Electromigration failure analysis of flip-chip solder joint by using void growth simulation and synchrotron radiation X-ray microtomography

Electromigration (EM) failures of flip-chip solder joints due to void growth, resulting from miniaturization of joint structure, have recently been reported. In addition, growth behavior of electromigration voids in solder joints has not been clarified. It is therefore difficult to predict electromigration failure life. A novel method for simulating growth behavior of an electromigration void in a solder joint was developed. This method was applied to predict failure lives of a conventional solder joint and a copper-cored solder joint. According to the simulation results, the failure life of the copper-cored solder joint is more than three times longer than that of the conventional joint. Moreover, failure life of each joint was measured by electromigration test, and the void shape was observed by synchrotron-radiation X-ray microtomography provided at SPring-8. The good agreement between the predicted growth behaviors and the measured and observed behaviors demonstrate the validity of the developed simulation method.