Analysis and optimization of torsional stress in the solder joint of plate circuit module

The finite element analysis model of board-level circuit module solder joints is established, and the torsional load is applied to the stress simulation analysis. It is found that the maximum stress point of the board-level circuit appears on the QFP solder joint. The QFP solder joint is the research object, and the height, length and thickness of the QFP solder joint are the design variables. Taking the stress value of QFP solder joint under torsion load as the target value, 17 sets of solder joint models with different levels of combination were designed by response surface method and the corresponding solder joint stress value was obtained. A regression equation was established using the relationship between solder joint stress and structural parameters. Combined with genetic algorithm, the structural parameters of solder joints were optimized. The results show that the optimal combination of the structural parameters of the solder joints is: solder joint height 0.14mm, solder joint length 0.725mm and solder joint width 0.18mm; the simulation verification of the optimal solder joint shows that the maximum stress has dropped by 2.3MPa.