A Gallium Nitride Integrated Power Module with Ultra-low Parasitic Inductances and Thermal Resistance

In recent years, gallium nitride (GaN) high electron mobility transistors (HEMTs) has been widely adopted in fast chargers, showcasing their potential in promoting efficiency and power density. However, as power level increases, especially beyond 10 kW, it becomes crucial to address not only parasitic inductances but also the thermal performance seriously. In this work, a GaN integrated power module (IPM) with ultra-low parasitic inductances and thermal resistance is presented. To minimize parasitic inductances, a 6-layer printed circuit board (PCB) is employed, strategically designed to optimize the layout and reduce unwanted inductances. A water-cooling heatsink is also integrated to eliminate conventional thermal interface materials (TIM) with low thermal conductivity. The measured power loop inductance of the proposed module is only 0.54 nH. Moreover, the simulated junction to case thermal resistance is impressively low, which is only 0.05 ℃/mꞏW.