Stress Distribution of Stacked Chip Package in Curing Process

In this paper, packaging process for a typical stacked three-chip packaging structure has been studied in detail by finite element analysis (FEA) method. The simulation shows that thermal stress may result in die crack and delamination before package has been finished. During the each curing process, the stresses of joints of die in the bottom layer are largest and the system reliability is not lowered over three layers die. The package would be destroyed most easily in cure II step. Failure rate of upper die is also high in the cure III, as the epoxy molding compound (EMC) can bring residual stress of phase changing, and combining FEA results, the package structure has been optimized