Circuit Board Repair Guide > Conductor Repair Procedures > 4.4.1 How to Rebond a Lifted Land Using Liquid Epoxy

How to Rebond a Lifted Land Using Liquid Epoxy

Repair Circuit Boards | Repair SMT Pads | Repair BGA Pads | Repair Lands | Repair Edge Contacts
Repair a Conductor | Plated Hole Repair | Base Board Repair | Replace Solder Mask or Coatings

This repair procedure is used to rebond a lifted land using liquid circuit board epoxy. Liquid epoxy is inserted under and around the land to bond it back down to the printed circuit board surface.

IPC Acceptability References
IPC-A-600 2.0 Externally Observable Characteristics
IPC-A-610 10.0 Laminate Conditions

Related Procedure References
CTC 1.0 Foreword - Circuit Board Repair Guide
CTC 2.1 Handling Electronic Assemblies
CTC 2.2.1 How to Clean a Circuit Board
CTC 2.2.2 Cleaning Circuit Boards, Aqueous Batch Process
CTC 2.5 Baking and Preheating of Printed Circuit Boards
CTC 2.7 Epoxy Mixing and Handling
IPC7721 4.4.1 Lifted Land Repair, Epoxy Method

Tools and Materials
Cleaner
Epoxy
Knife
Oven
Scraper
Tape, Kapton
Wipes
 
Lifted land needs rebonding
Lifted Land

4.4.1 Lifted Land Repair, Epoxy Seal Method

Printed Board Type: R  |  Skill Level: Advanced  |  Conformance Level: Medium  |  Rev.: D  |  Rev. Date: Jul 7, 2000

Apply epoxy under lifted land

Figure 1: Carefully apply a small
amount of epoxy under the entire
length of the lifted land.


1. 
Clean the area.
 
2. 
Remove any obstructions that prevent the lifted land from making contact with the base board surface.
 
 
Caution
Be careful while cleaning and removing all obstructions not to stretch or damage the lifted land.
   
3.  Mix the epoxy.
   
4.  Carefully apply a small amount of epoxy under the entire length of the lifted land. The tip of the knife or scraper may be used to apply the epoxy. (See Figure 1).
Place Kapton tape over lifted land

Figure 2: Place Kapton tape over
the lifted land.


5.  Place a piece of Kapton tape over the lifted land and press the land down into the epoxy and into contact with the base board material. (See Figure 2).
   
6.  Apply additional epoxy to the surface of the lifted land and to all sides as needed.
   
7.  Cure the epoxy per Procedure 2.7 Epoxy Mixing and Handling.
   
  Caution
Some components may be sensitive to high temperatures.
   
  Note
Double sided and multilayer circuit boards may require an eyelet to restore the through connection. Refer to section 5.0 Plated Hole Procedures.
   
8. 
Carefully remove any excess epoxy inside the plated hole using a ball mill or drill bit. Turn the ball mill or drill bit by hand to prevent damage to the wall of the plated through hole.
   
9.  Install the proper component and solder in place.
   
 
Note
This method is used to repair lifted lands, but the repaired lands may not have an inter-metallic connection to the remaining plated hole. The solder joint of the replaced component will restore the integrity of the electrical connection or an eyelet or buss wire may be used. See Plated Hole Repair Procedures.
   
10. Replace surface coating to match prior coating as required.
   
Lifted land repair completed

Figure 3: Land repair completed.
Evaluation
   
1. 
Visual examination and tape test per IPC-TM-650 test method 2.4.1 (ANSI/IPC-FC-250A).
   
2.  Electrical tests as applicable.




Links to Related Products


Circuit board epoxy for ciruit repair  
Circuit Bond Kit 115-1322: Liquid circuit board epoxy
Circuit Bond Kit contains 10 packages of clear, low viscosity, superior strength epoxy ideal for circuit board use. The epoxy is precisely measured out into two-compartment plastic packages. This adhesive is easy to use and there's no measuring.

Color Agents for Circuit Boards
Matching epoxy to the color of the circuit board being repaired is easy when you use a color agent. Color agents may also be applied directly to the circuit board surface for color matching.



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