What Release for Manufacturing Means for a PCB

A release is a decision attached to exact files

“The board is done” describes a feeling. “Revision C is released for manufacturing” means an authorized person approved a specific, reproducible set of source files and outputs after defined checks. Manufacturing can build that set without asking which Git commit, BOM spreadsheet, or Gerber ZIP is current.

The release boundary matters because EDA source changes constantly. If fabrication files are exported, then the PCB is edited and saved, the ZIP no longer represents the visible design. A release records both the approved source revision and hashes of the generated artifacts.

Do not use a working directory named final-final-2. Use immutable revision identifiers such as controller-pcb-r03, linked to a Git commit and an engineering change record.

Freeze the product configuration

Before running checks, write down what is being built:

• PCB assembly number and revision;
• schematic and PCB source commit;
• fitted variant and quantity;
• layer stackup, finished thickness, copper weight, and surface finish;
• controlled-impedance requirements;
• approved substitutions and do-not-fit parts;
• firmware or test image needed by assembly;
• intended fabricator/assembler capability profile.

Variants deserve special attention. The Gerbers may be common while BOM and placement files differ. Name every output with the variant and revision, and make sure DNP handling is consistent between BOM, position file, assembly drawing, and EDA attributes.

Complete the design evidence

A reasonable release gate requires:

1. Schematic peer review and resolved ERC.
2. PCB updated from schematic, DRC complete, and parity checked.
3. Datasheet review of critical footprints, connector orientation, polarity, and exposed pads.
4. Power, current, thermal, signal-integrity, and RF calculations appropriate to the board.
5. Mechanical review against enclosure, mounting, cable, and keepout constraints.
6. BOM validation using exact manufacturer part numbers and orderable package variants.
7. DFM review against the chosen manufacturing process.

An exclusion is not automatically a failure, but it must have an owner and technical reason. Record unresolved warnings and approved deviations instead of relying on a reviewer to remember them. The manufacturing gate article explains why this evidence is more reliable than the method used to create the design.

Run the pre-order PCB DFM checklist against the actual supplier’s limits, not generic “industry standard” values.

Generate a complete handoff package

For a typical assembled KiCad board, the package contains:

fab/
  copper and solder-mask Gerbers for every used layer
  top and bottom silkscreen Gerbers
  board outline/profile Gerber
  plated and non-plated Excellon drill files
  fabrication drawing and fabrication notes
assembly/
  BOM with reference, quantity, value, footprint, manufacturer, MPN, DNP
  top/bottom position or CPL files
  assembly drawing(s)
  stencil/paste outputs when requested
docs/
  readme with revision, units, origin, stackup, variants
  test/programming instructions
  release manifest and check reports

The BOM must identify real components, not only 10k or USB-C. Follow setting up a KiCad BOM with real part numbers. Position files need a documented coordinate origin, units, rotation convention, and board side; see CPL/XYRS files explained.

Do not include stale output from a previous run. Generate into an empty revision directory and fail if the source tree is dirty or checks fail.

Inspect the outputs as manufacturing sees them

Passing DRC does not validate an export configuration. Load the Gerbers and drill files into an independent viewer. Check:

• all expected copper layers exist and align;
• board outline is one closed, correctly sized profile;
• plated and non-plated holes appear in the right locations;
• mask openings expose pads without unintended slivers;
• silkscreen is readable and clipped away from pads appropriately;
• bottom layers are not manually mirrored;
• panel instructions, slots, cutouts, and castellations are explicit;
• assembly references and polarity marks match the BOM and placement files.

Compare the fabrication viewer against a known mechanical dimension. Render top and bottom assembly views from the released outputs, not screenshots taken before export.

Write a machine-readable manifest

A small manifest makes the package auditable:

assembly: CTRL-1007
revision: R03
source_commit: 7d4c90e
kicad_version: 9.0.9
variant: standard
checks:
  erc: pass
  drc: pass
  schematic_parity: pass
approvals:
  engineering: initials/date
  manufacturing: initials/date
artifacts:
  - path: fab/CTRL-1007-R03-F_Cu.gtl
    sha256: "..."
  - path: assembly/CTRL-1007-R03-standard-bom.csv
    sha256: "..."

Include every delivered file or hash the final archive. Store the manifest beside the release in immutable storage. Hashes prove which bytes were approved; a filename alone does not.

Separate candidate generation from approval

Automation may generate a release candidate whenever checks pass. Approval should be a distinct action by someone authorized to accept cost and technical risk. A useful state model is:

working -> candidate -> reviewed -> released -> superseded

Only released artifacts go to procurement. If any source, BOM line, placement coordinate, drawing, or fabrication note changes, create a new candidate and rerun the affected checks. Do not patch a released ZIP in place.

When a fabricator proposes a change—larger drill, altered stackup, substituted laminate—capture the answer in the release record. If the change affects function or controlled geometry, revise the source and outputs rather than leaving the factory’s version as an undocumented fork.

Make the release useful after the order

The package should support incoming inspection, assembly, test, and a future respin. Record who approved it, supplier questions and answers, panelization ownership, first-article results, and known deviations. Link failures back to the exact serial/lot and release revision.

Release for manufacturing is therefore not synonymous with exporting Gerbers or clicking “order.” It is configuration control: exact source, complete outputs, recorded checks, explicit approval, and a change process that keeps every manufactured board traceable to the evidence used to approve it.