LED light attenuation definition and influencing factors

1. What is the light decay of LED light-failed LED products? The signal attenuation of light in transmission is weakened. At this stage, the LED products produced by global LED manufacturers have different degrees of light decay, and high-power LEDs also have light decay. Temperature has a direct relationship, mainly determined by chips, phosphors and packaging technology. At present, the light fade of white LEDs on the market may be one of the top issues for civilian lighting.

2. Two factors affecting LED light decay

1) LED quality problems • The LED chip used is not good, and the brightness is attenuated faster.
• There are defects in the production process, and the heat dissipation of the LED chip cannot be well derived from the PIN pin, resulting in an excessive temperature of the LED chip, which intensifies the chip attenuation.

2) Conditions of use • LEDs are driven by constant current, and some LEDs use voltage driving to attenuate the LEDs.
• The drive current is greater than the rated drive condition. In fact, there are many reasons for the light decay of LED products. The most critical issue is the hot issue. Although many manufacturers do not pay special attention to heat dissipation in secondary products, the long-term use of these secondary LED products will reduce the degree of light attenuation. LED products should be high. The thermal resistance of the LED chip itself, the influence of the silver paste, the heat dissipation effect of the substrate, and the colloid and gold wire are also related to the light decay.

One of the main problems currently faced by white LEDs is the longevity problem. Since the price of white LEDs is still very high, if you want to establish a foothold in the lighting market and let users save electricity and save money, they must make up for the long-life and saved electricity bills. The high price of the luminaire. For now, the life of white LEDs makes it difficult to do this.

From the normal use of LEDs, the most important factor affecting the life of LEDs is heat. The source of heat is the Joule heat generated by the normal 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 by the attraction of the light. The accumulation of heat causes the temperature to rise, and the temperature rise causes the performance of the chip to decline, degenerate, and denature.

Edit: Sophy