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.