OS2402 Inelastic Stress Simulation for Micro-bump in 3D SiP

Abstract

In this study, FEM simulation for micro-bump with and without under fill was performed to understand singular stress field around triple junction and effects of under fill resin on its stress field. Micro-bump was constructed by 20 copper grains which had anisotropic crystal orientation. Values of parameter on singular stress field (λ and K) and area size of singular stress field were estimated up to nominal strain of 1 % and it was shown that under fill resin played an important role for singular stress field at triple junction of micro-bump.