Thermal Interface Materials for Cooling High-Power Electronics

The Department of Energy is soliciting advancements in cooling high power density electronics such as RF devices used in the PIP-II MEBT beam deflector. GaN FETs in particular have a five times lower capacitance and five times faster switching speed than traditional MOSFETs, and thus are being integrated into particle beam choppers and beam deflectors at Fermilab. The thermal management needs of these GaN transistors are on the order of 200 W/cm2 each where multiple transistors are mounted on ceramic dielectrics. Accordingly, new cooling approaches are needed for these transistors that mate to the ceramic dielectric substrate and where there is no electrical conductance to or within the cooling system. To meet this market need, Skyhaven will produce two classes of thermal interface materials (TIMs). One class consist of aluminum nitride TIMs that will high thermal conductivity, yet be electrically insulative when mounted to the GaN transistors. The other class of TIMs are electrically conductive phase change materials that can serve as dual electrical traces while dissipating heat associated with periodic duty cycles. This Phase I project will produce and demonstrate these new materials with GaN transistors dissipating thermal loads upwards of 200 W/cm2.