Lifetime Estimation of Ceramic Package Light-Emitting Diodes using Complex-Stress and Real-Time Monitoring  
Author Byungjin Ma

 
Co-Author(s) Jemin Kim; Sungsun Choi; Kwanhoon Lee

 
Abstract A complex-stress accelerated lifetime test (ALT) model, based on the combination of a thermal stress and an optical stress, was proposed and verified experimentally in order to reduce a testing time and enhance an accuracy of the lifetime estimation of light emitting diode (LED) packages. For verifying the proposed model, we developed a special ALT system capable of an in-situ monitoring of electrical, optical and thermal characteristics. The transient response of a voltage change in the LED chips was used to monitor the junction temperature as a measure of thermal stress on the lifetime. And the lifetimes of LED packages could be estimated according to the junction temperature and the relative optical power through the proposed complex-stress ALT.

 
Keywords LED, lifetime, ceramic package, accelerated lifetime test, junction temperature, real-time monitoring
   
    Article #:  19211
 
Proceedings of the 19th ISSAT International Conference on Reliability and Quality in Design
August 5-7, 2013 - Honolulu, Hawaii, U.S.A.