Gerber output and ordering: a checklist before sending for fabrication
DRC, Gerber and drill files, BOM, placement file. The things that are easy to miss on a first order.
1. DRC
Enter the manufacturer's minimums (trace width and spacing, drill size, annular ring) into the KiCad design rules first, then run DRC. The goal is zero errors.
| Item | Typical value at low-cost manufacturers |
|---|---|
| Minimum trace width/spacing | 0.127 mm (5 mil) |
| Minimum drill | 0.3 mm |
| Minimum annular ring | 0.13 mm |
2. Files to output
- Gerbers: one per layer (copper, solder mask, silkscreen, outline)
- Drill file: hole positions and sizes
- BOM: part numbers, values, packages, quantities, references (R1, C3 …)
- Placement file (CPL, pick and place): part positions and rotations, when you order assembly
3. Checks
- Open every layer again in a Gerber viewer. A missing outline is common.
- On the assembly service's screen, check part rotation (especially IC pin 1 and diode polarity).
- Put the board name, version and date on the silkscreen so boards are easy to tell apart later.
4. Order options
Board thickness (1.6 mm by default), copper weight (2 oz for high current), surface finish (HASL / ENIG), solder mask colour. With fine-pitch chips, ENIG's flat surface solders better.
Order only about five boards for the first prototype, and increase the quantity from the version after the problems are fixed.