Choose surface finish for pad planarity, solderability, assembly process and storage requirements. A preferred finish still needs a compatible land and inspection plan.
What to consider
Fine-pitch components often benefit from a controlled, planar surface. Compare the chosen finish with the assembler’s process and any wire-bonding or contact requirements. Avoid treating a finish name as evidence of a guaranteed shelf life; packaging, handling and the supplier’s conditions matter.
A practical review example
If a board combines fine-pitch BGA lands and edge contacts, separate the requirements for soldered pads and contact surfaces. One blanket finish note may not communicate both needs.
Checks before release
- Specify finish and any special contact areas.
- Confirm compatibility with assembly and rework.
- Agree packaging and handling requirements.
Connect this decision to fabrication
Use the lamination guide to organize the initial discussion. Keep proposed values separate from the approved drawing and document the effect of any change on the rest of the construction.
- Ask the fabricator to confirm the complete construction in writing.
- Resolve manufacturing exceptions before tooling.
- Retain the approved drawing, stackup and inspection plan with the release.
Technical references
Fabrication design guidelinesConstruction-specific HDI capabilities and FAQReferences checked 2 October 2026. Manufacturer data describes its stated construction and is not an HDIPCB.org manufacturing commitment.