WIRING BOARD

1 . A wiring board comprising:

an insulating layer having lower-layer conductors on a lower surface of the insulating layer;

a semiconductor element mounting portion formed on the insulating layer;

a plurality of semiconductor element connection pads arranged in a lattice pattern on the semiconductor element mounting portion;

via holes formed in the insulating layer under the semiconductor element connection pads with the lower-layer conductors as bottom surfaces; and

via conductors formed integrally with the semiconductor element connection pads and formed in the via holes to be electrically connected to the lower-layer conductor, wherein

the semiconductor element connection pads include first semiconductor element connection pads formed at outer peripheral corner portions of the semiconductor element mounting portion and other second semiconductor element connection pads, and

diameters of the via conductors connected to the first semiconductor element connection pads are larger than diameters of via conductors connected to the second semiconductor element connection pads.

2 . The wiring board according to claim 1 , further comprising an insulating board formed on a lower surface side of the insulating layer.

3 . The wiring board according to claim 1 , wherein a solder resist layer having openings that expose the first and second semiconductor element connection pads is adhered to a surface of the insulating layer, and the diameters of the openings that expose the first semiconductor element connection pads are equal to or larger than the diameters of the openings that expose the second semiconductor element connection pads.

4 . A wiring board comprising:

an insulating layer having lower-layer conductors on a lower surface of the insulating layer;

a semiconductor element mounting portion formed on the insulating layer;

a plurality of semiconductor element connection pads arranged in a lattice pattern on the semiconductor element mounting portion;

via holes formed in the insulating layer under the semiconductor element connection pads with the lower-layer conductors as bottom surfaces; and

via conductors formed integrally with the semiconductor element connection pads and formed in the via holes to be electrically connected to the lower-layer conductor, wherein

the semiconductor element connection pads include first semiconductor element connection pads formed at outer peripheral corner portions of the semiconductor element mounting portion and other second semiconductor element connection pads, and

with respect to at least the first semiconductor element connection pads, a plurality of via conductors are formed for each of the first semiconductor element connection pads.

5 . The wiring board according to claim 4 , further comprising an insulating board formed on a lower surface side of the insulating layer.

6 . The wiring board according to claim 4 , wherein the plurality of via conductors are arranged to be aligned along a direction toward a center of the semiconductor element mounting portion.

7 . The wiring board according to claim 4 , wherein one via conductor is formed for each of the second semiconductor element connection pads, a solder resist layer having openings that expose the first and second semiconductor element connection pads is adhered to a surface of the insulating layer, and diameters of the openings that expose the first semiconductor element connection pads are equal to or larger than the diameters of the openings that expose the second semiconductor element connection pads.

8 . A wiring board comprising:

an insulating layer having lower-layer conductors on a lower surface of the insulating layer;

a first mounting portion formed on the insulating layer and on which a first semiconductor element having a first electrode pitch is mounted;

a second mounting portion formed on the insulating layer and on which a second semiconductor element having a second electrode pitch smaller than the first electrode pitch and having diagonal lines shorter than diagonal lines of the first semiconductor element is mounted;

first semiconductor element connection pads formed on the first mounting portion with the same pitch as the first electrode pitch;

second semiconductor element connection pads formed on the second mounting portion with the same pitch as the second electrode pitch;

first via holes formed in the insulating layer under the first semiconductor element connection pads;

second via holes formed in the insulating layer under the second semiconductor element connection pads;

first via conductors formed integrally with the first semiconductor element connection pads and formed in the first via holes to be electrically connected to the lower-layer conductor, and

second via conductors formed integrally with the second semiconductor element connection pads and formed in the second via holes to be electrically connected to the second lower-layer conductor, wherein

diameters of the first via conductors are larger than the diameters of the second via conductors.

9 . The wiring board according to claim 8 , further comprising an insulating board formed on a lower surface side of the insulating layer.

10 . The wiring board according to claim 8 , wherein diameters of the first via conductors formed on an outer peripheral portion of the first mounting portion are larger than diameters of the first via conductors formed on a central portion of the first mounting portion.

11 . The wiring board according to claim 8 , wherein a solder resist layer having openings that expose the first and second semiconductor element connection pads is adhered to a surface of the insulating layer, and diameters of the openings that expose the first semiconductor element connection pads are equal to or larger than diameters of the openings that expose the second semiconductor element connection pads.

12 . The wiring board according to claim 10 , wherein a solder resist layer having openings that expose the first and second semiconductor element connection pads is adhered to a surface of the insulating layer, and diameters of the openings that expose the first semiconductor element connection pads on the outer peripheral portion of the first mounting portion are equal to or larger than diameters of the openings that expose the first semiconductor element connection pads on the central portion of the first mounting portion and diameters of the openings that expose the second semiconductor element connection pads.

13 . A wiring board comprising:

an insulating board having first lower-layer conductors on a lower surface of the insulating board and second lower-layer conductors on an upper surface of the insulating board;

a first insulating layer laminated on the lower surface of the insulating board to cover the first lower-layer conductor;

a second insulating layer laminated on the upper surface of the insulating board to cover the second lower-layer conductor;

a first mounting portion formed on the first insulating layer and on which a first semiconductor element having a first electrode pitch is mounted;

a second mounting portion formed on the second insulating layer and on which a second semiconductor element having a second electrode pitch smaller than the first electrode pitch and having diagonal lines shorter than diagonal lines of the first semiconductor element is mounted;

first semiconductor element connection pads formed with the same pitch as the first electrode pitch on the first mounting portion;

second semiconductor element connection pads formed with the same pitch as the second electrode pitch on the second mounting portion;

first via holes formed in the first insulating layer under the first semiconductor element connection pads;

second via holes formed in the second insulating layer under the second semiconductor element connection pads;

first via conductors formed integrally with the first semiconductor element connection pads and formed in the first via holes to be electrically connected to the first lower-layer conductor; and

second via conductors formed integrally with the second semiconductor element connection pads and formed in the second via holes to be electrically connected to the second lower-layer conductor, wherein

diameters of the first via conductors are larger than diameters of the second via conductors.

14 . The wiring board according to claim 13 , wherein diameters of the first via conductors formed on the outer peripheral portion of the first mounting portion are larger than diameters of the first via conductors formed on the central portion of the first mounting portion.

15 . The wiring board according to claim 13 , wherein a solder resist layer having openings that expose the first and second semiconductor element connection pads is adhered to surfaces of the first and second insulating layers, and diameters of the openings that expose the first semiconductor element connection pads are equal to or larger than diameters of the openings that expose the second semiconductor element connection pads.

16 . The wiring board according to claim 14 , wherein a solder resist layer having openings that expose the first and second semiconductor element connection pads is adhered to surfaces of the first and second insulating layers, and diameters of the openings that expose the first semiconductor element connection pads on the outer peripheral portion of the first mounting portion are equal to or larger than diameters of the openings that expose the first semiconductor element connection pads on the central portion of the first mounting portion and diameters of the openings that expose the second semiconductor element connection pads.