Clean Technology (청정기술)

The Korean Society of Clean Technology (한국청정기술학회)
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Prevention of Running Blots between the Patterns during the Electroless Nickel Electroless Palladium Immersion Gold (ENEPIG) Surface Finish

무전해 니켈·팔라듐·금도금 표면처리 공정의 도금 번짐 불량 및 개선

  • Eom, Ki Heon (Department of Chemical Engineering, Pukyong National University) ;
  • Seo, Jung-Wook (Manufacturing & Engineering Center, Samsung Electro-Mechanics Co., Ltd.) ;
  • Won, Yong Sun (Department of Chemical Engineering, Pukyong National University)
  • 엄기헌 (부경대학교 화학공학과) ;
  • 서정욱 (삼성전기주식회사 생산기술센터) ;
  • 원용선 (부경대학교 화학공학과)
  • Received : 2013.03.15
  • Accepted : 2013.03.28
  • Published : 2013.06.28
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Abstract

The running blots between patterns during electroless nickel electroless palladium immersion gold (ENEPIG) surface finish of printed circuit board (PCB) are investigated and a proper solution is presented. Computational chemistry is first employed to understand the process and experiments are then designed to verify the proposed ideas. A $PdCl_2$ activator which has relatively weak chemical bonding to the epoxy resin is introduced to prevent the formation of palladium seeds on the epoxy resin and a couple of operational measures such as increasing HCl concentration and lowering the temperature of Pd activation process are executed to prevent a further hydrolysis of $PdCl_2$ to more stable $Pd(OH)_2$ in aqueous solution. Computational chemistry provides thermodynamic backgrounds for experiments and their results. This combined approach is expected to be very useful in the research of relevant processes.

무전해 니켈 팔라듐 금 표면처리 공정의 도금 번짐 불량의 근본적인 원인을 이해하고 이를 해결하기 위한 방법을 제시하였다. 이에 계산화학을 이용하여 공정을 정성적으로 설명하고 이를 바탕으로 가정을 검증하기 위한 실험을 계획하였다. 도금 번짐으로 발전되는 고분자 레진 위의 팔라듐 시드의 핵 생성을 막는 것에 초점을 맞추어 고분자 레진과 화학적으로 결합력이 약한 $PdCl_2$ 팔라듐 촉매를 도입하였으며 이 촉매가 수용액 중에서 추가적인 가수분해 반응으로 더 안정한 $Pd(OH)_2$를 형성함으로써 고분자 레진 위에 팔라듐 시드의 원천으로 작용하지 않도록 염산(HCl)의 농도를 높이거나 팔라듐 활성화 공정의 온도를 낮추어 보았다. 계산화학은 매 단계 실험의 이론적인 근거를 제시해 주었으며 실험 결과를 해석하는 데 큰 도움을 주었다. 이와 같이 실험과 이론을 접목시킨 본 연구의 접근법은 관련 공정에서 매우 유용하게 활용될 수 있을 것으로 기대된다.

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References

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