基于ANSYS 的多层堆叠模块焊接残余应力分析及选材优化

分析了某多层堆叠模块的焊接残余应力,讨论了各功能层不同选材、焊接顺序对模块残余应力的影响,并给出了优化方案。利用 ANSYS 软件进行有限元分析计算,采用 ANAND 本构模型描述焊锡的黏塑性行为,采用基于接触的多点约束(Multi-point Constraint, MPC)算法实现焊锡层与功能层的跨尺度自由度耦合。计算结果表明,焊接顺序对模块残余应力影响较小,各功能层的选材需要综合考虑模块变形及应力安全裕度。刚度较大的底板层可以同时降低模块变形和高温共烧陶瓷(High Temperature Co-fired Ceramic, HTCC)层应力。热膨胀系数较小的盖板层可以降低 HTCC 层应力,但会增大模块整体变形。底板选用 Al/ SiCp(65%),盖板采用可伐合金,可以得到变形及应力安全裕度均满足要求的方案。

Residual Stress Analysis and Material Adoption Optimization for Multilayer Stacked Module Based on ANSYS

The residual stress of a multilayer stacked module is investigated. The influences of layer material and welding sequence on the residual stress of the module are discussed and the optimization recommendations are given. The ANAND model is adopted to describe the viscoplastic behavior of solder with the help of ANSYS finite element analysis. The multi-scale coupling between the soldering layer and the function layer is realized by the contact-based multi-point constraint (MPC) algorithm. Results show that the welding sequence has little effect on residual stress and the layer material selection should consider both the module deformation and the stress safety factor. The higher stiffness of the base plate layer can reduce both the overall deformation and the stress of the high temperature co-fired ceramic (HTCC) layer. The lower thermal expansion coefficient of the cover plate layer can reduce the stress of the HTCC layer, but the overall deformation increases. By adopting Al/ SiCp(65%) base plate and kovar cover plate, the requirements of module deformation and stress safety factor can be both satisfied.