Thermal interface materials with high thermal conductivity and low hardness are crucial to the heat dissipation of high-power electronics. In this study, a high magnetic field was used to align the milled carbon fibers (CFs, 150 μm) in silicone rubber matrix to fabricate thermal interface materials with an ordered and discontinuous structure. The relationship among the magnetic field density, the alignment degree of CFs, and the properties of the resulting composites was explored by experimental study and theoretical analysis. The results showed higher alignment degree and enhanced thermal conductivity of composites under increased magnetic flux density within a certain curing time. When the magnetic flux density increased to 9 T, the CFs showed perfect alignment and the composite showed a high thermal conductivity of 11.76 W/(m·K) with only 20 vol% CF loading, owing to the ordered structure. Meanwhile, due to the low filler loading and discontinuous structure, a low hardness of 60~70 (shore 00) was also realized. Their thermal management performance was further confirmed in a test system, revealing promising applications for magnetic aligned CF–rubber composites in thermal interface materials.

Concentrating photovoltaic power generation technology is a highly efficient way of utilizing solar energy resources with the efficiency limited by cell cooling conditions. For the heat dissipation problem from multi-point solar cell cooling, a microchannel heat sink is used to resolve the issue. Ammonia is chosen as the working fluid and two diamond microchannel heat sinks in series for the 16 simulated solar cells cooling with typical size. The heat sink consists of 31 triangular microchannels, each with a hydraulic diameter of 237 μm and a flow path length of 40 mm. It is experimentally verified that the diamond microchannel heat sink has excellent multi-point heat source heat dissipation capability. The surface temperature of the heat source can be controlled below 65.9 °C under the heat flux of 351.5 W/cm², and the maximum temperature difference between the multi-point heat sources is only 1.4 °C. The effects of heat flux, mass flux and inlet state on the flow boiling heat transfer capacity within the series heat sinks were investigated and the ranges of the operating conditions are as follows: heat flux 90.8–351.5 W/cm², mass flux 108–611 kg/(m²s), saturation temperature 15–23 °C and inlet temperature 15–21 °C. The results show that within the range of experimental conditions, the flow boiling heat transfer capacity of the series heat sink increases with the increase of heat flux and is less influenced by the mass flux, showing the typical two-phase heat transfer characteristics dominated by the nucleation boiling mechanism. Between the upstream and downstream heat sinks, the thermal resistance of the upstream heat sink is larger and the temperature uniformity of the downstream heat sink is poor because of the difference of the inlet state.

With the rapid development of microelectronic technology, airborne electronic equipment is developing towards high performance, high power and miniaturization. High-heat-consumption chips pose a new demand for heat dissipation. Micro-channel evaporator and low-temperature brazing technology provide a new solution for this demand. Through experiments and numerical calculations, the effects of microchannel structure and boiling characteristic parameter on heat transfer performance are analyzed. Results show that the microchannel is capable of reducing heat transfer temperature difference by 18%, and large aspect ratio can improve heat transfer performance of micro-channel evaporator. Braze welding interface can obtain high interfacial heat transfer coefficient, with overall heat transfer coefficient up to 3~4 W/cm2K.