Reliability analysis and optimization of BGA solder based on finite element simulation

Abstract

For the reason of reliability improvement of BGA solder, ANSYS is used to establish a BGA solder model that contains information such as size, material, grid, etc. The thermal stress of solder is selected as the optimization objective by the optimization parameters of solder height, solder radial direction, and spacing of solder. Response surface methodology is used to design 17 sets of different level parameters for simulation calculations, and a regression equation between solder joint stress and optimization parameters is established to obtain the parameter combination with the minimum stress of solder. The analysis results show that the corner solder far from the chip are critical solder joint for failure. The optimized solder joint parameters are as follows. The solder height is 0.5 mm, the solder radial is 0.6 mm, and the solder spacing is 1 mm. The optimized solder joint stress value is 30.818 MPa, which reduces the stress by 27.71% compared to before optimization, which achieved the reliability improvement of BGA solder.