A DFM check on the Gerbers catches fabrication issues such as spacing violations, insufficient annular rings, and solder mask slivers before they turn into a respin.
For assembly, the issues that hold orders usually sit elsewhere, in how the BOM, the placement file (CPL, or centroid file), and the footprints line up. The ones we see most often:
- Rotation offsets. EDA tools define zero orientation differently, so a correct layout can export a CPL with ICs or diodes rotated 90° or 180°.
- Footprint and part mismatches. The BOM part has a different package or pinout from the footprint. SOT-23 is the classic case, with several pin assignments in the same package.
- Designators that don’t match between the BOM and the CPL.
- Missing or ambiguous polarity marks on diodes, LEDs, and electrolytic capacitors.
When engineers find one of these, the order waits for your reply, so a query that arrives overnight can cost a full day. Whether the circuit itself is correct remains your responsibility.
Assembly follows the production file, which XPtronics engineers prepare from your files and the boards silkscreen. Confirm Parts Placement lets you review that file before assembly starts: check pin 1 on every IC, diode, and connector against the silkscreen, and the polarity of diodes, LEDs, and electrolytic capacitors.
