Carbon Black thermal compound??

[Upstream]

I've found an article at ZZZ Online:
http://zzz.com.ru/art174.html

Does any one know if someone is making this stuff or where to find carbon black?

 

[pspada]

no linkie, no clickie.

 

[Jeff7]

Solution to un-URL'd links

 

[Upstream]

Erm..? I'm new to this.

Working link?:

 

[beatle]

Looks promising, at least from the article. Is it in production yet? The article was written 2 months ago.

 

[beatle]

Bump for the interested.

<---- interested

 

[Upstream]

Nope. Not as far as I know.
Maybe I should put the recipe up for all the budding chemists?

 

[beatle]

Couldn't hurt! Let me find out that it's pencil lead and vaseline.

 

[Upstream]

Chung Snip:
"Abstract
Carbon black dispersions based on polyethylene glycol (PEG) or di(ethylene glycol) butyl ether, along with dissolved ethyl cellulose, provide thermal pastes that are superior to solder as thermal interface materials. The thermal contact conductance of the interface between copper disks reaches 3 x 10^5 W/m2.°C, compared to 2 x 10^5 W/m2.°C for a tin-lead-antimony solder...

Materials
The polyethylene glycol (PEG, or HO(CH2CH2O)nH) used as an organic vehicle was PEG 400 from EM Science (Gibbstown, NJ). It had an average molecular weight of 400 amu; this average value corresponds to n ~ 8.68. It was a liquid at room temperature and optionally contained ethyl cellulose (E8003, Sigma Chemical Co., St. Louis, MO) at either 3 or 5 vol.%. The ethyl cellulose was a white powder that was dissolved in the vehicle. It served to improve the dispersion and suspension of the solids in the pastes....The carbon black used was Vulcan XC72R GP-3820 from Cabot Corp., Billerica, MA. This carbon black was chosen due to its electrical conductivity and easy dispersion...

Conclusions
The use of a PEG-based paste (containing 3 vol.% dissolved ethyl cellulose and dispersed carbon black in the optimum amount of 1.25 vol.%) as a thermal paste between copper disks results in a thermal contact conductance of 30 x 10^4 W/m2.°C, compared to a value of 20 x 10^4 W/m2.°C for tin-lead-antimony eutectic solder applied in the molten state...


"

Easy to make once you have the ingrediants, which seem easy to get.
The full document is available for download from the link in the first post:
Chung Carbon Black
Dont forget my cut when you start selling this stuff!

 

[spclwpns]

This carbon black was chosen due to its electrical conductivity and easy dispersion...

Red Flag for me...... I don't use conductive paste or one of "easy dispersion", but I suppose someone will make use of something like this..... LOL

 

[WarCon]

The principle is a good one, thin as possible thermal layer. I guess what I am having problems with is why adding carbon to the mix is any better than just using the base by itself. Are we seeing some kind of reaction or material in suspension effect going on? Or are we seeing some poor test results?

I also have to guess that the reason the solder joint was poorer than the carbon based was the thickness of the thermal layer. If they heat compressed the solder joint to the same thickness as the carbon black I am sure it would perform equally or better.

So it really all comes down to the thinnest layer (that will hang around under heat and pump out conditions of small core processors) is always gonna be the winner even if its vegemite (I am sure it probably dries out though)..........

We aren't talking magic here, a good thermal layer is going to be thin. A poor one is going to be thicker. If anyone has actually done the math a similar properly applied thickness thermal layer of almost any compound is going to yield within 1C of each other (there was a decent website about this). Small cores though are a totally different beast. They flex as they heat and cool so the surface goes from flat to convex. A thermal compound has to have some thickness in this circumstance in order to maintain contact during the flex times. This is the only time you will see a significant difference in compounds.

When I see tests that this compound lasts more than a year or two under normal use without drying or being pumped out, then I will give a thumbs up.

One thing to think about is......Has anyone actually played with carbon black (I have) and man that stuff is messy and is conductive.

 

[DurocShark]

I don't like the pressure required to get the results posted. It would require a redesign of the CPU packaging to be able to resist that pressure...