IPC 7711A - 第230页
EVALUATION 1. Visual examination and tape test per IPC-TM-650, Test Method 2.4.1. 2. Electrical tests as applicable. NOTES IPC-7721A Number: 4.1.1 Revision: Date: 2/98 Subject: Lifted Conductor Repair , Epoxy Seal Method…
OUTLINE
This method is used to rebond a lifted conductor. Liquid epoxy is inserted under and
around the conductor to bond it back down to the printed wiring board surface.
CAUTION
This method should not be used to rebond a conductor that has been stretched or
damaged.
REFERENCES
2.1 Handling Electronic Assemblies
2.2 Cleaning
2.5 Baking and Preheating
2.6 Epoxy Mixing and Handling
TOOLS AND MATERIALS
Cleaner
Cleaning Wipes
Epoxy
Heat Lamp or Oven
Knife
Pick
PROCEDURE
1. Clean the area.
2. Remove any obstructions that prevent the lifted conductor from making contact
with the base board surface.
CAUTION
Be careful while cleaning and removing all obstructions, not to stretch or dam-
age the lifted conductor.
3. Clean the area.
4. Mix the epoxy.
5. Carefully apply a small amount of epoxy under the entire length of the lifted
conductor. The tip of a knife may be used to apply the epoxy. (See Figure 1.)
6. Press the lifted conductor down into the epoxy and into contact with the base
board material.
7. Apply additional epoxy to the surface of the lifted conductor and to all sides as
needed.
8. Cure the epoxy per the manufacturer’s instructions.
CAUTION
Some components may be sensitive to high temperature.
9. Apply surface coating to match prior coating as required.
Figure 1 Apply a small amount of
epoxy under the lifted conductor.
Figure 2 Completed repair.
7721A
Repair and
Modification of
Printed Boards and
Electronic Assemblies
Revision:
Date: 2/98
Lifted Conductor Repair,
Epoxy Seal Method
Number: 4.1.1
Product Class: R, F
Skill Level: Intermediated
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.
Page1of2
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---
EVALUATION
1. Visual examination and tape test per IPC-TM-650, Test Method 2.4.1.
2. Electrical tests as applicable.
NOTES
IPC-7721A
Number: 4.1.1
Revision:
Date: 2/98
Subject: Lifted Conductor Repair, Epoxy Seal Method
Page2of2
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 re-bond a lifted conductor. Dry film epoxy is used to re-bond
the lifted conductor.
CAUTION
This method should not be used to re-bond a conductor that has been stretched or
damaged
REFERENCES
2.1 Handling Electronic Assemblies
2.2 Cleaning
2.5 Baking and Preheating
TOOLS & MATERIALS
Bonding Iron
Bonding System
Bonding Tips
Cleaner
Cleaner Wipes
Dry Film Epoxy
Polyimide Tape
Knife
Microscope
Scraper
Tweezers
PROCEDURE
1. Clean the area.
2. Remove any obstructions that prevent the lifted conductor from making contact
with the base board surface.
CAUTION
Be careful while cleaning and removing all obstructions, not to stretch or dam-
age the lifted conductor.
3. Clean the area.
4. Cut out a piece of dry film epoxy that closely matches the size of the lifted con-
ductor. Be careful not to contaminate the dry film epoxy with materials that
could reduce the bond strength. (See Figure 1.)
NOTE
Dry film epoxy thickness should be selected to meet the requirements of the
printed wiring board.
5. Place a piece of Polyimide tape over the lifted conductor. Leave the tape in
place during the bonding cycle. (See Figure 2.)
6. Position the printed wiring board so that it is flat and stable. Gently place the hot
bonding tip onto the tape covering the conductor. Apply pressure and heat per
equipment manufacturer’s recommendation. (See Figure 3.)
Figure 1 Place a piece of dry film
epoxy under lifted conductor.
Figure 2 Place tape over the lifted
conductor.
Figure 3 Bond the lifted conductor
using a bonding system.
Figure 4 Completed repair.
7721A
Repair and
Modification of
Printed Boards and
Electronic Assemblies
Revision:
Date: 2/98
Lifted Conductor Repair,
Film Adhesive Method
Number: 4.1.2
Product Class: R, F
Skill Level: Intermediate
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.
Page1of2
Copyright Association Connecting Electronics Industries
Provided by IHS under license with IPC
Not for Resale
No reproduction or networking permitted without license from IHS
--``,``,-`-`,,`,,`,`,,`---