Electromigration reliability enhancement of flip chip interconnects using Cu-doped SnPb solder

This work investigates electromigration resistance of three solder bump compositions, i.e. Sn63Pb37, SnPbCu, and SnPbNi. FCBGA with Cu-doped SnPb interconnects are observed to have 3.5-fold improvement in characteristic life (t63) than that of FCBGA using eutectic SnPb solder. On the other hand, significant reliability degradation (55%) is obtained when employing Ni-doped SnPb solder.