Ultra-Fast and Ultra-Compact Driver-Integrated GaN Half-Bridge Module With Insulated Top-Side Cooling

Abstract

This paper presents a 200-V GaN ultra-fast and ultra-compact gate-driver-integrated half-bridge power module with insulated top-side cooling. Repackaging GaN devices to build GaN half-bridge power modules is drawing more interest for high-power GaN applications. However, repackaging GaN devices has several major challenges: reducing the power loop and gate driver loop inductances, reducing the thermal resistance, and reducing the cost and complexity of the assembly process. This paper proposes a simple and low-cost method to develop GaN half-bridge module. This GaN module optimises the power loop inductance with a minimised size of DC decoupling capacitors. This GaN module also integrates two commercial 0.8 mm x 1.2 mm 7A gate drivers to maximise the switching speed. This GaN module uses a low-cost aluminium PCB as the heat spreader on the top of the devices with insulation. The two PCBs are simply connected and pressed through several miniaturised copper solder pins. The developed gate-driver-integrated GaN half-bridge power module has a total size of 15 x 15 x 2.6 mm³, including two 200 V and 22 mOhm GaN devices, two gate drivers and DC decoupling capacitors. This GaN module has only 0.32-nH power loop inductance and achieves 266 V/ns maximum turn-on speed. The thermal resistance of the device was decreased from 75${}^{\circ }C/W$ to 34.6${}^{\circ }C/W$, and this amount was further reduced to 16.4${}^{\circ }C/W$ by the addition of a heatsink.