Stacked microvias share a vertical location; staggered microvias offset successive transitions. The decision trades lateral routing area against construction and interface demands.
What to consider
Staggering can reduce a continuous vertical stack but requires space for offset lands and connecting copper. Stacking can preserve breakout density yet relies on qualified filling, planarity and interfaces. Neither geometry is automatically reliable for every thermal environment. Request data for the actual combination of layers, materials and assembly exposures.
A practical review example
Compare the same two-level transition as a stacked pair and as an offset pair. Measure the routing area consumed by the offset, then compare process capability and validation evidence for each.
Checks before release
- Show offset dimensions or stacked alignment explicitly.
- Review interactions with a buried core via.
- Specify thermal testing representative of assembly and service.
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.