Figure 1: Scrape off any solder
mask or coating from the ends of
the remaining circuits. |
| 1. |
Clean the area.
|
| |
| 2. |
Remove the damaged section of circuit using
the knife. The damaged circuit should be trimmed
back to a point where the circuit still has
a good bond to the PC board surface.
|
| |
| |
Note
Heat can be applied to the damaged
circuit using a soldering iron to allow the circuit
to be removed more easily.
|
| |
| 3. |
Use a knife and scrape off any
solder mask or coating from the ends of the remaining
circuit. (See Figure 1). |
| |
| 4. |
Remove all loose material. Clean
the area. |
| |
| 5. |
Apply a small amount of liquid
flux to the ends of the remaining circuit. Tin the
exposed end of each circuit using solder and a soldering
iron |
| |
| 6. |
Clean the area. |
|
| |
|
Figure 2: Lap solder the wire to one
end of the circuit on the circuit board surface.
..
|
| 7. |
Select a wire to match the width
and thickness of the circuit to be replaced. Cut
a length approximately as needed. See Table 1 for
Solid Wire Equivalents. |
| |
|
Table 1 - Solid Wire Equivalents
Conductor Width
2 oz. Copper |
Equivalent Solid
Wire Diameter |
| .010" (0.25 mm) |
#34, .006" (0.15 mm) |
| .015" (0.38 mm) |
#32, .008" (0.20 mm) |
| .020" (0.50 mm) |
#31, .009" (0.23 mm) |
| .031" (0.78 mm) |
#29, .011" (0.28 mm) |
| .082" (2.08 mm) |
#26, .018" (0.46 mm) |
| .125" (3.18 mm) |
#23, .023" (0.58 mm) |
| When using
solid wire to repair a conductor, there
should be no reduction in the cross sectional
area. |
|
| |
|
| 8. |
Strip the wire and tin the ends
if needed. Non insulated wire may be used for short
repairs if conductors are not crossed. |
| |
|
| 9. |
Clean the wire. |
| |
|
| 10. |
If the wire is long or has bends,
one end may be soldered prior to forming the new
shape. Place the wire in position. The wire should
overlap the existing circuit a minimum of 2 times
the circuit width. The wire may be held in place
with Kapton tape during soldering. |
| |
|
| |
Note
If the configuration permits, the overlap
solder joint connection should be a minimum of 3.00
mm (0.125") from the related termination. This gap
will minimize the possibility of simultaneous reflow
during soldering operations. Refer to 7.1 Soldering
Basics. |
| |
|
| 11. |
Apply a small amount of liquid
flux to the overlap joint. |
| |
|
| 12. |
Lap solder the wire to one end
of the circuit on the circuit board surface. Make
sure the wire is properly aligned. (See Figure 2). |
| |
|
|
Figure 3: Form wire using a Wire Guide
|
| 13. |
Bend the wire as needed to match
the shape of the missing circuit. (See Figure 3). |
| |
Note
A Wire Guide can be used to form the
wire as needed. |
|
Figure 4: Form the final shape of
the wire and solder in place.
|
| 14.
|
Lap solder the other wire
end to the remaining circuit on the circuit board
surface using solder and a soldering iron. Make
sure the wire is properly aligned. (See Figure 4). |
| |
|
| 15. |
Remove any Kapton tape and clean
the area. |
| |
|
| |
Note
It may be necessary to encapsulate the
solder joint connection if electrical spacing is
reduced or the connection is beneath a component.
|
|
Figure 5: Bond the wires to the
surface with adhesive or Tape Dots.
|
| 16. |
If desired bond the wire to the
circuit board surface with adhesive, epoxy or Tape
Dots. (See Figure 5). Refer to Procedure 6.1. |
| |
|
| |
Caution
Some components may be
sensitive to high temperature. |
| |
|
| 17. |
Cure the epoxy per Procedure 2.7
Epoxy Mixing and Handling. |
| |
|
| 18. |
After the epoxy has cured clean
the area. |
| |
|
|
Evaluation |
| |
|
| 1. |
Visual examination for alignment
and overlap of wire. |
| |
|
| 2. |
Electrical tests as applicable. |
|
