Thermal gel is a soft silicone-based thermally conductive gap filler material with high thermal conductivity, low interfacial thermal resistance and good thixotropy. It is an ideal material for applications with large gap tolerances.
Thermal gel inherits the advantages of good affinity, weather resistance, high and low temperature resistance, and good insulation properties of silicone materials. At the same time, it has strong plasticity and can meet the filling of uneven interfaces, and can meet the heat transfer requirements in various applications.
Thermal gel mainly meets the requirements of low stress and high compressive modulus during use, and can realize automatic production; it has good contact with electronic products during assembly, showing low contact thermal resistance and good electrical insulation properties. The cured thermal gel is equivalent to a thermally conductive gasket, with good high temperature resistance and aging resistance, and can work at -40~200℃ for a long time.
The thermal gel is filled between the electronic components to be cooled and the radiator/shell, etc., to make them in close contact, reduce thermal resistance, and quickly and effectively reduce the temperature of electronic components, thereby extending the service life of electronic components and improving their reliability. sex. Thermal gels can be applied by hand or by dispensing equipment.
Types of thermal gels
One-component thermally conductive gel is a paste-like gap-filling thermally conductive material, which is formed with the shape of the structure; it has excellent structural applicability and structural surface adhesion for uneven ceramic, heat sink surfaces or irregular cavities. It has good insulation and pressure resistance characteristics and temperature stability, and is safe and reliable to use; it can flow under pressure like thermal grease and thermal paste; it has high reliability under the action of thermal cycles and will not be used. cured.
Two-component thermal conductive gel is a pre-formed thermal conductive silicone grease product, which mainly meets the needs of low pressure and high compressive modulus when the product is in use. It can realize automatic production, and has good contact with electronic products during assembly, showing a relatively high performance. Low contact thermal resistance and good electrical insulation properties. This material has some advantages of thermal pad and thermal grease at the same time, and better makes up for the weaknesses of both.
Characteristics of thermally conductive gels
- Performance characteristics
Compared with thermal pads, thermal gels are softer and have better surface affinity, and can be compressed to a very low thickness, which significantly improves heat transfer efficiency. The minimum can be compressed to 0.1mm, and the thermal resistance at this time can be 0.08℃·in2/W – 0.3 ℃·in2/W, it can reach the performance of some silicone grease. In addition, the thermal gel has almost no hardness and will not cause internal stress to the device after use.
Thermal gel is easier to handle than thermal grease. The general use of silicone grease is screen or steel plate printing, or direct brushing, which is very unfriendly to users and the environment, and because of its fluidity, it is generally not used for occasions with a thickness of more than 0.2mm.
Thermal gel has a certain degree of adhesion, and there is no problem of oiling and drying out, and it has certain advantages in reliability.
- Advantages of continuous operation
The thermal gel can be directly weighed and used. The commonly used continuous use method is the glue dispenser, which can realize fixed-point quantitative control, save labor and improve production efficiency.
- Curing time
The two-component thermal gel starts from the contact between the A and B glue mixing heads. The viscosity will increase in 5 minutes, and it will dry in 10 minutes. After 30 minutes to 3 hours, the product will gradually harden and become elastic, and the hardness will continue to rise. no longer change.
The cured thermal gel is equivalent to a thermal pad, with good high temperature resistance and aging resistance, and can work at -40~200℃ for a long time.
Unlike adhesives, thermal gels have weak adhesion and cannot be used to fix heat sinks.