Thermal Stress Analysis of a PQFP Moulding Process: Comparison of Viscoelastic and Elastic Models

摘要

Numerical models are developed to evaluate the thermal residual stresses arising from the differential thermal expansion between the plastic package constituents. A parametric study is performed using linear-elastic and viscoelastic properties for the encapsulant material. The comparison with experimental stress chip measurements suggests that the model calculated based on the viscoelastic encapsulant predicts the stress profiles more accurately than the linear-elastic counterpart.