TM 11-5820-922-40-1
6. Use a soldering iron to apply
15.
Encapsulate the worked area
solder to the eyelet and to the
with polyurethane coating by the
surrounding etch on both sides of
method described in paragraph 3-33.
the circuit card.
3-23. Repair of Raised or Unbended
Gold-Plated Copper Etch. Raised or
WARNING
unbended gold-plated copper etch
can be repaired by performing the
Isopropyl alcohol is flammable.
following steps:
Keep away from heat and open
flame. Vapors may be harmful.
1.
Determine the hole diameter
Use with adequate ventilation.
required for the new eyelet and
Avoid prolonged or repeated
select an eyelet of similar size.
breathing of vapor. Avoid eye
contact. Do not take internally.
WARNING
clean the circuit card with iso-
Drilling operations create
propyl alcohol.
metal chips which may enter
the eyes and cause serious
REPLACEMENT OF A LIFTED PAD.
injury. Eye protection is
Lifted pads (circular etch surround-
required.
ing either eyelets or plated-
through holes that have raised from
the board) can be replaced by per-
2.
If the hole is plated-
forming the following steps:
through, drill the hole to accom-
modate the new eyelet. Be careful
1. Remove the lifted pad. If
not to raise the etch while dril-
the hole has an eyelet, remove the
ling. If the hole has an eyelet,
eyelet first.
remove the defective eyelet.
3.
Use the eyelet press and dies
WARNING
to insert and form the new eyelet;
allow approximately 0.01 inch of
Toluene is flammable. Keep
etch to extend beyond the eyelet
away from heat and open flame.
rim. Allow clearance under both of
Vapors are harmful. Use only
the formed heads so that solder
with adequate ventilation.
flow under and around the formed
Avoid prolonged or repeated
heads will not be impaired.
breathing of vapor. Avoid con-
tact with skin and eyes. Do
not take internally. Comply
4.
Insert a round toothpick, or
with air pollution control
equivalent, in the eyelet hole to
rules concerning photochemi-
prevent solder from entering the
cally reactive solvents.
hole.
5. Apply soldering flux with a
2. Clean the area from which the
brush to the eyelet and surrounding
defective pad was removed with a
etch.
clean cloth moistened with toluene.
