I have a board that has a “daughter” board that plugs into a 40 pin header. I need to place parts under this daughter board and I would like to see the outline of the daughter board on the main board while laying out the board without the DRC errors. I would also like to keep the outline of the daughter board (helps with alignment when installing the daughter board) when the board is fabricated. However, an outline at fabrication time is not 100% necessary.
If I make the outline of the daughter board on the front silkscreen, I get violations when a part crosses the outline of the board. Is there another layer I can use for the daughter board outline that will not create design rule violations?
How do I suppress the messages just for that part and that particular violation? Is this a special case I have to tell the company about that is making the board?
Click on the message and you’ll see the options. Since it’s just silkscreen crossing silkscreen, and silkscreen over copper will be removed anyway, I don’t see a manufacturing problem.
You could also shrink the outline lines, maybe to just the corners.
You can’t cross the beams when you’re hunting ghosts, but silkscreen lines on a PCB do not matter. The only issue I can think of is readability of text.
Note there is no DRC arrow where the two lines cross. I had to place those two lines over silkscreen lines of a footprint to force it to generate a DRC violation.
Every now and then I think about making a feature request for treating silkscreen text separately from other graphics on silkscreen. Other graphics crossing silkscreen text is a readability issue (It does not matter for manufacturing). I find DRC violations for graphic lines crossing each other a bit silly, but I can’t turn it off completely without also turning it off for text.
Edit: Oops, I thought it was stil about silkscreen lines over silkscreen lines. But after seeing Piotrs response, indeed silkscreen over pads is an issue, and KiCad can subtract silkscreen from the solder mask.
Manufacturers treat this in three different ways:
Some always stubtract silkscreen from pads, even if you do not want it.
Some print silkscreen over the pads, which leads to a lot of scraping with a knife if you want to salvage the PCB’s.
Some halt production and ask you what you want.
In the end, fixing it yourself before you send out gerbers will smooth the ordering proecess.
When generating gerbers you should have option to delete silk from pads (I have no KiCad here to check). If you do this than you will not have manufacturing issue.
If not then there is high chance manufacturer will do it for you.
And if neither you, neither he will do it you will have pads painted with silkscreen.
