1. Cooling method
Generally speaking, according to the way of removing heat from the radiator, the radiator can be divided into active heat dissipation and passive heat dissipation.
The so-called passive heat dissipation means that the heat of the heat source LED light source is naturally dissipated into the air through the heat sink. The heat dissipation effect is proportional to the size of the heat sink, but because the heat is naturally dissipated, the effect is of course greatly reduced. In equipment that is not required, or used to dissipate heat for components that do not generate much heat. For example, some popular motherboards also adopt passive heat dissipation on the north bridge. Most of them adopt active heat dissipation. Active heat dissipation is forced by cooling devices such as fans. It can take away the heat emitted by the heat sink, which is characterized by high heat dissipation efficiency and small size of the equipment.
Active heat dissipation, subdivided in terms of heat dissipation, can be divided into air cooling, liquid cooling, heat pipe cooling, semiconductor cooling, chemical cooling, and so on.
2. Material selection:
Thermal conductivity (unit: W/mK)
Silver 429
Copper 401
Gold 317
Aluminum 237
Iron 80
Lead 34.8
1070 aluminum alloy 226
1050 aluminum alloy 209
Type 6063 aluminum alloy 201
6061 aluminum alloy 155
Generally speaking, ordinary air-cooled radiators naturally choose metal as the material of the radiator. For the selected material, it is hoped that it has both high specific heat and high thermal conductivity. It can be seen from the above that silver and copper are the best thermal conductive materials, followed by gold and aluminum. But gold and silver are too expensive, so the current heat sink is mainly made of aluminum and copper. In comparison, both 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 copper radiators have small heat capacity and are easy to oxidize . On the other hand, pure aluminum is too soft to be used directly. The aluminum alloy used can provide sufficient hardness. The advantages of aluminum alloy are low price and light weight, but the thermal conductivity is much worse than copper.
