The distinction is where a via begins and ends. A blind via reaches inward from a surface, a buried via stays inside the finished board, and a through via crosses the board.
What to consider
Compare these options by required layer access, pad consumption, unused stub and fabrication sequence. Through vias are useful and often economical, but they occupy routing space across layers. Blind and buried interconnects can reclaim that space where the design benefits justify the added process.
A practical review example
Draw the same net using each feasible structure. Compare the total path, plane openings and occupied routing channels rather than comparing only the surface pad diameter.
Checks before release
- Identify the exact connected layers.
- Check unused stubs and reference transitions.
- Ask the fabricator to quote the complete alternative constructions.
Connect this decision to fabrication
Use the design checklist 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.
- Record depth and diameter using the same units and measurement convention.
- Check capture lands, target lands and registration together.
- Match the test coupon to the actual interconnect construction.
Technical references
Fabrication design guidelinesHistorical IPC microvia reliability warning (2019)References checked 2 October 2026. Manufacturer data describes its stated construction and is not an HDIPCB.org manufacturing commitment.