IPC 7711A - 第294页
NOTES IPC-7721A Number: 4.7.1 Revision: Date: 2/98 Subject: Surface Mount Pad Repair , Epoxy Method P a g e4o f4 Copyright Association Connecting Electronics Industries Provided by IHS under license with IPC Not for Resa…
EVALUATION
1. Visual examination
2. Measurement of new pad width and spacing.
3. Electrical continuity measurement.
IPC-7721A
Number: 4.7.1
Revision:
Date: 2/98
Subject: Surface Mount Pad 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: 4.7.1
Revision:
Date: 2/98
Subject: Surface Mount Pad 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 surface mount pads with new dry film,
adhesive backed pads. The new pads are bonded to the printed wiring board sur-
face using a specially designed bonding press or bonding iron.
CAUTION
It is essential that the board surface be smooth and flat. If the base material is dam-
aged see appropriate procedure.
NOTE
This method uses commercially available replacement surface mount pads. The new
pads are fabricated from copper foil. 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
Cleaner
Epoxy
Heat Lamp
Polyimide Tape
Knife
Liquid Flux
Microscope
Oven
Replacement Surface
Mount Pads
Scraper
Solder
Soldering Iron
Tweezers
Wipes
PROCEDURE
1. Clean the area.
2. Remove the defective pad and a short length of the connecting circuit. (See
Figure 1.)
3. Use a knife and scrape off any epoxy residue, contamination or burned material
from the board surface.
CAUTION
Abrasion operations can generate electrostatic charges.
Figure 1 Remove the defective
surface mount pad and soldermask.
Figure 2 Scrape off solder resist.
Figure 3 Scrape off the adhesive
bonding film from solder joint area.
Figure 4 Cut out the new surface
mount pad.
7721A
Repair and
Modification of
Printed Boards and
Electronic Assemblies
Revision:
Date: 2/98
Surface Mount Pad
Repair, Film Adhesive
Method
Number: 4.7.2
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
--``,``,-`-`,,`,,`,`,,`---