81 research outputs found

    BOK-Printed Electronics

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    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

    Introductory Invited Paper CCGA packages for space applications

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    Abstract Commercial-off-the-shelf (COTS) area array packaging technologies in high reliability versions are now being considered for applications, including use in a number of NASA electronic systems being utilized for both the Space Shuttle and Mars Rover missions. Indeed, recently a ceramic package version specifically tailored for high reliability applications was used to provide the processing power required for the Spirit and Opportunity Mars Rovers built by NASA-JPL. Both Rovers successfully completed their 3-months mission requirements and continued exploring the Martian surface for many more moths, providing amazing new information on previous environmental conditions of Mars and strong evidence that water exists on Mars. Understanding process, reliability, and quality assurance (QA) indicators for reliability are important for low risk insertion of these newly available packages in high reliability applications. In a previous investigation, thermal cycle test results for a non-functional daisychained peripheral ceramic column grid array (CCGA) and its plastic ball grid array (PBGA) version, both having 560 I/Os, were gathered and are presented here. Test results included environmental data for three different thermal cycle regimes (À55/125°C, À55/100°C, and À50/75°C). Detailed information on these-especially failure type for assemblies with high and low solder volumes-are presented. The thermal cycle test procedure followed those recommended by IPC-9701 for tin-lead solder joint assemblies. Its revision A covers guideline thermal cycle requirements for Pb-free solder joints. Key points on this specification are also discussed. In a recent investigation a fully populated CCGA with 717 I/Os was considered for assembly reliability evaluation. The functional package is a field-programmable gate array that has much higher processing power than its previous version. This new package is smaller in dimension, has no interposer, and has a thinner column wrapped with copper for reliability improvement. This paper will also present thermal cycle test results for assemblies of this and its plastic package version with 728 I/Os, both of which were exposed to four different cycle regimes. Two of these cycle profiles are specified by IPC-9701A for tin-lead, namely, À55 to 100°C and À55 to 125°C. One is a cycle profile specified by Mil-Std-883, namely, À65/150°C, generally used for ceramic hybrid packages screening and qualification. The last cycle is in the range of À120 to 85°C, a representative of electronic systems directly exposed to the Martian environment without use in a thermal control enclosure. Per IPC-9701A, test vehicles were built using daisy chain packages and were continuously monitored and/ or manually checked for opens at intervals. The effects of many process and assembly variables-including corner staking commonly used for improving resistance to mechanical loading such as drop and vibration loads-were also considered as part of the test matrix. Optical photomicrographs were taken at various thermal cycle intervals to document damage progress and behavior. Representative samples of these are presented along with cross-sectional photomicrographs at higher magnification taken by scanning electron microscopy (SEM) to determine crack propagation and failure analyses for packages

    MICROELECTRONICS PACKAGING TECHNOLOGY ROADMAPS, ASSEMBLY RELIABILITY, AND PROGNOSTICS

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    This paper reviews the industry roadmaps on commercial-off-the shelf (COTS) microelectronics packaging technologies covering the current trends toward further reducing size and increasing functionality. Due tothe breadth of work being performed in this field, this paper presents only a number of key packaging technologies. The topics for each category were down-selected by reviewing reports of industry roadmaps including the International Technology Roadmap for Semiconductor (ITRS) and by surveying publications of the International Electronics Manufacturing Initiative (iNEMI) and the roadmap of association connecting electronics industry (IPC). The paper also summarizes the findings of numerous articles and websites that allotted to the emerging and trends in microelectronics packaging technologies. A brief discussion was presented on packaging hierarchy from die to package and to system levels. Key elements of reliability for packaging assemblies were presented followed by reliabilty definition from a probablistic failure perspective. An example was present for showing conventional reliability approach using Monte Carlo simulation results for a number of plastic ball grid array (PBGA). The simulation results were compared to experimental thermal cycle test data. Prognostic health monitoring (PHM) methods, a growing field for microelectronics packaging technologies, were briefly discussed. The artificial neural network (ANN), a data-driven PHM, was discussed in details. Finally, it presented inter- and extra-polations using ANN simulation for thermal cycle test data of PBGA and ceramic BGA (CBGA) assemblies

    Enabling More than Moore: Accelerated Reliability Testing and Risk Analysis for Advanced Electronics Packaging

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    For five decades, the semiconductor industry has distinguished itself by the rapid pace of improvement in miniaturization of electronics products-Moore's Law. Now, scaling hits a brick wall, a paradigm shift. The industry roadmaps recognized the scaling limitation and project that packaging technologies will meet further miniaturization needs or ak.a "More than Moore". This paper presents packaging technology trends and accelerated reliability testing methods currently being practiced. Then, it presents industry status on key advanced electronic packages, factors affecting accelerated solder joint reliability of area array packages, and IPC/JEDEC/Mil specifications for characterizations of assemblies under accelerated thermal and mechanical loading. Finally, it presents an examples demonstrating how Accelerated Testing and Analysis have been effectively employed in the development of complex spacecraft thereby reducing risk. Quantitative assessments necessarily involve the mathematics of probability and statistics. In addition, accelerated tests need to be designed which consider the desired risk posture and schedule for particular project. Such assessments relieve risks without imposing additional costs. and constraints that are not value added for a particular mission. Furthermore, in the course of development of complex systems, variances and defects will inevitably present themselves and require a decision concerning their disposition, necessitating quantitative assessments. In summary, this paper presents a comprehensive view point, from technology to systems, including the benefits and impact of accelerated testing in offsetting risk

    Book of Knowledge (BOK) for NASA Electronic Packaging Roadmap

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    The objective of this document is to update the NASA roadmap on packaging technologies (initially released in 2007) and to present the current trends toward further reducing size and increasing functionality. Due to the breadth of work being performed in the area of microelectronics packaging, this report presents only a number of key packaging technologies detailed in three industry roadmaps for conventional microelectronics and a more recently introduced roadmap for organic and printed electronics applications. The topics for each category were down-selected by reviewing the 2012 reports of the International Technology Roadmap for Semiconductor (ITRS), the 2013 roadmap reports of the International Electronics Manufacturing Initiative (iNEMI), the 2013 roadmap of association connecting electronics industry (IPC), the Organic Printed Electronics Association (OE-A). The report also summarizes the results of numerous articles and websites specifically discussing the trends in microelectronics packaging technologies

    Reliability of CGA/LGA/HDI Package Board/Assembly (Revision A)

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    This follow-up report presents reliability test results conducted by thermal cycling of five CGA assemblies evaluated under two extreme cycle profiles, representative of use for high-reliability applications. The thermal cycles ranged from a low temperature of 55 C to maximum temperatures of either 100 C or 125 C with slow ramp-up rate (3 C/min) and dwell times of about 15 minutes at the two extremes. Optical photomicrographs that illustrate key inspection findings of up to 200 thermal cycles are presented. Other information presented include an evaluation of the integrity of capacitors on CGA substrate after thermal cycling as well as process evaluation for direct assembly of an LGA onto PCB. The qualification guidelines, which are based on the test results for CGA/LGA/HDI packages and board assemblies, will facilitate NASA projects' use of very dense and newly available FPGA area array packages with known reliably and mitigation risks, allowing greater processing power in a smaller board footprint and lower system weight

    CHEM-Based Self-Deploying Spacecraft Radar Antennas

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    A document proposes self-deploying spacecraft radar antennas based on cold hibernated elastic memory (CHEM) structures. Described in a number of prior NASA Tech Briefs articles, the CHEM concept is one of utilizing open-cell shape-memory-polymer (SMP) foams to make lightweight structures that can be compressed for storage and can later be expanded, then rigidified for use. A CHEM-based antenna according to the proposal would comprise three layers of microstrip patches and transmission lines interspersed with two flat layers of SMP foam, which would serve as both dielectric spacers and as means of deployment. The SMP foam layers would be fabricated at full size at a temperature below the SMP glass-transition temperature (Tg). The layers would be assembled into a unitary structure, which, at temperature above Tg, would be compacted to much smaller thickness, then rolled up for storage. Next, the structure would be cooled to below Tg and kept there during launch. Upon reaching the assigned position in outer space, the structure would be heated above Tg to make it rebound to its original size and shape. The structure as thus deployed would then be rigidified by natural cooling to below T

    Assessment of genetic diversity in late flowering almond varieties using ISSR molecular markers aimed to select genotypes tolerant to early spring frost in Yazd province

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    The genetic diversity of 19 late flowering almond genotypes in Yazd province were assessed using ISSR markers. 10 selected ISSR primers revealed 101 polymorphic bands among which the 5`-G(AG)7ASG-3` with 17 and 5`-A(GA)7GSC-3` with 3 bands had the most and the least polymorphic bands respectively. In principal component analysis the explanation of a minor part of the total diversity by few prior components as well as the distribution of total variance among different components, indicate the relevant scattering of the ISSR primers through the genome and the validity of ISSR data for the genetic analysis in almond germplasm. The most genetic similarity in cluster analysis was observed between the genotypes 88 and 191. The high genetic similarity between some genotypes may be caused by their common origin or the geographical similarity between their regions of cultivation and improvement. The transfer and translocation of these genotypes among different studied regions have been carried out frequently. The results of molecular analysis showed that almond varieties and genotypes that are collected from close geographical regions all over the Yazd province are of large genetic homogeneity and the overall polymorphism content in studied genomes is rather low. Considering the self-incompatible nature of the almond plants, it may be concluded that the domesticated genotypes and those cultivated in studied regions, have had little mixture with alien almond germplas

    Extending Alkenes’ Value Chain to Functionalized Polyolefins

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    Naphtha is one of the crude oil distillation products, bringing almost the lowest value-addition to crude oil, compared to other refinery products such as liquid petroleum gas, gasoline, and diesel. However, Naphtha can be converted to one of the highest value products at the end of the value chain, i.e., polyolefins. Although the production of conventional commodity polyolefins from crude oil, is considered as one of the final products in alkenes’ value chain, there are specialty polyolefins with higher values. Specialty polyolefins are small volume, high-performance thermoplastics with high-profit margins compared to traditional commodity polyolefins. Recently, some special purpose functionalized polyolefins have been developed as efficient substituents for high-performance engineering thermoplastics. Polyolefins are exploited as cost-effective platforms to produce these functionalized thermoplastics. They are promising candidates for replacing high-performance polymers with high-cost raw materials and elaborate production processes. So, functional polyolefins have introduced a new paradigm in the production of high-performance thermoplastics, extending the alkenes’ value chain and increasing profitability. High-performance specialty polyolefins may find exceptional markets in niche applications. In this chapter, the commercial specialty and functional polyolefins’ current situation and prospects are reviewed

    Detection of tetracycline resistance genes, aminoglycoside modifying enzymes, and coagulase gene typing of clinical isolates of Staphylococcus aureus in the Southwest of Iran

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    Objective(s): The aim of the present study was to determine the aminoglycoside modifying enzymes (AMEs) encoded genes, tetracycline resistance genes, and the coa based typing of Staphylococcus aureus isolates in the Southwest of Iran. Materials and Methods: Antimicrobial susceptibility of isolates was carried out by agar disk diffusion methods. Two sets of multiplex PCR mixture were used for detection of AME genes and tet genes.  All of the isolates were typed with the coagulase gene typing method. Of the 121 isolates, 29.75% and 47.93% were resistant to at least one aminoglycosides and tetracyclines, respectively. Results: The aac(6')-Ie-aph(2'') was the most frequent gene (97.22%), and aph (3')-IIIa and ant (4')-Ia genes were detected in 61.11% and 11.11% of aminoglycoside resistant isolates, respectively. The tetK and tetM genes were detected in 82.75% and 56.9% of tetracycline resistant isolates, respectively. Overall 31.4% of isolates were MRSA. Totally 17 distinct coa gene RFLP patterns, numbered C1 to C17, were observed.  The C5 was the most frequent coa type with 31 isolates. Conclusion: The aac(6')-Ie-aph(2'') and aph (3')-IIIa genes were the most important genes contributing to aminoglycosides resistance, while resistance to tetracyclines was mediated by tetK and tetM genes. Interestingly all S. aureus with C5 as the most prevalent coa-type were resistant to at least one of the aminoglycoside antibiotics and tetracycline simultaneously. Moreover, 30 out of 31 isolates with this coa type were MRSA, indicating the importance of the C5 coa-type in MRSA strains and also in isolates that were resistant to aminoglycosides and tetracycline
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