Engineering Design of a Near Junction Thermal Transport Heat Spreader

This paper describes a convection-based, self-contained heat spreader that provides device-level thermal management for GaN power amplifiers. The concept connects microchannels etched into the backside of the die to a liquid flow circuit that includes autonomous flow-balancing valves, a diaphragm pump, and a high-performance heat exchanger. The integrated system provides a heat spreading capability that reduces transistor gate heat fluxes by up to four orders of magnitude, enabling device-level temperature control using conventional cold plates. This paper will review the analysis used to design the key components in the assembly and to project their performance as part of an integrated system.