The heat dissipation of the fins of the heat sink is mainly due to convection and radiation, of which convection is the most important. The basic formula for convection cooling is as follows: where: “dissipated heat, “heat convection coefficient,” heat sink cooling area, “temperature difference between the radiator surface and nearby air”. The basic formula for heat radiation dissipation is as follows: where: - the ability to exchange heat radiation, - the heat radiation coefficient of the surface of the object. ―The surface area of ​​the object, the relationship between the angle of the radiant heat exchange and the surface, the temperature difference between the surface and the surface, here is the temperature difference between the heat sink fin and the surrounding air. The heat dissipation of convection and radiation is proportional to the heat dissipation area of ​​the heat sink, so to improve the heat dissipation performance, the area of ​​the heat sink must be increased.

Current research on heat dissipation of LED lamps There are two main methods for heat dissipation of LEDs: one is to reduce the internal thermal resistance through the improvement of the internal packaging structure and packaging materials of the LEDs; the other is to improve the external heat dissipation efficiency by reducing the external thermal resistance. The package heat dissipation package is mainly made up of package structure and package material, and adopts low thermal resistance package structure and technology. Firstly, the thermal resistance of the selected substrate, bonding material and packaging material is low; secondly, the structural design should be reasonable, the thermal conductivity between the materials is continuously matched, and the thermal connection between the materials is good, so as to avoid a heat dissipation bottleneck in the heat conduction channel. Ensuring that heat is dissipated from the inside to the outer layer In order to solve the problem of packaging heat dissipation of high-power LEDs, various structures have been developed at home and abroad. In 2001, LumiLeds developed the A1GalnN power-type flip-chip structure in which heat is conducted directly from the solder layer to the Si substrate and then through the Si substrate and bonding material to the metal base. Wang Yaoming et al. designed a thin film encapsulation structure by magnetron sputtering process. The electrode electrode heat sink and insulation layer were directly formed on the metal heat sink in the form of a thin film, which reduced the thermal resistance of the internal heat sink. Luo et al. proposed a micropump structure in which water enters the small slot of the LED under the action of the micropump to absorb heat, and then returns to the micro water container to dissipate heat through the fan. Although the structure has good refrigerating properties, its structure is complicated.

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