Phase field modelling of the electromigration behaviour in sintered silver

Silver sintering has been a promising interconnect technique for high temperature electronics, but the electromigration behaviour of the achieved interconnect structure in service are yet to be fully understood. In this study, a phase field model is developed to study the electromigration behaviour of sintered silver with emphasizing on the migration kinetics of pores and morphology evolution of silver nanoparticles. Results show that the dihedral angle and sintering neck length as well as the migration velocity of the pores are larger with higher ratio of surface energy to grain boundary energy (γs/γgb). Under electric current stressing, the pores migrate to the cathode side and coalesce to form a large pore accompanied by the silver grain growth, larger γs/γgb leads to sharper increase of electrical resistance. The developed model and results provide insights to understand the electromigration behaviour and the open-circuit failure of sintered silver interconnects under electric current stressing.Graphical abstract