The drilled span is not always the full boardThe actual processed span must be identified for each interconnect. Final board thickness is not automatically the correct depth for every aspect-ratio calculation.The drilled span is not always the full boardConceptual cross-section; thicknesses and proportions are illustrativeTop surface / capture featureBuild-up dielectricLanding conductorInternal subcompositeInternal conductorLower dielectric / surfaceDefine start and stop layers. Through, blind and buried features need different routes.³Ô¹Ïtv · Engineering explanation · Conceptual, not to scale