Folded fin heat sink is very similar to bonded fin heat sink, but the fin is much thinner (REF 0.5mm). In the past, we proposed folded fin to replace bonded fin when there is weight constrain in our clients’ application. We are using soldering instead of thermal epoxy to assemble the fin to the base of heat sink. Rule of thumb is we must have more than 80% of fin base to heat sink base in contact with x-ray scan. Aluminium fin must be nickel plated to enable soldering to the base.
This again will not optimised our heat sink performance and today’s extrusion processes are able to produce very thin fin like what we had in folded fin with similar fin ratio.
We had helped one of our major clients to reduce cost significantly by replacing their folded fin design with extrusion design of similar geometry without affecting heat transfer efficiency. Result of the change: saving heat sink cost by more than 60%!