Instead of extruding, forging, or milling fins, it is also possible to simply use copper (or aluminum) plates as fins, and bond them on a base plate. If each fin is made of a separate plate, we refer to such heatsinks as bonded fin heatsinks. If all fins are made of one large plate that is folded to form the fins, we have a folded fin heatsink. Advantages of such heatsink designs include high surface, and low weight. However, the performance is only good if the bonding is done properly.

"bonded fin" heatsink