Current crowding-induced electromigration in SnAg3.0Cu0.5 microbumps

To determine the relevance of current crowding to electromigration in the SnAg3.0Cu0.5 solder bump, a three-dimensional dual bumps simulation model was designed to demonstrate how current crowding can enhance the local atomic flux along the electron flow path. The finding of void formation occurred at the entrance points to the cathode sides and the enhancement of the growth and clustering of the intermetallic compound at the outgoing points of the anode sides along the electron flow path were verified experimentally. The tilting effect is obvious at the anode/chip side. The experimental mean-time-to-failure was observed, and Black’s equation with Joule heating effect were investigated as well.