The importance of molding compound chemical shrinkage in the stress and warpage analysis of PQFPs

This paper addresses the use of finite element techniques to predict residual warpage in PQFPs after encapsulation. Experimental measurements of package warpage are used to validate finite element models of the packages. Failure to incorporate mold compound chemical shrinkage into the FE analysis leads to erroneous predictions of package warpage. The warpage sensitivity of different packages to changes in downset is presented. The validated FE package models predict stress levels in packages which are 70% greater than those with TCE shrinkage alone and questions the accuracy of previously simulations which do not include molding compound chemical shrinkage