Solder interconnects are essential to the reliability of electronic devices. The addition of alloying elements was reported to provide beneficial effects to the microstructure and mechanical reliability of lead-free solder alloys. In this work, the effects of Sb addition on the mechanical behavior of SAC305 solder alloy were investigated. Based on differential thermal analysis, it was observed that melting point of SAC-Sb solder was slightly higher than that of SAC305. The mechanical behavior was studied at different temperatures (25 °C–125 °C) and strain rates ( $1\times 10^{-4}$ – $1\times 10^{-2}\,\,1$ /s) for SAC-Sb and SAC 305 solders as a comparison. From the results, ultimate tensile strength of SAC-Sb (10–72 MPa) was generally higher than that of SAC305 (4.54–61.5 MPa) at the aforementioned test conditions. A linear relation between the UTS and yield strength and temperature was identified for test results of SAC305, but the relation was found to be nonlinear for SAC-Sb solder because of solution strengthening effect of Sb in the Sn matrix. Parameters of Anand model were estimated based on mechanical behavior of SAC-Sb and SAC305 solders. Next, the model was used to evaluate thermal fatigue life of an insulated gate bipolar transistor (IGBT) module with SAC-Sb and SAC305 as chip-to-directed bonding copper (DBC) and DBC-to-baseplate attachment materials by finite element modeling. The increase of maximum inelastic strain in one thermal cycle in SAC-Sb solder joints was lower than that in SAC305 solder joints. This result indicates that SAC-Sb solder can provide a considerably better fatigue life under harsh service conditions.

中文翻译：

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Sn“g”u“b 合金在高温下的机械性能和可靠性


焊接互连对于电子设备的可靠性至关重要。据报道，添加合金元素可以对无铅焊料合金的微观结构和机械可靠性产生有益的影响。在这项工作中，研究了 Sb 添加对 SAC305 焊料合金机械行为的影响。基于差热分析，观察到SAC-Sb焊料的熔点略高于SAC305。研究了不同温度 (25 °C–125 °C) 和应变速率 ( $1\times 10^{-4}$ – $1\times 10^{-2}\,\,1$ /s) 下的机械行为对于 SAC-Sb 和 SAC 305 焊料作为比较。从结果来看，在上述测试条件下，SAC-Sb的极限拉伸强度（10-72 MPa）普遍高于SAC305（4.54-61.5 MPa）。 SAC305 的测试结果表明，UTS 与屈服强度和温度之间存在线性关系，但由于 Sn 基体中 Sb 的固溶强化效应，该关系对于 SAC-Sb 焊料而言是非线性的。 Anand 模型的参数根据 SAC-Sb 和 SAC305 焊料的机械行为进行估计。接下来，该模型用于通过有限元建模评估以 SAC-Sb 和 SAC305 作为芯片到定向键合铜 (DBC) 和 DBC 到基板附着材料的绝缘栅双极晶体管 (IGBT) 模块的热疲劳寿命。 SAC-Sb焊点在一个热循环中最大非弹性应变的增加量低于SAC305焊点。该结果表明，SAC-Sb 焊料在恶劣的使用条件下可以提供相当长的疲劳寿命。