A High Performance GaN Power Module with Parallel Packaging for High Current and Low Voltage Traction Inverter Applications

Gallium nitride (GaN) power semiconductors are being explored as promising alternatives for the next generation of high-power traction inverters, suitable for both high- and low-voltage applications. In such scenarios, the peak current can reach several hundred amps. Hence, using multiple GaN HEMT chips or dies in parallel is definitely a design approach to extend power capacity and minimize power losses. However, the parallelization and packaging structure of GaN devices present numerous challenges. Achieving balanced dynamic and static current sharing between paralleled devices, as well as ensuring robust gate driving signals, is indispensable for reliable operation during high dV/dt and di/dt transients, particularly with switching noise-sensitive gate-source threshold voltages. Additionally, thermal dissipation and mechanical stress must fulfill industrial requirements. This paper introduces a compact 100 V/360 A GaN power module specifically designed for packaging on insulated metal substrates (IMS) or direct-bonded copper (DBC). The proposed packaging approach offers superior electrical performance, excellent thermal dissipation, minimal mechanical stress, and a cost-effective solution. Finally, the advantages of the proposed power module design are validated through various experimental setups, including a 48 V/328 A double pulse test, a 48 V/24 V 3 kW buck converter implementation, and a 48 V/5 kW three-phase inverter demonstration.