LED heat dissipation technology and materials

Heat dissipation is a principal factor affecting the illumination intensity of LED lights. In order to achieve a better effect, all of the LED lights manufacturers and related research institutes have been working to improve the heat dissipation technology and materials.

In general, the heatsink can be divided into the passive heatsink and the active heatsink. Passive heat dissipation means that the heat of the LED light source is naturally radiated into the air through the heatsink, and the heat dissipation effect is proportional to the size of the heatsink. However, it can only be used in LED lights of relatively low power. For example, the aluminum PCB of the rigid LED light strip is equivalent to a heatsink. The high power LED lights such as the LED grow light commonly adopts active heat dissipation, that is, the heat emitted by the heat sink is forcibly taken away by the heatsink such as the fan, which is characterized by high cooling efficiency and the small volume.

Heat Conductivity Coefficient

As can be seen from the above table, silver and copper are the best thermal materials, followed by gold and aluminum. However, 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 the price is relatively expensive, the processing is difficult, the weight is too large, and the copper heat sink has a small heat capacity and is easily oxidized. On the other hand, pure aluminum is too soft to be used directly. The aluminum alloy used can provide sufficient hardness. The advantage of aluminum alloy is that it is cheap and light, but the thermal conductivity is much worse than copper. Of course, there are some radiators for other materials, such as fiberglass, ceramics, etc., and because of their price and process, they also have a place in the market.

The LED industry has extremely strict requirements on the alignment accuracy of the heat-dissipating substrate itself, and it needs to have characteristics such as high heat dissipation, small size, and good adhesion of metal lines. To improve LED luminous efficiency and service life, solving the heat dissipation problem of LED products is one of the most important issues at this stage.