AN1149-6 Lumileds Lighting, LLC, AN1149-6 Datasheet - Page 5

• Manufacturer Part Number: AN1149-6
• Description: Reliability Considerations for SuperFlux LEDs
• Manufacturer: Lumileds Lighting, LLC

Solder Heat Resistance Strife Test
SuperFlux LEDs have been designed so that
heat generated within the diode is quickly
dissipated out through the copper leads. This
thermally efficient design allows these LEDs to
be driven at higher power levels relative to other
LEDs, thus resulting in optimal optical
performance. However, when the leads are
immersed in solder, this design also allows heat
to conduct from the leads up into the active
area where the diode is located. Because
SuperFlux LEDs transfer heat from solder to die
much more quickly than other LEDs, it is
extremely important that recommended solder
profiles are followed during assembly to avoid
Note: These conditions EXCEED Lumileds
recommended soldering profiles.
Figure 6.3 Solder Heat Resistance Strife Test.
5
Table 6.2
Table 6.2 Recommended Validation Testing.
thermal stressing of the LEDs. Lumileds’
recommended soldering profiles are located in
Application Note 1149 2 Mechanical Design
Considerations for SuperFlux LEDs. Lumileds
uses the solder heat resistance strife test shown
in Figure 6.3 to verify that SuperFlux LEDs can
be soldered without damage. The temperature
cycles and hot functional test ensure detection of
latent damage or intermittent connections. This
test sequence was used to validate SuperFlux
LED performance. In addition, this test is
repeated regularly to monitor the performance
of SuperFlux LEDs.
Post Soldering 30X Visual
Inspection
Room Temperature
Operating Life
Temperature Cycle
Power Temperature Cycle
Recommended
Test
Refer to Application Note
1149 2 Mechanical
Design Considerations
for SuperFlux LEDs for a
description of the
procedure and
accept/reject criteria.
Ta = 25°C, 500 hours at
nominal drive conditions
& transfer times selected
based on thermal mass
of the assembly, 50
cycles
per minute transfer rate,
2 hour cycle, 5 minute
on/off, 50 cycles at
nominal drive conditions.
Or,
SAE J1889 OCT93:
to 5°C per minute
transfer rate, one hour
minimum dwell, powered
at nominal drive
conditions while warming
and hot, no power while
cooling and cold.
40
40
40
°C to 85°C
°C to 85°C
°C to 85°C
Parameters
Test
[1]
[1]
[1]
, dwell
, 3°C
, 0.6°C