Patent ID: 8476537

Claim:
A multi-layer substrate comprising a planar transmission line and a signal via, wherein said planar transmission line and said signal via are connected by a multi-tier transition comprising: a signal via pad used for a full-value connection of said signal via and said planar transmission line; an another signal via pad connected to said signal via and disposed at a conductor layer which is nearest to said signal via pad between a signal terminal of said signal via and said signal via pad; and a dummy pad connected to said another signal via pad, formed in an area of a clearance hole at said conductor layer and isolated from said conductor layer, wherein said dummy pad comprises a form covering an area around a strip segment of said planar transmission line disposed in said area of said clearance hole and providing a coupling to said strip segment connecting said signal via pad and said planar transmission line and said form does not comprise a conductive part in a side of said clearance hole which is opposite to said strip segment.