How to Prepare Gerber Files and BOM for PCB Assembly

The quality of your Gerber files and bill of materials (BOM) determines how fast your PCB assembly project moves and how accurate your quotation is. A complete package lets the factory review manufacturability and confirm scope in one pass, instead of emailing back and forth.

Gerber and fabrication files to include

• Copper layers (top, bottom, inner layers for multilayer)
• Solder mask and solder paste layers
• Silkscreen legends
• Board outline and drill files (Excellon)
• ODB++ output when your CAD tool supports it, which bundles the design into one file

BOM best practices

• Use exact manufacturer part numbers, not internal part numbers only
• Include reference designators that match the PCB layout
• List package types and values clearly
• Mark alternates and do-not-substitute parts explicitly
• Note any parts that are end-of-life or already purchased

CPL/XY placement data

Export the component placement file (centroid/XY) with the same coordinate origin as the Gerber. Include rotation and layer for each reference designator. This is what drives the pick-and-place program and the stencil.

At KGPCBA, the engineering review checks your files against the SMT process and confirms the component sourcing scope before quotation. Send your files and we will confirm the manufacturing route.