A research on the reliability of light-emitting diode based on analyzing of chip image

Abstract

Abstract. This paper proposes a new method for studying the reliability of high-power light-emitting diode (LED) by analyzing chip images taken from a batch of LEDs which are selected to conduct the accelerated aging test lasting for 1400 hours. To exclude the disturbance of electrode in these images, an image processing algorithm based on projection is used to extract the interested section. An index called "dark point" which is related to non-radiative combination to describe the reliability of LED is proposed. The method is based on analyzing the variation trends of dark points in the extracted section of these images. The results show that the proportion of the dark point increases with aging time increasing. The lifetime of LED with higher increasing rate is shorter. Based on the increasing rate of dark point, the lifetime of the chip can be predicted in an easier way.