Patent ID: 7800917
Filing Date: 2010-09-21
Classification: H05K

Abstract:
1. A printed wiring board comprising: an insulative substrate; a first wiring layer formed on at least one surface of the substrate; an insulating layer having a dual-layer structure comprising (i) a first insulating layer formed on the first wiring layer, the first insulating layer being formed of a cured insulative sheet made of a high-stiffness sheet-type reinforcing material containing resin, and (ii) a second insulating layer formed on the first insulating layer, the second insulating layer having concave sections and being formed of an insulating resin ink; and a second wiring layer made of a conductive material and formed on the insulating layer; wherein the insulating layer having the dual-layer structure is provided between the first wiring layer and the second wiring layer; wherein the first and second wiring layers are electrically connected to each other through at least one hole having a bottom; and wherein the second wiring layer is united with the second insulating layer at an interface of the second insulating layer with the second wiring layer, such that the conductive material of the second wiring layer is injected into the concave sections provided in the second insulating layer at the interface.