Datasheet
Copyright © 2008-2011 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree, the Cree logo and XLamp are registered trade-
marks of Cree, Inc.
9
XLAMP MC-E LEDS
NOTES
Lumen Maintenance Projections
Based on internal long-term reliability testing, Cree projects white XLamp MC-E LEDs to maintain an average of 70%
lumen maintenance after 50,000 hours, provided the LED junction temperature is maintained at or below 135°C and
each LED is operated with a constant current of up to 700 mA.
Please read the XLamp Long-Term Lumen Maintenance application note for more details on Cree’s lumen maintenance
testing and forecasting. Please read the XLamp Thermal Management application note for details on how thermal design,
ambient temperature, and drive current affect the LED junction temperature.
Moisture Sensitivity
XLamp MC-E LEDs are shipped in sealed, moisture-barri-
er bags (MBB) designed for long shelf life. If XLamp MC-E
LEDs are exposed to moist environments after opening the
MBB packaging but before soldering, damage to the LED
may occur during the soldering operation. The following de-
rating table denes the maximum exposure time (in days)
for an XLamp MC-E LED in the listed humidity and temperature conditions. LEDs with exposure time longer than the time
specied below must be baked according to the baking conditions listed below.
Baking Conditions
It is not necessary to bake all XLamp MC-E LEDs. Only the LEDs that meet all of the following criteria must be baked:
LEDs that have been removed from the original MBB packaging
LEDs that have been exposed to a humid environment longer than listed in the Moisture Sensitivity section above
LEDs that have not been soldered
LEDs should be baked at 80ºC for 24 hours. LEDs may be baked on the original reels. Remove LEDs from MBB packaging
before baking. Do not bake parts at temperatures higher than 80ºC. This baking operation resets the exposure time as
dened in the Moisture Sensitivity section above.
Storage Conditions
XLamp MC-E LEDs that have been removed from original MBB packaging but not soldered yet should be stored in a room
or cabinet that will maintain an atmosphere of 25 ±5ºC and no greater than 10% RH. For LEDs stored in these condi-
tions, storage time does not add to exposure time as dened in the above Moisture Sensitivity section.
Temperature
Maximum Percent Relative Humidity
30% 40% 50% 60% 70% 80% 90%
30ºC 9 5 4 3 1 1 1
25ºC 12 7 5 4 2 1 1
20ºC 17 9 7 6 2 2 1