Outline
This method is used to rebond a lifted land. Liquid epoxy is inserted under and around the land to bond it back down to the circuit board surface.
Minimum Skill Level - Advanced
Recommended for technicians with soldering and component rework skills and exposure to most repair/rework procedures, but lacking extensive experience.Conformance Level - Medium
This procedure may have some variance with the physical character of the original and most likely varies with some of 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. |
Sturdy rack for PCBs used for rework and positioning. |
High temperature polyimide tape discs, .50" diameter. |
A must-have tool for precise cutting, scraping and trimming. |
General purpose oven for drying, baking and curing epoxies. |
Nine precision-crafted tools for detailed circuit board work. |
Training kit to practice circuit board repair skills prior to testing for certification. |
Hardened stainless steel tip for scraping solder mask and removing defects. |
Nonabrasive, low-linting wipes for cleanup. |
Procedure
Procedure
- Clean the area.
- Remove any obstructions that prevent the lifted land from making contact with the baseboard surface.
Caution: Be careful while cleaning and removing all obstructions, as not to stretch or damage the lifted land. - Mix the epoxy.
- Carefully apply a small amount of epoxy under the entire length of the lifted land. The tip of the knife or scraper may be used to apply the epoxy. (See Figure 1)
- Place a piece of High-Temperature Tape over the lifted land and press the land down into the epoxy and into contact with the base board material. (See Figure 2)
- Apply additional epoxy to the surface of the lifted land 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.
Note: Double sided and multilayer circuit Boards, may require an eyelet to restore the through connection. Refer to section 5.0 Plated Hole Procedures. - Carefully remove any excess epoxy 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.
- Install the proper component and solder in place.
Note: This method is used to repair lifted lands, but the repaired lands may not have an intermetallic 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. - Replace surface coating to match prior coating as required.
Evaluation
- Visual examination and tape test per IPC-TM-650 test method 2.4.1. (ANSI/IPC-FC-250A)
- Electrical tests as applicable.
Images
Lifted Land Repair, Epoxy Seal Method
Carefully apply a small amount of epoxy under the entire length of the lifted land.
Place high temperature tape over the lifted land.
Completed repair.
