Although the heat sink is small, it is an important device for dissipating heat from the heat-prone electronic components in the electrical appliance. For example, the computer will be heated for a long time, the heat sink in the CPU can play the role of cooling, which can prolong the life of the computer. So how is an aluminum heat sink made and how does it work?
Material Options for Heatsinks
Heat sinks are available in a variety of material options. Available in silver, copper, aluminum and steel. Different materials have important influence factors on the heat dissipation effect of the radiator. From the analysis of thermal conductivity, silver is the best, but silver is not the first material because the price of silver is too expensive. The thermal conductivity of copper is close behind, almost twice that of aluminum, but it must be said that aluminum is the most commonly used material. Regardless of price or thermal conductivity, aluminum is the material of choice.
How do aluminum heat sinks work?
The working principle of the radiator is very simple. That’s by increasing the surface area. Therefore, the requirement for the heat sink is that the heat absorption is very fast, and the heat loss is also very fast, which has a good heat transfer effect.
Common Manufacturing Solutions for Aluminum Heatsinks
The extrusion process is suitable for mass production of aluminum radiators, with less investment, short development cycle and low production cost. A commonly used aluminum extrusion material is aluminum 6063, which has good thermal conductivity. Its working principle is to heat the aluminum ingot to 520-540℃ under high pressure, so that the aluminum liquid flows through the extrusion die with grooves to make the heat sink. Then cut the heat sink blank, profile grooves and other processing processes, which are the heat sinks we usually see.
Aluminum extrusion process to make fins. The ratio of the thickness and length of the fins is limited within a certain range, the ratio of pin-fin type. It is one of the main criteria for testing aluminium extrusion technology. The larger the PIN-FIN ratio, the larger the effective cooling area of the heat sink. It is difficult to improve the heat dissipation area in a limited space, so the heat dissipation effect of the aluminum extrusion heat sink is not very ideal. In heat sink processing, the aluminum extrusion process is mainly used to make layered fins or cylindrical fins
CNC aluminum machining involves various processes such as turning, drilling, milling and grinding. The process can be flexibly applied according to the structure of the part, the use of most structural parts, such as plate forming, radiator slotting, bottom surface trimming, etc. However, the disadvantage is that the wear of the tool will be relatively fast, so manual participation in the machine management is required, which occupies a certain labor cost.
The principle of die cast aluminum heat sink is similar to injection molding. The aluminum alloy raw material is dissolved in the liquid under high pressure, and then the liquid material is quickly filled into the metal mold. According to the model, the die-casting machine starts working, one-time die-casting, and after cooling and subsequent processing, a single radiator is made. The process can be integrated into thin, dense or complex heat sink designs. The disadvantage of this process is that it affects the thermal conductivity and mechanical properties of the material, which are not the case for nuclear thermal conductivity.