The influencing factors of the LED light failure description
LED as a new type of green lighting lamps and lanterns of lamps and lanterns, energy saving, environmental protection, long life, admired by our customers. But the LED light failure problem, it is a problem of LED lamps and lanterns have to face. Uninterrupted droop, the serious influence the usage of the LED lamps and lanterns.
of two factors lead to droop
for now, the white LED the droop may be on the market into civil lighting one of the primary problem. What causes the LED light failure? In general, for the LED light failure
one, there are mainly two factors LED product itself quality problems
1, the LED chip physique is bad, the brightness decay rapidly.
2, the deficiency in the production process, the LED chip heat dissipation can't good derived from PIN feet, cause the LED chip temperature chip attenuation.
2, conditions of use
1, LED constant current drive, driven by voltage makes some LED LED attenuation.
2, drive current is greater than the rated driving conditions.
in fact, some of the reasons for LED products light failure, the key still hot problems, although many vendors in the secondary products with a special focus on the cooling problem, use for a long time, but these secondary LED product will droop degree higher than pay attention to the heat dissipation of LED products. LED chip itself, the influence of thermal resistance, silver glue, substrate cooling effect, and colloid gold thread and also have a connection with light failure.
affect the quality of LED lamps and lanterns droop three big reasons for
first of all, choose what kind of LED white light.
this is important, the quality of the LED white light can be said to be the very important factor. Give some examples, the same represented by wafer 14 mil white light section of the chip, made of common epoxy resin glue and Bai Guangjiao and glue packaging LED white light, single light in 30 degrees environment, after one thousand hours, attenuation data to droop 70%; If encapsulated with low class D failure glue, in the same aging conditions, thousands of hours of light failure is 45%; If the C class low failure glue encapsulation, in the same aging conditions, thousands of hours of light failure is 12%; If a class B low failure glue encapsulation, under the same aging environment, light failure for - thousands of hours 3%; If class A low failure glue, in the same aging conditions, light failure for - thousands of hours 6%.
second, LED lamp bead working environment temperature.
data according to single star LED white light aging, LED white light if there is only one light work, at the same time, it's environment temperature is 30 degrees, so, a single LED white light work of stent temperature not more than 45 degrees. This time, the service life of the LED will be ideal.
if there are 100 white light LED lights work at the same time, the interval between them is only 11. Under the condition of 4 mm, then the lights around the pile of white light LED stent temperature may also can't more than 45 degrees, but those LED white light lamp in the middle of the pile could reach the high temperature of 65 degrees. This time, the LED lamp bead is a test. So, gathered in the middle of the white light LED, theory of glazing failure will be a bit faster, and the light surrounding the pile of white LED lamp, light failure will slow down a little.
anyway, you should know, LED is afraid of heat, the higher the temperature, the shorter the LED life, the lower the temperature, LED the longer service life. LED the ideal working temperature of course is between negative 5 to zero. But it is basically impossible.
so, we know that LED lamp bead ideal working parameters, just as much as possible in the design of lamps and lanterns, enhance the thermal conductivity, heat dissipation function. Anyway, the lower the temperature, LED the longer service life.
once again, the LED lamp bead work electrical parameter design.
according to the experimental results, the LED white light under the condition of the drive current is lower, the smaller the emission quantity of heat, of course, and the smaller brightness. According to the survey, LED solar lighting circuit design, LED drive current generally 5 - 10mA; Lamp bead with large number of products used in the lamps and lanterns, such as more than 500, or more, the drive current is only 10 - in general 15 ma, and generally popular application of LED lighting drive current, just 15 Ma, rarely put to over 20 ma current design.
and the experimental results also show that in 14 ma driver power flow, and add the lid not leak, the inside of the air temperature of 71 degrees Fahrenheit, low failure products, thousands of hours of light decays to zero, 2000 hours of light failure is 3%, which means the low failure LED white light is used in such an environment has reached its maximum, again big is a kind of damage of it.
because there is no heat aging with aging board function, so the LED work the heat generated by the transmission is basically can't go outside. The experimental understands that the Shanghai. Aging board on the inside of the air temperature has reached 101 - degree heat, the lid of the aging board surface temperature is only 53 degrees, dozens of degree of difference. This means that, the design of the plastic cover basically do not have heat dissipation function of thermal conductivity. But, in the general design of lamps and lanterns are considering the heat conduction of heat dissipation function. Thus, in summary, the LED lamp bead work the design of the electrical parameters according to the actual situation, if the cooling function of thermal conductivity of lamps and lanterns is very good, the white light LED drive current increasing point is that it doesn't matter, because the heat generated by the LED lamp bead work moment can export to the outside, no damage to the LED, is the best care for the leds. On the contrary, if the cooling function of thermal conductivity of lamps and lanterns so so, had better circuit designed to be a little bit small, let it put less heat.
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