Accelerated testing method of LED luminaries

Abstract

With rapid development of lighting emitting diode (LED) market, more people are focusing on reliability testing method of LED luminaries system. However, it is difficult to use traditional reliability testing method for electronic products to assess LED luminaries with high reliability and long life. In this paper, reliability testing methods applied on LED, LED luminaries and other fields are reviewed shortly, and step stress accelerated life test (SSAL T) and step stress accelerated degradation test (SSADT) are selected for exploring reliability testing on commercial available LED systems. According to special characteristic of LED system and advantage of each method, both of methods are combined into one testing plan for evaluating system life. Proposed methods are also conducted on one thermal testing example by focused on commercial available LED bulb and lamp-cup systems. Explored results suggest that step stress accelerated test is an effective accelerated test method for LED luminaries. At the same time, there are still many challenging aspects for system reliability test, such as complicated failure mechanisms, Life gap among subsystems and also product manufacturers and lack of appropriate models to extrapolate. To assess the system reliability in future, an assessment procedure to subsystems is proposed by combining mentioned step stress accelerated test and system statistics analysis methodologies recommended in recent literature.

Failure causes and mechanisms of retrofit LED lamps

“…Each line represents the average trend of all the lamps from the same manufacturer stressed at the same external temperature. The reliability under typical operating conditions is high, a 6% drop after 4500 h in the worst case and almost no degradation for manufacturer C. These figures highlight a general improvement of the systems if compared to preliminary reports on the degradation of retrofit bulbs produced during previous iterations of the technological process [14], and can support additional research in order to obtain further improvements and widen the target market of these lighting engines.…”

A Novel High Power LED Module Design on Aluminum Board (COAB) by Packaging Multi-Die in both Series and Parallel

“…The LED has several advantages, such as low power dissipation and long term reliability. Thus it can replace the traditional light bulb for illumination [1][2]. But as the applying power to the LED is increased, the heat dissipation problem would reduce the efficiency dramatically [3][4].…”

Junction Temperature Prediction for LED Luminaires Based on a Subsystem-Separated Thermal Modeling Method

“…However, LED packages or LED modules are generally assembled with a heat sink and an optical structure. Thus, the implementation of the aforementioned T j measurement approaches for LED lamp systems with a complex geometry structure is impractical [13] unless the system is disassembled.…”