6

Precautions:

Lead Forming:

•  The leads of an LEd lamp may be preformed or cut to 

length prior to insertion and soldering on PC board.

•  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.

•  If manual lead cutting is necessary, cut the leads after 

the soldering process. The solder connection forms a 

mechanical ground which 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:

•  Care must be taken during PCB assembly and soldering 

process to prevent damage to the LEd component. 

•  LEd component may be effectively hand soldered to 

PCB. However, it is only recommended under unavoid-

able circumstances such as rework. The closest manual 

soldering  distance  of  the  soldering  heat  source  (sol-

dering iron’s tip) to the body is 1.59mm. Soldering the 

LEd using soldering iron tip closer than 1.59mm might 

damage the LEd.

Note: 

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 re-calibrate the soldering 

profile again before loading a new type of PCB.

Avago Technologies LED configuration

 

Note: Electrical connection between bottom surface of LEd die and 

the lead frame is achieved through conductive paste.

1.59mm

•  ESd precaution must be properly applied on the sol-

dering station and personnel to prevent ESd damage 

to the LEd component that is ESd sensitive. do refer to 

Avago application note AN 1142 for details. The solder-

ing iron used should have grounded tip to ensure elec-

trostatic charge is properly grounded.

•  Recommended soldering condition:

Wave

Manual Solder

Dipping

Pre-heat temperature

105 °C Max.

-

Preheat time

60 sec Max

-

Peak temperature

250 °C Max.

260 °C Max.

dwell time

3 sec Max.

5 sec Max

Note: 

1.  Above  conditions  refers  to  measurement  with  thermocouple 

mounted at the bottom of PCB.

2.  It is recommended to use only bottom preheaters in order to reduce 

thermal stress experienced by LEd.

•  Wave  soldering  parameters  must  be  set  and  main-

tained  according  to  the  recommended  temperature 

and dwell time. Customer is advised to perform daily 

check on the soldering profile to ensure that it is always 

conforming to recommended soldering conditions.

•  Any  alignment  fixture  that  is  being  applied  during 

wave soldering should be loosely fitted and should not 

apply weight or force on LEd. Non metal material is rec-

ommended as it will absorb less heat during wave sol-

dering process.

•  At  elevated  temperature,  LEd  is  more  susceptible  to 

mechanical stress. Therefore, PCB must allowed to cool 

down to room temperature prior to handling, which in-

cludes removal of alignment fixture or pallet.

•  If PCB board contains both through hole (TH) LEd and 

other surface mount components, it is recommended 

that  surface  mount  components  be  soldered  on  the 

top side of the PCB. If surface mount need to be on the 

bottom  side,  these  components  should  be  soldered 

using reflow soldering prior to insertion the TH LEd.

•  Recommended  PC  board  plated  through  holes  (PTH) 

size for LEd component leads.

LED component

lead size

Diagonal

Plated through

hole diameter

0.45 x 0.45 mm

(0.018x 0.018 inch)

0.636 mm

(0.025 inch)

0.98 to 1.08 mm

(0.039 to 0.043 inch)

0.50 x 0.50 mm

(0.020x 0.020 inch)

0.707 mm

(0.028 inch)

1.05 to 1.15 mm

(0.041 to 0.045 inch)

•  Over-sizing the PTH can lead to twisted LEd after clinch-

ing. On the other hand under sizing the PTH can cause 

difficulty inserting the TH LEd.

 

Refer to Application Note 5334 for more information about soldering 

and handling of high brightness TH LEd lamps.

AlInGaP Device

CATHODE