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COB knowledge of flat light sources

时间:2017-04-06 10:28:19    来源:

What is the cause of a.COB flat light source and a dead light?
The COB flat light source has several chips, the direct wire is welded on the PCB substrate, and the electrical connection between the chip and the substrate is realized by a lead suture method. The surface layer structure of the COB flat light source substrate is provided with an insulating layer, a copper foil, a super bright and high temperature resistant insulating ink (the surface is bright white), and a copper foil used for arranging and arranging (LAYOUT) mixed connecting lines.
COB flat light source, dead light, its core is circuit disconnection, and the following factors:
1, the PCB substrate surface layer copper foil wiring process enters the dust particle, causes the open circuit
2, the surface of the gold solder joint is oxidized
3, the surface has aluminum chips, not cleaned up directly welded
4. The wire is broken
5, the chip itself quality problems
Therefore, to make the COB flat light source deathless, control the above 5 details, and increase the reliability of the COB flat light source.
Two.COB flat light source, color rendering (CRI) index increases, which factors are related?
COB flat light source color rendering (CRI) refers to the COB surface light source to illuminate the true color of the object. The color rendering index (RA) is the color rendering ability of light sources to objects. The COB plane light source method to improve the color rendering index is the most commonly used with pink, pink selection in relation to the light efficiency and stability of the COB plane light source. A red nitride and silicate, suggested the use of nitride (such as pink intematix, TOYOTA, etc. the synthesis of RCM is a better choice).
COB plane light source with nitride, the color index increases, but the color deviation, light effect will be reduced. Brightness and color rendering index can not be increased at the same time, improve the COB plane light source color index key is to make pink excitation spectrum broadband widening trend long direction, but the brightness will naturally reduce. As far as COB packaging technology is concerned, it can generally be 80~90, and the warm white light will be 5~8 LM low. The intensity of light intensity will obviously decrease when the explicit index is higher than 90.
Three.LED flat light source over UL, safety certification, COB package or MCOB package?
LED flat light source through UL safety certification, generally require high pressure 2200V above, export market in Japan requirements of high pressure 3800V. MCOB flat light source is a multi cup and multi chip integrated packaging structure. The multi cup edge insulating layer is opened and subjected to high voltage. The surface layer of the COB flat light source has a solid insulating layer, and the dielectric constant of the insulating layer is 2.0~4.0. The insulation performance is good, and the shock resistance of 2200V is higher than that of the high voltage. LED plane light source voltage and LED plane light source Naiduo high insulation performance of the insulation layer, and dielectric constant of the.
To sum up, LED plane light source requirements UL, safety certification, using COB packaging is better.
What are the applications of the four.LED flat light source (COB flat light source)?
LED planar light source (COB flat light source) is energy saving and environment friendly. Multi core integrated package is used on aluminum substrate or ceramic substrate. The utility model has the advantages of low thermal resistance, good heat dissipation effect, low cost, simple and convenient installation, uniform and soft light, no spot, etc., and is favored by household and commercial decorative lighting.
It is mainly used in lighting, counter lighting, jewelry irradiation, medical instrument lighting, home decoration, lighting and so on.
Applications: shopping malls, indoor, clothing, cabinets, living rooms, corridors, hotels, bedrooms, kitchens, etc..
Application: T5/T8/T10 fluorescent tube, lamp bulb lamp, lamp, wall lamp, ceiling lamp, Par lamp, ceiling lamp, reading lamp, lamp, lamp, lamp, Lamp jewelry plant
Five. How to reduce the junction temperature of the LED flat light source (COB flat light source)?
One of the most important factors affecting the lifetime and luminous efficiency of LED planar light sources (COB flat light sources) is junction temperature. The junction temperature of LED planar light source (COB flat light source) refers to the LED flat light source (COB flat light source), which integrates the temperature of the LED layer of the LED chip, the temperature of the P-N junction, and the core of which is the problem of heat dissipation. LED plane light source (COB plane light source) related with the factors and below the junction temperature of the chip package structure, thermal resistance, thermal resistance of the LED chip itself the two radiating body (especially light resistance), thermal conductivity and heat radiator area, plane light source module and the two radiating body interface thermal resistance, COB plane light source the aluminum substrate (or ceramic substrate) of the thermal resistance, the structure of the lamp, rated power input size and ambient temperature.
The lower the junction temperature of LED flat light source (COB flat light source), the longer the service life. Based on the comprehensive consideration of the luminous efficiency and lifetime of the LED flat light module, the optimum method is to control the junction temperature of the LED flat light source below 60 degrees, regardless of the power size. The solution to heat dissipation is to reduce the junction temperature and reduce the temperature rise:
1, to improve the efficiency of LED chip electro-optic conversion, as much as possible the input power into light energy.
2, reduce the LED chip and peripheral lamp heat sink block, so as to improve the LED chip and peripheral lamp heat dissipation ability.
3, the reasonable design of the lamps and lanterns, the shell material and the selection of the COB flat light source board material, the purpose is to reduce the thermal resistance of the LED flat light source (COB flat light source).
Six.LED plane light source (COB flat light source), luminaire with isolated power or non isolated power?
LED plane light source (COB plane light source) what kind of power supply does the luminaire use well? This is a problem often encountered by designers of LED light fixtures. The current power supplies are isolated and non isolated, and the isolated power supply is compared with the non isolated power supply as follows:
As can be seen in the above table, isolated power and non isolated power supply


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