How to correctly apply thermal compound to the CPU?

Every now and then I have to work with hardware, be it assembling a new box, or just cleaning it a little bit, and I always have this question: how should I apply the thermal compound to the CPU? When should I have to do it (should I clean it and apply it again for a CPU that already has it)?

Solution 1:

When you have to replace compound on an existing cooler, a common problem is, that the compound ends up sticking the heatsink to the processor, making it difficult to remove the cooler. You could use a hairdryer to heat the heatsink a little, in order to melt the thermal compound and then remove the heatsink moving it slightly in a lateral way. But I wouldn't use the hairdryer too long.

To remove the rest of the old compond, use a cotton swab with isopropyl alcohol. It is alcohol that doesn't contain water. Use a utility knife to eliminate the last rests of the remaining substance, but be careful not to scratch the surface.

It is a common misconception that the more thermal compound is applied, the better. Too much grease can be insulating spoiling the correct heat dissipation, and worse: that grease could end up dropping on motherboard contacts. Normally they don't conduct electricity, but there are compounds with some metal, they will work as conductors, which could lead to a short circuit and destroy your motherboard.

To apply the new compound, again use a cotton swab. Don't put too much of the substance on the processor. You don't necessarily have to cover the whole area of the processor, because the pressure of the cooler will do that for you. How to apply the cooler will depend on the model of processor/cooler you will use. Do it carefully.

Solution 2:

I recently needed to fix a problem with an over-heating machine. I found this video very helpful:

NCIX Tech Tips #11- Installing Thermal Compound

Basically, the steps are:

1. Remove heat sink

2. Use 100% Isopropal alcohol and lint free cleaning rag (microfiber works well) to clean both the CPU and the heat sink

3. Apply a small amount of compound

4. Spread compound evenly

5. Re-attach heat sink

I followed the "grain of rice" method, where you apply a small amount of compound and let the heat sink spread it out for you. So far, so good

Solution 3:

You should always clean off all the old compound before applying new compound. Thinly and evenly would be best - you're smoothing out microscopic scratches in the metal - it's not tile adhesive :)

edit: If you meant "how" as in what with - a razor blade would be perfect.

Solution 4:

Here's a great place to start: Arctic Silver Route to Product Instructions. In general, a little bit goes a long way.