Development of a directly bonded aluminum/alumina power electronic substrate

A process for manufacturing a directly bonded aluminum/alumina (DBA) power electronic substrate was developed in the present work. The bonding interface of the substrate was studied using transmission electron microscopy to elucidate the bonding mechanism of aluminum to alumina. The bonding strength, the wetting ability, the wire bonding capacity, the break down voltage and the thermal resistance of the DBA substrate were studied in comparison with those of a widely used directly bonded copper/alumina substrate. The results show that the DBA substrate has an excellent thermal cycle tolerance, and it is most suitable for assembling power electronic devices that are used under severe condition such as in vehicles.