Plan the path from build-up to core. Evaluate 2+10+2 or 3+8+3 as candidate notation, then verify the actual escape and plane allocation.
What to consider
A fourteen-layer board can have substantial routing space that is inaccessible from a dense package unless its core transitions are planned. Draw complete connections through the structure before routing.
Conceptual layer allocation
Compare 2+10+2 or 3+8+3. This illustration assigns copper functions only; it does not define dielectric thickness, impedance or an approved via structure.
| Build-up per side | Core copper layers | Total copper layers |
|---|---|---|
| 1 | 12 | 14 |
| 2 | 10 | 14 |
| 3 | 8 | 14 |
A practical review example
The supplied fourteen-layer examples illustrate possible structures, not universal recipes. A project using two build-ups must confirm how nets reach the middle core layers and which via structures need filling.
Checks before release
- Allocate signal, ground and power copper before counting routing capacity.
- Agree pressed dielectric values and finished thickness.
- Define every laser and mechanical via span.
Connect this decision to fabrication
Use the stackup planner 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.
- Give every signal layer a defined return-path strategy.
- Review material and copper balance about the board center.
- Specify every via span and the factory-approved lamination sequence.
Technical references
HDI construction types and definitionsFabrication design guidelinesReferences checked 2 October 2026. Manufacturer data describes its stated construction and is not an HDIPCB.org manufacturing commitment.