Thermal Grease / heat sink insulators

[jteef]

Has anybody used Arctic Silver II Thermal Grease?
it is made for computer CPU's and they claim:

Thermal Resistance: 0.0028°C-in²/Watt (0.001 inch layer)

2 to 7 degrees centigrade lower CPU core temperatures than other thermal compounds.

http://www.arcticsilver.com
sells for 6 dollars / tube at http://www.newegg.com.

I am going to build a headphone amp/preamp based on THS6012 opamp but it is a surface mount part with a "heatsink" on the bottom of the IC that is supposed to be soldered to the ground plane. If I could just place a layer of this down(and super glue to hold it down) instead of drilling holes in the bottom and doing a half assed job of soldering it would help out a lot.

Talking about insulators in general now.

Looking through digikey catalog, there are about 10 different kinds of Berquist Sil-Pad. The most expensive being the K10 (there is also the KA10 which is newer, "better" but cheaper? Is it just an insulator and not a thermal conductor?) Are these parts meant to be used with a separate thermal grease (the K(apton) series) or are they keeping with the "alternative to grease" theme with them?

Then there are the mica insulators used with thermal grease. If Arctic Silver II is used, where do these fall?

Lastly, I guess I'll mention the beryllium oxide. Are these illegal in the US or not? If not, where to get?

Thanks

jt

[hifi]

hello i dont know how good it i for audio but i believe it is eleqtricaly conductive atleast to some extent?....and yes i must validate that it lowered my cpu core temp with 5-7degrees (duron 600@1010 )

/micke

[jduncan]

The best sil-pad is the A2000 however digikey does not sell it. I am currently looking for someone other than bergquist who does.

Arctic Silver is great however, as suggested, it is very electrically conductive so any designs would have to keep that in mind.

[PH104]

The BeO pads can still be found but hard to find. Newark has a few in stock but they list them as a discontinued item.

Try some of the surplus places - I bought a bunch of them from Hosfelt a few years ago. A search with Google should bring up a lot of hits, at least it used to.

Phil

[Super_BQ]

Why not use mica pads? If you want to isolate the device - it's hard to beat a very thin cut of mica and heatsink paste. Best of all you can cut mica to size and cost like nothing - (like $1 a pack of 10).

[cp642]

By the way...any one tried mounting transistors on a heavily anodized surface? ( minus the insulators and minimal thermal compound ) Should be better as it cuts down interface.

[Super_BQ]

cp642,

You can do that also. But keep in mind that the heatsinks will still be electricall live. For my pre-amp I hand cut and bent copper to the right shape. I had 1 mosfet and Caddock resistor mounted on each copper heatsinks. I only used straight heat transfer compound which works great!

[walker]

Supper idea, but not new. Infact NASA has used diamond, it has the lowest thermal resistance known, (from memory and I've warned you all about that before).
I have also used copper interfaces before, that is transistor direct to copper mica between the copper and aluminium. Do the math you'll find some prety low thermal resistances. The copper becomes the supply bus.

Regards WALKER

[cp642]

Brendon,
The intention is to use the heavily anodized surface as the insulating layer, The idea comes from DNM which uses Alumina blocks as insulators.

Hmm...diamond insulators...perhaps NASA should also consider silver heatsinks..

[Won]

I bet heatsinks designed to run in the vacuum of space operate rather differently than the typical heatsink where there's air to convect...

-Won