A wiring board includes an insulating substrate, at least one external electrode disposed on a first surface of the insulating substrate, and wiring that is disposed in the insulating substrate and that is electrically connected to the at least one external electrode. The wiring includes a portion where an extension direction of the wiring is inclined relative to the first surface of the insulating substrate.

A printed circuit board includes a first chip component, a second chip component, and a printed wiring board. The first chip component and the second chip component each has a length L2 in the longitudinal direction. A relationship of 0.894≤L2/L1≤1.120 is satisfied, where L1 represents a length of the first opening in the longitudinal direction. A relationship of 0.894≤L2/L4≤1.120 is satisfied, where length L4 represents a length of the second opening in the longitudinal direction. A relationship of 0.183≤L.sub.OA/L.sub.iA≤0.309 is satisfied, where L.sub.iA represents a length of the first land in the longitudinal direction, and L.sub.OA represents a thickness of solder on an end surface of the first electrode. A relationship of 0.183≤L.sub.OB/L.sub.iB≤0.309 is satisfied, where L.sub.iB represents a length of the second land in the longitudinal direction, and L.sub.OB represents a thickness of solder on an end surface of the second electrode.

A circuit board being able to easily ensure flatness of solder placed on a substrate for bonding an electronic component and improve bonding reliability of the electronic component by the solder, includes: a substrate having a plurality of layers made of a conductive material; a land provided on a first layer arranged on one side of the substrate, to which the electronic component is soldered; a heat sink provided on a different layer arranged on the substrate; a via hole provided on the substrate from a part of the land over to a part of the heat sink and electrically connected to the land and the heat sink; and an insulating resist disposed on the land and surrounding the entire circumference of the via hole.

A printed circuit board includes an insulating layer, a circuit pattern embedded in the insulating layer and including a first metal layer, a second metal layer and a third metal layer disposed between the first metal layer and the second metal layer, and a connection conductor disposed on one surface of the insulating layer and connected to the circuit pattern, wherein the first metal layer is exposed through the one surface of the insulating layer.

Methods for forming circuit boards and circuit boards using an adhesion layer are described. A substrate with two surfaces is exposed to a bifunctional organic compound to form an adhesion layer on the first substrate surface. A resin layer is then deposited on the adhesion layer and the exposed substrate surfaces. Portions of the resin layer may be removed to expose metal pads for contacts.

A printed circuit board includes an insulating layer, a circuit pattern on the insulating layer, and a surface treatment layer on the circuit pattern. The surface treatment layer includes a bottom surface having a width wider than a width of a top surface of the circuit pattern.

A resin substrate includes a resin base material including a first main surface, electrode pads provided on the first main surface, circuit conductor patterns, a resist film, and a coverlay film. The resist film includes, on the outer circumference, a plurality of protruding portions each of which has a tapered shape with a vertex. A portion of the circuit conductor patterns are covered with the resist film, and the coverlay film covers a portion of the resist film including the protruding portions and exposed portions of the circuit conductor patterns. The protruding portions are located at positions sandwiching the exposed portions of the circuit conductor patterns.

A device and substrate are disclosed. An illustrative device includes a substrate having a first surface and an opposing second surface, a solder material receiving curved surface exposed at the second surface of the substrate, a solder resist material that at least partially covers the solder material receiving curved surface such that a middle portion of the solder receiving curved surface is exposed and such that an edge portion of the solder material receiving curved surface is covered by the solder resist material and forms an undercut, and a solder material disposed within the solder material receiving curved surface and within the undercut.

A printed wiring board includes a base insulating layer, a conductor layer formed on the base layer and including first and second pads, a solder resist layer formed on the base layer such that the solder resist layer has first opening exposing the first pad and second opening exposing the second pad with diameter smaller than diameter of the first opening, and bumps including a first bump on the first pad and a second bump on the second pad such that the second bump has diameter smaller than diameter of the first bump. The first bump has a base plating layer formed in the first opening and having raised portion, and a top plating layer formed on the base plating layer, and the second bump has a base plating layer formed in the second opening and having raised portion, and a top plating layer formed on the base plating layer.

Methods for forming circuit boards and circuit boards using an adhesion layer are described. A substrate with two surfaces is exposed to a bifunctional organic compound to form an adhesion layer on the first substrate surface. A resin layer is then deposited on the adhesion layer and the exposed substrate surfaces. Portions of the resin layer may be removed to expose metal pads for contacts.