Do You Know the Production of Aluminum Profile Heatsink

Production of Aluminum Profile Heatsink

As a kind of material shell widely used in electronic and electrical industry, heatsink can not only protect internal power components from collision, but also helps power components heat conduction and heat dissipation, creating a safe and stable operation environment for components. The heatsink has very high requirements in shape design and dimensional accuracy, such as extrusion heatsinks, cast heatsinks, VC heatsinks and so on. So how can heatsink manufacturers produce aluminium heatsinks with good heat dissipation effect?

1. Quality Requirements of Ingots

The alloy composition of the aluminum alloy ingot of the heatsink should strictly control the impurity content to ensure the purity of the alloy. For the 6063 alloy, the content of Fe, Mg, and Si should be controlled. The content of Fe should be less than 0.2%. The content of Mg and Si are generally controlled at the lower limit of the national standard, the Mg content is 0.45% - 0.55%, and the Si content is 0.25% - 0.35%. The ingot is subjected to sufficient homogenization treatment to make the structure and performance of the ingot uniform. The surface of  ingot should be smooth. The end face of the ingot should be flat.

2. Mold Requirements

Because the heatsink aluminum profile mold has a lot of elongated teeth, it has to bear a large pressing force, and each tooth must have high strength and toughness. If there is an obvious difference in performance between each other, it is easy to cause breakage of those teeth having poor strength or toughness. Therefore, the quality of the steel must be reliable, it is best to use H13 steel produced by reliable quality manufacturers, or use high-quality imported steel. The heat treatment of the mold is very important. It is necessary to use vacuum heating and quenching. It is best to use high-pressure pure nitrogen quenching to ensure uniform performance of the various parts of the mold after quenching. After quenching, three times of tempering should be taken to ensure the hardness of the mold is sufficient under the premise of HRC48-52. This is an important condition for preventing the aluminum profile of the heatsink from being broken. Because alloy steel molds have better rigidity and wear resistance, are less prone to deformation, and are favorable for forming heat-dissipating profiles, it is also a good method to use inlaid alloy steel molds for well-designed profiles.

3. Reducing Extrusion Force

The squeezing force should be minimized to prevent the mold teeth from breaking. The squeezing force is related to the deformation resistance of the alloy, the state of the ingot and so on. The cast rod of the aluminum profile of the extruded radiator should not be too long, about 0.6-0.85 times the normal length of the cast rod. Especially in the first test, in order to ensure the smooth production of qualified products, it is better to use a shorter cast rod, about 0.4-0.6 times the normal length of the cast rod. After successful trials, normal ingots can be used for production. The ingot homogenization annealing not only makes the structure and properties uniform, but also improves the extrusion performance and reduces the extrusion force. The cross-sectional area of the aluminum profile of the radiator is generally large, the extrusion coefficient is generally less than 40, so the influence of the degree of deformation is small.

4. Extrusion Technology

The key to producing heatsink aluminum profiles is the first test. If conditions permit, a simulation test can be performed on the computer to see if the working belt of the mold design is reasonable, and then the mold is tested on the extruder.  When pressed upwards, the operator should cause the main plunger to slowly advance at a low pressure below 8 MPa. It is best to illuminate the exit of the mold with a flashlight. After each heatsink of the mold is evenly extruded into the hole, the extrusion can be accelerated gradually under pressure. When the aluminum profile heatsink is continuously extruded, attention should be paid to controlling the extrusion speed to achieve smooth operation. In the production of heatsink aluminum profiles, attention should be paid to the heating temperature of the mold so that the temperature of the mold is close to the temperature of the ingot. If the temperature difference is too large, the metal temperature will decrease due to the slow extrusion speed during extrusion, and clogging or uneven flow rate may occur.

The aluminum heatsink, as a kind of heat dissipation tool with high heat dissipation efficiency, has been widely used in the electronic industry. However, different aluminium heatsink manufacturers have different technological processes and refer to different production standards. The aluminium heatsink produced will have different advantages and disadvantages in radiation effect.