Analytical estimate for cure-induced stresses and warpage in flat packages

Abstract

Warpage of flat packages is partly due to chemical shrinkage of the molding compound during cure and partly due to differences in thermal contraction in the subsequent cooling stage. The latter effect is relatively easy to incorporate in numerical simulations but the cure-induced shrinkage effect is not and is therefore often neglected in warpage simulations. Recent validation studies however showed that it is essential that both effects are taken into account.