To learn how to apply thermal grease, you need only two things: a little free time and an Internet connection. There are many articles on this topic on the global Web. They are written by everyone who is not lazy - from venerable computer gurus to beginners who want to assert themselves in this way.
Moreover, the question of how to apply thermal grease is nothing complicated. Even with insufficient accuracy, nothing terrible will happen. Except that the temperatures will be higher than they could be. Although, of course, if you spread such a paste on the motherboard as butter on the bread, then nothing good will come of it. Speaking of sloppiness, we mean reasonable limits.
In most articles on how to apply thermal grease, only computer components are indicated. In fact, the scope of this viscous substance is not limited only to computer technology. Among the elements of electronic circuits there are several that are significantly heated during operation. The heating level is so great that without the use of a relatively massive heat-dissipating radiator, they very quickly fail. These are some transistors, semiconductor diodes, integrated circuits.
Obviously, the denser the surfaces of the radiator and the cooled element are in contact, the more efficient is the heat sink.
It follows that to increase the efficiency of heat dissipation it is necessary to eliminate all defects in surface treatment: they must be perfectly even, parallel, and the vector of the pressing force would be an exact perpendicular. However, instead of performing such meticulous work in production, a different solution is used. A viscous mass is applied between the surfaces, which compensates for processing defects due to fluidity. In fact, we are talking about an intermediate thermal interface with a high coefficient of thermal conductivity. The best thermal grease should have the following properties:
- transfer heat no worse than the material of the radiator;
- be liquid, but not spread out;
- have the ability to "stick" to surfaces.
It is easy to understand that manufacturers of thermal grease compromise, trying to combine the opposite properties in the product. Very often, the composition of the pastes is kept secret, so it is difficult to verify the statements of manufacturers. For example, Zalman thermal paste, in which
zinc oxide is the basis
, dissipates 1.2 W / m * K, but the Soviet KPT-8 is only 0.7 units. However, knowing how to apply thermal grease correctly, it is possible to achieve quite acceptable heat sink efficiency.
To do this, thoroughly clean the surfaces of the remnants of the previous thermal interface. Dense, fleecy fabric is perfect. Then it is necessary to apply a paste evenly on the surface of the heating element with a thin layer. There should not be blank areas, but surpluses will only worsen heat transfer (after all, even the best thermal grease conducts heat worse than metal). After that, you need to carefully connect the surfaces and fix them with a clamping system. At the same time, distortions are unacceptable, since they reduce the area of contact and reduce efficiency.