Heat sink fins machine you don't know about the manufacturing process of heat sink

The effect of an air-cooled heat dissipation product depends not only on the air volume of the fan, but also on the design of heat sink fins machine. A properly designed heat sink can make the computer run stably only by relying on the chassis fan under the condition of non overclocking and non continuous full load. It can be seen that the importance of heat sink, and the heat dissipation effect of heat sink is inseparable from its manufacturing process.

Nowadays, the manufacturing process of heat sink includes cutting, extrusion, stamping, die casting and other technologies as the core, and more than a dozen specific manufacturing processes have been developed. Their advantages and disadvantages are obvious, and there are details that can be distinguished. In the following article, Xiaobian will come together for you to let you know well when choosing cooling products.

1. Cutting and aluminum extrusion

Strictly speaking, cutting is the abbreviation of a large class of manufacturing processes, such as high-speed cutting and laser cutting. However, they have one thing in common is that machine tools such as turning, drilling, milling and grinding need to use cutting processes in order to obtain some special and fine shapes in the forming process of heat sink. It is mainly used for plate forming (formation of bottom surface and fins), radiator slotting, carving of special lines, etc.

Cutting technology

The base of the radiator is obviously made by cutting technology. The plane, edges and corners and the logo of some manufacturers are processed by cutting technology. The advantage of the cutting process is that it is widely used, but the disadvantage is the equipment, mainly the tool wear is fast, most of which need manual participation or automatic control, and the cost is high.

Aluminum extrusion is to heat the aluminum alloy ingot to about 520 ~ 540 ℃, use mechanical pressure to make the aluminum liquid flow through the extrusion die made of die steel, cool the aluminum liquid at the die outlet, make it solidify rapidly, and become the primary embryo of heat sink with continuous parallel structure, and then cut the primary embryo to see our common heat sink.

Heat sink you don't know   Uncover the manufacturing process of heat sink

Aluminum extrusion heat dissipation process

The commonly used aluminum material in this way is aa6063, which has good thermal conductivity (about 160-180w / m * k) and processability. However, it is precisely because of the shortcomings of this material that the ratio of fin thickness to length is limited to no more than 1:18. Therefore, although the products produced in this way are "30 yuan standard configuration", they are not competent for the heat dissipation of the current processor, so try not to choose such products when purchasing.

2. Precision cutting and aluminum die casting

It has to be said that this is a landmark metal forming process. The definition of precision cutting is to cut a whole metal profile with a special planer to a specified thickness according to the needs, and then bend it upward to an upright state to become a heat dissipation fin. In fact, a simpler way to understand is to cut a whole piece of metal into the shape of heat sink we usually see. This method is most common on pure copper fins.

Precision cutting increases product cost

The advantages of precision cutting are that the heat absorbing bottom is integrated with the fins, the connection area (connection proportion) is large, there is no interface impedance, and the fins are thick, which can make more effective use of the heat dissipation surface area; In addition, the cut fins are densely arranged, which can obtain a larger heat dissipation area per unit volume. However, this method is affected by raw materials and so on, and the yield is low; The ratio of lean to length is insufficient; The distance between sheets is short, the wind passage space is small, and the wind resistance is large. And the production equipment and production cost are very high. This method is not very common now, but many blade servers use this specification of heat sink.

Aluminum die casting is a widely used single aluminum alloy processing technology. After melting the aluminum alloy ingot into liquid, fill it into the model, use the die-casting machine for one-time die-casting, and then make the monomer heat sink after cooling and subsequent treatment.

Common use of aluminum die casting fan

Advantages of aluminum die casting: integrated forming, no interface impedance; Thin, dense or complex fins can be manufactured, which is easy to realize some special designs. Its obvious disadvantages: the mechanical properties and thermal conductivity of the material can not be complete; Excessive surface flow lines and oxide slag during die casting will reduce the heat conduction effect; When cooling, the internal micro pores are high and the real thermal conductivity decreases; The service life of the die is short, the equipment is relatively complex, the output is small and the cost is slightly high. In fact, most of the aluminum heat sinks of this process have good heat dissipation effect. In the past, the products manufactured have a certain cost performance.

3. Folding and welding are the mainstream

The dense thin heat sink we see is made by this process. During forming, a small specially designed convex part is reserved at the edge of the fin, the fin is fixed in the customized die, and the convex parts are bent and locked with each other to form neatly arranged parallel fins. Combined with stamping, it is mainly used to manufacture parallel dense thin fins used in reflow welding or air duct design.

Folding heat dissipation has become the mainstream

 The folding method has obvious advantages: simple mechanical locking structure and less process; It can compensate the interface impedance generated by the subsequent connection between the fin and the endothermic bottom. One time equipment input can produce a large number of products. Now many heat pipe heat dissipation products on the market are connected in this way, which is stable and simple.

Welding heat dissipation forms are also mainstream

Welding is a familiar way of metal processing. The most commonly used welding method in heat sink processing is reflow welding, also known as reflow welding. At present, most heat pipe radiators are connected by welding. Because the bonding degree of the welding joint directly affects the heat dissipation effect, the welding cost is high.

4. Various process forms of heat sink fins machine

In fact, in addition to the above-mentioned heat dissipation process forms, we can often see forging, gear shaper and other heat sink processes. These processes still appear in our computer heat dissipation forms more or less, but they are less and less for reasons of cost or heat dissipation effect, but these still contribute to the development of heat sink process.

Compared with everyone who already knows the structure and manufacturing process of heat sink fins machine, the survival of the fittest is suitable wherever it is. Through the above analysis, you must also understand that many process knowledge is short-lived, and many processes are aimed at some fields. There are only a few common ways involved in our desktop applications. It is not difficult to choose a high-performance and affordable heat dissipation product by grasping its main features.