IPC 7711A.pdf - 第272页
NOTES IPC-7721A Number: 4.5.1 Revision: Date: 2/98 Subject: Land Repair , Epoxy Method P a g e4o f4 Copyright Association Connecting Electronics Industries Provided by IHS under license with IPC Not for Resale No reprodu…
17. Install the proper component and solder in place.
NOTE
This method is used to replace a damaged or missing lands, but the new land
will not have an intermetallic connection to the remaining plated hole. The sol-
der joint of the replaced component will restore the integrity of the electrical
connection or an eyelet or clinched buss wire may be used. See Plated Hole
Repair Procedures.
18. Apply surface coating to match prior coating as required.
EVALUATION
1. Visual examination
2. Measurement of new pad width and spacing.
3. Electrical continuity measurement.
IPC-7721A
Number: 4.5.1
Revision:
Date: 2/98
Subject: Land Repair, Epoxy Method
Page3of4
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---
NOTES
IPC-7721A
Number: 4.5.1
Revision:
Date: 2/98
Subject: Land Repair, Epoxy Method
Page4of4
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---
OUTLINE
This method is used to replace damaged and lifted lands. The damaged lands are
replaced with new dry film, adhesive backed lands. The new lands are bonded to the
printed wiring board surface using a bonding press or bonding iron.
CAUTION
This method is used to replace a damaged or missing land, but the new land will 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. If a com-
ponent is not installed, a wire clinched to both sides of the printed wiring board may
be used.
CAUTION
It is essential that the board surface be smooth and flat. If the base board is dam-
aged see appropriate procedure.
NOTE
This method uses commercially available replacement lands. The new lands are fab-
ricated from copper foil and have a dry film adhesive coating on the back. They are
available in hundreds of sizes and shapes and are generally supplied solder plated.
If a special size or shape is needed they can be custom fabricated.
REFERENCES
2.1 Handling Electronic Assemblies
2.2 Cleaning
2.5 Baking and Preheating
2.6 Epoxy Mixing and Handling
TOOLS & MATERIALS
Bonding Iron
Bonding System
Bonding Tips
Buffer
Cleaner
Epoxy
Heat Lamp
Polyimide Tape
Knife
Liquid Flux
Microscope
Replacement Lands,
Adhesive Backed
Scraper
Solder
Soldering Iron
Tweezers
Wipes
Figure 1 Remove the defective land
and solder resist from the conductor.
Figure 2 Select a replacement land
that matches the missing land.
Figure 3 Scrape off the adhesive
bonding film from solder joint area.
Figure 4 Cut out the new land.
7721A
Repair and
Modification of
Printed Boards and
Electronic Assemblies
Revision:
Date: 2/98
Land Repair,
Film Adhesive Method
Number: 4.5.2
Product Class: R, F
Skill Level: Advanced
Level of Conformance: High
Material in this manual was voluntarily established by Technical Committees of IPC. This material is advisory only and its use
or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of this material.
Users are also wholly responsible for protecting themselves against all claims or liabilities for patent infringement. Equipment
referenced is for the convenience of the user and does not imply endorsement by IPC.
Page1of4
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---