Forced air cooling thermal design with embedded heat pipes in a heatsink for GaN-based High Power RF Amplifier Applications

This paper introduces an approach to efficiently manage thermal dissipation in gallium nitride (GaN) on silicon carbide (SiC) high electron mobility transistors (HEMTs). While GaN transistors possess a high temperature tolerance, it remains crucial to efficiently transfer the heat generated within the transistor-package to the external environment. In this article, a conceptual design for a heat sink is suggested with the aim of lowering the temperature of a GaN transistor module. ANSYS-Icepak software is used to conduct steady-state thermal simulations for forced air convection with different air flow rates, both with and without heat pipes embedded in a heat sink. The comparative simulation results for a 20 mm x 10 mm active area indicate a 31.5% temperature reduction from 100.2 °C to 68.6 °C in the transistor package with proposed embedded heat pipes. In addition to the temperature reduction, heat sinks with embedded heat pipes allow for a smaller form-factor heat sinks effectively dissipating the higher heat flux density from microelectronic packaging devices. The simulation findings also indicate that a heat sink of comparable size but without embedded heat pipes is not a viable option for effectively dissipating the 170.2W of power from the active packaging region of the GaN transistor.