A numerical study on die-integrated manifold microchannel heat sinks considering transistor-level heat dissipation of gan based mmic devices

Official URL: https://dx.doi.org/10.1115/ipack2025-164114

Continuous endeavors towards the miniaturization of electronics pose new challenges in the thermal management of devices achieving high-power density. In that regard, navigating the coolant closer to gate fingers becomes an effective approach to handling concentrated heat in small footprints. Therefore, with the increasing popularity of gallium nitride (GaN) based devices among high-power density electronics, the idea of die-embedded microfluidic structures can be considered a promising solution for hotspot mitigation on a small scale. To surmount the thermal limitations of GaN-based devices, previously studied microchannel heat sink structures are ameliorated by integrating manifold microchannel heat sinks (MMCHSs). The present work alternatively focuses on diminishing excessive pressure drop values reported in the preceding study by implementing MMCHSs having non-uniform distribution of manifold branches. While diminishing excessive pressure losses with the integration of selected manifold microchannels, it is also crucial to preserve the thermal performance of the entire microfluidic structure. Therefore, considering non-uniform and localized power dissipation on the surface of monolithic microwave integrated circuits (MMICs), several MMCHSs with nonuniform manifold inlet and outlet distribution are proposed. Findings reveal that non-uniform branches of MMCHSs designed with the consideration of local heat dissipation not only exhibit up to 88% reduction in the device-level pressure loss but also preserve thermal performance with slight differences. Results and strategies presented in this work are anticipated to provide substantial benefits for researchers endeavoring to use appropriate microchannel heat sinks to address emerging hotspot mitigation challenges in high-power density electronic devices.