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.| Procedure References | |
| 1-0 | 1.0 Foreword |
| 2-1 | 2.1 Handling Electronic Assemblies |
| 2-2 | 2.2 Cleaning Procedures |
| 2-5 | 2.5 Baking and Preheating |
| 2-7 | 2.7 Epoxy Mixing and Handling |
Tools and Materials
Clear, superior strength epoxy in two-compartment plastic packages. |
General purpose cleaner for removing contamination. |
Disposable brushes for solvent cleaning and application of coatings. |
One part, semi-paste ink used to tint the color of epoxy and for direct printing on circuit board surfaces. |
Sturdy rack for PCBs used for rework and positioning. |
Swabs for use with solvents and application of color agents and epoxies. |
High temperature polyimide tape discs, .50" diameter. |
A must-have tool for precise cutting, scraping and trimming. |
Sharp probes for dispensing adhesive and positioning small objects. |
General purpose oven for drying, baking and curing epoxies. |
Nine precision-crafted tools for detailed circuit board work. |
Sharp dental-style probe for manipulating small objects and removal of debris. |
Hardened stainless steel tip for scraping solder mask and removing defects. |
Polypropylene syringe barrels with stainless steel dispensing tips. |
Multiple sizes and tip configurations of tweezers for various small parts handling needs. |
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
Lifted Conductor Repair, Epoxy Method
Apply a small amount of epoxy under the entire length of the lifted circuit.
Completed repair.
