Why Are Most Heat Sinks Made Of Copper And Aluminum?

The general air-cooled heat sink will choose metal as the material of the heat sink. When we choose the heat sink material, we will evaluate it based on high specific heat and high thermal conductivity. Silver and copper are the best thermal conductive materials, followed by gold and silver. . However, gold and silver are generally rarely used in heat sink production because they are too expensive. It can be seen that cost is an important factor to be considered by heat sink manufacturers, while the cost of copper and aluminum is much lower, and heat sinks are formed mainly by Made of aluminum and copper.

Aluminum also includes aluminum alloy, and copper and aluminum are not perfect. Copper and aluminum alloy have their own advantages and disadvantages: copper has good thermal conductivity, but it is more expensive, difficult to process, heavy, and aluminum heat sink heat capacity It is small and easily oxidized. Pure aluminum is relatively soft and does not have load-bearing capacity, so aluminum alloys are used in a large proportion. Aluminum alloys can provide sufficient hardness. It has the advantages of low price and light weight, but its thermal conductivity is much worse than copper. The following custom heatsink manufacturer - Winshare introduces the characteristics of heat sinks of different materials:

Pure aluminum heat sink

Pure aluminum heat sink is more common, the manufacturing process is relatively simple and easy, and the cost is low. Because of the better thermal conductivity of pure aluminum, pure aluminum heat sink occupies more market share. The pure aluminum heat sink uses increased fins to increase the heat dissipation area. The commonly used processing method for pure aluminum heat sinks is aluminum extrusion technology. The main indicators of the heat dissipation performance parameters of the pure aluminum heat sink are the thickness of the heat sink base and the Pin-Fin ratio. Pin refers to the height of the fin of the heat sink, and Fin refers to the distance between two adjacent fins. The Pin-Fin ratio is the height of the Pin (excluding the thickness of the base) divided by the Fin. The larger the Pin-Fin ratio means the larger the effective heat sink area and the more advanced the aluminum extrusion technology. The aluminum heat sink manufacturer introduced that there are also more advanced production processes, such as Winshare Thermal’s shovel technology, which can achieve a higher Pin-Fin ratio and better heat dissipation performance.

Pure copper heat sink

The thermal conductivity of copper is 1.69 times that of aluminum, so under the same conditions, the pure copper heat sink can quickly remove heat from the heat source. In the classification of copper, copper with a copper content of more than 99% is called oxygen-free copper, the next grade of copper is copper with a copper content of 85% or less, followed by brass. Most of the copper heat sinks on the market use red copper. Copper also has obvious shortcomings. The high cost, difficult processing, and heavy heat sink hinder the application of all-copper heat sinks.

Copper and aluminum combined heat sink

By comparing the shortcomings of the two materials of copper and aluminum, some thermal design engineers recommend the combination of copper and aluminum. Some high-end heat sinks often use copper and aluminum combined manufacturing processes. These heat sinks usually use copper metal bases, and heat dissipation The fins are made of aluminum alloy. In addition to the copper bottom plate, there is also a way to add copper pillars to the heat sink. In addition, the copper heat pipe can also be buried in the aluminum heat sink bottom plate. Various combinations of copper and aluminum provide more choices for the selection of heat sink materials and processes. It is also a benefit for products with different heat dissipation requirements. In the future, there will be more ways to combine copper and aluminum, especially with the improvement of welding technology, copper and aluminum welding will become more and more mature.