LED lamps cooling levels increase suggested parsing
The reliability of the LED lighting lamps and lanterns (life) depends largely on the heat dissipation, so improve the level of heat dissipation is one of the key technologies. Mainly to solve the excess heat generated by the chip through the heat sink, heat dissipation body out, this is a very complex technical problems.
LED lamps and lanterns of power, which LED to consider heat dissipation, power LED need to heat dissipation. The power LED is refers to the working current is more than 100 ma of light-emitting diodes. Line is our country the ASSIST union, defined by reference to the United States, according to the existing two LED the forward voltage of typical value of 2.1 V and 3.3 V, the input power of over 210 mw and 330 mw leds are power LED, all need to consider the device heat dispersion problem, some people may have different views, but practice has proved, to improve the reliability of power LED (life), consider the power LED heat dissipation problem.
Heat related parameters related to the LED heat dissipation of main parameters such as thermal resistance, moderate temperature.
Thermal resistance is refers to the effective temperature of the device and the external regulation reference point temperature difference divided by the number of devices in the steady state power dissipation of the quotient. It is said the device cooling degree of the most important parameters. The heat dissipation good power LED thermal resistance of 10 / W or less, domestic reports the best thermal resistance of 5 / W or less, foreign can reach thermal resistance 3 / W or less, if do this level can ensure the service life of power LED.
Refers to the LED junction temperature device for heating the main part of the semiconductor junction temperature. It is the LED device under the working conditions, the ability to withstand temperature value. Therefore the SSL plans to improve heat resistance target. Chip and heat resistance of phosphor is very high, the current has reached chip junction temperature under 150 , the phosphor powder under 130 , the basic life won't have any influence on the device. Chip phosphor higher heat resistance, the requirement of heat dissipation is low.
There are several different temperature rise of temperature, we discussed here is: shell - environmental temperature. It refers to the LED device shell (LED lamps and lanterns can detect the most hot) temperature and the environment (a flat surface in the light of lamps and lanterns, is apart from 0.5 meters of lamps and lanterns) temperature difference. It is a temperature can be measured directly, and can directly reflect the LED device peripheral cooling degree, practice has proved that in the ambient temperature of 30 , if measured LED tube shell for 60 , the temperature rise shall be the 30 , this basically ensures the service life of LED device value, such as temperature rise too high, LED light source, maintain rate will decrease greatly.
LED lamps and lanterns, heat dissipation new questions:
With the development of LED lighting products, there are two new techniques: first, in order to increase the flux of the single pipe, into the larger current density, such as mentioned below, so that the chip produce more heat, need to heat dissipation. Secondly, encapsulate the new structure, with the increase of the LED light source power, need more power LED chip set packaging together, such as lamps and lanterns of COB structure, modular, will produce more heat, the need for more effective heat dissipation structure and measures, which in turn to put forward new task heat dissipation, otherwise it will greatly affect the performance and life of LED lamps and lanterns.
Now, LED lamps and lanterns, heat dissipation total effectiveness 50%, there are a lot of energy to become hot. Second, the LED large current density and modular lamps and lanterns will produce more concentrated waste heat, need a good heat dissipation.
To raise the level of heat dissipation we offer the following Suggestions:
1), from the LED chip, to take the new structure, new technology, improve the LED chip junction temperature, heat resistance, heat resistance, and other materials, for the cooling requirements reduced.
2), and reduce the thermal resistance of LED device, adopts the new encapsulation structure, new technology, selection of thermal conductivity, good heat resistance, new materials, include metal adhesive materials, fluorescent powder mixed glue, etc., between the thermal resistance of 10 or less / W or lower.
3), reduce the heating up, as far as possible USES the heat dissipation material with good thermal conductivity, good vent way on the design requirements, make the heat spread out as soon as possible, for temperature should be less than 30 . In addition, improve the level of modular the heat dissipation of lamps and lanterns should be referred to the agenda.
4), there are a number of ways for heat dissipation, such as using heat pipe, of course, is very good, but should consider the cost factor, should be considered in the design of performance problems.
In addition, the design of LED lamps and lanterns in addition to improving the efficiency of lamps and lanterns and light distribution requirements, good appearance, to improve the level of heat dissipation, USES the material with good thermal conductivity, it is reported that the cooling body coated with some nano materials, the thermal conductivity increases by 30%. In addition, want to have good mechanical properties and sealing, heat dissipation and dustproof, the rise of temperature of the requirements of LED lamps and lanterns should be 30 .
----------Archled Technology Co.,Limited