CIRCUIT BOAD INCLUDING A PLURALITY OF VIA STRUCTURES

摘要

A circuit board having plural via structures is provided to reduce the whole area of a via hole in the circuit board by connecting plural wiring positioned on upper and lower portions of the board by using a plurality of via. A circuit board includes a dielectric substrate having via structures(730,740), and a pair of signal wiring(721,723,724,726) formed on the dielectric substrate and connected to the via structure. The via structure has via-holes(731,741) penetrating through the dielectric substrate and a pair of via formed on an inner wall of the via hole and connected to the pair of wiring. The via-hole has plural sub via-holes which are formed to overlap one another.