A finite element simulation of PoP assembly processes

Warpage, high stress in dies and solder joints are introduced in assembly process of a package-on-package component. In this paper, a finite element approach is proposed to predict the warpages and stresses during the full assembly process. By the techniques of element die and birth as well as restart method, the approach is able to transfer the stress and warpage in one process to the next so that a full evolution of the stress and warpage during assembly can be obtained. The simulation results show that the approach is feasible and effective, and it can be used to optimize the packaging process.