For high volume production, zipper fins are the most cost efficient method for high fin density heat sinks. These fins are made from a stamped material, typically aluminum or copper, and are folded into shape with interlocking grooves. The fins are then typically soldered, brazed, or epoxied to a base or used in part of a cooling system.
This process allows for more structurally stability while allowing for very high fin densities and fin aspect ratios, therefore increased surface area and better cooling. Zipper fins also allow for increased design flexibility, especially with integrating heat pipes or ducting for fans or blowers.