An Embedded GaN Power Module with Double-Sided Cooling and High-Density Integration

Abstract

In this paper, an embedded GaN half-bridge power module with double-sided cooling, low inductance, low thermal resistance, on-package decoupling capacitors, localized common mode filter, and integrated gate drivers is proposed. The two GaN dies are embedded in a printed circuit board (PCB) with heat dissipation paths to a ceramic substrate from both sides of the devices to achieve double-sided cooling capability. Thermal and electrical performance are fully analyzed and optimized. A low-cost module assembly procedure is presented utilizing standard layer attaching process. Finally, a compact <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{2.7}\ \mathbf{cm} \times \mathbf{1.8}\ \mathbf{cm}$</tex> half-bridge GaN power module is fabricated to verify both electrical and thermal performance through experiments. The switching performance of the power module is tested under 400 V/25 A double-pulse test that shows the power loop inductance is as low as 1.03 nH and the overshoot voltage of the switching waveform is less than 5% of the dc bus voltage. The thermal resistance is verified to be 0.32 K/W, and the fabricated power module is employed in a buck converter with 500 W output power at 600 kHz switching frequency.