What is the difference between thermal gel and thermal grease?
[ Date: 2020-12-21 10:47:55 Author: Popularity: ]
Share :    67.7K

1. What are the characteristics of thermal gel (thermal conductive potting adhesive)?

Thermal gel, also known as thermal conductive potting adhesive or thermal conductive RTV adhesive, is a low viscosity flame retardant two component addition silicone thermal conductive potting adhesive, which can be solidified at room temperature or can be heated and solidified. The higher the temperature is, the faster the curing speeds is. The biggest difference between thermal grease and thermal gel is that it can solidify and have certain adhesive property. Thermal gel (thermal conductive potting adhesive) is a kind of silicone rubber which belongs to one component vulcanized liquid rubber at room temperature. Once exposed to the air, the silane monomer will condense and form a network structure. The system is cross-linked, unable to melt and dissolve. It is elastic and can form a rubber colloidal state. At the same time, it adheres to the object. Its thermal conductivity is slightly higher than that of ordinary rubber, but it is much lower than that of thermal grease, and once cured, it is difficult to separate the bonded objects.


 2. What are the characteristics of thermal grease?

Silicone grease is a kind of  high thermal conductivity insulating silicone material, also called thermal paste, not curing, which can be used at  50 to + 230 and keep the cream condition for a long time. It has not only excellent electrical insulation, but also excellent thermal conductivity, low oil dissociation (tends to zero), high and low temperature resistance, water resistance, ozone resistance, weather aging resistance. It can be widely applied to the contact surface between the heating body (power tube, silicon controlled rectifier, electric heating stack, etc.) and the heat dissipation facilities (heat sink, heat dissipation strip, shell, etc.) in various electronic products and electrical equipment, playing the role of heat transfer medium and the performance of moisture-proof, dust-proof, anti-corrosion, shockproof, etc. It is suitable for surface coating or whole encapsulation of microwave devices, such as microwave communication, microwave transmission equipment, microwave power supply, stabilized voltage power supply and other microwave devices. This kind of silicon material provides excellent heat conduction effect for heat generating electronic components. Such as transistor, CPU assembly, thermistor, temperature sensor, automotive electronic parts, car refrigerator, power module, printer head, etc.

 3. The similarities and differences between heat conducting gel and thermal conductive silicone grease

Common point: both of them have thermal conductivity and insulation, and they are thermal conductive interface materials.


Thermal conductive gel (thermal conductive potting adhesive): sticky (once sticky is difficult to remove, so most of the time is used in occasions that only need one-off bonding, translucency, high temperature dissolve (viscous liquid), solidification (exposure) at low temperature, cannot melt and dissolve, and elastic.

Thermal conductive silicone grease (thermal paste): adsorption, no viscosity, paste like semi liquid, non volatile, non curing (no thickening at low temperature, no thinning at high temperature).


4. Scope of application

Compared with silica gel, silicone grease is widely used in many industrial and electronic products where heat dissipation is needed. In addition, there are many kinds of silicone grease. People add some "impurities" to pure thermal conductive silicone grease to improve its thermal conductivity. These impurities are graphite powder, aluminum powder, and copper powder and so on. The pure silicone grease is pure milky white. The color of the silicone grease doped with graphite is dark, some of the silicone grease doped with aluminum powder is gray and shiny, and the silicone grease doped with copper powder is some yellowing.