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May, 2011 Page 1 of 13
Reliability of the DRAGON Product Family
Application Note
Introduction
This application note provides an overview
of the performance of the DRAGON product
family (in this case, LEDs without plastic
lenses) as well as a summary of the most
important customer-relevant LED data with
respect to its effect on LED lifetime.
In general, it should be noted that in spite of
the high reliability of LEDs, a high total or
system reliability can only be achieved if all
factors and parameters are taken into
consideration (see Application Note
"Reliability and Lifetime of LEDs").
A possible influence on the reliability of the
LED by the user is essentially specified by
the chosen operating conditions, by
consideration of the processing details, and
for high power LEDs such as the DRAGON
product family, for example, by the provision
of adequate thermal management.
DRAGON product family
The DRAGON product family was primarily
developed for applications which require
maximum light combined with low space
requirements and the highest demands on
lifetime.
Due to their performance and design,
DRAGON LEDs are suitable for diverse
areas of lighting and illumination technology,
ranging from general lighting to automotive
applications and the replacement of
miniature incandescent lamps.
Designed for high-volume production, they
can be processed with all established
populating techniques and mounted by
means of lead-free IR reflow soldering
techniques.
As with all other LEDs from OSRAM Opto
Semiconductors, the DRAGON product line
also fulfills current RoHS guidelines and
contains no lead or other hazardous
substances.
Construction and aging
mechanisms of DRAGON LEDs
The construction of the DRAGON product
family is based on a thermally-optimized
package design, consisting of a prefabri-
cated plastic package with an integrated
heat sink and connection contacts
(Figure 1).
An advantage of this design is that it permits
mutual exchangeability within the product
family, thus increasing customer flexibility
due to identical solder pad layouts.
A primary factor which influences the lifetime
of an LED is the temperature of the light-
emitting layer or junction temperature (T
j
)
with which the LED is driven in the
application.
