Lumen degradation modeling of white-light LEDs in step stress accelerated degradation test

Jianlin Huang, Dušan S. Golubović, Sau Koh, Xiupeng Li, Xuejun Fan, Guo Qi Zhang

Research output: Contribution to journalArticleScientificpeer-review

44 Citations (Scopus)

Abstract

In this paper, lumen degradation is described by using a modified Brownian motion process for mid-power white-light LED packages, which were aged under step stress accelerated degradation test (SSADT). First, a SSADT model has been established based on the theory of equivalent accumulative damage. Then, a method was proposed to improve the accuracy of the parameter estimation by carefully modifying the estimator, which was proposed in the previous research. Experimental data show that parameters estimated by using SSADT model are very close to those estimated by using constant stress accelerated degradation test (CSADT) model, indicating the feasibility of the SSADT model. The experiment also indicates that SSADT can be used as an alternative to CSADT, as it enables comparable estimation accuracy, while using less testing time, a smaller sample size and less test capacity.
Original languageEnglish
Pages (from-to)152-159
Number of pages8
JournalReliability Engineering & System Safety
Volume154
DOIs
Publication statusPublished - 2016

Keywords

  • Accelerated test
  • Brownian motion
  • Light-emitting diodes
  • Step stress
  • Wiener process

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