Tutorial:  How to apply thermal compound

In the heat of the summer, cooling often becomes a problem.
Many times, an otherwise properly operating machine will freeze during operation in periods of hot weather, or in rooms that lack A/C.

Of all the possible cooling modifications that can be made, often times reapplying thermal compound on processors and graphics card GPU’s can be the easiest, and least expensive thing that you can do.

Compounds and pads are thermally conductive gap fillers.
What this means is that the mating surfaces of the CPU and the heat sink will be brought into complete contact for the fastest and most complete transfer of heat possible.

As the compounds or pads age, cooking in the harsh environment of the CPU contact pad can result in the degradation of the compound or pad.
The drying and shrinking of the compounds and pads result in gaps between the mating surfaces of the processor and the heat sink.

The result  of these conditions is reduced thermal conductivity,  higher CPU temperatures, system instability and, ultimately, damaged components..

Of course, any time the bond of a CPU/GPU/heat sink assembly is broken (due to removal of the heat sink), the compound or pad should be thoroughly removed, surfaces cleaned, and compound reapplied.

First, regarding compounds, I am partial to Arctic Cooling MX-2
There are others, but this stuff is the best performing compound around.
The compound is non-conductive and non-capacitive (electrically), which makes for safe, worry free use.
The high thermal conductivity of the compound, combined with zero hours curing time means that you will get the maximum benefit immediately.

There are thermal pads that are also commercially available, but I feel that the benefits of, and ease of use of MX-2 is worth focusing on this product alone.

With the release of Arctic Cooling MX-3, I have changed to it.
MX-3 shows yet improved performance and is a bit easier to work with than MX-2.
MX-3 also touts a 8 year longevity, which is twice that of other top compounds.

Now, here’s how to reapply compound to a CPU.

Notes of Caution:

Always observe proper anti-static procedures!

Don’t be a Rambo! Be gentle, and handle components in a deliberate, careful manner.

If I have to explain why, then you should stop reading right here.......

Oh, OK. Here’s why:

To ease removal of a heat sink, a machine that is warm will disassemble easier than a stone cold machine.

Be careful to allow the machine to cool enough that you don’t get burned!

And, one last thing-

Keep all solvents and compounds off your skin and out of your eyes!

First thing that must be done, is to shut down your machine and disconnect the cables.

Clear a work space,and open the tower.

For all G4’s prior to the MDD, removing the heat sink is as simple as unclipping the two retainer clips, removing the clips, and lifting off the heat sink.

Most G4 assemblies have an adhesive thermal pad, so a bit of gentle wiggling as you pull straight up may be necessary.

For MDD owners, the heat sink retaining screws must be removed before the heat sink can be lifted off.

Once the heat sink is off, disassembly beyond this point isn’t necessary.
If you prefer to also remove the CPU daughter card, go ahead, but don’t hurt anything.

Now that the parts are separated, you must first clean the mating surfaces.
For heat sinks, removing the old pad is important.
Using a plastic scraper or credit card can ease removal.

For removal of the compound and adhesive residue, a soft cloth is used to wipe the residue off.
If necessary, moisten the cloth with 100% (actually 99.9%) anhydrous Isopropyl alcohol.

This photo shows the thermal pad.
The thermal pad consists of three layers, adhesive/compound, foil, adhesive/compound, which must ALL be completely removed.

Here we can see the foil core and lower layer of adhesive being lifted.

This photo shows the  heat sink after the pad and all residue has been removed.

Note the foil core of the pad in the upper right hand corner.
It has been cleaned and photographed for illustrative purposes only.
It is now garbage.

The heat sink is now ready to go back on the processor.

We must clean the processor contact pad....

Using a soft cloth, gently but firmly wipe the residue off the contact pad.
If necessary, lightly moisten the cloth with 100% Isopropyl alcohol, or commercially available thermal compound removers.

Do not use mineral spirits, lacquer thinner, or solvents that are water borne.
All of these can damage the processor.
Also, 70% Isopropyl alcohol (rubbing alcohol) is 30% water, so should not be used.

Here are the processors that have been cleaned, and are ready to have new compound applied.

Note the compound from previous application, that has oozed under the mylar film.
With MX-2, this isn’t a problem. 
With silver based compounds that are electrically conductive, this excess could short out the processors.
To prevent short, the mylar film must be carefully removed, and the excess cleaned from the processor surface.

Now, I place a dab of new compound on the contact pad of each processor.

Take care to not use too much.
We will test fit, so if there is too much, it may be removed, or, in the case of too little, added before final assembly.

Place the heatsink on the processors. Apply slight pressure, so as to spread the compound across the pad.
Remove the heat sink to inspect.

You can see that the compound is spread evenly across the processors.

Any thin spots will be fine, as long as the corresponding surface of the heat sink has compound stuck to it.

The heat sink can now be placed and fastened for final assembly.

That’s all there is too it.
Try to keep things clean, and don’t use too little or too much thermal compound.

Too cool?
Sunday, August 2, 2009