WHY IS THE COOLING SYSTEM OF MOBILE PHONE MORE AND MORE IMPORTANT?

Why is the cooling system of mobile phone more and more important?

As we all know, the performance of mobile phone processor is improving every year, which inevitably leads to the problem of mobile phone heating. At present, the 5G mobile phones promoted by the mobile phone industry not only increase more antenna reception signals, but also increase the temperature of mobile phones due to high-speed network data transmission. In addition, the mainstream material used in mobile phones is glass. Compared with metal materials, the cooling speed is obviously slower. And the stack of internal components of mobile phones is becoming more and more compact, such as mobile screen, rear video system and mobile phone battery, etc., all of which put forward higher requirements for the heat dissipation capacity of mobile phones. It can be seen from a comprehensive view that the cooling system equipped with mobile phones is the rigid demand of most mobile phones, and it is also the trend of the mobile phone industry.

So, what are the current mainstream mobile phone cooling technologies, and what are the differences? 

At present, heat dissipation technology has become one of the key points affecting the performance of mobile phones. The mainstream mobile phone cooling technology can be divided into the following four types:

1.liquid cooling

Liquid cooling heat dissipation depends on a kind of element called "heat pipe", which is essentially a closed hollow pipe containing liquid. The liquid absorbs heat by evaporation in the evaporation section of the pipeline, and condenses into liquid to release heat from the condensation section of the pipeline.

The common material of the cooling liquid in the liquid cooling heat dissipation of the computer terminal is water. The mobile phone end requires higher requirements than the PC end, and the oil-based material is commonly used as the coolant. The advantages of liquid cooling are long service life and flexible setting. Liquid cooling can be placed in any position inside the mobile phone that needs heat dissipation. At the same time, because the technology is relatively mature, the cost is relatively small.

2.graphite sheet heat dissipation

This is the most common way of heat dissipation, which belongs to the internal heat dissipation form of mobile phones, relying on the high thermal conductivity of graphite. Graphite material has high temperature resistance, good thermal conductivity, and chemical stability and so on, which is currently the most cost-effective cooling material for mobile phones. The characteristics of graphite make it have natural heat dissipation capacity. Its heat dissipation coefficient is 2 ~ 5 times of that of copper, but its density is only 1 / 10 ~ 1 / 4 of that of copper, so it is lighter in weight. At the same time, graphene is easy to process. It can customize the shape and size according to needs. It has good plasticity and shielding electromagnetic wave.

3.VC (vapor chamber) heat dissipation

VC plate, also known as vapor chamber cooling technology, is a vacuum chamber with micro structure on the inner wall, usually made of copper. When heat is transferred from heat source to VC cavity, the cooling liquid in the cavity will start to vaporize after being heated. The liquid vaporizes and absorbs heat. The condensed coolant will return to the heat source in the steam by means of micro structure capillary tube (the driving force of the whole cycle is capillary force), which can be repeated continuously. Vapor chamber is the latest third generation heat dissipation technology, which can be regarded as the upgrading technology of copper tube liquid cooling. Although both of them are gas-liquid phase force, and then return to the internal steam generating source, the difference is: the heat pipe has only effective thermal conductivity in a single direction, while vapor chamber can take the heat away from all directions faster when it is upgraded to the whole surface. The design of vapor chamber varies with the size of different components. The manufacturing process is relatively complex and the production cost is high. It is often used in mobile phone products which need to control the volume and need rapid heat dissipation.