There was a time when LEDs generally had a maximum junction temperature of 85 degrees C, for both storage and operation.
This is no longer true. I can think of 3 examples, with one of them sadly no longer being manufactured (IIRC):
- Silicon carbide LEDs - the original blue LEDs developed by Cree. As far as I can tell, nobody makes these anymore, and Cree now uses silicon carbide in LEDs only as a substrate for gallium nitride and indium gallium nitride.
Silicon carbide blue LEDs appear to me to be close to bombproof, with the die having no problem with any temperature that epoxy encapsulant can. If someone would encapsulate them in silicone in a TO-18 package or a TO-18 package with no encapsulant (less efficient optically), they could probably easily take 200 degrees C, likely much more.
One SiC LED that still glowed after a lightning surge scorched the epoxy body encapsulating the die is shown in:
- There are modern high power LEDs able to take junction temperature as high as 150 degrees C for operation and 135 degrees C for storage for white, green and blue, 135 degrees C (for both storage and operation) for red, orange and amber-yellow. One example is Philips-Lumileds "Luxeon Rebel". Maximum external temperature when operating at 350 mA is 135 degrees C for white, green and blue, and 120 degrees C for red, orange and amber-yellow.
A datasheet supporting tolerance of such temperatures is at:
- Ordinary low power LEDs can now tolerate temperatures well above 85 degrees C. One example is Avago HLMP-ED31-SVOOO, and at least many of their other HLMP-ED*, HLMP-EH*, and HLMP-EL* LEDs. The maximum junction temperature is 130 degrees C for operating, and maximum case temperature is 100 degrees C for both operating and storage. The datasheet is at:
- Don Klipstein ( snipped-for-privacy@misty.com)