1. What are the characteristics of thermal silica gel (thermal potting glue)?
Thermally conductive silicone is usually also called thermally conductive potting glue or thermally conductive RTV glue. It is a low-viscosity flame-retardant two-component addition type silicone heat-conducting potting glue. It can be cured at room temperature or heated. The higher the temperature, the faster the cure. specialty. The biggest difference from thermal silicone grease is that thermal silicone can be cured and has certain adhesive properties.
Thermally conductive silica gel (thermally conductive potting glue) is a kind of silicone rubber, which belongs to the liquid rubber of one-component room temperature vulcanization. Once exposed to the air, the silane monomers in it condense to form a network structure, the system is cross-linked, cannot be melted and dissolved, is elastic, becomes rubbery, and adheres to objects at the same time. Its thermal conductivity is slightly higher than that of ordinary rubber, but it is much lower than that of thermal conductive silicone grease, and once cured, it is difficult to separate the bonded objects.
2. What are the characteristics of thermal grease
Thermally conductive silicone grease is usually also called “thermally conductive paste”, “silicon paste”, thermally conductive silicone grease is a kind of high thermal conductivity insulating silicone material, it does not cure, and can maintain the state of grease for a long time at the temperature of -50°C-+230°C thermally conductive material. It not only has excellent electrical insulation, but also has excellent thermal conductivity, and at the same time has low oil separation (tends to zero), high and low temperature resistance, water resistance, ozone resistance, and weather aging resistance.
It can be widely applied to various electronic products, and the contact surface between heating elements (power tubes, silicon controlled rectifiers, electric heating stacks, etc.) The role of heat transfer medium and moisture-proof, dust-proof, corrosion-proof, shock-proof and other properties.
It is suitable for surface coating or overall potting of various microwave devices such as microwave communication, microwave transmission equipment, microwave special power supply, and voltage stabilized power supply. This type of silicon material provides excellent thermal conductivity for electronic components that generate heat. Such as: transistors, CPU assembly, thermistors, temperature sensors, automotive electronic components, car refrigerators, power modules, printer heads, etc.
3. The similarities and differences between thermal silica gel and thermal grease
What they have in common: they all have thermal conductivity and insulation, and they are all thermal interface materials.
the difference:
Thermally conductive silicone (thermally conductive potting glue): sticky (once stuck, difficult to remove,
Therefore, it is mostly used in occasions where only one-time bonding is required. It is translucent, dissolves at high temperature (viscous liquid), solidifies (exposed) at low temperature, cannot melt and dissolve, and is elastic.
Thermally conductive silicone grease (thermally conductive paste): Adsorptive, non-sticky, paste semi-liquid, non-volatile, non-curing (does not thicken at low temperature, and does not become thinner at high temperature).
4. Application scope
Compared with silica gel, the application of silicone grease is more extensive. Many industrial and electronic products use thermal conductive silicone grease where heat dissipation is required.
Moreover, there are many types of silicone grease, and people add some “impurities” to pure thermal conductive silicone grease to improve its thermal conductivity.
These impurities are graphite powder, aluminum powder, copper powder and so on.
Pure silicone grease is pure milky white, the silicone grease mixed with graphite is dark in color, the silicone grease mixed with aluminum powder is grayish and shiny, and the silicone grease mixed with copper powder is somewhat yellowish.
Post time: Jan-16-2023