Repairing a Damaged Pad on a PCB

Pads are typically damaged when devices are removed from PCBs. I am going to show you a way to repair damaged SMT land/trace combinations. The traces you cut from the circuit frame library are joined to existing printed circuit board traces.This process is part of the IPC 7721 which are the recommended procedures for repairing printed circuit boards. This one is found in 4.2.1 (Trace) and 4.7.1 (Pad). A complete kit can be purchased with all of the materials or you can get complete training on this and other processes or you can follow along with this "how to".

The materials you will need include:

Small c-clamps

Flux

Cleaning solvent

Microscope

Circuit Frame

Dental picks

Solder

Kapton™ tape

Soldering Iron

Knife

Wipes

ESD-safe cutting surface

Popsicle sticks

Orange sticks

Clean the damaged are with isopropyl alcohol and blow dry with canned or compressed air or damp dry with a lint free cloth.

Carefully cut away with an Exacto knife the damaged pad.

Remove any burned laminate from the area

Carefully remove solder mask from conductor using a dental pick

Clean the area using isopropyl alcohol and dry via compressed or canned air or a lint free cloth.

Using the correct type of solder alloy tin the conductor area in place where the new conductor will be attached

Select the new conductor from the circuit frame. Cut out with sharp small knife.

Using the right alloy of solder, tin new conductor area that will be overlapping old trace (about 2-3 conductor widths). Mix epoxy. I generally like to mix only a little at a time as the pot life is only 45 minutes or so. Bond to the PCB. Cure in open air or in an oven to accelerate the process per the manufacturers directions.

Hold the replacement conductor in placewith Kapton™ tape. Create the lap joint using the right solder alloy.

Hold the replacement pad/trace in place until cured. Remove the clamp. Clean with isopropyl alcohol and inspect. I also like to perform a quick electrical continuity check at this point. In some cases I even envelope the edges of the replacement pad/trace with solder mask or epoxy and cure so that it has extra mechanical strength.