2024-05-06
LED light bulb heat how to do?
LED light bulb heat how to do?
LED light bulb market, the major brand online store prices dazzling, expensive also have expensive reason, cheap also have cheap market. Today Xiaobian to talk about one of the disadvantages of LED bulbs: heat.
LED light bulb heat how to do? LED will generate heat, many people will think that LED is a cold light source, which only refers to the luminous principle of LED.
LED light bulb heat how to do? LED will generate heat, many people will think that LED is a cold light source, which only refers to the luminous principle of LED.
Causes of LED light bulb heat:
The reason why LED bulbs heat up is because the added electrical energy is not all converted into light energy, but part of it is converted into heat energy, and the electro-optical conversion efficiency is about 20 to 30%. This means that about 70% of the electricity is turned into heat.
Specifically, the generation of LED junction temperature is caused by two factors:
The internal quantum efficiency is not high, that is, when electrons and holes are combined, photons cannot be generated 100%, which is usually called the "current leakage" and the recombination rate of carriers in the PN region is reduced. The leakage current multiplied by the voltage is the power of this part, which is converted into heat energy, but this part does not account for the main component, because the internal photon efficiency is now close to 90%.
The photons generated inside cannot all be ejected to the outside of the chip and converted into heat, which is the main part, because the current so-called external quantum efficiency is only about 30%, most of which is converted into heat.
As mentioned earlier, although the light efficiency of incandescent lamps is very low, only about 151m/W, but it almost converts all the electrical energy into light energy and radiation out, because most of the radiation energy is infrared, so the light efficiency is very low, but it avoids the problem of heat dissipation.
The photons generated inside cannot all be ejected to the outside of the chip and converted into heat, which is the main part, because the current so-called external quantum efficiency is only about 30%, most of which is converted into heat.
As mentioned earlier, although the light efficiency of incandescent lamps is very low, only about 151m/W, but it almost converts all the electrical energy into light energy and radiation out, because most of the radiation energy is infrared, so the light efficiency is very low, but it avoids the problem of heat dissipation.
Heat dissipation solution of LED lamp:
To solve the heat dissipation of LED bulbs, mainly from two aspects, before and after packaging, it can be understood as LED chip heat dissipation and LED bulb heat dissipation. The heat dissipation of LED chip is mainly related to the selection and process of substrate and circuit, which is not elaborated in this paper. This article mainly introduces the heat dissipation of LED bulbs, because any LED will be made into a lamp, so the heat generated by the LED chip is always dispersed into the air through the shell of the lamp. If the heat dissipation is not good, because the heat capacity of the LED chip is very small, a little heat accumulation will make the junction temperature of the chip rapidly increase, if the long period of work in a high temperature state, its life will be quickly shortened. However, this heat can actually guide out of the chip to the outside air, through many ways. Specifically, the heat generated by the LED chip, from its metal cooling block, first passes through the solder to the PCB of the aluminum substrate, and then through the thermal glue to the aluminum radiator. Therefore, the heat dissipation of LED hotel engineering lamps actually includes two parts: heat conduction and heat dissipation.
However, the heat dissipation of the LED lamp shell will also have different choices according to the power size and the place of use. There are mainly the following methods of heat dissipation:
Aluminum fins: This is a common way to dissipate heat, using aluminum fins as part of the shell to increase the heat dissipation area.
Thermal conductive plastic shell: When the plastic shell is injected, the thermal conductive material is filled to increase the thermal conductivity and heat dissipation capacity of the plastic shell.
Aerohydrodynamic heat dissipation: Aerohydrodynamic uses the shape of the lamp shell to create convective air, which is a cost-effective way to strengthen heat dissipation.
Fan lamp shell with long life and efficient fan to strengthen heat dissipation: low cost, good effect. However, to change the fan is more troublesome, and it is not suitable for outdoor, this design is relatively rare.
Heat transfer tube heat dissipation technology: Heat transfer tube uses heat transfer tube technology to direct heat from LED chip to shell heat dissipation fin. In large lamps, such as street lamps, this is a common design.
Surface radiation heat dissipation treatment The surface of the lamp shell for radiation heat dissipation treatment: simple is to apply radiation heat dissipation coating, which can take the heat away from the surface of the lamp shell in a radiation way.
However, the heat dissipation of the LED lamp shell will also have different choices according to the power size and the place of use. There are mainly the following methods of heat dissipation:
Aluminum fins: This is a common way to dissipate heat, using aluminum fins as part of the shell to increase the heat dissipation area.
Thermal conductive plastic shell: When the plastic shell is injected, the thermal conductive material is filled to increase the thermal conductivity and heat dissipation capacity of the plastic shell.
Aerohydrodynamic heat dissipation: Aerohydrodynamic uses the shape of the lamp shell to create convective air, which is a cost-effective way to strengthen heat dissipation.
Fan lamp shell with long life and efficient fan to strengthen heat dissipation: low cost, good effect. However, to change the fan is more troublesome, and it is not suitable for outdoor, this design is relatively rare.
Heat transfer tube heat dissipation technology: Heat transfer tube uses heat transfer tube technology to direct heat from LED chip to shell heat dissipation fin. In large lamps, such as street lamps, this is a common design.
Surface radiation heat dissipation treatment The surface of the lamp shell for radiation heat dissipation treatment: simple is to apply radiation heat dissipation coating, which can take the heat away from the surface of the lamp shell in a radiation way.
