Thermal paste

TVeblen said:

If your brain works better with concepts than with rules then this sage advice that I got from a fellow geek many moons ago has always worked for me:

If you look at a seemingly smooth piece of metal under an electron microscope you will see that the surface actually looks like a mountain range - many peaks and valleys.
To have perfect heat transfer the two metal surfaces should be touching on 100% of the surface area of both plates.
But when you go and try and mate the two metal surfaces together the peaks and valleys create voids that greatly reduce the thermal transference.
The purpose of thermal paste is to fill those peaks and valleys, at that microscopic level, to increase the total contact surface area and eliminate those thermal breaks.
But you do not want to use so much paste that it actually starts to insulate the plates from each other. You want some metal-to-metal contact (peak to peak).

So that is the trick: you are just filling the holes, not frosting a cake!

I actually did know this, but it's still a great piece of advice. The problem is knowing how much you put on and whether or not it is too much.

Ciara said:

Note: Arctic Silver is a pig to get off your fingers - (Nail Varnish Remover gets it off easy)

Ah, dirty hands don't bother me, and it wears off by the next day

~Lordbob

I have now applied and removed my processors about 10 times now. I have an AMD Phenom so it has screws to tight the H50 down and before that I was using a Zalman air cooler. I do believe that less is more but the other aspect is this thermal paste is thick stuff and if you don't let it settle in and then re-tighten you don't get good dispersion of the paste. When I would remove the cooler I would find only oblong patterns of coverage. This is why I've changed my application from a pea sized drop in the center to the same amount by volume but I make an X shaped pattern. Now when I remove the heatsink the pattern of coverage is much more consistent and wider spread. I'm not a fan of the business card spreader method where you have a thin layer over the entire surface as it wastes a ton of thermal compound but I see if it's done properly and you don't mind the wasteful aspect it does give you total coverage but I still think the X method is working the best for me.

My CPU is on it's way from Newegg. GREAT timing LordBob. Thanks for all the input everyone. Helps me too.

Lordbob75 said:

I actually did know this, but it's still a great piece of advice. The problem is knowing how much you put on and whether or not it is too much.

Ciara said:

Note: Arctic Silver is a pig to get off your fingers - (Nail Varnish Remover gets it off easy)

Ah, dirty hands don't bother me, and it wears off by the next day

~Lordbob

I just apply a small amount (*) and spread it around evenly with my finger on both surfaces, not getting too close to the edges, and discard any excess on a tissue (wasteful, yes, the first few times, then you get the correct amount down pat).
You know you applied too much if there is any squeeze-out.

(*) the size of a lentil. That killed me when I first read it in a post in this forum. Had to go in the kitchen and check to see what size a lentil is. Dog-damn if it wasn't a perfect description!

There was a discussion in another group a while back as to whether the stuff is toxic and whether you should touch it or wear gloves and such, but it was found that typical thermal paste is mostly a silcone caulking with some metallic powder like aluminum or silver in the better stuff, so as long as you don't eat it you are fine. No cheese puffs while assembling the motherboard!

TVeblen said:

as long as you don't eat it you are fine. No cheese puffs while assembling the motherboard!

That cracked me up!

Those would be Cheesy Poofs right that you don't want to eat while working on your rig!

Let's all sing along!
Oh and that was me with the lentil reference as the whole pea thing was getting a bad rape. Don't ever plop down a peas size amount but a pea's worth in diameter yes. Volume wise the best is still the lentil.....any color lentil. Just don't plop down a Yentl that's a whole other issue !

Singin'. Eatin' cheesy puffs. Building the box. Making lentil soup!

The best method is to let the pressure from the heatsink spread the TIM. Using your finger, a credit card etc will never produce an even layer and that leads to tiny air bubbles which decreases heat transfer. The whole point of using thermal compound is to fill all the gaps between the chip and the heatsink. Why use a method that could potentially fail due to air pockets?