Hi, I have a question related to my understanding of the layers in KiCad and also related to manufacturing.
I don’t understand why when printing a PCB, the annular ring of the mounting hole is golden. In the 3D model of the PCB it shows golden as well. When I look at the footprint, I see that only F.Mask and B.Mask are active.
However, the regular pads of an SMD resistor/capacitor/etc are silver looking. The only difference I see is that the F.Paste is checked. Unchecking that layer of the pads will make them turn golden in the 3D rendering.
I want to print a PCB that has all the pads gold plated. What will happen if I un-check the F.Paste layer of all the pads? Is F.Paste only purpose for printing a stencil?
Yes, F.Paste is for creating solder paste stencils, which are used to apply solder paste evenly on pads. The 3d viewer assumes (by default) that solder paste is already applied on the appropriate areas and thus displays such pads silver instead of golden.
I don’t really understand what you want to accomplish, but if you want to manufacture a PCB with all SMT pads plated with gold, you need to specify “ENIG” (Electroless Nickel, Immersion Gold) when you order the board.
If PCB is gold plated then all opened (not covered with mask) copper is gold plated.
If PCB is not gold plated then all opened (not covered with mask) copper is not gold plated.
The process of gold plating simply works for the whole PCB.