Applying Thermal Paste

[Seth]

There are two major mistakes that are often made when applying thermal paste to a processor:

1) Applying too much.
2) Not applying it correctly.

Many thermal paste "How to" articles will tell you to apply a thin layer of paste across one surface, then mate the processor to the heatsink. This procedure is incorrect as it will allow air pockets (insulators) to remain as the two surfaces come together.

The correct procedure is to apply a small amount (about the size of a BB) on the centre of the processor. Then apply a razor thin coating on the heatsink. As you mate the two, the centre BB portion will thinly spread out from the center outwards, and take out any air along with it.

[mylanta]

There is a third mistake happening more and more lately and that is to use the thermal tape often on heat synchs these days...scrape it off, clean with isopropyl alcohol and use a thin layer of grease as Seth suggests on both cpu and heat synch, and BTW# this is one place where a brand name does make a big difference and I have seen it. I now use Arctic Silver period.

[dbarrow]

Arctic Silver has very specific instructions for use of their product on the web site. It is important to follow them exactly when using AS.

Of course, then there are the tales from the computer repair shops...
Super glue ... best way to hold down a heat sink
Duct tape/ masking tape
Silicon bathroom caulk
Rubber bands

You name it ... people have done it!

BTW: Alcohol wipes may suffice but to really clean off the stubborn stuff like Arctic Silver, auto supply/ carb cleaner or other acetone based solvent. It is important to start with a really clean surface to get the paste to adhere correctly.

[Seth]

Arctic Silver has very specific instructions for use of their product on the web site. It is important to follow them exactly when using AS.

BTW: Alcohol wipes may suffice but to really clean off the stubborn stuff like Arctic Silver, auto supply/ carb cleaner or other acetone based solvent. It is important to start with a really clean surface to get the paste to adhere correctly.

Arctic Silver suggests a tiny amount in the middle, mate the surfaces, then twist the heat sink each way to spread the paste. Problem is, on most motherboards you can't twist the heat sink by any significant amount, as the motherboards components get in the way. So the paste won't get spread out across the entire surface. The method I suggested will cover the entire surface, as well as push any air pockets outward.

BTW: I use 100 % isopropyl alcohol for the cleaning. It also makes for a ravishing drink.

[photolady]

I put a razor thin layer on, and use Denatured Alcohol after using Googone. I haven't tried brake cleaner yet but hear it's good to use. Also, use only Artic Silver 5.

[Seth]

Hi all,

Thanks for your comments.

A couple of things:

1) I've noticed that many cpu temperature readings from the bios or a third party program are simply not accurate (or the sensor isn't). For example, on my bench right now I've got a computer with a pentium 4. Temps show 92 degrees at idle!!! Yet, the heatsink is barely warm. So I quickly pulled off the heatsink and felt the processor, it's barely warm as well. I've encountered this issue on numerous occasions.

2) I've read many internet head to head tests comparing various thermal pastes. The conclusion was that Arctic Silver was no better at cooling than any other silver based paste.

[Pi rules]

For removal, I got some "ArctiClean" by the makers of Arctic Silver. It works wonders with removing thermal compound and makes the surface look like new. I haven't ever tried using anything else. I think it's about $6 for 2 30mL bottles (one to loosen the compound, one to purify the surface) and I would recommend it.

With socket 775 heatsinks (at least the stock; my Thermaltake Blue Orb didn't twist much) it is fairly easy to twist them a little bit.

I've read many internet head to head tests comparing various thermal pastes. The conclusion was that Arctic Silver was no better at cooling than any other silver based paste. Interesting find, could you please provide links?

[Seth]

Interesting find, could you please provide links?

Pi,

I'm a very skeptical person when it comes to just about everything.

When it comes to thermal paste, most techs place Arctic Silver up on a pedestal, yet can provide no empirical evidence to warrant their position.

Under a microscope, the heatsink and cpu surface will look like a mountain range. When those surfaces make contact, the valleys of these "mountain ranges" will trap air pockets. Since air is an insulator, these air pockets will inhibit heat transfer from the cpu to the heatsink.

The purpose of thermal paste is to fill those valleys so air can't enter them. This is where my skepticism kicks in, as any type of paste (including toothpaste) would level those peaks and remove the air. Even more efficient heat transfer can be increased by adding metal particles such as silver to the paste. The following comparisons prove this logical theory.

NOTE: The differences are only two degrees (meaningless). The two degrees is even more meaningless when you factor in a margin of error.

http://www.chillblast.com/reviews/paste.htm

http://www.madshrimps.be/?action=getarticle&number=3&artpage=244&articID=77

http://mod.vault9.net/forums/lofiversion/index.php/t21695.html