate a high-performance TIM consisting of a heterogeneous copper-tin nanowire array, which we term "supersolder" to emulate the role of conventional solders in bonding various surfaces. The supersolder is ultracompliant with a shear modulus 2-3 orders of magnitude lower than traditional solders and can reduce the thermal resistance by two times as compared with the state-of-the-art TIMs. This supersolder also exhibits excellent long-term reliability with >1200 thermal cycles over a wide temperature range. By resolving this critical thermal bottleneck, the supersolder enables electronic systems, ranging from microelectronics and portable electronics to massive data centers, to operate at lower temperatures with higher power density and reliability.

39 CFR Appendix A to Subpart A of... - Mail Classification Schedule

Code of Federal Regulations, 2012 CFR

2012-07-01

... Density and Saturation Letters High Density and Saturation Flats/Parcels Carrier Route Letters Flats Not... Package Services Single-Piece Parcel Post Inbound Surface Parcel Post (at UPU rates) Bound Printed Matter... Single-Piece First-Class Mail International Standard Mail (Regular and Nonprofit) High Density and...

Strategic Computing. New-Generation Computing Technology: A Strategic Plan for Its Development and Application to Critical Problems in Defense

DTIC Science & Technology

1983-10-28

Computing. By seizing an opportunity to leverage recent advances in artificial intelligence, computer science, and microelectronics, the Agency plans...occurred in many separated areas of artificial intelligence, computer science, and microelectronics. Advances in "expert system" technology now...and expert knowledge o Advances in Artificial Intelligence: Mechanization of speech recognition, vision, and natural language understanding. o

Using FLUKA to Calculate Spacecraft: Single Event Environments: A Practical Approach

NASA Technical Reports Server (NTRS)

Koontz, Steve; Boeder, Paul; Reddell, Brandon

2009-01-01

The FLUKA nuclear transport and reaction code can be developed into a practical tool for calculation of spacecraft and planetary surface asset SEE and TID environments. Nuclear reactions and secondary particle shower effects can be estimated with acceptable accuracy both in-flight and in test. More detailed electronic device and/or spacecraft geometries than are reported here are possible using standard FLUKA geometry utilities. Spacecraft structure and shielding mass. Effects of high Z elements in microelectronic structure as reported previously. Median shielding mass in a generic slab or concentric sphere target geometry are at least approximately applicable to more complex spacecraft shapes. Need the spacecraft shielding mass distribution function applicable to the microelectronic system of interest. SEE environment effects can be calculated for a wide range of spacecraft and microelectronic materials with complete nuclear physics. Evaluate benefits of low Z shielding mass can be evaluated relative to aluminum. Evaluate effects of high Z elements as constituents of microelectronic devices. The principal limitation on the accuracy of the FLUKA based method reported here are found in the limited accuracy and incomplete character of affordable heavy ion test data. To support accurate rate estimates with any calculation method, the aspect ratio of the sensitive volume(s) and the dependence must be better characterized.

PREFACE: The Second Conference on Microelectronics, Microsystems and Nanotechnology

NASA Astrophysics Data System (ADS)

Nassiopoulou, Androula G.; Papanikolaou, Nikos; Tsamis, Christos

2005-01-01

The Second Conference on Microelectronics, Microsystems and Nanotechnology took place at the National Centre for Scientific Research `Demokritos', in Athens, Greece, between 14 and 17 November 2004. The conference was organized by the Institute of Microelectronics (IMEL) with the aim to bring together scientists and engineers working in the above exciting fields in an interactive forum. The conference included 45 oral presentations with 9 invited papers and was attended by 146 participants from 16 countries. The topics covered were nanotechnologies, quantum devices, sensors, micro- and nano-systems, semiconductor devices, C-MOS fabrication and characterization techniques, new materials, and IC design. Quantum devices and nanostructured materials attracted considerable attention. Both theoretical and experimental studies of metallic and semiconducting quantum systems were presented, with emphasis on their applications in electronics, optoelectronics, and nanocrystal memory devices. Another exciting topic was the recent developments in biocompatible lithographic processes for applications in biosensors. In particular novel processes for bio-friendly lithography, together with innovations in Si sensors for applications in medicine and food industry were presented. Recent developments and perspectives in CMOS technology towards the ultimate limit were also discussed. The conference covered issues and concepts of IC design with two invited talks on RF design and cryptography.The conference included presentations from several companies active in the field of microelectronics and systems in Greece.

SEAWAT Version 4: A Computer Program for Simulation of Multi-Species Solute and Heat Transport

USGS Publications Warehouse

Langevin, Christian D.; Thorne, Daniel T.; Dausman, Alyssa M.; Sukop, Michael C.; Guo, Weixing

2008-01-01

The SEAWAT program is a coupled version of MODFLOW and MT3DMS designed to simulate three-dimensional, variable-density, saturated ground-water flow. Flexible equations were added to the program to allow fluid density to be calculated as a function of one or more MT3DMS species. Fluid density may also be calculated as a function of fluid pressure. The effect of fluid viscosity variations on ground-water flow was included as an option. Fluid viscosity can be calculated as a function of one or more MT3DMS species, and the program includes additional functions for representing the dependence on temperature. Although MT3DMS and SEAWAT are not explicitly designed to simulate heat transport, temperature can be simulated as one of the species by entering appropriate transport coefficients. For example, the process of heat conduction is mathematically analogous to Fickian diffusion. Heat conduction can be represented in SEAWAT by assigning a thermal diffusivity for the temperature species (instead of a molecular diffusion coefficient for a solute species). Heat exchange with the solid matrix can be treated in a similar manner by using the mathematically equivalent process of solute sorption. By combining flexible equations for fluid density and viscosity with multi-species transport, SEAWAT Version 4 represents variable-density ground-water flow coupled with multi-species solute and heat transport. SEAWAT Version 4 is based on MODFLOW-2000 and MT3DMS and retains all of the functionality of SEAWAT-2000. SEAWAT Version 4 also supports new simulation options for coupling flow and transport, and for representing constant-head boundaries. In previous versions of SEAWAT, the flow equation was solved for every transport timestep, regardless of whether or not there was a large change in fluid density. A new option was implemented in SEAWAT Version 4 that allows users to control how often the flow field is updated. New options were also implemented for representing constant-head boundaries with the Time-Variant Constant-Head (CHD) Package. These options allow for increased flexibility when using CHD flow boundaries with the zero-dispersive flux solute boundaries implemented by MT3DMS at constant-head cells. This report contains revised input instructions for the MT3DMS Dispersion (DSP) Package, Variable-Density Flow (VDF) Package, Viscosity (VSC) Package, and CHD Package. The report concludes with seven cases of an example problem designed to highlight many of the new features.

Thick resist for MEMS processing

NASA Astrophysics Data System (ADS)

Brown, Joe; Hamel, Clifford

2001-11-01

The need for technical innovation is always present in today's economy. Microfabrication methods have evolved in support of the demand for smaller and faster integrated circuits with price performance improvements always in the scope of the manufacturing design engineer. The dispersion of processing technology spans well beyond IC fabrication today with batch fabrication and wafer scale processing lending advantages to MEMES applications from biotechnology to consumer electronics from oil exploration to aerospace. Today the demand for innovative processing techniques that enable technology is apparent where only a few years ago appeared too costly or not reliable. In high volume applications where yield and cost improvements are measured in fractions of a percent it is imperative to have process technologies that produce consistent results. Only a few years ago thick resist coatings were limited to thickness less than 20 microns. Factors such as uniformity, edge bead and multiple coatings made high volume production impossible. New developments in photoresist formulation combined with advanced coating equipment techniques that closely controls process parameters have enable thick photoresist coatings of 70 microns with acceptable uniformity and edge bead in one pass. Packaging of microelectronic and micromechanical devices is often a significant cost factor and a reliability issue for high volume low cost production. Technologies such as flip- chip assembly provide a solution for cost and reliability improvements over wire bond techniques. The processing for such technology demands dimensional control and presents a significant cost savings if it were compatible with mainstream technologies. Thick photoresist layers, with good sidewall control would allow wafer-bumping technologies to penetrate the barriers to yield and production where costs for technology are the overriding issue. Single pass processing is paramount to the manufacturability of packaging technology. Uniformity and edge bead control defined the success of process implementation. Today advanced packaging solutions are created with thick photoresist coatings. The techniques and results will be presented.

Organo-metallic elements for associative information processing

NASA Astrophysics Data System (ADS)

Potember, Richard S.; Poehler, Theodore O.

1989-01-01

In the three years of the program we have: (1) built and tested a 4 bit element matrix device for possible use in high density content-addressable memories systems; (2) established a test and evaluation laboratory to examine optical materials for nonlinear effects, saturable absorption, harmonic generation and photochromism; (3) successfully designed, constructed and operated a codeposition processing system that enables organic materials to be deposited on a variety of substrates to produce optical grade coatings and films. This system is also compatible with other traditional microelectronic techniques; (4) used the sol-gel process with colloidal AgTCNQ to fabricate high speed photochromic switches; (5) develop and applied for patent coverage to make VO2 optical switching materials via the sol-gel processing using vanadium (IV) alkoxide compounds.

Shuttle high resolution accelerometer package experiment results - Atmospheric density measurements between 60-160 km

NASA Technical Reports Server (NTRS)

Blanchard, R. C.; Hinson, E. W.; Nicholson, J. Y.

1988-01-01

Indirect or inferred values of atmospheric density encountered by the Shuttle Orbiter during reentry have been calculated from acceleration measurements made by the High Resolution Accelerometer Package (HiRAP) and the Orbiter Inertial Measurement Unit (IMU) liner accelerometers. The atmospheric density data developed from this study represent a significant gain with respect to the body of data collected to date by various techniques in the altitude range of 60 to 160 km. The data are unique in that they cover a very wide horizontal range during each flight and provide insight into the actual density variations encountered along the reentry flight path. The data, which were collected over about 3 years, are also characterized by variations in solar activity, geomagnetic index, and local solar time. Comparison of the flight-derived densities with various atmospheric models have been made, and analyses have attempted to characterize the data and to show correlation with selected physical variables.

A rotor-mounted digital instrumentation system for helicopter blade flight research measurements

NASA Technical Reports Server (NTRS)

Knight, V. H., Jr.; Haywood, W. S., Jr.; Williams, M. L.

1978-01-01

A rotor mounted flight instrumentation system developed for helicopter rotor blade research is described. The system utilizes high speed digital techniques to acquire research data from miniature pressure transducers on advanced rotor airfoils which are flight tested on an AH-1G helicopter. The system employs microelectronic pulse code modulation (PCM) multiplexer digitizer stations located remotely on the blade and in a hub mounted metal canister. As many as 25 sensors can be remotely digitized by a 2.5 mm thick electronics package mounted on the blade near the tip to reduce blade wiring. The electronics contained in the canister digitizes up to 16 sensors, formats these data with serial PCM data from the remote stations, and transmits the data from the canister which is above the plane of the rotor. Data are transmitted over an RF link to the ground for real time monitoring and to the helicopter fuselage for tape recording. The complete system is powered by batteries located in the canister and requires no slip rings on the rotor shaft.

Foundations of low-temperature plasma physics—an introduction

NASA Astrophysics Data System (ADS)

von Keudell, A.; Schulz-von der Gathen, V.

2017-11-01

The use of plasmas as a reactive mixture of ions, electrons and neutrals is at the core of numerous technologies in industry, enabling applications in microelectronics, automotives, packaging, environment and medicine. Recently, even the use of plasmas in medical applications has made great progress. The dominant character of a plasma is often its non equilibrium nature with different temperatures for the individual species in a plasma, the ions, electrons and neutrals. This opens up a multitude of reaction pathways which are inaccessible to conventional methods in chemistry, for example. The understanding of plasmas requires expertise in plasma physics, plasma chemistry and in electrical engineering. This first paper in a series of foundation papers on low temperature plasma science is intended to provide the very basics of plasmas as a common starting point for the more in-depth discussion of particular plasma generation methods, plasma modeling and diagnostics in the other foundation papers. In this first paper of the series, the common terminology, definitions and main concepts are introduced. The covered aspects start with the basic definitions and include further plasma equilibria, particle collisions and transport, sheaths and discharge breakdowns.

MIRAGE: developments in IRSP systems, RIIC design, emitter fabrication, and performance

NASA Astrophysics Data System (ADS)

Bryant, Paul; Oleson, Jim; James, Jay; McHugh, Steve; Lannon, John; Vellenga, David; Goodwin, Scott; Huffman, Alan; Solomon, Steve; Goldsmith, George C., II

2005-05-01

SBIR's family of MIRAGE infrared scene projection systems is undergoing significant growth and expansion. The first two lots of production IR emitters have completed fabrication at Microelectronics Center of North Carolina/Research and Development Institute (MCNC-RDI), and the next round(s) of emitter production has begun. These latest emitter arrays support programs such as Large Format Resistive Array (LFRA), Optimized Array for Space-based Infrared Simulation (OASIS), MIRAGE 1.5, and MIRAGE II. We present the latest performance data on emitters fabricated at MCNC-RDI, plus integrated system performance on recently completed IRSP systems. Teamed with FLIR Systems/Indigo Operations, SBIR and the Tri-Services IRSP Working Group have completed development of the CMOS Read-In Integrated Circuit (RIIC) portion of the Wide Format Resistive Array (WFRA) program-to extend LFRA performance to a 768 x 1536 "wide screen" projection configuration. WFRA RIIC architecture and performance is presented. Finally, we summarize development of the LFRA Digital Emitter Engine (DEE) and OASIS cryogenic package assemblies, the next-generation Command & Control Electronics (C&CE).

Microengineering of magnetic bearings and actuators

NASA Astrophysics Data System (ADS)

Ghantasala, Muralihar K.; Qin, LiJiang; Sood, Dinesh K.; Zmood, Ronald B.

2000-06-01

Microengineering has evolved in the last decade as a subject of its own with the current research encompassing every possible area of devices from electromagnetic to optical and bio-micro electromechanical systems (MEMS). The primary advantage of the micro system technology is its small size, potential to produce high volume and low cost devices. However, the major impediments in the successful realization of many micro devices in practice are the reliability, packaging and integration with the existing microelectronics technology. Microengineering of actuators has recently grown tremendously due to its possible applicability to a wide range of devices of practical importance and the availability of a choice of materials. Selection of materials has been one of the important aspects of the design and fabrication of many micro system and actuators. This paper discusses the issues related to the selection of materials and subsequently their effect on the performance of the actuator. These will be discussed taking micro magnetic actuators and bearings, in particular, as examples. Fabrication and processing strategies and performance evaluation methods adopted will be described. Current status of the technology and projected futuristic applications in this area will be reviewed.

Materials and processing science: Limits for microelectronics

NASA Astrophysics Data System (ADS)

Rosenberg, R.

1988-09-01

The theme of this talk will be to illustrate examples of technologies that will drive materials and processing sciences to the limit and to describe some of the research being pursued to understand materials interactions which are pervasive to projected structure fabrication. It is to be expected that the future will see a progression to nanostructures where scaling laws will be tested and quantum transport will become more in evidence, to low temperature operation for tighter control and improved performance, to complex vertical profiles where 3D stacking and superlattices will produce denser packing and device flexibility, to faster communication links with optoelectronics, and to compatible packaging technologies. New low temperature processing techniques, such as epitaxy of silicon, PECVD of dielectrics, low temperature high pressure oxidation, silicon-germanium heterostructures, etc., must be combined with shallow metallurgies, new lithographic technologies, maskless patterning, rapid thermal processing (RTP) to produce needed profile control, reduce process incompatibilities and develop new device geometries. Materials interactions are of special consequence for chip substrates and illustrations of work in metal-ceramic and metal-polymer adhesion will be offered.

Prediction of LDEF ionizing radiation environment

NASA Astrophysics Data System (ADS)

Watts, John W.; Parnell, T. A.; Derrickson, James H.; Armstrong, T. W.; Benton, E. V.

1992-01-01

The Long Duration Exposure Facility (LDEF) spacecraft flew in a 28.5 deg inclination circular orbit with an altitude in the range from 172 to 258.5 nautical miles. For this orbital altitude and inclination two components contribute most of the penetrating charge particle radiation encountered - the galactic cosmic rays and the geomagnetically trapped Van Allen protons. Where shielding is less than 1.0 g/sq cm geomagnetically trapped electrons make a significant contribution. The 'Vette' models together with the associated magnetic filed models were used to obtain the trapped electron and proton fluences. The mission proton doses were obtained from the fluence using the Burrell proton dose program. For the electron and bremsstrahlung dose we used the Marshall Space Flight Center (MSFC) electron dose program. The predicted doses were in general agreement with those measured with on-board thermoluminescent detector (TLD) dosimeters. The NRL package of programs, Cosmic Ray Effects on MicroElectronics (CREME), was used to calculate the linear energy transfer (LET) spectrum due to galactic cosmic rays (GCR) and trapped protons for comparison with LDEF measurements.

Laser alchemy: direct writing of multifunctional components in a glass chip with femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Liao, Yang; Lin, Jintian; Cheng, Ya

2013-12-01

Recently, hybrid integration of multifunctional micro-components for creating complex, intelligent micro/nano systems has attracted significant attention. These micro-/nano-systems have important applications in a variety of areas, such as healthcare, environment, communication, national security, and so on. However, fabrication of micro/nano systems incorporated with different functions is still a challenging task, which generally requires fabrication of discrete microcomponents beforehand followed by assembly and packaging procedures. Furthermore, current micro-/nano-fabrication techniques are mainly based on the well-established planar lithographic approach, which suffer from severe issues in producing three dimensional (3D) structures with complex geometries and arbitrary configurations. In recent years, the rapid development of femtosecond laser machining technology has enabled 3D direct fabrication and integration of multifunctional components, such as microfluidics, microoptics, micromechanics, microelectronics, etc., into single substrates. In this invited talk, we present our recent progress in this active area. Particularly, we focus on fabrication of 3D micro- and nanofluidic devices and 3D high-Q microcavities in glass substrates by femtosecond laser direct writing.

Optimal segmentation and packaging process

DOEpatents

Kostelnik, K.M.; Meservey, R.H.; Landon, M.D.

1999-08-10

A process for improving packaging efficiency uses three dimensional, computer simulated models with various optimization algorithms to determine the optimal segmentation process and packaging configurations based on constraints including container limitations. The present invention is applied to a process for decontaminating, decommissioning (D and D), and remediating a nuclear facility involving the segmentation and packaging of contaminated items in waste containers in order to minimize the number of cuts, maximize packaging density, and reduce worker radiation exposure. A three-dimensional, computer simulated, facility model of the contaminated items are created. The contaminated items are differentiated. The optimal location, orientation and sequence of the segmentation and packaging of the contaminated items is determined using the simulated model, the algorithms, and various constraints including container limitations. The cut locations and orientations are transposed to the simulated model. The contaminated items are actually segmented and packaged. The segmentation and packaging may be simulated beforehand. In addition, the contaminated items may be cataloged and recorded. 3 figs.

Home page | prc.gatech.edu | Georgia Institute of Technology | Atlanta, GA

Science.gov Websites

Interconnections & Assembly Low Cost Glass Interposers & Packages MEMS and Sensors GRA Opportunities addressing electrical, mechanical and thermal barriers. Low-cost Glass Interposer and Package Panel-based ultra-thin glass as a high performance, high I/O density, and low cost platform. Interconnections and

Peering down the barrel of a bacteriophage portal: the genome packaging and release valve in p22.

PubMed

Tang, Jinghua; Lander, Gabriel C; Olia, Adam S; Olia, Adam; Li, Rui; Casjens, Sherwood; Prevelige, Peter; Cingolani, Gino; Baker, Timothy S; Johnson, John E

2011-04-13

The encapsidated genome in all double-strand DNA bacteriophages is packaged to liquid crystalline density through a unique vertex in the procapsid assembly intermediate, which has a portal protein dodecamer in place of five coat protein subunits. The portal orchestrates DNA packaging and exit, through a series of varying interactions with the scaffolding, terminase, and closure proteins. Here, we report an asymmetric cryoEM reconstruction of the entire P22 virion at 7.8 Å resolution. X-ray crystal structure models of the full-length portal and of the portal lacking 123 residues at the C terminus in complex with gene product 4 (Δ123portal-gp4) obtained by Olia et al. (2011) were fitted into this reconstruction. The interpreted density map revealed that the 150 Å, coiled-coil, barrel portion of the portal entraps the last DNA to be packaged and suggests a mechanism for head-full DNA signaling and transient stabilization of the genome during addition of closure proteins. Copyright © 2011 Elsevier Ltd. All rights reserved.

Microelectronics Status Analysis and Secondary Part Procureability Assessment of the THAAD Weapon System

DTIC Science & Technology

1999-10-01

Technical Report 5-20448 & 5- 20449 Contract No. DAAH01-98-D-R001 Delivery Order No. 34 Microelectronics Status Analysis and Secondary Part...Procureability Assessment of the THAAD Weapon System. (5-20448 & 5- 20449 ) Final Technical Report for Period 21 January 1999 through 30 September 1999...Huntsville Huntsville, AL 35899 5. FUNDING NUMBERS 8. PERFORMING ORGANIZATION REPORT NUMBER 5-20448 & 5- 20449 9. SPONSORING/MONITORING AGENCY

Reduction of particle deposition on substrates using temperature gradient control

DOEpatents

Rader, Daniel J.; Dykhuizen, Ronald C.; Geller, Anthony S.

2000-01-01

A method of reducing particle deposition during the fabrication of microelectronic circuitry is presented. Reduction of particle deposition is accomplished by controlling the relative temperatures of various parts of the deposition system so that a large temperature gradient near the surface on which fabrication is taking place exists. This temperature gradient acts to repel particles from that surface, thereby producing cleaner surfaces, and thus obtaining higher yields from a given microelectronic fabrication process.

Electromagnetic Compatibility (EMC) in Microelectronics.

DTIC Science & Technology

1983-02-01

Fault Tree Analysis", System Saftey Symposium, June 8-9, 1965, Seattle: The Boeing Company . 12. Fussell, J.B., "Fault Tree Analysis-Concepts and...procedure for assessing EMC in microelectronics and for applying DD, 1473 EOiTO OP I, NOV6 IS OESOL.ETE UNCLASSIFIED SECURITY CLASSIFICATION OF THIS...CRITERIA 2.1 Background 2 2.2 The Probabilistic Nature of EMC 2 2.3 The Probabilistic Approach 5 2.4 The Compatibility Factor 6 3 APPLYING PROBABILISTIC

Radiation measurement in the environment of FLASH using passive dosimeters

NASA Astrophysics Data System (ADS)

Mukherjee, B.; Rybka, D.; Makowski, D.; Lipka, T.; Simrock, S.

2007-08-01

Sophisticated electronic devices comprising sensitive microelectronic components have been installed in the close proximity of the 720 MeV superconducting electron linear accelerator (linac) driving the FLASH (Free Electron Laser in Hamburg), presently in operation at DESY in Hamburg. Microelectronic chips are inherently vulnerable to ionizing radiation, usually generated during routine operation of high-energy particle accelerator facilities like the FLASH. Hence, in order to assess the radiation effect on microelectronic chips and to develop suitable mitigation strategy, it becomes imperative to characterize the radiation field in the FLASH environment. We have evaluated the neutron and gamma energy (spectra) and dose distributions at critical locations in the FLASH tunnel using superheated emulsion (bubble) detectors, GaAs light emitting diodes (LED), LiF-thermoluminescence dosimeters (TLD) and radiochromic (Gafchromic EBT) films. This paper highlights the application of passive dosimeters for an accurate analysis of the radiation field produced by high-energy electron linear accelerators.

Laser processing of ceramics for microelectronics manufacturing

NASA Astrophysics Data System (ADS)

Sposili, Robert S.; Bovatsek, James; Patel, Rajesh

2017-03-01

Ceramic materials are used extensively in the microelectronics, semiconductor, and LED lighting industries because of their electrically insulating and thermally conductive properties, as well as for their high-temperature-service capabilities. However, their brittleness presents significant challenges for conventional machining processes. In this paper we report on a series of experiments that demonstrate and characterize the efficacy of pulsed nanosecond UV and green lasers in machining ceramics commonly used in microelectronics manufacturing, such as aluminum oxide (alumina) and aluminum nitride. With a series of laser pocket milling experiments, fundamental volume ablation rate and ablation efficiency data were generated. In addition, techniques for various industrial machining processes, such as shallow scribing and deep scribing, were developed and demonstrated. We demonstrate that lasers with higher average powers offer higher processing rates with the one exception of deep scribes in aluminum nitride, where a lower average power but higher pulse energy source outperformed a higher average power laser.

RF plasma cleaning of silicon substrates with high-density polyethylene contamination

NASA Astrophysics Data System (ADS)

Cagomoc, Charisse Marie D.; De Leon, Mark Jeffry D.; Ebuen, Anna Sophia M.; Gilos, Marlo Nicole R.; Vasquez, Magdaleno R., Jr.

2018-01-01

Upon contact with a polymeric material, microparticles from the polymer may adhere to a silicon (Si) substrate during device processing. The adhesion contaminates the surface and, in turn, leads to defects in the fabricated Si-based microelectronic devices. In this study, Si substrates with artificially induced high-density polyethylene (HDPE) contamination was exposed to 13.56 MHz radio frequency (RF) plasma utilizing argon and oxygen gas admixtures at a power density of 5.6 W/cm2 and a working pressure of 110 Pa for up to 6 min of treatment. Optical microscopy studies revealed the removal of up to 74% of the polymer contamination upon plasma exposure. Surface free energy (SFE) increased owing to the removal of contaminants as well as the formation of polar groups on the Si surface after plasma treatment. Atomic force microscopy scans showed a decrease in surface roughness from 12.25 nm for contaminated samples to 0.77 nm after plasma cleaning. The smoothening effect can be attributed to the removal of HDPE particles from the surface. In addition, scanning electron microscope images showed that there was a decrease in the amount of HDPE contaminants adhering onto the surface after plasma exposure.

Stability Study of Sunscreens with Free and Encapsulated UV Filters Contained in Plastic Packaging

PubMed Central

Briasco, Benedetta; Capra, Priscilla; Mannucci, Barbara; Perugini, Paola

2017-01-01

Sunscreens play a fundamental role in skin cancer prevention and in protection against photo-aging. UV filters are often photo-unstable, especially in relation to their vehicles and, being lipophilic substances, they are able to interact with plastic packaging. Finally, UV filter stability can be significantly affected by the routine use of the product at high temperatures. This work aims to study the stability of sunscreen formulations in polyethylene packaging. Butyl methoxydibenzoylmethane and octocrylene, both in a free form and as encapsulated filters were chosen as UV filters. Stability evaluations were performed both in the packaging and on the formulations. Moreover, a further two non-destructive techniques, near-infrared (NIR) spectroscopy and a multiple light scattering technique, were also used to evaluate the stability of the formulation. Results demonstrated clearly that all of the pack underwent significant changes in its elastic/plastic behavior and in external color after solar irradiation. From the evaluation of the extractable profile of untreated and treated packaging material an absorption of 2-phenoxyethanol and octocrylene were shown. In conclusion, the results highlighted clearly that a reduction of the UV filter in the formulation packed in high-density polyethylene/low-density polyethylene (HDPE/LDPE) material can occur over time, reducing the protective effect of the product when applied to the skin. PMID:28561775

Stability Study of Sunscreens with Free and Encapsulated UV Filters Contained in Plastic Packaging.

PubMed

Briasco, Benedetta; Capra, Priscilla; Mannucci, Barbara; Perugini, Paola

2017-05-31

Sunscreens play a fundamental role in skin cancer prevention and in protection against photo-aging. UV filters are often photo-unstable, especially in relation to their vehicles and, being lipophilic substances, they are able to interact with plastic packaging. Finally, UV filter stability can be significantly affected by the routine use of the product at high temperatures. This work aims to study the stability of sunscreen formulations in polyethylene packaging. Butyl methoxydibenzoylmethane and octocrylene, both in a free form and as encapsulated filters were chosen as UV filters. Stability evaluations were performed both in the packaging and on the formulations. Moreover, a further two non-destructive techniques, near-infrared (NIR) spectroscopy and a multiple light scattering technique, were also used to evaluate the stability of the formulation. Results demonstrated clearly that all of the pack underwent significant changes in its elastic/plastic behavior and in external color after solar irradiation. From the evaluation of the extractable profile of untreated and treated packaging material an absorption of 2-phenoxyethanol and octocrylene were shown. In conclusion, the results highlighted clearly that a reduction of the UV filter in the formulation packed in high-density polyethylene/low-density polyethylene (HDPE/LDPE) material can occur over time, reducing the protective effect of the product when applied to the skin.

PREFACE: E-MRS 2012 Spring Meeting, Symposium M: More than Moore: Novel materials approaches for functionalized Silicon based Microelectronics

NASA Astrophysics Data System (ADS)

Wenger, Christian; Fompeyrine, Jean; Vallée, Christophe; Locquet, Jean-Pierre

2012-12-01

More than Moore explores a new area of Silicon based microelectronics, which reaches beyond the boundaries of conventional semiconductor applications. Creating new functionality to semiconductor circuits, More than Moore focuses on motivating new technological possibilities. In the past decades, the main stream of microelectronics progresses was mainly powered by Moore's law, with two focused development arenas, namely, IC miniaturization down to nano scale, and SoC based system integration. While the microelectronics community continues to invent new solutions around the world to keep Moore's law alive, there is increasing momentum for the development of 'More than Moore' technologies which are based on silicon technologies but do not simply scale with Moore's law. Typical examples are RF, Power/HV, Passives, Sensor/Actuator/MEMS or Bio-chips. The More than Moore strategy is driven by the increasing social needs for high level heterogeneous system integration including non-digital functions, the necessity to speed up innovative product creation and to broaden the product portfolio of wafer fabs, and the limiting cost and time factors of advanced SoC development. It is believed that More than Moore will add value to society on top of and beyond advanced CMOS with fast increasing marketing potentials. Important key challenges for the realization of the 'More than Moore' strategy are: perspective materials for future THz devices materials systems for embedded sensors and actuators perspective materials for epitaxial approaches material systems for embedded innovative memory technologies development of new materials with customized characteristics The Hot topics covered by the symposium M (More than Moore: Novel materials approaches for functionalized Silicon based Microelectronics) at E-MRS 2012 Spring Meeting, 14-18 May 2012 have been: development of functional ceramics thin films New dielectric materials for advanced microelectronics bio- and CMOS compatible material systems piezoelectric films and nanostructures Atomic Layer Deposition (ALD) of oxides and nitrides characterization and metrology of very thin oxide layers We would like to take this opportunity to thank the Scientific Committee and Local Committee for bringing together a coherent and high quality Symposium at E-MRS 2012 Spring Meeting. Christian Wenger, Jean Fompeyrine, Christophe Vallée and Jean-Pierre Locquet Organizing Committee of Symposium M September 2012

The NASA Electronic Parts and Packaging (NEPP) Program: Overview and the New Tenets for Cost Conscious Mission Assurance on Electrical, Electronic, and Electromechanical (EEE) Parts

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Sampson, Michael J.

2015-01-01

The NEPP Program focuses on the reliability aspects of electronic devices (integrated circuits such as a processor in a computer). There are three principal aspects of this reliability: 1) Lifetime, inherent failure and design issues related to the EEE parts technology and packaging; 2) Effects of space radiation and the space environment on these technologies, and; 3) Creation and maintenance of the assurance support infrastructure required for mission success. The NEPP mission is to provide guidance to NASA for the selection and application of microelectronics technologies, to improve understanding of the risks related to the use of these technologies in the space environment, and to ensure that appropriate EEE parts research is performed to meet NASA mission assurance needs. NEPPs FY15 goals are to represent the NASA voice to the greater aerospace EEE parts community including supporting anti-counterfeit and trust, provide relevant guidance to cost-effective missions, aid insertion of advanced (and commercial) technologies, resolve unexpected parts issues, ensure access to appropriate radiation test facilities, and collaborate as widely as possible with external entities. In accordance with the changing mission profiles throughout NASA, the NEPP Program has developed a balanced portfolio of efforts to provide agency-wide assurance for not only traditional spacecraft developments, but also those in-line with the new philosophies emerging worldwide. In this presentation, we shall present an overview of this program and considerations for EEE parts assurance as applied to cost conscious missions.

Evaluation of Thermo-Mechanical Stability of COTS Dual-Axis MEMS Accelerometers for Space Applications

NASA Technical Reports Server (NTRS)

Sharma, Ashok K.; Teverovksy, Alexander; Day, John H. (Technical Monitor)

2000-01-01

Microelectromechanical systems in MEMS is one of the fastest growing technologies in microelectronics, and is of great interest for military and aerospace applications. Accelerometers are the earliest and most developed representatives of MEMS. First demonstrated in 1979, micromachined accelerometers were used in automobile industry for air bag crash- sensing applications since 1990. In 1999, N4EMS accelerometers were used in NASA-JPL Mars Microprobe. The most developed accelerometers for airbag crash- sensing are rated for a full range of +/- 50 G. The range of sensitivity for accelerometers required for military or aerospace applications is much larger, varying from 20,000 G (to measure acceleration during gun and ballistic munition launches), and to 10(exp -6) G, when used as guidance sensors (to measure attitude and position of a spacecraft). The presence of moving parts on the surface of chip is specific to MEMS, and particularly, to accelerometers. This characteristic brings new reliability issues to micromachined accelerometers, including cyclic fatigue cracking of polysilicon cantilevers and springs, mechanical stresses that are caused by packaging and contamination in the internal cavity of the package. Studies of fatigue cracks initiation and growth in polysilicon showed that the fatigue damage may influence MEMS device performance, and the presence of water vapor significantly enhances crack initiation and growth. Environmentally induced failures, particularly, failures due to thermal cycling and mechanical shock are considered as one of major reliability concerns in MEMS. These environmental conditions are also critical for space applications of the parts. For example, the Mars pathfinder mission had experienced 80 mechanical shock events during the pyrotechnic separation processes.

Surface cleaning for enhanced adhesion to packaging surfaces: Effect of oxygen and ammonia plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaddam, Sneha; Dong, Bin; Driver, Marcus

2015-03-15

The effects of direct plasma chemistries on carbon removal from silicon nitride (SiN{sub x}) and oxynitride (SiO{sub x}N{sub y}) surfaces have been studied by in-situ x-ray photoelectron spectroscopy (XPS) and ex-situ contact angle measurements. The data indicate that O{sub 2} and NH{sub 3} capacitively coupled plasmas are effective at removing adventitious carbon from silicon nitride (SiN{sub x}) and Si oxynitride (SiO{sub x}N{sub y}) surfaces. O{sub 2} plasma treatment results in the formation of a silica overlayer. In contrast, the exposure to NH{sub 3} plasma results in negligible additional oxidation of the SiN{sub x} or SiO{sub x}N{sub y} surface. Ex-situ contactmore » angle measurements show that SiN{sub x} and SiO{sub x}N{sub y} surfaces exposed to oxygen plasma are initially more hydrophilic than surfaces exposed to NH{sub 3} plasma, indicating that the O{sub 2} plasma-induced SiO{sub 2} overlayer is highly reactive toward ambient. At longer ambient exposures (≳10 h), however, surfaces treated by either O{sub 2} or NH{sub 3} plasma exhibit similar steady state contact angles, correlated with rapid uptake of adventitious carbon, as determined by XPS. Surface passivation by exposure to molecular hydrogen prior to ambient exposure significantly retards the increase in contact angle upon exposure to ambient. The results suggest a practical route to enhancing the time available for effective bonding to surfaces in microelectronics packaging applications.« less

Stochastic approach for radionuclides quantification

NASA Astrophysics Data System (ADS)

Clement, A.; Saurel, N.; Perrin, G.

2018-01-01

Gamma spectrometry is a passive non-destructive assay used to quantify radionuclides present in more or less complex objects. Basic methods using empirical calibration with a standard in order to quantify the activity of nuclear materials by determining the calibration coefficient are useless on non-reproducible, complex and single nuclear objects such as waste packages. Package specifications as composition or geometry change from one package to another and involve a high variability of objects. Current quantification process uses numerical modelling of the measured scene with few available data such as geometry or composition. These data are density, material, screen, geometric shape, matrix composition, matrix and source distribution. Some of them are strongly dependent on package data knowledge and operator backgrounds. The French Commissariat à l'Energie Atomique (CEA) is developing a new methodology to quantify nuclear materials in waste packages and waste drums without operator adjustment and internal package configuration knowledge. This method suggests combining a global stochastic approach which uses, among others, surrogate models available to simulate the gamma attenuation behaviour, a Bayesian approach which considers conditional probability densities of problem inputs, and Markov Chains Monte Carlo algorithms (MCMC) which solve inverse problems, with gamma ray emission radionuclide spectrum, and outside dimensions of interest objects. The methodology is testing to quantify actinide activity in different kind of matrix, composition, and configuration of sources standard in terms of actinide masses, locations and distributions. Activity uncertainties are taken into account by this adjustment methodology.

SETA Support for the DARPA Microelectronics Technology Insertion Program of the Microelectronics Technology Office

DTIC Science & Technology

1992-08-17

Conclusions. Key personnel planned and administered the 193-nm lithography SBIR workshop on May 7, 1992 as well as planned the GaAs Insertion...converters can use Josephson junctions (JJ) to improve performance. Superconductive quantum interference devices (SQUIDs), such as JJs, are used to form...forward control of a lithography stepper. Mark Conner at Booz-Allen has copies of the charts. You should take a few minutes to review them. I asked Costos

A Low Cost Rad-Tolerant Standard Cell Library

NASA Technical Reports Server (NTRS)

Gambles, Jody W.; Maki, Gary K.

1997-01-01

This paper describes circuit design techniques developed at the NASA Institute of Advanced Microelectronics that have been shown to protect CMOS circuits from the deleterious effects of the natural space radiation environment. The IAuE is leading a program to incorporate these radiation-tolerance providing design techniques into a commercial standard cell library that will be used in conjunction with available Electronic Design Automation tools to produce space flight qualified microelectronics fabricated at modern commercial CMOS foundries.

Development and ESCC evaluation of a monolithic silicon phototransistor array for optical encoders

NASA Astrophysics Data System (ADS)

Bregoli, M.; Ceriani, S.; Erspan, M.; Collini, A.; Ficorella, F.; Giacomini, G.; Bellutti, P.; How, L. S.; Hernandez, S.; Lundmark, K.

2017-11-01

Optoelettronica Italia Srl, better known as Optoi, is an Italian Company dealing with optoelectronics and microelectronics and focusing on back-end technologies. The growing volume of activities concerning the aerospace field has recently brought to the creation of a company unit, with collaborations with ESA, CNES and ASI. In this context, Optoi's key partner for the microelectronic front-end is Fondazione Bruno Kessler (FBK) and specifically its Micro Nano Facility (MNF).

Preliminary Flight Results of the Microelectronics and Photonics Test Bed: NASA DR1773 Fiber Optic Data Bus Experiment

NASA Technical Reports Server (NTRS)

Jackson, George L.; LaBel, Kenneth A.; Marshall, Cheryl; Barth, Janet; Seidleck, Christina; Marshall, Paul

1998-01-01

NASA Goddard Spare Flight Center's (GSFC) Dual Rate 1773 (DR1773) Experiment on the Microelectronic and Photonic Test Bed (MPTB) has provided valuable information on the performance of the AS 1773 fiber optic data bus in the space radiation environment. Correlation of preliminary experiment data to ground based radiation test results show the AS 1773 bus is employable in future spacecraft applications requiring radiation tolerant communication links.

Investigation of Expandable Polymeric Microspheres for Packaging Applications

DTIC Science & Technology

2012-06-06

FILMS COST REDUCTION OLEFIN POLYMERS COSTS PACKAGING MICROSPHERES WASTE DISPOSAL WEIGHT...MANAGEMENT THERMAL INSULATION DENSITY SOLID WASTES ENVIRONMENTAL IMPACT THERMOPLASTIC POLYMERS POLYMERS ...research. The purpose was to provide information on the incorporation of hollow, expandable  polymeric microspheres  into  thermoplastic   polymers   to

Simulation-based Bayesian inference for latent traits of item response models: Introduction to the ltbayes package for R.

PubMed

Johnson, Timothy R; Kuhn, Kristine M

2015-12-01

This paper introduces the ltbayes package for R. This package includes a suite of functions for investigating the posterior distribution of latent traits of item response models. These include functions for simulating realizations from the posterior distribution, profiling the posterior density or likelihood function, calculation of posterior modes or means, Fisher information functions and observed information, and profile likelihood confidence intervals. Inferences can be based on individual response patterns or sets of response patterns such as sum scores. Functions are included for several common binary and polytomous item response models, but the package can also be used with user-specified models. This paper introduces some background and motivation for the package, and includes several detailed examples of its use.

Assessment of Quality Assurance Measures for Radioactive Material Transport Packages not Requiring Competent Authority Design Approval - 13282

DOE Office of Scientific and Technical Information (OSTI.GOV)

Komann, Steffen; Groeke, Carsten; Droste, Bernhard

The majority of transports of radioactive materials are carried out in packages which don't need a package design approval by a competent authority. Low-active radioactive materials are transported in such packages e.g. in the medical and pharmaceutical industry and in the nuclear industry as well. Decommissioning of NPP's leads to a strong demand for packages to transport low and middle active radioactive waste. According to IAEA regulations the 'non-competent authority approved package types' are the Excepted Packages and the Industrial Packages of Type IP-1, IP-2 and IP-3 and packages of Type A. For these types of packages an assessment bymore » the competent authority is required for the quality assurance measures for the design, manufacture, testing, documentation, use, maintenance and inspection (IAEA SSR 6, Chap. 306). In general a compliance audit of the manufacturer of the packaging is required during this assessment procedure. Their regulatory level in the IAEA regulations is not comparable with the 'regulatory density' for packages requiring competent authority package design approval. Practices in different countries lead to different approaches within the assessment of the quality assurance measures in the management system as well as in the quality assurance program of a special package design. To use the package or packaging in a safe manner and in compliance with the regulations a management system for each phase of the life of the package or packaging is necessary. The relevant IAEA-SSR6 chap. 801 requires documentary verification by the consignor concerning package compliance with the requirements. (authors)« less

Optimization of Indium Bump Morphology for Improved Flip Chip Devices

NASA Technical Reports Server (NTRS)

Jones, Todd J.; Nikzad, Shouleh; Cunningham, Thomas J.; Blazejewski, Edward; Dickie, Matthew R.; Hoenk, Michael E.; Greer, Harold F.

2011-01-01

Flip-chip hybridization, also known as bump bonding, is a packaging technique for microelectronic devices that directly connects an active element or detector to a substrate readout face-to-face, eliminating the need for wire bonding. In order to make conductive links between the two parts, a solder material is used between the bond pads on each side. Solder bumps, composed of indium metal, are typically deposited by thermal evaporation onto the active regions of the device and substrate. While indium bump technology has been a part of the electronic interconnect process field for many years and has been extensively employed in the infrared imager industry, obtaining a reliable, high-yield process for high-density patterns of bumps can be quite difficult. Under the right conditions, a moderate hydrogen plasma exposure can raise the temperature of the indium bump to the point where it can flow. This flow can result in a desirable shape where indium will efficiently wet the metal contact pad to provide good electrical contact to the underlying readout or imager circuit. However, it is extremely important to carefully control this process as the intensity of the hydrogen plasma treatment dramatically affects the indium bump morphology. To ensure the fine-tuning of this reflow process, it is necessary to have realtime feedback on the status of the bumps. With an appropriately placed viewport in a plasma chamber, one can image a small field (a square of approximately 5 millimeters on each side) of the bumps (10-20 microns in size) during the hydrogen plasma reflow process. By monitoring the shape of the bumps in real time using a video camera mounted to a telescoping 12 magnifying zoom lens and associated optical elements, an engineer can precisely determine when the reflow of the bumps has occurred, and can shut off the plasma before evaporation or de-wetting takes place.

US Food Industry Progress During the National Salt Reduction Initiative: 2009-2014.

PubMed

Curtis, Christine J; Clapp, Jenifer; Niederman, Sarah A; Ng, Shu Wen; Angell, Sonia Y

2016-10-01

To assess the US packaged food industry's progress from 2009 to 2014, when the National Salt Reduction Initiative had voluntary, category-specific sodium targets with the goal of reducing sodium in packaged and restaurant foods by 25% over 5 years. Using the National Salt Reduction Initiative Packaged Food Database, we assessed target achievement and change in sales-weighted mean sodium density in top-selling products in 61 food categories in 2009 (n = 6336), 2012 (n = 6898), and 2014 (n = 7396). In 2009, when the targets were established, no categories met National Salt Reduction Initiative 2012 or 2014 targets. By 2014, 26% of categories met 2012 targets and 3% met 2014 targets. From 2009 to 2014, the sales-weighted mean sodium density declined significantly in almost half of all food categories (43%; 26/61 categories). Overall, sales-weighted mean sodium density declined significantly (by 6.8%; P < .001). National target setting with monitoring through a partnership of local, state, and national health organizations proved feasible, but industry progress was modest. The US Food and Drug Administration's proposed voluntary targets will be an important step in achieving more substantial sodium reductions.

Interconnect mechanisms in microelectronic packaging

NASA Astrophysics Data System (ADS)

Roma, Maria Penafrancia C.

Global economic, environmental and market developments caused major impact in the microelectronics industry. Astronomical rise of gold metal prices over the last decade shifted the use of copper and silver alloys as bonding wires. Environmental legislation on the restriction of the use of Pb launched worldwide search for lead-free solders and platings. Finally, electrical and digital uses demanded smaller, faster and cheaper devices. Ultra-fine pitch bonding, decreasing bond wire sizes and hard to bond substrates have put the once-robust stitch bond in the center of reliability issues due to stitch bond lift or open wires .Unlike the ball bond, stitch bonding does not lead to intermetallic compound formation but adhesion is dependent on mechanical deformation, interdiffusion, solid solution formation, void formation and mechanical interlocking depending on the wire material, bond configuration, substrate type , thickness and surface condition. Using Au standoff stitch bonds on NiPdAu plated substrates eliminated stitch bond lift even when the Au and Pd layers are reduced. Using the Matano-Boltzmann analysis on a STEM (Scanning Transmission Analysis) concentration profile the interdiffusion coefficient is measured to be 10-16 cm 2/s. Wire pull strength data showed that the wire pull strength is 0.062N and increases upon stress testing. Meanwhile, coating the Cu wire with Pd, not only increases oxidation resistance but also improved adhesion due to the formation of a unique interfacial adhesion layers. Adhesion strength as measured by pull showed the Cu wire bonded to Ag plated Cu substrate (0.132N) to be stronger than the Au wire bonded on the same substrate (0.124N). Ag stitch bonded to Au is predicted to be strong but surface modification made the adhesion stronger. However, on the Ag ball bonded to Al showed multiple IMC formation with unique morphology exposed by ion milling and backscattered scanning electron microscopy. Adding alloying elements in the Ag wire alloy showed differences in adhesion strength and IMC formation. Bond strength by wire pull testing showed the 95Ag alloy with higher values while shear bond testing showed the 88Ag higher bond strength. Use of Cu pillars in flip chips and eutectic bonding in wafer level chip scale packages are direct consequences of diminishing interconnect dimension as a result of the drive for miniaturization. The combination of Cu-Sn interdiffusion, Kirkendall mechanism and heterogeneous vacancy precipitation are the main causes of IMC and void formation in Cu pillar - Sn solder - Cu lead frame sandwich structure. However, adding a Ni barrier agent showed less porous IMC layer as well as void formation as a result of the modified Cu and Sn movement well as the void formation. Direct die to die bonding using Al-Ge eutectic bonds is necessary when 3D integration is needed to reduce the footprint of a package. Hermeticity and adhesion strength are a function of the Al/Ge thickness ratio, bonding pressure, temperature and time. Scanning Electron Microscope (SEM) and Focused Ion Beam (FIB) allowed imaging of interfacial microstructures, porosity, grain morphology while Scanning Transmission Electron microscope (STEM) provided diffusion profile and confirmed interdiffusion. Ion polishing technique provided information on porosity and when imaged using backscattered mode, grain structure confirmed mechanical deformation of the bonds. Measurements of the interfacial bond strength are made by wire pull tests and ball shear tests based on existing industry standard tests. However, for the Al-Ge eutectic bonds, no standard strength is available so a test is developed using the stud pull test method using the Dage 4000 Plus to yield consistent results. Adhesion strengths of 30-40 MPa are found for eutectic bonded packages however, as low as 20MPa was measured in low temperature bonded areas.

VIBRATION TESTING OF RESILIENT PACKAGE CUSHIONING MATERIALS

DTIC Science & Technology

government and industry. Testing equipment which meets tentative ASTM requirements was developed. Preliminary tests were conducted on a resilient expanded ... polystyrene foam (in 3 densities) and a polyether urethane foam (in one density). When vibrated under static loads known to provide optimum shock

Electronics for better healthcare.

PubMed

Wolf, Bernhard; Herzog, Karolin

2013-06-01

Microelectronics and microsystem technology have changed our daily lives considerably in the past 50 years. Countless everyday objects contain microelectronic components. In healthcare up to the present, however, it has not been possible to make major alterations in introducing electronics and information technology that would lead to innovative improvements and greater transparency. This paper describes initial steps in diagnostics and oncological therapy including telematic healthcare systems which can, for example, assist patients with cardiovascular diseases and shows, through these areas, how electronics and microsystems technology can contribute to better healthcare.

Effects of rapid thermal annealing on crystallinity and Sn surface segregation of {{Ge}}_{1-{\\boldsymbol{x}}}{{Sn}}_{{\\boldsymbol{x}}} films on Si (100) and Si (111)

NASA Astrophysics Data System (ADS)

Miao, Yuan-Hao; Hu, Hui-Yong; Song, Jian-Jun; Xuan, Rong-Xi; Zhang, He-Ming

2017-12-01

Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 61474085 and 61704130), the Science Research Plan in Shaanxi Province, China (Grant No. 2016GY-085), the Opening Project of Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences (Grant No. 90109162905), and the Fundamental Research Funds for the Central Universities, China (Grant No. 61704130).

Displacement Damage Effects in Solar Cells: Mining Damage From the Microelectronics and Photonics Test Bed Space Experiment

NASA Technical Reports Server (NTRS)

Hardage, Donna (Technical Monitor); Walters, R. J.; Morton, T. L.; Messenger, S. R.

2004-01-01

The objective is to develop an improved space solar cell radiation response analysis capability and to produce a computer modeling tool which implements the analysis. This was accomplished through analysis of solar cell flight data taken on the Microelectronics and Photonics Test Bed experiment. This effort specifically addresses issues related to rapid technological change in the area of solar cells for space applications in order to enhance system performance, decrease risk, and reduce cost for future missions.

Microelectronic superconducting crossover and coil

DOEpatents

Wellstood, F.C.; Kingston, J.J.; Clarke, J.

1994-03-01

A microelectronic component comprising a crossover is provided comprising a substrate, a first high T[sub c] superconductor thin film, a second insulating thin film comprising SrTiO[sub 3]; and a third high T[sub c] superconducting film which has strips which crossover one or more areas of the first superconductor film. An in situ method for depositing all three films on a substrate is provided which does not require annealing steps and which can be opened to the atmosphere between depositions. 13 figures.

Nano-interconnection for microelectronics and polymers with benzo-triazole

NASA Technical Reports Server (NTRS)

Park, Yeonjoon; Choi, Sang H.; Noh, Hyunpil; Kuk, Young

2006-01-01

Benzo-Triazole (BTA) is considered as an important bridging material that can connect an organic polymer to the metal electrode on silicon wafers as a part of the microelectronics fabrication technology. We report a detailed process of surface induced 3-D polymerization of BTA on the Cu electrode material which was measured with the Ultraviolet Photoemission Spectroscopy (UPS), X-ray Photoemission Spectroscopy (XPS), and Scanning Tunneling Microscope (STM). The electric utilization of shield and chain polymerization of BTA on Cu surface is contemplated in this study.

Photovoltaic energy converter as a chipscale high efficiency power source for implanted active microelectronic devices.

PubMed

Hwang, N-J; Patterson, W R; Song, Y-K; Atay, T; Nurmikko, A V

2004-01-01

We report the development of a microscale photovoltaic energy converter which has been designed and implemented to deliver power to CMOS-based microelectronic chips. The design targets the delivery of voltages on the order of 3V with power levels in excess of 10 mW. The geometry of the prototype device, which has been fabricated and tested, is specifically designed for coupling to an optical fiber, to facilitate remote power delivery in implantable component environment.

Inhibition of Listeria monocytogenes in Fresh Cheese Using Chitosan-Grafted Lactic Acid Packaging.

PubMed

Sandoval, Laura N; López, Monserrat; Montes-Díaz, Elizabeth; Espadín, Andres; Tecante, Alberto; Gimeno, Miquel; Shirai, Keiko

2016-04-08

A chitosan from biologically obtained chitin was successfully grafted with d,l-lactic acid (LA) in aqueous media using p-toluenesulfonic acid as catalyst to obtain a non-toxic, biodegradable packaging material that was characterized using scanning electron microscopy, water vapor permeability, and relative humidity (RH) losses. Additionally, the grafting in chitosan with LA produced films with improved mechanical properties. This material successfully extended the shelf life of fresh cheese and inhibited the growth of Listeria monocytogenes during 14 days at 4 °C and 22% RH, whereby inoculated samples with chitosan-g-LA packaging presented full bacterial inhibition. The results were compared to control samples and commercial low-density polyethylene packaging.

Thermally Conductive Tape Based on Carbon Nanotube Arrays

NASA Technical Reports Server (NTRS)

Kashani, Ali

2011-01-01

To increase contact conductance between two mating surfaces, a conductive tape has been developed by growing dense arrays of carbon nanotubes (CNTs, graphite layers folded into cylinders) on both sides of a thermally conductive metallic foil. When the two mating surfaces are brought into contact with the conductive tape in between, the CNT arrays will adhere to the mating surface. The van der Waals force between the contacting tubes and the mating surface provides adhesion between the two mating surfaces. Even though the thermal contact conductance of a single tube-to-tube contact is small, the tremendous amount of CNTs on the surface leads to a very large overall contact conductance. Interface contact thermal resistance rises from the microroughness and the macroscopic non-planar quality of mating surfaces. When two surfaces come into contact with each other, the actual contact area may be much less than the total area of the surfaces. The real area of contact depends on the load, the surface roughness, and the elastic and inelastic properties of the surface. This issue is even more important at cryogenic temperatures, where materials become hard and brittle and vacuum is used, which prevents any gas conduction through the interstitial region. A typical approach to increase thermal contact conductance is to use thermally conducting epoxies or greases, which are not always compatible with vacuum conditions. In addition, the thermal conductivities of these compounds are often relatively low. The CNTs used in this approach can be metallic or semiconducting, depending on the folding angle and diameter. The electrical resistivity of multiwalled carbon nanotubes (MWCNTs) has been reported. MWCNTs can pass a current density and remain stable at high temperatures in air. The thermal conductivity of a MWCNT at room temperature is measured to be approximately 3,000 W/m-K, which is much larger than that of diamond. At room temperature, the thermal conductance of a 0.3 sq cm array of CNTs was measured to be as high as 10 W/K. The high thermal conductivity and the nanoscale size make CNTs ideal as thermal interface materials. The CNT-based thermal tape can be used for the thermal management of microelectronic packages and electronic systems. It also can be integrated with current device technology and packaging. The material would allow for an efficient method to manage excess heat generation without requiring any additional power. Lastly, the CNT tape can be used to enhance thermal contact conductance across two mating surfaces on some NASA missions.

High-voltage solar-cell chip

NASA Technical Reports Server (NTRS)

Kapoor, V. J.; Valco, G. J.; Skebe, G. G.; Evans, J. C., Jr.

1985-01-01

Integrated circuit technology has been successfully applied to the design and fabrication of 0.5 x 0.5-cm planar multijunction solar-cell chips. Each of these solar cells consisted of six voltage-generating unit cells monolithically connected in series and fabricated on a 75-micron-thick, p-type, single crystal, silicon substrate. A contact photolithic process employing five photomask levels together with a standard microelectronics batch-processing technique were used to construct the solar-cell chip. The open-circuit voltage increased rapidly with increasing illumination up to 5 AM1 suns where it began to saturate at the sum of the individual unit-cell voltages at a maximum of 3.0 V. A short-circuit current density per unit cell of 240 mA/sq cm was observed at 10 AM1 suns.

Microsystem technology as a road from macro to nanoworld.

PubMed

Grabiec, Piotr; Domański, Krzysztof; Janus, Paweł; Zaborowski, Michał; Jaroszewicz, Bogdan

2005-04-01

Tremendous progress of microelectronic technology observed within last 40 years is closely related to even more remarkable progress of technological tools. It is important to note however, that these new tools may be used for fabrication of diverse multifunctional structures as well. Such devices, called MEMS (Micro-Electro-Mechanical-System) and MOEMS (Micro-Electro-Opto-Mechanical-System) integrate microelectronic and micromechanical structures in one system enabling interdisciplinary application, with most interesting and prospective being bio-medical investigations. Development of these applications requires however cooperation of multidisciplinary team of specialists, covering broad range of physics, (bio) chemistry and electronics, not mentioning medical doctors and other medical specialists. Thus, dissemination, of knowledge about existing processing capabilities is of key importance. In this paper, examples of various applications of microelectronic technology for fabrication of Microsystems which may be used for medicine and chemistry, will be presented. Besides, information concerning a design and technology potential available in poland and new, emerging opportunities will be given.

A stable solution-processed polymer semiconductor with record high-mobility for printed transistors

PubMed Central

Li, Jun; Zhao, Yan; Tan, Huei Shuan; Guo, Yunlong; Di, Chong-An; Yu, Gui; Liu, Yunqi; Lin, Ming; Lim, Suo Hon; Zhou, Yuhua; Su, Haibin; Ong, Beng S.

2012-01-01

Microelectronic circuits/arrays produced via high-speed printing instead of traditional photolithographic processes offer an appealing approach to creating the long-sought after, low-cost, large-area flexible electronics. Foremost among critical enablers to propel this paradigm shift in manufacturing is a stable, solution-processable, high-performance semiconductor for printing functionally capable thin-film transistors — fundamental building blocks of microelectronics. We report herein the processing and optimisation of solution-processable polymer semiconductors for thin-film transistors, demonstrating very high field-effect mobility, high on/off ratio, and excellent shelf-life and operating stabilities under ambient conditions. Exceptionally high-gain inverters and functional ring oscillator devices on flexible substrates have been demonstrated. This optimised polymer semiconductor represents a significant progress in semiconductor development, dispelling prevalent skepticism surrounding practical usability of organic semiconductors for high-performance microelectronic devices, opening up application opportunities hitherto functionally or economically inaccessible with silicon technologies, and providing an excellent structural framework for fundamental studies of charge transport in organic systems. PMID:23082244

Stored product mites (Acari: Astigmata) infesting food in various types of packaging.

PubMed

Hubert, Jan; Nesvorna, Marta; Volek, Vlado

2015-02-01

From 2008 to 2014, stored product mites have been reported from prepackaged dried food on the market in the Czech Republic. The infestation was by Carpoglyphus lactis (L.) in dried fruits and Tyrophagus putrescentiae (Schrank) in dog feed. The infestation is presumably caused by poor protection of the packages. We compared various packaging methods for their resistance to mites using dried apricots and dog feed in laboratory experiments. The trial packages included nine different plastic films, monofilm, duplex and triplex, and one type of plastic cup (ten replicates per packaging type). All packaging materials are available on the Czech market for dried food products. The samples of dried food were professionally packed in a factory and packaged dried apricots were exposed to C. lactis and dog food to T. putrescentiae. After 3 months of exposure, the infestation and mite density of the prepackaged food was assessed. Mites were found to infest six types of packages. Of the packaging types with mites, 1-5 samples were infested and the maximum abundance was 1,900 mites g(-1) of dried food. Mites entered the prepackaged food by faulty sealing. Inadequate sealing is suggested to be the major cause of the emerged infestation of dried food.

Effect of packaging materials on the chemical composition and microbiological quality of edible mushroom (Pleurotus ostreatus) grown on cassava peels.

PubMed

Ajayi, Oluwakemi; Obadina, Adewale; Idowu, Micheal; Adegunwa, Mojisola; Kajihausa, Olatundun; Sanni, Lateef; Asagbra, Yemisi; Ashiru, Bolanle; Tomlins, Keith

2015-07-01

Edible fungi such as mushrooms are highly perishable and deteriorate few days after harvest due to its high moisture content and inability to maintain their physiological status. In this study, the effect of packaging materials on the nutritional composition of mushroom cultivated from cassava peels was investigated. Mushroom samples were dried at 50°C in a cabinet dryer for 8 h. The dried mushroom samples packaged in four different packaging materials; high density polyethylene (HDPE), polypropylene (PP), laminated aluminum foil (LAF), high density polyethylene under vacuum (HDPEV) were stored at freezing (0°C) temperatures for 12 weeks. Samples were collected at 2-week intervals and analyzed for proximate composition (carbohydrate, protein, fat, fiber, ash, moisture), mineral content (calcium, potassium), vitamin C content, and microbiological qualities (total aerobic count, Pseudomonal count, Coliform count, Staphylococcal count, Salmonella count) using the standard laboratory procedures. Carbohydrate, protein, fat content of dried mushrooms packaged in HDPE at freezing temperature ranged from 45.2% to 53.5%, 18.0% to 20.3%, and 3.2% to 4.3%, while mushrooms in polypropylene ranged from 45.2% to 53.5%, 18.5% to 20.3%, 2.6% to 4.3%. Carbohydrate, protein, fat of mushroom in LAF ranged from 47.8% to 53.5%, 17.3% to 20.3%, and 3.3% to 4.3%, respectively, while carbohydrate, protein, fat of mushroom in HDPEV ranged from 51.1% to 53.5%, 19.5% to 20.3%, and 3.5% to 4.3%. Microbiological analysis showed that total aerobic count, Pseudomonal count, and Staphyloccocal count of dried mushroom ranged from 2.3 to 3.8 log cfu/g, 0.6 to 1.1 log cfu/g, and 0.4 to 0.5 log cfu/g, respectively. In conclusion, dried mushroom in HDPE packaged under vacuum at freezing temperature retained the nutritional constituents than those packaged with other packaging materials.

Effect of packaging materials on the chemical composition and microbiological quality of edible mushroom (Pleurotus ostreatus) grown on cassava peels

PubMed Central

Ajayi, Oluwakemi; Obadina, Adewale; Idowu, Micheal; Adegunwa, Mojisola; Kajihausa, Olatundun; Sanni, Lateef; Asagbra, Yemisi; Ashiru, Bolanle; Tomlins, Keith

2015-01-01

Edible fungi such as mushrooms are highly perishable and deteriorate few days after harvest due to its high moisture content and inability to maintain their physiological status. In this study, the effect of packaging materials on the nutritional composition of mushroom cultivated from cassava peels was investigated. Mushroom samples were dried at 50°C in a cabinet dryer for 8 h. The dried mushroom samples packaged in four different packaging materials; high density polyethylene (HDPE), polypropylene (PP), laminated aluminum foil (LAF), high density polyethylene under vacuum (HDPEV) were stored at freezing (0°C) temperatures for 12 weeks. Samples were collected at 2-week intervals and analyzed for proximate composition (carbohydrate, protein, fat, fiber, ash, moisture), mineral content (calcium, potassium), vitamin C content, and microbiological qualities (total aerobic count, Pseudomonal count, Coliform count, Staphylococcal count, Salmonella count) using the standard laboratory procedures. Carbohydrate, protein, fat content of dried mushrooms packaged in HDPE at freezing temperature ranged from 45.2% to 53.5%, 18.0% to 20.3%, and 3.2% to 4.3%, while mushrooms in polypropylene ranged from 45.2% to 53.5%, 18.5% to 20.3%, 2.6% to 4.3%. Carbohydrate, protein, fat of mushroom in LAF ranged from 47.8% to 53.5%, 17.3% to 20.3%, and 3.3% to 4.3%, respectively, while carbohydrate, protein, fat of mushroom in HDPEV ranged from 51.1% to 53.5%, 19.5% to 20.3%, and 3.5% to 4.3%. Microbiological analysis showed that total aerobic count, Pseudomonal count, and Staphyloccocal count of dried mushroom ranged from 2.3 to 3.8 log cfu/g, 0.6 to 1.1 log cfu/g, and 0.4 to 0.5 log cfu/g, respectively. In conclusion, dried mushroom in HDPE packaged under vacuum at freezing temperature retained the nutritional constituents than those packaged with other packaging materials. PMID:26288720

Role of DNA-DNA Interactions on the Structure and Thermodynamics of Bacteriophages Lambda and P4

PubMed Central

Petrov, Anton S.; Harvey, Stephen C.

2010-01-01

Electrostatic interactions play an important role in both packaging of DNA inside bacteriophages and its release into bacterial cells. While at physiological conditions DNA strands repel each other, the presence of polyvalent cations such as spermine and spermidine in solutions leads to the formation of DNA condensates. In this study, we discuss packaging of DNA into bacteriophages P4 and Lambda under repulsive and attractive conditions using a coarse-grained model of DNA and capsids. Packaging under repulsive conditions leads to the appearance of the coaxial spooling conformations; DNA occupies all available space inside the capsid. Under the attractive potential both packed systems reveal toroidal conformations, leaving the central part of the capsids empty. We also present a detailed thermodynamic analysis of packaging and show that the forces required to pack the genomes in the presence of polyamines are significantly lower than those observed under repulsive conditions. The analysis reveals that in both the repulsive and attractive regimes the entropic penalty of DNA confinement has a significant non-negligible contribution into the total energy of packaging. Additionally we report the results of simulations of DNA condensation inside partially packed Lambda. We found that at low densities DNA behaves as free unconfined polymer and condenses into the toroidal structures; at higher densities rearrangement of the genome into toroids becomes hindered, and condensation results in the formation of non-equilibrium structures. In all cases packaging in a specific conformation occurs as a result of interplay between bending stresses experienced by the confined polymer and interactions between the strands. PMID:21074621

Emerging epidemic in a growing industry: cigarette smoking among female micro-electronics workers in Taiwan.

PubMed

Lin, Y-P; Yen, L-L; Pan, L-Y; Chang, P-J; Cheng, T-J

2005-03-01

To explore the emerging tobacco epidemic in female workers in the growing micro-electronics industry of Taiwan. Workers were surveyed regarding their smoking status, sociodemographics and work characteristics. In total, 1950 female employees in two large micro-electronics companies in Taiwan completed the survey. Approximately 9.3% of the female employees were occasional or daily smokers at the time of the survey. The prevalence of smoking was higher in those aged 16-19 years (20.9%), those not married (12.9%), those with a high school education or less (11.7%), those employed by Company A (11.7%), shift workers (14.3%), and those who had been in their present employment for 1 year or less (13.6%). Results of multivariate adjusted logistic regression indicated that younger age, lower level of education, shorter periods of employment with the company and shift working were the important factors in determining cigarette smoking among the study participants. The odds ratio of being a daily smoker was similar to that of being a current smoker. Marital status was the only significant variable when comparing former smokers with current smokers. Smoking prevalence in female workers in the two micro-electronics companies studied was much higher than previous reports have suggested about female smoking prevalence in Taiwan and China. We suggest that smoking is no longer a 'male problem' in Taiwan. Future smoking cessation and prevention programmes should target young working women as well as men.

Implications of Pb-free microelectronics assembly in aerospace applications

NASA Technical Reports Server (NTRS)

Shapiro, A. A.; Bonner, J. K.; Ogunseitan, D.; Saphores, J. D.; Schoenung, J.

2003-01-01

The commercial microelectronics industry is rapidly moving to completely Pb-free assembly strategies within the next decade. This trend is being driven by existing and proposed legislation in Europe and in Japan. The microelectronics industry has become truly global, as indicated by major U .S. firms who already adopted Pb-free implementation programs. Among these forward-looking firms are AT&T, IBM, Motorola, HP and Intel to name a few.Following Moore's law, advances in microelectronics are happening very rapidly. In many cases, commercial industry is ahead of the aerospace sector in technology. Progress by commercial industry, along with cost, drives the use of Commercial Off-The-Shelf (COTS) parts for military and space applications. We can thus anticipate that the aerospace industry will, at some point, be forced to use Pb-free components and subsystems as part of their standard business practices. In this paper we attempt to provide a snapshot of the commercial industry trends and how they may impact electronics in the aerospace environment. In addition, we also look at different strategies for implementation. Finally we present data collected on a recent NASA project to focus on finding suitable alternatives to eutectic tin-lead solders and solder pastes. The world is moving toward implementation of environmentally friendly manufacturing techniques. The aerospace industry will be forced to deal with issues related with Pb free assembly, either by availability or legislation. This paper provides some insight into some of the tradeoffs that should be considered.

The association of alcohol outlet density with illegal underage adolescent purchasing of alcohol.

PubMed

Rowland, Bosco; Toumbourou, John W; Livingston, Michael

2015-02-01

Although previous studies have suggested that greater community densities of alcohol sales outlets are associated with greater alcohol use and problems, the mechanisms are unclear. The present study examined whether density was associated with increased purchasing of alcohol by adolescents younger than the legal purchase age of 18 in Australia. The number of alcohol outlets per 10,000 population was identified within geographic regions in Victoria, Australia. A state-representative student survey (N = 10,143) identified adolescent reports of purchasing alcohol, and multilevel modeling was then used to predict the effects for different densities of outlet types (packaged, club, on-premise, general, and overall). Each extra sales outlet per 10,000 population was associated with a significant increase in the risk of underage adolescent purchasing. The strongest effect was for club density (odds ratio = 1.22) and packaged (takeaway) outlet density (odds ratio = 1.12). Males, older children, smokers, and those with substance-using friends were more likely to purchase alcohol. One mechanism by which alcohol sales outlet density may influence population rates of alcohol use and related problems is through increasing the illegal underage purchasing of alcohol. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Scalable Sub-micron Patterning of Organic Materials Toward High Density Soft Electronics.

PubMed

Kim, Jaekyun; Kim, Myung-Gil; Kim, Jaehyun; Jo, Sangho; Kang, Jingu; Jo, Jeong-Wan; Lee, Woobin; Hwang, Chahwan; Moon, Juhyuk; Yang, Lin; Kim, Yun-Hi; Noh, Yong-Young; Jaung, Jae Yun; Kim, Yong-Hoon; Park, Sung Kyu

2015-09-28

The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. In this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. The successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics.

Architecturing hierarchical function layers on self-assembled viral templates as 3D nano-array electrodes for integrated Li-ion microbatteries.

PubMed

Liu, Yihang; Zhang, Wei; Zhu, Yujie; Luo, Yanting; Xu, Yunhua; Brown, Adam; Culver, James N; Lundgren, Cynthia A; Xu, Kang; Wang, Yuan; Wang, Chunsheng

2013-01-09

This work enables an elegant bottom-up solution to engineer 3D microbattery arrays as integral power sources for microelectronics. Thus, multilayers of functional materials were hierarchically architectured over tobacco mosaic virus (TMV) templates that were genetically modified to self-assemble in a vertical manner on current-collectors, so that optimum power and energy densities accompanied with excellent cycle-life could be achieved on a minimum footprint. The resultant microbattery based on self-aligned LiFePO(4) nanoforests of shell-core-shell structure, with precise arrangement of various auxiliary material layers including a central nanometric metal core as direct electronic pathway to current collector, delivers excellent energy density and stable cycling stability only rivaled by the best Li-ion batteries of conventional configurations, while providing rate performance per foot-print and on-site manufacturability unavailable from the latter. This approach could open a new avenue for microelectromechanical systems (MEMS) applications, which would significantly benefit from the concept that electrochemically active components be directly engineered and fabricated as an integral part of the integrated circuit (IC).

Scalable Sub-micron Patterning of Organic Materials Toward High Density Soft Electronics

NASA Astrophysics Data System (ADS)

Kim, Jaekyun; Kim, Myung-Gil; Kim, Jaehyun; Jo, Sangho; Kang, Jingu; Jo, Jeong-Wan; Lee, Woobin; Hwang, Chahwan; Moon, Juhyuk; Yang, Lin; Kim, Yun-Hi; Noh, Yong-Young; Yun Jaung, Jae; Kim, Yong-Hoon; Kyu Park, Sung

2015-09-01

The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. In this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. The successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics.

Ultracompliant Heterogeneous Copper-Tin Nanowire Arrays Making a Supersolder

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narumanchi, Sreekant V; Feng, Xuhui; Major, Joshua

Due to the substantial increase in power density, thermal interface resistance that can constitute more than 50% of the total thermal resistance has generally become a bottleneck for thermal management in electronics. However, conventional thermal interface materials (TIMs) such as solder, epoxy, gel, and grease cannot fulfill the requirements of electronics for high-power and long-term operation. Here, we demonstrate a high-performance TIM consisting of a heterogeneous copper-tin nanowire array, which we term 'supersolder' to emulate the role of conventional solders in bonding various surfaces. The supersolder is ultracompliant with a shear modulus 2-3 orders of magnitude lower than traditional soldersmore » and can reduce the thermal resistance by two times as compared with the state-of-the-art TIMs. This supersolder also exhibits excellent long-term reliability with >1200 thermal cycles over a wide temperature range. By resolving this critical thermal bottleneck, the supersolder enables electronic systems, ranging from microelectronics and portable electronics to massive data centers, to operate at lower temperatures with higher power density and reliability.« less

Particle-In-Cell Simulations of Asymmetric Dual Frequency Capacitive Discharge Physics

NASA Astrophysics Data System (ADS)

Wu, Alan; Lichtenberg, A. J.; Lieberman, M. A.; Verboncoeur, J. P.

2003-10-01

Dual frequency capacitive discharges are finding increasing use for etching in the microelectronics industry. In the ideal case, the high frequency power (typically 27.1-160 MHz) controls the plasma density and the low frequency power (typically 2-13.56 MHz) controls the ion energy. The electron power deposition and the dynamics of dual frequency rf sheaths are not well understood. We report on particle-in-cell computer simulations of an asymmetric dual frequency argon discharge. The simulations are performed in 1D (radial) geometry using the bounded electrostatic code XPDP1. Operating parameters are 27.1/2 MHz high/low frequencies, 10/13 cm inner/outer radii, 3-200 mTorr pressures, and 10^9-10^11 cm-3 densities. We determine the power deposition and sheath dynamics for the high frequency power alone, and with various added low frequency powers. We compare the simulation results to simple global models of dual frequency discharges. Support provided by Lam Research, NSF Grant ECS-0139956, California industries, and UC-SMART Contract SM99-10051.

Blending of Low-Density Polyethylene and Poly-Lactic Acid with Maleic Anhydride as A Compatibilizer for Better Environmentally Food-Packaging Material

NASA Astrophysics Data System (ADS)

Setiawan, A. H.; Aulia, F.

2017-05-01

The common conventional food packaging materialsare using a thin layer plastic or film, which is made of a synthetic polymer, such as Low-Density Poly Ethylene (LDPE). However, the use of these polymers hasan adverse impact on the environment, because the synthetic polymersare difficult to degrade naturally. Poly-Lactic Acid (PLA) is a biodegradable polymer that can be substituted to synthetic polymers. Since LDPE and PLA have a difference in polarity, therefore the first step of research is to graft them with maleic anhydride (MAH) for increasing the properties of its miscibility. The interaction between them is confirmed by FTIR; whereas the environment issueis characterized by the water adsorption and biodegradability. The FTIR spectra indicated that there had been an interaction between LDPE and MAH and LDPE/LDPE-g-MAH/PLA blend. Increasing PLA content in the blend affected to the increasing in their water absorption and biodegradable. Poly-blend with 20% PLA content was the optimum composition for environmentally food packaging.

Lumber and panel products consumption for packaging and shipping in the United States, perspective for the 1980`s

Treesearch

D. B. McKeever; H. E. Dickerhoof

Trends in demand for lumber and panel products in packaging and materials handling are examined both for the past and the future. Effects of recent technological developments and innovations such as molded particleboard pallets, medium-density fiberboard pallets, and plywood pallets, are analyzed. Increased use of pallets is seen as the main reason for the expected...

Integrated packaging of multiple double sided cooling planar bond power modules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, Zhenxian

An integrated double sided cooled power module has one or multiple phase legs configuration including one or more planar power packages, each planar power package having an upper power switch unit and a lower power switch unit directly bonded and interconnected between two insulated power substrates, and further sandwiched between two heat exchangers via direct bonds. A segmented coolant manifold is interposed with the one or more planar power packages and creates a sealed enclosure that defines a coolant inlet, a coolant outlet and a coolant flow path between the inlet and the outlet. A coolant circulates along the flowmore » path to remove heat and increase the power density of the power module.« less

Nano-engineered Multiwall Carbon Nanotube-copper Composite Thermal Interface Material for Efficient Heat Conduction

NASA Technical Reports Server (NTRS)

Ngo, Quoc; Cruden, Brett A.; Cassell, Alan M.; Sims, Gerard; Li, Jun; Meyyappa, M.; Yang, Cary Y.

2005-01-01

Efforts in integrated circuit (IC) packaging technologies have recently been focused on management of increasing heat density associated with high frequency and high density circuit designs. While current flip-chip package designs can accommodate relatively high amounts of heat density, new materials need to be developed to manage thermal effects of next-generation integrated circuits. Multiwall carbon nanotubes (MWNT) have been shown to significantly enhance thermal conduction in the axial direction and thus can be considered to be a candidate for future thermal interface materials by facilitating efficient thermal transport. This work focuses on fabrication and characterization of a robust MWNT-copper composite material as an element in IC package designs. We show that using vertically aligned MWNT arrays reduces interfacial thermal resistance by increasing conduction surface area, and furthermore, the embedded copper acts as a lateral heat spreader to efficiently disperse heat, a necessary function for packaging materials. In addition, we demonstrate reusability of the material, and the absence of residue on the contacting material, both novel features of the MWNT-copper composite that are not found in most state-of-the-art thermal interface materials. Electrochemical methods such as metal deposition and etch are discussed for the creation of the MWNT-Cu composite, detailing issues and observations with using such methods. We show that precise engineering of the composite surface affects the ability of this material to act as an efficient thermal interface material. A thermal contact resistance measurement has been designed to obtain a value of thermal contact resistance for a variety of different thermal contact materials.

Fighting blindness with microelectronics.

PubMed

Zrenner, Eberhart

2013-11-06

There is no approved cure for blindness caused by degeneration of the photoreceptor cells of the retina. However, there has been encouraging progress with attempts to restore vision using microelectronic retinal implant devices. Yet many questions remain to be addressed. Where is the best location to implant multielectrode arrays? How can spatial and temporal resolution be improved? What are the best ways to ensure the safety and longevity of these devices? Will color vision be possible? This Perspective discusses the current state of the art of retinal implants and attempts to address some of the outstanding questions.

Space, Atmospheric, and Terrestrial Radiation Environments

NASA Technical Reports Server (NTRS)

Barth, Janet L.; Dyer, C. S.; Stassinopoulos, E. G.

2003-01-01

The progress on developing models of the radiation environment since the 1960s is reviewed with emphasis on models that can be applied to predicting the performance of microelectronics used in spacecraft and instruments. Space, atmospheric, and ground environments are included. It is shown that models must be adapted continually to account for increased understanding of the dynamics of the radiation environment and the changes in microelectronics technology. The IEEE Nuclear and Space Radiation Effects Conference is a vital forum to report model progress to the radiation effects research community.

High-speed high-efficiency 500-W cw CO2 laser hermetization of metal frames of microelectronics devices

NASA Astrophysics Data System (ADS)

Levin, Andrey V.

1996-04-01

High-speed, efficient method of laser surface treatment has been developed using (500 W) cw CO2 laser. The principal advantages of CO2 laser surface treatment in comparison with solid state lasers are the basis of the method. It has been affirmed that high efficiency of welding was a consequence of the fundamental properties of metal-IR-radiation (10,6 mkm) interaction. CO2 laser hermetization of metal frames of microelectronic devices is described as an example of the proposed method application.

Using SDI-12 with ST microelectronics MCU's

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saari, Alexandra; Hinzey, Shawn Adrian; Frigo, Janette Rose

2015-09-03

ST Microelectronics microcontrollers and processors are readily available, capable and economical processors. Unfortunately they lack a broad user base like similar offerings from Texas Instrument, Atmel, or Microchip. All of these devices could be useful in economical devices for remote sensing applications used with environmental sensing. With the increased need for environmental studies, and limited budgets, flexibility in hardware is very important. To that end, and in an effort to increase open support of ST devices, I am sharing my teams' experience in interfacing a common environmental sensor communication protocol (SDI-12) with ST devices.

Crystallization Process of Superlattice-Like Sb/SiO2 Thin Films for Phase Change Memory Application

NASA Astrophysics Data System (ADS)

Zhu, Xiao-Qin; Zhang, Rui; Hu, Yi-Feng; Lai, Tian-Shu; Zhang, Jian-Hao; Zou, Hua; Song, Zhi-Tang

2018-05-01

Not Available Supported by the National Natural Science Foundation of China under Grant No 11774438, the Natural Science Foundation of Jiangsu Province under Grant No BK20151172, the Changzhou Science and Technology Bureau under Grant No CJ20160028, the Qing Lan Project, the Opening Project of State Key Laboratory of Silicon Materials under Grant No SKL2017-04, and the Opening Project of Key Laboratory of Microelectronic Devices and Integrated Technology of Institute of Microelectronics of Chinese Academy of Sciences.

Microelectronic superconducting device with multi-layer contact

DOEpatents

Wellstood, Frederick C.; Kingston, John J.; Clarke, John

1993-01-01

A microelectronic component comprising a crossover is provided comprising a substrate, a first high T.sub.c superconductor thin film, a second insulating thin film comprising SrTiO.sub.3 ; and a third high T.sub.c superconducting film which has strips which crossover one or more areas of the first superconductor film. An insitu method for depositing all three films on a substrate is provided which does not require annealing steps. The photolithographic process is used to separately pattern the high T.sub.c superconductor thin films.

A software upgrade method for micro-electronics medical implants.

PubMed

Cao, Yang; Hao, Hongwei; Xue, Lin; Li, Luming; Ma, Bozhi

2006-01-01

A software upgrade method for micro-electronics medical implants is designed to enhance the devices' function or renew the software if there are some bugs found, the software updating or some memory units disabled. The implants needn't be replaced by operations if the faults can be corrected through reprogramming, which reduces the patients' pain and improves the safety effectively. This paper introduces the software upgrade method using in-application programming (IAP) and emphasizes how to insure the system, especially the implanted part's reliability and stability while upgrading.

A Eu/Tb-mixed MOF for luminescent high-temperature sensing

NASA Astrophysics Data System (ADS)

Wang, Huizhen; Zhao, Dian; Cui, Yuangjing; Yang, Yu; Qian, Guodong

2017-02-01

Temperature measurements and thermal mapping using luminescent MOF operating in the high-temperature range are of great interest in the micro-electronic diagnosis. In this paper, we report a thermostable Eu/Tb-mixed MOF Eu0.37Tb0.63-BTC-a exhibiting strong luminescence at elevated temperature, which can serve as a ratiometric luminescent thermometer for high-temperature range. The high-temperature operating range (313-473 K), high relative sensitivity and accurate temperature resolution, make such a Eu/Tb-mixed MOF useful for micro-electronic diagnosis.

Microelectronic superconducting device with multi-layer contact

DOEpatents

Wellstood, F.C.; Kingston, J.J.; Clarke, J.

1993-10-26

A microelectronic component comprising a crossover is provided comprising a substrate, a first high T[sub c] superconductor thin film, a second insulating thin film comprising SrTiO[sub 3] ; and a third high T[sub c] superconducting film which has strips which crossover one or more areas of the first superconductor film. An in situ method for depositing all three films on a substrate is provided which does not require annealing steps. The photolithographic process is used to separately pattern the high T[sub c] superconductor thin films. 14 figures.

Hydrogen ion microlithography

DOEpatents

Tsuo, Y. Simon; Deb, Satyen K.

1990-01-01

Disclosed is a hydrogen ion microlithography process for use in microelectronic fabrication and semiconductor device processing. The process comprises the steps of providing a single layer of either an amorphous silicon or hydrogenated amorphous silicon material. A pattern is recorded in a selected layer of amorphous silicon or hydrogenated amorphous silicon materials by preferentially implanting hydrogen ions therein so as to permit the selected layer to serve as a mask-resist wafer suitable for subsequent development and device fabrication. The layer is developed to provide a surface pattern therein adaptable for subsequent use in microelectronic fabrication and semiconductor device processing.

Test report dot 7A type a liquid packaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ketusky, E. T.; Brandjes, C.; Benoit, T. J.

This test report documents the performance of Savannah River National Laboratory’s (SRNL’s) U.S. Department of Transportation (DOT) Specification 7A; General Packaging, Type A shielded liquid shipping packaging and compliance with the regulatory requirements of Title 49 of the Code of Federal Regulations (CFR). The primary use of this packaging design is for the transport of radioactive liquids of up to 1.3 liters in an unshielded configuration and up to 113 mL of radioactive liquids in a shielded configuration, with no more than an A2 quantity in either configuration, over public highways and/or commercial aircraft. The contents are liquid radioactive materialsmore » sufficiently shielded and within the activity limits specified in173.435 or 173.433 for A2 (normal form) materials, as well as within the analyzed thermal heat limits. Any contents must be compatibly packaged and must be compatible with the packaging. The basic packaging design is based on the U.S. Department of Energy’s (DOE’s) Model 9979 Type A fissile shipping packaging designed and tested by SRNL. The shielded liquid configuration consists of the outer and inner drums of the 9979 package with additional low density polyethylene (LDPE) dunnage nesting a tungsten shielded cask assembly (WSCA) within the 30-gallon inner drum. The packaging model for the DOT Specification 7A, Type A liquids packaging is HVYTAL.« less

PAREMD: A parallel program for the evaluation of momentum space properties of atoms and molecules

NASA Astrophysics Data System (ADS)

Meena, Deep Raj; Gadre, Shridhar R.; Balanarayan, P.

2018-03-01

The present work describes a code for evaluating the electron momentum density (EMD), its moments and the associated Shannon information entropy for a multi-electron molecular system. The code works specifically for electronic wave functions obtained from traditional electronic structure packages such as GAMESS and GAUSSIAN. For the momentum space orbitals, the general expression for Gaussian basis sets in position space is analytically Fourier transformed to momentum space Gaussian basis functions. The molecular orbital coefficients of the wave function are taken as an input from the output file of the electronic structure calculation. The analytic expressions of EMD are evaluated over a fine grid and the accuracy of the code is verified by a normalization check and a numerical kinetic energy evaluation which is compared with the analytic kinetic energy given by the electronic structure package. Apart from electron momentum density, electron density in position space has also been integrated into this package. The program is written in C++ and is executed through a Shell script. It is also tuned for multicore machines with shared memory through OpenMP. The program has been tested for a variety of molecules and correlated methods such as CISD, Møller-Plesset second order (MP2) theory and density functional methods. For correlated methods, the PAREMD program uses natural spin orbitals as an input. The program has been benchmarked for a variety of Gaussian basis sets for different molecules showing a linear speedup on a parallel architecture.

Microbial barrier assessment of Tyvek stopper packaging for rubber closures.

PubMed

Moldenhauer, J E; Bass, S A; Kupinski, M J; Walters, M L; Rubio, S L

1996-01-01

Two types of Tyvek and high density polyethylene or polypropylene packaging used for sterilization of rubber closures were evaluated for Microbial Barrier properties. The packaging evaluated was "Ready to Sterilize" (1) stoppers and a second test package (Test 2) which was designated as appropriate for a clean room, filled with washed and siliconized stoppers and then heat sealed. Each type of packaging was subjected to three different sterilization temperatures (125 degrees C, 128 degrees C and 131 degrees C) in a production sterilizer (15-18 psi). Following sterilization, a microbial barrier assessment was performed, using Bacillus subtilis niger (ATCC 9372), to determine whether the packaging could maintain a sterile barrier following sterilization. Results of the testing indicated that a microbial barrier was maintained for products in "Ready to Sterilize" packages at 125 degrees C and 128 degrees C. For products sterilized in the Test 2 container a microbial barrier could not be maintained at 128 degrees C, and no further testing was performed. Following sterilization at 131 degrees C physical defects were noted for the "Ready to Sterilize" bag and a microbial barrier could not be maintained.

Effectiveness of antimicrobial food packaging materials.

PubMed

Cooksey, K

2005-10-01

Antimicrobial additives have been used successfully for many years as direct food additives. The literature provides evidence that some of these additives may be effective as indirect food additives incorporated into food packaging materials. Antimicrobial food packaging is directed toward the reduction of surface contamination of processed, prepared foods such as sliced meats and Frankfurter sausages (hot dogs). The use of such packaging materials is not meant to be a substitute for good sanitation practices, but it should enhance the safety of food as an additional hurdle for the growth of pathogenic and/or spoilage microorganisms. Studies have focused on establishing methods for coating low-density polyethylene film or barrier films with methyl cellulose as a carrier for nisin. These films have significantly reduced the presence of Listeria monocytogenes in solutions and in vacuum packaged hot dogs. Other research has focused on the use of chitosan to inhibit L. monocytogenes and chlorine dioxide sachets for the reduction of Salmonella on modified atmosphere-packaged fresh chicken breasts. Overall, antimicrobial packaging shows promise as an effective method for the inhibition of certain bacteria in foods, but barriers to their commercial implementation continue to exist.

DNA Packaging in Bacteriophage: Is Twist Important?

PubMed Central

Spakowitz, Andrew James; Wang, Zhen-Gang

2005-01-01

We study the packaging of DNA into a bacteriophage capsid using computer simulation, specifically focusing on the potential impact of twist on the final packaged conformation. We perform two dynamic simulations of packaging a polymer chain into a spherical confinement: one where the chain end is rotated as it is fed, and one where the chain is fed without end rotation. The final packaged conformation exhibits distinct differences in these two cases: the packaged conformation from feeding with rotation exhibits a spool-like character that is consistent with experimental and previous theoretical work, whereas feeding without rotation results in a folded conformation inconsistent with a spool conformation. The chain segment density shows a layered structure, which is more pronounced for packaging with rotation. However, in both cases, the conformation is marked by frequent jumps of the polymer chain from layer to layer, potentially influencing the ability to disentangle during subsequent ejection. Ejection simulations with and without Brownian forces show that Brownian forces are necessary to achieve complete ejection of the polymer chain in the absence of external forces. PMID:15805174

DNA packaging in bacteriophage: is twist important?

PubMed

Spakowitz, Andrew James; Wang, Zhen-Gang

2005-06-01

We study the packaging of DNA into a bacteriophage capsid using computer simulation, specifically focusing on the potential impact of twist on the final packaged conformation. We perform two dynamic simulations of packaging a polymer chain into a spherical confinement: one where the chain end is rotated as it is fed, and one where the chain is fed without end rotation. The final packaged conformation exhibits distinct differences in these two cases: the packaged conformation from feeding with rotation exhibits a spool-like character that is consistent with experimental and previous theoretical work, whereas feeding without rotation results in a folded conformation inconsistent with a spool conformation. The chain segment density shows a layered structure, which is more pronounced for packaging with rotation. However, in both cases, the conformation is marked by frequent jumps of the polymer chain from layer to layer, potentially influencing the ability to disentangle during subsequent ejection. Ejection simulations with and without Brownian forces show that Brownian forces are necessary to achieve complete ejection of the polymer chain in the absence of external forces.

Experimental Durability Testing of 4H SiC JFET Integrated Circuit Technology at 727 C

NASA Technical Reports Server (NTRS)

Spry, David; Neudeck, Phil; Chen, Liangyu; Chang, Carl; Lukco, Dorothy; Beheim, Glenn M

2016-01-01

We have reported SiC integrated circuits (IC's) with two levels of metal interconnect that have demonstrated prolonged operation for thousands of hours at their intended peak ambient operational temperature of 500 C [1, 2]. However, it is recognized that testing of semiconductor microelectronics at temperatures above their designed operating envelope is vital to qualification. Towards this end, we previously reported operation of a 4H-SiC JFET IC ring oscillator on an initial fast thermal ramp test through 727 C [3]. However, this thermal ramp was not ended until a peak temperature of 880 C (well beyond failure) was attained. Further experiments are necessary to better understand failure mechanisms and upper temperature limit of this extreme-temperature capable 4H-SiC IC technology. Here we report on additional experimental testing of custom-packaged 4H-SiC JFET IC devices at temperatures above 500 C. In one test, the temperature was ramped and then held at 727 C, and the devices were periodically measured until electrical failure was observed. A 4H-SiC JFET on this chip electrically functioned with little change for around 25 hours at 727 C before rapid increases in device resistance caused failure. In a second test, devices from our next generation 4H-SiC JFET ICs were ramped up and then held at 700 C (which is below the maximum deposition temperature of the dielectrics). Three ring oscillators functioned for 8 hours at this temperature before degradation. In a third experiment, an alternative die attach of gold paste and package lid was used, and logic circuit operation was demonstrated for 143.5 hours at 700 C.

Experimental Durability Testing of 4H SiC JFET Integrated Circuit Technology at 727 Degrees Centigrade

NASA Technical Reports Server (NTRS)

Spry, David J.; Neudeck, Philip G.; Chen, Liangyu; Chang, Carl W.; Lukco, Dorothy; Beheim, Glenn M.

2016-01-01

We have reported SiC integrated circuits (ICs) with two levels of metal interconnect that have demonstrated prolonged operation for thousands of hours at their intended peak ambient operational temperature of 500 degrees Centigrade. However, it is recognized that testing of semiconductor microelectronics at temperatures above their designed operating envelope is vital to qualification. Towards this end, we previously reported operation of a 4H-SiC JFET IC ring oscillator on an initial fast thermal ramp test through 727 degrees Centigrade. However, this thermal ramp was not ended until a peak temperature of 880 degrees Centigrade (well beyond failure) was attained. Further experiments are necessary to better understand failure mechanisms and upper temperature limit of this extreme-temperature capable 4H-SiC IC technology.Here we report on additional experimental testing of custom-packaged 4H-SiC JFET IC devices at temperatures above 500 degrees Centigrade. In one test, the temperature was ramped and then held at 727 degrees Centigrade, and the devices were periodically measured until electrical failure was observed. A 4H-SiC JFET on this chip electrically functioned with little change for around 25 hours at 727 degrees Centigrade before rapid increases in device resistance caused failure. In a second test, devices from our next generation 4H-SiC JFET ICs were ramped up and then held at 700 degrees Centigrade (which is below the maximum deposition temperature of the dielectrics). Three ring oscillators functioned for 8 hours at this temperature before degradation. In a third experiment, an alternative die attach of gold paste and package lid was used, and logic circuit operation was demonstrated for 143.5 hours at 700 degrees Centigrade.

Fabrication of Fresnel micro lens array in borosilicate glass by F2-laser ablation for glass interposer application

NASA Astrophysics Data System (ADS)

Brusberg, Lars; Neitz, Marcel; Schröder, Henning; Fricke-Begemann, Thomas; Ihlemann, Jürgen

2014-03-01

The future need for more bandwidth forces the development of optical transmission solutions for rack-to-rack, boardto- board and chip-to-chip interconnects. The goals are significant reduction of power consumption, highest density and potential for bandwidth scalability to overcome the limitations of the systems today with mostly copper based interconnects. For system integration the enabling of thin glass as a substrate material for electro-optical components with integrated micro-optics for efficient light coupling to integrated optical waveguides or fibers is becoming important. Our glass based packaging approach merges micro-system packaging and glass integrated optics. This kind of packaging consists of a thin glass substrate with integrated micro lenses providing a platform for photonic component assembly and optical fiber or waveguide interconnection. Thin glass is commercially available in panel and wafer size and characterizes excellent optical and high frequency properties. That makes it perfect for microsystem packaging. A suitable micro lens approach has to be comparable with different commercial glasses and withstand post-processing like soldering. A benefit of using laser ablated Fresnel lenses is the planar integration capability in the substrate for highest integration density. In the paper we introduce our glass based packaging concept and the Fresnel lens design for different scenarios like chip-to-fiber, chip-to-optical-printed-circuit-board coupling. Based on the design the Fresnel lenses were fabricated by using a 157 nm fluorine laser ablation system.

Effectiveness of some recent antimicrobial packaging concepts.

PubMed

Vermeiren, L; Devlieghere, F; Debevere, J

2002-01-01

A new type of active packaging is the combination of food-packaging materials with antimicrobial substances to control microbial surface contamination of foods. For both migrating and non-migrating antimicrobial materials, intensive contact between the food product and packaging material is required and therefore potential food applications include especially vacuum or skin-packaged products, e.g. vacuum-packaged meat, fish, poultry or cheese. Several antimicrobial compounds have been combined with different types of carriers (plastic and rubber articles, paper-based materials, textile fibrils and food-packaging materials). Until now, however, few antimicrobial concepts have found applications as a food-packaging material. Antimicrobial packaging materials cannot legally be used in the EU at the moment. The potential use would require amendments of several different legal texts involving areas such as food additives, food packaging, hygiene, etc. The main objective of this paper is to provide a state of the art about the different types of antimicrobial concepts, their experimental development and commercialization, and to present a case study summarizing the results of investigations on the feasibility of a low-density polyethylene (LDPE)-film containing triclosan to inhibit microbial growth on food surfaces and consequently prolong shelf-life or improve microbial food safety. In contrast with the strong antimicrobial effect in in-vitro simulated vacuum-packaged conditions against the psychrotrophic food pathogen L. monocytogenes, the 1000 mg kg(-1) containing triclosan film did not effectively reduce spoilage bacteria and growth of L. monocytogenes on refrigerated vacuum-packaged chicken breasts stored at 7 degrees C.

BOK-Printed Electronics

NASA Technical Reports Server (NTRS)

Ghaffarian, Reza

2013-01-01

The use of printed electronics technologies (PETs), 2D or 3D printing approaches either by conventional electronic fabrication or by rapid graphic printing of organic or nonorganic electronic devices on various small or large rigid or flexible substrates, is projected to grow exponentially in commercial industry. This has provided an opportunity to determine whether or not PETs could be applicable for low volume and high-reliability applications. This report presents a summary of literature surveyed and provides a body of knowledge (BOK) gathered on the current status of organic and printed electronics technologies. It reviews three key industry roadmaps- on this subject-OE-A, ITRS, and iNEMI-each with a different name identification for this emerging technology. This followed by a brief review of the status of the industry on standard development for this technology, including IEEE and IPC specifications. The report concludes with key technologies and applications and provides a technology hierarchy similar to those of conventional microelectronics for electronics packaging. Understanding key technology roadmaps, parameters, and applications is important when judicially selecting and narrowing the follow-up of new and emerging applicable technologies for evaluation, as well as the low risk insertion of organic, large area, and printed electronics.

Silicon microelectronic field-emissive devices for advanced display technology

NASA Astrophysics Data System (ADS)

Morse, J. D.

1993-03-01

Field-emission displays (FED's) offer the potential advantages of high luminous efficiency, low power consumption, and low cost compared to AMLCD or CRT technologies. An LLNL team has developed silicon-point field emitters for vacuum triode structures and has also used thin-film processing techniques to demonstrate planar edge-emitter configurations. LLNL is interested in contributing its experience in this and other FED-related technologies to collaborations for commercial FED development. At LLNL, FED development is supported by computational capabilities in charge transport and surface/interface modeling in order to develop smaller, low-work-function field emitters using a variety of materials and coatings. Thin-film processing, microfabrication, and diagnostic/test labs permit experimental exploration of emitter and resistor structures. High field standoff technology is an area of long-standing expertise that guides development of low-cost spacers for FEDS. Vacuum sealing facilities are available to complete the FED production engineering process. Drivers constitute a significant fraction of the cost of any flat-panel display. LLNL has an advanced packaging group that can provide chip-on-glass technologies and three-dimensional interconnect generation permitting driver placement on either the front or the back of the display substrate.

PREFACE: MicroTherm' 2013 - Microtechnology and Thermal Problems in Electronics

NASA Astrophysics Data System (ADS)

Lisik, Zbigniew; Raj, Ewa

2014-04-01

MicroTherm is an International Conference on Microtechnology and Thermal Problems in Electronics organised as a cyclic event since 1996. The success of the first seminar, which was devoted mainly to thermal management aspects, and the successive conferences have led us to the tenth edition. Since the first meeting, the scope of the conference has expanded, following the progress of electronics. Now, it covers subjects connected with extreme temperature, electronics, sensors and measurement techniques, modelling, simulation, wide band-gap materials, packaging and reliability, renewable energy sources and photonics with special emphasis on microelectronic technologies. MicroTherm' 2013 was held in Lodz, Poland, on 25-28 June 2013. The programme consistied of invited talks and nine regular sessions in the form of planar discussions and poster presentations, including a Students' Session. The Students' session gave an opportunity for students and young researchers to present their first achievements in the field of science. The next MicroTherm Conference is going to be held on 22-25 June 2015, in Lodz — a beautiful, post-industrial city located in the centre of Poland. Please, feel invited to MicroTherm' 2015 (www.microtherm.dsod.pl). Ewa Raj and Zbigniew Lisik Editors

Restoring visual perception using microsystem technologies: engineering and manufacturing perspectives.

PubMed

Krisch, I; Hosticka, B J

2007-01-01

Microsystem technologies offer significant advantages in the development of neural prostheses. In the last two decades, it has become feasible to develop intelligent prostheses that are fully implantable into the human body with respect to functionality, complexity, size, weight, and compactness. Design and development enforce collaboration of various disciplines including physicians, engineers, and scientists. The retina implant system can be taken as one sophisticated example of a prosthesis which bypasses neural defects and enables direct electrical stimulation of nerve cells. This micro implantable visual prosthesis assists blind patients to return to the normal course of life. The retina implant is intended for patients suffering from retinitis pigmentosa or macular degeneration. In this contribution, we focus on the epiretinal prosthesis and discuss topics like system design, data and power transfer, fabrication, packaging and testing. In detail, the system is based upon an implantable micro electro stimulator which is powered and controlled via a wireless inductive link. Microelectronic circuits for data encoding and stimulation are assembled on flexible substrates with an integrated electrode array. The implant system is encapsulated using parylene C and silicone rubber. Results extracted from experiments in vivo demonstrate the retinotopic activation of the visual cortex.

Ultralow-k nanoporous organosilicate dielectric films imprinted with dendritic spheres.

PubMed

Lee, Byeongdu; Park, Young-Hee; Hwang, Yong-Taek; Oh, Weontae; Yoon, Jinhwan; Ree, Moonhor

2005-02-01

Integrated circuits that have improved functionality and speed in a smaller package and that consume less power are desired by the microelectronics industry as well as by end users, to increase device performance and reduce costs. The fabrication of high-performance integrated circuits requires the availability of materials with low or ultralow dielectric constant (low-k: k

Layer by layer assembly of a biocatalytic packaging film: lactase covalently bound to low-density polyethylene.

PubMed

Wong, Dana E; Talbert, Joey N; Goddard, Julie M

2013-06-01

Active packaging is utilized to overcome limitations of traditional processing to enhance the health, safety, economics, and shelf life of foods. Active packaging employs active components to interact with food constituents to give a desired effect. Herein we describe the development of an active package in which lactase is covalently attached to low-density polyethylene (LDPE) for in-package production of lactose-free dairy products. The specific goal of this work is to increase the total protein content loading onto LDPE using layer by layer (LbL) deposition, alternating polyethylenimine, glutaraldehyde (GL), and lactase, to enhance the overall activity of covalently attached lactase. The films were successfully oxidized via ultraviolet light, functionalized with polyethylenimine and glutaraldehyde, and layered with immobilized purified lactase. The total protein content increased with each additional layer of conjugated lactase, the 5-layer sample reaching up to 1.3 μg/cm2 . However, the increase in total protein did not lend to an increase in overall lactase activity. Calculated apparent Km indicated the affinity of immobilized lactase to substrate remains unchanged when compared to free lactase. Calculated apparent turnover numbers (kcat ) showed with each layer of attached lactase, a decrease in substrate turnover was experienced when compared to free lactase; with a decrease from 128.43 to 4.76 s(-1) for a 5-layer conjugation. Our results indicate that while LbL attachment of lactase to LDPE successfully increases total protein mass of the bulk material, the adverse impact in enzyme efficiency may limit the application of LbL immobilization chemistry for bioactive packaging use. © 2013 Institute of Food Technologists®

Job stress models, depressive disorders and work performance of engineers in microelectronics industry.

PubMed

Chen, Sung-Wei; Wang, Po-Chuan; Hsin, Ping-Lung; Oates, Anthony; Sun, I-Wen; Liu, Shen-Ing

2011-01-01

Microelectronic engineers are considered valuable human capital contributing significantly toward economic development, but they may encounter stressful work conditions in the context of a globalized industry. The study aims at identifying risk factors of depressive disorders primarily based on job stress models, the Demand-Control-Support and Effort-Reward Imbalance models, and at evaluating whether depressive disorders impair work performance in microelectronics engineers in Taiwan. The case-control study was conducted among 678 microelectronics engineers, 452 controls and 226 cases with depressive disorders which were defined by a score 17 or more on the Beck Depression Inventory and a psychiatrist's diagnosis. The self-administered questionnaires included the Job Content Questionnaire, Effort-Reward Imbalance Questionnaire, demography, psychosocial factors, health behaviors and work performance. Hierarchical logistic regression was applied to identify risk factors of depressive disorders. Multivariate linear regressions were used to determine factors affecting work performance. By hierarchical logistic regression, risk factors of depressive disorders are high demands, low work social support, high effort/reward ratio and low frequency of physical exercise. Combining the two job stress models may have better predictive power for depressive disorders than adopting either model alone. Three multivariate linear regressions provide similar results indicating that depressive disorders are associated with impaired work performance in terms of absence, role limitation and social functioning limitation. The results may provide insight into the applicability of job stress models in a globalized high-tech industry considerably focused in non-Western countries, and the design of workplace preventive strategies for depressive disorders in Asian electronics engineering population.

Compact electro-optical module with polymer waveguides on a flexible substrate for high-density board-level communication

NASA Astrophysics Data System (ADS)

Weiss, J. R. M.; Lamprecht, T.; Meier, N.; Dangel, R.; Horst, F.; Jubin, D.; Beyeler, R.; Offrein, B. J.

2010-02-01

We report on the co-packaging of electrical CMOS transceiver and VCSEL chip arrays on a flexible electrical substrate with optical polymer waveguides. The electro-optical components are attached to the substrate edge and butt-coupled to the waveguides. Electrically conductive silver-ink connects them to the substrate at an angle of 90°. The final assembly contacts the surface of a package laminate with an integrated compressible connector. The module can be folded to save space, requires only a small footprint on the package laminate and provides short electrical high-speed signal paths. With our approach, the electro-optical package becomes a compact electro-optical module with integrated polymer waveguides terminated with either optical connectors (e.g., at the card edge) or with an identical assembly for a second processor on the board. Consequently, no costly subassemblies and connectors are needed, and a very high integration density and scalability to virtually arbitrary channel counts and towards very high data rates (20+ Gbps) become possible. Future cost targets of much less than US$1 per Gbps will be reached by employing standard PCB materials and technologies that are well established in the industry. Moreover, our technology platform has both electrical and optical connectivity and functionality.

Monolayer Boron Nitride Substrate Interactions with Graphene Under In-Plane and Perpendicular Strains: A First-Principles Study

NASA Astrophysics Data System (ADS)

Behzad, Somayeh

2018-04-01

Effects of strain on the electronic and optical properties of graphene on monolayer boron nitride (BN) substrate are investigated using first-principle calculations based on density functional theory. Strain-free graphene/BN has a small band gap of 97 meV at the K point. The magnitude of band gap increases with in-plane biaxial strain while it decreases with the perpendicular uniaxial strain. The ɛ2 (ω ) spectrum of graphene/BN bilayer for parallel polarization shows red and blue shifts by applying the in-plane tensile and compressive strains, respectively. Also the positions of peaks in the ɛ2 (ω ) spectrum are not significantly changed under perpendicular strain. The calculated results indicate that graphene on the BN substrate has great potential in microelectronic and optoelectronic applications.

GeNeDA: An Open-Source Workflow for Design Automation of Gene Regulatory Networks Inspired from Microelectronics.

PubMed

Madec, Morgan; Pecheux, François; Gendrault, Yves; Rosati, Elise; Lallement, Christophe; Haiech, Jacques

2016-10-01

The topic of this article is the development of an open-source automated design framework for synthetic biology, specifically for the design of artificial gene regulatory networks based on a digital approach. In opposition to other tools, GeNeDA is an open-source online software based on existing tools used in microelectronics that have proven their efficiency over the last 30 years. The complete framework is composed of a computation core directly adapted from an Electronic Design Automation tool, input and output interfaces, a library of elementary parts that can be achieved with gene regulatory networks, and an interface with an electrical circuit simulator. Each of these modules is an extension of microelectronics tools and concepts: ODIN II, ABC, the Verilog language, SPICE simulator, and SystemC-AMS. GeNeDA is first validated on a benchmark of several combinatorial circuits. The results highlight the importance of the part library. Then, this framework is used for the design of a sequential circuit including a biological state machine.

Microelectronics Revolution And The Impact Of Automation In The New Industrialized Countries

NASA Astrophysics Data System (ADS)

Baranauskas, Vitor

1984-08-01

A brief review of some important historical points on the origin of the Factories and the Industrial Revolution is presented with emphasis in the social problems related to the automation of the human labor. Until the World War I, the social changes provoked by the Industrial Revolution caused one division of the World in developed and underdeveloped countries. After that period, the less developed nations began their industrialization mainly through the Multinationals Corporations (MC). These enterprises were very important to the production and exportation of utilities and manufactures in general, mainly in those products which required intensive and direct human labor. At present time, with the pervasiveness of microelectronics in the automation, this age seems to reaching an end because all continous processes in industry tend economicaly toward total automation. This fact will cause a retraction in long-term investments and, beyond massive unemployment, there is a tendency for these MC industries to return to their original countries. The most promising alternative to avoid these events, and perhaps the unique, is to incentive an autonomous development in areas of high technology, as for instance, the microelectronics itself.

Chip-package nano-structured copper and nickel interconnections with metallic and polymeric bonding interfaces

NASA Astrophysics Data System (ADS)

Aggarwal, Ankur

With the semiconductor industry racing toward a historic transition, nano chips with less than 45 nm features demand I/Os in excess of 20,000 that support computing speed in terabits per second, with multi-core processors aggregately providing highest bandwidth at lowest power. On the other hand, emerging mixed signal systems are driving the need for 3D packaging with embedded active components and ultra-short interconnections. Decreasing I/O pitch together with low cost, high electrical performance and high reliability are the key technological challenges identified by the 2005 International Technology Roadmap for Semiconductors (ITRS). Being able to provide several fold increase in the chip-to-package vertical interconnect density is essential for garnering the true benefits of nanotechnology that will utilize nano-scale devices. Electrical interconnections are multi-functional materials that must also be able to withstand complex, sustained and cyclic thermo-mechanical loads. In addition, the materials must be environmentally-friendly, corrosion resistant, thermally stable over a long time, and resistant to electro-migration. A major challenge is also to develop economic processes that can be integrated into back end of the wafer foundry, i.e. with wafer level packaging. Device-to-system board interconnections are typically accomplished today with either wire bonding or solders. Both of these are incremental and run into either electrical or mechanical barriers as they are extended to higher density of interconnections. Downscaling traditional solder bump interconnect will not satisfy the thermo-mechanical reliability requirements at very fine pitches of the order of 30 microns and less. Alternate interconnection approaches such as compliant interconnects typically require lengthy connections and are therefore limited in terms of electrical properties, although expected to meet the mechanical requirements. A novel chip-package interconnection technology is developed to address the IC packaging requirements beyond the ITRS projections and to introduce innovative design and fabrication concepts that will further advance the performance of the chip, the package, and the system board. The nano-structured interconnect technology simultaneously packages all the ICs intact in wafer form with quantum jump in the number of interconnections with the lowest electrical parasitics. The intrinsic properties of nano materials also enable several orders of magnitude higher interconnect densities with the best mechanical properties for the highest reliability and yet provide higher current and heat transfer densities. Nano-structured interconnects provides the ability to assemble the packaged parts on the system board without the use of underfill materials and to enable advanced analog/digital testing, reliability testing, and burn-in at wafer level. This thesis investigates the electrical and mechanical performance of nanostructured interconnections through modeling and test vehicle fabrication. The analytical models evaluate the performance improvements over solder and compliant interconnections. Test vehicles with nano-interconnections were fabricated using low cost electro-deposition techniques and assembled with various bonding interfaces. Interconnections were fabricated at 200 micron pitch to compare with the existing solder joints and at 50 micron pitch to demonstrate fabrication processes at fine pitches. Experimental and modeling results show that the proposed nano-interconnections could enhance the reliability and potentially meet all the system performance requirements for the emerging micro/nano-systems.

DensToolKit: A comprehensive open-source package for analyzing the electron density and its derivative scalar and vector fields

NASA Astrophysics Data System (ADS)

Solano-Altamirano, J. M.; Hernández-Pérez, Julio M.

2015-11-01

DensToolKit is a suite of cross-platform, optionally parallelized, programs for analyzing the molecular electron density (ρ) and several fields derived from it. Scalar and vector fields, such as the gradient of the electron density (∇ρ), electron localization function (ELF) and its gradient, localized orbital locator (LOL), region of slow electrons (RoSE), reduced density gradient, localized electrons detector (LED), information entropy, molecular electrostatic potential, kinetic energy densities K and G, among others, can be evaluated on zero, one, two, and three dimensional grids. The suite includes a program for searching critical points and bond paths of the electron density, under the framework of Quantum Theory of Atoms in Molecules. DensToolKit also evaluates the momentum space electron density on spatial grids, and the reduced density matrix of order one along lines joining two arbitrary atoms of a molecule. The source code is distributed under the GNU-GPLv3 license, and we release the code with the intent of establishing an open-source collaborative project. The style of DensToolKit's code follows some of the guidelines of an object-oriented program. This allows us to supply the user with a simple manner for easily implement new scalar or vector fields, provided they are derived from any of the fields already implemented in the code. In this paper, we present some of the most salient features of the programs contained in the suite, some examples of how to run them, and the mathematical definitions of the implemented fields along with hints of how we optimized their evaluation. We benchmarked our suite against both a freely-available program and a commercial package. Speed-ups of ˜2×, and up to 12× were obtained using a non-parallel compilation of DensToolKit for the evaluation of fields. DensToolKit takes similar times for finding critical points, compared to a commercial package. Finally, we present some perspectives for the future development and growth of the suite.

Packaging Technologies for 500 C SiC Electronics and Sensors: Challenges in Material Science and Technology

NASA Technical Reports Server (NTRS)

Chen, Liang-Yu; Neudeck, Philip G.; Behelm, Glenn M.; Spry, David J.; Meredith, Roger D.; Hunter, Gary W.

2015-01-01

This paper presents ceramic substrates and thick-film metallization based packaging technologies in development for 500C silicon carbide (SiC) electronics and sensors. Prototype high temperature ceramic chip-level packages and printed circuit boards (PCBs) based on ceramic substrates of aluminum oxide (Al2O3) and aluminum nitride (AlN) have been designed and fabricated. These ceramic substrate-based chip-level packages with gold (Au) thick-film metallization have been electrically characterized at temperatures up to 550C. The 96 alumina packaging system composed of chip-level packages and PCBs has been successfully tested with high temperature SiC discrete transistor devices at 500C for over 10,000 hours. In addition to tests in a laboratory environment, a SiC junction field-effect-transistor (JFET) with a packaging system composed of a 96 alumina chip-level package and an alumina printed circuit board was tested on low earth orbit for eighteen months via a NASA International Space Station experiment. In addition to packaging systems for electronics, a spark-plug type sensor package based on this high temperature interconnection system for high temperature SiC capacitive pressure sensors was also developed and tested. In order to further significantly improve the performance of packaging system for higher packaging density, higher operation frequency, power rating, and even higher temperatures, some fundamental material challenges must be addressed. This presentation will discuss previous development and some of the challenges in material science (technology) to improve high temperature dielectrics for packaging applications.

Calculations with off-shell matrix elements, TMD parton densities and TMD parton showers

NASA Astrophysics Data System (ADS)

Bury, Marcin; van Hameren, Andreas; Jung, Hannes; Kutak, Krzysztof; Sapeta, Sebastian; Serino, Mirko

2018-02-01

A new calculation using off-shell matrix elements with TMD parton densities supplemented with a newly developed initial state TMD parton shower is described. The calculation is based on the KaTie package for an automated calculation of the partonic process in high-energy factorization, making use of TMD parton densities implemented in TMDlib. The partonic events are stored in an LHE file, similar to the conventional LHE files, but now containing the transverse momenta of the initial partons. The LHE files are read in by the Cascade package for the full TMD parton shower, final state shower and hadronization from Pythia where events in HEPMC format are produced. We have determined a full set of TMD parton densities and developed an initial state TMD parton shower, including all flavors following the TMD distribution. As an example of application we have calculated the azimuthal de-correlation of high p_t dijets as measured at the LHC and found very good agreement with the measurement when including initial state TMD parton showers together with conventional final state parton showers and hadronization.

Calculations with off-shell matrix elements, TMD parton densities and TMD parton showers.

PubMed

Bury, Marcin; van Hameren, Andreas; Jung, Hannes; Kutak, Krzysztof; Sapeta, Sebastian; Serino, Mirko

2018-01-01

A new calculation using off-shell matrix elements with TMD parton densities supplemented with a newly developed initial state TMD parton shower is described. The calculation is based on the KaTie package for an automated calculation of the partonic process in high-energy factorization, making use of TMD parton densities implemented in TMDlib. The partonic events are stored in an LHE file, similar to the conventional LHE files, but now containing the transverse momenta of the initial partons. The LHE files are read in by the Cascade package for the full TMD parton shower, final state shower and hadronization from Pythia where events in HEPMC format are produced. We have determined a full set of TMD parton densities and developed an initial state TMD parton shower, including all flavors following the TMD distribution. As an example of application we have calculated the azimuthal de-correlation of high [Formula: see text] dijets as measured at the LHC and found very good agreement with the measurement when including initial state TMD parton showers together with conventional final state parton showers and hadronization.

Advances in rechargeable lithium molybdenum disulfide batteries

NASA Technical Reports Server (NTRS)

Brandt, K.; Stiles, J. A. R.

1985-01-01

The lithium molybdenum disulfide system as demonstrated in a C size cell, offers performance characteristics for applications where light weight and low volume are important. A gravimetric energy density of 90 watt hours per kilogram can be achieved in a C size cell package. The combination of charge retention capabilities, high energy density and a state of charge indicator in a rechargeable cell provides power package for a wide range of devices. The system overcomes the memory effect in Nicads where the full capacity of the battery cannot be utilized unless it was utilized on previous cycles. The development of cells with an advanced electrolyte formulation led to an improved rate capability especially at low temperatures and to a significantly improved life cycle.

Sodium content in packaged foods by census division in the United States, 2009.

PubMed

Lee, Alexandra K; Schieb, Linda J; Yuan, Keming; Maalouf, Joyce; Gillespie, Cathleen; Cogswell, Mary E

2015-04-02

Excess sodium intake correlates positively with high blood pressure. Blood pressure varies by region, but whether sodium content of foods sold varies across regions is unknown. We combined nutrition and sales data from 2009 to assess the regional variation of sodium in packaged food products sold in 3 of the 9 US census divisions. Although sodium density and concentration differed little by region, fewer than half of selected food products met Food and Drug Administration sodium-per-serving conditions for labeling as "healthy." Regional differences in hypertension were not reflected in differences in the sodium content of packaged foods from grocery stores.

Proceedings of the Goddard Space Flight Center Workshop on Robotics for Commercial Microelectronic Processes in Space

NASA Technical Reports Server (NTRS)

1987-01-01

Potential applications of robots for cost effective commercial microelectronic processes in space were studied and the associated robotic requirements were defined. Potential space application areas include advanced materials processing, bulk crystal growth, and epitaxial thin film growth and related processes. All possible automation of these processes was considered, along with energy and environmental requirements. Aspects of robot capabilities considered include system intelligence, ROM requirements, kinematic and dynamic specifications, sensor design and configuration, flexibility and maintainability. Support elements discussed included facilities, logistics, ground support, launch and recovery, and management systems.

Hydrogen ion microlithography

DOEpatents

Tsuo, Y.S.; Deb, S.K.

1990-10-02

Disclosed is a hydrogen ion microlithography process for use in microelectronic fabrication and semiconductor device processing. The process comprises the steps of providing a single layer of either an amorphous silicon or hydrogenated amorphous silicon material. A pattern is recorded in a selected layer of amorphous silicon or hydrogenated amorphous silicon materials by preferentially implanting hydrogen ions therein so as to permit the selected layer to serve as a mask-resist wafer suitable for subsequent development and device fabrication. The layer is developed to provide a surface pattern therein adaptable for subsequent use in microelectronic fabrication and semiconductor device processing. 6 figs.

Microelectronic components and metallic oxide studies and applications

NASA Technical Reports Server (NTRS)

Williams, L., Jr.

1976-01-01

The project involved work in two basic areas: (1) Evaluation of commercial screen printable thick film conductors, resistors, thermistors and dielectrics as well as alumina substrates used in hybird microelectronics industries. Results of tests made on materials produced by seven companies are presented. (2) Experimental studies on metallic oxides of copper and vanadium, in an effort to determine their electrochemical properties in crystalline, powder mixtures and as screen printable thick films constituted the second phase of the research effort. Oxide investigations were aimed at finding possible applications of these materials as switching devices memory elements and sensors.

Short communication: Effect of active food packaging materials on fluid milk quality and shelf life.

PubMed

Wong, Dana E; Goddard, Julie M

2014-01-01

Active packaging, in which active agents are embedded into or on the surface of food packaging materials, can enhance the nutritive value, economics, and stability of food, as well as enable in-package processing. In one embodiment of active food packaging, lactase was covalently immobilized onto packaging films for in-package lactose hydrolysis. In prior work, lactase was covalently bound to low-density polyethylene using polyethyleneimine and glutaraldehyde cross-linkers to form the packaging film. Because of the potential contaminants of proteases, lipases, and spoilage organisms in typical enzyme preparations, the goal of the current work was to determine the effect of immobilized-lactase active packaging technology on unanticipated side effects, such as shortened shelf-life and reduced product quality. Results suggested no evidence of lipase or protease activity on the active packaging films, indicating that such active packaging films could enable in-package lactose hydrolysis without adversely affecting product quality in terms of dairy protein or lipid stability. Storage stability studies indicated that lactase did not migrate from the film over a 49-d period, and that dry storage resulted in 13.41% retained activity, whereas wet storage conditions enabled retention of 62.52% activity. Results of a standard plate count indicated that the film modification reagents introduced minor microbial contamination; however, the microbial population remained under the 20,000 cfu/mL limit through the manufacturer's suggested 14-d storage period for all film samples. This suggests that commercially produced immobilized lactase active packaging should use purified cross-linkers and enzymes. Characterization of unanticipated effects of active packaging on food quality reported here is important in demonstrating the commercial potential of such technologies. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Langmuir Probe Measurements in an Inductively Coupled Ar/CF4 Plasmas

NASA Technical Reports Server (NTRS)

Rao, M. V. V. S.; Meyyappan, M.; Sharma, S. P.; Arnold, James O. (Technical Monitor)

2000-01-01

Technological advancement in the microelectronics industry requires an understanding of the physical and chemical processes occurring in plasmas of fluorocarbon gases, such as carbon tetrafluoride (CF4) which is commonly used as an etchant, and their mixtures to optimize various operating parameters. In this paper we report data on electron number density (ne), electron temperature'(Te), electron energy distribution function (EEDF), mean electron energy, ion number density (ni), and plasma potential (Vp) measured by using Langmuir probe in an inductively coupled 13.56 MHz radio frequency plasmas generated in 50%Ar:50%CF4 mixture in the GEC cell. The probe data were recorded at various radial positions providing radial profiles of these plasma parameters at 10-50 mTorr pressures and 200 W and 300 W of RF power. Present measurements indicate that the electron and ion number densities increase with increase in pressure and power. Whereas the plasma potential and electron temperature decrease with increase in pressure, and they weakly depend on RF power. The radial profiles exhibit that the electron and ion number densities and the plasma potential peak at the center of the plasma with an exponential fall away from it, while the electron temperature has a minimum at the center and it increases steadily towards the electrode edge. The EEDFs have a characteristic drop near the low energy end at all pressures and pressures and their shapes represent non-Maxwellian plasma and exhibit more like Druyvesteyn energy distribution.v

DOE Office of Scientific and Technical Information (OSTI.GOV)

NREL developed a modeling and experimental strategy to characterize thermal performance of materials. The technique provides critical data on thermal properties with relevance for electronics packaging applications. Thermal contact resistance and bulk thermal conductivity were characterized for new high-performance materials such as thermoplastics, boron-nitride nanosheets, copper nanowires, and atomically bonded layers. The technique is an important tool for developing designs and materials that enable power electronics packaging with small footprint, high power density, and low cost for numerous applications.

GaN Nanowire Devices: Fabrication and Characterization

NASA Astrophysics Data System (ADS)

Scott, Reum

The development of microelectronics in the last 25 years has been characterized by an exponential increase of the bit density in integrated circuits (ICs) with time. Scaling solid-state devices improves cost, performance, and power; as such, it is of particular interest for companies, who gain a market advantage with the latest technology. As a result, the microelectronics industry has driven transistor feature size scaling from 10 μm to ~30 nm during the past 40 years. This trend has persisted for 40 years due to optimization, new processing techniques, device structures, and materials. But when noting processor speeds from the 1970's to 2009 and then again in 2010, the implication would be that the trend has ceased. To address the challenge of shrinking the integrated circuit (IC), current research is centered on identifying new materials and devices that can supplement and/or potentially supplant it. Bottom-up methods tailor nanoscale building blocks---atoms, molecules, quantum dots, and nanowires (NWs)---to be used to overcome these limitations. The Group IIIA nitrides (InN, AlN, and GaN) possess appealing properties such as a direct band gap spanning the whole solar spectrum, high saturation velocity, and high breakdown electric field. As a result nanostructures and nanodevices made from GaN and related nitrides are suitable candidates for efficient nanoscale UV/ visible light emitters, detectors, and gas sensors. To produce devices with such small structures new fabrication methods must be implemented. Devices composed of GaN nanowires were fabricated using photolithography and electron beam lithography. The IV characteristics of these devices were noted under different illuminations and the current tripled from 4.8*10-7 A to 1.59*10 -6 A under UV light which persisted for at least 5hrs.

Silicon Integrated Optics: Fabrication and Characterization

NASA Astrophysics Data System (ADS)

Shearn, Michael Joseph, II

For decades, the microelectronics industry has sought integration and miniaturization as canonized in Moore's Law, and has continued doubling transistor density about every two years. However, further miniaturization of circuit elements is creating a bandwidth problem as chip interconnect wires shrink as well. A potential solution is the creation of an on-chip optical network with low delays that would be impossible to achieve using metal buses. However, this technology requires integrating optics with silicon microelectronics. The lack of efficient silicon optical sources has stymied efforts of an all-Si optical platform. Instead, the integration of efficient emitter materials, such as III-V semiconductors, with Si photonic structures is a low-cost, CMOS-compatible alternative platform. This thesis focuses on making and measuring on-chip photonic structures suitable for on-chip optical networking. The first part of the thesis assesses processing techniques of silicon and other semiconductor materials. Plasmas for etching and surface modification are described and used to make bonded, hybrid Si/III-V structures. Additionally, a novel masking method using gallium implantation into silicon for pattern definition is characterized. The second part of the thesis focuses on demonstrations of fabricated optical structures. A dense array of silicon devices is measured, consisting of fully-etched grating couplers, low-loss waveguides and ring resonators. Finally, recent progress in the Si/III-V hybrid system is discussed. Supermode control of devices is described, which uses changing Si waveguide width to control modal overlap with the gain material. Hybrid Si/III-V, Fabry-Perot evanescent lasers are demonstrated, utilizing a CMOS-compatible process suitable for integration on in electronics platforms. Future prospects and ultimate limits of Si devices and the hybrid Si/III-V system are also considered.

Food losses, shelf life extension and environmental impact of a packaged cheesecake: A life cycle assessment.

PubMed

Gutierrez, Michele Mario; Meleddu, Marta; Piga, Antonio

2017-01-01

Packaging is associated with a high environmental impact. This is also the case in the food industry despite packaging being necessary for maintaining food quality, safety assurance and preventing food waste. The aim of the present study was to identify improvements in food packaging solutions able to minimize environmental externalities while maximizing the economic sustainability. To this end, the life cycle assessment (LCA) methodology was applied to evaluate the environmental performance of new packaging solutions. The environmental impact of packaging and food losses and the balance between the two were examined in relation to a cheesecake that is normally packaged in low density polyethylene film and has a limited shelf life due to microbial growth. A shelf life extension was sought via application of the well-established modified atmosphere packaging (MAP) technique. Samples for MAP (N 2 /CO 2 : 70/30) were placed inside multilayer gas barrier trays, which were then wrapped with a multilayer gas and water barrier film (i.e. AerPack packaging); control batches were packaged in gas barrier recycled polyethylene terephthalate (XrPet) trays and wrapped with a XrPet film. Samples were then stored at 20°C and inspected at regular intervals for chemical-physical, microbiological and sensory parameters. Results show that the new packaging solution could considerably extend the shelf life of cheesecakes, thereby reducing food waste and decreasing the overall environmental impact. Moreover, the new packaging allows one to minimize transport costs and to generate economies of scale in manufacturing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Packaging of MEMS/MOEMS and nanodevices: reliability, testing, and characterization aspects

NASA Astrophysics Data System (ADS)

Tekin, Tolga; Ngo, Ha-Duong; Wittler, Olaf; Bouhlal, Bouchaib; Lang, Klaus-Dieter

2011-02-01

The last decade witnessed an explosive growth in research and development efforts devoted to MEMS devices and packaging. The successfully developed MEMS devices are, for example inkjet, pressure sensors, silicon microphones, accelerometers, gyroscopes, MOEMS, micro fuel cells and emerging MEMS. For the next decade, MEMS/MOEMS and nanodevice based products will penetrate into IT, telecommunications, automotive, defense, life sciences, medical and implantable applications. Forecasts say the MEMS market to be $14 billion by 2012. The packaging cost of MEMS/MOEMS products in general is about 70 percent. Unlike today's electronics IC packaging, their packaging are custom-built and difficult due to the moving structural elements. In order for the moving elements of a MEMS device to move effectively in a well-controlled atmosphere, hermetic sealing of the MEMS device in a cap is necessary. For some MEMS devices, such as resonators and gyroscopes, vacuum packaging is required. Usually, the cap is processed at the wafer level, and thus MEMS packaging is truly a wafer level packaging. In terms of MEMS/MOEMS and nanodevice packaging, there are still many critical issues need to be addressed due to the increasing integration density supported by 3D heterogeneous integration of multi-physic components/layers consisting of photonics, electronics, rf, plasmonics, and wireless. The infrastructure of MEMS/MOEMS and nanodevices and their packaging is not well established yet. Generic packaging platform technologies are not available. Some of critical issues have been studied intensively in the last years. In this paper we will discuss about processes, reliability, testing and characterization of MEMS/MOEMS and nanodevice packaging.

Effect of ionizing radiation on physicochemical and mechanical properties of commercial multilayer coextruded flexible plastics packaging materials

NASA Astrophysics Data System (ADS)

Goulas, Antonios E.; Riganakos, Kyriakos A.; Kontominas, Michael G.

2003-12-01

The effect of gamma radiation (doses: 5, 10 and 30 kGy) on mechanical properties, gas and water vapour permeability and overall migration values into distilled water, 3% aqueous acetic acid and iso-octane was studied for a series of commercial multilayer flexible packaging materials based on coextruded polypropylene (PP), ethylene vinyl alcohol (EVOH), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), polyamide (PA) and Ionomer. The results showed that radiation doses of 5 and 10 kGy induced no statistically significant differences ( p>0.05) in all polymer properties examined. A dose of 30 kGy induced differences ( p<0.05) in the mechanical properties of PA/LDPE, LDPE/EVOH/LDPE and LDPE/PA/Ionomer films. In addition, the same dose induced differences ( p<0.05) in the overall migration from Ionomer/EVOH/LDPE and LDPE/PA/Ionomer films into 3% acetic acid and iso-octane and in the overall migration from PP/EVOH/LDPE-LLDPE into iso-octane. Differences recorded, are discussed in relation to food irradiation applications of respective packaging materials.

Radiolysis products and sensory properties of electron-beam-irradiated high-barrier food-packaging films containing a buried layer of recycled low-density polyethylene.

PubMed

Chytiri, S D; Badeka, A V; Riganakos, K A; Kontominas, M G

2010-04-01

The aim was to study the effect of electron-beam irradiation on the production of radiolysis products and sensory changes in experimental high-barrier packaging films composed of polyamide (PA), ethylene-vinyl alcohol (EVOH) and low-density polyethylene (LDPE). Films contained a middle buried layer of recycled LDPE, while films containing 100% virgin LDPE as the middle buried layer were taken as controls. Irradiation doses ranged between zero and 60 kGy. Generally, a large number of radiolysis products were produced during electron-beam irradiation, even at the lower absorbed doses of 5 and 10 kGy (approved doses for food 'cold pasteurization'). The quantity of radiolysis products increased with irradiation dose. There were no significant differences in radiolysis products identified between samples containing a recycled layer of LDPE and those containing virgin LDPE (all absorbed doses), indicating the 'functional barrier' properties of external virgin polymer layers. Sensory properties (mainly taste) of potable water were affected after contact with irradiated as low as 5 kGy packaging films. This effect increased with increasing irradiation dose.

Thermal Characterization for a Modular 3-D Multichip Module

NASA Technical Reports Server (NTRS)

Fan, Mark S.; Plante, Jeannette; Shaw, Harry

2000-01-01

NASA Goddard Space Flight Center has designed a high-density modular 3-D multichip module (MCM) for future spaceflight use. This MCM features a complete modular structure, i.e., each stack can be removed from the package without damaging the structure. The interconnection to the PCB is through the Column Grid Array (CGA) technology. Because of its high-density nature, large power dissipation from multiple layers of circuitry is anticipated and CVD diamond films are used in the assembly for heat conduction enhancement. Since each stacked layer dissipates certain amount of heat, designing effective heat conduction paths through each stack and balancing the heat dissipation within each stack for optimal thermal performance become a challenging task. To effectively remove the dissipated heat from the package, extensive thermal analysis has been performed with finite element methods. Through these analyses, we are able to improve the thermal design and increase the total wattage of the package for maximum electrical performance. This paper provides details on the design-oriented thermal analysis and performance enhancement. It also addresses issues relating to contact thermal resistance between the diamond film and the metallic heat conduction paths.

Net costs of health worker rural incentive packages: an example from the Lao People's Democratic Republic.

PubMed

Keuffel, Eric; Jaskiewicz, Wanda; Paphassarang, Chanthakhath; Tulenko, Kate

2013-11-01

Many developing countries are examining whether to institute incentive packages that increase the share of health workers who opt to locate in rural settings; however, uncertainty exists with respect to the expected net cost (or benefit) from these packages. We utilize the findings from the discrete choice experiment surveys applied to students training to be health professionals and costing analyses in Lao People's Democratic Republic to model the anticipated effect of incentive packages on new worker location decisions and direct costs. Incorporating evidence on health worker density and health outcomes, we then estimate the expected 5-year net cost (or benefit) of each incentive packages for 3 health worker cadres--physicians, nurses/midwives, and medical assistants. Under base case assumptions, the optimal incentive package for each cadre produced a 5-year net benefit (maximum net benefit for physicians: US$ 44,000; nurses/midwives: US$ 5.6 million; medical assistants: US$ 485,000). After accounting for health effects, the expected net cost of select incentive packages would be substantially less than the original estimate of direct costs. In the case of Lao People's Democratic Republic, incentive packages that do not invest in capital-intensive components generally should produce larger net benefits. Combining discrete choice experiment surveys, costing surveys and cost-benefit analysis methods may be replicated by other developing countries to calculate whether health worker incentive packages are viable policy options.

[Effect of grain-bean package, grain-bean package dietary fiber and single whole grain dietary fiber on dyslipidemia rats].

PubMed

Liu, Yang; Zhai, Chengkai; Sun, Guiju; Zhang, Hong; Jiang, Mingxia; Zhang, Haifeng; Guo, Junling; Lan, Xi

2014-05-01

To observe and compare the effects of grain-bean package, dietary fiber (DF) extracted from grain-bean package, and DF from grain corn on the blood lipids and fatty acid synthase (FAS) activity in high-fat, high-cholesterol feeding induced dyslipidemia rats, and observe its effects on regulation of sterol regulatory element protein-1c (SREBP-1c) mRNA expression in rat liver. Consolidation 50 SD rats of clean grade feeding adaptation for one week, randomly assigned into normal control group, hyperlipidemia model group, grain-bean package group, grain-bean package DF group and grain corn group. Feed with corresponding diets for 8 weeks, and measure the total cholesterol (TC), triglyceridaemia (TG), high density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG), FAS, SREBP-1c mRNA of all groups. Compared with control group, TC, TG, FBG levels of hyperlipidemia model group were significantly increased (P < 0.05). Compared with model group, TC, TG, FBG levels of grain-bean package group, grain-bean package DF group were significantly decreased, HDL-C levels significantly increased, and activity of FAS, regulation of SREBP-1c were significantly decreased (P < 0.05). The Grain-bean package dietary fiber can improve blood lipids levels of dyslipidemia rats, and decrease FAS activity and SREBP-1c mRNA expression.

Elimination of polycyclic aromatic hydrocarbons from smoked sausages by migration into polyethylene packaging.

PubMed

Semanová, Jana; Skláršová, Božena; Šimon, Peter; Šimko, Peter

2016-06-15

The objective of this work was a study of interactions between a smoked meat product and plastic packaging to find a possibility of elimination of polycyclic aromatic hydrocarbons (PAH) from smoked sausages by migration into the packaging. Smoked meat sausages were packed into o-polyamide/low density polyethylene laminated film and content of four PAH was determined at 0, 15, 30, 45, 60, 75, 90, 120, 150 and 180 min by HPLC. During this time, total PAH4 content decreased from 30.1 to 5.7 μg/kg, benzo[a]anthracene decreased from 11.5 to 2.1 μg/kg, chrysene from 9.4 to 1.9 μg/kg, benzo[b]fluoranthene from 5.3 to 0.6 μg/kg and benzo[a]pyrene from 3.9 to 1.1 μg/kg while PAH4 content in non-packed sausages remained at a constant level. So, while sausages did not meet European safety limits set for PAH4 content of 12 μg/kg and 2 μg/kg for benzo[a]pyrene before packaging, these limits were met at the end of the experiment. This decrease was brought about by migration of PAH4 from sausages into low density polyethylene packaging bulk and the measure of decrease can be predicted by a kinetic equation, making it possible to calculate PAH content equal to any time of experiment as well as the time of interaction necessary to fulfil EU legislative limits. Copyright © 2016 Elsevier Ltd. All rights reserved.

Epoxide-mediated differential packaging of Cif and other virulence factors into outer membrane vesicles.

PubMed

Ballok, Alicia E; Filkins, Laura M; Bomberger, Jennifer M; Stanton, Bruce A; O'Toole, George A

2014-10-01

Pseudomonas aeruginosa produces outer membrane vesicles (OMVs) that contain a number of secreted bacterial proteins, including phospholipases, alkaline phosphatase, and the CFTR inhibitory factor (Cif). Previously, Cif, an epoxide hydrolase, was shown to be regulated at the transcriptional level by epoxides, which serve as ligands of the repressor, CifR. Here, we tested whether epoxides have an effect on Cif levels in OMVs. We showed that growth of P. aeruginosa in the presence of specific epoxides but not a hydrolysis product increased Cif packaging into OMVs in a CifR-independent fashion. The outer membrane protein, OprF, was also increased under these conditions, but alkaline phosphatase activity was not significantly altered. Additionally, we demonstrated that OMV shape and density were affected by epoxide treatment, with two distinct vesicle fractions present when cells were treated with epibromohydrin (EBH), a model epoxide. Vesicles isolated from the two density fractions exhibited different protein profiles in Western blotting and silver staining. We have shown that a variety of clinically or host-relevant treatments, including antibiotics, also alter the proteins packaged in OMVs. Proteomic analysis of purified OMVs followed by an analysis of transposon mutant OMVs yielded mutants with altered vesicle packaging. Finally, epithelial cell cytotoxicity was reduced in the vesicles formed in the presence of EBH, suggesting that this epoxide alters the function of the OMVs. Our data support a model whereby clinically or host-relevant signals mediate differential packaging of virulence factors in OMVs, which results in functional consequences for host-pathogen interactions. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Towards tunable and multifunctional interfaces: Multicomponent amorphous alloys and bilayer stacks

NASA Astrophysics Data System (ADS)

Kast, Matthew G.

Controlling the electronic structure and requisite charge transfer at and across interfaces is a grand challenge of materials science. Despite decades of research and numerous successes in the fields microelectronics and photovoltaics much work remains to be done. In many applications, whether they be in microelectronics, photovoltaics or display technology there is a demand for multiple functions at a single interface. Historically, existent materials were either discarded as an option due to known properties or tested with some application based figure of merit in mind. Following this, the quality of the material and/or the preparation of the surface/interface to which the material would be deposited was optimized. As the microelectronics and photovoltaics industries have matured, continued progress (faster, lower power transistors and more efficient, cheaper, abundant solar cells) will require new materials (possibly not previously existent) that are fundamentally better for their application than their highly optimized existent counter parts. The manifestation of this has been seen in the microelectronics field with introduction of hafnium silicates to replace silica (which had previously been monumentally successful) as the gate dielectrics for the most advanced transistors. Continued progress in efficient, cheap, abundant photovoltaics will require similar advances. Advances will be needed in the area of new abundant absorbers that can be deposited cheaply which result in materials with high efficiencies. In addition, selective contacts capable of extracting charge from efficient absorbers with low ohmic losses and low recombination rates will be needed. Presented here are two approaches to the multifunctional interface problem, first the use of amorphous alloys that open up the accessible composition space of thin films significantly and second the use of bilayers that loosen the requirements of a single film at an interface.

Charge collection and SEU mechanisms

NASA Astrophysics Data System (ADS)

Musseau, O.

1994-01-01

In the interaction of cosmic ions with microelectronic devices a dense electron-hole plasma is created along the ion track. Carriers are separated and transported by the electric field and under the action of the concentration gradient. The subsequent collection of these carriers induces a transient current at some electrical node of the device. This "ionocurrent" (single ion induced current) acts as any electrical perturbation in the device, propagating in the circuit and inducing failures. In bistable systems (registers, memories) the stored data can be upset. In clocked devices (microprocessors) the parasitic perturbation may propagate through the device to the outputs. This type of failure only effects the information, and do not degrade the functionally of the device. The purpose of this paper is to review the mechanisms of single event upset in microelectronic devices. Experimental and theoretical results are presented, and actual questions and problems are discussed. A brief introduction recalls the creation of the dense plasma of electron-hole pairs. The basic processes for charge collection in a simple np junction (drift and diffusion) are presented. The funneling-field effect is discussed and experimental results are compared to numerical simulations and semi-empirical models. Charge collection in actual microelectronic structures is then presented. Due to the parasitic elements, coupling effects are observed. Geometrical effects, in densely packed structures, results in multiple errors. Electronic couplings are due to the carriers in excess, acting as minority carriers, that trigger parasitic bipolar transistors. Single event upset of memory cells is discussed, based on numerical and experimental data. The main parameters for device characterization are presented. From the physical interpretation of charge collection mechanisms, the intrinsic sensitivity of various microelectronic technologies is determined and compared to experimental data. Scaling laws and future trends are finally discussed.

Accelerator mass spectrometry analysis of aroma compound absorption in plastic packaging materials

NASA Astrophysics Data System (ADS)

Stenström, Kristina; Erlandsson, Bengt; Hellborg, Ragnar; Wiebert, Anders; Skog, Göran; Nielsen, Tim

1994-05-01

Absorption of aroma compounds in plastic packaging materials may affect the taste of the packaged food and it may also change the quality of the packaging material. A method to determine the aroma compound absorption in polymers by accelerator mass spectrometry (AMS) is being developed at the Lund Pelletron AMS facility. The high sensitivity of the AMS method makes it possible to study these phenomena under realistic conditions. As a first test low density polyethylene exposed to 14C-doped ethyl acetate is examined. After converting the polymer samples with the absorbed aroma compounds to graphite, the {14C }/{13C } ratio of the samples is measured by the AMS system and the degree of aroma compound absorption is established. The results are compared with those obtained by supercritical fluid extraction coupled to gas chromatography (SFE-GC).

Control of lipid oxidation by nonmigratory active packaging films prepared by photoinitiated graft polymerization.

PubMed

Tian, Fang; Decker, Eric A; Goddard, Julie M

2012-08-08

Transition metal-promoted oxidation impacts the quality, shelf life, and nutrition of many packaged foods. Metal-chelating active packaging therefore offers a means to protect foods against oxidation. Herein, we report the development and characterization of nonmigratory metal-chelating active packaging. To prepare the films, carboxylic acids were grafted onto the surfaces of polypropylene films by photoinitiated graft polymerization of acrylic acid. Attenuated total reflectance/Fourier transform infrared spectroscopy, contact angle, scanning electron microscopy, and iron-chelating assay were used to characterize film properties. Graft polymerization yielded a carboxylic acid density of 68.67 ± 9.99 nmol per cm(2) film, with ferrous iron-chelating activity of 71.07 ± 12.95 nmol per cm(2). The functionalized films extended the lag phase of lipid oxidation in a soybean oil-in-water emulsion system from 2 to 9 days. The application of such nonmigratory active packaging films represents a promising approach to reduce additive use while maintaining food quality.

Packaging-induced failure of semiconductor lasers and optical telecommunications components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharps, J.A.

1996-12-31

Telecommunications equipment for field deployment generally have specified lifetimes of > 100,000 hr. To achieve this high reliability, it is common practice to package sensitive components in hermetic, inert gas environments. The intent is to protect components from particulate and organic contamination, oxidation, and moisture. However, for high power density 980 nm diode lasers used in optical amplifiers, the authors found that hermetic, inert gas packaging induced a failure mode not observed in similar, unpackaged lasers. They refer to this failure mode as packaging-induced failure, or PIF. PIF is caused by nanomole amounts of organic contamination which interact with highmore » intensity 980 nm light to form solid deposits over the emitting regions of the lasers. These deposits absorb 980 nm light, causing heating of the laser, narrowing of the band gap, and eventual thermal runaway. The authors have found PIF is averted by packaging with free O{sub 2} and/or a getter material that sequesters organics.« less

Numerical Simulation of Doped Targets for ICF

NASA Astrophysics Data System (ADS)

Phillips, Lee; Gardner, John H.; Bodner, Stephen E.; Colombant, Denis; Klapisch, Marcel; Bar-Shalom, Avraham

1997-11-01

The ablative Rayleigh-Taylor (RT) instability can be reduced by preheating the ablator, thereby reducing the peak density and increasing the mass ablation velocity. The ablator can be preheated with radiation from higher Z dopants.(Gardner, J.H., Bodner, S.E., Dahlburg, J.P., Phys. Fluids 3), 1070 (1991) Dopants also reduce the density gradient at the ablator, which provides a second mechanism to reduce the RT growth rate. We have recently developed a more sophisticated and detailed radiation package that uses opacities generated by an STA code, with non-LTE radiation transport based on the Busquet method. This radiation package has been incorporated into NRL's FAST2D radiation hydrodynamics code, which has been used to evaluate and optimize the use of various dopants that can provide interesting levels of preheat for an ICF target.

A High-Density, High-Efficiency, Isolated On-Board Vehicle Battery Charger Utilizing Silicon Carbide Power Devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitaker, B; Barkley, A; Cole, Z

2014-05-01

This paper presents an isolated on-board vehicular battery charger that utilizes silicon carbide (SiC) power devices to achieve high density and high efficiency for application in electric vehicles (EVs) and plug-in hybrid EVs (PHEVs). The proposed level 2 charger has a two-stage architecture where the first stage is a bridgeless boost ac-dc converter and the second stage is a phase-shifted full-bridge isolated dc-dc converter. The operation of both topologies is presented and the specific advantages gained through the use of SiC power devices are discussed. The design of power stage components, the packaging of the multichip power module, and themore » system-level packaging is presented with a primary focus on system density and a secondary focus on system efficiency. In this work, a hardware prototype is developed and a peak system efficiency of 95% is measured while operating both power stages with a switching frequency of 200 kHz. A maximum output power of 6.1 kW results in a volumetric power density of 5.0 kW/L and a gravimetric power density of 3.8 kW/kg when considering the volume and mass of the system including a case.« less

Scalable Sub-micron Patterning of Organic Materials Toward High Density Soft Electronics

PubMed Central

Kim, Jaekyun; Kim, Myung-Gil; Kim, Jaehyun; Jo, Sangho; Kang, Jingu; Jo, Jeong-Wan; Lee, Woobin; Hwang, Chahwan; Moon, Juhyuk; Yang, Lin; Kim, Yun-Hi; Noh, Yong-Young; Yun Jaung, Jae; Kim, Yong-Hoon; Kyu Park, Sung

2015-01-01

The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. In this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. The successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics. PMID:26411932

SkinChip, a new tool for investigating the skin surface in vivo.

PubMed

Lévêque, Jean Luc; Querleux, Bernard

2003-11-01

Non-invasive methods used for characterizing skin micro-relief and skin surface hydration were developed in the 1980s. Although they allowed some progress in the knowledge of skin properties, they are not completely satisfactory in many aspects. Today, new technologies are emerging that may address such issues. We adapted the technology produced by the ST Microelectronics Company for sensing fingerprint for the measurement of skin surface properties. Accordingly, we developed acquisition software for obtaining routinely the distribution of skin surface capacitance along different body sites. Image analysis softwares were also processed for collecting both the main orientations of the micro-relief lines and their density. The average value of skin capacitance is also obtained. The images allow a highly precise observation of the skin topography that can be easily quantified in terms of line density and line orientation. The mean gray levels of the images appear much closely correlated to the Corneometer values. This new device appears to be a very convenient way for characterizing the properties of the skin surface. With regard to hydration, it usefully provides both the average value and the hydration chart of the investigated skin zones.

Interactions of atomic hydrogen with amorphous SiO2

NASA Astrophysics Data System (ADS)

Yue, Yunliang; Wang, Jianwei; Zhang, Yuqi; Song, Yu; Zuo, Xu

2018-03-01

Dozens of models are investigated by the first-principles calculations to simulate the interactions of an atomic hydrogen with a defect-free random network of amorphous SiO2 (a-SiO2) and oxygen vacancies. A wide variety of stable configurations are discovered due to the disorder of a-SiO2, and their structures, charges, magnetic moments, spin densities, and density of states are calculated. The atomic hydrogen interacts with the defect-free a-SiO2 in positively or negatively charged state, and produces the structures absent in crystalline SiO2. It passivates the neutral oxygen vacancies and generates two neutral hydrogenated E‧ centers with different Si dangling bond projections. Electron spin resonance parameters, including Fermi contacts, and g-tensors, are calculated for these centers. The atomic hydrogen interacts with the positive oxygen vacancies in dimer configuration, and generate four different positive hydrogenated defects, two of which are puckered like the Eγ‧ centers. This research helps to understand the interactions between an atomic hydrogen, and defect-free a-SiO2 and oxygen vacancies, which may generate the hydrogen-complexed defects that play a key role in the degeneration of silicon/silica-based microelectronic devices.

Scalable sub-micron patterning of organic materials toward high density soft electronics

DOE PAGES

Kim, Jaekyun; Kim, Myung -Gil; Kim, Jaehyun; ...

2015-09-28

The success of silicon based high density integrated circuits ignited explosive expansion of microelectronics. Although the inorganic semiconductors have shown superior carrier mobilities for conventional high speed switching devices, the emergence of unconventional applications, such as flexible electronics, highly sensitive photosensors, large area sensor array, and tailored optoelectronics, brought intensive research on next generation electronic materials. The rationally designed multifunctional soft electronic materials, organic and carbon-based semiconductors, are demonstrated with low-cost solution process, exceptional mechanical stability, and on-demand optoelectronic properties. Unfortunately, the industrial implementation of the soft electronic materials has been hindered due to lack of scalable fine-patterning methods. Inmore » this report, we demonstrated facile general route for high throughput sub-micron patterning of soft materials, using spatially selective deep-ultraviolet irradiation. For organic and carbon-based materials, the highly energetic photons (e.g. deep-ultraviolet rays) enable direct photo-conversion from conducting/semiconducting to insulating state through molecular dissociation and disordering with spatial resolution down to a sub-μm-scale. As a result, the successful demonstration of organic semiconductor circuitry promise our result proliferate industrial adoption of soft materials for next generation electronics.« less

Functionalization of poly(methyl methacrylate) (PMMA) as a substrate for DNA microarrays

PubMed Central

Fixe, F.; Dufva, M.; Telleman, P.; Christensen, C. B. V.

2004-01-01

A chemical procedure was developed to functionalize poly(methyl methacrylate) (PMMA) substrates. PMMA is reacted with hexamethylene diamine to yield an aminated surface for immobilizing DNA in microarrays. The density of primary NH2 groups was 0.29 nmol/cm2. The availability of these primary amines was confirmed by the immobilization of DNA probes and hybridization with a complementary DNA strand. The hybridization signal and the hybridization efficiency of the chemically aminated PMMA slides were comparable to the hybridization signal and the hybridization efficiency obtained from differently chemically modified PMMA slides, silanized glass, commercial silylated glass and commercial plastic Euray™ slides. Immobilized and hybridized densities of 10 and 0.75 pmol/cm2, respectively, were observed for microarrays on chemically aminated PMMA. The immobilized probes were heat stable since the hybridization performance of microarrays subjected to 20 PCR heat cycles was only reduced by 4%. In conclusion, this new strategy to modify PMMA provides a robust procedure to immobilize DNA, which is a very useful substrate for fabricating single use diagnostics devices with integrated functions, like sample preparation, treatment and detection using microfabrication and microelectronic techniques. PMID:14718554

Enhanced discharge energy density of rGO/PVDF nanocomposites: The role of the heterointerface

NASA Astrophysics Data System (ADS)

Zhang, Ye; Wang, Yaqiong; Qi, Shaojun; Dunn, Steve; Dong, Hanshan; Button, Tim

2018-05-01

Recent reports of conductive-filler/polymer composites with large dielectric permittivity (K) make them potential candidates for flexible capacitors. Hence, an interesting question is how these high K composites behave under a strong electric field strength. In this letter, we use in-situ-reduced graphite oxide (rGO)/poly(vinylidene fluoride) (PVDF) nanocomposites as an example to study the energy storage behaviour of high K materials. We show the dielectric behaviour contrasts between weak and strong fields. High K materials inevitably become more lossy with increasing field strength. Simultaneously, we reveal that the in-situ reduction temperature can affect the energy storage performance. Improved energy storage performance is achieved for a nanocomposite reduced at a moderate temperature. When reduced at 160 °C, a device with an rGO volume fraction of 1.5 vol. % displayed a discharge energy density of 0.67 J/cm3 at 50 MV/m. This was 2.9 times greater than pure PVDF. We develop a model to explain this behaviour that proposes a reduced electrical contrast of the rGO/PVDF heterointerface minimising the recombination of localized charge carriers. Our results indicate, simultaneously, the potential and limitation of high K nanocomposites and shed light on the optimisation of the design and fabrication of high discharge energy density flexible capacitors for microelectronic devices.

All-solid-state flexible microsupercapacitors based on reduced graphene oxide/multi-walled carbon nanotube composite electrodes

NASA Astrophysics Data System (ADS)

Mao, Xiling; Xu, Jianhua; He, Xin; Yang, Wenyao; Yang, Yajie; Xu, Lu; Zhao, Yuetao; Zhou, Yujiu

2018-03-01

All-solid-state flexible microsupercapacitors have been intensely investigated in order to meet the rapidly growing demands for portable microelectronic devices. Herein, we demonstrate a facile, readily scalable and cost-effective laser induction process for preparing reduced graphene oxide/multi-walled carbon nanotube composite, which can be used as the interdigital electrodes in microsupercapacitors. The obtained composite exhibits high volumetric capacitance about 49.35 F cm-3, which is nearly 5 times higher than that of the pristine reduced graphene oxide film in aqueous 1.0 M H2SO4 solution (measured at a current density of 5 A cm-3 in a three-electrode testing). Additionally, an all-solid-state flexible microsupercapacitor employing these composite electrodes with PVA/H3PO4 gel electrolyte delivers high volumetric energy density of 6.47 mWh cm-3 at 10 mW cm-3 under the current density of 20 mA cm-3 as well as achieve excellent cycling stability retaining 88.6% of its initial value and outstanding coulombic efficiency after 10,000 cycles. Furthermore, the microsupercapacitors array connected in series/parallel can be easily adjusted to achieve the demands in practical applications. Therefore, this work brings a promising new candidate of prepare technologies for all-solid-state flexible microsupercapacitors as miniaturized power sources used in the portable and wearable electronics.

Eye vision system using programmable micro-optics and micro-electronics

NASA Astrophysics Data System (ADS)

Riza, Nabeel A.; Amin, M. Junaid; Riza, Mehdi N.

2014-02-01

Proposed is a novel eye vision system that combines the use of advanced micro-optic and microelectronic technologies that includes programmable micro-optic devices, pico-projectors, Radio Frequency (RF) and optical wireless communication and control links, energy harvesting and storage devices and remote wireless energy transfer capabilities. This portable light weight system can measure eye refractive powers, optimize light conditions for the eye under test, conduct color-blindness tests, and implement eye strain relief and eye muscle exercises via time sequenced imaging. Described is the basic design of the proposed system and its first stage system experimental results for vision spherical lens refractive error correction.

European semiconductor industry: Markets, government programs

NASA Astrophysics Data System (ADS)

Scharf, A.

1983-01-01

The marketing of the semiconductor industry in Europe and especially microelectronics which is situated between the millstones of USA and Japan is discussed. The concerned enterprises and governments appear to lack the motivation for close cooperation using European resources, corresponding to the ideas of the contracts on which the common market is based. It is felt that microelectronics is promoted in individual countries under more national perspectives, and the enterprises are pursuing strictly their own interests in cooperating with predominantly American and Japanese partners. An insight into the European semiconductor scene, its markets, as well as assistance for promotion and establishment available in the individual countries is discussed.

The MOS silicon gate technology and the first microprocessors

NASA Astrophysics Data System (ADS)

Faggin, F.

2015-12-01

Today we are so used to the enormous capabilities of microelectronics that it is hard to imagine what it might have been like in the early Sixties and Seventies when much of the technology we use today was being developed. This paper will first present a brief history of microelectronics and computers, taking us to the threshold of the inventions of the MOS silicon gate technology and the microprocessor. These two creations provided the basic technology that would allow only a few years later to merge microelectronics and computers into the first commercial monolithic computer. By the late Seventies, the first monolithic computer weighting less than one gram, occupying a volume of less than one cubic centimeter, dissipating less than one Watt, and selling for less than ten dollars, could perform more information processing than the UNIVAC I, the first commercial electronic computer introduced in 1951, made with 5200 vacuum tubes, dissipating 125kW, weighting 13 metric tons, occupying a room larger than 35m2, and selling for more than one million dollars per unit. The first-person story of the SGT and the early microprocessors will be told by the Italian-born physicist who led both projects.

Novel Physical Model for DC Partial Discharge in Polymeric Insulators

NASA Astrophysics Data System (ADS)

Andersen, Allen; Dennison, J. R.

The physics of DC partial discharge (DCPD) continues to pose a challenge to researchers. We present a new physically-motivated model of DCPD in amorphous polymers based on our dual-defect model of dielectric breakdown. The dual-defect model is an extension of standard static mean field theories, such as the Crine model, that describe avalanche breakdown of charge carriers trapped on uniformly distributed defect sites. It assumes the presence of both high-energy chemical defects and low-energy thermally-recoverable physical defects. We present our measurements of breakdown and DCPD for several common polymeric materials in the context of this model. Improved understanding of DCPD and how it relates to eventual dielectric breakdown is critical to the fields of spacecraft charging, high voltage DC power distribution, high density capacitors, and microelectronics. This work was supported by a NASA Space Technology Research Fellowship.

Classifying the Basic Parameters of Ultraviolet Copper Bromide Laser

NASA Astrophysics Data System (ADS)

Gocheva-Ilieva, S. G.; Iliev, I. P.; Temelkov, K. A.; Vuchkov, N. K.; Sabotinov, N. V.

2009-10-01

The performance of deep ultraviolet copper bromide lasers is of great importance because of their applications in medicine, microbiology, high-precision processing of new materials, high-resolution laser lithography in microelectronics, high-density optical recording of information, laser-induced fluorescence in plasma and wide-gap semiconductors and more. In this paper we present a statistical study on the classification of 12 basic lasing parameters, by using different agglomerative methods of cluster analysis. The results are based on a big amount of experimental data for UV Cu+ Ne-CuBr laser with wavelengths 248.6 nm, 252.9 nm, 260.0 nm and 270.3 nm, obtained in Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences. The relevant influence of parameters on laser generation is also evaluated. The results are applicable in computer modeling and planning the experiments and further laser development with improved output characteristics.

A study of nuclear structure for 244Cm, 241Am, 238Pu, 210Po, 147Pm, 137Cs, 90Sr and 63Ni nuclei used in nuclear battery

NASA Astrophysics Data System (ADS)

Artun, Ozan

2017-07-01

In this paper, we intend to extend the nuclear data of 244Cm, 241Am, 238Pu, 210Po, 147Pm, 137Cs, 90Sr and 63Ni nuclei used in nuclear battery technology, because, these nuclei are quite important for space investigations in radioisotope thermoelectric generator (RTG) and for microelectronic technologies in betavoltaic batteries. Therefore, the nuclear structure properties of nuclei such as separation energies, neutron skin thicknesses, proton, charge and neutron density distributions as a function of radius, the root mean square (rms) proton, charge and neutron radii, binding energies per particle, have been investigated by Hartree-Fock with eight different Skyrme forces. The obtained results have been compared with the experimental data in literature and relativistic mean field theory (RMFT) results.

Electrostatic capacitance and Faraday cage behavior of carbon nanotube forests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ya'akobovitz, A.; Department of Mechanical Engineering, Faculty of Engineering Sciences, Ben-Gurion University, Beer-Sheva; Bedewy, M.

2015-02-02

Understanding of the electrostatic properties of carbon nanotube (CNT) forests is essential to enable their integration in microelectronic and micromechanical devices. In this study, we sought to understand how the hierarchical geometry and morphology of CNT forests determines their capacitance. First, we find that at small gaps, solid micropillars have greater capacitance, yet at larger gaps the capacitance of the CNT forests is greater. The surface area of the CNT forest accessible to the electrostatic field was extracted by analysis of the measured capacitance, and, by relating the capacitance to the average density of CNTs in the forest, we findmore » that the penetration depth of the electrostatic field is on the order of several microns. Therefore, CNT forests can behave as a miniature Faraday cage. The unique electrostatic properties of CNT forests could therefore enable their use as long-range proximity sensors and as shielding elements for miniature electronic devices.« less

Evaluation of high temperature dielectric films for high voltage power electronic applications

NASA Technical Reports Server (NTRS)

Suthar, J. L.; Laghari, J. R.

1992-01-01

Three high temperature films, polyimide, Teflon perfluoroalkoxy and poly-P-xylene, were evaluated for possible use in high voltage power electronic applications, such as in high energy density capacitors, cables and microelectronic circuits. The dielectric properties, including permittivity and dielectric loss, were obtained in the frequency range of 50 Hz to 100 kHz at temperatures up to 200 C. The dielectric strengths at 60 Hz were determined as a function of temperature to 250 C. Confocal laser microscopy was performed to diagnose for voids and microimperfections within the film structure. The results obtained indicate that all films evaluated are capable of maintaining their high voltage properties, with minimal degradation, at temperatures up to 200 C. However, above 200 C, they lose some of their electrical properties. These films may therefore become viable candidates for high voltage power electronic applications at high temperatures.

Single-ion adsorption and switching in carbon nanotubes

DOE PAGES

Bushmaker, Adam W.; Oklejas, Vanessa; Walker, Don; ...

2016-01-25

Single-ion detection has, for many years, been the domain of large devices such as the Geiger counter, and studies on interactions of ionized gasses with materials have been limited to large systems. To date, there have been no reports on single gaseous ion interaction with microelectronic devices, and single neutral atom detection techniques have shown only small, barely detectable responses. Here we report the observation of single gaseous ion adsorption on individual carbon nanotubes (CNTs), which, because of the severely restricted one-dimensional current path, experience discrete, quantized resistance increases of over two orders of magnitude. Only positive ions cause changes,more » by the mechanism of ion potentialinduced carrier depletion, which is supported by density functional and Landauer transport theory. Lastly, our observations reveal a new single-ion/CNT heterostructure with novel electronic properties, and demonstrate that as electronics are ultimately scaled towards the one-dimensional limit, atomic-scale effects become increasingly important.« less

Electrostatic capacitance and Faraday cage behavior of carbon nanotube forests

NASA Astrophysics Data System (ADS)

Ya'akobovitz, A.; Bedewy, M.; Hart, A. J.

2015-02-01

Understanding of the electrostatic properties of carbon nanotube (CNT) forests is essential to enable their integration in microelectronic and micromechanical devices. In this study, we sought to understand how the hierarchical geometry and morphology of CNT forests determines their capacitance. First, we find that at small gaps, solid micropillars have greater capacitance, yet at larger gaps the capacitance of the CNT forests is greater. The surface area of the CNT forest accessible to the electrostatic field was extracted by analysis of the measured capacitance, and, by relating the capacitance to the average density of CNTs in the forest, we find that the penetration depth of the electrostatic field is on the order of several microns. Therefore, CNT forests can behave as a miniature Faraday cage. The unique electrostatic properties of CNT forests could therefore enable their use as long-range proximity sensors and as shielding elements for miniature electronic devices.

Basic EMC (Electromagnetic compatibility) technology advancement for C3 (Command, control, and communications) systems. Volume 6

NASA Astrophysics Data System (ADS)

Weiner, D.; Paul, C. R.; Whalen, J.

1985-04-01

This research effort was devoted to eliminating some of the basic technological gaps in the two important areas of: (1) electromagnetic effects (EM) on microelectronic circuits and (2) EM coupling and testing. The results are presented in fourteen reports which have been organized into six volumes. The reports are briefly summarized in this volume. In addition, an experiment is described which was performed to demonstrate the feasibility of applying several of the results to a problem involving electromagnetic interference. Specifically, experimental results are provided for the randomness associated with: (1) crosstalk in cable harnesses and (2) demodulation of amplitude modulated (AM) signals in operational amplifiers. These results are combined to predict candidate probability density functions (pdf's) for the amplitude of an AM interfering signal required to turn on a light emitting diode. The candidate pdf's are shown to be statistically consistent with measured data.

Dislocation-pipe diffusion in nitride superlattices observed in direct atomic resolution.

PubMed

Garbrecht, Magnus; Saha, Bivas; Schroeder, Jeremy L; Hultman, Lars; Sands, Timothy D

2017-04-06

Device failure from diffusion short circuits in microelectronic components occurs via thermally induced migration of atoms along high-diffusivity paths: dislocations, grain boundaries, and free surfaces. Even well-annealed single-grain metallic films contain dislocation densities of about 10 14  m -2 ; hence dislocation-pipe diffusion (DPD) becomes a major contribution at working temperatures. While its theoretical concept was established already in the 1950s and its contribution is commonly measured using indirect tracer, spectroscopy, or electrical methods, no direct observation of DPD at the atomic level has been reported. We present atomically-resolved electron microscopy images of the onset and progression of diffusion along threading dislocations in sequentially annealed nitride metal/semiconductor superlattices, and show that this type of diffusion can be independent of concentration gradients in the system but governed by the reduction of strain fields in the lattice.

Thermally stable, low dielectric polyquinolines for aerospace and electronics applications

NASA Technical Reports Server (NTRS)

Hendricks, Neil H.; Marrocco, Matthew L.; Stoakley, Diane M.; St. Clair, Anne K.

1990-01-01

Four new high molecular weight, linear chain polyquinolines have been synthesized and fabricated into high quality free standing films. These polymers are characterized by moderate to high glass transition temperatures, excellent thermal and thermooxidative stability, extremely low dielectric constants and good planarizing characteristics. The polymers absorb very low quantities of moisture. As a consequence, the dielectric constant of one new polyquinoline has been shown to be quite insensitive to exposure to warm/wet conditions. Isothermal aging of one new derivative in air has been carried out at elevated temperatures (250 C to 345 C). The results demonstrate truly outstanding thermooxidative stability. Additional characterizations include molecular weight determinations, solubilities and film-forming characteristics, density measurements, and UV-Vis spectroscopy. The data acquired to date suggest that the polymers may find use as refractive films and coatings and as interlevel planarizers in microelectronics applications.

21 CFR 178.3130 - Antistatic and/or anti-fogging agents in food-packaging materials.

Code of Federal Regulations, 2010 CFR

2010-04-01

... antistatic agent at levels not to exceed 0.2 percent by weight in molded or extruded high-density polyethylene (having a density ≥0.95 g/cm3 and polypropylene containers that contact food only of the types... levels not to exceed 0.15 pct by weight in molded or extruded polyethylene containers that contact food...

Study on ternary low density polyethylene/linear low density polyethylene/thermoplastic starch blend films.

PubMed

Sabetzadeh, Maryam; Bagheri, Rouhollah; Masoomi, Mahmood

2015-03-30

In this work, low-density polyethylene/linear low-density polyethylene/thermoplastic starch (LDPE/LLDPE/TPS) films are prepared with the aim of obtaining environmentally friendly materials containing high TPS content with required packaging properties. Blending of LDPE/LLDPE (70/30 wt/wt) with 5-20 wt% of TPS and 3 wt% of PE-grafted maleic anhydride (PE-g-MA) is performed in a twin-screw extruder, followed by the blowing process. Differential scanning calorimetric results indicate starch has more pronounced effect on crystallization of LLDPE than LDPE. Scanning electron micrograph shows a fairly good dispersion of TPS in PE matrices. Fourier transfer infrared spectra confirm compatibility between polymers using PE-g-MA as the compatibilizer. Storage modulus, loss modulus and complex viscosity increase with incorporation of starch. Tensile strength and elongation-at-break decrease from 18 to 10.5 MPa and 340 to 200%, respectively when TPS increases from 5 to 20%. However, the required mechanical properties for packaging applications are attained when 15 wt% starch is added, as specified in ASTM D4635. Finally 12% increase in water uptake is achieved with inclusion of 15 wt% starch. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nondestructive determination of activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chabalier, B.

1996-08-01

Characterization and appraisal tests include the measurement of activity in raw waste and waste packages. After conditioning, variations in density, matrix composition, and geometry make evaluation of the radionuclide activity in a package destined for storage nearly impossible without measurements and with a low uncertainty. Various nondestructive measuring techniques that use ionizing radiation are employed to characterize waste packages and raw waste. Gamma spectrometry is the most widely used technique because of its simple operation and low cost. This technique is used to quantify the beta-gamma and alpha activity of gamma-emitting radionuclides as well as to check the radioactive homogeneitymore » of the waste packages. Numerous systems for directly measuring waste packages have been developed. Two types of methods may be distinguished, depending on whether results that come from the measurements are weighted by an experimentally determined corrective term or by calculation. Through the MARCO and CARACO measuring systems, a method is described that allows one to quantify the activity of the beta-gamma and alpha radionuclides contained in either a waste package or raw waste whose geometries and material compositions are more or less accurately known. This method is based on (a) measurement by gamma spectrometry of the beta-gamma and alpha activity of the gamma-emitting radionuclides contained in the waste package and (b) the application of calculated corrections; thus, the limitations imposed by reference package geometry and matrix are avoided.« less

Compact DFB laser modules with integrated isolator at 935 nm

NASA Astrophysics Data System (ADS)

Reggentin, M.; Thiem, H.; Tsianos, G.; Malach, M.; Hofmann, J.; Plocke, T.; Kneier, M.; Richter, L.

2018-02-01

New developments in industrial applications and applications under rough environmental conditions within the field of spectroscopy and quantum technology in the 935 nm wavelength regime demand new compact, stable and robust laser systems. Beside a stable laser source the integration of a compact optical isolator is necessary to reduce size and power consumption for the whole laser system. The integration of a suitable optical isolator suppresses back reflections from the following optical system efficiently. However, the miniaturization of the optics inside the package leads to high optical power density levels that make a more detailed analysis of the components and their laser damage threshold necessary. We present test results on compact stable DFB laser sources (butterfly style packages) with newly integrated optical isolators operating around 935 nm. The presented data includes performance and lifetime tests for the laser diodes as well as package components. Overall performance data of the packaged laser diodes will be shown as well.

Impact of nano-CaCO3 -LDPE packaging on quality of fresh-cut sugarcane.

PubMed

Luo, Zisheng; Wang, Yansheng; Wang, Haohui; Feng, Simin

2014-12-01

In order to evaluate the effects of nano-CaCO3 -based low density polyethylene (nano-CaCO3 -LDPE) packaging on the quality of fresh-cut sugarcane, concentrations of O2 and CO2 within the packages, overall visual quality (OVQ), total bacterial count (TBC), yeast and mould count (YMC), reducing sugar content and total phenolic content, respiration, ethylene production, and the activities of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), acid invertase (AI) and neutral invertase (NI) were examined during storage at 10 °C for 5 days. The transmission rate of O2 and CO2 of the nano-CaCO3 -LDPE material was lower than that of LDPE, which lead to the more rapid formation of gas environment with low O2 and high CO2 concentration in the package. TBC and YMC counts of fresh-cut sugarcane were significantly retarded by nano-CaCO3 -LDPE packaging. Nano-CaCO3 -LDPE packaging fresh-cut sugarcane exhibited significantly lower activities of PAL, PPO, POD AI and NI than LDPE packaging fresh-cut sugarcanes during the storage. Meanwhile, nano-CaCO3 -LDPE packaging significantly inhibited the increase of browning index and total phenolic content, while improving OVQ. Our results indicated that nano-CaCO3 -LDPE packaging together with the cold storage is a promising approach in inhibiting browning and maintaining quality of fresh-cut sugarcane. © 2014 Society of Chemical Industry.

Resistance to moist conditions of whey protein isolate and pea starch biodegradable films and low density polyethylene nondegradable films: a comparative study

NASA Astrophysics Data System (ADS)

Mehyar, G. F.; Bawab, A. Al

2015-10-01

Biodegradable packaging materials are degraded under the natural environmental conditions. Therefore using them could alleviate the problem of plastics accumulation in nature. For effective replacement of plastics, with biodegradable materials, biodegradable packages should keep their properties under the high relative humidity (RH) conditions. Therefore the objectives of the study were to develop biodegradable packaging material based on whey protein isolate (WPI) and pea starch (PS). To study their mechanical, oxygen barrier and solubility properties under different RHs compared with those of low density polyethylene (LDPE), the most used plastic in packaging. Films of WPI and PS were prepared separately and conditioned at different RH (30-90%) then their properties were studied. At low RHs (<50%), WPI films had 2-3 times lower elongation at break (E or stretchability) than PS and LDPE. Increasing RH to 90% significantly (P<0.01) increased the elongation of PS but not WPI and LDPE films. LDPE and WPI films kept significantly (P<0.01) higher tensile strength (TS) than PS films at high RH (90%). Oxygen permeability (OP) of all films was very low (<0.5 cm3 μm m-2 d-1 kPa-1) below 40% RH but increased for PS films and became significantly (P<0.01) different than that of LDPE and WPI at > 40% RH. Oxygen permeability of WPI and LDPE did not adversely affected by increasing RH to 65%. Furthermore, WPI and LDPE films had lower degree of hydration at 50% and 90% RH and total soluble matter than PS films. These results suggest that WPI could be successfully replacing LDPE in packaging of moist products.

Dynamics of bacteriophage genome ejection in vitro and in vivo

NASA Astrophysics Data System (ADS)

Panja, Debabrata; Molineux, Ian J.

2010-12-01

Bacteriophages, phages for short, are viruses of bacteria. The majority of phages contain a double-stranded DNA genome packaged in a capsid at a density of ~500 mg ml-1. This high density requires substantial compression of the normal B-form helix, leading to the conjecture that DNA in mature phage virions is under significant pressure, and that pressure is used to eject the DNA during infection. A large number of theoretical, computer simulation and in vitro experimental studies surrounding this conjecture have revealed many—though often isolated and/or contradictory—aspects of packaged DNA. This prompts us to present a unified view of the statistical physics and thermodynamics of DNA packaged in phage capsids. We argue that the DNA in a mature phage is in a (meta)stable state, wherein electrostatic self-repulsion is balanced by curvature stress due to confinement in the capsid. We show that in addition to the osmotic pressure associated with the packaged DNA and its counterions, there are four different pressures within the capsid: pressure on the DNA, hydrostatic pressure, the pressure experienced by the capsid and the pressure associated with the chemical potential of DNA ejection. Significantly, we analyze the mechanism of force transmission in the packaged DNA and demonstrate that the pressure on DNA is not important for ejection. We derive equations showing a strong hydrostatic pressure difference across the capsid shell. We propose that when a phage is triggered to eject by interaction with its receptor in vitro, the (thermodynamic) incentive of water molecules to enter the phage capsid flushes the DNA out of the capsid. In vivo, the difference between the osmotic pressures in the bacterial cell cytoplasm and the culture medium similarly results in a water flow that drags the DNA out of the capsid and into the bacterial cell.

Nanocellulose in green food packaging.

PubMed

Vilarinho, Fernanda; Sanches Silva, Ana; Vaz, M Fátima; Farinha, José Paulo

2018-06-13

The development of packaging materials with new functionalities and lower environmental impact is now an urgent need of our society. On one hand, the shelf-life extension of packaged products can be an answer to the exponential increase of worldwide demand for food. On the other hand, uncertainty of crude oil prices and reserves has imposed the necessity to find raw materials to replace oil-derived polymers. Additionally, consumers' awareness toward environmental issues increasingly pushes industries to look with renewed interest to "green" solutions. In response to these issues, numerous polymers have been exploited to develop biodegradable food packaging materials. Although the use of biopolymers has been limited due to their poor mechanical and barrier properties, these can be enhanced by adding reinforcing nanosized components to form nanocomposites. Cellulose is probably the most used and well-known renewable and sustainable raw material. The mechanical properties, reinforcing capabilities, abundance, low density, and biodegradability of nanosized cellulose make it an ideal candidate for polymer nanocomposites processing. Here we review the potential applications of cellulose based nanocomposites in food packaging materials, highlighting the several types of biopolymers with nanocellulose fillers that have been used to form bio-nanocomposite materials. The trends in nanocellulose packaging applications are also addressed.

46 CFR 160.037-3 - Materials, workmanship, construction, and performance requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... preclude variations of density which may adversely affect uniformity of its smoke emitting characteristics... the signal plus packaging in a sealed plastic waterproof bag satisfactory to the Commandant. (d...

Solid State Research, 1973:2.

DTIC Science & Technology

MERCURY COMPOUNDS, CADMIUM COMPOUNDS, TELLURIDES, NEODYMIUM COMPOUNDS, PHOSPHATES , ELECTRON TRANSITIONS, INFRARED OPTICAL MATERIALS, CRYSTAL GROWTH, MAGNESIUM OXIDES, PHOSPHORESCENT MATERIALS, SEMICONDUCTOR DIODES, MICROELECTRONICS

Raman Optical Activity Spectra from Density Functional Perturbation Theory and Density-Functional-Theory-Based Molecular Dynamics.

PubMed

Luber, Sandra

2017-03-14

We describe the calculation of Raman optical activity (ROA) tensors from density functional perturbation theory, which has been implemented into the CP2K software package. Using the mixed Gaussian and plane waves method, ROA spectra are evaluated in the double-harmonic approximation. Moreover, an approach for the calculation of ROA spectra by means of density functional theory-based molecular dynamics is derived and used to obtain an ROA spectrum via time correlation functions, which paves the way for the calculation of ROA spectra taking into account anharmonicities and dynamic effects at ambient conditions.

Stan : A Probabilistic Programming Language

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carpenter, Bob; Gelman, Andrew; Hoffman, Matthew D.

Stan is a probabilistic programming language for specifying statistical models. A Stan program imperatively defines a log probability function over parameters conditioned on specified data and constants. As of version 2.14.0, Stan provides full Bayesian inference for continuous-variable models through Markov chain Monte Carlo methods such as the No-U-Turn sampler, an adaptive form of Hamiltonian Monte Carlo sampling. Penalized maximum likelihood estimates are calculated using optimization methods such as the limited memory Broyden-Fletcher-Goldfarb-Shanno algorithm. Stan is also a platform for computing log densities and their gradients and Hessians, which can be used in alternative algorithms such as variational Bayes, expectationmore » propagation, and marginal inference using approximate integration. To this end, Stan is set up so that the densities, gradients, and Hessians, along with intermediate quantities of the algorithm such as acceptance probabilities, are easily accessible. Stan can also be called from the command line using the cmdstan package, through R using the rstan package, and through Python using the pystan package. All three interfaces support sampling and optimization-based inference with diagnostics and posterior analysis. rstan and pystan also provide access to log probabilities, gradients, Hessians, parameter transforms, and specialized plotting.« less

ExGUtils: A Python Package for Statistical Analysis With the ex-Gaussian Probability Density.

PubMed

Moret-Tatay, Carmen; Gamermann, Daniel; Navarro-Pardo, Esperanza; Fernández de Córdoba Castellá, Pedro

2018-01-01

The study of reaction times and their underlying cognitive processes is an important field in Psychology. Reaction times are often modeled through the ex-Gaussian distribution, because it provides a good fit to multiple empirical data. The complexity of this distribution makes the use of computational tools an essential element. Therefore, there is a strong need for efficient and versatile computational tools for the research in this area. In this manuscript we discuss some mathematical details of the ex-Gaussian distribution and apply the ExGUtils package, a set of functions and numerical tools, programmed for python, developed for numerical analysis of data involving the ex-Gaussian probability density. In order to validate the package, we present an extensive analysis of fits obtained with it, discuss advantages and differences between the least squares and maximum likelihood methods and quantitatively evaluate the goodness of the obtained fits (which is usually an overlooked point in most literature in the area). The analysis done allows one to identify outliers in the empirical datasets and criteriously determine if there is a need for data trimming and at which points it should be done.

ExGUtils: A Python Package for Statistical Analysis With the ex-Gaussian Probability Density

PubMed Central

Moret-Tatay, Carmen; Gamermann, Daniel; Navarro-Pardo, Esperanza; Fernández de Córdoba Castellá, Pedro

2018-01-01

The study of reaction times and their underlying cognitive processes is an important field in Psychology. Reaction times are often modeled through the ex-Gaussian distribution, because it provides a good fit to multiple empirical data. The complexity of this distribution makes the use of computational tools an essential element. Therefore, there is a strong need for efficient and versatile computational tools for the research in this area. In this manuscript we discuss some mathematical details of the ex-Gaussian distribution and apply the ExGUtils package, a set of functions and numerical tools, programmed for python, developed for numerical analysis of data involving the ex-Gaussian probability density. In order to validate the package, we present an extensive analysis of fits obtained with it, discuss advantages and differences between the least squares and maximum likelihood methods and quantitatively evaluate the goodness of the obtained fits (which is usually an overlooked point in most literature in the area). The analysis done allows one to identify outliers in the empirical datasets and criteriously determine if there is a need for data trimming and at which points it should be done. PMID:29765345

Stan : A Probabilistic Programming Language

DOE PAGES

Carpenter, Bob; Gelman, Andrew; Hoffman, Matthew D.; ...

2017-01-01

Stan is a probabilistic programming language for specifying statistical models. A Stan program imperatively defines a log probability function over parameters conditioned on specified data and constants. As of version 2.14.0, Stan provides full Bayesian inference for continuous-variable models through Markov chain Monte Carlo methods such as the No-U-Turn sampler, an adaptive form of Hamiltonian Monte Carlo sampling. Penalized maximum likelihood estimates are calculated using optimization methods such as the limited memory Broyden-Fletcher-Goldfarb-Shanno algorithm. Stan is also a platform for computing log densities and their gradients and Hessians, which can be used in alternative algorithms such as variational Bayes, expectationmore » propagation, and marginal inference using approximate integration. To this end, Stan is set up so that the densities, gradients, and Hessians, along with intermediate quantities of the algorithm such as acceptance probabilities, are easily accessible. Stan can also be called from the command line using the cmdstan package, through R using the rstan package, and through Python using the pystan package. All three interfaces support sampling and optimization-based inference with diagnostics and posterior analysis. rstan and pystan also provide access to log probabilities, gradients, Hessians, parameter transforms, and specialized plotting.« less

Computing and software

USGS Publications Warehouse

White, Gary C.; Hines, J.E.

2004-01-01

The reality is that the statistical methods used for analysis of data depend upon the availability of software. Analysis of marked animal data is no different than the rest of the statistical field. The methods used for analysis are those that are available in reliable software packages. Thus, the critical importance of having reliable, up–to–date software available to biologists is obvious. Statisticians have continued to develop more robust models, ever expanding the suite of potential analysis methodsavailable. But without software to implement these newer methods, they will languish in the abstract, and not be applied to the problems deserving them.In the Computers and Software Session, two new software packages are described, a comparison of implementation of methods for the estimation of nest survival is provided, and a more speculative paper about how the next generation of software might be structured is presented.Rotella et al. (2004) compare nest survival estimation with different software packages: SAS logistic regression, SAS non–linear mixed models, and Program MARK. Nests are assumed to be visited at various, possibly infrequent, intervals. All of the approaches described compute nest survival with the same likelihood, and require that the age of the nest is known to account for nests that eventually hatch. However, each approach offers advantages and disadvantages, explored by Rotella et al. (2004).Efford et al. (2004) present a new software package called DENSITY. The package computes population abundance and density from trapping arrays and other detection methods with a new and unique approach. DENSITY represents the first major addition to the analysis of trapping arrays in 20 years.Barker & White (2004) discuss how existing software such as Program MARK require that each new model’s likelihood must be programmed specifically for that model. They wishfully think that future software might allow the user to combine pieces of likelihood functions together to generate estimates. The idea is interesting, and maybe some bright young statistician can work out the specifics to implement the procedure.Choquet et al. (2004) describe MSURGE, a software package that implements the multistate capture–recapture models. The unique feature of MSURGE is that the design matrix is constructed with an interpreted language called GEMACO. Because MSURGE is limited to just multistate models, the special requirements of these likelihoods can be provided.The software and methods presented in these papers gives biologists and wildlife managers an expanding range of possibilities for data analysis. Although ease–of–use is generally getting better, it does not replace the need for understanding of the requirements and structure of the models being computed. The internet provides access to many free software packages as well as user–discussion groups to share knowledge and ideas. (A starting point for wildlife–related applications is (http://www.phidot.org).

Plato: A localised orbital based density functional theory code

NASA Astrophysics Data System (ADS)

Kenny, S. D.; Horsfield, A. P.

2009-12-01

The Plato package allows both orthogonal and non-orthogonal tight-binding as well as density functional theory (DFT) calculations to be performed within a single framework. The package also provides extensive tools for analysing the results of simulations as well as a number of tools for creating input files. The code is based upon the ideas first discussed in Sankey and Niklewski (1989) [1] with extensions to allow high-quality DFT calculations to be performed. DFT calculations can utilise either the local density approximation or the generalised gradient approximation. Basis sets from minimal basis through to ones containing multiple radial functions per angular momenta and polarisation functions can be used. Illustrations of how the package has been employed are given along with instructions for its utilisation. Program summaryProgram title: Plato Catalogue identifier: AEFC_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFC_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 219 974 No. of bytes in distributed program, including test data, etc.: 1 821 493 Distribution format: tar.gz Programming language: C/MPI and PERL Computer: Apple Macintosh, PC, Unix machines Operating system: Unix, Linux and Mac OS X Has the code been vectorised or parallelised?: Yes, up to 256 processors tested RAM: Up to 2 Gbytes per processor Classification: 7.3 External routines: LAPACK, BLAS and optionally ScaLAPACK, BLACS, PBLAS, FFTW Nature of problem: Density functional theory study of electronic structure and total energies of molecules, crystals and surfaces. Solution method: Localised orbital based density functional theory. Restrictions: Tight-binding and density functional theory only, no exact exchange. Unusual features: Both atom centred and uniform meshes available. Can deal with arbitrary angular momenta for orbitals, whilst still retaining Slater-Koster tables for accuracy. Running time: Test cases will run in a few minutes, large calculations may run for several days.

Mechanical integrity of a carbon nanotube/copper-based through-silicon via for 3D integrated circuits: a multi-scale modeling approach.

PubMed

Awad, Ibrahim; Ladani, Leila

2015-12-04

Carbon nanotube (CNT)/copper (Cu) composite material is proposed to replace Cu-based through-silicon vias (TSVs) in micro-electronic packages. The proposed material is believed to offer extraordinary mechanical and electrical properties and the presence of CNTs in Cu is believed to overcome issues associated with miniaturization of Cu interconnects, such as electromigration. This study introduces a multi-scale modeling of the proposed TSV in order to evaluate its mechanical integrity under mechanical and thermo-mechanical loading conditions. Molecular dynamics (MD) simulation was used to determine CNT/Cu interface adhesion properties. A cohesive zone model (CZM) was found to be most appropriate to model the interface adhesion, and CZM parameters at the nanoscale were determined using MD simulation. CZM parameters were then used in the finite element analysis in order to understand the mechanical and thermo-mechanical behavior of composite TSV at micro-scale. From the results, CNT/Cu separation does not take place prior to plastic deformation of Cu in bending, and separation does not take place when standard thermal cycling is applied. Further investigation is recommended in order to alleviate the increased plastic deformation in Cu at the CNT/Cu interface in both loading conditions.

Microelectronics Instrument Products Shock and Vibration Electro-Optics. Section B; Acceptance Data Package

NASA Technical Reports Server (NTRS)

1995-01-01

The motor/encoder (henceforth referred to as the UUT) test sequence began with a baseline functional evaluation, which demonstrated that the motor satisfied the operating torque, cogging torque, winding resistance, and mechanical requirements of SOW. In addition, the encoder electrical requirements were verified, as well as the alignment of the encoder outputs relative to the motor shaft position. There were no discrepancies observed in this portion of the test. The UUT was then exposed to a number of environments, including thermal vacuum, thermal cycling, random and sine vibration, and mechanical shock. During the thermal environments, the performance of the UUT under load was verified at specified points in the cycles, as described in ATP 20049. In addition, the UUT was bench tested between the two thermal environments. No anomalies were observed during the thermal tests. The vibration and shock tests were performed by East-West Technology Corporation, West Babylon, New York. The UUT was delivered to the lab in a sealed vibration fixture in order to maintain the cleanliness levels required by the SOW. In addition, a three ounce load was attached to the motor shaft. The attachment method of this load caused damage to the shaft and bearing during random vibration of S/N 0003 on April 28, 1995, and is described further in NCR 00168.

Ferroelectric nanoparticle-embedded sponge structure triboelectric generators

NASA Astrophysics Data System (ADS)

Park, Daehoon; Shin, Sung-Ho; Yoon, Ick-Jae; Nah, Junghyo

2018-05-01

We report high-performance triboelectric nanogenerators (TENGs) employing ferroelectric nanoparticles (NPs) embedded in a sponge structure. The ferroelectric BaTiO3 NPs inside the sponge structure play an important role in increasing surface charge density by polarized spontaneous dipoles, enabling the packaging of TENGs even with a minimal separation gap. Since the friction surfaces are encapsulated in the packaged device structure, it suffers negligible performance degradation even at a high relative humidity of 80%. The TENGs also demonstrated excellent mechanical durability due to the elasticity and flexibility of the sponge structure. Consequently, the TENGs can reliably harvest energy even under harsh conditions. The approach introduced here is a simple, effective, and reliable way to fabricate compact and packaged TENGs for potential applications in wearable energy-harvesting devices.

Ferroelectric nanoparticle-embedded sponge structure triboelectric generators.

PubMed

Park, Daehoon; Shin, Sung-Ho; Yoon, Ick-Jae; Nah, Junghyo

2018-05-04

We report high-performance triboelectric nanogenerators (TENGs) employing ferroelectric nanoparticles (NPs) embedded in a sponge structure. The ferroelectric BaTiO 3 NPs inside the sponge structure play an important role in increasing surface charge density by polarized spontaneous dipoles, enabling the packaging of TENGs even with a minimal separation gap. Since the friction surfaces are encapsulated in the packaged device structure, it suffers negligible performance degradation even at a high relative humidity of 80%. The TENGs also demonstrated excellent mechanical durability due to the elasticity and flexibility of the sponge structure. Consequently, the TENGs can reliably harvest energy even under harsh conditions. The approach introduced here is a simple, effective, and reliable way to fabricate compact and packaged TENGs for potential applications in wearable energy-harvesting devices.

Dry etching of metallization

NASA Technical Reports Server (NTRS)

Bollinger, D.

1983-01-01

The production dry etch processes are reviewed from the perspective of microelectronic fabrication applications. The major dry etch processes used in the fabrication of microelectronic devices can be divided into two categories - plasma processes in which samples are directly exposed to an electrical discharge, and ion beam processes in which samples are etched by a beam of ions extracted from a discharge. The plasma etch processes can be distinguished by the degree to which ion bombardment contributes to the etch process. This, in turn is related to capability for anisotropic etching. Reactive Ion Etching (RIE) and Ion Beam Etching are of most interest for etching of thin film metals. RIE is generally considered the best process for large volume, anisotropic aluminum etching.

Correction of absorption-edge artifacts in polychromatic X-ray tomography in a scanning electron microscope for 3D microelectronics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laloum, D., E-mail: david.laloum@cea.fr; CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9; STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles

2015-01-15

X-ray tomography is widely used in materials science. However, X-ray scanners are often based on polychromatic radiation that creates artifacts such as dark streaks. We show this artifact is not always due to beam hardening. It may appear when scanning samples with high-Z elements inside a low-Z matrix because of the high-Z element absorption edge: X-rays whose energy is above this edge are strongly absorbed, violating the exponential decay assumption for reconstruction algorithms and generating dark streaks. A method is proposed to limit the absorption edge effect and is applied on a microelectronic case to suppress dark streaks between interconnections.

Dual manifold system and method for fluid transfer

DOEpatents

Doktycz, Mitchel J [Knoxville, TN; Bryan, William Louis [Knoxville, TN; Kress, Reid [Oak Ridge, TN

2003-05-27

A dual-manifold assembly is provided for the rapid, parallel transfer of liquid reagents from a microtiter plate to a solid state microelectronic device having biological sensors integrated thereon. The assembly includes aspiration and dispense manifolds connected by a plurality of conduits. In operation, the aspiration manifold is actuated such that the aspiration manifold is seated onto an array of reagent-filled wells of the microtiter plate. The wells are pressurized to force reagent through conduits toward the dispense manifold. A pressure pulse provided by a standard ink-jet printhead ejects nanoliter-to-picoliter droplets of reagent through an array of printhead orifices and onto test sites on the surface of the microelectronic device.

Dual manifold system and method for fluid transfer

DOEpatents

Doktycz, Mitchel J.; Bryan, William Louis; Kress, Reid

2003-09-30

A dual-manifold assembly is provided for the rapid, parallel transfer of liquid reagents from a microtiter plate to a solid state microelectronic device having biological sensors integrated thereon. The assembly includes aspiration and dispense manifolds connected by a plurality of conduits. In operation, the aspiration manifold is actuated such that the aspiration manifold is seated onto an array of reagent-filled wells of the microtiter plate. The wells are pressurized to force reagent through conduits toward the dispense manifold. A pressure pulse provided by a standard ink-jet printhead ejects nanoliter-to-picoliter droplets of reagent through an array of printhead orifices and onto test sites on the surface of the microelectronic device.

MEMS reliability: The challenge and the promise

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, W.M.; Tanner, D.M.; Miller, S.L.

1998-05-01

MicroElectroMechanical Systems (MEMS) that think, sense, act and communicate will open up a broad new array of cost effective solutions only if they prove to be sufficiently reliable. A valid reliability assessment of MEMS has three prerequisites: (1) statistical significance; (2) a technique for accelerating fundamental failure mechanisms, and (3) valid physical models to allow prediction of failures during actual use. These already exist for the microelectronics portion of such integrated systems. The challenge lies in the less well understood micromachine portions and its synergistic effects with microelectronics. This paper presents a methodology addressing these prerequisites and a description ofmore » the underlying physics of reliability for micromachines.« less

Evaluation of advanced microelectronics for inclusion in MIL-STD-975

NASA Technical Reports Server (NTRS)

Scott, W. Richard

1991-01-01

The approach taken by NASA and JPL (Jet Propulsion Laboratory) in the development of a MIL-STD-975 section which contains advanced technology such as Large Scale Integration and Very Large Scale Integration (LSI/VLSI) microelectronic devices is described. The parts listed in this section are recommended as satisfactory for NASA flight applications, in the absence of alternate qualified devices, based on satisfactory results of a vendor capability audit, the availability of sufficient characterization and reliability data from the manufacturers and users and negotiated detail procurement specifications. The criteria used in the selection and evaluation of the vendors and candidate parts, the preparation of procurement specifications, and the status of this activity are discussed.

The design of radiation-hardened ICs for space - A compendium of approaches

NASA Technical Reports Server (NTRS)

Kerns, Sherra E.; Shafer, B. D; Rockett, L. R., Jr.; Pridmore, J. S.; Berndt, D. F.

1988-01-01

Several technologies, including bulk and epi CMOS, CMOS/SOI-SOS (silicon-on-insulator-silicon-on-sapphire), CML (current-mode logic), ECL (emitter-coupled logic), analog bipolar (JI, single-poly DI, and SOI) and GaAs E/D (enhancement/depletion) heterojunction MESFET, are discussed. The discussion includes the direct effects of space radiation on microelectronic materials and devices, how these effects are evidenced in circuit and device design parameter variations, the particular effects of most significance to each functional class of circuit, specific techniques for hardening high-speed circuits, design examples for integrated systems, including operational amplifiers and A/D (analog/digital) converters, and the computer simulation of radiation effects on microelectronic ISs.

Effect of packaging material on enological parameters and volatile compounds of dry white wine.

PubMed

Revi, M; Badeka, A; Kontakos, S; Kontominas, M G

2014-01-01

The enological parameters and volatile compounds of white wine packaged in dark coloured glass and two commercial bag-in-box (BIB) pouches (low density polyethylene - LDPE and ethylene vinyl acetate - EVA lined) were determined for a period of 6 months at 20 °C. Parameters monitored included: titratable acidity, volatile acidity, pH, total SO2, free SO2, colour, volatile compounds and sensory attributes. The BIB packaging materials affected the titratable acidity, total and free SO2 and colour of wine. A substantial portion of the wine aroma compounds was adsorbed by the plastic materials or lost to the environment through leakage of the valve fitment. Between the two plastics, the LDPE lined pouch showed a considerably higher aroma sorption as compared to EVA. Wine packaged in glass retained the largest portion of its aroma compounds. Sensory evaluation showed that white wine packaged in both plastics was of acceptable quality for 3 months vs. at least 6 months for that in glass bottles. Copyright © 2013 Elsevier Ltd. All rights reserved.

Unloading LDSD Test Device in Hawaii

NASA Image and Video Library

2014-05-28

The saucer-shaped test vehicle for NASA Low-Density Supersonic Decelerator LDSD project, packaged in the box shown here, was shipped via plane to the Navy Pacific Missile Range Facility in Kauai, Hawaii on April 17.

Effect of Packaging on Shelf-life and Lutein Content of Marigold (Tagetes erecta L.) Flowers.

PubMed

Pal, Sayani; Ghosh, Probir Kumar; Bhattacharjee, Paramita

2016-01-01

African marigold (Tagetes erecta L.) flowers are highly valued for their ornamental appeal as well as medicinal properties. However, their short shelf lives cause high post-harvest loss and limit their export potential. The review of patents and research articles revealed that different types of packaging designs/materials have been successfully employed for extension of shelf lives of cut flowers. The current work focuses on designing of different packaging configurations and selection of best configuration for preservation of marigold cut flowers. Ten packaging configurations, composed of four different packaging materials i.e., low density polyethylene (LDPE), polyethylene terephthalate, glassine paper and cellophane paper, were designed. Each pack, consisting of 20 ± 1 g of marigold flowers along with non-packaged control set were stored at 23 ± 2°C, 80% R.H., in an environmental chamber and the flowers were evaluated for their sensory attributes, phytochemical characteristics and physicochemical parameters of senescence to determine their shelf lives. Flowers packed in LDPE bag showed highest shelf life of 8 days with a lead of 4 days compared to control (shelf life - 4 days). This study also established for the first time the phenomenon of carotenogenesis in marigold cut flowers with significantly (P<0.01) higher production of lutein in LDPE packaged flowers. LDPE pack was the best design among the ten package designs, in preserving lutein content of marigold flowers and extending their shelf lives. This economically viable packaging can not only boost the export potential of this ornamental flower, but also allow utilization of nutraceutical potency of lutein.

Modelled Cost-Effectiveness of a Package Size Cap and a Kilojoule Reduction Intervention to Reduce Energy Intake from Sugar-Sweetened Beverages in Australia.

PubMed

Crino, Michelle; Herrera, Ana Maria Mantilla; Ananthapavan, Jaithri; Wu, Jason H Y; Neal, Bruce; Lee, Yong Yi; Zheng, Miaobing; Lal, Anita; Sacks, Gary

2017-09-06

Interventions targeting portion size and energy density of food and beverage products have been identified as a promising approach for obesity prevention. This study modelled the potential cost-effectiveness of: a package size cap on single-serve sugar sweetened beverages (SSBs) >375 mL ( package size cap ), and product reformulation to reduce energy content of packaged SSBs ( energy reduction ). The cost-effectiveness of each intervention was modelled for the 2010 Australia population using a multi-state life table Markov model with a lifetime time horizon. Long-term health outcomes were modelled from calculated changes in body mass index to their impact on Health-Adjusted Life Years (HALYs). Intervention costs were estimated from a limited societal perspective. Cost and health outcomes were discounted at 3%. Total intervention costs estimated in AUD 2010 were AUD 210 million. Both interventions resulted in reduced mean body weight ( package size cap : 0.12 kg; energy reduction : 0.23 kg); and HALYs gained ( package size cap : 73,883; energy reduction : 144,621). Cost offsets were estimated at AUD 750.8 million ( package size cap ) and AUD 1.4 billion ( energy reduction ). Cost-effectiveness analyses showed that both interventions were "dominant", and likely to result in long term cost savings and health benefits. A package size cap and kJ reduction of SSBs are likely to offer excellent "value for money" as obesity prevention measures in Australia.

Modelled Cost-Effectiveness of a Package Size Cap and a Kilojoule Reduction Intervention to Reduce Energy Intake from Sugar-Sweetened Beverages in Australia

PubMed Central

Mantilla Herrera, Ana Maria; Neal, Bruce; Zheng, Miaobing; Lal, Anita; Sacks, Gary

2017-01-01

Interventions targeting portion size and energy density of food and beverage products have been identified as a promising approach for obesity prevention. This study modelled the potential cost-effectiveness of: a package size cap on single-serve sugar sweetened beverages (SSBs) >375 mL (package size cap), and product reformulation to reduce energy content of packaged SSBs (energy reduction). The cost-effectiveness of each intervention was modelled for the 2010 Australia population using a multi-state life table Markov model with a lifetime time horizon. Long-term health outcomes were modelled from calculated changes in body mass index to their impact on Health-Adjusted Life Years (HALYs). Intervention costs were estimated from a limited societal perspective. Cost and health outcomes were discounted at 3%. Total intervention costs estimated in AUD 2010 were AUD 210 million. Both interventions resulted in reduced mean body weight (package size cap: 0.12 kg; energy reduction: 0.23 kg); and HALYs gained (package size cap: 73,883; energy reduction: 144,621). Cost offsets were estimated at AUD 750.8 million (package size cap) and AUD 1.4 billion (energy reduction). Cost-effectiveness analyses showed that both interventions were “dominant”, and likely to result in long term cost savings and health benefits. A package size cap and kJ reduction of SSBs are likely to offer excellent “value for money” as obesity prevention measures in Australia. PMID:28878175

The Origin of Salt-Encased Sediment Packages: Observations from the SE Precaspian Basin (Kazakhstan)

NASA Astrophysics Data System (ADS)

Fernandez, Naiara; Duffy, Oliver B.; Hudec, Michael R.; Jackson, Martin P. A.; Burg, George; Jackson, Christopher A.-L.; Dooley, Tim P.

2017-04-01

Intrasalt sediment packages containing siliciclastic sediments, carbonate sediments, or non-halite evaporites such as gypsum or anhydrite are common within most salt sequences. Intrasalt sediment packages may have been deposited before, during, or after salt deposition and be incorporated into the salt by various processes. Understanding the origin and evolution of intrasalt sediment packages may yield important insights into the tectonic and geodynamic history of the basin, and also into the understanding of salt tectonics. Despite the importance of intrasalt sediment packages, currently there is no systematic description of their possible origins and their distinguishing criteria. This work is divided in three parts. First, we outline the possible origins of intrasalt sediment packages, as well as criteria to determine if they originated as subsalt, suprasalt or intrasalt sequences. Second, we examine how sediment packages that originated on top of salt, such as minibasins, can be encased within salt. We propose four key processes by which salt can be expelled and emplaced above minibasins to encase them: a) salt expulsion from beneath a minibasin experiencing density-driven subsidence; b) salt expulsion from beneath adjacent subsiding minibasins; c) salt expulsion associated with lateral shortening; d) override of minibasins by a salt sheet sourced from elsewhere. Third, we present a case study from the SE Precaspian Basin, Kazakhstan, where, using a borehole-constrained 3D seismic reflection dataset, the proposed criteria are applied to an area with abundant, newly discovered sediment packages within salt.

Specificity of interactions among the DNA-packaging machine components of T4-related bacteriophages.

PubMed

Gao, Song; Rao, Venigalla B

2011-02-04

Tailed bacteriophages use powerful molecular motors to package the viral genome into a preformed capsid. Packaging at a rate of up to ∼2000 bp/s and generating a power density twice that of an automobile engine, the phage T4 motor is the fastest and most powerful reported to date. Central to DNA packaging are dynamic interactions among the packaging components, capsid (gp23), portal (gp20), motor (gp17, large "terminase"), and regulator (gp16, small terminase), leading to precise orchestration of the packaging process, but the mechanisms are poorly understood. Here we analyzed the interactions between small and large terminases of T4-related phages. Our results show that the gp17 packaging ATPase is maximally stimulated by homologous, but not heterologous, gp16. Multiple interaction sites are identified in both gp16 and gp17. The specificity determinants in gp16 are clustered in the diverged N- and C-terminal domains (regions I-III). Swapping of diverged region(s), such as replacing C-terminal RB49 region III with that of T4, switched ATPase stimulation specificity. Two specificity regions, amino acids 37-52 and 290-315, are identified in or near the gp17-ATPase "transmission" subdomain II. gp16 binding at these sites might cause a conformational change positioning the ATPase-coupling residues into the catalytic pocket, triggering ATP hydrolysis. These results lead to a model in which multiple weak interactions between motor and regulator allow dynamic assembly and disassembly of various packaging complexes, depending on the functional state of the packaging machine. This might be a general mechanism for regulation of the phage packaging machine and other complex molecular machines.

Sparsity-Based Super Resolution for SEM Images.

PubMed

Tsiper, Shahar; Dicker, Or; Kaizerman, Idan; Zohar, Zeev; Segev, Mordechai; Eldar, Yonina C

2017-09-13

The scanning electron microscope (SEM) is an electron microscope that produces an image of a sample by scanning it with a focused beam of electrons. The electrons interact with the atoms in the sample, which emit secondary electrons that contain information about the surface topography and composition. The sample is scanned by the electron beam point by point, until an image of the surface is formed. Since its invention in 1942, the capabilities of SEMs have become paramount in the discovery and understanding of the nanometer world, and today it is extensively used for both research and in industry. In principle, SEMs can achieve resolution better than one nanometer. However, for many applications, working at subnanometer resolution implies an exceedingly large number of scanning points. For exactly this reason, the SEM diagnostics of microelectronic chips is performed either at high resolution (HR) over a small area or at low resolution (LR) while capturing a larger portion of the chip. Here, we employ sparse coding and dictionary learning to algorithmically enhance low-resolution SEM images of microelectronic chips-up to the level of the HR images acquired by slow SEM scans, while considerably reducing the noise. Our methodology consists of two steps: an offline stage of learning a joint dictionary from a sequence of LR and HR images of the same region in the chip, followed by a fast-online super-resolution step where the resolution of a new LR image is enhanced. We provide several examples with typical chips used in the microelectronics industry, as well as a statistical study on arbitrary images with characteristic structural features. Conceptually, our method works well when the images have similar characteristics, as microelectronics chips do. This work demonstrates that employing sparsity concepts can greatly improve the performance of SEM, thereby considerably increasing the scanning throughput without compromising on analysis quality and resolution.

The experimental charge-density approach in the evaluation of intermolecular interactions. Application of a new module of the XD programming package to several solids including a pentapeptide.

PubMed

Abramov, Y A; Volkov, A; Wu, G; Coppens, P

2000-11-01

A new module interfaced to the XD programming package has been used in the evaluation of intermolecular interactions and lattice energies of the crystals of p-nitroaniline, L-asparagine monohydrate and the pentapeptide Boc-Gln-D-Iva-Hyp-Ala-Phol (Boc = butoxycarbonyl, Iva = isovaline = ethylalanine, Phol = phenylalaninol). The electrostatic interactions are evaluated with the atom-centered distributed multipoles from KRMM (kappa'-restricted multipole model) refinements, using the Buckingham expression for non-overlapping charge densities. Results for p-nitroaniline are compared with Hartree-Fock (HF), density functional (DFT) and Moller-Plesset (MP2) supermolecular calculations and with HF and DFT periodic calculations. The HF and DFT methods fail to predict the stability of the p-nitroaniline crystal but the results of the experimental charge-density approach (ECDA) are in good agreement with both MP2 interaction energies and the experimental lattice energy. ECDA results for L-asparagine monohydrate compare well with those from DFT supermolecular and periodic HF calculations. The disorder of the terminal group in the pentapeptide, which persists at the experimental temperature of 20 K, corresponds to an energy difference of only 0.35 kJ mol(-1), which is too small to be reproduced with current methods.

Reliability of CCGA 1152 and CCGA 1272 Interconnect Packages for Extreme Thermal Environments

NASA Technical Reports Server (NTRS)

Ramesham, Rajeshuni

2013-01-01

Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages of high interconnect density, very good thermal and electrical performance, and compatibility with standard surface-mount packaging assembly processes. CCGA packages are used in space applications such as in logics and microprocessor functions, telecommunications, flight avionics, and payload electronics. As these packages tend to have less solder joint strain relief than leaded packages, the reliability of CCGA packages is very important for short- and long-term space missions. Certain planetary satellites require operations of thermally uncontrolled hardware under extremely cold and hot temperatures with large diurnal temperature change from day to night. The planetary protection requires the hardware to be baked at +125 C for 72 hours to kill microbugs to avoid any biological contamination, especially for sample return missions. Therefore, the present CCGA package reliability research study has encompassed the temperature range of 185 to +125 C to cover various NASA deep space missions. Advanced 1152 and 1272 CCGA packaging interconnects technology test hardware objects have been subjected to ex treme temperature thermal cycles from 185 to +125 C. X-ray inspections of CCGA packages have been made before thermal cycling. No anomalous behavior and process problems were observed in the x-ray images. The change in resistance of the daisy-chained CCGA interconnects was measured as a function of increasing number of thermal cycles. Electrical continuity measurements of daisy chains have shown no anomalies, even until 596 thermal cycles. Optical inspections of hardware have shown a significant fatigue for CCGA 1152 packages over CCGA 1272 packages. No catastrophic failures have been observed yet in the results. Process qualification and assembly are required to optimize the CCGA assembly processes. Optical inspections of CCGA boards have been made after 258 and 596 thermal cycles. Corner columns have started showing significant fatigue per optical inspection results.

Image-analysis library

NASA Technical Reports Server (NTRS)

1980-01-01

MATHPAC image-analysis library is collection of general-purpose mathematical and statistical routines and special-purpose data-analysis and pattern-recognition routines for image analysis. MATHPAC library consists of Linear Algebra, Optimization, Statistical-Summary, Densities and Distribution, Regression, and Statistical-Test packages.

Design and simulation of a novel high-efficiency cooling heat-sink structure using fluid-thermodynamics

NASA Astrophysics Data System (ADS)

Hongqi, Jing; Li, Zhong; Yuxi, Ni; Junjie, Zhang; Suping, Liu; Xiaoyu, Ma

2015-10-01

A novel high-efficiency cooling mini-channel heat-sink structure has been designed to meet the package technology demands of high power density laser diode array stacks. Thermal and water flowing characteristics have been simulated using the Ansys-Fluent software. Owing to the increased effective cooling area, this mini-channel heat-sink structure has a better cooling effect when compared with the traditional macro-channel heat-sinks. Owing to the lower flow velocity in this novel high efficient cooling structure, the chillers' water-pressure requirement is reduced. Meanwhile, the machining process of this high-efficiency cooling mini-channel heat-sink structure is simple and the cost is relatively low, it also has advantages in terms of high durability and long lifetime. This heat-sink is an ideal choice for the package of high power density laser diode array stacks. Project supported by the Defense Industrial Technology Development Program (No. B1320133033).

Probing and monitoring aerosol and atmospheric clouds with an electro-optic oscillator.

PubMed

Arnon, S; Kopeika, N S

1996-09-20

Monitoring, probing, and sensing characteristics of aerosol clouds is difficult and complicated. Probing the characteristics of aerosols is most useful in the chemical and microelectronic industry for processing control of aerosols and emulsion, decreasing bit error rate in adaptive optical communication systems, and in acquiring data for atmospheric science and environment quality. We present a new mathematical and optical engineering model for monitoring characteristics of aerosol clouds. The model includes the temporal transfer function of aerosol clouds as a variable parameter in an electro-optic oscillator. The frequency of the oscillator changes according to changes in the characteristics of the clouds (density, size distribution, physical thickness, the medium and the particulate refractive indices, and spatial distribution). It is possible to measure only one free characteristic at a given time. An example of a practical system for monitoring the density of aerosol clouds is given. The frequency of the oscillator changes from 1.25 to 0.43 MHz for changes in aerosol density from 2000 to 3000 particulates cm(-3). The advantages of this new method compared with the transmissometer methods are (a) no necessity for line-of-sight measurement geometry, (b) accurate measurement of high optical thickness media is possible, (c) under certain conditions measurements can include characteristics of aerosol clouds related to light scatter that cannot be or are difficult to measure with a transmissometer, and (d) the cloud bandwidth for free space optical communication is directly measurable.

A Package of Information as the Planck Unit of Information and Also as a Fundamental Physical (Universal) Constant

NASA Astrophysics Data System (ADS)

Gholibeigian, Hassan

Dimension of information as the fifth dimension of the universe including packages of new information, is nested with space-time. Distributed density of information is matched on its correspondence distributed mater in space-time. Fundamental particle (string) like photon and graviton needs a package of information including its exact quantum state and law for process and travel a Planck length in a Planck time. This process is done via sub-particles (substrings). Processed information is carried by particle as the universe's history. My proposed formula for Planck unit of information (IP) and also for Fundamental Physical (Universal) Constant is: IP =lP ct P =1 Planck length lP, Planck time tP, and c , is light speed. Also my proposed formula for calculation of the packages is: I =tP- 1 . τ , in which, I is number of packages, and τ is lifetime of the particle. ``Communication of information'' as a ``fundamental symmetry'' leads phenomena. Packages should be always up to date including new information for evolution of the Universe. But, where come from or how are created new information which Hawking and his colleagues forgot it bring inside the black hole and leave it behind the horizon in form of soft hair?

High temperature insulation materials for reradiative thermal protection systems

NASA Technical Reports Server (NTRS)

Hughes, T. A.

1972-01-01

Results are presented of a two year program to evaluate packaged thermal insulations for use under a metallic radiative TPS of a shuttle orbiter vehicle. Evaluations demonstrated their survival for up to 100 mission reuse cycles under shuttle acoustic and thermal loads with peak temperatures of 1000 F, 1800 F, 2000 F, 2200 F and 2500 F. The specimens were composed of low density refractory fiber felts, packaged in thin gage metal foils. In addition, studies were conducted on the venting requirements of the packages, salt spray resistance of the metal foils, and the thermal conductivity of many of the insulations as a function of temperature and ambient air pressure. Data is also presented on the radiant energy transport through insulations, and back-scattering coefficients were experimentally determined as a function of source temperature.

Integrated Avionics System (IAS)

NASA Technical Reports Server (NTRS)

Hunter, D. J.

2001-01-01

As spacecraft designs converge toward miniaturization and with the volumetric and mass constraints placed on avionics, programs will continue to advance the 'state of the art' in spacecraft systems development with new challenges to reduce power, mass, and volume. Although new technologies have improved packaging densities, a total system packaging architecture is required that not only reduces spacecraft volume and mass budgets, but increase integration efficiencies, provide modularity and scalability to accommodate multiple missions. With these challenges in mind, a novel packaging approach incorporates solutions that provide broader environmental applications, more flexible system interconnectivity, scalability, and simplified assembly test and integration schemes. This paper will describe the fundamental elements of the Integrated Avionics System (IAS), Horizontally Mounted Cube (HMC) hardware design, system and environmental test results. Additional information is contained in the original extended abstract.

Fundamental study of microelectronic chip response under laser ultrasonic-interferometric inspection using C-scan method

NASA Astrophysics Data System (ADS)

Yang, Lei; Gong, Jie; Ume, I. Charles

2014-02-01

In modern surface mount packaging technologies, such as flip chips, chip scale packages, and ball grid arrays(BGA), chips are attached to the substrates/printed wiring board (PWB) using solder bump interconnections. The quality of solder bumps between the chips and the substrate/board is difficult to inspect. Laser ultrasonic-interferometric technique was proved to be a promising approach for solder bump inspection because of its noncontact and nondestructive characteristics. Different indicators extracted from received signals have been used to predict the potential defects, such as correlation coefficient, error ratio, frequency shifting, etc. However, the fundamental understanding of the chip behavior under laser ultrasonic inspection is still missing. Specifically, it is not sure whether the laser interferometer detected out-of-plane displacements were due to wave propagation or structural vibration when the chip was excited by pulsed laser. Plus, it is found that the received signals are chip dependent. Both challenges impede the interpretation of acquired signals. In this paper, a C-scan method was proposed to study the underlying phenomenon during laser ultrasonic inspection. The full chip was inspected. The response of the chip under laser excitation was visualized in a movie resulted from acquired signals. Specifically, a BGA chip was investigated to demonstrate the effectiveness of this method. By characterizing signals using discrete wavelet transform(DWT), both ultrasonic wave propagation and vibration were observed. Separation of them was successfully achieved using ideal band-pass filter and visualized in resultant movies, too. The observed ultrasonic waves were characterized and their respective speeds were measured by applying 2-D FFT. The C-scan method, combined with different digital signal processing techniques, was proved to be an very effective methodology to learn the behavior of chips under laser excitation. This general procedure can be applied to any unknown chip before inspection. A wealth of information can be provided by this learning procedure, which greatly benefits the interpretation of inspection signals afterwards.

Influence of some packaging materials and of natural tocopherols on the sensory properties of breakfast cereals.

PubMed

Paradiso, Vito M; Caponio, Francesco; Summo, Carmine; Gomes, Tommaso

2014-04-01

The combined effect of natural antioxidants and packaging materials on the quality decay of breakfast cereals during storage was evaluated. Corn flakes were produced on industrial scale, using different packages and adding natural tocopherols to the ingredients, and stored for 1 year. The samples were then submitted to sensory analysis and HS-solid phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) analysis. The packaging had a significant influence on the sensory profile of the aged product: metallized polypropylene gave the highest levels of oxidation compounds and sensory defects. The sensory profile was improved using polypropylene and especially high-density polyethylene. Natural tocopherols reduced the sensory decay of the flakes and the oxidative evolution of the volatile profile. They gave the most remarkable improvement in polypropylene (either metallized or not) packs. Polypropylene showed a barrier effect on the scalping of volatiles outside of the pack. This led to higher levels of oxidation volatiles and faster rates of the further oxidative processes involving the volatiles.

Starch-based Antimicrobial Films Incorporated with Lauric Acid and Chitosan

NASA Astrophysics Data System (ADS)

Salleh, E.; Muhamad, I. I.

2010-03-01

Antimicrobial (AM) packaging is one of the most promising active packaging systems. Starch-based film is considered an economical material for antimicrobial packaging. This study aimed at the development of food packaging based on wheat starch incorporated with lauric acid and chitosan as antimicrobial agents. The purpose is to restrain or inhibit the growth of spoilage and/or pathogenic microorganisms that are contaminating foods. The antimicrobial effect was tested on B. substilis and E. coli. Inhibition of bacterial growth was examined using two methods, i.e. zone of inhibition test on solid media and liquid culture test (optical density measurements). The control and AM films (incorporated with chitosan and lauric acid) were produced by casting method. From the observations, AM films exhibited inhibitory zones. Interestingly, a wide clear zone on solid media was observed for B. substilis growth inhibition whereas inhibition for E. coli was not as effective as B. substilis. From the liquid culture test, the AM films clearly demonstrated a better inhibition against B. substilis than E. coli.

Rocket-borne thermal plasma instrument "MIPEX" for the ionosphere D, E layer in-situ measurements

NASA Astrophysics Data System (ADS)

Fang, H. K.; Chen, A. B. C.; Lin, C. C. H.; Wu, T. J.; Liu, K. S.; Chuang, C. W.

2017-12-01

In this presentation, the design concepts, performances and status of a thermal plasma particle instrument package "Mesosphere and Ionosphere Plasma Exploration complex (MIPEX)", which is going to be installed onboard a NSPO-funded hybrid rocket, to investigate the electrodynamic processes in ionosphere D, E layers above Taiwan are reported. MIPEX is capable of measuring plasma characteristics including ion temperature, ion composition, ion drift, electron temperature and plasma density at densities as low as 1-10 cm-1. This instrument package consists of an improved retarding potential analyzer with a channel electron multiplier (CEM), a simplified ion drift meter and a planar Langmuir probe. To achieve the working atmospheric pressure of CEM at the height of lower D layer ( 70km), a portable vacuum pump is also placed in the package. A prototype set of the MIPEX has been developed and tested in the Space Plasma Operation Chamber (SPOC) at NCKU, where in ionospheric plasma is generated by back-diffusion plasma sources. A plasma density of 10-106 cm-1, ion temperature of 300-1500 K and electron temperature of 1000-3000K is measured and verified. Limited by the flight platform and the performance of the instruments, the in-situ plasma measurements at the Mesosphere and lower Thermosphere is very challenging and rare. MIPEX is capable of extending the altitude of the effective plasma measurement down to 70 km height and this experiment can provide unique high-quality data of the plasma environment to explore the ion distribution and the electrodynamic processes in the Ionosphere D, E layers at dusk.

Reliability Considerations of ULP Scaled CMOS in Spacecraft Systems

NASA Technical Reports Server (NTRS)

White, Mark; MacNeal, Kristen; Cooper, Mark

2012-01-01

NASA, the aerospace community, and other high reliability (hi-rel) users of advanced microelectronic products face many challenges as technology continues to scale into the deep sub-micron region. Decreasing the feature size of CMOS devices not only allows more components to be placed on a single chip, but it increases performance by allowing faster switching (or clock) speeds with reduced power compared to larger scaled devices. Higher performance, and lower operating and stand-by power characteristics of Ultra-Low Power (ULP) microelectronics are not only desirable, but also necessary to meet low power consumption design goals of critical spacecraft systems. The integration of these components in such systems, however, must be balanced with the overall risk tolerance of the project.

Geckoprinting: assembly of microelectronic devices on unconventional surfaces by transfer printing with isolated gecko setal arrays

PubMed Central

Jeong, Jaeyoung; Kim, Juho; Song, Kwangsun; Autumn, Kellar; Lee, Jongho

2014-01-01

Developing electronics in unconventional forms provides opportunities to expand the use of electronics in diverse applications including bio-integrated or implanted electronics. One of the key challenges lies in integrating semiconductor microdevices onto unconventional substrates without glue, high pressure or temperature that may cause damage to microdevices, substrates or interfaces. This paper describes a solution based on natural gecko setal arrays that switch adhesion mechanically on and off, enabling pick and place manipulation of thin microscale semiconductor materials onto diverse surfaces including plants and insects whose surfaces are usually rough and irregular. A demonstration of functional ‘geckoprinted’ microelectronic devices provides a proof of concept of our results in practical applications. PMID:25056216

Single-event effects experienced by astronauts and microelectronic circuits flown in space

DOE Office of Scientific and Technical Information (OSTI.GOV)

McNulty, P.J.

Models developed for explaining the light flashes experienced by astronauts on Apollo and Skylab missions were used with slight modification to explain upsets observed in microelectronic circuits. Both phenomena can be explained by the simple assumption that an event occurs whenever a threshold number of ionizations or isomerizations are generated within a sensitive volume. Evidence is consistent with the threshold being sharp in both cases, but fluctuations in the physical stimuli lead to a gradual rather than sharp increase in cross section with LET. Successful use of the model requires knowledge of the dimensions of the sensitive volume and themore » value of threshold. Techniques have been developed to determine these SEU parameters in modern circuits.« less

The 88-Inch Cyclotron: A One-Stop Facility for Electronics Radiation and Detector Testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kireeff Covo, M.; Albright, R. A.; Ninemire, B. F.

In outer space down to the altitudes routinely flown by larger aircrafts, radiation can pose serious issues for microelectronics circuits. The 88-Inch Cyclotron at Lawrence Berkeley National Laboratory is a sector-focused cyclotron and home of the Berkeley Accelerator Space Effects Facility, where the effects of energetic particles on sensitive microelectronics are studied with the goal of designing electronic systems for the space community. This paper describes the flexibility of the facility and its capabilities for testing the bombardment of electronics by heavy ions, light ions, and neutrons. Experimental capabilities for the generation of neutron beams from deuteron breakups and radiationmore » testing of carbon nanotube field effect transistor will be discussed.« less

Ceramic materials of low-temperature synthesis for dielectric coating applied by 3D aerosol printing used in nano- and microelectronics, lighting engineering, and spacecraft control devices

NASA Astrophysics Data System (ADS)

Ivanov, A. A.; Tuev, V. I.; Nisan, A. V.; Potapov, G. N.

2016-11-01

A synthesis technique of low-temperature ceramic material based on aluminosilicates of dendrimer morphology capable to contain up to 80 wt % of nitrides and oxides of high-melting compounds as filler has been developed. The synthesis is based on a sol-gel method followed by mechanochemical treatment and ultrasonic dispersing. Dielectric ceramic layers with the layer thickness in the nanometer range and high thermal conductivity have been obtained for the first time by 3D aerosol printing of the synthesized material. The study of the obtained ceramic coating on the metal surface (Al) has proved its use prospects in microelectronics, light engineering, and devices for special purposes.

Thin film microelectronics materials production in the vacuum of space

NASA Astrophysics Data System (ADS)

Ignatiev, A.; Sterling, M.; Horton, C.; Freundlich, A.; Pei, S.; Hill, R.

1997-01-01

The international Space Station era will open up a new dimension in the use of one of the unique attributes of space, vacuum, for the production of advanced semiconductor materials and devices for microelectronics applications. Ultra-vacuum is required for the fabrication in thin film form of high quality semiconductors. This can be accomplished behind a free flying platform similar to the current Wake Shield Facility which is specifically designed to support in-space production. The platform will require apparatus for thin film growth, a robotics interface to allow for the change out of raw materials and the harvesting of finished product, and a servicing plant incorporating Space Station that will support long-term utilization of the platform.

Breaking the electrical barrier between copper and carbon nanotubes.

PubMed

Milowska, Karolina Z; Ghorbani-Asl, Mahdi; Burda, Marek; Wolanicka, Lidia; Ćatić, Nordin; Bristowe, Paul D; Koziol, Krzysztof K K

2017-06-22

Improving the interface between copper and carbon nanotubes (CNTs) offers a straightforward strategy for the effective manufacturing and utilisation of Cu-CNT composite material that could be used in various industries including microelectronics, aerospace and transportation. Motivated by a combination of structural and electrical measurements on Cu-M-CNT bimetal systems (M = Ni, Cr) we show, using first principles calculations, that the conductance of this composite can exceed that of a pure Cu-CNT system and that the current density can even reach 10 11 A cm -2 . The results show that the proper choice of alloying element (M) and type of contact facilitate the fabrication of ultra-conductive Cu-M-CNT systems by creating a favourable interface geometry, increasing the interface electronic density of states and reducing the contact resistance. In particular, a small concentration of Ni between the Cu matrix and the CNT using either an "end contact" and or a "dot contact" can significantly improve the electrical performance of the composite. Furthermore the predicted conductance of Ni-doped Cu-CNT "carpets" exceeds that of an undoped system by ∼200%. Cr is shown to improve CNT integration and composite conductance over a wide temperature range while Al, at low voltages, can enhance the conductance beyond that of Cr.

Low Temperature and Modified Atmosphere: Hurdles for Antibiotic Resistance Transfer?

PubMed

Van Meervenne, Eva; Van Coillie, Els; Van Weyenberg, Stephanie; Boon, Nico; Herman, Lieve; Devlieghere, Frank

2015-12-01

Food is an important dissemination route for antibiotic-resistant bacteria. Factors used during food production and preservation may contribute to the transfer of antibiotic resistance genes, but research on this subject is scarce. In this study, the effect of temperature (7 to 37°C) and modified atmosphere packaging (air, 50% CO2-50% N2, and 100% N2) on antibiotic resistance transfer from Lactobacillus sakei subsp. sakei to Listeria monocytogenes was evaluated. Filter mating was performed on nonselective agar plates with high-density inocula. A more realistic setup was created by performing modified atmosphere experiments on cooked ham using high-density and low-density inocula. Plasmid transfer was observed between 10 and 37°C, with plasmid transfer also observed at 7°C during a prolonged incubation period. When high-density inocula were used, transconjugants were detected, both on agar plates and cooked ham, under the three atmospheres (air, 50% CO2-50% N2, and 100% N2) at 7°C. This yielded a median transfer ratio (number of transconjugants/number of recipients) with an order of magnitude of 10(-4) to 10(-6). With low-density inocula, transfer was only detected under the 100% N2 atmosphere after 10-day incubation at 7°C, yielding a transfer ratio of 10(-5). Under this condition, the highest bacterial density was obtained. The results indicate that low temperature and modified atmosphere packaging, two important hurdles in the food industry, do not necessarily prevent plasmid transfer from Lactobacillus sakei subsp. sakei to Listeria monocytogenes.

Facility safety study

NASA Technical Reports Server (NTRS)

1979-01-01

The safety of NASA's in house microelectronics facility is addressed. Industrial health standards, facility emission control requirements, operation and safety checklists, and the disposal of epitaxial vent gas are considered.

JPRS report. Science and technology: Europe and Latin America

NASA Astrophysics Data System (ADS)

1987-12-01

Topics addressed include: advanced materials; aerospace; civil aviation; automative industry; biotechnology; computers; metallurgical industries; microelectronics; science and technology policy; and lasers, sensor, and optics.

Polyethylene glycol grafted polyethylene: a versatile platform for nonmigratory active packaging applications.

PubMed

Barish, Jeffrey A; Goddard, Julie M

2011-01-01

Nonmigratory active packaging, in which bioactive components are tethered to the package, offers the potential to reduce the need for additives in food products while maintaining safety and quality. A challenge in developing nonmigratory active packaging materials is the loss of biomolecular activity that can occur when biomolecules are immobilized. In this work, we describe a method in which a biocompatible polymer (polyethylene glycol, PEG) is grafted from the surface of ozone-treated low-density polyethylene (LDPE) resulting in a surface functionalized polyethylene to which a range of amine-terminated bioactive molecules can be immobilized. Free radical graft polymerization is used to graft PEG onto the LDPE surface, followed by immobilization of ethylenediamine onto the PEG tether. Ethylenediamine was used to demonstrate that amine-terminated molecules could be covalently attached to the PEG-grafted film. Changes in surface chemistry and topography were measured by attenuated total reflectance Fourier transform infrared spectroscopy, contact angle, atomic force microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. We demonstrate the ability to graft PEG onto the surface of polymer packaging films by free radical graft polymerization, and to covalently link an amine-terminated molecule to the PEG tether, demonstrating that amine-terminated bioactive compounds (such as peptides, enzymes, and some antimicrobials) can be immobilized onto PEG-grafted LDPE in the development of nonmigratory active packaging.   Nonmigratory active packaging offers the potential for improving food safety and quality while minimizing the migration of the active agent into food. In this paper, we describe a technique to modify polyethylene packaging films such that active agents can be covalently immobilized by a biocompatible tether. Such a technique can be adapted to a number of applications such as antimicrobial, antioxidant, or immobilized enzyme active packaging. © 2011 Institute of Food Technologists®

The equation of state package FEOS for high energy density matter

NASA Astrophysics Data System (ADS)

Faik, Steffen; Tauschwitz, Anna; Iosilevskiy, Igor

2018-06-01

Adequate equation of state (EOS) data is of high interest in the growing field of high energy density physics and especially essential for hydrodynamic simulation codes. The semi-analytical method used in the newly developed Frankfurt equation of state (FEOS) package provides an easy and fast access to the EOS of - in principle - arbitrary materials. The code is based on the well known QEOS model (More et al., 1988; Young and Corey, 1995) and is a further development of the MPQeos code (Kemp and Meyer-ter Vehn, 1988; Kemp and Meyer-ter Vehn, 1998) from Max-Planck-Institut für Quantenoptik (MPQ) in Garching Germany. The list of features contains the calculation of homogeneous mixtures of chemical elements and the description of the liquid-vapor two-phase region with or without a Maxwell construction. Full flexibility of the package is assured by its structure: A program library provides the EOS with an interface designed for Fortran or C/C++ codes. Two additional software tools allow for the generation of EOS tables in different file output formats and for the calculation and visualization of isolines and Hugoniot shock adiabats. As an example the EOS of fused silica (SiO2) is calculated and compared to experimental data and other EOS codes.

The fate of a toxigenic strain of Staphylococcus aureus in vacuum-packaged bacon.

PubMed

Dempster, J F; Kelly, W R

1973-09-01

Pork was cured by (a) the Wiltshire method and (b) a hygienic sweet cure process. Representative samples of both bacons were inoculated at ;low' density (10(3) organisms/g.) and ;high' density (10(6) organisms/g.) with a toxin-producing strain of Staphylococcus aureus, ;High' and ;low' density samples of both bacons were each stored at 5 degrees C. for 42 days and 15 degrees C. for 21 days.Results indicated that the test organism at high inoculum density grew slowly in both bacons at 5 degrees C. The organism survived at 5 degrees C. in both ;low density' bacons. At 15 degrees C. the test organism grew; growth being more pronounced in the ;hygienic' than in Wiltshire bacon.

flexsurv: A Platform for Parametric Survival Modeling in R

PubMed Central

Jackson, Christopher H.

2018-01-01

flexsurv is an R package for fully-parametric modeling of survival data. Any parametric time-to-event distribution may be fitted if the user supplies a probability density or hazard function, and ideally also their cumulative versions. Standard survival distributions are built in, including the three and four-parameter generalized gamma and F distributions. Any parameter of any distribution can be modeled as a linear or log-linear function of covariates. The package also includes the spline model of Royston and Parmar (2002), in which both baseline survival and covariate effects can be arbitrarily flexible parametric functions of time. The main model-fitting function, flexsurvreg, uses the familiar syntax of survreg from the standard survival package (Therneau 2016). Censoring or left-truncation are specified in ‘Surv’ objects. The models are fitted by maximizing the full log-likelihood, and estimates and confidence intervals for any function of the model parameters can be printed or plotted. flexsurv also provides functions for fitting and predicting from fully-parametric multi-state models, and connects with the mstate package (de Wreede, Fiocco, and Putter 2011). This article explains the methods and design principles of the package, giving several worked examples of its use. PMID:29593450

Optomechanical Design and Characterization of a Printed-Circuit-Board-Based Free-Space Optical Interconnect Package

NASA Astrophysics Data System (ADS)

Zheng, Xuezhe; Marchand, Philippe J.; Huang, Dawei; Kibar, Osman; Ozkan, Nur S. E.; Esener, Sadik C.

1999-09-01

We present a proof of concept and a feasibility demonstration of a practical packaging approach in which free-space optical interconnects (FSOI s) can be integrated simply on electronic multichip modules (MCM s) for intra-MCM board interconnects. Our system-level packaging architecture is based on a modified folded 4 f imaging system that has been implemented with only off-the-shelf optics, conventional electronic packaging, and passive-assembly techniques to yield a potentially low-cost and manufacturable packaging solution. The prototypical system as built supports 48 independent FSOI channels with 8 separate laser and detector chips, for which each chip consists of a one-dimensional array of 12 devices. All the chips are assembled on a single substrate that consists of a printed circuit board or a ceramic MCM. Optical link channel efficiencies of greater than 90% and interchannel cross talk of less than 20 dB at low frequency have been measured. The system is compact at only 10 in. 3 (25.4 cm 3 ) and is scalable, as it can easily accommodate additional chips as well as two-dimensional optoelectronic device arrays for increased interconnection density.

Chip-scale thermal management of high-brightness LED packages

NASA Astrophysics Data System (ADS)

Arik, Mehmet; Weaver, Stanton

2004-10-01

The efficiency and reliability of the solid-state lighting devices strongly depend on successful thermal management. Light emitting diodes, LEDs, are a strong candidate for the next generation, general illumination applications. LEDs are making great strides in terms of lumen performance and reliability, however the barrier to widespread use in general illumination still remains the cost or $/Lumen. LED packaging designers are pushing the LED performance to its limits. This is resulting in increased drive currents, and thus the need for lower thermal resistance packaging designs. As the power density continues to rise, the integrity of the package electrical and thermal interconnect becomes extremely important. Experimental results with high brightness LED packages show that chip attachment defects can cause significant thermal gradients across the LED chips leading to premature failures. A numerical study was also carried out with parametric models to understand the chip active layer temperature profile variation due to the bump defects. Finite element techniques were utilized to evaluate the effects of localized hot spots at the chip active layer. The importance of "zero defects" in one of the more popular interconnect schemes; the "epi down" soldered flip chip configuration is investigated and demonstrated.

Porous Diblock Copolymer Thin Films in High-Performance Semiconductor Microelectronics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Black, C.T.

2011-02-01

The engine fueling more than 40 years of performance improvements in semiconductor integrated circuits (ICs) has been industry's ability to pattern circuit elements at ever-higher resolution and with ever-greater precision. Steady advances in photolithography - the process wherein ultraviolet light chemically changes a photosensitive polymer resist material in order to create a latent image - have resulted in scaling of minimum printed feature sizes from tens of microns during the 1980s to sub-50 nanometer transistor gate lengths in today's state-of-the-art ICs. The history of semiconductor technology scaling as well as future technology requirements is documented in the International Technology Roadmapmore » for Semiconductors (ITRS). The progression of the semiconductor industry to the realm of nanometer-scale sizes has brought enormous challenges to device and circuit fabrication, rendering performance improvements by conventional scaling alone increasingly difficult. Most often this discussion is couched in terms of field effect transistor (FET) feature sizes such as the gate length or gate oxide thickness, however these challenges extend to many other aspects of the IC, including interconnect dimensions and pitch, device packing density, power consumption, and heat dissipation. The ITRS Technology Roadmap forecasts a difficult set of scientific and engineering challenges with no presently-known solutions. The primary focus of this chapter is the research performed at IBM on diblock copolymer films composed of polystyrene (PS) and poly(methyl-methacrylate) (PMMA) (PS-b-PMMA) with total molecular weights M{sub n} in the range of {approx}60K (g/mol) and polydispersities (PD) of {approx}1.1. These materials self assemble to form patterns having feature sizes in the range of 15-20nm. PS-b-PMMA was selected as a self-assembling patterning material due to its compatibility with the semiconductor microelectronics manufacturing infrastructure, as well as the significant body of existing research on understanding its material properties.« less

Thomson backscattering diagnostics of nanosecond electron bunches in high space charge regime

NASA Astrophysics Data System (ADS)

Plachinda, Pavel

The trend over the last 50 years of down-scaling the silicon transistor to achieve faster computations has led to doubling of the number of transistors and computation speed over about every two years. However, this trend cannot be maintained due to the fundamental limitations of silicon as the main material for the semiconducting industry. Therefore, there is an active search for exploration of alternate materials. Among the possible candidates that can may be able to replace silicon is graphene which has recently gained the most attention. Unique properties of graphene include exceedingly high carrier mobility, tunable band gap, huge optical density of a monolayer, anomalous quantum Hall effect, and many others. To be suitable for microelectronic applications the material should be semiconductive, i.e. have a non-zero band gap. Pristine graphene is a semimetal, but by the virtue of doping the graphene surface with different molecules and radicals a band gap can be opened. Because the electronic properties of all materials are intimately related to their atomic structure, characterization of molecular and electronic structure of functionalizing groups is of high interest. The ab-inito (from the first principles) calculations provide a unique opportunity to study the influence of the dopants and thus allow exploration of the physical phenomena in functionalized graphene structures. This ability paves the road to probe the properties based on the intuitive structural information only. A great advantage of this approach lies in the opportunity for quick screening of various atomic structures. We conducted a series of ab-inito investigations of graphene functionalized with covalently and hapticly bound groups, and demonstrated possible practical usage of functionalized graphene for microelectronic and optical applications. This investigation showed that it is possible produce band gaps in graphene (i.e., produce semiconducting graphene) of about 1 eV, without degrading the carrier mobility. This was archived by considering the influence of those adducts on electronic band structure and conductivity properties.

Advanced Microelectronics Technologies for Future Small Satellite Systems

NASA Technical Reports Server (NTRS)

Alkalai, Leon

1999-01-01

Future small satellite systems for both Earth observation as well as deep-space exploration are greatly enabled by the technological advances in deep sub-micron microelectronics technologies. Whereas these technological advances are being fueled by the commercial (non-space) industries, more recently there has been an exciting new synergism evolving between the two otherwise disjointed markets. In other words, both the commercial and space industries are enabled by advances in low-power, highly integrated, miniaturized (low-volume), lightweight, and reliable real-time embedded systems. Recent announcements by commercial semiconductor manufacturers to introduce Silicon On Insulator (SOI) technology into their commercial product lines is driven by the need for high-performance low-power integrated devices. Moreover, SOI has been the technology of choice for many space semiconductor manufacturers where radiation requirements are critical. This technology has inherent radiation latch-up immunity built into the process, which makes it very attractive to space applications. In this paper, we describe the advanced microelectronics and avionics technologies under development by NASA's Deep Space Systems Technology Program (also known as X2000). These technologies are of significant benefit to both the commercial satellite as well as the deep-space and Earth orbiting science missions. Such a synergistic technology roadmap may truly enable quick turn-around, low-cost, and highly capable small satellite systems for both Earth observation as well as deep-space missions.

Vertical and bevel-structured SiC etching techniques incorporating different gas mixture plasmas for various microelectronic applications.

PubMed

Sung, Ho-Kun; Qiang, Tian; Yao, Zhao; Li, Yang; Wu, Qun; Lee, Hee-Kwan; Park, Bum-Doo; Lim, Woong-Sun; Park, Kyung-Ho; Wang, Cong

2017-06-20

This study presents a detailed fabrication method, together with validation, discussion, and analysis, for state-of-the-art silicon carbide (SiC) etching of vertical and bevelled structures by using inductively coupled plasma reactive ion etching (ICP-RIE) for microelectronic applications. Applying different gas mixtures, a maximum bevel angle of 87° (almost vertical), large-angle bevels ranging from 40° to 80°, and small-angel bevels ranging from 7° to 17° were achieved separately using distinct gas mixtures at different ratios. We found that SF 6 with additive O 2 was effective for vertical etching, with a best etching rate of 3050 Å/min. As for the large-angle bevel structures, BCl 3  + N 2 gas mixtures show better characteristics, exhibiting a controllable and large etching angle range from 40° to 80° through the adjustment of the mixture ratio. Additionally, a Cl 2  + O 2 mixture at different ratios is applied to achieve a small-angel bevels ranging from 7° to 17°. A minimum bevel angel of approximately 7° was achieved under the specific volume of 2.4 sccm Cl 2 and 3.6 sccm O 2 . These results can be used to improve performance in various microelectronic applications including MMIC via holes, PIN diodes, Schottky diodes, JFETs' bevel mesa, and avalanche photodiode fabrication.

Atomically Thin Al2O3 Films for Tunnel Junctions

NASA Astrophysics Data System (ADS)

Wilt, Jamie; Gong, Youpin; Gong, Ming; Su, Feifan; Xu, Huikai; Sakidja, Ridwan; Elliot, Alan; Lu, Rongtao; Zhao, Shiping; Han, Siyuan; Wu, Judy Z.

2017-06-01

Metal-insulator-metal tunnel junctions are common throughout the microelectronics industry. The industry standard AlOx tunnel barrier, formed through oxygen diffusion into an Al wetting layer, is plagued by internal defects and pinholes which prevent the realization of atomically thin barriers demanded for enhanced quantum coherence. In this work, we employ in situ scanning tunneling spectroscopy along with molecular-dynamics simulations to understand and control the growth of atomically thin Al2O3 tunnel barriers using atomic-layer deposition. We find that a carefully tuned initial H2O pulse hydroxylated the Al surface and enabled the creation of an atomically thin Al2O3 tunnel barrier with a high-quality M -I interface and a significantly enhanced barrier height compared to thermal AlOx . These properties, corroborated by fabricated Josephson junctions, show that atomic-layer deposition Al2O3 is a dense, leak-free tunnel barrier with a low defect density which can be a key component for the next generation of metal-insulator-metal tunnel junctions.

The effects of electron and hole transport layer with the electrode work function on perovskite solar cells

NASA Astrophysics Data System (ADS)

Deng, Quanrong; Li, Yiqi; Chen, Lian; Wang, Shenggao; Wang, Geming; Sheng, Yonglong; Shao, Guosheng

2016-09-01

The effects of electron and hole transport layer with the electrode work function on perovskite solar cells with the interface defects were simulated by using analysis of microelectronic and photonic structures-one-dimensional (AMPS-1D) software. The simulation results suggest that TiO2 electron transport layer provides best device performance with conversion efficiency of 25.9% compared with ZnO and CdS. The threshold value of back electrode work function for Spiro-OMeTAD, NiO, CuI and Cu2O hole transport layer are calculated to be 4.9, 4.8, 4.7 and 4.9 eV, respectively, to reach the highest conversion efficiency. The mechanisms of device physics with various electron and hole transport materials are discussed in details. The device performance deteriorates gradually as the increased density of interface defects located at ETM/absorber or absorber/HTM. This research results can provide helpful guidance for materials and metal electrode choice for perovskite solar cells.

Ring modulators with enhanced efficiency based on standing-wave operation on a field-matched, interdigitated p-n junction.

PubMed

Pavanello, Fabio; Zeng, Xiaoge; Wade, Mark T; Popović, Miloš A

2016-11-28

We propose ring modulators based on interdigitated p-n junctions that exploit standing rather than traveling-wave resonant modes to improve modulation efficiency, insertion loss and speed. Matching the longitudinal nodes and antinodes of a standing-wave mode with high (contacts) and low (depletion regions) carrier density regions, respectively, simultaneously lowers loss and increases sensitivity significantly. This approach permits further to relax optical constraints on contacts placement and can lead to lower device capacitance. Such structures are well-matched to fabrication in advanced microelectronics CMOS processes. Device architectures that exploit this concept are presented along with their benefits and drawbacks. A temporal coupled mode theory model is used to investigate the static and dynamic response. We show that modulation efficiencies or loss Q factors up to 2 times higher than in previous traveling-wave geometries can be achieved leading to much larger extinction ratios. Finally, we discuss more complex doping geometries that can improve carrier dynamics for higher modulation speeds in this context.

Reactive ion etching of indium-tin oxide films by CCl4-based Inductivity Coupled Plasma

NASA Astrophysics Data System (ADS)

Juneja, Sucheta; Poletayev, Sergey D.; Fomchenkov, Sergey; Khonina, Svetlana N.; Skidanov, Roman V.; Kazanskiy, Nikolay L.

2016-08-01

Indium tin oxide (ITO) films have been a subject of extensive studies in fabrication of micro-electronic devices for opto-electronic applications ranging from anti-reflection coatings to transparent contacts in photovoltaic devices. In this paper, a new and effective way of reactive ion etching of a conducting indium-tin oxide (ITO) film with Carbon tetrachloride (CCl4) has been investigated. CCl4 plasma containing an addition of gases mixture of dissociated argon and oxygen were used. Oxygen is added to increase the etchant percentage whereas argon was used for stabilization of plasma. The etching characteristics obtained with these gaseous mixtures were explained based on plasma etch chemistry and etching regime of ITO films. An etch rate as high as ∼20 nm/min can be achieved with a controlled process parameter such as power density, total flow rate, composition of reactive gases gas and pressure. Our Investigation represents some of the extensive work in this area.

Effects of a chirped bias voltage on ion energy distributions in inductively coupled plasma reactors

NASA Astrophysics Data System (ADS)

Lanham, Steven J.; Kushner, Mark J.

2017-08-01

The metrics for controlling reactive fluxes to wafers for microelectronics processing are becoming more stringent as feature sizes continue to shrink. Recent strategies for controlling ion energy distributions to the wafer involve using several different frequencies and/or pulsed powers. Although effective, these strategies are often costly or present challenges in impedance matching. With the advent of matching schemes for wide band amplifiers, other strategies to customize ion energy distributions become available. In this paper, we discuss results from a computational investigation of biasing substrates using chirped frequencies in high density, electronegative inductively coupled plasmas. Depending on the frequency range and chirp duration, the resulting ion energy distributions exhibit components sampled from the entire frequency range. However, the chirping process also produces transient shifts in the self-generated dc bias due to the reapportionment of displacement and conduction with frequency to balance the current in the system. The dynamics of the dc bias can also be leveraged towards customizing ion energy distributions.

Dielectric cracking produced by electromigration in microelectronic interconnects

NASA Astrophysics Data System (ADS)

Chiras, S.; Clarke, D. R.

2000-12-01

The development of stress during electromigration along Al lines, constrained within a dielectric in a coplanar test configuration, is measured. It is shown that, above a certain threshold current density, cracking of the dielectric is induced in the vicinity of the anode. Cracking of the dielectric leads to loss of mechanical constraint on the aluminum conductor which, in turn, leads to increases in electrical resistance with continued current flow. The electromigration-induced stresses are determined from the measured frequency shifts induced in a novel ruby strain sensor embedded immediately beneath the interconnect line on a sapphire substrate. The transparency of the sapphire substrate also facilitated the observation of a hitherto unreported form of dielectric cracking, namely cracking from the interconnect along internal interfaces. The observations of dielectric cracking are in agreement with a recent fracture mechanics model. Analysis of the stress data, together with the results of finite element calculations of the strain energy release rate for crack extension, gives a quantitative estimate of the effective valence Z*(=1.3±0.2) for aluminum.

The disposal of nuclear waste in space

NASA Technical Reports Server (NTRS)

Burns, R. E.

1978-01-01

The important problem of disposal of nuclear waste in space is addressed. A prior study proposed carrying only actinide wastes to space, but the present study assumes that all actinides and all fission products are to be carried to space. It is shown that nuclear waste in the calcine (oxide) form can be packaged in a container designed to provide thermal control, radiation shielding, mechanical containment, and an abort reentry thermal protection system. This package can be transported to orbit via the Space Shuttle. A second Space Shuttle delivers an oxygen-hydrogen orbit transfer vehicle to a rendezvous compatible orbit and the mated OTV and waste package are sent to the preferred destination. Preferred locations are either a lunar crater or a solar orbit. Shuttle traffic densities (which vary in time) are given and the safety of space disposal of wastes discussed.

A new model for predicting moisture uptake by packaged solid pharmaceuticals.

PubMed

Chen, Y; Li, Y

2003-04-14

A novel mathematical model has been developed for predicting moisture uptake by packaged solid pharmaceutical products during storage. High density polyethylene (HDPE) bottles containing the tablet products of two new chemical entities and desiccants are investigated. Permeability of the bottles is determined at different temperatures using steady-state data. Moisture sorption isotherms of the two model drug products and desiccants at the same temperatures are determined and expressed in polynomial equations. The isotherms are used for modeling the time-humidity profile in the container, which enables the prediction of the moisture content of individual component during storage. Predicted moisture contents agree well with real time stability data. The current model could serve as a guide during packaging selection for moisture protection, so as to reduce the cost and cycle time of screening study.

Extended Lagrangian Density Functional Tight-Binding Molecular Dynamics for Molecules and Solids.

PubMed

Aradi, Bálint; Niklasson, Anders M N; Frauenheim, Thomas

2015-07-14

A computationally fast quantum mechanical molecular dynamics scheme using an extended Lagrangian density functional tight-binding formulation has been developed and implemented in the DFTB+ electronic structure program package for simulations of solids and molecular systems. The scheme combines the computational speed of self-consistent density functional tight-binding theory with the efficiency and long-term accuracy of extended Lagrangian Born-Oppenheimer molecular dynamics. For systems without self-consistent charge instabilities, only a single diagonalization or construction of the single-particle density matrix is required in each time step. The molecular dynamics simulation scheme can be applied to a broad range of problems in materials science, chemistry, and biology.

A computational framework for automation of point defect calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goyal, Anuj; Gorai, Prashun; Peng, Haowei

We have developed a complete and rigorously validated open-source Python framework to automate point defect calculations using density functional theory. Furthermore, the framework provides an effective and efficient method for defect structure generation, and creation of simple yet customizable workflows to analyze defect calculations. This package provides the capability to compute widely-accepted correction schemes to overcome finite-size effects, including (1) potential alignment, (2) image-charge correction, and (3) band filling correction to shallow defects. Using Si, ZnO and In2O3 as test examples, we demonstrate the package capabilities and validate the methodology.

A computational framework for automation of point defect calculations

DOE PAGES

Goyal, Anuj; Gorai, Prashun; Peng, Haowei; ...

2017-01-13

We have developed a complete and rigorously validated open-source Python framework to automate point defect calculations using density functional theory. Furthermore, the framework provides an effective and efficient method for defect structure generation, and creation of simple yet customizable workflows to analyze defect calculations. This package provides the capability to compute widely-accepted correction schemes to overcome finite-size effects, including (1) potential alignment, (2) image-charge correction, and (3) band filling correction to shallow defects. Using Si, ZnO and In2O3 as test examples, we demonstrate the package capabilities and validate the methodology.

Materials for high-density electronic packaging and interconnection

NASA Technical Reports Server (NTRS)

1990-01-01

Electronic packaging and interconnections are the elements that today limit the ultimate performance of advanced electronic systems. Materials in use today and those becoming available are critically examined to ascertain what actions are needed for U.S. industry to compete favorably in the world market for advanced electronics. Materials and processes are discussed in terms of the final properties achievable and systems design compatibility. Weak points in the domestic industrial capability, including technical, industrial philosophy, and political, are identified. Recommendations are presented for actions that could help U.S. industry regain its former leadership position in advanced semiconductor systems production.

Design automation for complex CMOS/SOS LSI hybrid substrates

NASA Technical Reports Server (NTRS)

Ramondetta, P. W.; Smiley, J. W.

1976-01-01

A design automated approach used to develop thick-film hybrid packages is described. The hybrid packages produced combine thick-film and silicon on sapphire (SOS) laser surface interaction technologies to bring the on-chip performance level of SOS to the subsystem level. Packing densities are improved by a factor of eight over ceramic dual in-line packing; interchip wiring capacitance is low. Due to significant time savings, the design automated approach presented can be expected to yield a 3:1 reduction in cost over the use of manual methods for the initial design of a hybrid.

Agony of the ecstasy: report of five cases of MDMA smuggling.

PubMed

Low, V H S; Dillon, E K

2005-10-01

The international smuggling of illicit drugs by the ingestion or rectal insertion of drug-filled packages is recognized in the trafficking of heroin and cocaine. Customs authorities, with suspicion of such activities, presented five subjects. The legally allowed radiological examination comprising one supine abdominal radiograph was performed. Radiographic findings demonstrated the presence of multiple enteric oval, capsule-shaped packages of soft tissue density. This was confirmed following supervised evacuation of bowel contents induced by the administration of laxatives. Analysis of the concealed material identified ecstasy (methylenedioxymethamphetamine (MDMA)), a substance not previously reported as transported by this route.

Twenty-Five Years of Dynamic Growth.

ERIC Educational Resources Information Center

Pipes, Lana

1980-01-01

Discusses developments in instructional technology in the past 25 years in the areas of audio, video, micro-electronics, social evolution, the space race, and living with rapidly changing technology. (CMV)

A Course in Polymer Processing.

ERIC Educational Resources Information Center

Soong, David S.

1985-01-01

A special-topics course in polymer processing has acquired regular course status. Course goals, content (including such new topics as polymer applications in microelectronics), and selected term projects are described. (JN)

Self-healable electrically conducting wires for wearable microelectronics.

PubMed

Sun, Hao; You, Xiao; Jiang, Yishu; Guan, Guozhen; Fang, Xin; Deng, Jue; Chen, Peining; Luo, Yongfeng; Peng, Huisheng

2014-09-01

Electrically conducting wires play a critical role in the advancement of modern electronics and in particular are an important key to the development of next-generation wearable microelectronics. However, the thin conducting wires can easily break during use, and the whole device fails to function as a result. Herein, a new family of high-performance conducting wires that can self-heal after breaking has been developed by wrapping sheets of aligned carbon nanotubes around polymer fibers. The aligned carbon nanotubes offer an effective strategy for the self-healing of the electric conductivity, whereas the polymer fiber recovers its mechanical strength. A self-healable wire-shaped supercapacitor fabricated from a wire electrode of this type maintained a high capacitance after breaking and self-healing. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.