Solder electromigration in Cu/In/Cu flip chip joint system

Electromigration in Cu/In/Cu flip chip joint system has been studied at 398 K with a current of 20 kA/cm2. The void nucleation and growth process was investigated with the experiment and the 3D simulation. In was transported towards the anode and a void nucleated at the highest current density point near the cathode. The void nucleated at the In/Cu11In9 interface and grew along the cathode side. The unique solder bump deformation towards the cathode occurred in the early stage of the electromigration test. The temperature of the solder joint during the electromigration test was measured successfully both by a thermo-couple and by the resistance change of the junction line between two flip chip joints.