A methodology for predicting failure sites and failure modes in an IC package

A methodology for predicting sites and modes of thermomechanical failure in an IC package is developed. Singular stress fields around several stress c oncentration locations in a typical plastic-encapsulated IC package are cal culated using special variable-order singular boundary elements and the sin gular value decomposition method. The strain energy density distributions a round all the stress concentration locations are then obtained from the sin gular stress fields and compared. The most likely failure site as the tempe rature of the package is raised is then determined as well as the likely mo des of failure, ie interfacial delamination or cracking of mold compound.