Bare-board fabrication produces the interconnection structure before components are assembled. Review the manufacturing data, construction requirements and board-level acceptance evidence as separate parts of the order.
What the fabrication order includes
A bare PCB contains the conductive features and supporting construction specified in its released data. It does not yet contain the complete assembled circuit. Its acceptance therefore concerns the board requirements, not the functional behavior of a product that has not been assembled.
Define the layer count, finished thickness, material, copper requirements, surface finish and mechanical features. Link these notes to the same revision as the fabrication files. If the drawing and order form disagree, resolve the difference before production begins.
Review the released data
- Check that all intended copper layers are present and identified.
- Overlay the profile and drilling data with the copper to check alignment.
- Identify plated and non-plated holes and any routed or slotted features.
- Confirm solder mask and legend layers correspond to the released board sides.
- Include the stackup, tolerances and special construction requirements.
A drill map is a useful review aid but is not the same as machine-readable drill data. Likewise, a screenshot of a board is useful context but does not replace the controlled manufacturing package. Ask the fabricator to state which supplied files are being used for production.
Understand the process without assuming one universal route
Fabrication normally involves preparing and patterning conductors, forming the board construction, producing interlayer connections where required, applying protective and solderable surfaces, and completing the profile. The exact sequence depends on the board technology. A single-sided board and a sequentially built HDI board should not be described as if every manufacturing operation were identical.
For project planning, focus on the operations that create a requirement or inspection need. A special via structure, controlled-depth feature or mixed-material stackup should have a clear drawing callout and an agreed verification method.
Distinguish electrical board test from product function
| Evidence | What it can establish |
|---|---|
| Dimensional inspection | The measured features meet the defined drawing requirements. |
| Connectivity testing | The tested conductive networks satisfy the specified continuity and isolation checks. |
| Controlled-impedance measurement | The agreed structures meet the defined impedance criteria under the agreed test. |
| Assembled functional testing | The populated product meets a defined operating test; this is a separate stage. |
A connectivity test does not prove that the schematic is correct or that the finished electronic product will work. Agree on the reference data used for the test and request the reports that the order actually requires. Treat unexplained test exclusions as open issues.
Close the order with traceable records
Keep fabrication questions, approved deviations and final construction details with the board revision. At receipt, check the identification, quantity and required documentation before assembly. Report discrepancies with photographs or measurements that identify the affected board and requirement.
If a repeat order changes material, tooling or approved construction, determine whether any prior evidence remains applicable. Use the fabrication overview and DFM checklist when preparing a new release.
Move from reading to a build-ready project
Use the fabrication and assembly checklists to prepare drawings, production files and test requirements.
Open the DFM checklist