Annealing effect to constitutive behavior of Sn-3.0Ag-0.5Cu solder
Annealing effect to constitutive behavior of Sn-3.0Ag-0.5Cu solder
复制标题
退火对Sn～3.0Ag～0.5Cu焊料本构行为的影响
DOI：
10.1007/s10854-018-8705-0
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发表时间：
2018-05-01
影响因子：
2.8
通讯作者：
Yao, Yao
中科院分区：
文献类型：
--
作者：
Long, Xu;Tang, Wenbin;Yao, Yao
在商用电子设备的电子封装结构中，锡-银-铜基焊料合金正在取代锡-铅焊料。为了评估结构的可靠性，焊料的力学性能是数值模拟的关键。研究发现，退火工艺可以稳定锡-37Pb焊料的材料性能。本文研究了退火热处理对锡-3.0Ag-0.5Cu(SAC305)焊料拉伸性能的影响，并与锡-37Pb焊料进行了比较。结果表明，经退火处理后，两种材料的抗拉强度都比较稳定和一致，但退火工艺提高了以位错运动为主的SAC305焊料的塑性，阻止了以晶界滑移机制为主的锡铅焊料的硬化变形。此外，在基于统一蠕变塑性理论的本构模型中，对退火效应进行了量化。在拉伸应变率为1×10~(-4)~1×10~(-3)S(~(-1))的范围内，根据测量的应力-应变关系标定了参数。模型中主要参数的数值回归揭示了SAC305焊料和锡-37Pb焊料在退火热处理过程中的内在差异。
Sn-Ag-Cu based solder alloys are replacing Sn-Pb solders in electronic packaging structures of commercial electric devices. In order to evaluate the structural reliability, the mechanical property of solder material is critical to the numerical simulations. Annealing process has been found to stabilize material properties of Sn-37Pb solder material. In the current study, the annealing effect on tensile behaviour of Sn-3.0Ag-0.5Cu (SAC305) solder material is investigated and compared with Sn-37Pb solder. It is found that the tensile strength for both materials are more stabilized and consistent after the annealing process, nevertheless, the annealing process will improve the plasticity of SAC305 solder dominated by dislocation motion, and impede the occurrence of hardening deformation in Sn-37Pb solder dominated by grain-boundary sliding mechanism. Furthermore, the annealing effect is quantified in the proposed constitutive model based on unified creep-plasticity theory. The parameters are calibrated against the measured stress-strain relationships at the tensile strain rates ranging from 1 x 10(-4) to 1 x 10(-3) s(-1). The numerical regressions for dominant parameters in the proposed model reveal the intrinsic differences between SAC305 and Sn-37Pb solders under annealing treatment.