Multi-level circuit substrate, method for manufacturing same and method for adjusting a characteristic impedance therefor

Abstract

An insulator is provided between interconnect layers oppositely placed. The interconnect layers are connected between by connection members provided through the insulator. The connection members at one and the other ends are connected between in their center positions. A shield layer is provided spaced from the intermediate connection layer generally on a same plane as the intermediate connection layer. The interconnect layers where considered generally as a circular cylinder have a diameter m, and the intermediate connection layer where considered generally as circular has a diameter r, r<m is given where the connection members are high in characteristic impedance than the interconnect layers, and r<m is given where the connection members are low in characteristic impedance then the interconnect layers.