| No. 4.4.1
Lifted Land Repair, Epoxy Method
OUTLINE
This method is used to rebond a lifted land. Liquid epoxy is inserted under and
around the land to bond it back down to the circuit board surface.
TOOLS & MATERIALS
Cleaner
Epoxy
Knife
Land Repair Kit
Oven
Scraper
Tape, Kapton
Wipes
PROCEDURE
- Clean the area.
- Remove any obstructions that prevent the lifted land from making contact
with the base board surface.
CAUTION
Be careful while cleaning and removing all obstructions, not to stretch or
damage the lifted land.
- Mix the epoxy.
- Carefully apply a small amount of epoxy under the entire length of the
lifted land. The tip of the knife or scraper may be used to apply the epoxy.
(See Figure 1).
- Place a piece of Kapton tape over the lifted land and press the land down
into the epoxy and into contact with the base board material. (See Figure 2).
- Apply additional epoxy to the surface of the lifted land and to all sides as
needed.
- Cure the epoxy per Procedure 2.7 Epoxy Mixing and Handling.
CAUTION
Some components may be sensitive to high temperatures.
NOTE
Double sided and multilayer circuit Boards, may require an eyelet to restore the
through connection. Refer to section 5.0 Plated Hole Procedures.
- Carefully remove any excess epoxy inside the plated hole using a ball mill
or drill bit. Turn the ball mill or drill bit by hand to prevent damage to the
wall of the plated through hole.
- Install the proper component and solder in place.
NOTE
This method is used to repair lifted lands, but the repaired lands may not have
an intermetallic connection to the remaining plated hole. The solder joint of
the replaced component will restore the integrity of the electrical connection
or an eyelet or buss wire may be used. See Plated Hole Repair Procedures.
- Replace surface coating to match prior coating as required.
EVALUATION
- Visual examination and tape test per IPC-TM-650 test method 2.4.1.
(ANSI/IPC-FC-250A)
- Electrical tests as applicable.
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Solutions Across the Board
TM
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Product Class R/F
Skill Level: Advanced
Conformance Level: Medium
Revision: D
Revision Date: Jul 7, 2000
Repair Service Charge
Lifted Land
Figure 1: Carefully apply a small amount of epoxy under the entire length
of the lifted land.
Figure 2: Place Kapton tape over the lifted land.
Figure 3: Completed repair.
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Tricks of the Trade
We prefer to use the film
adhesive method for bonding down lifted lands. Liquid epoxy is difficult to
control and may contaminate the plated hole. The adhesive film method eliminates
the potential problems of using liquid epoxy. If liquid epoxy is used, the epoxy
should have high temperature resistance to withstand subsequent soldering
operations. See Epoxy for more
information and a free sample.
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