抄録
In order to reduce chip damage during bonding, high-temperature thick Al-0.5 mass%Cu wire bonding technology was investigated. In a previous study, we found that the reliability of the 300-µm-diameter Al-0.5 mass%Cu wire bonds was higher than conventional Al-Ni wire bonds. As the hardness of Al-Cu wire is higher than that of Al-Ni wire, the former has a higher possibility of chip damage occurrence. In this paper, by using a heated substrate, we have carried out thick Al-0.5 mass%Cu wire bonding and investigated chip damage occurrence and the reliability of the Al-0.5 mass%Cu wire bonds as a function of bonding temperature. Chip damage was evaluated by measuring the gate-emitter voltage. Al-0.5 mass%Cu wire joined at 423 K required the lowest ultrasonic power and shortest bonding time compared with 373 K and RT conditions. Also, Al-0.5 mass%Cu wire joined at both 423 and 373 K had the lowest number of damaged chips compared with RT. We also found that the reliability of Al-0.5 mass%Cu wire bonds joined at both 373 and 423 K was the same level as that of Al-0.5 mass% Cu wire bonds joined at RT.
