In thermal management systems, the core function of a heat sink is to efficiently conduct and dissipate heat. Its performance largely depends on the thermophysical properties, processing adaptability, and environmental tolerance of the materials used. Currently, the mainstream materials in the industry include aluminum alloys, copper, copper-aluminum composites, and new high thermal conductivity composite materials, each with its own advantages and suitable for different application scenarios.
Aluminum alloys are the most common choice for air-cooled heat sinks due to their lightweight, moderate thermal conductivity (approximately 160–230 W/m·K), good processability, and controllable cost. Extrusion molding processes can mass-produce regular fin structures to meet the heat dissipation needs of large-scale electronic equipment and general industrial equipment. After anodizing, corrosion resistance is significantly improved, making it suitable for normal temperature or moderate humidity environments. However, pure aluminum has lower thermal conductivity than copper, and its performance is prone to bottlenecks in high heat flux density applications.
Copper is renowned for its excellent thermal conductivity (approximately 390 W/m·K), enabling rapid lateral transfer of heat from concentrated heat sources to large-area heat dissipation surfaces. It is widely used in high-power chips, power electronic modules, and liquid cooling plates requiring compact designs. However, its density and cost are higher than aluminum, resulting in greater tool wear during processing and more stringent welding and sealing requirements. To balance thermal conductivity and lightweight design, the industry often employs copper-aluminum composite structures, such as copper base plates with aluminum fins, ensuring efficient heat conduction in the heat source contact area while reducing overall weight and manufacturing costs.
With the increasing demands for thermal management, some high-end fields are introducing high thermal conductivity graphite, diamond composite substrates, or ceramic matrix composites. Graphite exhibits anisotropic thermal conductivity, exceeding 400 W/m·K in the planar direction, making it suitable for space-constrained scenarios requiring directional heat dissipation. Diamond composite materials can achieve thermal conductivity of 600–2000 W/m·K, but due to processing difficulty and cost, they are mostly used in aerospace, microwave, and other specialized fields. Ceramic materials such as aluminum nitride and silicon carbide possess both high thermal conductivity and excellent insulation, making them suitable for heat dissipation needs in high-voltage isolation or high-frequency operating conditions.
Material selection requires comprehensive consideration of heat load, space constraints, weight limitations, corrosion resistance requirements, and economic efficiency. For example, consumer electronics tend to favor lightweight aluminum to optimize portability, industrial transmission and energy devices prefer copper to handle continuous high loads, while cutting-edge technology fields are exploring new materials with ultra-high thermal conductivity to break through heat dissipation limits. Understanding the characteristics of various materials and their compatibility boundaries helps in precise matching during the design phase, achieving efficient and reliable operation of the thermal management system, and providing a solid foundation for equipment performance improvement and industrial upgrading.
