Abstract
Copper wires are increasingly used to replace gold wires for providing bonding between Insulated gate bipolar transistor (IGBT) modules, due to their better electrical properties and lower cost. However, not many studies have been conducted to study the electromigration induced failure of copper wedge bonding used in the IGBT module. In this study, the copper wires with diameter of 25um were bonded to aluminum metallization pad with ultrasonic power. The samples were then current stressed at an ambient temperature of 175°C. The results shows the increase of resistance was found to correlate with the growth of Cu-Al intermetallic compounds (IMC) and the voids observed between Cu/IMC interfaces. Additionally, the growth of the Cu-Al IMCs was strongly dependent on the direction of electron flow. The detail mechanism of electromigration induced failure on the copper wire bonding as well as interfacial reaction between Cu and Al will be discussed in this talk.