Fully Cure-Dependent Modelling and Characterization of EMC's with Application to Package Warpage Simulation

Package warpage, interface delamination and thermal fatigue are the major reliability concerns for micro-electronic packages, caused by mismatch in thermal expansion together with residual stress originating from the curing process of the packaging polymers. To investigate the influence of the residual stress- and strain fields on the failure predictions and to optimise the product for reliability, cure-dependent viscoelastic constitutive relations for the applied polymers are required. The present paper gives an overview of recent progress in establishing such relations. A model moulding compound is used for cure dependent characterization and is subsequently used for QFN package moulding. The modelled and the experimentally obtained warpage have been compared