How to use this tool
Select a layer count and architecture. The drawing highlights adjacent-layer microvia access, while the explanation identifies the conventional core. The drawing deliberately omits dimensions: a useful stackup must also specify pressed dielectric thickness, copper, references, via spans and material constructions.
Interpret the result
Changing from 1+N+1 to any-layer changes where transitions can be placed. It does not, by itself, prove that a smaller board or fewer layers will route. Use the drawing to frame a discussion with your layout engineer and fabricator.
Method & assumptions · General design guidance. Validate the proposed construction and acceptance criteria for your project.