LED lighting product accelerated attenuation test method based on multilevel stepping stress

Abstract

The invention discloses an LED lighting product accelerated attenuation test method based on multilevel stepping stress. The method includes the following steps that first, the value of confidence and the number of samples are set; second, constant humidity stress, multiple stepping temperature stress levels and the total time of a test are set, and the step length time of all the temperature stress and measurement time nodes are set; third, the initial values of the luminous flux of target samples are measured, and luminous flux attenuation trajectory data of the target samples are obtained; fourth, an attenuation mechanism index test is performed; fifth, the pseudo failure life of the target samples is calculated; sixth, a distribution test is performed on the pseudo failure life, and a distribution function is selected; seventh, the distribution parameter of the distribution function is solved, and in combination with an Arrhenius temperature acceleration model, the reliability distribution function, the average life and the median life of the target samples are obtained. Through the method, the flexibility and the universality of a stepping stress test method applied to LED lighting products can be improved, the acceleration time is further shortened, and the accuracy of service evaluation of the accelerated test is improved.

Description

technical field [0001] The invention relates to an accelerated decay test technology of LED lighting products, in particular to a method for accelerated decay tests of LED lighting products based on multi-level step stress. Background technique [0002] LED (Light Emitting Diode) is favored because of its long life, no pollution, high efficiency and energy saving. In the field of general lighting, its wide application will be another revolution after the incandescent lamp. However, at this stage, there is a lack of feasible accelerated life test methods and standards for the reliability of LED lighting fixtures, which has become a bottleneck restricting LEDs from entering the general lighting field. [0003] The US Energy Star proposes to conduct at least 6000 hours of room temperature tests on the test samples, but such a requirement is difficult for companies trying to develop efficiently. In order to solve this problem, the invention with the patent publication number C...

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Problems solved by technology

[0004] However, on the one hand, when the accelerated test is carried out on LED products under too low stress level, some products, including LED packaging devices and LED lighting products, will be in the activation period, and the optical parameters will fluctuate for a period of time. That is, the luminous flux output is greater than the initial value, resulting in insufficient test data after the three-step stress acceleration test is completed to extrapolate product life information; on the other hand, due to the different stress and weather resistance of different products, there may also be 3 After the accelerated test of the step-by-step stress is completed, the luminous flux maintenance rate of the product has not decayed to the failure threshold L70, that is, the luminous flux has decayed to 70% of the initial value, which leads to the low accuracy of product life prediction, and the accuracy cannot be further determined. improve

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