Finite element modeling on thermal fatigue of BGA solder joints with multiple voids

The electronics industry strives for miniaturization and diversification of functionality while the demand for reliability of electronic components strongly increases. The manufacturing process induces voids in lead-free solder joints which influence its mechanical behavior and hence the failure resistivity of these interconnections. But even though many investigations have been done in this field, it still remains unsettled whether voids enhance or hinder the joints' reliability. Recent advances include strain experiments and finite-element-analysis for low void quantities. It has been shown that the position and size of voids are the most influential parameters in that matter. In this work a parameterized finite element model is presented and used to analyze the change in stress and strain distributions in the solder joints with different void configurations. Based on the extracted accumulated creep strain per temperature cycle joints with voids are compared to the respective void free state. It will be shown that voids have the potential to heavily reduce the fatigue life of BGA solder joints.