Patent ID: 8119925
Filing Date: 2012-02-21
Classification: H05K,Y10T

Abstract:
1. A core substrate comprising: a core layer including an electrically-conductive layer made of carbon fibers impregnated with resin and core insulating layers overlaid on front and back surfaces of the electrically-conductive layer, the core insulating layers made of glass fibers impregnated with resin; a through hole formed in the core layer, the through hole penetrating through the core layer from a front surface of the core layer to a back surface of the core layer; a cylindrical filling material filling the through hole; a pair of overlying insulating layers made of glass fibers impregnated with resin, the overlying insulating layers being overlaid on the front and back surfaces of the core layer, respectively, so that the core layer and the cylindrical filling material are sandwiched between the overlying insulating layers; a through bore formed in and penetrating through at least one of the overlying insulating layers along a longitudinal axis of the through hole; and an electrically-conductive via formed in a shape of a cylinder along an inward wall surface of the through bore.