Diamond composite materials microchannel heat sink, used for efficient thermal management of silicon carbide power

With the wide application of SiC power devices in new energy vehicles, high-power conversion, and new energy systems, the massive heat flux they generate under high-power density conditions has become a key issue limiting device performance and reliability. Traditional metal heat sinks are no longer sufficient to meet the needs of SiC devices in terms of thermal conductivity efficiency and heat dissipation capacity, so the development of high-performance heat dissipation structures is particularly important. Diamond/copper composite materials have extremely high thermal conductivity and good processability. When fabricated into microchannel liquid-cooled heat sinks, they can achieve both rapid heat conduction and efficient convective heat transfer, providing a highly promising and efficient thermal management solution for SiC power devices.

This study adopted a process for preparing high-efficiency microchannel heat sinks using diamond/copper composite materials. By metallizing the surface of diamond particles and combining diamond particles with copper powder through hot-press sintering technology, the thermal conductivity of the composite material was successfully improved. During the sintering process, optimized pressure and temperature control ensured high density and excellent thermal conductivity of the material. Finally, active metal brazing technology was used to combine the diamond/copper substrate with copper microchannels, forming a high-efficiency heat dissipation structure. This diamond/copper composite microchannel heat sink has excellent thermal management performance and provides an innovative solution for heat dissipation of high-power density devices.

This study explores the improvement of interfacial thermal conductivity of diamond/copper composites through tungsten metallization and annealing treatment. The results show that tungsten coating is uniformly deposited on the surface of diamond particles, and annealing treatment promotes the formation of carbides, creating a tungsten/tungsten carbide transition layer. This layer effectively enhances the metallurgical bonding force between diamond and copper, thereby reducing interfacial thermal resistance and improving thermal conduction performance. In addition, fracture tests indicate that the interface of the tungsten coating maintains uniform particle distribution and avoids common debonding phenomena, providing strong support for enhancing the thermal management performance of the material.

SiC MOSFETs, DBC substrates, and heat sinks are tightly bonded using nano-silver paste to form a void-free and robust structure, ensuring excellent thermal conduction. Experimental and finite element simulation results demonstrate that the maximum junction temperature and surface temperature of devices equipped with diamond/copper heat sinks are significantly lower than those with copper heat sinks. The steady-state junction temperature is reduced by approximately 12°C, and the initial heating rate is slower, which helps reduce thermal stress. The high thermal conductivity and uniform heat distribution of diamond/copper composites enable SiC devices to operate stably under high power density while improving device reliability and efficiency.

By optimizing the interfacial bonding between diamond particles and the copper matrix, this study successfully prepares a diamond/copper composite substrate with a thermal conductivity as high as 807 W/m·K. The substrate is integrated with a sliced copper microchannel structure using an active brazing process, realizing the synergistic heat dissipation of high thermal conductivity materials and microchannel liquid cooling. Experimental results show that compared with traditional copper microchannel heat dissipation structures, this new heat sink can reduce thermal resistance by 39% and lower the peak junction temperature of SiC devices by 12.3°C, significantly improving heat dissipation performance and device reliability under high power density conditions. In the future, diamond/copper composites still have room for further improvement in interface regulation, structural optimization, and manufacturability, and their application potential in electronic systems with higher power and higher integration is worthy of in-depth exploration.

CSMH uses the MPCVD method to prepare large-sized and high-quality diamonds,and currently has mature products such as diamond heat sinks, diamond wafers, diamond windows,diamond composite materials,etc.Among them,the thermal conductivity of diamond heat sinks is 1000-2200w/（m.k）, and the surface roughness of diamond wafer a<1nm.It has been applied in aerospace, high-power semiconductor lasers, optical communication, chip heat dissipation, nuclear fusion and other fields.