Thermal Aging Behavior of Fine Pitch Palladium Coated Silver (PCS) Ball Bonds on Al Metallization

The high price of Au has motivated many to look for alternative bonding wire materials in the field of microelectronics packaging. In the present study, the reliability performance of palladium coated silver (PCS) wire in high temperature storage test (HTST) is carried out using 18 μm diameter fine pitch PCS wire. Fine pitch ball bonds are made on Al metallization, with bonded ball diameter (BBD) of 32 ± 0.5 μm and ball height (BH) of 8 ± 0.5 μm. The aging temperature used in HTST is 170 °C and both shear and pull test are used to evaluate the aged ball bonds at regular time intervals. The shear force increases from 9.9 gf at 96 h to 12.5 gf at 192 h, and remains almost constant until 1344 h, and starts dropping gradually until 10.9 gf at 1848 h. The pad lift percentage recorded in pull test gradually drops from 90 % at 96 h to 20 % at 1008 h, and increases to 90 % at 1848 h. The chip side fractography after shear test indicates that the main failure modes are through pad at 96 h, through ball bond at 504 h, and half of both at 168 h, respectively. Cross-sectional images show that the thickness of the intermetallic compound (IMC) layer growth follows parabolic relationship and the rate constant is 0.10 ± 0.02 μm/h½. Gaps are observed along the periphery of the ball bond interface where no IMC is observed. The IMCs are located at the center of the ball bond interface, and the width is 16.0–19.3 μm at 96 h and 17.2–22.7 μm at 1344 h, respectively

Index to 1981 NASA Tech Briefs, volume 6, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1981 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Index to 1983 NASA Tech Briefs, volume 8, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1983 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Parts, Materials, and Processes Experience Summary

The ALERT program, a system for communicating common problems with parts, materials, and processes, is condensed and catalogued. Expanded information on selected topics is provided by relating the problem area (failure) to the cause, the investigations and findings, the suggestions for avoidance (inspections, screening tests, proper part applications), and failure analysis procedures. The basic objective of ALERT is the avoidance of the recurrence of parts, materials, and processed problems, thus improving the reliability of equipment produced for and used by the government

Integration of optical interconnections and optoelectronic components in flexible substrates

Licht als informatiedrager voor datacommunicatie kende een ongezien succes in de laatste decennia. Wegens de lage verliezen en hoge datasnelheden hebben ze voor het overbruggen van lange afstanden hun elektrische tegenhangers reeds geruime tijd verdrongen. Deze trend zet zich ook voort voor korte afstand communicatie op printplaten. Naast zijn functie als informatiedrager, wordt licht ook gebruikt om een waaier aan fysische grootheden te meten. Ook hier heeft licht enkele significante voordelen t.o.v elektrische informatiedragers, waardoor optische sensoren wijdverspreid zijn. Een tweede duidelijke trend binnen de elektronica is het gebruik van flexibele printkaarten. Deze zijn veel dunner, lichter en betrouwbaarder dan de klassieke harde printkaarten, waardoor ze uiterst geschikt zijn voor draagbare toepassingen waar compactheid en een laag gewicht hoge vereisten zijn. De flexibiliteit van de printplaten laat ook toe hen te gebruiken op onvlakke oppervlakken en op bewegende onderdelen. Het doel van het gepresenteerde doctoraatswerk is de ontwikkeling van een nieuw technologieplatform dat bovengenoemde trends combineert. Alle bouwblokken van optische communicatie, gaande van actieve opto-elektronische componenten, aanstuurelektronica, golfgeleiderbaantjes en galvanische verbindingen tot optische koppelstructuren tussen de verschillende bouwblokken, worden zodanig gerealiseerd dat elke component flexibel is en geïntegreerd wordt in een dunne folie met een dikte van slechts 150µm. Op die manier bekomen we een flexibele folie met alle passieve en actieve onderdelen voor optische communicatie geïntegreerd met enkel een elektrische interface naar de buitenwereld, wat de aanvaarding en toepassing van deze technologie in de huidige elektronica aanzienlijk kan versnellen. Binnen het doctoraatswerk werden alle voorgestelde technologieën en processen gerealiseerd en geoptimaliseerd. Bovendien werden de optische verliezen, warmteaspecten, hoogfrequent gedrag, mechanisch gedrag en betrouwbaarheid van de technologie gekarakteriseerd en vergeleken met de huidige state-of-the-art

Advance in Energy Harvesters/Nanogenerators and Self-Powered Sensors

This reprint is a collection of the Special Issue "Advance in Energy Harvesters/Nanogenerators and Self-Powered Sensors" published in Nanomaterials, which includes one editorial, six novel research articles and four review articles, showcasing the very recent advances in energy-harvesting and self-powered sensing technologies. With its broad coverage of innovations in transducing/sensing mechanisms, material and structural designs, system integration and applications, as well as the timely reviews of the progress in energy harvesting and self-powered sensing technologies, this reprint could give readers an excellent overview of the challenges, opportunities, advancements and development trends of this rapidly evolving field

Synthesis, Chracterization and Applications of Coated Composite Materials for Energy Applications

The formulation of coated composite materials is an important field of research around the world today. Coated composite materials include inhomogeneous and anisotropic materials. These materials are formulated by an amalgamate minimum of two or more materials that accommodate different properties. These materials have a vast field of appealing applications that encourage scientists to work on them. Due to their unique properties, such as their strength, liability, swiftness, and low cost, they are used as promising candidates for reliable applications in various fields, such as biomedical, engineering, energy devices, wastewater treatment, and agriculture. Different types of composite materials have had a noticeable impact in these fields already, such as glass, plastic, and, most promisingly, metal oxide nanoparticles

NASA patent abstracts bibliography. A continuing bibliography (supplement 22). Section 1: Abstracts

Abstracts are cited for 234 patents and patent applications introduced into the NASA scientific and technical information system during the period July 1982 through December 1982. Each entry consists of a citation, an abstract, and in most cases, a key illustration selected from the patent or patent application

NASA Tech Briefs, Fall/Winter 1981

Topics covered: NASA TU Services: Technology Utilization services that can assist you in learning about and applying NASA technology; New Product Ideas: A summary of selected innovations of value to manufacturers for the development of new products; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences