Wiring substrate and method of manufacturing the same
A wiring substrate includes an insulating layer, at least one via hole formed in the insulating layer, a first wiring layer formed on one surface of the insulating layer and having a droop portion at an end-side of the via hole, a second wiring layer formed on the other surface of the insulating layer, and a metal-plated layer formed in the via hole and configured to connect the second wiring layer and the droop portion of the first wiring layer. One surface of the insulating layer around the via hole is formed as a convex curved surface and the droop portion of the first wiring layer is arranged on the convex curved surface.
1. A wiring substrate comprising:
an insulating layer;
at least one via hole formed in the insulating layer;
a first wiring layer formed on one surface of the insulating layer and having a droop portion at an end-side of the via hole;
a second wiring layer formed on the other surface of the insulating layer; and
a metal-plated layer formed in the via hole and configured to connect the second wiring layer and the droop portion of the first wiring layer,
wherein one surface of the insulating layer around the via hole is formed as a convex curved surface and the droop portion of the first wiring layer is arranged on the convex curved surface.
2. The wiring substrate according to claim 1 , wherein the droop portion of the first wiring layer is configured to cover a side surface of the via hole.
3. The wiring substrate according to claim 2 , wherein a length of the droop portion of the first wiring layer is different in at least two positions of the via hole.
4. The wiring substrate according to claim 2 , wherein a plurality of the via holes are formed in the insulating layer, and lengths of the droop portions of the first wiring layer are different between the plurality of the via holes.