DXF

DXF (Drawing Exchange Format) is a mechanical drawing file of lines, arcs, and named sheets that shops already know how to mill or plot.

A closed rectangular frame and a round hole, the kind of outline a mill can follow.

Package outlines, cavities, front-panel cuts, and microfluidic channels drawn by a mechanical engineer arrive as a .dxf. Chip editors store polygon loops on integer ticks. Mechanical files store floating inches or millimeters and keep the arcs. Layer names in the file are strings, not GDS numbers. A drawing may list 0, OUTLINE, and CUT, and those names have to be mapped by hand. A 1.6 millimeter board outline might be a closed polyline on the OUTLINE sheet.

Units are the other failure. Without a unit check, a 40 millimeter part becomes 40 micrometers, or the other way around. A file stored in inches and imported as millimeters grows by 25.4. After import, merge the outlines and snap them to the grid the process allows before trusting a width check. If the mechanical team still owns the outlines, keep their file as the source.

DXF is a cousin of Gerber. Boards still ship as plots and drills, and DXF does not take the place of those files. Chips still ship as GDSII or OASIS. Use DXF when the other team lives in mechanical CAD, then rebuild true layout geometry if the factory needs a stream. Imported arcs are not legal mask data on many mask paths, which expect fractured polygons. Convert the arcs, inspect the corners, and snap to the allowed grid.

Longer accounts are DXF from the mechanical world, Gerber is a plot language, and what is a layout.