Patent ID: 9420708
Filing Date: 2016-08-16
CPC Classification: H01L,H05K,Y10T

Claim Text:
1. A method for manufacturing a printed wiring board, comprising: preparing a core substrate comprising a metal layer having a first penetrating hole and a plurality of insulation layers formed on the metal layer such that the metal layer is interposed between the insulation layers; forming in the core substrate a second penetrating hole having a first opening portion aligned with the first penetrating hole on a first-surface side of the core substrate and a second opening portion aligned with the first penetrating hole on a second-surface side of the core substrate; forming a first conductor on a first surface of the core substrate; forming a second conductor on a second surface of the core substrate on an opposite side of the first surface of the core substrate; and filling a conductive material in the second penetrating hole such that a through-hole conductor connecting the first conductor and the second conductor is formed, wherein the first penetrating hole of the metal layer has an inner wall such that the first penetrating hole has a diameter which becomes greater toward a center portion of the metal layer in a thickness direction of the metal layer, the forming of the second penetrating hole comprises setting a straight line passing through a gravity center of the first opening portion and perpendicular to the first surface or second surface of the core substrate off a straight line passing through a gravity center of the second opening portion and perpendicular to the first surface or second surface of the core substrate such that the straight line with respect to passing through the gravity center of the first opening portion is not aligned with the straight line passing through the gravity center of the second opening portion, and the forming of the second penetrating hole comprises forming a juncture portion of the first opening portion and the second opening portion shifted to one of the first-surface side and the second-surface side from a center portion of the metal layer in a thickness direction of the metal layer.