PCB Only Thermal Management Techniques for eGAN® FETs in a Half-Bridge Configuration.

Abstract:
Cost constraints for low power GaN FET based converters limit the use of heatsink options for cooling, thus requiring the Printed Circuit Boards (PCB) to become the primary path for heat flux exchange. Various design options to minimize thermal resistance between the junction of a GaN FET and ambient are analyzed. Options include thicker copper, thermal vias to utilize the bottom-side copper for cooling, FET separation, and layout design to maximize heat-spreading are investigated. Proper implementation of these techniques can reduce thermal resistance from the junction to ambient (R(thetaJA)) by up to 30% with little to no additional cost.