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Detail level of footprints

Open hephaisto opened this issue 7 years ago • 3 comments

What should be part of a footprint apart from the functional parts? Ideas:

  • If #3 will not have a full outline, have the remaining outline in a documentation layer
  • Thick lines in the documentation layer from plastic to pad (representing wings)?
  • Keepout areas? I saw them a few times, what reasons are pro/con?

hephaisto avatar Apr 04 '18 21:04 hephaisto

:+1: for all three points.

Keepout areas? I saw them a few times, what reasons are pro/con?

They are useful to let the DRC check if the board can be automatically assembled. If two parts are too near (but still not touching) you can get problems when assembling. The DRC can detect overlapped keepout areas to avoid that.

The keepout area is called "Courtyard" in IPC-7351, which also describes how it should be drawn exactly.

ubruhin avatar Apr 04 '18 21:04 ubruhin

But the Courtyard sometimes depends on the concrete component, even if the footprint is generic, right?

dbrgn avatar Apr 04 '18 22:04 dbrgn

But the Courtyard sometimes depends on the concrete component, even if the footprint is generic, right?

I think it should be independent of the component. Of course it depends on the exact package, but that's fine because in LibrePCB we create a separate library element for each package anyway, so we can't use the same footprint for different packages (even if the land pattern would be the same).

ubruhin avatar Apr 04 '18 23:04 ubruhin