pcb-manufacturing-preflight

# PCB manufacturing preflight Run the repository's deterministic checks, then perform the checks that require engineering judgment in a CAM view. A passing script is necessary but is not by itself approval to manufacture. Boards with `external_footprints` in their profile also map package pads to physical copper nets using cached EasyEDA footprints selected by the JLCPCB BOM and placed by the JLCPCB PNP file. Normal preflight is cache-only. Refresh that independent source explicitly when a BOM selection changes: ```sh python3 tools/fetch_easyeda_footprints.py <board>-jlcpcb-bom.csv ``` The cache includes official EasyEDA symbol pin names. The report joins those names to the package pads and physical nets while retaining reference designator and pad number as provenance. ## Automated gate From the repository root, run: ```sh python3 tools/pcb_preflight.py <board-name> ``` This regenerates the board unless `--no-generate` is explicitly appropriate. Read the generated `<board-name>-preflight.html` report and resolve every failure. Use the selected board's profile in `preflight/`; do not generalize profile-only requirements to other boards. For example, `spiq_a` requires five GML contours because it has one perimeter and four routed USB-C mounting slots. The pinned part catalog distinguishes two BOM comment rules: - For resistors, capacitors, and other entries marked `discrete`, JLCPCB's `Comment` is the electrical value. It is not the manufacturer part number. - For entries marked `part`, `Comment` is the manufacturer part number. In both cases the LCSC number, emitted comment, emitted footprint, actual manufacturer part number, and manufacturer package are kept together in the catalog. Treat a change to any member of that selection as a part change that needs review. Current stock and Basic/Extended status are not guaranteed by the pinned catalog; verify them live when the user asks for current procurement status. ## Manual CAM gate Inspect the generated manufacturing files themselves, not only a PCB rendering: - Confirm the board outline, routed slots, plated lands, and drill hits exist in the submitted files and have the intended locations and sizes. - Compare mechanically critical and polarized footprints against their selected manufacturer datasheets, especially connectors and fine-pitch packages. - Inspect top and bottom copper for unintended crossings, shorts, via collisions, copper outside the substrate, and suspicious neck-downs or clearances. - Inspect solder mask, paste, and silkscreen alignment. Confirm paste is absent where intended and silkscreen does not obscure pads or leave the board edge. - Check edge clearances and slot clearances using the intended fabrication and assembly rules, including any V-score constraints. - Check PNP side, position, and rotation for representative asymmetric parts and confirm every populated BOM designator has exactly one placement. - Complete every board-specific manual item printed in the report. ## Result Report automated failures separately from manual findings. Say the board is ready only when both gates pass. Include the report path and identify any check that could not be completed; do not silently convert an unperformed check into a pass.