Effects of electromigration on resistance changes in eutectic SnBi solder joints

The motivation of this study is tried to explore the relationship between resistance changes and microstructure evolution of eutectic SnBi solder joints under 104 A/cm2 of current density and 50 °C of ambient temperature. A novel type of one-dimensional solder joints was employed to achieve a true uniform distribution of current density, and a real-time data acquisition system was employed to investigate the voltage changes of the eutectic SnBi solder joints during electromigration process. This study suggested that the resistance remained initially due to the interaction between coarsened phase and Joule heating effect, and then increased due to the formation of continuous Bi-rich phase at anode interface, finally remained again due to the phase segregation of Bi- and Sn-rich phases.