6.4 Component Lead Cutting and Lifting

This procedure covers the general guidelines for modifications that involve cutting and lifting component leads. Leads may be permanently cut or lifted due to engineering changes, or reconnected if done for testing purposes.


Procedure References
CTC 2.1 Handling Electronic Assemblies
CTC 2.2.1 Cleaning, Local
CTC 2.2.2 Cleaning, Aqueous Batch Process
CTC 6.1 Jumper Wires

Tools and Materials
Cleaner
Cleaning Wipes
Cutters
Flux
Microscope System
Pick
Soldering Iron with Tips
Solder
Wood Stick

Note:
Specially designed cutters are required when cutting component leads. 		  Component Lead Cutting

Figure 1: Component Lead Cutting


Cutters used to cut component leads.

Fig. 2: Specially designed cutters
used to cut component leads.


Place cutter at mid point in lead and snip through to cut lead.

Figure 3: Place the cutter at the mid point in the lead and snip through to
cut the lead.


To ensure lead has been severed, upper portion of lead may be slightly lifted using a pick.

Figure 4: To ensure that the lead
has been severed, the upper
portion of the lead may be slightly
lifted using a pick.
PROCEDURE - Lead Cutting, Plated Through Hole Components
   
1.
Select the component lead that needs to be cut and place the cutter in position. (See Figure 3). Place the cutter at the mid point in the lead and snip through to cut the lead.
 
2.
To ensure that the lead has been severed, the upper portion of the lead may be slightly lifted using a pick. Visually inspect, or electrically test, to ensure that the lead has been severed.
   
3.
If the lead needs to be reconnected, gently push the upper portion of the severed lead down until it touches the lower portion of the severed lead.
If needed, solder both halves of severed lead together.

Figure 5: If needed, solder both
halves of the severed lead together.


4. Solder both halves of the severed lead together. (See Figure 5).
 
 
Note
The lower portion of the lead may move during soldering since it is not anchored in position.
 
5.
If required, clean the flux residue and inspect.
Place cutter at mid point in lead and snip through to cut lead.

Figure 6: Place the cutter at the mid point in the lead and snip through to
cut the lead.
PROCEDURE - Lead Cutting, J Lead Components
   
1.    
Select the component lead that needs to be cut and place the cutter in position. (See Figure 6). Place the cutter at the mid point in the lead and snip through to cut the lead.
To ensure lead has been severed, upper portion of lead may be slightly lifted using pick.

Figure 7: To ensure that the lead has
been severed, the upper portion of
the lead may be slightly lifted using
a pick.


2.    
To ensure that the lead has been severed, the upper portion of the lead may be slightly lifted using a pick. (See Figure 7). Visually inspect, or electrically test, to ensure that the lead has been severed.
   
3.
If the lead needs to be reconnected, gently push the upper portion of the severed lead down until it touches the lower portion of the severed lead.
If needed, solder both halves of severed lead together.

Figure 8: If needed, solder both
halves of the severed lead together.
4.
Solder both halves of the severed lead together. (See Figure 8).
   
  Note
The lower portion of the lead may move during soldering since it is not anchored in position.
   
5. If required, clean the flux residue and inspect.
Place a pick behind component lead to be lifted.

Figure 9: Gently place a pick behind
the component lead to be lifted. Apply
a soldering iron tip to the foot of the component lead. Apply slight force
with the pick to lift the lead as the soldering iron reflows the joint.
PROCEDURE - Lead Lifting, Standard Gull Wing Components
   
1.
Select the component lead that needs to be lifted. Apply a soldering iron and solder braid to remove the excess solder from the joint.
 
2.
Gently place a pick behind the component lead to be lifted. Apply a soldering iron tip to the foot of the component lead. Apply slight force with the pick to lift the lead as the soldering iron reflows the joint. (See Figure 9).
Inspect to ensure lead has been lifted

Figure 10: Visually inspect, or
electrically test, to ensure that the
lead has been lifted.


3.
Visually inspect, or electrically test, to ensure that the lead has been lifted. (See Figure 10).
 
4.
If the lead needs to be reconnected, gently push the lead down until it touches the pad and solder.
   
5.
If required, clean the flux residue and inspect.
Place pick behind component to be lifted.

Figure 11: Gently place a pick behind the component lead to be lifted.
Apply a soldering iron tip to the foot
of the component lead. Apply slight
force with the pick to lift the lead as
the soldering iron reflows the joint.


PROCEDURE - Lead Lifting, Fine Pitch Gull Wing Components
   
1.
Select the component lead that needs to be lifted. Apply a soldering iron and solder braid to remove the excess solder from the joint.
 
2.
Gently place a pick behind the component lead to be lifted. Apply a soldering iron tip to the foot of the component lead. Apply slight force with the pick to lift the lead as the soldering iron reflows the joint. (See Figure 11).
Inspect to ensure that lead has been lifted.

Figure 12: Visually inspect, or
electrically test, to ensure that the
lead has been lifted.
3.
Visually inspect, or electrically test, to ensure that the lead has been lifted. (See Figure 12).
 
4.
If the lead needs to be reconnected, gently push the lead down until it touches the pad and solder.
  
5.
If required, clean the flux residue and inspect.


Related Items
HEI-MP4-FR Stereo Zoom Microscope Package | 6.1 Jumper Wires | 6.2.1 Jumper Wires, BGA Components, Circuit Track Method | 6.2.2 Jumper Wires, BGA Components, Through Board Method | 6.3 Component Modifications and Additions | 6.4 Component Lead Cutting and Lifting

6.4 Component Lead Cutting and Lifting