Analysis of the causes of LED light decay
As a new type of green lighting fixture, LED lamps are energy-saving, environmentally friendly and long-lived. The potential market is huge. However, the problem of LED light decay is another problem that LED lamps have to face. Uninterrupted light decay, seriously affecting the use of LED lamps。
For the time being, the light decay of white LEDs on the market may be one of the top issues for civilian lighting. In general, there are two main factors for the light decay of LEDs:
Firstly, the quality of LED products themselves:
1. The LED chip used is not good, and the brightness is attenuated faster.
2, the production process is defective, LED chip heat can not be well exported from the heat sink, resulting in high temperature of the LED chip to make the chip attenuation.
Secondly, the using conditions:
1. The LED is driven by a constant current, and some of the LEDs are driven by voltage to cause the LED to be attenuated.
2. 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 have a lighter degree of light. Cooling LED products should be high. The thermal resistance of the LED chip itself and the heat dissipation effect of the substrate are also related to light decay.
Three impact LEDs Lamp quality light fade factor
First of all, the choice of LED lamp beads.
The quality of LED lamp beads can be said to be a very important factor. LED chips of different production technologies have different speeds of light decay. For example, many manufacturers do not purchase original imported lamp beads. OAK purchases American original CREE LED lamp beads. The overall packaging technology is higher than other LED lamp beads in the same industry, which has great advantages in light efficiency and high temperature resistance.
Secondly, the LED lamp working temperature.
According to the CREE LED lamp bead aging data, when the LED lamp bead is working, the ambient temperature is 30 degrees, then the operating temperature of the single LED lamp bead is 60-70 degrees. This is the ideal working temperature for long-term use.
LED is afraid of heat, the higher the temperature of LED lamp bead, the shorter the life of LED, the lower the temperature of LED lamp bead, the longer the LED life. Therefore, when designing the luminaire, the function of heat conduction and heat dissipation is enhanced to extend the life of the LED lamp.
Thirdly, the working electrical parameters of the LED lamp bead are designed.
According to the experiment, the lower the current of the LED lamp bead, the smaller the heat emitted, and the smaller the brightness.
In summary, the design of the working electrical parameters of the LED lamp bead should be based on the actual situation. If the heat conduction and heat dissipation function of the lamp is very good, the heat generated by the operation of the LED lamp bead can be directly exported to the outside without damage to the LED.