IPC 7711A.pdf - 第236页
NOTES IPC-7721A Number: 4.2.1 Revision: A Date: 11/99 Subject: Conductor Repair , Foil Jumper , Epoxy Method P a g e4o f4 Copyright Association Connecting Electronics Industries Provided by IHS under license with IPC Not…
18. Coat the top and sides of the foil jumper with epoxy. The epoxy bonds the foil
jumper to the printed wiring board surface and insulates it. A wooden stick
sharpened at one end may be used to apply and spread the epoxy. (See Figure
6.)
19. Cure the epoxy per the manufacturers instructions.
CAUTION
Some components may be sensitive to high temperature.
20. Apply surface coating to match prior coating as required.
EVALUATION
1. Visual examination for alignment and overlap of foil jumper.
2. Visual examination of epoxy coating for texture and color match.
3. Electrical tests as applicable.
IPC-7721A
Number: 4.2.1
Revision: A
Date: 11/99
Subject: Conductor Repair, Foil Jumper, 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: 4.2.1
Revision: A
Date: 11/99
Subject: Conductor Repair, Foil Jumper, 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 or missing conductors on the printed wir-
ing board surface.
CAUTION
It is essential that the board surface be extremely smooth and flat. If the base board
is damaged see appropriate procedure.
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
Conductor Foil Jumpers
with Film Adhesive
Cleaner
Cleaner Wipes
Heat Lamp
Polyimide Tape
Knife
Liquid Flux
Microscope
Oven
Scraper
Solder
Soldering Iron
Tweezers
PROCEDURE
1. Clean the area.
2. Remove the damaged section of conductor using a knife. The damaged con-
ductor should be trimmed back to a point where the conductor still has a good
bond to the printed wiring board surface.
3. Use the knife and scrape off any epoxy residue, contamination or burned mate-
rial from the board surface.
4. Scrape off any solder resist or coating from the connecting conductor. (See Fig-
ure 1.)
5. Clean the area.
6. Apply a small amount of liquid flux to the connection area on the board surface
and tin with solder. Clean the area. The length of the overlap solder connection
should be a minimum of 2 times the conductor width.
Figure 1 Remove solder mask from
the connecting conductor.
Figure 2 Replacement conductors
with dry film adhesive backing.
Figure 3 Scrape off epoxy bonding
film.
Figure 4 Cut out the new conductor.
Cut from the plated side.
7721A
Repair and
Modification of
Printed Boards and
Electronic Assemblies
Revision:
Date: 2/98
Conductor Repair,
Foil Jumper, Film
Adhesive Method
Number: 4.2.2
Product Class: R, F, C
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
--``,``,-`-`,,`,,`,`,,`---