Use of Modified Accumulated Damage Model to Predict Fatigue Failure Lives of Sn-Ag-Cu-based Solder Joints in Ball-Grid-Array-Type Packages

We have developed a modified accumulated damage model that can be used to predict fatigue failure lives of solder joints in electronic devices. Our model calculates the fatigue failure life of solder on the basis of the damage that accumulates during crack propagation by using a finite element method and corrects for the dependence of element size on the calculated life by using the Hutchinson-Rice-Rosengren singularity theory. We predicted the fatigue lives of conventional and copper-core solder bump joints in ball-grid-array packages in thermal cycling tests. The good agreement between these predictions and experimental results indicates that our model can effectively predict fatigue failure life in solder joints.