What is a thermal pad?

Thermally conductive gaskets are high-performance gap-filling thermally conductive materials, which are mainly used for the transfer interface between electronic devices and heat sinks or product shells; traditionally used thermally conductive materials are mostly metals, such as Ag, Cu, Al, and metal oxides, such as Al2O3, MgO, BeO and other non-metallic materials, such as graphite, carbon black, etc.; but with the development of industry and science and technology, people put forward new requirements for thermal conductivity materials, hoping that the materials have excellent comprehensive properties.

In the electrical and electronic fields, due to the rapid development of integration technology and assembly technology, the volume of electronic components and logic circuits has shrunk thousands of times. Insulating materials with higher thermal conductivity are needed to solve the heat dissipation problem. In recent decades, the application fields of polymer materials have been continuously expanded. The use of synthetic polymer materials to replace metal materials used in traditional industries has become one of the directions of world scientific research efforts, and thermally conductive gaskets have emerged.

What material is the thermal pad made of

The thermal pad is based on silica gel, added with a certain amount of metal oxide and various thermal conductive materials, and then synthesized the thermal pad through a special process. The thermal pad is a polymer composite thermal conductive material that uses silicone resin as the bonding base material and is filled with thermal powder to achieve the purpose of heat conduction.

Material of base material for thermal pad

1. Insulating thermal conductive material powder: organic silicon plasticizers such as magnesium oxide, aluminum oxide, boron nitride, beryllium oxide, aluminum nitride, quartz, etc.

2. Flame retardant: magnesium hydroxide, aluminum hydroxide

3. Inorganic coloring agent (used to fill the product with a specific color)

4. Cross-linking agent (to make the product slightly sticky)

5. Catalyst (requirements for process shaping)

Note: The thermal pad plays a role in heat conduction, forming a good thermal path between the heating element and the heat sink and can fill the gap.

Composition of thermal pad filler

1. Metal powder filler: copper powder, aluminum powder, iron powder, tin powder, nickel powder, etc.;

2. Metal oxides: aluminum oxide, bismuth oxide, beryllium oxide, magnesium oxide, zinc oxide;

3. Metal nitrides: aluminum nitride, boron nitride, silicon nitride;

4. Inorganic non-metals: graphite, silicon carbide, carbon fiber, carbon nanotube, graphene, beryllium carbide, etc.

Process principle

The thermal conductivity of the thermal pad depends on the interaction between the polymer and the thermally conductive filler. Different types of fillers have different thermal conduction mechanisms.

The heat conduction mechanism of the metal filler, the heat conduction of the metal filler mainly depends on the movement of electrons, and the corresponding heat is transferred during the movement of the electrons;

The heat conduction mechanism of non-metallic fillers. The heat conduction of non-metallic fillers mainly depends on the heat conduction of phonons, and the thermal energy diffusion rate mainly depends on the vibration of adjacent atoms. Including metal oxides, carbides and nitrides.

With the advent of the 5G era, electronic products are developing towards functional integration. There are more and more components on circuit boards, and the power of electronic products is increasing. The requirements for the thermal conductivity of thermal pads are getting higher and higher. At the same time, 5G gradually For commercial applications, thermally conductive gaskets also have broader development prospects. This requires related thermal pad manufacturers to continuously develop better thermal pad materials.