Abstract: A method for manufacturing a printed wiring board includes laminating a first insulative resin layer including low dielectric constant material on a first surface of a base substrate, forming a first conductive layer including a metal foil on the first insulative resin layer, laminating a second insulative resin layer including prepreg material on a second surface of the base substrate on the opposite side with respect to the first surface, and forming a second conductive layer including a metal foil on the second insulative resin layer. The first insulative resin layer is formed such that a dielectric constant of the first insulative resin layer is set lower than a dielectric constant of the second insulative resin layer.

Abstract: A printed wiring board includes a base substrate, a first insulative resin layer laminated on first surface of the base substrate, and a first conductive layer laminated on the first insulative resin layer. The base substrate includes conductive layers and insulative resin layers, the base substrate, first insulative resin layer and first conductive layer include a high-frequency substrate portion including portion of an outermost conductive layer in the base substrate, portion of the first insulative resin layer and portion of the first conductive layer, the first conductive layer has wiring patterns including microstrip lines and the portion forming the high-frequency substrate portion, the first insulative resin layer has dielectric constant of 3.5 or lower and dielectric loss tangent of 0.005 or lower, and the wiring pattern is formed such that side surfaces of the wiring pattern are substantially parallel to a thickness direction of the first insulative resin layer.