Modifying Circuit Boards

Exposing copper

Test out your razor blade
- Use a razor blade by itself or one with a thin, pencil-like attachment
- Test if the tip is still sharp: using very litle force with your hand, does it slide easily over the surface of the soldermask or dig in?
  - You want a razor blade that easily scratches the surface. We want to press down on the razor blade with barely any force. If we have a dull razor blade, we'll have to press down hard.
Trace out the cut you are going to make
- Your first touches on the PCB with the razor blade should be extremely gentle. If you go hard the first time, the razor blade might not go in the direction you intended (if you're holding the blade at an angle, or for other reasons).
  - So very gently stroke the razor blade in a line where you're going to make a cut. You are trying to make a light channel in only the soldermask layer of the PCB so that later on, when you press harder to actually make a cut in the copper, your razor blade won't drift off course.