Patent ID: 8826526

Claim:
A method of manufacturing a multilayer wiring substrate, the method comprising: an insulation layer fixation step of laying a lower metal foil and an upper metal foil directly on each other, disposing the lower metal foil, which is larger in outer shape than the upper metal foil, and the upper metal foil on a support base material, adhering a resin insulation material to a surface of the upper metal foil and an upper surface of a peripheral edge portion of the lower metal foil, and fixing a peripheral edge portion of the resin insulation material directly to the support base material; a lamination step of alternately laminating conductor layers and resin insulation layers on the resin insulation material so as to obtain a laminate structure having, on the upper metal foil, a wiring laminate portion which is to become the multilayer wiring substrate; a removal step of cutting, after the lamination step, the laminate structure along a boundary between the wiring laminate portion and a surrounding portion located around the wiring laminate portion, to thereby remove the surrounding portion; and a separation step of separating the wiring laminate portion from the support base material along a boundary between the upper and lower metal foils.