A test method for quickly evaluating the life of LED lighting products

Luminous flux attenuation is a key indicator for judging the life of LEDs . Energy Star (ES) in the United States defines the end of life of LED lighting products when the lumen maintenance rate of LED lighting products drops below 70%. Energy Star proposes to measure the lumen maintenance rate at 25℃±1℃ for 6000 hours and infer the life of LED lighting products based on this (the lumen maintenance rate for 6000 hours should not be less than 91.8%). Compared with the development of LED lighting technology and the speed of product replacement, the test time of 6000 hours (or more) is still too long and cannot meet the requirements of the rapid development of the industry.

　　Developing a fast reliability test method for life assessment of LED lighting products has become a critical issue for the industry. To address this problem, the National Key Laboratory of Semiconductor Lighting Joint Innovation spent two years researching and developed the "CSA020 LED Lighting Product Luminous Flux Output Accelerated Attenuation Test Method".

　　Based on the test methods of US Energy Star, LM-79, LM-80H and TM-21, CSA020 proposes a new accelerated attenuation test method based on the theoretical basis of "e-exponential model", "Arrhenius acceleration model" and "Poisson distribution": by increasing the ambient temperature during the test (to increase the LED junction temperature), the test time is further shortened. Under the test condition with a recommended maximum temperature of 55°C, data within 2000 hours can be used to replace the 6000 hours of data at room temperature required by the ES method. This method not only greatly shortens the traditional 6000-hour test time to within 2000 hours, but also maintains the quality and accuracy of the ES method. Fan Xuejun said that the feasibility and rationality of the accelerated attenuation test method adopted by the standard have not only been proved in theory, but also verified with actual test data of LED lighting fixtures.

　　At present, CSA020 has been discussed in more than 400 member units of the National Semiconductor Lighting Engineering Research and Industry Alliance and opinions from a wide range of companies in the industry have been solicited. It has been voted through by more than 80 formal member units, officially released, and gradually promoted and applied in domestic testing institutions. As a test method for quickly determining the life of LED lighting products, it will better support national fiscal