US Patent 7193324 Circuit structure of package substrate

A circuit structure for a package substrate or a circuit board is provided. The circuit structure has a dielectric layer with an upper surface and a lower surface, at least a first line and at least a second line. The first line is disposed on the dielectric layer on which a base of the first line is aligned with the upper surface. In addition, the second line is disposed on the dielectric layer on which a base of the second line is embedded below the upper surface. Since the second line is embedded into the dielectric layer, the distance with a reference plane is reduced and the crosstalk between the signals is further effectively reduced.