Printing wiring board, core substrate, and method for fabricating the core substrate

A printed wiring board comprising a core substrate having front and back surfaces, at least one insulating resin layer laminated onto the front and back surfaces of the core substrate, and a wiring layer formed at least between the core substrate and the insulating resin layer or between the insulating resin layers, the core substrate comprising:

• a center substrate having front and back surfaces;
• first and second laminated capacitors formed, respectively, on the front and back surfaces of the center substrate, each laminated capacitor comprising at least one composite dielectric layer containing resin and a high-permittivity powder, and a plurality of metal layers stacked alternately with the composite dielectric layers so as to sandwich the composite dielectric layers therebetween;
• and
• a plurality of through-hole conductors each formed in a through-hole extending through the first laminated capacitor, the center substrate, and the second laminated capacitor, the through-holes conductors extending between the front and back surfaces of the core substrate and including first, second and third through-hole conductors, the first through-hole conductors being directly connected to at least one metal layer of the plurality of metal layers of the first laminated capacitor and serving as a first electrode of the first laminated capacitor, and to at least one layer of the plurality of metal layers of the second laminated capacitor and serving as a first electrode of the second laminated capacitor, the second through-hole conductor being directly connected to at least one metal layer of the plurality of metal layers of the first side laminated capacitor and serving as a second electrode of the first laminated capacitor, and to at least one metal layer of the plurality of metal layers of the second laminated capacitor and serving as a second electrode of the second laminate capacitor, and the third through-hole conductor being unconnected to any of the electrodes of the first and second laminated capacitors.

A core substrate which is used to fabricate a printed wiring board through lamination of at least one insulating resin layer and wiring layer on each of front and back surfaces of the core substrate, the core substrate comprising:

• a plurality of composite dielectric layers each containing resin and a high-permittivity powder and including an uppermost composite layer and a lowermost composite layer;
• a plurality of metal layers stacked alternately with the composite dielectric layers such that the metal layers are disposed between the composite dielectric layers, as well as on a lower surface of the lowermost composite dielectric layer, and on an upper surface of the uppermost composite dielectric layer, so as to sandwich the composite dielectric layers between the metal layers to thereby form a laminated capacitor;
• and
• a plurality of through-holes conductors each of which is formed in a through-hole penetrating the plurality of composite dielectric layers and the plurality of metal layers and each of which extends between the front and back surfaces of the core substrate, the through-hole conductors including a first through-hole conductor directly connected to first interior metal layers which comprise alternate interior metal layers formed between the composite dielectric layers;
• a second through-hole conductor directly connected to second interior metal layers which comprise second alternate interior metal layers and which are not connected to the first through-hole conductors;
• and a third through-hole conductor unconnected to any of the interior metal layers.

A core substrate for use in fabricating a printed wiring board through lamination of at least one insulating resin layer and wiring layer on each of front and back surfaces of the core substrate, the core substrate comprising:

• a center substrate having front and back surfaces;
• first and second capacitor formed, respectively, on the front and back surfaces of the center substrate, each laminated capacitor comprising at least one composite dielectric layer containing resin and a high-permittivity powder, and a plurality of metal layers stacked alternately with the composite dielectric layers so as to sandwich the composite dielectric layers therebetween;
• and
• a plurality of through-hole conductors each formed in a through-hole extending through the first laminated capacitor, the center substrate, and the second laminated capacitor, the through-hole conductors extending between the front and back surfaces of the core substrate and including first, second and third through-hole conductors, the first through-hole conductor being directly connected to at least one metal layer of the plurality of metal layers of the first laminated capacitor and serving as a first electrode of the first laminated capacitor, as well as to at least one metal layer of the plurality of metal layers of the second laminated capacitor and serving as a first electrode of the second laminated capacitor, the second through-hole conductor being directly connected to at least one metal layer of the plurality of metal layers of the first laminated capacitor and serving as a second electrode of the first laminated capacitor, as well as to at least one metal layer of the plurality of metal layers of the second laminated capacitor and serving as a second electrode of the second laminated capacitor, and the third through-hole conductor being unconnected to any of the electrodes of the first and second laminated capacitors.