How to repair missing circle pad

Question

I got a mouse and the pads are missing at the switch location. I tried to solder to the trace, but it didnt work. How can i save it ? Thanks!

Answer 1

Unfortunately, this is generally out of reach except in specialist professional settings due to the expense of track repair kits, the precision work required, and the cost-benefit of the whole operation vs replacement.

You can attempt this if you dare. At the very least, you will require a PCB track repair kit (e.g. CircuitMedic), microscope, scalpel, pick (may come in the pack), tweezers and a very steady hand.

Essentially the process is:

1. Remove damaged sections of track, plus any burnt material (if applicable).
2. Remove a small amount of coating from an undamaged section of track.
3. Choose a circular pad and trace section from the repair kit, and cut the track so that it will slightly overlap an undamaged section of track.
4. Mix the glue included with the repair kit and spread it thinly under the where the new track will go.
5. Place the replacement track sections on top of the glue.
6. Wait for the glue to dry (usually 12hrs or so).
7. Verify continuity between the undamaged trace and the circular trace.
8. (Optional, but recommended) Using a PCB green pen (not just a green pen, specifically one for PCBs), paint over the exposed copper track that you won't solder and allow it to dry.
9. Solder the replacement component in place, ensuring that there is good wetting between the component lead and the pads on both sides of the board.

In your case, the cost of the track repair kit will be many orders of magnitude more expensive than the mouse, and I'd just bodge it per Eugene's comment above.