Use of modified accumulated damage model to predict fatigue failure-life of Sn-Ag-Cu based solder joints in ball-grid-array-type packages

Abstract

We have developed a modified accumulated damage model that can be used to predict the fatigue lives in solder joints in electronics devices. Our model calculates the fatigue life of solder based on the damage that accumulates during crack propagation using a finite element method and corrects for the influence of element size on the calculated life using Hutchinson-Rice-Rosengren singularity theory. We predicted the fatigue lives of two types of solder joints in Ball-Grid-Array (BGA) packages during thermal cycling tests: one is conventional solder bumps and the other is Cu-cored solder bumps. The predictions agreed well with the experimental results, which indicates that our model can effectively predict fatigue life in solder joints.