IPC 7711A - 第290页
NOTES IPC-7721A Number: 4.6.3 Revision: Date: 2/98 Subject: Edge Contact Repair , Plating Method P a g e6o f6 Copyright Association Connecting Electronics Industries Provided by IHS under license with IPC Not for Resale …
11. Thoroughly rinse the entire area with water.
12. Connect the gold plating probe to the power supply (+) or red jack.
13. Dip the plating probe into the gold plating solution. Wait a few seconds for the
solution to saturate the absorbent wrapping.
14. Swab the entire surface to be plated by brushing the surface with the saturated
plating probe. The plating probe should be moved back and forth briskly to pre-
vent burning and to provide even coverage. Swab the area for the time recom-
mended by the equipment manufacturer.
15. Thoroughly rinse the entire area with water.
16. Remove and discard all plating tape and thoroughly rinse the area with water.
Dry the area using a air sprayer or wipes.
17. Remove the wire or conductive paint used to buss the contacts.
CAUTION
Apply tape to protect the contacts from further contamination while removing
the buss connection.
16. Thoroughly rinse the entire area with deionized water or rinse the printed wiring
board in an aqueous water cleaning system.
EVALUATION
1. The rework area should be checked by measuring the thickness of the nickel
and gold to make sure they meet the minimum thickness requirement.
2. The plating bond may also be checked by doing a peel test using peel testing
tape.
3. Visually examine the rework area for color and luster.
IPC-7721A
Number: 4.6.3
Revision:
Date: 2/98
Subject: Edge Contact Repair, Plating Method
Page5of6
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: 4.6.3
Revision:
Date: 2/98
Subject: Edge Contact Repair, Plating Method
Page6of6
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 commercially
available replacement pads. The new pads are bonded to the printed wiring board
surface using liquid epoxy.
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
Buffer
Cleaner
Epoxy
Heat Lamp
Knife
Polyimide Tape
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 conductor. (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.
4. Scrape off any solder resist or coating from the connecting conductor. (See Fig-
ure 2.)
Figure 1 Remove pad.
Figure 2 Scrape off solder resist.
Figure 3 Cut out new pad.
Figure 4 Position pad using tape.
7721A
Repair and
Modification of
Printed Boards and
Electronic Assemblies
Revision:
Date: 2/98
Surface Mount Pad
Repair, Epoxy Method
Number: 4.7.1
Product Class: R, F, C
Skill Level: Advanced
Level of Conformance: Medium
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
--``,``,-`-`,,`,,`,`,,`---