LED light failure definition and influencing factors
1, what is LED light failure
LED products light failure is light in a transmission signals in the weakened, and LED to the present global consortium LED light failure degree different products, there is also a high power LED light and temperature, the decline has direct relation, mainly by chip, the fluorescent powder and packaging technology of the decision. At present, the market white LED the decline may be light to civil lighting the primary problem into one.
2, influence LED light failure of two factors
• the constitution is not good, brightness LED chips attenuated fast.
• production process defect, LED chips can't good heat from the feet, leading to PIN are LED to high temperature chip that chip attenuation intensified.
2) use conditions
• LED to constant current drive, and part of the LED the voltage driver makes LED attenuation to come over.
• drive current more than rated driving conditions. Actually lead to LED products for many reasons, the light; the key or hot question, although many firms in subprime products do not pay special attention to the problem of heat, but these subprime LED products use for a long time, the light failure extent will pay attention to the heat than have LED products to high. The LED chip itself thermal resistance, silver glue, effects of substrate to come loose hot effect, and colloid and gold line and all aspects and light failure have relations.
White LED now faces a major problem is life problems, because the price of white LED is very high, to the market, let on lighting users both save electricity and save money, rely on the long life and save the electricity to make up for the high price of lamps and lanterns. For now, the white LED life situation makes it difficult to do this.
From the normal use of LED to see, the influence of the main factors LED life is hot. The source of heat, the resistance of the electricity in normal material from the joule heat, heat generated by the PN junction, and process the stray resistance generated bring the joule heat and light attracted an hot. The accumulation of heat that temperature, temperature makes chips recession, aging, degradation performance degeneration