Failure modeling of BGA package for reliability evaluation of handheld products under drop event

Abstract

In this paper, the failure modeling of BGA(Ball Grid Array) package is studied to evaluate the drop impact reliability of handheld products. In order to perform explicit full FEA modeling of handheld products, it costs large amount of computing time due to large aspect ratio of element size between solder interconnects and the other structures in a product. However, the conventional simple FEA modeling is too limited to simulate actual behavior of solder joint during impact. Thus, in this study, the effective way to represent solder interconnect for FEA is considered relatively simpler yet detailed. The assembly composed of BGA package and PCB is considered to assess the feasibility of solder ball failure modeling during drop impact loading applied. Especially for the modeling of solder balls, detailed solid model and simple beam model are compared in view of computational efficiency and numerical accuracy. Consequently, board-level drop tests are conducted after preparing various test jigs, which are implemented to apply different loading condition to BGA package. The results shows different drop impact life for solder interconnects depending on the test jig type. In the conclusion, the feasibility of beam model for solder balls is shown by correlating the stress level and drop impact life obtained from the experiments.