4.4.2 Lifted Land Repair, Film Adhesive Method

This method is used to repair damaged and lifted lands. The lifted lands are repaired with dry film epoxy. They are re-bonded to the circuit board surface using a bonding press 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

Acceptability References
IPC-A-600	2.10	Dimensional Characteristics
Procedure References
CTC	1.0	Foreword
CTC	2.1	Handling Electronic Assemblies
CTC	2.2.1	Cleaning, Local
CTC	2.2.2	Cleaning, Aqueous Batch Process
IPC7721	4.4.2	Lifted Land Repair, Film Adhesive Method see procedure below

Tools and Materials
Ball Mills
Bonding Film
Bonding System
Bonding Tips
Cleaner
Knife
Land Repair Kit
Microscope
Scr aper
Tape, Kapton
Tweezers
Wipes

Procedure 4.4.2 Lifted Land Repair, Film Adhesive Method

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).

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.

Figure 3: Bond the land down using
a Bonding System.

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 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.