DFM and DFA for PCBs

A board that works on the bench can still be expensive or unreliable to build. PCB DFM covers fabrication: trace and space widths, drill sizes, annular rings, copper balance and panelization within the fabricator's standard capabilities. DFA covers assembly: component spacing and orientation, accurate footprints (land patterns), fiducial marks, avoiding parts that need hand soldering, and keeping the assembly process simple.

Staying inside a factory's standard capabilities keeps cost and yield predictable. Every advanced feature (microvias, very fine pitch, unusual materials) narrows the pool of suppliers and raises cost.

Most contract manufacturers will run a DFM check on your files before a build. Treat its findings as real issues and resolve each one.