Introduction to the characteristics and working principle of phase change thermally conductive materials
We know that matter exists in three forms: solid, liquid and gaseous. The transformation of matter from one physical form to another is called a phase transition. The process of absorbing or releasing energy by using the phase change of matter is the phase change energy storage. The phase transition process is generally an isothermal or nearly isothermal process, and is often accompanied by the absorption and release of a large amount of energy, which makes it used in the heat conduction and heat dissipation scheme of electronic components.
In recent years, many thermal conductive materials have emerged at home and abroad for heat dissipation of electronic components. For example, liquid thermal conductive silicone grease is used on IGBTs. Although the heat dissipation effect is good, the operation is inconvenient, the application is uneven, and it is easy to dry up. The emergence of thermally conductive phase change materials fills this gap.
What is a thermally conductive phase change material?
Thermally conductive phase change materials are thermally conductive interface materials that can change from solid to liquid above a certain formula design temperature, also known as phase-change thermally conductive materials in the industry; thermally conductive phase-change materials are heat-enhancing polymers designed to reduce power consumption The thermal resistance between the electronic device and the heat sink connected to it is minimized, and this low thermal resistance channel maximizes the performance of the heat sink.
Characteristics of thermally conductive phase change materials:
- Strong interface wetting ability;
- Above the phase transition temperature, the gap between the interfaces can be greatly filled;
- Using pressure, the coating thickness of the material between the interfaces can be extremely reduced;
- Very effectively remove the air between the interfaces.
The working principle of thermally conductive phase change materials:
- At room temperature, the thermally conductive phase change material remains solid, and the air in the interface cannot be excluded;
- As the temperature increases, the phase change thermally conductive material becomes softer and softer, the air at the interface begins to be expelled, and the temperature begins to drop;
- When the phase-change thermally conductive material reaches the phase-change temperature, the phase-change thermally conductive material becomes liquid, which can greatly wet the interface, exhaust the air in the interface, reduce the thermal resistance of the interface, and transmit the heat as much as possible; In the operating state, the phase change thermally conductive material becomes solid again, but maintains 100% complete wetting of the interface.