A rapid evaluation method for LED reliability under multiple stresses

Abstract

The invention discloses a method for rapidly evaluating the reliability of an LED (light-emitting diode) under a multi-stress condition. The method comprises the following steps that: S1, the lifespan Taur of the LED under specific conditions is measured, wherein the specific conditions refer to specific temperature T, electric current I and humidity H; and S2, the lifespan Tau of the LED is calculated by using the following formula according to fitting coefficients A, B, m and n, wherein Ea refers to activation energy (eV), k refers to the Boltzmann constant (8.617 multiplied by 10 minus 5eV / K), and T refers to absolute temperature (K). Two correction terms in the method fully considers the relevance among stresses, and dynamic correction is conducted by using an artificial neural network method on the basis of an original model. By using the method, the reliability of LED products can be rapidly and accurately evaluated by people in the industry, then defects possibly produced in the manufacturing process of the LED products can be found out and analyzed in a laboratory, and the key technology in the manufacturing process is improved so as to enhance the product quality.

Description

Technical field: [0001] The invention belongs to the field of semiconductor lighting and relates to a method for quickly evaluating the reliability of multi-stress LEDs. Background technique [0002] It is well known in the industry that LED products should have high reliability (many units advertise that their products can be used for 5 to 10 years), how to use the method of stress acceleration in the laboratory to quickly test the service life of LEDs is a top priority, and it is also a national The goal that scientists engaged in LED research in the world strive for. [0003] In order to reduce the test time, the accelerated life test scheme must be adopted. Before the accelerated life test, the relationship between the life under different stress conditions and the accelerated stress must be known first, that is, the ALT model must be established. [0004] At present, the main methods used in the industry to predict the life of LEDs are: [0005] 1) Use the inverse pow...

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Problems solved by technology

[0010] The above model must satisfy the theoretical hypothesis of Boltzmann constant and the theoretical hypothesis of transition state. The method cannot be accurate; in addition, the above model cannot be used for the calculation of multi-stress application, and in the actual physical working conditions, there is not only a single stress application, so there is currently no satisfactory prediction method for the service life of LEDs.

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