Give each view a clear purpose

Use a dimensioned outline for finished mechanical requirements, a stack view for layer construction and a via table for connectivity and treatment. Do not crowd all requirements into one cross section. A reviewer should be able to locate the rule governing a feature without interpreting decorative geometry.

Altium's documentation describes layer stack and drill tables as fabrication drawing elements. Generate these from the controlled design where practical, then review the exported drawing; automatic generation does not eliminate the possibility of stale or incomplete inputs.

State which dimensions are finished requirements

Distinguish finished board thickness, finished hole dimensions and any process information supplied for discussion. Mark critical datum relationships and tolerances. Avoid overconstraining noncritical geometry with values copied from another project, because each extra requirement can introduce an unnecessary manufacturing exception.

For HDI, show the actual layer numbers reached by every via type. Add notes for required fill, cap or other treatment with terminology agreed with the supplier. A generic symbol for a blind via is not enough to define a multilayer construction.

Make performance requirements reviewable

For controlled impedance, reference a table that identifies signal layer, reference layers, target, tolerance and associated structure. State how changes to artwork or construction are approved. Keep material alternatives and required properties explicit rather than hiding them in a general note.

  • Board identifier, drawing revision and matching data package.
  • Outline, slots, cutouts and critical mechanical datums.
  • Layer sequence, via span table and special treatments.
  • Acceptance documents, required reports and approval conditions.

Check for contradictions before release

Compare the drawing against the actual export in an independent viewer. Check layer count, hole totals, outline orientation and via spans. Confirm that the board revision in the title block matches the archive and purchase request.

Define how conflicts will be resolved instead of assuming an unwritten document hierarchy. If a drawing note and data file disagree, require an engineering disposition and corrected baseline. A supplier's question should lead to a traceable correction, not an undocumented verbal interpretation.

DESIGN NOTE / SCHEMATIC

Adjacent-layer access, one connection at a time

Signal copper

Dielectric · geometry + material

Reference copper

Core or build-up dielectric

Signal copper

Illustrative only. Copper thickness, dielectric construction and via spans require a reviewed stackup.

Common questions

Can a fabrication drawing replace drill and copper data?

No. It communicates requirements and context. Supply the agreed machine readable fabrication data as well, with consistent revisions and coordinates.

Should every drawing note come from a standard template?

Use templates as a starting point, then remove irrelevant notes and verify the remaining requirements. A copied specification can create obligations the design does not need or satisfy.

References & further reading

Method & assumptions · General design guidance. Validate the proposed construction and acceptance criteria for your project.