Warpage simulation for encapsulated package during post-mold curing process

In this study the effects of polymerization conversion and chemical aging on the constitutive behavior and dimension change were characterized and modeled for a commercial epoxy molding compound. Numerical finite element models incorporating these physical and thermomechanical models were developed for simulating the warpage evolution of overmolded BGA packages during post-mold curing (PMC) process. The numerical results were compared to experimental Shadow Moire analyses for validating the modeling methodology. From the analyses it was observed that, while the chemical aging of the molding compound contributed little to the total crosslinking reaction during molding and PMC, it has a significant influence on package warpage during and after the PMC process.