TM 11-5820-922-40-1
5. Inspect the repair to be certain
that the damaged area has been bridged
copper or gold-plated copper conductors
by the solder.
(etch) bonded to the surface of the cir-
cuit cards can be damaged when mishan-
dled or when a component failure causes
current flow that exceeds the current-
6. Encapsulate the worked area by the
carrying limits of the etch. Certain
method described in paragraph 3-33.
types of damage to the etch can be
repaired by using the appropriate repair
techniques. Scratches or gouges on the
etch can be repaired by soldering. Sol-
Copper Etch. Broken or cut gold-plated
dering is also used to repair voids or
copper etch can be repaired by perform-
pinholes in the etch. Breaks or cuts in
ing the following steps:
the etch can be repaired by bridging the
defect with a new section of etch.
Lifted, raised, or unbonded etch can be
1. With an X-acto
knife, scrape the
repaired by pressing the etch against
polyurethane coating
from the area of
the card surface and encapsulating the
the circuit card to
be repaired. Be
defect with epoxy adhesive. Damaged
careful not to cause
further damage to
plated-through holes or eyelets are
the etch.
repaired by inserting and soldering an
eyelet. To repair damaged etch, per-
form the procedures of the following
2. Cut out a section approximately
paragraphs that apply to the type of
1/2 inch longer than the area to be
damage to be repaired.
repaired from a strip of gold-plated
copper ribbon (etch material).
Voided, or Pinholed Etch. Scratched,
gouged, voided, or pinholed etch faults
3. Tin the new piece of etch mate-
can be repaired by performing the fol-
rial; use solder sparingly.
lowing steps:
1. With an X-acto
knife, scrape the
4. Position the new etch material
polyurethane coating
from the area of
over the damaged area so that it over-
the circuit card to
be repaired. Be
laps by 1/8 inch and hold it in place
careful not to cause
further damage to
with an orange stick.
the etch.
5. Touch the soldering iron to one
2. Flatten any burrs that exist on
end of the new etch material until the
the defective area of the etch by using
solder flows to the damaged etch at that
the back of the recommended diagonal
end.
cutting pliers, or equivalent.
6. Use an orange stick to smooth out
3. Use a brush to apply soldering
the new etch material, work toward the
flux to the etch where defect exists.
unsoldered end; hold the new etch
material firmly in place with the orange
4. Use the soldering iron to apply
stick, cut off the surplus, and allow
solder to the defect. Use solder
approximately 1/8 inch for overlap.
sparingly.
