Heat sink is small, but it is heat electronic components heat the magic device. For example, the computer will be heated for a long time, and the heat sink in the CPU can play the role of cooling, so that the computer can extend its working life. In the TV set, the power supply is light, and the heat sink is also placed in the tube.
So how is the Aluminum heat sink made and how does it work? Let’s talk more about that.
Material options for heat sink
There are many kinds of material options for the heat sink. There are silver, copper, aluminum, and steel. Different materials have important influence factors on the heat dissipation effect of the heat sink.
From the thermal conductivity analysis, the best is silver, but silver is not the first material, because the price of silver is too expensive. Copper is next in terms of thermal conductivity, which is almost twice that of aluminum, but it has to be said that aluminum is the most commonly used material. No matter the price or thermal conductivity, aluminum is the most comprehensive material. Aluminum is cheap and light.
How does the Aluminum heat sink work?
The heat sink works on a very simple principle. That’s by increasing the surface area. So the requirements of the heat sink is very fast heat absorption, heat loss is also very fast, play a good heat transfer effect.
Common manufacturing solutions for Aluminum heat sink
Extrusion of Aluminum heat sink
Extrusion process is suitable for mass production of Aluminum heat sink with less investment, short development cycle, low production cost. Commonly used aluminum extrusion material is aluminum 6063, has good thermal conductivity. The working principle is to heat the aluminum ingot to 520-540℃ at high pressure to let the aluminum liquid flow through the extrusion mold with grooves to make the heat sink embryo. And then cut the heat sink embryo, profile groove and other processing is made of the heat sink fin we commonly see. But making it through this process has its drawbacks. Aluminum extrusion process to make the Fin.
Fin thickness and length ratio limited to a certain range, pin-fin ratio. It is one of the main standards for testing aluminum extrusion technology. The larger the PIN-FIN ratio is, the larger the effective cooling area of the heat sink is. It is difficult to improve the heat dissipation area in a limited space, so the heat dissipation effect of aluminum extrusion fins is not so ideal. In the heat sink processing, aluminum extrusion process is mainly used to make lamellar fins or columnar fins.
Machined Aluminum heat sink
Aluminum machining involves a variety of processes, such as turning, drilling, milling, and grinding. This process can be flexibly applied according to the structure of the parts, the use of most structural parts, such as plate forming, heat sink grooving, bottom surface dressing, etc. But the disadvantage is that the tool wear will be relatively fast, the need for human participation in machine management, occupy a certain labor cost.
Die casting of Aluminum heat sink
The principle of die casting aluminum heat sink aluminum is similar to injection molding.
The raw material of aluminum alloy is dissolved into liquid at high pressure, and then the liquid material is quickly filled to CNC is a common process in cutting. According to the model, die casting machine started to work, one-time die casting molding, after cooling and subsequent treatment, made into a monomer heat sink. The process can be integrated into a thin, dense or complex fin design. The disadvantage of this process is that it affects the heat conduction effect and the mechanical properties of the material and the nuclear thermal conductivity can’t achieve the best of both worlds.
Which common surface finish options can be choose for Aluminum heat sink?
Sandblasting can strongly impact the surface of the workpiece under high pressure, and effectively remove some dirt or knife lines on the surface of the machined aluminum parts. It can also make the parts look more uniform and shiny, and improve the mechanical properties and fatigue of the Aluminum heat sink surface.
Brushed surface treatment can make the parts more metallic sense, appearance more fashionable sense.
In addition to decorative role, drawing can also increase the heating area of parts to a certain extent, promote the use efficiency of the Aluminum heat sink.
Anodized is one of the most widely used surface treatment methods for Aluminum heat sink today. Through anodized, the surface of the parts will travel a layer of protective film, not only can scratch resistance, wear resistance and loss resistance, protect the parts, but also to overcome the surface hardness of aluminum alloy defects.
Electroplating can effectively protect and decorate the Aluminum heat sink. The principle is similar to anodized. It is also a layer of protective film on the surface of the parts to prevent the anodized of the surface of the parts. At the same time, it also improves the wear resistance, reflection, electrical conductivity and corrosion resistance of the parts.