Measurement of IC Molding Compound Adhesion Strength and Prediction of Interface Delamination Within Package.

Abstract

The adhesion strength evaluation of molding compounds is a critical issue in structural design and material selection of IC plastic packages, because interface delamination is a main cause of package failure. We previously proposed a method that measures true adhesion strength without the effect of residual stress. This paper describes the dependence of true adhesion strength on adherend materials, temperature and molding compound moisture content as determined by this method. We have also tried to predict interface delamination within a package by comparing the measured strengths with thermal stress analysis results. The results suggest that interface delamination during soldering is caused by thermal stress and decrease in true adhesion strength caused by absorbed moisture rather than vapor pressure.