How are heat sinks machined

1. Material selection: balance between performance and cost
Copper vs aluminum
Copper: The thermal conductivity is about 400 W/m·K, and the thermal conductivity is the best, but it has a high density (8.96 g/cm³) and high cost, and is mostly used in scenarios with extremely high heat dissipation requirements (such as CPUs/GPUs).
Aluminum: Thermal conductivity of approx. 237 W/m·K, low density (2.7 g/cm³), easy processing and low cost, suitable for large-scale applications (e.g. LED luminaires).
Composites: The combination of copper and aluminum (such as gear shaping process) takes into account both performance and cost, and the interface thermal resistance tends to be close to zero, which is widely used in high-power electronic equipment.
Emerging materials
Graphene coating: to improve the surface radiation efficiency, but the process is complex, mostly used in aerospace.
Phase change materials: use liquid-gaseous phase change to absorb heat and are suitable for instantaneous high heat flow scenarios (e.g., lasers).

2. Geometric design
Pitch to thickness ratio: 3:1 is the best heat dissipation efficiency, too small increases the flow resistance, too large reduces the surface area.
Arrangement: Parallel arrangement is better than staggered arrangement (20% higher efficiency), vertical arrangement is better than horizontal.
Forced convection: Match the fin spacing with the fan speed (e.g., server fan speed≥ 5000 RPM).
Surface treatment
Alumite increases emissivity, but contributes only to forced convection.
Acid-resistant aluminum treatment enhances corrosion resistance and is suitable for coastal or industrial contaminated areas.

3. Industry application: scenario-based technology adaptation
Consumer electronics
Mobile phone/PC: Aluminum extrusion heat sink is the main one, with a thickness of <2mm, and graphene patches are used to improve local heat dissipation.
High-power LED: The efficiency of the phase change heat sink (boiling structure) is increased by 40%, and the microchannel design is required.
New energy vehicles
Battery thermal management: liquid-cooled aluminum heat sink copper tabs, coping with 400V high-voltage platforms.
Motor controller: Cold-forged copper heat sink, resistant to vibration and thermal shock.
Aerospace
Satellite payload: titanium alloy heat sink (lightweight), silver plating on the surface to reduce radiant thermal resistance.
Radar system: Diamond/copper composite, coping with extreme temperature gradients.
Medical equipment
MRI/CT equipment: copper-tungsten alloy heat sink, shielding electromagnetic interference, suitable for compact space.

4. Future trends
Extreme process: CNC cutting thickness < 0.2mm fins, and the heat dissipation efficiency per unit area is increased by 50%.
Intelligent design: AI optimizes fin topology, combined with CFD simulation to shorten the development cycle.
Sustainability: Recycled aluminium heat sink (80% recycled material) reduces carbon footprint by 30%.