Simulation of warpage considering both thermal and cure induced shrinkage during molding in IC packaging

Warpage is an important issue for IC packages after molding. Due to laminated structure of IC packages, significant warpage occurs owing to differences in shrinkage among constituent materials. Thermal shrinkage is usually considered as the main cause for warpage in an IC. However, cure induced warpage is also important during molding. Analysis without considering cure induced shrinkage can not be accurate. This paper used the P-V-T-C relation and CTE of an encapsulation material to predict the amount of warpage and experimentally verifying the results. Comparing the simulation and experiment results of an EMC-copper composite shows that warpage predictions with P-V-T-C relation and CTE can better predict the amount of warpage of an IC package after molding. For an EMC-copper composite, the amount of warpage is proportional to the cure pressure and inversely proportional to the mold temperature. Besides the P-V-T-C relation and CTE, elastic modulus is found to play an important roll on the amount of warpage in simulation. With this study, the simulation shows that this approach can well predict the amount of warpage for an EMC composite after molding without too much computation effort.