| abstract |
A multi-piece wiring substrate includes a matrix substrate including a first main surface, a second main surface opposite to the first main surface, a third main surface disposed between the first main surface and the second main surface, an arrangement of a plurality of wiring substrate regions, a margin region surrounding the plurality of wiring substrate regions, and a dividing groove. The multi-piece wiring substrate further includes a through-hole disposed across the boundary between the wiring substrate regions or the boundary between the wiring substrate regions and the margin region, and which penetrates from the first main surface to the second main surface, and an external connection conductor at each corner of the wiring substrate regions on the second main surface. An auxiliary conductor is disposed around the through-hole on the third main surface. |