There a million different pages around the Internet with conflicting information on how much thermal paste to apply and how to spread it. Some say a half-bean-sized drop in the middle, others say a circle or rectangle on the CPU. Some tell you to let the heatsink's base spread it, while others say to spread it with a knife or your finger with a plastic bag on it. Some coolers even come it with applied fully on the base, like Corsair H50 and all Arctic Cooling products.

What is the best way to apply and spread thermal paste, and how much of it?


You should use the absolute minimum - just enough to ensure that any micro-pits in the heatsink and CPU top are filled. I spread it like (very thin) butter using the end of a plastic ruler and then give the heatsink a gentle slide a few mm in every direction once it is in place and before I clamp it down.

Protip 1: Avoid using toothpaste!

Protip 2: Regardless of how careful you are, the damn stuff gets everywhere and is not water soluble so don't wear your favourite top or trousers/pants when using the stuff and don't do the work on that valuable, antique black lace table covering.

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    And you don't want to use too much either. That's equally important. – user3463 Feb 16 '11 at 7:45
  • +1, almost exactly what I do, an old credit card or similar is perfect for making a flat layer that covers the die. – Sirex Feb 16 '11 at 8:30
  • On the other hand with a flat layer, you can get air bubbles between heatsink and processor. Some people fix this by putting a small blob of thermal paste on the middle of the flat layer, at the intersection of the diagonals, so that it comes in contact with the heatsink first and prevents bubble creation. Another option, if there is enough thermal paste available, it to try several methods of application and carefully remove the heatsink after. If there are undisturbed areas of paste, that's where the bubbles were. – AndrejaKo Feb 16 '11 at 10:47

That depends on the paste you are using. I use a non-conducting colloidal silver paste and apply just a small, grain of rice sized, dab in the middle and spread it out with a plastic bag protected finger. The surface of the die has to be immaculate as in cleaned with acetone first.

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    By "depends", , What are some examples whereby the amount might differ? – Pacerier Jun 18 '15 at 13:51

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