Wiring board, semiconductor device, and method for manufacturing wiring board
A wiring board includes a first insulating layer containing a thermosetting resin, a first wiring layer stacked on an upper surface of the first insulating layer, a second insulating layer stacked on the upper surface of the first insulating layer, a second wiring layer stacked on an upper surface of the second insulating layer, and a third insulating layer stacked on the upper surface of the second insulating layer. The second and third insulating layers contain a first photosensitive resin. An outer side surface of the second insulating layer is flush with an outer side surface of the first insulating layer. An outer side surface of the third insulating layer is located inside the outer side surface of the second insulating layer in a plan view. The upper surface of the second insulating layer connecting to the outer side surface thereof is exposed from the third insulating layer.
1. A wiring board, comprising:
a first insulating layer containing a thermosetting resin;
a first wiring layer stacked on an upper surface of the first insulating layer;
a second insulating layer stacked on the upper surface of the first insulating layer, the second insulating layer containing a first photosensitive resin;
a second wiring layer stacked on an upper surface of the second insulating layer, the second wiring layer electrically connecting to the first wiring layer; and
a third insulating layer stacked on the upper surface of the second insulating layer, the third insulating layer containing the first photosensitive resin, wherein
an outer side surface of the second insulating layer is flush with an outer side surface of the first insulating layer,
an outer side surface of the third insulating layer is located inside the outer side surface of the second insulating layer in a plan view, and
the upper surface of the second insulating layer connecting to the outer side surface of the second insulating layer is exposed from the third insulating layer.
2. The wiring board according to claim 1 , wherein
the first insulating layer further contains a filler,
the upper surface of the first insulating layer is formed with a recess portion, and
the second insulating layer fills the recess portion.
3. The wiring board according to claim 1 , further comprising:
a first wiring structure;
a second wiring structure stacked on an upper surface side of the first wiring structure; and
an outermost insulating layer stacked on a lower surface side of the first wiring structure, the outermost insulating layer containing a second photosensitive resin, wherein
the first wiring structure includes
the first insulating layer,
at least one third wiring layer provided under a lower surface side of the second insulating layer, the at least one third wiring layers electrically connecting to the first wiring layer,
at least one fourth insulating layer provided under a lower surface side of the first insulating layer, and
an outermost wiring layer provided on the at least one fourth insulating layer, the outermost wiring layer electrically connecting to the at least one third wiring layer,
the second wiring structure includes
the first wiring layer,
the second insulating layer,
the second wiring layer, and
the third insulating layer,
the outermost insulating layer exposes at least a part of the outermost wiring layer, and
a thickness of the outermost insulating layer is equal to or larger than a total sum of thicknesses of all insulating layers in the second wiring structure.
4. The wiring board according to claim 1 , wherein the second wiring structure is higher in wiring density than the first wiring structure.
5. The wiring board according to claim 1 , further comprising:
a through hole that opens on the upper surface of the first insulating layer and that penetrates through the first insulating layer in a thickness direction of the first insulating layer,
a via wiring that fills the through hole and that has an upper end surface exposed from the first insulating layer,
the upper end surface of the via wiring is flush with the upper surface of the first insulating layer, and
the first wiring layer connects to the upper end surface of the via wiring through a seed layer.
6. The wiring board according to claim 5 , wherein the upper surface of the first insulating layer is lower in surface roughness than an inner surface of the through hole.
7. The wiring board according to claim 1 , wherein the outer side surface of the third insulating layer is inclined.
8. The wiring board according to claim 1 , further comprising:
a through hole that opens on the upper surface of the first insulating layer and that penetrates through the first insulating layer in a thickness direction of the first insulating layer; and
a via wiring that fills the through hole and that has an upper end surface exposed from the first insulating layer, wherein
the upper surface of the first insulating layer and the upper end surface of the via wiring are polished surfaces.
9. The wiring board according to claim 1 , wherein the upper surface of the second insulating layer is smaller in surface roughness than the upper surface of the first insulating layer.
10. A semiconductor device, comprising:
the wiring board according to claim 3 ; and
a semiconductor chip that is flip-chip bonded to an outermost wiring layer of the second wiring structure.