Lighting Sense

LED bulbs heat up how to do it?

Public date:[2014-12-01]

LED bulb hot market, major brands Shop price dazzling, you also have your truth, there are cheap cheap market. Today it said one of the shortcomings of LED bulb: heat.

LED bulbs heat up how to do? LED will produce heat, a lot of people will think that LED is a cold light source, it only refers to the LED light-emitting principle only.


LED bulbs heat causes:

The reason is because the LED lamp of the added heat energy into light, and not all, but a portion is converted into heat, the electro-optical conversion efficiency of about 20 to 30%. That is about 70% of the energy is turned into heat.

Specifically, LED junction temperature is due to two factors caused by:

Internal quantum efficiency is not high, that is, when the electrons and holes recombine and generate photons are not 100%, often referred to as the "leakage current" PN area leaving the carrier recombination rate decreases. Leakage current multiplied by voltage is this part of the power, which is converted into heat, but this part does not account for the main component, because the internal photon efficiency is close to 90%.

Internally generated photons emitted to the outside of the chip can not be fully converted to heat and the last, which is the main part, because the current which is called an external quantum efficiency of only about 30%, mostly converted to heat up.

LED bulb cooling solution:

Solve the heat LED bulbs, mainly from two aspects, before and after encapsulation package, can be understood as LED bulbs LED chip cooling and heat dissipation. LED chip select and process heat primarily with the substrate and circuit related article describes temporarily. This paper describes the heat LED bulbs, because any LED lamps are made, so the heat generated by the LED chip always end by the lamp housing scattered into the air.

If the heat is not good, because the heat capacity of the LED chip is small, a little bit of accumulation of heat will make the chip junction temperature is rapidly increasing, if prolonged high temperatures in the state, its life will soon be shortened. However, these calories can really guide the chip to the outside air, to go through a lot of ways.

Specifically, the heat generated by the LED chip from its metal heat block out, go through the solder to the aluminum plate PCB, and then only by thermal plastic to aluminum radiator. So heat LED lamps hotel project actually includes thermal conductivity and heat dissipation in two parts.

However, LED lamp shell heat and the use of premises in accordance with the power level, there will be different options. There are several main cooling methods:

Aluminum fin: This is the most common way of cooling, aluminum fins as part of the housing to increase the cooling area.

Thermal plastic case: a thermally conductive material at the time of filling plastic injection molding, plastic housing increases thermal conductivity, heat capacity.

Air cooling fluid mechanics: air hydrodynamics use light shell shape, creating a convection air, which is the lowest-cost way to enhance heat dissipation.

Fans inside the lamp housing reinforced with long life and efficient fan cooling: low cost, good effect. But the trouble is that some fans want to change, does not apply to outdoor, this design is more rare.

Heat pipe cooling technology: the use of a heat pipe heat pipe technology, the heat from the LED chip lead into the housing fins. In large lamps, such as street lights, etc. This is a common design.

Surface radiation heat lamp shell surface treatment do radiation heat treatment: radiation heat smear is a simple paint, radiant heat can be taken away from the lights the way the shell surface.
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