Thermal pads are thermally conductive media that fills the air gap between the heating element and the heat sink or metal casing of electronic products. The flexible and elastic characteristics of thermal pads enable them to be used to cover very uneven surfaces. Heat is conducted from the entire PCB to the metal housing or diffuser plate, increasing the efficiency and longevity of heat-generating electronic components.
In the use of thermal pads, pressure and temperature are mutually restricted. With the increase of temperature, after the equipment runs for a period of time, the thermal pad material will soften, creep and stress relaxation, and the mechanical strength will also be reduced. down, the pressure of the seal decreases.
Characteristics of Thermal Gaskets
- The material is soft, the compression performance is good, the thermal conductivity and insulation performance are good, and the thickness can be adjusted in a relatively large range, suitable for filling the cavity, with natural viscosity on both sides, and strong operability and maintainability;
- The main purpose of selecting the thermal pad is to reduce the contact thermal resistance between the surface of the heat source and the contact surface of the heat sink, and the thermal pad can fill the gap between the contact surfaces well;
- Since air is a poor conductor of heat, it will seriously hinder the transfer of heat between the contact surfaces, and installing a thermal pad between the heat source and the radiator can squeeze the air out of the contact surface;
- With the addition of thermal pads, the contact surface between the heat source and the radiator can be better and fully contacted, and the face-to-face contact can be truly achieved, and the temperature response can reach as small a temperature difference as possible;
- The thermal conductivity of the thermal pad is adjustable, and the thermal conductivity is better;
- The process tolerance of the thermal pad in the structure is bridged, and the process tolerance requirements of the radiator and the heat dissipation structural parts are reduced;
- The thermally conductive gasket has insulating properties (this feature needs to be added with suitable materials during production);
- The thermal conductive gasket has the effect of shock absorption and sound absorption;
- The thermal conductive gasket has the convenience of installation, testing and reusability.
How to use thermal pads
- Keep the surface of the thermal pad clean to prevent the thermal pads from sticking to dirt, and the self-adhesion and sealing thermal conductivity of the dirty thermal pads will deteriorate;
- When taking the thermal pad, the thermal pad with a large area should be grasped from the center, and the grasp of the sheet with a small area is not required, because the uneven force of the large thermal pad will cause deformation and affect the follow-up operation, or even damage the thermal pad;
- Hold the sheet in the left hand, and tear off one side of the release protective film with the right hand. The protective film on both sides cannot be torn off at the same time to reduce the number and area of direct contact with the thermal pad;
- Tear off one side of the protective film, facing the radiator, first align the thermal pad to the radiator; when slowly lowering the thermal pad, be careful to avoid the generation of air bubbles;
- If bubbles are generated during the operation, you can pull up one end of the thermal pad and repeat the above steps, or use tools to gently wipe the bubbles, but the force is not too large;
- Tear off the other protective film, put it into the radiator, and tear off the last protective film with less force to avoid straining or pulling up the thermal pad;
- After tightening or using a strong adhesive thermal pad, apply a certain pressure to the radiator and store it for a period of time to ensure that the thermal pad is fixed.
Of course, the correct selection of thermal pad is the key to ensuring high heat dissipation of the equipment. For the same product, there are generally multiple specifications of thermal conductivity thermal pads to choose from. When choosing the thermal pad solution, it is necessary to select the thermal pad reasonably according to the physical properties, pressure, temperature and size of the equipment, operating conditions, and the length of the continuous operation cycle, and make full use of the advantages and disadvantages of the thermal pad. .