4.1.2 Lifted Conductor Repair, Film Adhesive Method
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.
Minimum Skill Level - Intermediate
Recommended for technicians with skills in basic soldering and component rework, but may be inexperienced in general repair/rework procedures.
Conformance Level - High
This procedure most closely duplicates the physical characteristics of the original, and most probably complies with all the functional, environmental and serviceability factors.
Microscope
Precision microscope with stand and lighting for work and inspection.
Micro Probes
Use to dispense a minute amount of adhesive and for micro-positioning of small objects.
Scraper
Hardened stainless steel tip for scraping solder mask and removing defects.
Tweezers
Multiple sizes and tip configurations of tweezers for various small parts handling needs.
Wipes
Nonabrasive, low-linting wipes for cleanup.
Images and Figures
Lifted Conductor
Figure 1: Cut out a piece of dry film epoxy and place it under the lifted conductor.
Figure 2: Place Kapton tape over the lifted conductor.
Figure 3: Bond the lifted conductor using a Bonding Iron.
Figure 4: Completed repair.
Procedure
Clean the area.
Remove any obstructions that prevent the lifted conductor from making contact with the baseboard surface.
Caution: Be careful while cleaning and removing all obstructions not to stretch or damage the lifted conductor.
Clean the area.
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.
Place the dry film epoxy under the lifted conductor. (See Figure 1)
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.
Place a piece of High-Temperature Tape over the lifted conductor. (See Figure 2)
Position the circuit board so that it is flat and stable. Gently place the hot bonding tip onto the 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.
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.
Replace surface coating to match prior coating as required.
Evaluation
Visual examination and tape test per IPC-TM-650 (ANCI/IPC-FC-250A) test method 2.4.1.
