Circuit Board Repair and Rework Guide > 4.0 Conductor Procedures > 4.1.2 Lifted Conductor Repair, Film Adhesive Method

4.1.2 Lifted Conductor Repair, Film Adhesive Method

Printed Board Type: R/F | Skill Level: Intermediate | Conformance Level: High | Rev.: E | Rev. Mar 28, 2001

Outline

This method is used to repair damaged and lifted conductors. Dry film epoxy is used to rebond the lifted conductor.

Caution
This method should not be used to rebond a conductor that has been stretched or damaged.

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

Lifted Conductor

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
CTC	2.5	Baking and Preheating
IPC7721	4.1.2	Lifted Conductor Repair, Film Adhesive Method
Tools and Materials
Bonding Film Bonding Iron Bonding System Bonding Tips Cleaner Epoxy		Knife Microscope Scraper Tape, Kapton Tweezers Wipes

Procedure

Figure 1: Cut out a piece of dry film epoxy and place it under the lifted conductor.

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 damage the lifted conductor.

3.	Clean the area

4.	Cut out a piece of dry film epoxy that closely matches the size of the lifted conductor. 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 circuit board.

5.	Place the dry film epoxy under the lifted conductor. (See Figure 1).

6.	Select a bonding tip with a shape to match the shape of the lifted conductor

	Note The bonding tip should be as small as possible but should completely cover the entire surface of the conductor.

Figure 2: Place Kapton tape over the lifted conductor.

7.	Place a piece of Kapton tape over the lifted conductor. (See Figure 2).

Bond the lifted conductor using a Circuit Bonding System.

Figure 3: Bond the lifted conductor
using a Bonding System.

8.	Position the circuit board so that it is flat and stable. Gently place the hot bonding tip onto the Kapton tape covering the new conductor. Apply pressure as recommended in the manual of the repair system or repair kit for 5 seconds to tack the conductor in place. Carefully peel off the tape.

9.	Gently place the bonding tip directly onto the new conductor. Apply pressure as recommended in the manual of the repair system or repair kit for an additional 30 seconds to fully bond the conductor. The conductor is fully cured. Carefully clean the area and inspect the new conductor.

10.	Replace surface coating to match prior coating as required.

Figure 4: Completed repair.

Evaluation

1.	Visual examination and tape test per IPC-TM-650 (ANCI/IPC-FC-250A) test method 2.4.1.

2.	Electrical tests as applicable.