Make your own diamond-based thermal grease

http://inventgeek.com/Projects/DiamondGrease/overview.aspx

by profquail • 17 years ago

19 5 17 years ago

rawr• 17 years ago

Oh man, your wife is going to be pissed when she finds out you disintegrated her engagement ring for your little computer machine.

jrockway• 17 years ago

That coating of thermal grease looks WAY too thick.

It also looks like he's measuring the temperature of the heat sink rather than the temperature of the die. If your thermal compound is acting as an insulator, then your heat sink is going to be nice and cold. (That smoke you smell is your processor melting through the bottom of your case, however.)

Finally, if you want to test heatsinks, it's better to use a resistive heating element instead of the CPU. You can't control how much heat the CPU is putting out (what with automatic frequency scaling and whatnot), but you can control how much current you are pumping through a resistor. Dan's Data has an article about this:

http://www.dansdata.com/coolercomp.htm

Retric2• 17 years ago

Residence increases as temperature increases, so better heat dissipation can dramatically reduce temperatures. Also if your heat sink is not working you have less than 5 seconds until this chip fries or shuts down to save it's self. So if the system boots then the heat sink really is working.

PS: Diamond is an great thermal conductor. (http://en.wikipedia.org/wiki/Thermal_conductivity) W/(m·K) Copper = 401, Silver = 429, Diamond = 900+

ajross• 17 years ago

I don't believe those temperature measurements for a second. Having a better-than-metal thermal conductivity is all well and good through the 0.1mm or so of grease, but the surfaces on either side of that are themselves metal, and much, much thicker than the grease layer. This is a misoptimization. It's the equivalent of tuning code that your application spends 1% of its time in. Who cares?

The purpose of thermal grease is to displace air, not to be better than the metal heat transfer parts.

Retric2• 17 years ago

I don't think silicone grease is anywhere as conductive as copper. While the 2 to 5 x increase in conductivity from using diamond is still fighting the bonding agent, it's probably helping more than you might expect.

Make your own diamond-based thermal grease

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