Definition of silicone rubber electric heating sheet
Thermally conductive silicone sheet is a kind of thermally conductive medium material synthesized by special process with silica gel as the base material and various auxiliary materials such as thermal powder and flame retardant. People in the industry also call it thermally conductive silicone pads, silicone thermal conductive pads, and so on.
Silicone electric heating film
The role of silicone heating pad
1) Thermally conductive silica gel electric heating fins only play a role in heat conduction, forming a good heat conduction path between the heating element and the radiator, and form a heat dissipation module together with the heat sink and structural fixing parts (fan);
2) The main purpose of the thermal conductive silicone sheet is to reduce the contact thermal resistance between the surface of the heat source and the contact surface of the heat sink;
3) The thermal conductive silicone sheet can fill the gap of the contact surface well, and squeeze the air out of the contact surface. Air is a poor conductor of heat, which will seriously hinder the transfer of heat between the contact surfaces; with the supplement of the thermal conductive silicone sheet, you can Make the contact surface better and fully contact, achieve face-to-face contact, and the temperature response can achieve the smallest possible temperature difference.
Advantages and disadvantages of thermal silica film
Advantages of electric heating sheet
1. The material is softer, the compression performance is good, the thermal insulation performance is good, the adjustable range of thickness is relatively large, it is suitable for filling the cavity, the two sides have natural viscosity, and the operability and maintenance are strong;
2. The main purpose of selecting the thermal conductive silicone sheet is to reduce the contact thermal resistance between the surface of the heat source and the contact surface of the heat sink. The thermal conductive silicone sheet can fill the gap of the contact surface well;
3. Since air is a poor conductor of heat, it will seriously hinder the transfer of heat between the contact surfaces, and the installation of a thermally conductive silicone sheet between the heat source and the radiator can squeeze the air out of the contact surface;
4. With the supplement of the thermal conductive silicone sheet, the contact surface between the heat source and the radiator can be fully contacted and face-to-face contact. The temperature response can reach the smallest possible temperature difference;
5. The thermal conductivity of the thermally conductive silicone sheet is adjustable, and the thermal conductivity is more stable;
6. The process gap in the structure of the thermally conductive silicone sheet is bridged, and the process gap requirements of the radiator and the heat dissipation structure are reduced;
7. Thermally conductive silicone sheet has insulating properties (this feature requires appropriate materials to be added in the production);
8. The thermal conductive silicone sheet has the effect of shock absorption and sound absorption;
9. The thermal conductive silicone sheet has the convenience of installation, testing, and reusability.
shortcoming
Compared with thermally conductive silicone grease, thermally conductive silicone has the following disadvantages:
1. Although the thermal conductivity is higher than that of thermally conductive silicone grease, the thermal resistance is also higher than that of thermally conductive silicone;
2. The thermal conductive silicone sheet with a thickness of 0.5mm or less has a complicated process and relatively high thermal resistance;
3. Thermally conductive silicone grease has a wider temperature resistance range, thermally conductive silicone grease: -60°C to 300°C, and thermally conductive silicone sheet: -50°C to 220°C;
4. Price: Thermally conductive silicone grease has been widely used and the price is relatively low. Thermally conductive silicone sheets are mostly used in thin and small electronic products such as notebook computers, and the price is slightly higher.
How to choose thermal silicone sheet
Generally, before choosing a thermally conductive silicone sheet, you should consider the following: electronic product structure, thermal conductivity, size, thickness, thermal resistance, and expected effects.
1. Product structure design selection
In the early stage of the structural design of electronic products, it is necessary to consider the integration of thermally conductive silicone sheets into the design questions. Under different requirements and use environments, the heat dissipation schemes are different, and the optimal heat dissipation scheme should be selected according to the actual situation, and a reasonable heat dissipation structure should be designed. Increase the effect of the thermally conductive silicone sheet.
2. The choice of thermal conductivity of thermally conductive silicone sheet
The choice of thermal conductivity, one depends on the effect you expect to achieve, the other depends on the power consumption of the heat source, and the heat that can be dissipated by the design of the radiator or heat dissipation structure.
According to these requirements, select the thermal conductivity of the thermally conductive silicone sheet. The cost of low thermal conductivity is relatively low, on the contrary, the effect of high thermal conductivity is better, but the cost is also higher.
3. The choice of the thickness of the thermally conductive silicone sheet
This thickness should take into account the heat dissipation scheme used by the electronic product itself. If the heat dissipation structure is selected for heat dissipation, the morphology and structure of the contact surface of the heat dissipation structure should be considered, and the design structure and the thickness of the thermal silicone sheet should be balanced. The choice of thickness is also related to the product's hardness, density, compression ratio and other parameters.
4. Selection of the size of thermally conductive silicone sheet
The size of the thermally conductive silicone sheet can cover the heat source, and the breakdown voltage, electrical resistance, surface resistivity, etc. can meet the conditions.
