Influence factors of LED light failure briefly - (AddTime ： 2013-02-17)

200W led floodlights and lanterns as a new type of green lighting lamps and lanterns, energy saving, environmental protection, long life, well received by the customer to pursue honors. But the LED light failure problem, it is a 200W led floodlights and lanterns have to face the problem. Uninterrupted light failure, serious impact on the use of 200W led floodlights and lanterns.

At present, the market of the white LED light failure may be to civil lighting into one of the primary problems. What was the reason for the failure of the LED light? Generally speaking, in view of the LED light failure mainly has two factors:

A, LED the product itself quality problem:
1, the LED chip constitution is bad, brightness decay faster.
2, production process defects, the LED chip cooling not good from PIN feet derived, resulting in high temperature LED chip to chip attenuation intensifies.
Second, the conditions of use problem:
1, LED to constant current drive, some LED the voltage driver makes LED attenuation over.
2, drive current is greater than the rated driving conditions.
In fact lead to LED products light failure for many reasons, the most key or hot problems, although many firms in secondary products do not pay special attention to the problem of heat, but these secondary LED products use for a long time, the light failure than to the degree of cooling LED products to high. LED chip itself thermal resistance, silver glue, the influence of the base plate of the cooling effect, and colloidal gold line and also with the light of the relationship between the failure.
Three influence 200W led floodlights and lanterns quality light failure factors
First of all, choose what kind of LED white light.
This is very important, LED white light quality can say is a very important factor. Give some examples, the same with crystal yuan 14 mil white section chip as a representative, with common epoxy resin do bottom glue and BaiGuangJiao and packaging glue package out of the white light LED, single light in 30 degrees environment, after one thousand hours, attenuation data for light failure 70%; If you use class D low failure glue packaging, in the same aging environment, hours light failure is 45%; If C low failure glue packaging, in the same aging environment, hours light failure is 12%; If the class B low failure glue packaging, in the same aging environment, hours light failure for - 3%; If A kind of low failure glue, in the same aging environment, hours light failure for - 6%.
Secondly, the 200W led Flood light bead working environment.
According to the single LED white light age data to see, LED white light if only one light work, at the same time, it in place of the environment temperature is 30 degrees of words, so, single LED white light work support temperature not more than 45 degrees. This time, the secondary LED life will be very ideal.
If there are 100 single LED white lamp light at the same time, the interval between them is 11.4 mm, so, the light of surrounding LED white light support temperature may also not more than 45 degrees, but the lamp of the middle of the white light LED those more likely to achieve the high temperature of 65 degrees. This time, the 200W led Flood light bead is a test. So, in the middle of gather those LED white light, theory glazing failure will be faster, and the light of surrounding LED white light, the light failure will slowly.
Anyway, everyone should know, LED is afraid of hot, the higher the temperature, the LED life is short, the temperature is lower, LED life is longer. LED the ideal working temperature is certainly in the negative 5 to between zero. But this is basically impossible.
So, we know that 200W led Flood light bead ideal working parameters, as far as possible in the design of lamps and lanterns, strengthen the function of the thermal conductivity, heat dissipation. Anyway, the lower the temperature, LED life is longer.
Again, 200W led Flood light bead work electrical parameter design.
According to the experimental results, the LED white light in the drive current is lower, the quantity of heat of emission is smaller, of course, the brightness of the small. According to the survey, LED solar lighting circuit design, LED drive current general just 5-10 ma, The lamps and lanterns of lamp bead with large number of products, such as to achieve a more than 500, or more, drive current general just 10-15 ma, and generally popular LED lighting application of drive current, just 15 - ma, seldom someone put the current design to more than twenty ma.
And the experimental results also show that the 14 ma drive electric shed, and, with a lid don't leak, the air inside the temperature reached 71 degrees environment, low failure products, hours light failure is zero, 2000 hours of light failure is 3%, this means that the low failure LED white light in such an environment use has reached its utmost, again big is a kind of damage.
Because aging with aging plate no cooling function, therefore, LED work produce heat conduction is basically can't go out of. The experiment to this point. Aging plate inside air temperature has reached the high temperature of 101 degrees, aging board cover surface temperature is only 53 degrees, the difference of degrees. This shows that the design of this kind of plastic cover basically do not have heat conduction heat dissipation function. But the general design of lamps and lanterns, considering the thermal cooling function. So, in summary, 200W led Flood light bead work electrical parameters should be designed according to the actual situation, if the lamps and lanterns of thermal cooling function is very good, the LED white lamp drive current increase point is it doesn't matter, because the 200W led Flood light bead work heat produced by the moment can export to outside, no damage to LED, LED the best is to care for. On the contrary, if the lamps and lanterns of thermal cooling function just so so, had better put a little circuit design, let it please put less heat out.