What Is PCB Trace Solder Mask Opening?

May 15, 2026

PCB trace solder mask opening refers to removing the green solder mask (solder resist) from a portion of the PCB traces, exposing the copper underneath.

Steps:

1. Open your PCB and select Top Layer





2. Click on the Top Solder layer





3. Select the line tool from the toolbar





4. Draw the line on the trace where you want to remove the green solder mask, as shown in the figure





5. Press "3" to switch to 3D view to see the actual effect – the green solder mask is removed and the copper is exposed





6. For bottom layer solder mask opening, the process is similar – select Bottom Layer and then Bottom Solder layer