What Files Are Required for PCB Assembly?

Start with One Released Revision

Before exporting files, identify the assembly revision and the build variant. If the BOM is updated after the layout export, recheck the fabrication and placement outputs rather than sending the files independently. A simple package note can identify the revision, build quantity, fitted options, and the contact responsible for engineering questions.

For example, a sensor board may have two connector options sharing one outline. Name the variant and mark the unfitted connector positions explicitly. Do not rely on the assembly team to infer the option from an email thread.

Give Each File a Clear Job

Gerber and drill files define the bare board. A BOM should identify manufacturer part numbers, quantities, and reference designators. The placement list records coordinates, board side, and rotation. An assembly drawing explains polarity and mechanical details that need a human-readable reference. These roles are complementary: one file should not be expected to replace the rest.

Separate customer-supplied parts from parts to be procured. Include approved alternatives and mark substitutions requiring approval. If a material decision is still open, describe the issue rather than inserting an unapproved part number as though it were released.

Include the Operations after Soldering

Firmware, programming instructions, and test procedures define work that cannot be inferred from the BOM. State the expected results and any fixtures or interfaces needed. If the prototype is only intended for bring-up, explain which checks you want completed before delivery and which you will perform yourself.

Finish with labeling, packaging, quantity, and the requested date. A complete package does not mean every detail must be decided before an inquiry; it means known requirements and open questions are easy to distinguish.

Practical Project Checklist

Further Technical Reading

• Eurocircuits: BOM & CPL data