Many users often only pay attention to radiators and fans when purchasing heat dissipation materials, but often ignore a very important thing-heat dissipation silicone grease. In many cases, it is easy to confuse silicone grease and silicone. Although silicone grease and silica gel are only two words literally different, and they are both thermally conductive materials, there is still a big difference in their characteristics. In case of improper use, the consequences can be very serious.

Thermal Grease
Silicone grease is used for lubrication and can be applied under high load. It looks like a large butter, and we generally have less contact. And what we usually call thermally conductive silicone grease should be called silicone paste, the composition is silicone oil + filler. The filler is a finely ground powder, the composition is ZnO/Al2O3/boron nitride/silicon carbide/aluminum powder, etc. Silicone oil ensures a certain degree of fluidity, while the filler fills the tiny gap between the CPU and the radiator to ensure thermal conductivity. However, since silicone oil is low in sensitivity to temperature, it does not become thick at low temperature, it does not become thinner at high temperature, and it is not volatile, so it can be used for a long time. Now some high-end thermal conductive silicone greases use silver powder or aluminum powder as fillers, which take advantage of the high thermal conductivity of metals, but relatively speaking, the metal particles are relatively large, the filling effect is poor, and the performance improvement is not large, and the silicone grease With conductivity, improper use can easily cause short circuits. We generally need to buy thermal grease.

Silicone rubber
The silica gel we are talking about is a kind of silicone rubber, which is a one-component room temperature vulcanized liquid rubber. Once exposed to the air, the silane monomers in it will condense to form a network structure, the system is cross-linked, can not melt and dissolve, is elastic, becomes rubbery, and bonds objects at the same time. Its thermal conductivity is slightly higher than that of ordinary rubber, but it is much lower than that of thermally conductive silicone grease, and once cured, it is difficult to separate the bonded objects. Generally, it can only be used in graphics cards and memory heat sinks. If it is used on the CPU, it will cause overheating, and it is difficult to remove the heat sink. Pulling it out forcefully may directly damage the CPU or the CPU socket. If you pull down the silicone-bonded graphics card heat sink, you may pull the display chip off the PCB.

To sum up, although silicone grease and silica gel are only two words literally different, and they are both thermally conductive materials, they are completely different things. Relatively speaking, the application range of silicone grease is wider, and it is almost suitable for the needs of any heat dissipation conditions; and because silicone is difficult to remove once it is attached, it is mostly used in some occasions where only one-time bonding is required, such as The heat sink of the graphics card, etc.