Wiring board
A wiring board includes a core substrate having a number of through-holes, and buildup insulating layers and buildup wiring layers alternately laminated on upper and lower surfaces of the core substrate, in which a first through-hole group is arranged in a first region in the core board at a first arrangement density, the first region being opposed to the semiconductor element connection pad formation region, a second through-hole group is arranged in a second region at a second arrangement density lower than the first arrangement density, the second region being located in an outer peripheral portion of the core substrate and away from the first region, and a third through-hole group is arranged in a third region at a third arrangement density higher than the second arrangement density, the third region being located between the first region and the second region.
1. A wiring board comprising:
a core substrate having a number of through-holes; and
buildup insulating layers and buildup wiring layers alternately laminated on upper and lower surfaces of the core substrate, the wiring board having a semiconductor element connection pad formation region where a number of semiconductor element connection pads made of the buildup wiring layer are arranged in a lattice-like form in a center of an upper surface, wherein
a first through-hole group is arranged in a first region in the core substrate at a first arrangement density, the first region being opposed to the semiconductor element connection pad formation region,
a second through-hole group is arranged in a second region at a second arrangement density lower than the first arrangement density, the second region being located in an outer peripheral portion of the core substrate and away from the first region, and
a third through-hole group is arranged in a third region at a third arrangement density higher than the second arrangement density, the third region being located between the first region and the second region.
2. The wiring board according to claim 1 , wherein
external connection pads made of the buildup wiring layer are arranged in a center of a lower surface.
3. The wiring board according to claim 1 , wherein
the third arrangement density is equal to or smaller than the first arrangement density.
4. The wiring board according to claim 1 , wherein
the first through-hole group includes a grounding through-hole and a power supply through-hole.
5. The wiring board according to claim 1 , wherein
the second through-hole group includes a signal through-hole.
6. The wiring board according to claim 1 , wherein
the third through-hole group includes a dummy through-hole.