Laser drilling creates small interconnect openings in selected dielectric layers. Material, copper treatment, depth control and subsequent cleaning all affect the result.
What to consider
A nominal hole diameter does not describe taper, bottom contact or the condition of the exposed target. The fabrication process must remove residue and prepare a reliable conductive interface. Ask whether the proposed laminate and dielectric thickness are within the qualified drilling and metallization window.
A practical review example
Compare the drawing’s nominal diameter with the factory’s top and bottom diameter conventions. Confirm that the target land and dielectric depth remain compatible after any stackup adjustment.
Checks before release
- Confirm hole measurement conventions.
- Identify the actual target layer.
- Review drilling, desmear and plating as one process.
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.