Performance of a GaN half bridge switching cell with substrate integrated chips

Wide-bandgap semiconductors such as Silicon Carbide (SiC) or Gallium Nitride (GaN) enable fast switching and high switching frequencies of power electronics. However, this potential can not be exploited due to limitations caused by parasitic elements of packaging and interconnections. This paper shows a possibility to minimize parasitic elements of a half-bridge switching cell with 650 V GaN dies integrated into a printed circuit substrate. A sub-nH commutation loop of 0.5 nH inductance gives superior switching characteristics compared to circuits with packaged dies. Simulation and experimental results of an inverse double pulse test confirm our expectations. This study further reveals additional benefits of the proposed technology in terms of mechanical stability and thermal interfacing to heat sinks compared to circuits with packaged dies.