The main production processes of heat sinks include aluminum extrusion, die casting, precision cutting, welding, forging, etc. Different processes are suitable for scenarios with different material and performance requirements. The following are specific classifications and technical points:
Core molding process
Aluminum extrusion (Extruded)
The aluminum ingot is heated to 520-540℃ and then formed through a mold under high pressure, which is suitable for low-cost and mass production. However, due to material limitations, the thickness-to-length ratio of the fin does not exceed 1:18, and the heat dissipation efficiency is limited.
Die Casting
Molten aluminum liquid is injected into the mold for die casting, which can produce complex shapes (such as guide fins) and achieve thin and dense structures. However, it is necessary to balance the thermal conductivity of the material and molding defects (such as shrinkage cavities and oxide slag).
Precision Machining
The metal profile is cut by a special planer to form thick fins in one piece. Advantages include no interface thermal resistance, surface area increased by more than 50%, and coarse surface particles to improve heat dissipation efficiency.
Jointing process
Welding: Brazing or reflow soldering is commonly used to reduce the thermal resistance of the interface (such as lead-tin alloy filling the gap). High-end heat sinks may use high-frequency welding.
Folding/locking: After stamping the single fin, bend and interlock, or press and fix + screw, and fill the gap with thermal paste.
Forging
Filling the mold with aluminum blocks under high temperature and high pressure can produce high fins (>50mm) and thin thickness (<1mm). However, the equipment cost is high, and only a few manufacturers have mastered it (such as ALPHA, Taisol).
