NIST welcomed delivery of the Vektrex-developed automated burn-in/light measurement system. White light LEDS from four different manufacturers have been sealed inside the special integrating sphere to begin 5 years of fully automated continuous testing. Each group of 120 devices will 480 3W white light LEDs from four different manufacturers will be tested at three different temperatures; 55C, 85C and 115C – using three different heat sink configurations. Some LEDs will remain illuminated and some will be switched on and off. The CAS-140 sealed inside the sphere will periodically measure each individual device light output, providing information about how luminance changes over time. A digital camera installed at the bottom of the sphere will constantly monitor the entire array, providing a time stamp marker when individual LEDs fail.
The Vektrex SpikeSafe DC / Continuous Pulse current source was selected for the reliability test. This current source provides accurate and reliable current. Developed for reliability applications, the SpikeSafe MTBF supports completing the test without unplanned maintenance.
For the light measurement, the SpikeSafe Performance Series current source was selected. Single pulse mode is employed for repeatable light measurements.
For more information about the NIST project please see: NIST LEDs Get a Life Sentence
For information about the presentation e see: CORM Website
For more information about Vektrex’s hemisphere based light measurement systems see: Light Measurement for High Power LEDs
