Stress Analysis and Optimization of POP Stacked Solder Joints Under Power Cyclic Loading

A finite element analysis model of POP stacked solder joints was established, and the stress distribution of POP stacked solder joints under power cyclic loading was analyzed based on the ANAND intrinsic model. The height of the upper solder j oint, the height of the lower solder joint, the thickness of the top PCB, and the thickness of the middle PCB are selected as the structural parameters, and the stress of the solder j oint is taken as the target value. 27 groups of test combinations with different parameter levels are designed, modeled and simulated by Taguchi's test method, and the bi-objective optimization of the stress of the upper solder joint and the stress of the lower solder joint is carried out by the grey correlation method. The results show that both top and bottom solder joint stresses decrease with the increase of top solder joint height and bottom solder joint height, and increase with the increase of top substrate thickness and middle substrate thickness; The optimum combination of structural parameter levels is 0.35 mm for the top solder joint height, 0.28 mm for the bottom solder joint height, 0.1 mm for the top substrate thickness, and 0.3 mm for the middle substrate thickness, the maximum stresses of the optimized upper and lower solder joints decreased by 0.38 MPa and 0.417 MPa, respectively, which realized the optimization of the structural parameters of the solder joints.