Patent ID: 8813353

Claim:
A method for manufacturing a dielectric structure in which the dielectric structure includes a metal foil, a dielectric layer and a conductor layer provided in this order, vias which penetrate through both of the dielectric layer and the conductor layer, and through-holes which penetrate through the metal foil so as to communicate with the respective vias, the method comprising: forming the dielectric layer on the metal foil; forming the conductor layer on a side of the dielectric layer opposite the metal foil; and simultaneously forming the respective vias by laser light through both of the conductor layer and the dielectric layer after the conductor layer is formed on the dielectric layer, wherein the vias of the dielectric layer have different diameters which are in a range of from 100 to 300 μm, a diameter of the respective vias of the conductor layer is larger than a diameter of a corresponding via of the dielectric layer by 5 to 50 μm, and a minimum via pitch is from 100 to 350 μm.