Thermal Warpage Behavior Analysis of Semiconductor Packages

Prediction of warpage behaviors of semiconductor packages is the most fundamental work for their reliability design. Thus, it is also essential to simulate the fracture of the packages. In this paper, three different test samples were prepared to predict the warpages from the assembly process and material properties by finite element method. From the comparison between experimental study and numerical calculation, it seemed that the initial warpage of the samples was close to zero during the molding process of epoxy-mold-compound (EMC) due to the pressing of a metal mold onto the warping samples. Thus, the warpage of the samples after the molding process could be roughly predicted by using the stress free temperature of EMC defined as the molding temperature in this paper. Furthermore, we found that the calculation including the contribution of the chemical shrinkage of EMC was more effective to simulate the warpages.