Building our own heat sink 1

[Baheej]

We are considering building our own heat sink inhouse to try and cut most of the custom work cost. The heat sink will mostly be a sandwiched folded fin between two sheets. My question is: how and what is the best way to attach the fin to the sheets? Brazing, spot welding, ...etc. This part can be outsourced, but we don't know what is the best way to get the best efficiency. Any ideas?
Thanks.

 

[ko99]

It's best to have a continuous connection along the length of the fin-to-sheet interface.

Braze, solder, press-fit and and in some cases, even epoxy will give better results than spotwelding.

Spotwelding will have nearly perfect contact but only at the point of the weld -- the rest of the interface will have microscopic (or larger) air gaps, and air is an excellent thermal insulator.

Epoxy is tempting because of lower cost. It can be thermally effective IF the epoxy thickness is minimal AND the contact area is high. Some designs achieve this by fitting the "U" of each pair of folded fins tightly into shallow channels machined or extruded into your sheets.







ko (

http://www.ecooling.biz)

 

[Baheej]

Ko,
It seems that there are some practical concerns with building the heat sink inhouse, that we really prefer have someone else worry about them. May be we should get it built by a professional. Thanks.

 

[IRstuff]

I concur. You should be able to find house that can make a unitary heatsink, which, at the volumes that you were presumably anticipating, will be better economically as well.

TTFN