Stress Analysis Optimization And Prediction Of Stack BGA Solder Joints Under Random Vibration Conditions

Based on ANSYS, a finite element analysis model of the interconnect structure of laminated BGA solder joints was established, and the stress analysis was performed by applying random vibration loads to it. SAC305 was used as the solder joint material and Cu as the solder pad material. Select the solder ball diameter, solder joint height, solder pad diameter, and solder pad height as variables, and the maximum stress of the solder joint structure as the target value, The combination of 16 different factor levels was designed using the orthogonal design method. Through the analysis of variance in the simulation data, the pad height and pad thickness show significant performance on the maximum stress of the solder joint structure. The range analysis of the simulation data yields the optimal combination of parameters,That is, the solder ball diameter is 0.65mm, the solder joint height is 0.50mm, the solder pad diameter is 0.50mm, and the solder pad height is 0.035mm. The maximum stress value of the solder joint structure is 15.7Mpa, which is 0.8Mpa compared with the minimum value of 16.5Mpa for the maximum stress in the 16 sets of data, the optimization effect is realized. Based on the simulation experimental data, SPSS is used for regression analysis, and the maximum stress prediction model of the above factors and the solder joint interconnection structure is obtained, According to the experimental verification of 8 sets of extended level combination policy, the accuracy of the stress prediction model is 96.93%. This reflects the good usability of this stress prediction model.