Pro/Forums - Using H2O as thermal compound.

Pro/Forums (http://forums.procooling.com/vbb/index.php)

- General Liquid/Water Cooling Discussion (http://forums.procooling.com/vbb/forumdisplay.php?f=9)

- - Using H2O as thermal compound. (http://forums.procooling.com/vbb/showthread.php?t=9802)

Quote:

Originally Posted by CheeseBall

Hmm, so how did you apply the water? Did you just put some drops on the die and seal around it, then mount?

After I made the bead of noncondutcive grease encircling the die, I put a single drop of water on the center of the die then carefully mounted the waterblock. You don't want to make the bead too thick nor too close to the die. I practiced with a 2 inch square of plexiglass over the cpu (removed from the socket) to make sure the seal was consistant and that the water didn't squirt past the seal when I applied pressure.

P.S. I should mention that I did this all a couple of years ago with a palamino processor which didn't have anything mounted on the surface of the cpu, unlike the newer athlons. The clear tape I used may not work so well for you.

Quote:

Originally Posted by freeloadingbum

I disagree. Water should be better at filling in the micro-crevices due to it's low viscosity, leaving less air bubbles. Also because of the ultra thin layer water will produce, it's thermal conductivity shouldn't matter much. My personal tests showed ~3C improvement compared to multiple mounts of AS3 (using cheap testing equipment of course)

I sealed the top of the processor package using a wide piece of clear tape (cutting a hole for the die) then I made a bead of dielectric grease circling the die to create an air tight seal between the processor and the bottom of the waterblock, preventing the water T.I.M. from leaking or evaporating.

I didn't do any long term tests using water as I wanted to try Fluorinert FC40 as a substitute since it's non conductive. Unfortunatly I had no luck in getting a sample.

Water contains a lot of dissolved gases which will tend to collect on the surfaces of your cpu/block and cause much lower performance though. Just try leaving a glass of water for a day or two - you'll notice a lot of air collects on the surfaces of the glass.

Quote:

Originally Posted by Butcher

I'm sure if I could fit an entire glass of water on my cpu that gas bubbles may become a problem (j/k). Even when using a single drop, most of the water is squished out. I don't see gas being a problem but I do see pumpout being a potential problem.

Quote:

Originally Posted by freeloadingbum

I disagree. Water should be better at filling in the micro-crevices due to it's low viscosity, leaving less air bubbles.

The low viscosity will leave a very thin layer, but the high surface tension (and the fact that neither silicon nor copper wet really well) will mean a tendency to bridge the micro-crevices instead of filling them.

Now if you'd used glycol, with its excellent wetting and hardcore capillary action...

Quote:

Originally Posted by Groth

I would think that the mounting pressure would be enough to overcome any surface tension as my results seem to indicate but perhaps glycol would be even better.

I think most of the mounting force would be transmitting by the areas of direct block-die contact. Water would squirt out rather than be pressurized. And I think that's why you got good results -- minimal TIM, maximum contact.

The way to find out is to test with a range of mounting force. Compression of the trapped air (less volume, higher thermal conductivity) is one of the ways TIM joints improve with greater force (I don't think water would be as subject to the 'more pressure = thinner TIM' mechanism like high viscosity goops).

I just wanted to say that most of the air in which ever liquid you use will float upward w/ some vibration. So that would leave the air all on once side of the die w/ a mid tower case (depending how the socket is positioned). And we could allow enough room between the die and the seal for the air to remain w/ out affecting thermal contact. It will be the difference between thermal contact and thickness of TIN VS. thermal conductivity.

So if/when I try this out any other liquids worth trying?