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.
• It is recommended that tooling made to precisely
form and cut the leads to length rather than rely upon
hand operation.
• 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.
• If necessary, use fixture to hold the LED component
in proper orientation with respect to the PCB during
soldering process.
• Proper handling is imperative to avoid excessive
thermal stresses to LED components when heated.
Therefore, the soldered PCB must be allowed to cool
to room temperature, 25°C, before handling.
• Special attention must be given to board fabrication,
solder masking, surface plating and lead holes size
and component orientation to assure solderability.
• Recommended PC board plated through hole sizes for
LED component leads:
LED Component
Lead Size
0.457 x 0.457 mm
(0.018 x 0.018 inch)
0.508 x 0.508 mm
(0.020 x 0.020 inch)
Diagonal
0.646 mm
(0.025 inch)
0.718 mm
(0.028 inch)
Plated Through
Hole Diameter
0.976 to 1.078 mm
(0.038 to 0.042 inch)
1.049 to 1.150 mm
(0.041 to 0.045 inch)
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:
Manual Solder
Dipping
–
–
260
°C
Max.
5 sec Max.
Pre-heat Temperature
Pre-heat Time
Peak Temperature
Dwell Time
Wave Soldering
105
°C
Max.
30 sec Max.
250
°C
Max.
3 sec Max.
Note:
Refer to application note AN1027 for more
information on soldering LED components.
TURBULENT WAVE
250
LAMINAR WAVE
HOT AIR KNIFE
BOTTOM SIDE
OF PC BOARD
TOP SIDE OF
PC BOARD
TEMPERATURE –
°C
200
150
FLUXING
CONVEYOR SPEED = 1.83 M/MIN (6 FT/MIN)
PREHEAT SETTING = 150°C (100°C PCB)
SOLDER WAVE TEMPERATURE = 245°C
AIR KNIFE AIR TEMPERATURE = 390°C
AIR KNIFE DISTANCE = 1.91 mm (0.25 IN.)
AIR KNIFE ANGLE = 40°
SOLDER: SN63; FLUX: RMA
NOTE: ALLOW FOR BOARDS TO BE
SUFFICIENTLY COOLED BEFORE EXERTING
MECHANICAL FORCE.
100
50
30
0
10
PREHEAT
20
30
40
50
60
70
80
90
100
TIME – SECONDS
Figure 9. Recommended wave soldering profile.
8
AVAGO [ AVAGO TECHNOLOGIES LIMITED ]
