A 400W, 250kHz (2kW Peak) Integrated GaN Half Bridge Power Module in a Non-Isolated Buck Converter

This work demonstrates the design, fabrication, and electro-mechanical performance of a 60V/400W/250kHz Buck Topology-based GaN Half Bridge power module using high thermal conductivity thin organic substrates. The module integrates GaN power devices, gate driver, bypass capacitor, bootstrap capacitor, diode, resistor, and power decoupling capacitors into a power-dense package for increased performance. Thermally the module produces 97% efficiency under hard switching with forced air cooling. ANSYS Q3D parasitic extraction revealed a 2.7nH DC power loop inductance and 2.5nH at the switching frequency (250kHz). A Double Pulse Test (DPT) verified high switching speed performance at an instantaneous 2kW, i.e., five times than rated steady state buck operation. Finally, an FEA-based thermo-mechanical analysis was carried out to predict the package’s stress distribution and mechanical reliability.