The typical failure modes of LED modules and luminaires contain different levels of failure modes, involving the LED package structure and process (see Table 1). LED in actual use, due to complex environment and packaging process limitations, resulting in degradation of package materials, phosphor degradation, metal electromigration, thermal stress caused by excessive local temperature, chip or silica layer delamination or gold wire breakage Etc., thereby affecting LED illumination and even causing failure of the entire LED. Moreover, the high temperature generated by the LED causes the luminous efficiency of the chip to be lowered, the light decay is accelerated, and the color shift is severely affected.
Due to the long life of LEDs, accelerated environmental testing is often used for reliability testing and evaluation. The acceleration test will simulate the application conditions or user requirements of the luminaire, so that various damage mechanisms can be studied more effectively, and a large amount of data is provided to study the structure, materials and processes of the LED to better improve the LED product. Some typical accelerated reliability tests (see Table 2).
However, the accelerated aging test is only one aspect of the research problem. The research on the prediction mechanism and method of LED life is still a difficult problem to be studied. Today's LED technology faces enormous challenges and opportunities. The company's goal is to ensure the long-term reliability of the product. For example, depending on the product, the range of life of LED applications ranges from 7,000 hours to 50,000 to 100,000 hours. This is quite challenging for an electronics company because their electronics are now only 2-3 years old. For 50,000 to 100,000 hours of SSL systems (including power drives), it is necessary to design reliability to meet the high requirements of the product.
At present, how to accurately predict the reliability of LED products through accelerated aging tests is still quite challenging. For the long-term reliability of LED products, attention should be paid to how to establish accelerated tests to reflect problems in the product. For understanding and predicting the reliability of macro systems, measurability is very challenging, mainly because reliability is a multidisciplinary issue and involves materials, design, manufacturing processes, testing and application conditions. Therefore, it is necessary to develop accelerated tests of LED lamps and lamps and performance test experiments for outdoor lighting fixtures, so that various destruction mechanisms of LEDs can be effectively studied.
It is reported that Philips is currently working on reliability testing standards to gain an in-depth understanding of LED and power drive failure mechanisms. There is reason to believe that in the near future there will be fast, reliable reliability test and standards for long-life LED lighting systems.
24V Charger,24V Ebike Charger,Electric Charger For Motor,24V Battery Charger
HuiZhou Superpower Technology Co.,Ltd. , https://www.spchargers.com