LED light fade definition and influencing factors

What is LED light failure

The decline of LED products is that the signal in the transmission of light is weakened. At this stage, the level of LED light failure made by the global LED manufacturers is different. The high-power LED also has light decay, which has a direct relationship with temperature. It is determined by the chip, phosphor and packaging technology. At present, the decline of white LEDs in the market may be one of the most important issues for civilian lighting.

Two factors that affect the LED light failure

1, LED quality problems

(1) The LED chip used is not good in physical quality and its brightness decays rapidly.

(2) There is a defect in the production process, and the heat dissipation of the LED chip cannot be well derived from the PIN pin, resulting in an excessively high temperature of the LED chip, which intensifies the attenuation of the chip.

2, the use of conditions

(1) The LED is driven by a constant current, and some of the LEDs are driven by voltage to cause the LED to attenuate.

(2) The drive current is greater than the rated drive condition. In fact, there are many reasons for the decline of LED products, the most critical issue is the heat, although many manufacturers do not pay special attention to the issue of heat dissipation in the secondary products, but these secondary LED products under long-term use, the degree of light failure than the focus on heat dissipation The LED product is higher. The thermal resistance of the LED chip itself, the effect of the silver paste, the heat dissipation effect of the substrate, and the colloidal and gold lines are all related to light failure.

One of the main problems faced by white LEDs is the problem of lifetime. Since the price of white LEDs is still very high, if users want to gain a foothold in the lighting market and allow users to save electricity and save money, they have to make up for the long-life electricity savings. The high price of lamps. For now, the lifespan of white LEDs makes it difficult to do this.

From the normal use of LEDs, the most important factor that affects the life of LEDs is heat. The source of heat is the Joule heat generated by the normal electrical resistance of the material, the heat generated by the PN junction, the Joule heat generated by the parasitic resistance brought about by the process, and the heat generated when the light is attracted. The accumulation of heat causes the temperature to rise, and the increase in temperature causes the performance of the chip to deteriorate, degenerate, and degenerate.