Abstract: A printed wiring board includes a first conductor layer, a resin insulating layer having an opening, a second conductor layer including a seed layer and an electrolytic plating layer formed on the seed layer, and a via conductor including the seed layer and the electrolytic plating layer and connecting the first conductor and second conductor layers. The seed layer has a first portion on the surface of the insulating layer, a second portion on an inner wall surface in the opening of the insulating layer, and a third portion on a portion of the first conductor layer exposed by the opening of the insulating layer such that the first portion is thicker than the second portion and the third portion, the second portion has a first film and a second film electrically connected to the first film, and a portion of the first film is formed on the second film.

Abstract: A printed wiring board includes a first conductor layer, a resin insulating layer laminated on the first conductor layer and including resin material and inorganic particles, a second conductor layer formed on a first surface of the insulating layer such that the first conductor layer is facing a second surface of the insulating layer, and a via conductor formed in an opening extending through the insulating layer and connecting the first and second conductor layers. The insulating layer is formed such that the inorganic particles include first inorganic particles partially embedded in the resin and second inorganic particles completely embedded in the resin, the first inorganic particles have first portions protruding from the resin and second portions embedded in the resin respectively, and the first surface of the resin insulating layer includes a surface of the resin and surfaces of the first portions exposed from the surface of the resin.

Abstract: A printed wiring board includes a first conductor layer, a resin insulating layer having an opening extending from a first surface to a second surface of the resin insulating layer and laminated on the first conductor layer, a second conductor layer formed on the first surface of the resin insulating layer such that the first conductor layer is facing the second surface of the resin insulating layer on the opposite side with respect to the first surface, and a via conductor formed in the opening of the resin insulating layer such that the via conductor is connecting the first conductor layer and the second conductor layer and that the via conductor and the second conductor layer include a seed layer and an electrolytic plating layer formed on the seed layer. The seed layer includes an amorphous metal in a range of 5 wt % to 80 wt %.

Abstract: A printed wiring board includes a first resin insulating layer, a second resin insulating layer formed on a surface of the first layer, and a conductor layer formed on the surface of the first layer such that the second layer is covering the conductor layer and that the conductor layer includes first, second, third, fourth, fifth, and sixth circuits such that the third and fourth circuits are sandwiching the first circuit and that the fifth and sixth circuits are sandwiching the second circuit. Widths between the first and third circuits and between the first and fourth circuits are 5 ?m to 14 ?m, and when a width between the second and fifth circuits and a width between the second and sixth circuits is 20 ?m or more, the upper surface of the first circuit, and the upper surface and side walls of the second circuit are formed to have unevenness.

Abstract: A printed wiring board includes a first insulating layer, a conductor layer on the first insulating layer, and a second insulating layer formed on the first insulating layer and covering the conductor layer. The conductor layer includes first, second and third circuits, the first circuit has first width of 15 ?m or less, the first and second circuits have second space between the first and second circuits such that the second space has second width of 14 ?m or less, the first and third circuits have third space between the first and third circuits such that the third space has third width of 20 ?m or more, and the first circuit has first lower and upper surfaces, and second and third side walls such that second angle between the second wall and the first lower surface is larger than third angle between the third wall and the first lower surface.

Abstract: A printed wiring board includes a first resin insulating layer, a conductor layer on the first resin insulating layer, and a second resin insulating layer formed on the first resin insulating layer such that the second resin insulating layer is covering the conductor layer. The conductor layer includes a first circuit having a width of 15 ?m or less and a rectangular cross-sectional shape, a second circuit having a trapezoidal cross-sectional shape, a third circuit, a fourth circuit, a fifth circuit, and a sixth circuit, a space between the first and third circuits has a width of 14 ?m or less, a space between the first and fourth circuits has a width of 14 ?m or less, a space between the second and fifth circuits has a width of 20 ?m or more, and a space between the second and sixth circuits has a width of 20 ?m or more.

Abstract: A printed wiring board includes a first resin insulating layer, a conductor layer on the first resin insulating layer, and a second resin insulating layer formed on the first resin insulating layer such that the second resin insulating layer is covering the conductor layer. The conductor layer includes a first circuit having a width of 15 ?m or less and a rectangular cross-sectional shape, a second circuit having a trapezoidal cross-sectional shape, a third circuit, a fourth circuit, a fifth circuit, and a sixth circuit, a space between the first and third circuits has a width of 14 ?m or less, a space between the first and fourth circuits has a width of 14 ?m or less, a space between the second and fifth circuits has a width of 20 ?m or more, and a space between the second and sixth circuits has a width of 20 ?m or more.

Abstract: A printed wiring board includes a first insulating layer, a conductor layer on the first insulating layer, and a second insulating layer formed on the first insulating layer and covering the conductor layer. The conductor layer includes first, second and third circuits, the first circuit has first width of 15 ?m or less, the first and second circuits have second space between the first and second circuits such that the second space has second width of 14 ?m or less, the first and third circuits have third space between the first and third circuits such that the third space has third width of 20 ?m or more, and the first circuit has first lower and upper surfaces, and second and third side walls such that second angle between the second wall and the first lower surface is larger than third angle between the third wall and the first lower surface.

Abstract: A printed wiring board includes a first resin insulating layer, a second resin insulating layer formed on a surface of the first layer, and a conductor layer formed on the surface of the first layer such that the second layer is covering the conductor layer and that the conductor layer includes first, second, third, fourth, fifth, and sixth circuits such that the third and fourth circuits are sandwiching the first circuit and that the fifth and sixth circuits are sandwiching the second circuit. Widths between the first and third circuits and between the first and fourth circuits are 5 ?m to 14 ?m, and when a width between the second and fifth circuits and a width between the second and sixth circuits is 20 ?m or more, the upper surface of the first circuit, and the upper surface and side walls of the second circuit are formed to have unevenness.