KiCad Board Outlines

Improved mechanical workflow
By Simon Hobbs |
(Updated: )
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I recently posted a video walk through of how I use board outlines and form factors as footprints in KiCad. It’s a useful approach I encourage you to try – especially when you are supporting many different designs. Simplifying and unifying designs can lead to network effects, allowing faster productivity growth with less complexity.

There are a few ways to make a board outline in KiCad:

  1. Drawing shapes directly with built-in tools
  2. Design the outline elsewhere, export to SVG or DXF and import as graphics
  3. Design the outline using either technique, save as a footprint instead of using it directly on the board.

Unless the board is a basic rectangle, I almost always make the board outline a footprint.

Benefits of Using a Board Outline Footprint

  • Promotes reuse, especially when mechanics or enclosures are involved
  • Allows common form factors to be stored in a shared library instead of relying on templates which get out of sync with minor changes.
  • Keeps outlines under version control, separate from layout
  • Prevents accidental changes—any modifications stand out clearly in version control
  • Footprint can be autoplaced like any other component
  • Supports compound designs (e.g., mounting holes, fiducials)
  • A board footprint has a part origin which can be used as a reference point and anchor for the grid and file origin of the layout.

Process

  1. Create a project specific footprint library. This keeps the board outline under the same repos version control. Duplicate the outline when it’s reused unless it’s an extremely common form factor.
  2. Draw or import the outline. I prefer to export an SVG from FreeCAD, where the board shape is parametric and well-defined.
  3. Group the outline and align it. Place the outline so the origin is the desired reference point. If you want the center of the drawing then you can use the placement tools to exactly center a group at the origin.
  4. Add features like mounting holes, fiducials, or logos. These become part of the footprint, so you’ll need to copy/paste them in. Group items to keep the footprint in one piece.
  5. Add drawing layer with key dimensions
  6. Place the footprint in your PCB layout. You can either enable “exclude from schematic” or add a matching symbol to your schematic.
  7. Place grid and drill origin at the footprint’s reference point. This also makes it easy to move the whole board and easily place the origin again which is especially useful if parts are aligned to the grid or you’re doing algorithmic placement.

Watch the Video

If you’re using this approach or have suggestions for improving it, let me know—I’d love to hear your workflow!