Note that, as shown in FIG. 6, each of the via wirings 46 is formed by depositing a metal film along a wall surface of a via hole 47 formed so as to penetrate the core insulating layer 41 from one of the surface 41A and the surface 41B to the other of the surface 41A and the surface 41B. Therefore, a through hole (portion of the via hole 47) remains in a center of the via wiring 46 formed in the via hole 47. For example, in a case where a solder material is used as the conductive joint material SB and the amount of the applied solder material is large, the solder material can creep up to the terminal 45 on the surface 41B side via the through hole which is a portion of the via hole 47. Each of the terminals 45 is not covered by the solder resist film SR1. Therefore, in a case where the solder material creeps up to the surface 41B side (that is, the connection region 40C2 side) and the separation distance between the terminals 45 is short, short-circuiting can occur in adjacent terminals 45 via the solder material.

In the case of the present embodiment, the separation distance (such as the separation distance 45GP1) between each of the terminals 45 is larger than the separation distance 44GP1 between the signal terminal 44s1 and the reference potential terminal 44g1. Therefore, even in a case where the conductive joint material SB which is a solder material goes around to the connection region 40C2 side, short-circuiting in the signal terminal 44s1 and the reference potential terminal 44g1 via the solder material can be prevented.