An analysis on damage of light-emitting diodes reliability induced by electronic static discharge

The influence of different degrees of high reverse-bias stress on high power light-emitting diodes (LEDs) was investigated based on the aging of LED devices under the stress of 85 degrees C / 85 % RH. GaN-based blue LEDs were respectively tested by negative Human-Body-Mode (HBM) electronic static discharge (ESD) at -1000 V, -2000 V, -3000 V, -4000 V and -5000 V. The electrical performances and optical performances of samples were measured before and after ESD test. The LEDs stressed at -1000 V, -2000 V and -3000 V showed a soft breakdown due to the generation of defect inside the chip and LEDs stressed at -4000V and -5000V showed a thermal breakdown. The thermal breakdown made temperature rise rapidly and formed a melting channel, which caused the damage of the LED. Though the electrical performances and optical performances of LEDs stressed at -1000 V, -2000 V and -3000 V did not show conspicuous degradation, the damage induced by ESD affect the reliability of LEDs.