1.2 kV SiC MOSFET Full-Bridge Power Module with Integrated Gate Driver and Coupled Inductor

Abstract

This work presents the design, prototyping, and characterization of a hybrid DBC/PCB-based 1.2 kV silicon carbide (SiC) MOSFET full-bridge integrated module building block (IMBB) with integrated coupled inductor and gate driver circuitry. Silver sintering and molybdenum posts are used to connect the SiC MOSFET dies to the gate driver PCB using a flip-chip assembly process. The IMBB has power loop and gate loop inductances of 4.5 nH and 1.6 nH, respectively. These low parasitic inductances allow the bottom switch to achieve 80 V/ns switching with a 4% voltage overshoot. Static characterization performed on the IMBB after the full packaging procedure has been completed indicates that all four dies in the full-bridge are functional. Silver-sintered MOSFET drains and the DBC substrate allow for junction-to-case and junction-to-ambient thermal resistances of 0.65 K/W and 1.18 K/W, respectively. The integrated coupled inductor's PCB windings are paralleled to reduce loss and internal temperature rise. The inductor has been tested to verify there is good current sharing in parallel windings. Following those tests, the inductor was tested in a 4.16 kW boost converter.