Patent ID: 8330054

Claim:
A printed circuit board on which a circuit element is mounted and to which an external circuit is connected, comprising: a first insulating layer having a mounting region, in which the circuit element is mounted, on one surface; a plurality of first connection terminals that are formed in a region, which excludes said mounting region, on said one surface of said first insulating layer and that can be connected to said external circuit; a plurality of second connection terminals that are formed in said mounting region on said one surface of said first insulating layer and that can be connected to a plurality of terminals of said circuit element, respectively; a plurality of conductor lines that are formed to extend between said plurality of first connection terminals and said plurality of second connection terminals on said one surface of said first insulating layer; and a conductive layer that is formed in a region on the other surface of said first insulating layer that is opposite to a region on said one surface of said first insulating layer including said plurality of conductor lines, wherein adjacent conductor lines constitute a transmission line pair, a width of each conductor line is set to not more than 250 μm, a distance between the adjacent conductor lines is set to not less than 8 μm, and differential impedance of the transmission line pair is not less than 10 Ω and not more than 50 Ω.