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What is a heat sink

2021-10-25  734

1. What is a heat sink

Heat sink is a device for radiating easily heated electronic components in electrical appliances. It is mostly made of aluminum alloy, brass or bronze in plate shape, sheet shape, multi sheet shape, etc. for example, a considerable heat sink should be used for CPU in computer, and a heat sink should be used for power tube, line tube and power amplifier tube in TV. Generally, during the use of the heat sink, a layer of thermal conductive silicone grease shall be coated on the contact surface between the electronic components and the heat sink, so that the heat emitted by the components can be more effectively transmitted to the heat sink, and then distributed to the surrounding air through the heat sink.

2. Working principle of heat sink

The principle of heat dissipation of heat sink is to increase the surface area and speed up heat dissipation. As the material of the heat sink, it is a metal with smaller specific heat. It absorbs heat quickly and loses heat relatively quickly. In this way, it plays the effect of rapid heat dissipation through heat transfer.

For example, the CPU and CPU in the computer should use a considerable heat sink, and the power tube, line tube and power amplifier tube in the TV should use a heat sink.

Generally, during the use of the heat sink, a layer of thermal conductive silicone grease shall be coated on the contact surface between the electronic components and the heat sink, so that the heat emitted by the components can be more effectively transmitted to the heat sink, and then distributed to the surrounding air through the heat sink.

As for the material of heat sink, the thermal conductivity of each material is different. According to the thermal conductivity from high to low, they are silver, copper, aluminum and steel. However, if silver is used as heat sink, it will be too expensive, so the best solution is to use copper. Although aluminum is much cheaper, it is obviously not as thermally conductive as copper (only 50% of copper).

3. Type of heat sink

Make the heat emitted by components conduct more effectively

b. Copper heat sink

c. Copper aluminum combined heat sink

d. Heat pipe heat sink

e. Iron heat sink

f. Graphite heat sink

g. Aluminum profile heat sink

h. Aluminum plate heat sink

4. Function of heat sink

Radiator is a device to accelerate the heat dissipation of heating body. There are two points to measure the quality of a radiator: heat dissipation and silence.

Integrated circuits are widely used in computer components. As we all know, high temperature is the enemy of integrated circuits. High temperature will not only lead to unstable operation of the system, shorten the service life, and even burn some parts. The heat that causes high temperature does not come from outside the computer, but from inside the computer, or integrated circuit. The function of the radiator is to absorb these heat and then radiate it to the inside or outside of the chassis to ensure the normal temperature of computer components. Most radiators absorb heat by contacting with the surface of heating parts, and then transfer the heat to a distance through various methods, such as the air in the chassis, and then the chassis transmits the hot air to the outside of the chassis to complete the heat dissipation of the computer. The radiator is not immune to dust. Due to the wind flow, the wind pressure generated by the radiator fins is not vertical downward pressure, but annular diffusion. This is just like the ceiling fan on the roof. The wind flow directly below the fan is often not as strong as the periphery of the ceiling fan, and the dust in the air will circulate around the periphery with the wind speed and adhere to the cooling fins around the fan, resulting in no wind flow, At the same time, the return air generated by the blockage of fins will involve a large amount of dust into the fan blades, reducing the service life of the radiator; The water vapor in the air adheres to the fan blade, causing dust to adhere to the fan blade, increasing the weight of the blade and reducing the speed; The radiator bearing rotates at high speed. With the passage of service time, oily substances overflow the bearing, adhere to the radiator and accumulate more dust