File quality determines how fast a quote becomes a build. Export the right layers, use a clear naming convention and include the drill and centroid data.
Fabrication files
| File | Format / note |
|---|---|
| Gerber | RS-274X, one file per layer, units and format stated |
| NC drill | Excellon, separate plated and non-plated if applicable |
| Layer stack | PDF or drawing with material, thickness and copper weight |
| Fab drawing | Finish, mask colour, impedance, tolerances and special notes |
| Panelization | Drawing or array file if you require a specific panel |
Assembly files
| File | Format / note |
|---|---|
| BOM | Excel or CSV with reference designators, quantity, MPN and alternates |
| Centroid | CSV with ref, X, Y, rotation and side; origin clearly defined |
| Assembly drawing | Polarity, connectors, no-place parts and any hand-soldered items |
| Test specification | Nets, test points and functional procedure if applicable |
Common mistakes
- Mirrored bottom layersBottom copper and silkscreen must be exported in the correct orientation.
- Missing drill fileGerber alone does not define hole sizes or plating.
- Wrong centroid originThe centroid origin must match the Gerber origin, or placement will shift.
- Duplicate reference designatorsEvery ref must be unique; DNP parts should be marked, not deleted silently.
- No unitsState inches or millimetres in both Gerber and centroid files.
- Old revisionsName files with the board revision and confirm the BOM matches that revision.
A 30-second file check before sending saves days. If you are unsure, send the archive and we will tell you what is missing before quoting.
Frequently asked questions
Can you work from Altium, KiCad or Eagle files?
We prefer Gerber plus drill, but the native project helps resolve ambiguities. Send both if possible.
What centroid format do you need?
CSV with ref, X, Y, rotation and side. Include the units and the origin definition.
Do you need the BOM for fabrication only?
No, but it helps us confirm the board revision and identify any parts that affect the fab, such as press-fit connectors.