Circuit Board Repair Guide > Conductor Repair Procedures > 4.4.2 How to Rebond a Lifted Land Using Film Adhesive

How to Rebond a Lifted Land Using Film Adhesive

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 procedure is used to repair damaged and lifted lands using film adhesive. The lifted lands are repaired with dry film epoxy. They are re-bonded to the printed circuit board surface using a circuit bonding system or bonding iron.

Caution
It is essential that the board surface be extremely smooth and flat. If the base board is damaged see appropriate procedure.

 
Lifted land needs rebonding
Lifted Land
IPC Acceptability References
IPC-A-600 2.10 Dimensional Characteristics

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
IPC7721 4.4.2 Lifted Land Repair, Film Adhesive Method

Tools and Materials
Bonding Film (#115-2706)
Bonding Iron and Bonding Tips      
Circuit Bonding System (optional)     
Cleaner      
Knife
Microscope      
Scraper
Tape, Kapton      
Tweezers
Wipes

4.4.2 Lifted Land Repair, Film Adhesive Method

Printed Board Type: R/F  |  Skill Level: Advanced  |  Conformance Level: Medium  |  Rev.: E  |  Rev. Date: Mar 28, 2001

Cut Bonding Film to match area of lifted land

Figure 1: Cut out the appropriate
shape of Bonding Film material to match the area of the lifted land.


1.  Clean the area.
 
2. 
Remove any obstructions that prevent the lifted land from making contact with the base board material.
   
3. 
Use the surgical knife and scrape off any epoxy residue, contamination or burned material from the board surface.
   
4.  Clean the area.
   
5. 
Cut out a piece of bonding film that matches the area of the lifted land. Be careful not to contaminate the dry film epoxy with materials that could reduce the bond strength. (See Figure 1).
   
 
Note
Dry film adhesive thickness should be selected to meet the requirements of the PC Board.
   
6.  Place the dry film under the lifted land. (See Figure 1).
   
Place Kapton tape over lifted land

Figure 2: Place Kapton tape over
the lifted land.


7. 
Place a piece of Kapton tape over the lifted land and press the land down into contact with the adhesive film. (See Figure 2).
   
8.  Select a bonding tip with a shape to match the shape of the lifted land.
   
 
Note
The bonding tip should be as small as possible but should completely cover the entire surface of the new land.
Bond land down using Bonding System

Figure 3: Bond the land down
using a Bonding System or
Bonding Iron with appropriate
Bonding Tip.


9. 
Position the circuit board so that it is flat and stable. Gently place the hot bonding tip onto the tape covering the new land. Apply pressure as recommended in the manual of the repair system or repair kit for 5 seconds to tack the land in place. Carefully peel off the tape. (See Figure 3).
   
10.
Gently place the bonding tip directly onto the land. Apply pressure as recommended in the manual of the repair system or circuit board repair kit for an additional 30 seconds to fully bond the land. The bonding film is fully cured. After the bonding cycle remove the tape used for alignment. Carefully clean the area and inspect the land.
   
 
Note
Double sided and multilayer circuit boards may require an eyelet to restore the through connection. Refer to section 5.0 Plated Hole Procedures.
   
11.
Carefully remove any excess bonding film 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.
 
12. Install the proper component and solder in place.
   
 
Note
This method is used to repair a lifted land, but the repaired land 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.
 
13. Replace surface coating to match prior coating as required.
   
Evaluation
   
1. 
Visual examination and tape test per IPC-TM-650 test method 2.4.1 (ANCI/IPC-FC-250A).
   
2.  Electrical tests as applicable.




Links to Related Products


Circuit Bonding System bonds surface mount and BGA pads  
Circuit Bonding System 115-3118
The Circuit Bonding System is the best, calibrated system for bonding adhesive film backed circuits and is ideally suited for bonding small patterns including surface mount and BGA pads. This bonding press not only gives the operator better control over the bonding process, but also ensures optimal adhesion and repeatability. Includes a built-in calibration slide to maintain a regulated bonding force depending upon the circuit pattern size and shape. The digital temperature controller maintains a uniform temperature throughout the 30-second bonding cycle.

Bonding Tips
The Bonding Tips fit into the hand held Bonding Iron (part number 115-3102) and the Circuit Bonding System. The bottom machined surface of each Bonding Tip is used to apply heat and pressure to bond the adhesive backed replacement pads, edge contacts, and lands to the circuit board surface.



Copyright and Disclaimer Notice Copyright CircuitMedic, Haverhill, MA 01835 USA

Related Items
Conductor Repair | PCB Tracks | Circuit Frames | Prototyping Boards | Surface Mount Resistor Kits | Surface Mount Capacitor Kits