Die bonded device and method for transistor packages

The specification describes a technique for die bonding that is tailored to air cavity plastic packages for high power devices. The die bonding method is simple and effective, and eliminates the step of placement of solder preforms in the die bonding operation. According to the invention the die that are to be attached are pre-coated with AuSn solder. A multifunctional bonding layer is applied between the silicon die and the AuSn bonding layer. The multifunctional bonding layer comprises a multi-layer structure including Ti/Pt/Au. The chip support member comprises copper or a copper alloy. The chip support member may also be pre-coated with a bonding layer. The pre-coated die is soldered to the chip support member.