Zipper fin heat sink is an assembly of a base and a fin stack that are soldered ,brazed or epoxied together.These zipper fins are created using a set of individually stamped fins which are folded into shape with interlocking grooves. Zipper fins can be manufactured from either copper or aluminum and it is possible to mix the different materials within a fin stack. The base can be either aluminum or copper as well.The finish is either a nickel plate or a chromate, either of which will improve the thermal performance and provide environmental protection.
Zipper fin heat sink have good thermal performance due to  it allows  with high fin desities and fin aspect ratios. and it is also have design flexibility , expecially with integrating heat pipes  or ducting for fans or blowers