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6.4 Component Lead Cutting and Lifting
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Outline
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.
Minimum Skill Level - Advanced
Recommended for technicians with soldering and component rework skills and exposure to most repair/rework procedures, but lacking extensive experience.
Conformance Level - Medium
This procedure may have some variance with the physical character of the original and most likely varies with some of the functional, environmental and serviceability factors.
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| Tools and Materials |
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Cleaner
General purpose cleaner for removing contamination. |
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Cutter and Pliers
Precision grade cutters and pliers. |
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Microscope
It is a challenge to undertake precision repair without a good microscope. |
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Mixing Picks
Unique mixing sticks have a paddle shape on one and sharp pick on the opposite end.
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Probe
Sharp dental style probe for manipulating small objects and removal of small debris.
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Soldering Iron, Solder and Flux
A well maintained soldering iron is a must at every tech bench. |
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Wipes
Nonabrasive, low-linting wipes for cleanup. |
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Images and Figures
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| Figure 1: Component Lead Cutting |
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| Figure 2: Specially designed cutters used to cut component leads. |
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| Figure 3: Place the cutter at the mid point in the lead and snip through to cut the lead. |
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| Figure 4: To ensure that the lead has been severed, the upper portion of the lead may be slightly lifted using a pick. |
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| Figure 5: If needed, solder both halves of the severed lead together. |
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| Figure 6: Place the cutter at the mid point in the lead and snip through to cut the lead. |
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| Figure 7: To ensure that the lead has been severed, the upper portion of the lead may be slightly lifted using a pick. |
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| Figure 8: If needed, solder both halves of the severed lead together. |
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| 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. |
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| Figure 10: Visually inspect, or electrically test, to ensure that the lead has been lifted. |
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| 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. |
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| Figure 1: Component Lead Cutting |
Note
Specially designed cutters are required when
cutting component leads.
Procedure - Lead Cutting, Plated
Through Hole Components
- 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.
- 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.
- 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.
- 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.
- If required, clean the flux residue and inspect.
Procedure - Lead Cutting, J Lead Components
- 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 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.
- 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.
- 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.
- If required, clean the flux residue and inspect.
Procedure - Lead Lifting, Standard Gull Wing Components
- Select the component lead that needs to be lifted. Apply a
soldering iron and solder braid to remove the excess solder from the joint.
- 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)
- Visually inspect, or electrically test, to ensure that the lead has been
lifted. See (Figure 10)
- If the lead needs to be reconnected, gently push the lead down until it
touches the pad and solder.
- If required, clean the flux residue and inspect.
Procedure - Lead Lifting, Fine Pitch Gull Wing Components
- Select the component lead that needs to be lifted. Apply a
soldering iron and solder braid to remove the excess solder from the joint.
- 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)
- Visually inspect, or electrically test, to ensure that the lead has been
lifted. See (Figure 12)
- If the lead needs to be reconnected, gently push the lead down until it
touches the pad and solder.
- If required, clean the flux residue and inspect.
Procedure for reference only.
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