How To Improve The Service Life Of White LED
Aug 02, 2021
Methods to improve the luminous efficiency of white LED is improving the structure of the chip and the encapsulation structure, to achieve the same level with low power white LED, the main reason is that current density increased by more than 2 times, not only from large chips to take out the light, the results will lead to the low luminous efficiency than power white LED, can improve the electrode structure of the chip, In theory, this problem can be solved.
The specific method to realize the uniformity of luminescence properties is to improve the packaging method of white LEDS. It is generally believed that the above problems can be overcome by improving the uniformity of the fluorescent material concentration of white LEDS and the manufacturing technology of the fluorescent material.
The specific contents of reducing thermal impedance and improving heat dissipation are:
1.Reduce the thermal impedance of the chip to the package.
2. to suppress the thermal impedance of the package to the printed circuit board.
3.Improve the smooth heat dissipation of the chip.
In order to solve the problem of longevity of white LED, the current LED manufacturers take the countermeasures to change the sealing material and disperse the fluorescent material in the sealing material, which can more effectively inhibit the deterioration of the material and the speed of light penetration reduction.
Although the siliceous sealing material can ensure the service life of 40000 hours in white LED, lighting industry have different opinions, however, the service life of the main arguments is a traditional incandescent lamp and fluorescent lamp has been defined as "brightness fell below 30%," brightness by half time of 40000 hours of white LED, if converted to brightness fell below 30%, About 20,000 hours left. There are two strategies to extend the service life of components, which are:
1. Inhibiting the overall temperature rise of white LED.
2. Stop using resin encapsulation.
The above two measures can achieve the service life of 40,000 hours when the brightness is reduced to 30%. The method of cooling white LED packaging printed circuit board can be used to suppress the temperature rise of white LED. The main reason is that the packaging resin will deteriorate rapidly under high temperature and strong light irradiation. According to The Arrhenus law, the service life will be extended 2 times when the temperature is reduced by 100℃.
