• Title/Summary/Keyword: conductive anodic filament

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ECM and CAF Failure on PCBs (PCB의 ECM과 CAF 불량)

  • Lee, Jin-Ho
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.61-74
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    • 2014
  • 전자제품에서 반도체 부품의 협피치화가 진행됨에 따라 PCB의 회로와 회로 사이의 간격 혹은 Hole과 Hole간의 간격이 줄어듬에 따라 ECM(Electrochemical Migration)과 CAF(Conductive Anodic Filament)의 불량이 증가하게 되었다. 특히 열악한 환경에서 사용되는 Power Supplier나 사용전압이 높아지는 전기 및 수소연료 자동차 분야에선 이들 불량방지에 노력을 기울여야겠다.

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Effect of Applied Voltage Bias on Electrochemical Migration in Eutectic SnPb Solder Alloy

  • Lee, Shin-Bok;Jung, Ja-Young;Yoo, Young-Ran;Park, Young-Bae;Kim, Young-Sik;Joo, Young-Chang
    • Corrosion Science and Technology
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    • v.6 no.6
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    • pp.282-285
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    • 2007
  • Smaller size and higher integration of electronic systems make narrower interconnect pitch not only in chip-level but also in package-level. Moreover electronic systems are required to operate in harsher conditions, that is, higher current / voltage, elevated temperature / humidity, and complex chemical contaminants. Under these severe circumstances, electronic components respond to applied voltages by electrochemically ionization of metals and conducting filament forms between anode and cathode across a nonmetallic medium. This phenomenon is called as the electrochemical migration. Many kinds of metal (Cu, Ag, SnPb, Sn etc) using in electronic packages are failed by ECM. Eutectic SnPb which is used in various electronic packaging structures, that is, printed circuit boards, plastic-encapsulated packages, organic display panels, and tape chip carriers, chip-on-films etc. And the material for soldering (eutectic SnPb) using in electronic package easily makes insulation failure by ECM. In real PCB system, not only metals but also many chemical species are included. And these chemical species act as resources of contamination. Model test systems were developed to characterize the migration phenomena without contamination effect. The serpentine-shape pattern was developed for analyzing relationship of applied voltage bias and failure lifetime by the temperature / humidity biased(THB) test.

Dominant Migration Element in Electrochemical Migration of Eutectic SnPb Solder Alloy in D. I. Water and NaCl Solutions (증류수 및 NaCl 용액내 SnPb 솔더 합금의 Electrochemical Migration 우세 확산원소 분석)

  • Jung, Ja-Young;Lee, Shin-Bok;Yoo, Young-Ran;Kim, Young-Sik;Joo, Young-Chang;Park, Young-Bae
    • Journal of the Microelectronics and Packaging Society
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    • v.13 no.3 s.40
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    • pp.1-8
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    • 2006
  • Higher density integration and adoption of new materials in advanced electronic package systems result in severe electrochemical reliability issues in microelectronic packaging due to higher electric field under high temperature and humidity conditions. Under these harsh conditions, metal interconnects respond to applied voltages by electrochemical ionization and conductive filament formation, which leads to short-circuit failure of the electronic package. In this work, in-situ water drop test and evaluation of corrosion characteristics for SnPb solder alloys in D.I. water and NaCl solutions were carried out to understand the fundamental electrochemical migration characteristics and to correlate each other. It was revealed that electrochemical migration behavior of SnPb solder alloys was closely related to the corrosion characteristics, and Pb was primarily ionized in both D.I. water and $Cl^{-}$ solutions. The quality of passive film formed at film surface seems to be critical not only for corrosion resistance but also for ECM resistance of solder alloys.

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