PCB Assembly
BOM and placement-file checklist
Review BOM and placement data together. Download clearly marked CSV examples to see the information to provide.
BOM checklist
| Field | Meaning |
|---|---|
| Reference | Component designator, such as R1 or U1; identify DNP positions. |
| Quantity per board | Count per assembled board, distinct from the production batch quantity. |
| Manufacturer and part number | Use complete, real orderable manufacturer identifiers for your production BOM. |
| Description / value / package | Information used to distinguish similar-looking parts. |
| Substitution instruction | State whether an alternative is allowed and what must be confirmed. |
Placement checklist
| Field | Meaning |
|---|---|
| Reference | Must match the BOM and drawing. |
| X / Y | State units and the shared coordinate origin. |
| Rotation | State the export convention; confirm orientation against the assembly drawing. |
| Side | Identify top or bottom explicitly. |
Download format examples
Illustrative format only — not production data. The files contain placeholder part numbers and arbitrary coordinates. Replace them with verified exports from your actual design. Acceptance and any required conversion are confirmed during project review.
Common issues to resolve
- A populated designator appears in only one file.
- Batch quantity is used instead of quantity per board.
- Placement units or origin are missing.
- A part number is truncated or a proposed substitute has not been approved.
- The export rotation does not match the drawing for a polarized part.
Before sending the files
Match all files to one revision and include the complete assembly package. Request assembly review.
Still need help?
Email service@esp32s.com with your order or request reference and the details of your question.