I intend to send a board to a PCB manufacturer and I am wondering how to mark unused components in the pick and place file. I'm using EAGLE and I saw that it includes all components in the file, but I do not want all of them to be mounted.
Can someone give me an advice on how it is better to proceed? Should I set those component's values to DNP (Do not place) so the manufacturer knows they shouldn't be mounted, and remove them from the BOM? Or should I manually remove the unused components from the pick and place file and BOM?
Best Answer
Personally I'd do the opposite of @CrossRoads, leave the reference designators in the BOM. If you set the value to DNI or DNP (or NM) with no other part numbers, all assembly houses will interpret this as meaning do not place.
If you want you can also add a column to your BOM which by true/false entry indicates whether a part is populated, however DNI/DNP should be enough.
The reason I'd suggest leaving the ref des in the BOM is that most assembly houses will examine your data and try to match up BOM entries to the silkscreen (even if you provide coordinate data). If they find parts on the silk that don't exist in the BOM, they may query you as to what should be done with those parts. If you mark them as unpopulated in the BOM, they have all the information they need without having to query it.