The solution for LEDs' heat dissipation
Solve the heat LED, mainly from two aspects, before and after encapsulation package, can be understood as the heat radiating LED chip and LED lamps
LED chip cooling mainly the selection process with the substrate and the circuit, since the city made any LED lamps, so the heat generated by the LED chip by the end of the lamp housing is always 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 a long time in a high temperature state, its life will soon be shortened. However, these calories can really guide the chip to the external 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 substrate PCB, through the thermally conductive glue only to the aluminum radiator. Therefore, the heat LED lamps
actually include thermal conductivity and dissipation in two parts.
However, LED lights shell size and thermal power based on the use of premises, there will be different options. There are the following cooling methods:
Aluminum fins: This is the most common heat sinks, aluminum fins as part of the housing to increase the cooling area.
Thermal plastic case: a thermally conductive material when filling plastic injection molding, plastic housing increases thermal conductivity, heat capacity.
Air fluid mechanics: the use of the lamp envelope shape, create a convection air, which is the lowest cost way to enhance heat dissipation.
Fan: lamp shell internal reinforcing long life and efficient cooling fan, low cost, good effect. But want to change the fan is more trouble, not suitable for the outdoors, this design is more rare.
Heat exchanger tube: the use of a heat exchanger tube technology, the heat conduction from the LED chip to the housing fins. In large lighting, such as street lamps is a common design.
Surface radiation heat treatment: light shell surface radiation heat treatment done, the simplest is to smear Chi Shing Wai Wah heat radiation paint, radiant heat mode can be removed from the surface of the lamp envelope.
The following describes a new type of thermal coating: ZS-411 radiation thermal cooling coatings, paints and coatings having a high thermal conductivity and a large heat dissipation surface area, while over a wide wavelength range (1-20μm) with high emissivity, can significantly improved include conduction, convection, radiation, heat overall performance.
Overall, LED luminous
efficiency is still relatively low, causing the junction temperature rise and reduce life expectancy. In order to reduce the junction temperature in order to improve life we must attach great importance to the problem of heat.