How the heat sink is produced
The heat sink is a device for dissipating heat from electronic components that are easy to heat in electrical appliances. They are mostly made of aluminum alloy, brass or bronze in plate, sheet, and multi-sheet shapes.
For example, the CPU central processing unit in the computer needs to be quite large. The heat sink, the power tube in the TV, the line tube, and the power amplifier tube in the power amplifier must use the heat sink.
Generally, the heat sink should be coated with a layer of thermally conductive silicone grease on the contact surface of the electronic components and the heat sink during use, so that the heat emitted by the components can be more effectively transferred to the heat sink, and then radiated to the surrounding air through the heat sink. As far as the heat sink material is concerned, the thermal conductivity of each material is different. They are arranged from high to low in terms of thermal conductivity. They are silver, copper, aluminum, and steel. However, it would be too expensive to use silver as a heat sink, so the best solution is to use copper. Although aluminum is much cheaper to absorb heat, it is obviously not as good as copper in thermal conductivity (only about 50% of copper).
At present, the commonly used heat sink materials are copper and aluminum alloy, both of which have their own advantages and disadvantages. Copper has good thermal conductivity, but it is more expensive, difficult to process, too heavy (many pure copper radiators exceed the weight limit of the CPU), small heat capacity, and easy to oxidize. The pure aluminum is too soft to be used directly. The aluminum alloy used can provide sufficient hardness. The advantages of aluminum alloy are low price and light weight, but the thermal conductivity is much worse than that of copper. Some radiators take their own strengths and embed a copper plate on the base of the aluminum alloy radiator. For ordinary users, the use of aluminum heat sinks is sufficient to meet the heat dissipation requirements. The radiator for heating in winter in the north is also called a heat sink. The heat sink occupies an important role in the composition of the heat sink. In addition to the active heat dissipation of the fan, evaluating the quality of a heat sink largely depends on the heat absorption capacity and heat conduction capacity of the heat sink itself.
1. Aluminum extruded heat sink aluminum material has been used in the radiator market because of its softness and easy processing. The aluminum extrusion technology simply means that after the aluminum ingot is heated at high temperature, the aluminum liquid flows through the grooves under high pressure. The extruded mold is used to make the preliminary heat sink, and then the preliminary heat sink is cut and grooved to make the common heat sink. The cost of aluminum extruded heat sink is low, and the technical threshold is not high. However, due to the limitation of its own material, the ratio of the thickness and length of the heat dissipation fin cannot exceed 1:18, so it is difficult to increase the heat dissipation area in a limited space. The aluminum extruded heat sink has a poor heat dissipation effect, and it is difficult to handle the high-frequency CPU that is rising today.
2. Copper plug type heat sink The main materials used for the mainstream heat sink on the market are nothing more than aluminum and copper. The plug copper process is a product that combines the advantages of aluminum and copper. The copper plugging process is completed by using the principle of thermal expansion and contraction. After heating the aluminum extruded heat sink, the copper core is inserted into it, and finally the overall cooling is performed. Since no third-party medium is used, the copper plug process can greatly reduce the thermal resistance between the contact surfaces, which not only ensures the tightness of the copper-aluminum bonding, but also makes full use of the characteristics of fast heat dissipation of aluminum and fast heat absorption of copper. This kind of copper plug process has a moderate cost and good heat dissipation effect, and it is currently the mainstream type of heat sink on the market.
3. Compared with the aluminum extruded heat sink, the cutting process solves the limitation of the fin thickness to length ratio of the heat sink. The cutting process is to use a special tool to cut the whole material into layers of fins. The heat dissipation fins can be as thin as 0.5mm, and the fins and the base of the heat sink are integrated, so there will be no interface impedance. The problem. However, in the production process of this cutting process, the cost is high due to the large amount of waste and the low yield rate. Therefore, the cutting process is mainly biased towards copper heat sinks.
The basic production process of heat sink: product requirements---drawing development---mold making---die trial (extruded aluminum profile)---cutting, CNC processing---functional size sample confirmation---color confirmation ( Anodizing or oxidation\spraying\other) --- production input --- packaging (inspection) --- delivery.
