Hello,
I have a problem with understanding what does the “Subtract solder mask from silkscreen” do (This is a check box inside File → Plot ). If I hover over it with a mouse it is written “Remove silk screen from areas without solder mask” so I would assume that if this box is checked, everywhere where there is no solder mask (soldering pads) there should be no silk screen. I assumed, that by checking this box you make sure that there is no silkscreen/text over pads, but this is not the case.
If I check gerber files of Silkscreen layer inside Gerbv program I get:
“Subtract solder mask from silkscreen” box checked (left):
“Subtract solder mask from silkscreen” box not checked(right):
Yes, indeed, that is the intention.
Is Gerbv the gerber viewer from Geda? KiCad uses a different color for each gerber layer and it looks like the right screenshot is a combination of several gerber layers.
You will also not see the difference as long as there are no silk screen texts overlapping with pads (or other areas without solder mask). To see the difference, just put some silkscreen text directly over a pad and then compare both outputs.
There seems to be a difference between Gerbv from Geda and Gerber viewer from KiCad. Silkscreen gerbers inside Gerber viewer look as expected (no difference between previously mentioned two cases of gerbers - checked box / unchecked box “Subtract solder mask from silkscreen” ).
On the other hand Silkscreen gerbers inside Gerbv are different from one another. If the previous screenshots are not clear I am adding new one with more perspective:
Your screenshots really are perplexing because KiCad doesn’t plot as a silk layer something which is seen in the left window (blue). Also if there’s a bug somewhere I’m more ready to believe it’s in Gerbv.
The easiest way to find out what happens would be to zip your project and attach it here. That way we could make experiments and check the design.
I checked with one of my boards: the blue pic is really what Gerbv sees from F-Silkscreen.gto if “Subtract soldermask…” is checked. I’ll double check that with JLCPCB. Stay tuned.
Thank you for the offer, but I believe you are right and there is some bug on Gerbv. I tried to view same gerber files with other gerber viewer programs and they all show the same silkscreen as KiCad.
Well, I had time at hand…
I checked with JLCPCB and they are happy with the silkscreen (says their viewer). So the culprit is Gerbv. I had some errors when loading the files as well there.
Ucamco makes the gerber plotters and is the maintainer of the Gerber format. Their reference viewer should be quite good, although I have very little personal experience with it.
