Characteristics of finned heat sinks

The finned heat sink is a device used to dissipate heat from electronic components that are prone to heating in electrical appliances. It is made of aluminum alloy, brass, or bronze and comes in plate, sheet, or multi-plate forms. For example, the CPU in a computer requires a relatively large heat sink, while the power tubes, line tubes, and amplifier tubes in a television also need heat sinks. Generally, when in use, a layer of thermal grease should be applied to the contact surface between the electronic components and the heat sink to more effectively transfer the heat generated by the components to the heat sink, which then dissipates it into the surrounding air.

　　Fin heat sinkIt is a device for dissipating heat from easily heated electronic components in electrical appliances, made of aluminum alloy, brass, or bronze, and comes in plate, sheet, or multi-sheet forms. For example, the CPU in a computer requires a relatively large heat sink, and the power tubes, line tubes, and amplifier tubes in a television also need heat sinks. Generally, when in use, a layer of thermal grease should be applied to the contact surface between the electronic components and the heat sink to more effectively conduct the heat emitted by the components to the heat sink, which then dissipates it into the surrounding air.

Currently, commonly used heat sink materials are copper and aluminum alloy, each with its own advantages and disadvantages. Copper has good thermal conductivity but is expensive, difficult to process, heavy (many pure copper heat sinks exceed the weight limit of CPUs), has a small heat capacity, and is prone to oxidation. However, pure aluminum is too soft to be used directly; only used aluminum alloys can provide sufficient hardness. The advantages of aluminum alloy are low price and light weight, but its thermal conductivity is much worse than that of copper.

For high heat generation, fin heat sinks can be used for cooling because aluminum cannot achieve the cooling effect of copper. This is an inherent advantage of copper for heat dissipation due to its large heat capacity. In other words, fins made from this material absorb heat quickly but release it slowly. There is a lot of physical deposition of heat in copper sheets that requires pairing with high-power, high-speed fans to achieve ideal results.

Although fin heat sinks absorb heat slowly, they release it quickly; their cooling effect is proportional to their structure and workmanship. The more fins there are and the better the polishing at the bottom, the better the cooling effect. However, it is also limited by its manufacturing process. Generally, heat sinks made using aluminum extrusion manufacturing processes can only have a groove spacing of 1.1mm. The cooling principle is quite simple: it increases its contact area with air using the fins on the heat sink and then uses fans to accelerate airflow to carry away the heat from the heat sink. Aluminum heat sinks have low heat capacity and release heat quickly, allowing devices to work better and are much cheaper than copper heat sinks.

Both have their pros and cons. Copper has good thermal conductivity but is expensive, difficult to process, overweight, and prone to oxidation. However, pure aluminum is too soft to be used directly; only used aluminum alloys can provide sufficient hardness. The advantage of aluminum alloy is its low price and light weight, but its thermal conductivity is much worse than that of copper. Some heat sinks have their own merits; for example, aluminum alloy heat sinks may have a copper plate embedded in their base.