A Novel High-Temperature Planar Package for SiC Multi-Chip Phase-Leg Power Module

This work presents the design, development and testing of a phase-leg power module packaged by a novel planar packaging technique for high temperature (250degC) operation. Nano-silver paste is chosen as the die-attach material as well as playing the key functions of electrically connecting the devices' pads. The electrical characteristics of the SiC-based power semiconductors, SiC JFETs and SiC diodes, have been measured and compared before and after packaging. No significant changes are found in the characteristics of all the devices. Prototype module is fabricated and operated up to 400 V, 1.4 kW at junction temperature of 250degC in the continuous power test. Thermo-mechanical reliability has also been investigated by passive cycling the module from -55degC to 250degC. Electrical and mechanical performances of the packaged module are characterized and considered to be reliable for at least 200 cycles.