Method for rapidly evaluating reliability of LED (light-emitting diode) product under multi-stress condition

An evaluation method and reliability technology, applied in the field of rapid evaluation of multi-stress LED reliability, can solve the problems of impossibility to be accurate, the model cannot be applied with multiple stresses, and there is no satisfactory prediction method for the service life of LED, and achieves the key to improvement. technology, the effect of improving product quality

Active Publication Date: 2013-10-23
RESEARCH INSTITUTE OF TSINGHUA UNIVERSITY IN SHENZHEN
View PDF5 Cites 11 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

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

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for rapidly evaluating reliability of LED (light-emitting diode) product under multi-stress condition
  • Method for rapidly evaluating reliability of LED (light-emitting diode) product under multi-stress condition
  • Method for rapidly evaluating reliability of LED (light-emitting diode) product under multi-stress condition

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0015] In the most widely used Arrhenius model, where τ is the service time, τ r Is the lifetime at the reference temperature, Ea is the activation energy (eV), k is the Boltzmann constant (8.617×10 -5 eV / K), T is the absolute temperature (K), the temperature acceleration coefficient A T ,for:

[0016] A T = τ 2 τ 1 = e Ea k ( 1 T 2 - 1 T 1 )

[0017] The Arrhenius model assumes that only the accelerating stress of temperature has an effect. The Eyring model further considers multiple stresses such as current and humidity:

[0018] Assuming that only current acceleration is considered using the inverse power law, assuming only current acceleration stress:

[0019] τ﹦τ r I -N, I is the current, n is the current acceleration parameter,

[0020] Then the current acceleration coefficient A I for:

[0021] Also consider only humidity acceleration stress:

[0022] τ﹦τ r H -M

[0023] Humidity acceleration A H for: A ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

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 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 power l...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G01R31/26
Inventor 刘淮源刘岩敬刚胡益民张超陆兆隆张志甜陈进
Owner RESEARCH INSTITUTE OF TSINGHUA UNIVERSITY IN SHENZHEN
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products