Life Distribution and Reliability Analysis of High-Power Light Emitting Diodes under Thermal Environments  
Author Yao Hsu


Co-Author(s) Wen-Fang Wu; Ching-Cheng Zou


Abstract Finite element analysis (FEA) is frequently employed by researchers to investigate the mechanics and/or thermal behaviors of high-power light emitting diodes (HP LED). Unfortunately, after performing finite element analysis, only a few people continue to discuss the life and reliability of the LED. In the present study, a relationship between the junction temperature and the life of a LED is established first based on real test data. Finite element analysis is then employed to find the junction temperature of the LED. Afterwards, the life of the module is predicted based on the relationship mentioned above. To account for possible uncertainties, parameters such as convection coefficient and photoelectric conversion efficiency are considered random variables. Monte Carlo method for simulating samples of these random variables is employed in the finite element analysis and life prediction of the LED. An amount of lives indicating a random sample out of the studied LED are obtained, even under the same temperature and environmental condition. Statistical analysis is finally employed to find the life distribution and reliability of the LED. The result is very important to both LED manufacturers and consumers.


Keywords High-Power Light Emitting Diode, Junction Temperature, Parameter Uncertainty, Life Distribution, Reliability
    Article #:  20136
Proceedings of the 20th ISSAT International Conference on Reliability and Quality in Design
August 7-9, 2014 - Seattle, Washington, U.S.A.