Packaging a top-cooled 650 V/150 A GaN power modules with insulated thermal pads and gate-drive circuit

This paper focuses on the design of a 650 V/150 A gallium-nitride (GaN) power module. Direct bonded copper (DBC) is applied as the insulated thermal pad to dissipate the heat generated by the GaN dies, where ceramics is employed for the thermal pad insulation. Printed circuit board (PCB) on the top of the GaN dies integrates the auxiliary power supply, the gate drive circuits and the decoupling capacitors, which can help the parasitic inductance reduction in the gate drive loop and the power loop to reduce the overshoot voltage across gate to source and drain to source. The packaged module exhibits high-current capability (150 A), high-compactness (45*33*9.6 mm3) and excellent thermal impedance from junction to heatsink. Taking advantages of the integrated gate-drive circuit, the proposed power module has simpler interface for users compared to regular GaN HEMTs on the market, which only needs PWM signal and non-isolated power supply to drive. To verify the electrical performance and thermal performance presented above, both double pulse test (DPT) and thermal test are conducted. DPT at 450 V/150 A shows around 54 V voltage spike only, which makes the proposed module suitable for high-power EV on-board charger or motor drive inverters.