Homogenization schemes for TSV interposer packages

In 3D through-silicon-via (TSV) interposer package, there are large numbers of micro bumps and micro solder balls, the sizes of the entities in the package having a difference of 3 orders of magnitude. This multi-scale structure brings difficulties to establish the finite element model for analyzing the thermal fatigue life of board-level solder joint. Homogenization method is adopted to avoid these difficulties in this work. The micro bump/underfill layer between the chip and TSV interposer is replaced by the homogenous material layer with equivalent material parameters determined by homogenization method. Four different homogenization schemes are proposed to investigate the thermal fatigue life of the board-level solder joint, and their results are compared. It suggests that the micro bump/underfill layer between the chip and TS V interposer can be replaced by the corresponding underfill material layer in the finite element analysis of solder joint fatigue life.