Heat sinks are a device which is used to dissipate heat of electronic elements in electrical appliances. There are many kinds of heat sink materials. The following describes are about the aluminum, copper and combinative radiation fins of copper and aluminum.
(1)Aluminum heat sink
Currently, heat sink of aluminum is one of
heat sinks of the highest use rate. As the highest amount of metal in the earth's crust, the main characteristics are low cost and low thermal capacity. Although the endothermic speed is very slow, the exothermic speed is fast. The effect of heat dissipation is proportion to its structure and work. If the number of
heat sinks is more and the bottom polishing is better, the heat radiating effect will be better. However, it is also restricted by the manufacturing process because using manufacturing technology of extrusion aluminum, the minimum interval of radiator groove is only 1.1mm. The heat dissipation principle of aluminum heat sink is very simple: By using cooling fins to increasing the contact area with air and then using fans to accelerate the air flow, the heat from the fins will be taken away. The price of the heat sink is low. But compared with the following heat sinks, the cooling effect is very bad.
(2)Copper heat sink
The material of heat sink is copper, which is the only difference with aluminum heat sink. The heat conduction efficiency of copper is 412w/mk, which is twice more than aluminum’s. But copper heat capacity is so high that the heat sink absorbs heat fast and release heat slowly. To achieve the ideal cooling effect, high power and high speed fans are needed. As the copper has good toughness and its manufacturing process is easier than aluminum, heat sink precision can be made higher and radiating area is correspondingly greater than the aluminum. All of these can make up for deficiency of heat slowly caused by its high heat capacity. Overall, its heat dissipation effect is much better than the aluminum but the cost is very high.
(3)Aluminum heat sink inlaid with copper
Aluminum heat sink inlaid with copper use advantages of copper and aluminum. In touch with copper, the heat of the CPU is dissipated by using the characteristic of fast heat absorption of copper. And using fast exothermic characteristic of aluminum, the heat of copper is released. The radiating effect is better than the method of single pure copper or pure aluminum fins. However the drawback is that copper and aluminum can’t do 100% contact, the heat conduction efficiency will be affected to a certain extent.
