Assembly and packaging technologies for high-temperature and high-power GaN devices

This paper gives a detailed analysis on the assembly and packaging technologies for the state-of-the-art GaN-based high-electron-mobility transistors, which are suitable for high-temperature and high-power applications. Silver sintering and transient liquid phase bonding were selected as die-attachment techniques, and gold and palladium were investigated for electrical interconnection materials. Both the die-attachments were characterized for their high-temperature stability up to 450 degC. Systematic electrical characterizations were performed from on-wafer measurements to the final assembly. The thermal and thermomechanical influences of the assembly were assessed. For die-attachments and interconnections, passive temperature shock cycling and active power cycling were performed as an initial attempt to characterize the assembly reliability. Finally, a complete package along with the base plate was proposed, which can survive high temperatures up to 480 degC.