高温环境下电子设备相变热沉设计研究

In this paper, a solid-liquid phase change-based heat sink with composite fin design is proposed for electronics operating under high-temperature enclosed environment at 80^◦C. The effects of three thermal conductivity enhancers on the thermal management performance are compared using numerical simulation, including composite fin structure, the addition of copper foam high thermal conductivity matrix, and addition of carbon bonded carbon fiber high thermal conductivity matrix. The results show that when the heat flux is at 2.45 W·cm⁻², the heat sink with composite fin structure has the longest operation time and the lowest average operating temperature. The experimental study was carried out by preparing heat sink sample through metallic additive manufacturing, and the experimental heat flux ranged from 0.82 to 2.45 W·cm⁻², and the robustness of the simulation was verified by comparing it with the numerical simulation results. At the maximum heat flux, the heat source can operate 240 s until it reaches cut-off temperature of 105^◦C. The phase change material fully melted at the cut-off temperature, which verifies the effectiveness of the composite fin structure.