Electromigration behavior of the Cu/Au/SnAgCu/Cu solder combination

Abstract

The electromigration behavior of the Cu/Au/SnAgCu/Cu combination was investigated under 103 A/cm2 of current stressing at ambient temperature. The Au layer, when it acts as a cathode, was consumed continuously, and no significant compound was found at the interface. Meanwhile, Cu6Sn5 was formed at the anodic Cu layer, and the thickness of the compound increased with increasing time. The Au atoms were found to be trapped in Cu6Sn5 within the solder matrix. The AuSn4 compound precipitated while attaching to Cu6Sn5 at the Cu6Sn5/solder interface. The thermomigration effect was found to be insignificant in this work as no obvious reaction occurred at the cathode/anode sides or in the solder matrix without current stressing.