Stress Analysis and Optimization of Laminated Solder Joints Under Bending and Torsion Loads

The research object of this paper is the Stacked solder joints, the three-dimensional model of the solder joints is established using ANSYS software, under the bending and torsion composite loading conditions, the stress analysis of the solder joints model; according to the simulation results, the stress distribution law of the whole array as well as the single stacked solder joints is obtained. Three structural parameters are selected: the height of the solder joint, the diameter of the solder ball and the diameter of the pad, each parameter is taken as three levels, and the corresponding combinations are obtained based on the Box-Behnken experimental design according to the values of the influencing factor levels, and the regression equations of the thermal stresses of the stacked solder joints and the structural parameters are established and combined with the genetic algorithms to optimize the structural parameters of the stacked solder joints, and the optimal the height of the solder joint, diameters of the solder ball and the diameter of the pad are 0.60 mm, 0.35 mm and 0.42 mm, respectively.