Patent ID: 8458900

Claim:
A method of making a wiring substrate having at least one interconnection layer, comprising: a first metal layer forming step of forming a first metal layer on a surface of a support member, the first metal layer having at least one colmmnar through hole that exposes part of the surface of the support member; a columnar metal layer forming step of forming a columnar metal layer that fills the columnar through hole; an insulating layer forming step of forming an insulating layer on the columnar metal layer and on the first metal layer; an interconnection layer forming step of forming an interconnection layer on a first surface of the insulating layer such that the interconnection layer is electrically connected to the columnar metal layer through the insulating layer; and a protruding part forming step of forming, by removing at least an entirety of the support member and an entirety of the first metal layer, a protruding part including at least part of the columnar metal layer protruding from a second surface of the insulating layer opposite the first surface, the protruding part serving as at least part of a connection terminal of the wiring substrate.