基于再流焊冷却过程应力分析的板极组件BGA焊点参数优化

建立了板级组件BGA（Ball Grid Array）焊点有限元分析模型，对BGA焊点进行了再流焊冷却过程应力仿真分析，设计并完成了验证性实验以验证仿真分析方法的有效性，分析了焊点结构参数和材料变化对焊点再流焊冷却过程应力应变的影响，采用响应面法建立了焊点应力与结构参数的回归方程，结合遗传算法对焊点结构参数进行了优化.结果表明：实验结果证明了仿真分析的有效性；焊点应力随着焊点高度的增加而增大，随着焊点直径的增加而减小；最优焊点结构参数水平组合为：焊点高度0.44mm、焊点直径0.65mm、焊盘直径0.52mm和焊点间距1.10mm；对该最优焊点仿真验证表明最大应力下降了0.1101MPa.

Parameter Optimization of the Board Level Assembly BGA Solder Joints Based on Stress Analysis of Reflow Cooling Process

A finite element model of board level assembly BGA(Ball Grid Array) solder joint is established,the stress simulation analysis of BGA solder joint in the cooling process of reflow soldering is carried out,the confirmatory experiment is designed and carried out to verify the validity of simulation analysis method,and the influence of solder joint structure parameters and material on the stress and strain of solder joint are analyzed.The regression equations of the stress and structure parameters of the solder joints is established by the response surface method,and solder joint structure parameters are optimized by genetic algorithm.The results show that the experiment results verify the effectiveness of the simulation analysis,the stress of the solder joint increases with the increase of the height of the solder joint,and decreases with the increase of the diameter of the solder joint,and the optimal level combination of solder joint structure parameters is the height of 0.44mm,the diameter of 0.65mm,the pad diameter of 0.52mm and the solder joint pitch of 1.10mm,the simulation results of the optimal level combination of solder joint show that the maximum stress decreases by 0.1101MPa.