A 650V/60A Gate Driver Integrated Wire-bondless Multichip GaN Module

Lateral Gallium Nitride (GaN) high electron mobility transistors (HEMT) exhibit lower on resistance and high switching speed due to the presence of 2D electron Gas and smaller capacitance. Moreover, the high critical electric field of GaN makes it excellent choice for power semiconductor devices. It has the capability of switching hundreds of volts in nanoseconds, giving it multiple megahertz capability. However, to enable this feature, advanced packaging structure with optimized stray parameters is required. The traditional wire-bonded package of power module has large parasitic inductance, which will cause voltage overshoot, oscillation, parasitic turn-on, and EMI issues. A gate driver integrated wire bondless solution for a GaN half-bridge, phase-leg module is presented in this manuscript. A global optimization is done to achieve 0.68 nH power loop inductance, 1.25 nH gate loop inductance and 0.257°C/W thermal resistance. The hybrid combination of printed circuit board (PCB) and direct bonded copper (DBC) substrate enabled vertical commutation loop, which has helped to limit the stray inductance substantially. The fabricated module shows excellent switching performance with turn-off speed as high as 192 V/ns while not exceeding the voltage overshoot more than 15% of applied DC link voltage.