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Study on Joint of Micro Solder Bump for Application of Flexible Electronics

플렉시블 전자기기 응용을 위한 미세 솔더 범프 접합부에 관한 연구

  • Ko, Yong-Ho (Advanced Welding and Joining Technology Center, KITECH) ;
  • Kim, Min-Su (Advanced Welding and Joining Technology Center, KITECH) ;
  • Kim, Taek-Soo (Dept. of Mechanical Engineering, KAIST) ;
  • Bang, Jung-Hwan (Advanced Welding and Joining Technology Center, KITECH) ;
  • Lee, Chang-Woo (Advanced Welding and Joining Technology Center, KITECH)
  • 고용호 (한국생산기술연구원 용접접합기술센터) ;
  • 김민수 (한국생산기술연구원 용접접합기술센터) ;
  • 김택수 (한국과학기술원 기계공학과) ;
  • 방정환 (한국생산기술연구원 용접접합기술센터) ;
  • 이창우 (한국생산기술연구원 용접접합기술센터)
  • Published : 2013.06.30

Abstract

In electronic industry, the trend of future electronics will be flexible, bendable, wearable electronics. Until now, there is few study on bonding technology and reliability of bonding joint between chip with micro solder bump and flexible substrate. In this study, we investigated joint properties of Si chip with eutectic Sn-58Bi solder bump on Cu pillar bump bonded on flexible substrate finished with ENIG by flip chip process. After flip chip bonding, we observed microstructure of bump joint by SEM and then evaluated properties of bump joint by die shear test, thermal shock test, and bending test. After thermal shock test, we observed that crack initiated between $Cu_6Sn_5IMC$ and Sn-Bi solder and then propagated within Sn-Bi solder and/or interface between IMC and solder. On the other hands, We observed that fracture propated at interface between Ni3Sn4 IMC and solder and/or in solder matrix after bending test.

Acknowledgement

Supported by : 지식경제부

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