Abstract A Cu-cored solder ball (CCSB) is often used as the interconnection material for 3D package. The CCSB has a Cu core surrounded by Sn-Ag-Cu alloy. The effect of the Cu core on mechanical reliability of the CCSB was investigated using thermal shock test. Microstructure and thermal shock reliability of the CCSB with organic solderability preservative (OSP) surface finish was compared with that of Sn-3.0wt.%Ag-0.5wt.%Cu (SAC) solder. The thermal shock test was performed in the temperature range of −40 °C to 125 °C in compliance with JESD22-A104. Failure mechanism was analyzed by finite element method analysis. Average number of thermal shock cycles for the CCSB/OSP joints was 1.15 times higher than that for SAC/OSP joints. Maximum value of simulated plastic strain for the SAC/OSP joints was 1.25 times higher than that for the CCSB/OSP joints because the stand-off height of the CCSB/OSP joints could be maintained by the Cu core.

中文翻译：

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倒装芯片封装中铜芯焊球热冲击试验的机械可靠性

摘要 铜芯焊球（CCSB）常被用作3D封装的互连材料。CCSB 有一个被 Sn-Ag-Cu 合金包围的铜芯。使用热冲击试验研究了铜芯对 CCSB 机械可靠性的影响。将具有有机可焊性防腐剂 (OSP) 表面光洁度的 CCSB 的微观结构和热冲击可靠性与 Sn-3.0wt.%Ag-0.5wt.%Cu (SAC) 焊料进行了比较。热冲击测试在 -40 °C 至 125 °C 的温度范围内进行，符合 JESD22-A104。失效机理采用有限元法分析。CCSB/OSP 接头的平均热冲击循环次数是 SAC/OSP 接头的 1.15 倍。SAC/OSP 接头的模拟塑性应变最大值为 1。