The light decay of the light-emitting diode means that after a period of use, the luminous intensity of the light-emitting diode will be lower than the initial luminous intensity and cannot be restored. The reduced part is the light decay of the light-emitting diode, which causes the main failure of the light-emitting diode. The mechanism is the aging and discoloration of the potting colloid material. When the light-emitting diode is energized, it will generate heat, causing local temperature rise. The current potting gel is generally not high in temperature resistance. When the potting gel is above the temperature limit for a long time, it will cause irreversible damage, thus Cause the light-emitting diode to fail. It should be noted that after the light-emitting diode is energized, its luminous intensity will decrease as the junction temperature of the chip increases, but as long as the initial luminous intensity of the light-emitting diode remains unchanged, it cannot be regarded as light decay. The light attenuation of light-emitting diodes is an irreversible attenuation failure phenomenon caused by damage to the light source material.
In addition, the fusing of the light-emitting diode bonding wire is also a common failure mechanism that causes the light-emitting diode to open. Under the working state of the light emitting diode, if the current on the bonding wire exceeds the limit that the device itself can bear, it will fuse. The main reasons for the fusing of the light-emitting diode bonding wire are: excessive use of the device, power surge, deterioration of the device itself, poor heat dissipation, etc.
