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发光二极管(light-emittingdiode,LED)作为正在兴起的固态冷光源具有效率高、寿命长、体积小、响应快、抗振、驱动电压低、绿色环保等特点,在照明光源、仪表指示等领域显示出较大的发展潜力.针对LED器件寿命在实际使用环境中应力影响因素复杂、加速寿命试验模型考虑的应力因素不全面以及LED器件寿命预测模型准确性低等问题,本文提出了一种LED器件多应力条件下寿命快速评估系统模型.该模型适用于各种工艺制造的不同结构的LED器件.以光效衰减30%为寿命依据,以环境温度、湿度和驱动电流为输入量、LED器件寿命为输出量,采用设计的自适应遗传算法确定被测器件的辨识参数.利用构建的加速寿命试验获得较高温度湿度电流应力下的少量样本数据,基于得到的样本数据辨识该模型的未知参数,获得了模型.在常温常湿常电流应力下,通过该模型进行了LED器件寿命预测.研究结果表明:在任意温度湿度电流应力下,提出的模型可以快速较精确地实现LED器件寿命预测;在常温常湿常电流应力下,基于提出的模型得到的LED器件寿命接近于LED行业平均技术水平的LED预期寿命;提出的模型应用于LED器件寿命可靠性测评具有实用性,并可继续拓展成为纳入更多应力的模型.
Light-emitting diodes (LEDs) are emerging as solid state light sources with high efficiency, long life, small volume, fast response, anti-vibration, low driving voltage and environmental protection, A great potential for development.Aiming at the problems that the life span of LED device is complicated in the actual use environment, the stress factors of accelerated life test model are not comprehensive and the accuracy of life prediction model of LED device is low, a LED device Multi-stress conditions, life-rapid assessment of the system model.The model is suitable for a variety of structures of different structures of LED devices.With the luminous efficiency of 30% of the decay on the basis of life, ambient temperature, humidity and drive current input, LED device life For the output, the designed adaptive genetic algorithm is used to determine the identification parameters of the device under test, a small amount of sample data under higher temperature and humidity current stress is obtained by the built accelerated life test, the unknown parameters of the model are identified based on the obtained sample data, Get the model.Under normal temperature and humidity, the current stress, through the model LED device life The results show that under any temperature and humidity current stress, the proposed model can quickly and accurately predict the lifetime of LED devices. Under the conditions of normal temperature, normal humidity and normal current stress, the lifetime of LED devices based on the proposed model is close to that of the LED industry The average technical level of LED life expectancy; the proposed model for the reliability of life assessment of LED devices has practicality, and can continue to expand into a model incorporating more stress.