Diamond single crystal-polycrystalline hybrid microchannel heat sink strategy for directional heat dissipation of hot spots in power devices

Aiming at the hot spots heat dissipation in power integrated circuits and challenging growth problems of large size single crystal diamond, a novel heat sink strategy is proposed, based on a diamond single crystal-polycrystalline hybrid microchannel for directional heat dissipation of hot spots. The numerical simulation results show that the distribution of radiator materials in different heat flux regions can greatly improve the overall temperature uniformity. Compared with the other two types of heat sinks, the heat dissipation performance of the diamond single crystal-polycrystalline hybrid microchannel radiator is improved by 61.8 % and 16.9 % respectively. And this advantage is more obvious in the case of high heat flux and large hot spot size. When the hot spot heat flux is 1600 W/m·K and the hot spot size is 5 mm × 5 mm, the maximum surface temperature of hybrid heat sink is only 336.5 K and 328.7 K, respectively, which is far lower than the device failure temperature. By microwave plasma chemical vapor deposition (MPCVD), 390 μm thick high quality bonding layer was obtained, and a diamond single crystal-polycrystalline hybrid microchannel heat sink was prepared. The heat dissipation scheme proposed in this study is a promising route, which is expected to improve the performance and stability of power devices through efficient directional heat dissipation, and will further promote the application of diamond materials in the field of heat dissipation.