9
Precautions:
Lead Forming
• The leads of an LED lamp may be preformed or cut to
length prior to insertion and soldering into PC board.
• If lead forming is required before soldering, care must
be taken to avoid any excessive mechanical stress
induced to LED package. Otherwise, cut the leads of
LED to length after soldering process at room
temperature. The solder joint formed will absorb the
mechanical stress of the lead cutting from traveling to
the LED chip die attach and wirebond.
• For better control, it is recommended to use proper
tool to precisely form and cut the leads to applicable
length rather than doing it manually.
Soldering Conditions
• Care must be taken during PCB assembly and soldering
process to prevent damage to LED component.
• The closest LED is allowed to solder on board is 1.59 mm
below the body (encapsulant epoxy) for those parts
without standoff.
• Recommended soldering conditions:
• Wave soldering parameter must be set and maintained
according to recommended temperature and dwell
time in the solder wave. Customer is advised to
periodically check on the soldering profile to ensure the
soldering profile used is always conforming to
recommended soldering condition.
Notes:
1. PCB with different size and design (component density)
will have different heat mass (heat capacity). This might
cause a change in temperature experienced by the board if
same wave soldering setting is used. So, it is recommended
to recalibrate the soldering profile again before loading a
new type of PCB.
2. Avago Technologies' high brightness LED are using high
efficiency LED die with single wire bond as shown below.
Customer is advised to take extra precaution during wave
soldering to ensure that the maximum wave temperature
is not exceeding 250°C. Overstressing the LED during
soldering process might cause premature failure to the LED
due to delamination.
Manual Solder
Wave Soldering Dipping
Pre-heat Temperature 105 °C Max. –
Pre-heat Time 30 sec Max. –
Peak Temperature 250 °C Max. 260 °C Max.
Dwell Time 3 sec Max. 5 sec Max.
Relative Light Output vs. Junction Temperature
0
1.0
RELATIVE LIGHT OUTPUT
(NORMALIZED AT T
J
= 25°C)
T
J
– JUNCTION TEMPERATURE – °C
-40
1.2
0.8
-20 0 20 40 60 80
0.2
0.4
0.6
GREEN
BLUE
