SMT Order Files: Checklist, Top 10 File Errors and Recovery Path

SMT Order File Checklist

For an SMT-only order (we solder your boards with our sourced or consigned parts), have these four files ready:

• Gerber + drill (RS-274X + Excellon) or ODB++ - the paste layer must be present for stencil cutting
• BOM - .xls/.csv with MPN, reference designators, quantity, package and value
• Centroid / pick-and-place - designator, X/Y in mm, rotation, side
• Assembly drawing - PDF for polarity, pin-1 and special instructions

Top 10 File Errors We See

1) BOM reference designators not matching the centroid file. 2) MPNs written as value-only (10k resistor without tolerance/package). 3) Rotation defined against a CAD library angle that differs from the actual footprint. 4) Bottom-side parts missing from the centroid. 5) Paste layer merged into the copper layer for large pads. 6) Drill files without plated/non-plated separation. 7) Trays or loose parts without a count sheet. 8) Obsolete MPNs discovered only at sourcing - no approved alternates given. 9) Board outline in the centroid file origin mismatch (mm vs mil). 10) Updated BOM sent after the order entered production.

Files Not Ready?

Upload what you have - the order enters engineering review, and we return a gap list with options: we can regenerate paste layers, rebuild centroids from Gerber silks (small extra fee), or source alternates for EOL parts. The worst move is waiting: start the SMT order and let engineering close the gaps with you.