As SSL products are being rapidly introduced into the market, there is a need to develop standard screening and testing protocols that can be performed quickly and provide data surrounding product lifetime and performance. These protocols, derived from standard industry tests, are known as ALTs (accelerated life tests) and can be performed in a timeframe of weeks to months instead of years. Accelerated testing utilizes a combination of elevated temperature and humidity conditions as well as electrical power cycling to control aging of the luminaires. In this study, we report on the findings of failure modes for two different luminaire products exposed to temperature-humidity ALTs. LEDs are typically considered the determining component for the rate of lumen depreciation. However, this study has shown that each luminaire component can independently or jointly influence system performance and reliability. Material choices, luminaire designs, and driver designs all have significant impacts on the system reliability of a product. From recent data, it is evident that the most common failure modes are not within the LED, but instead occur within resistors, capacitors, and other electrical components of the driver. Insights into failure modes and rates as a result of ALTs are reported with emphasis on component influence on overall system reliability.

Date Published: 18 September 2014
PDF: 9 pages
Proc. SPIE 9190, Thirteenth International Conference on Solid State Lighting, 919018 (18 September 2014); doi: 10.1117/12.2062243

Published in SPIE Proceedings Vol. 9190:
Thirteenth International Conference on Solid State Lighting
Matthew H. Kane; Jianzhong Jiao; Nikolaus Dietz; Jian-Jang Huang, Editor(s)