An Approximate Numerical Method for the Prediction of Plastic Strain in Layered Structures

A simple and fast approximate numerical method has been developed using the total deformation theory of plasticity and strength of material relationship to predict stress and strain in layered structures that are common in power electronics and other electronics components. As an application example, the method has been used to estimate the fatigue life of wire bonds in IGBT modules. The method has been compared with Finite Element Analysis method and the results show that the predicted trends are similar for a range of design and loading parameters. Therefore, the approximate method can be used for design optimization of layered structures.