How do you attach a copper plate to aluminum heatsink?

[Über~PhLuBB]

Does anyone know how? It's not like I have an ultra high powered hydraulic compression machine so I could smash the two together (That wouldn't work anyway, it'd flatten the fins).

Is there a simple, yet very effective way to attach the two? I dont think Epoxy is the answer.

I'm making a HSF for my coming GF3, but the aluminum heatsink's base is rather thin due to my having to file off some anodizing, then subequently lapping the bejesus out of it. (Can you say "mirror-faced aluminum"?:D)

Bolts maybe? 4 bolts around the edges would hold it tight, but that could mash the edges down, forcing the center of the HSF up into a sort of "bubble" leaving a void between the two materials -- unacceptable.

Ideas? Suggestions? Comments?

[Owenator]

I have used the bolt idea with some white thermal grease between the two with limited success, but it works better if you use a good metal epoxy like JB Weld. JB Weld worked great for me but first I lapped both metals and then lapped them together by doubling up some sandpaper and putting it between them and then rubbing them together. After that I mixed up the JB Weld applied it thinly and clamped them together. I set the clamp on top of my water heater to get it to cure faster, I still left it there over night. I successfully attached 1/8" copper plate to a generic TBird HSF and also A GlobalWin FOP-32. I even bought some Artic Silver adhesive but I haven't tried it yet. I know the AS adhesive is made for good heat transfer and I know the JB Weld has metal in it also. Hope this helps.

O

[Colin]

As long as you don't deform the copper plate, bolts and Arctic Silver II would be your best bet. Any epoxy is not going to transfer the heat as well as a Arctic Silver's grease. Remember, you will be adding another thermal interface. You may be better off just using the aluminum base of your current HS.

JB Weld is epoxy with steel particles in it. We all know how well steel transfers heat.... A better choice would be Arctic Silver Epoxy as it has silver in it for better thermal conductivity.

[Über~PhLuBB]

Currently, the heatsink's base is about 2-2.5mm thick. That's pretty damn thin. Instead of adding more alimunim, I thought copper would be better.

As for Arcic Solver epoxy, I have 2 questions.

1) Does it transfer heat as efficiently as Arctic Silver II, and if not, please gime me an estimate percentage. (I.E., ACepoxy is 96% as effective)

2) Does Arctic Silver Epoxy hold onto both aluminum and copper as well as JB Weld would? I'd guess the head transferring additives would dampen the holding ability, but I dont know (Hence me asking)

[Owenator]

Take a look at http://www.arcticsilver.com .

There is info on the adhesive and grease properties. If remember correctly they are pretty close.

I didn't know JB Weld was not so good, it seemed to work fine for me? I switched to water cooling anyway and I am not going back!

O

[Owenator]

I got these numbers from their web site.

Arctic Silver Grease:
Thermal conductivity: 8.4 W/m°K to 8.8 W/m°K
Arctic Silver Adhesive:
Thermal conductivity: 7.5 W/m°K

Looks like the adhesive has about 85-90% of the Thermal conductivity of the grease.

You should double check because I don't want to mis-represent this excellent product. I saw an email from the owner here once (I think) and I'm sure he would correct me if I was wrong.

O

[Über~PhLuBB]

lol.. I just noticed all those typos. I've was up all night laaping the HSF. Need sleep...