• Title/Summary/Keyword: Ball-Joint Center

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Effects of PCB Surface Finishes on Mechanical Reliability of Sn-1.2Ag-0.7Cu-0.4In Pb-free Solder Joint (PCB 표면처리에 따른 Sn-1.2Ag-0.7Cu-0.4In 무연솔더 접합부의 기계적 신뢰성에 관한 연구)

  • Kim, Sung-Hyuk;Kim, Jae-Myeong;Yoo, Sehoon;Park, Young-Bae
    • Journal of the Microelectronics and Packaging Society
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    • v.19 no.4
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    • pp.57-64
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    • 2012
  • Ball shear test was performed by test variables such as loading speed and annealing time in order to investigate the effect of surface finishes on the bonding strength of Sn-1.2Ag-0.7Cu-0.4In Pb-free solder. The shear strength increased and the ductility decreased with increasing shear speed. With increasing shear speed, the electroless nickel immersion gold (ENIG) finish showed dominant brittle fracture mode, while organic solderability preservative (OSP) finish showed pad open fracture mode. The shear strength and toughness for both surface finishes decreased with increasing annealing time under the high-speed shear test of 500 mm/s. Typically, the thickness of intermetallic compound increased with increasing annealing time, which means that exposure of brittle fracture became much easier. With increasing annealing time, the both ENIG and OSP finishes exhibited the pad open fracture mode. Overall, ENIG finish showed higher shear strength rather than OSP finish due to its superior barrier stability.