Advanced Heat Spreader Technology for Gallium Nitride (GaN) Monolithic Microwave Integrated Circuits (MMICs)

Electrical systems are being designed with ever increasing power densities, particularly future radar and electronic warfare systems built with Gallium Nitride on Silicon Carbide Monolithic Integrated Circuits (GaN MMICs). Today’s GaN MMICs use solid metal, low-coefficient of thermal expansion heat spreaders (e.g., Copper-Tungsten). But solid-state heat spreaders cannot meet the size, weight, power and cooling requirements of next-generation GaN MMIC applications without undesirable tradeoffs. ThermAvant proposes to efficiently diffuse high heat fluxes from GaN MMICs using micro-loop Oscillating Heat Pipes (OHPs). OHPs are a passive, two-phase heat transfer technology capable of handling very high heat fluxes using a wide range of material-fluid combinations. This specific effort aims to miniaturize OHP features to effectively dissipate tens-to-hundreds of Watts from millimeter-scale GaN devices. ThermAvant will work with the Navy and system integrators to ensure the to-be-developed micro-loop OHP spreaders meet the thermal-mechanical requirements of real-world radar/electronic systems as well as economic and manufacturing specifications.