Influence of Al/CucorAl wire bonding on reliability of SiC devices

Power semiconductor devices are developing in the direction of miniaturization, high power density and high operating temperature, which puts forward higher requirements for device packaging technology, especially the wire bonding technology which to realize the internal electrical interconnection of devices. Compared with traditional silicon-based semiconductors, the SiC devices have higher requirements for wire bonding reliability due to higher chip junction temperature. In this paper, the influence of aluminum wire and aluminum clad copper wire on the reliability of SiC devices is studied by means of power cycling test and finite element numerical simulation. The experimental results show that the power cycling lifetime of SiC devices bonded with aluminum clad copper wire is 26% higher than that of devices bonded with aluminum wire. The results of finite element simulation show that under the same current load condition, the junction temperature of aluminum clad copper wire bonding device is lower, the current carrying capacity is stronger, and the maximum stress of bonding wire appears at the Al-Cu interface, rather than the bonding wire-chip interface, which leads to longer power cycling lifetime.