A mechanical drawing can look like a closed board outline while containing small gaps, duplicate segments, or several overlapping contours. Converting it into a PCB board shape without checking those entities can create an incorrect perimeter or omit an internal opening. Review the imported geometry before committing the shape.
Altium’s board-shape documentation describes using a closed imported outline and notes that internal cutouts are not automatically created by that operation. It also distinguishes shape-generation methods that follow different geometric boundaries. Confirm the specific conversion method being used.
Separate the manufacturing contour from the drawing
Identify which source layer contains the intended board perimeter and which contains dimensions, centerlines, construction geometry, or enclosure references. Import only the required contour into a controlled review layer. Keep the original mechanical source available for comparison.
Verify units, origin, and overall dimensions with known mechanical references. A shape can close perfectly at the wrong scale. Check an asymmetric feature to confirm orientation rather than relying only on width and height.
Inspect the contour entities
| Condition | Why it matters |
|---|---|
| Small gap between endpoints | The contour may not form the intended closed boundary |
| Duplicate or overlapping segment | Conversion may select or trace an unintended path |
| Internal opening | It needs an explicit board-cutout definition |
| Thick drawing line | Centerline and outer-edge interpretations may differ |
Resolve geometry in a way that preserves the intended mechanical dimensions. Do not close a gap by snapping endpoints arbitrarily when doing so changes a critical feature. Return ambiguous geometry to the mechanical owner for clarification. Where curved features are converted into many short segments, compare the resulting contour with the intended curve and required tolerance. A visually smooth preview is insufficient evidence that the approximation preserves a critical mating feature.
Verify the converted result
- Create the board shape from the reviewed contour.
- Define and inspect internal cutouts separately.
- Compare critical dimensions and radii with the source drawing.
- Check mounting and connector references against the new shape.
- Inspect the exported fabrication profile in an independent viewer.
Keep the imported drawing and the actual board shape visually distinguishable during review. Otherwise the original linework can conceal a conversion error: the screen may look right because the reference outline is still visible on top of the incorrect board.
Close the transfer with the mechanical source revision and the verified PCB shape. Recheck the profile whenever the source outline changes. The profile and cutout guide covers the manufacturing interpretation of those features after the geometry is established.
Move from reading to a build-ready project
Use the fabrication and assembly checklists to prepare drawings, production files and test requirements.
Open the DFM checklist