What is the difference between thermal grease and thermal pads?

The difference between thermal grease and thermal pads lies in the fact that the application field of the product needs to be analyzed from various aspects such as thermal conductivity, product structure, and safety requirements for product performance, and the conclusion is completely different. Therefore, the detailed explanation of the thermal conductivity, product application, and price cost of the two products will be given from different consideration points.

If we only consider the heat dissipation and heat conduction of products, of course, thermal grease is better. Because thermal grease is a paste-like liquid, just a thin layer of thermal grease can be applied easily, so the thermal resistance is very low. In addition, the wetting performance of thermal grease can fully squeeze out the air and improve its own thermal conductivity. On the other hand, thermal pads are more difficult to achieve this low thermal resistance effect. Generally speaking, the limit of thermal pads is only 0.2mm thickness, but considering the mechanical properties of such thin pads, fiberglass reinforcement is often added to thin products, which will increase the thermal resistance again. Therefore, from the perspective of product heat dissipation and heat conduction, it is obvious that thermal grease is better than thermal pad.

In terms of ease of operation for thermal conductive materials alone, it is the thermal pad that has the advantage. Because thermal grease itself is difficult to apply evenly when applied. And the viscosity directly affects the operability; after a long time of use, thermal grease will appear to leak oil, which will contaminate the components and may cause short circuit failure. At the same time, it will appear dry and cracked. However, the thermal pad can be made into irregular sheet materials according to the various structural needs of the product, and it is already fairly even. It can be attached and used. It also has a certain strength and elasticity.

In terms of price, thermal grease is more advantageous than thermal pad. However, due to the complexity of production operations and the difficulty of obtaining fireproof certification for the product, these factors should also be considered when choosing thermal conductive materials.  

Thermal grease is now widely used in electronics, electrical appliances, and semiconductor devices for heat dissipation, filling or coating, to guide out the heat generated by the components. Such as filling the gap between the CPU and the heat sink, filling the gap between high-power transistors, thyristors, diodes and the substrate (aluminum or copper), filling the gap between the TV power amplifier tube and the heat sink, and filling the gap between the semiconductor cooling device. It reduces the working temperature of heat-generating components.  

Thermal pads are divided into ordinary thermal pads, strong adhesive thermal pads, thermal  pads with a silicone backing, thermal pads with glass fiber in the middle, etc., according to the product characteristics of different applications. They are widely used in the LED industry, power supply industry, communication industry, automotive electronics industry, PDP / LED TV applications, household appliance industry, etc.