What's that stock thermal stuff in use on new heatsinks?

[MikeHelvey]

I just put a T-bird into a KT7. The heatsink came preloaded with a yellow thermal past (actually hard stuff) under a piece of plastic. It apparently softens with heat and smushes out from between the heatsink and core from the pressure applied by the clips.

What the heck is this stuff? Is it comparable to thermal tape, grease, or paste? I have a couple tubes of thermal grease (aluminum) that I thought about using, but figured I didn't want to chance getting any on the bridges since it is conductive.

Mike Helvey

 

[DaddyG]

Mike,

You don't say what brand of hsf you are using but most AMD approved hsf's come with Phase Change Thermal Compound pre-applied. Many hsf manufacturers use Chomerics T725 but its pink not yellow. PCTC goes through a permanent 'change' at a pre-set temp, going from semi-sold to 'bubble-gum like, as it does this it fills micro gaps between the hsf and the cpu. Unlike many silcone based 'greases' which can dry out under the temps of a TBIRD, PCTC is based on Paraffin Wax and withstands the high temps for much longer.

 

[MikeHelvey]

Thanks - I don't really remember what brand hsf I received. The paste was yellow and acted exactly like you said. I was just a little concerned since I hadn't read about or seen this kind of stuff before. Sure looks like it will be a world better then thermal tape, and possibly grease if it fills in like you said!