Need to expose top side foil from below (3 replies)
I need to contact the underside of a surface-mount component. I want to open a 3/8"-diameter area from the back side of the PCB to make this contact. Has anyone tried this with a home work shop?
Drawing on the Solder Mask Layers
The ExpressPCB Classic layout program automatically blocks the solder mask from our library pads and
components. If you want to expose other areas, do so by drawing lines, arcs and rectangles on
the solder mask layers. To draw on one of these layers, it must first be displayed by checking
View top solder mask layer or View bottom solder mask layer in the Options dialog box. The
solder mask layers are displayed in reverse (solder mask is applied everywhere on the board, except where something is drawn).
In ExpressPCB Plus you can go to Colors and Visibility and select the Solder Mask layer you want to change. Then go to the Shapes category at the top and select the Solder Mask. Then select the drop down and select Keep Out Fill or Outline.