Investigation on the parallel operation of All-GaN power module and thermal performance evaluation

This paper presents a 270-V, 56-A GaN power module with three AlN substrates are prepared for the module. Each substrate is composed of three parallel connected GaN chips which incorporates six 2-A AlGaN/GaN-on-Si high electron mobility transistors (HEMTs) cells. The devices are wire-bonded in parallel connection to increase the power rating. The packaged GaN HEMTs exhibit the pulsed drain current of 0.435 A/mm. Both DC and pulsed current-voltage (I_D-V_DS) characteristics are measured for different connection and sizes of devices, at various power densities, pulse lengths, and duty factors. The static parameters of threshold voltage and leakage currents were extracted to show how these parameters would scale as the devices are paralleled. Performance of multiple chip GaN power module package and thermal evaluation is studied. Experimental results demonstrated the ability to parallel nine GaN HEMTs die together and to verify the current sharing during the dynamic switching to attain high-current capacities.