trademarks of Cree, Inc.

XLamp XR-E LEds

10

notes

lumen maintenance Projections

Cree now uses standardized IeS LM-80-08 and TM-21-11 methods for collecting long-term data and extrapolating LeD

lumen maintenance. For information on the specific Lm-80 data sets available for this LED, refer to the public Lm-80

results document at www.cree.com/xlamp_app_notes/Lm80_results.

please read the XLamp Long-Term Lumen maintenance application note at www.cree.com/xlamp_app_notes/lumen_

maintenance for more details on Cree’s lumen maintenance testing and forecasting. please read the XLamp Thermal

management application note at www.cree.com/xlamp_app_notes/thermal_management for details on how thermal

design, ambient temperature, and drive current affect the LED junction temperature.

moisture sensitivity

XLamp LEDs are shipped in sealed, moisture-barrier bags (mBB) designed for long shelf life. If XLamp 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 derating table defines the maximum exposure time (in days) for an XLamp LED in

the listed humidity and temperature conditions. LEDs with exposure time longer than the time specified below must be

baked according to the baking conditions listed below.

Cree recommends keeping XLamp LEDs in their sealed moisture-barrier packaging until immediately prior to use. Cree

also recommends returning any unused LEDs to the resealable moisture-barrier bag and closing the bag immediately

after use.

temp.

maximum Percent relative humidity

30%

40%

50%

60%

70%

80%

90%

30 ºC

9

5

4

3

1

1

1

25 ºC

12

7

5

4

2

1

1

20 ºC

17

9

7

6

2

2

1

baking conditions

It is not necessary to bake all XLamp LEDs. only the LEDs that meet all of the following criteria must be baked:

1. LeDs that have been removed from the original mBB packaging.

2. LEDs that have been exposed to a humid environment longer than listed in the moisture Sensitivity section above.

3. LeDs that have not been soldered.

LEDs should be baked at 80 ºC 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 80 ºC. This baking operation resets the exposure time as

defined in the moisture Sensitivity section above.