The reason for the heat of the LED is that the electric energy is not all converted into light energy, but partly converted into heat energy. LED light efficiency only 100lm/w, its electro-optic conversion efficiency is about only about $number. That means about 70% of the electricity is turned into heat.
Specifically, led junction temperature is caused by two factors:
1. The internal quantum efficiency is not high, that is, when the electron and the hole are compounded, the photon is not 100%, which is usually called the "leakage of the current", which reduces the compound rate of the PN region carrier. The leakage current times the voltage is this part of the power, which is converted to thermal energy, but this part does not constitute the main component, because the internal photon efficiency has nearly 90%.
2. The internal photons cannot be emitted entirely outside of the chip and eventually converted to heat, which is mainly because this is called the external quantum efficiency of only about 30%, most of which translates into heat.
Heat Dissipation method
Aluminum fins: This is the most common form of heat dissipation, with aluminum fins as part of the shell to increase the heat dissipation area.
Thermal conductive plastic shell: fill the plastic shell when injection molding material, increase the thermal conductivity of plastic shell, heat dissipation capacity.
Air hydrodynamics uses the shape of the lamp shell to create convection air, which is the lowest cost of the enhanced heat dissipation method.
The inside of the fan lamp shell with longevity and high-efficiency fan to strengthen the heat dissipation, low cost, good effect. But to change the fan is troublesome, also not suitable for outdoor, this design is relatively rare.
The heat conduction heat pipe utilizes the conduction heat pipe technology, and the thermal energy is led to the shell fins. In large lamps, such as street lamps are common design.
Surface Radiation heat Treatment lamp shell surface to do radiation heat treatment, simple is the use of Shengwai radiation heat coating, you can radiate heat from the surface of the lamp shell.
