Depending on their shapes and materials, heat sinks can be made by many manufacturing methods. The most common and cost effective methods include extrusion, forging, casting and stamping. Other higher-cost methods include CNC machining, skiving and swaging. Although they are expensive, they can produce heat sinks with features that cannot be done by other methods.
Extrusion is the most cost effective process to produce heat sinks with plate fins. But additional secondary operation will increase its overall cost.
Cold forging is a highly precise process that can produce round pin and elliptical pin heat sinks. Thanks to the high pressure and low temperature, the forged heat sink has very good microstructure integrity.
Casting, especially die casting, can make heat sinks with complex geometries. But the material that can be casted has lower thermal conductivity than those employed in extrusion and forging.
Stamping is typically used in making tall heat sinks that require heat pipes running through the fins.
Skiving and swaging can be used to make special heat sinks. But because of the high price, they are only used in the applications where cost is not a sensitive factor.
CNC machining is a versatile manufacturing method that can produce heat sinks with the most geometric complexity, or parts that require urgent delivery, but the cost is often a disadvantage.