The decay of luminous flux over time is a characteristic of LEDs. The current standard for the life of LEDs is mainly L70, that is, when the luminous flux decays to 70% of the initial value, it is considered to be invalid. The period of use is the life. The life of mainstream LED lamps and lamps is roughly between 15000h-50000h, which is generally marked on the outer packaging. In addition, there is also the L50 standard and the more stringent L90 standard.
The life of LED lamps and lamps mainly depends on the electrolytic capacitors in the LED lamp beads and the driving power supply, both of which are affected by temperature. The aging of the driving power supply will cause the output current to decrease, and the light decay of the LED lamp bead comes from the decrease in the reflectivity of the silver layer of the bracket, the decrease in the yellow reflectivity of the bracket plastic, and the decrease in the refractive index of the hardening glue of the packaging glue, which leads to a decrease in external quantum efficiency , The internal quantum efficiency of the chip is reduced due to the ultra-high junction temperature, and the conversion efficiency of the phosphor due to high temperature and humidity is reduced.