A wiring board, comprising:
- an insulating substrate in which a plurality of build-up insulating layers comprising a plurality of via holes is stacked on upper and lower surfaces of a core insulating layer comprising a plurality of through holes, the insulating substrate comprising a semiconductor-element mount portion at a center portion of an upper surface of the insulating substrate, a constant-voltage-regulator mount portion at an outer peripheral portion of the upper surface of the insulating substrate, and an external connection surface at a lower surface of the insulating substrate;
- and
- a wiring conductor applied on the upper and lower surfaces of the core insulating layer, in the through holes, on surfaces of the build-up insulating layers, and in the via holes,
- wherein the wiring conductor comprises
- a plurality of semiconductor-element connection pads for signal, for grounding, and for power supply in the semiconductor-element mount portion,
- a plurality of constant-voltage-regulator connection pads for grounding and for power supply in the constant-voltage-regulator mount portion,
- a plurality of external connection pads for signal, for grounding, and for power supply in the external connection surface,
- a plurality of wiring conductors for signal connected to the semiconductor-element connection pad for signal in an area below the semiconductor-element mount portion, connected to the external connection pad for signal in an outer peripheral portion of the insulating substrate, and extending in the insulating substrate from the area below the semiconductor-element mount portion to the outer peripheral portion of the insulating substrate,
- a plurality of solid conductors for grounding connected to the semiconductor-element connection pad for grounding in the area below the semiconductor-element mount portion, connected to the constant-voltage-regulator connection pad for grounding in an area below the constant-voltage-regulator mount portion, connected to the external connection pad for grounding in the area below the semiconductor-element mount portion and the area below the constant-voltage-regulator mount portion, and extending on surfaces of a plurality of the build-up insulating layers at an upper-surface side and a lower-surface side of the core insulating layer from the area below the semiconductor-element mount portion to the area below the constant-voltage-regulator mount portion, and
- a plurality of solid conductors for power supply connected to the semiconductor-element connection pad for power supply in the area below the semiconductor-element mount portion, connected to the constant-voltage-regulator connection pad for power supply in the area below the constant-voltage-regulator mount portion, connected to the external connection pad for power supply in the area below the semiconductor-element mount portion and the area below the constant-voltage-regulator mount portion, and extending on surfaces of a plurality of the build-up insulating layers at the upper-surface side and the lower-surface side of the core insulating layer from the area below the semiconductor-element mount portion to the area below the constant-voltage-regulator mount portion, and
- wherein the wiring conductors for signal extend on the surface of the build-up insulating layer, on which the solid conductor for grounding or the solid conductor for power supply extends, to the outer peripheral portion of the insulating substrate without passing through an area below an intermediate portion between the semiconductor-element mount portion and the constant-voltage-regulator mount portion.