HLMP-3707, HLMP-3907, HLMP-3750, HLMP-3850, HLMP-3950, HLMP-3960,
HLMP-3390, HLMP-3490, HLMP-3590, HLMP-1340, HLMP-1440, HLMP-1540,
HLMP-K640 Data Sheet T-1 3/4 (5 mm), T-1 (3 mm), Ultra-Bright LED Lamps
Broadcom AV02-1556EN
13
Precautions
Lead Forming
Preform or cut the leads of an LED lamp to length prior
to insertion and soldering on PC board.
For better control, use proper tool to precisely form and
cut the leads to applicable length rather than doing it
manually.
If manual lead cutting is necessary, cut the leads after
the soldering process. The solder connection forms a
mechanical ground that prevents mechanical stress
due to lead cutting from traveling into LED package.
This is highly recommended for hand solder operation,
as the excess lead length also acts as small heat sink.
Soldering and Handling
Take care during PCB assembly and soldering process
to prevent damage to the LED component.
The LED component may be effectively hand soldered
to PCB. However, it is only recommended under
unavoidable circumstances, such as rework. The
closest manual soldering distance of the soldering heat
source (soldering iron’s tip) to the body is 1.59 mm.
Soldering the LED using soldering iron tip closer than
1.59 mm might damage the LED.
Apply proper ESD precaution on the soldering station
and by personnel to prevent ESD damage to the LED
component that is ESD sensitive. For details, refer to
Broadcom application note AN 1142. The soldering iron
used should have a grounded tip to ensure electrostatic
charge is properly grounded.
Recommended soldering conditions follow.
Set and maintain wave soldering parameters according
to the recommended temperature and dwell time.
Perform daily checks on the soldering profile to ensure
that it is always conforming to recommended soldering
conditions.
NOTE:
– PCBs 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, you should
recalibrate the soldering profile again before loading a new
type of PCB.
– Take extra precautions during wave soldering to ensure
that the maximum wave temperature does not exceed
250°C and the solder contact time does not exceeding 3s.
Over-stressing the LED during soldering process might
cause premature failure to the LED due to delamination.
Any alignment fixture that is being applied during wave
soldering should be loosely fitted and should not apply
weight or force on the LED. Nonmetal material is
recommended as it will absorb less heat during wave
soldering process.
At elevated temperature, the LED is more susceptible
to mechanical stress. Therefore, PCB must allowed to
cool down to room temperature prior to handling, which
includes removal of alignment fixture or pallet.
If PCB board contains both through hole (TH) LED and
other surface mount components, solder surface-mount
components on the top side of the PCB. If surface-
mount must be on the bottom side, solder these
components using reflow soldering prior to insertion the
TH LED.
Recommended PC board plated through holes (PTH)
size for LED component leads:
Over-sizing the PTH can lead to a twisted LED after it is
clinched. On the other hand, undersizing the PTH can
make inserting the TH LED difficult.
For more information about soldering and handling of TH
LED lamps, refer to application note AN5334.
Wave
Solderinga, b
a. These conditions refer to measurement with a thermocouple
mounted at the bottom of PCB.
b. To reduce thermal stress experienced by the LED, it is
recommended that you use only the bottom preheaters.
Manual Solder
Dipping
Pre-heat Temperature 105°C Max. —
Pre-heat Time 60 sec Max. —
Peak Temperature 250°C Max. 260°C Max.
Dwell Time 3 sec Max. 5 sec Max.
LED Component
Lead Size Diagonal
Plated Through-
Hole Diameter
Lead size (typ.) 0.45 × 0.45 mm
(0.018 × 0.018 in.)
0.636 mm
(0.025 in.)
0.98 to 1.08 mm
(0.039 to 0.043 in.)
Dambar shear-
off area (max.)
0.65 mm
(0.026 in.)
0.919 mm
(0.036 in.)
Lead size (typ.) 0.50 × 0.50 mm
(0.020 × 0.020 in.)
0.707 mm
(0.028 in.)
1.05 to 1.15 mm
(0.041 to 0.045 in.)
Dambar shear-
off area (max.)
0.70 mm
(0.028 in.)
0.99 mm
(0.039 in.)