PCB Silkscreen Checks: Keep Labels Useful After Assembly

Silkscreen should help someone assemble, connect or diagnose the real board. A legend that looks attractive in CAD can become unreadable after manufacturing or disappear under fitted components. Review it in the context of the finished assembly and the people who will use it.

Prioritize the information people need

Identify polarity marks, connector pin labels, board identification and revision information. Add reference designators where they support assembly or service. Keep required safety or compliance markings under the product's separate review process; a general silkscreen checklist does not establish their content or validity.

For a connector that may be accessed in the field, check whether the label is visible from the actual viewing direction. A correct pin label hidden beneath a plug offers little help. Consider using the assembly documentation where the board surface cannot accommodate clear text.

Review manufacturing conflicts

Eurocircuits' legend-print guidelines explain that silkscreen is applied over the board surface and may be clipped around exposed features. Consequently, text crossing a solderable pad should not be relied on to survive unchanged. Confirm the applicable text and clearance limits with the fabricator instead of copying another supplier's minimum values.

Display legend, solder mask and copper together. Look for characters broken by openings, marks too close to the board edge and labels that overlap each other. Then view the assembled-component outlines to find information that will be covered.

Check polarity against the actual part

A triangle, dot or plus sign is useful only when its meaning is clear and correct for the device. Compare the footprint marking with the exact package drawing and assembly view. Do not assume that every visible stripe or dot identifies the same electrical terminal across different component families.

• Confirm connector numbering and signal names against the schematic.
• Check top and bottom text orientation separately.
• Keep essential marks away from pads and cutouts.
• Verify that the printed board revision matches the release.
• Inspect the exported legend files, not only the editor view.

Validate at a realistic scale

Review a true-scale print or a measured viewer display and check the first manufactured sample. Ask a colleague to locate a connector and identify its orientation using only the available labels. If the task requires guessing, improve the legend or accompanying drawing before the next release. Preserve the reviewed markings when updating footprints or moving components.

Technical reference: Eurocircuits: legend-print considerations. Supplier-specific process limits in the reference are not DIYIPCB manufacturing commitments.