4.1.1 Lifted Conductor Repair, Epoxy Method

Outline

This method is used to rebond a lifted circuit. Liquid epoxy is inserted under and around the circuit to bond it back down to the circuit board surface.

Caution: This method should not be used to rebond a circuit 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.

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


Procedure References
1.0	Foreword
2.1	Handling Electronic Assemblies
2.2	Cleaning
2.5	Baking And Preheating
2.7	Epoxy Mixing and Handling
IPC7721 4.1.1	Lifted Conductor Repair, Epoxy Seal Method

Tools, Materials and Supplies

Circuit Bond Epoxy
Clear, superior strength epoxy in two-compartment plastic packages.

Flex-Rack PCB Holder
Sturdy rack for PCBs used for rework and positioning.

Cleaning Brushes
Disposable brushes for solvent cleaning and application of coatings.

Color Agents
One part, semi-paste ink used to tint the color of epoxy and for direct printing on circuit board surfaces.

Cleaner
General purpose cleaner for removing contamination.

Foam Swab, Small
Swabs for use with solvents and application of color agents and epoxies.

High Temp Tape Discs
High temperature polyimide tape discs, .50" diameter.

Knife with #16 Blades
A must-have tool for precise cutting, scraping and trimming.

Micro Probes
Sharp probes for dispensing adhesive and positioning small objects.

Oven
General purpose oven for drying, baking and curing epoxies.

Precision Tool Set
Nine precision-crafted tools for detailed circuit board work.

Probe
Sharp dental-style probe for manipulating small objects and removal of debris.

Scraper, Curved Tip
Hardened stainless steel tip for scraping solder mask and removing defects.

Syringes
Polypropylene syringe barrels with stainless steel dispensing tips.

Tweezers
Multiple sizes and tip configurations of tweezers for various small parts handling needs.

Wipes
Nonabrasive, low-linting wipes for cleanup.

Procedure

Clean the area.
Remove any obstructions that prevent the lifted circuit 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.
Mix the epoxy.
Carefully apply a small amount of epoxy under the entire length of the lifted circuit. The tip of a knife may be used to apply the epoxy. (See Figure 1)
Press the lifted circuit down into the epoxy and into contact with the base board material.
Apply additional epoxy to the surface of the lifted circuit and to all sides as needed. Cure the epoxy per Procedure 2.7 Epoxy Mixing and Handling.
Caution: Some components may be sensitive to high temperatures.
Apply surface coating to match prior coating as required.

Evaluation

Visual examination and tape test per IPC-TM-650 (ANSI/IPC-FC-250A) test method 2.4.1.
Electrical tests as applicable.

Images and Figures

Lifted Conductor Repair, Epoxy Method

Figure 1. Apply a small amount of epoxy under the entire length of the lifted circuit.

Figure 2. Completed repair.

4.1.1 Lifted Conductor Repair, Epoxy Method

Procedure to repair lifted conductors and circuits using liquid epoxy. Minimum Skill Level: Intermediate Conformance Level: High

Procedure to repair lifted conductors and circuits using liquid epoxy.

Minimum Skill Level: Intermediate
Conformance Level: High