A flexible printed wiring board according to an aspect of the present disclosure is a flexible printed wiring board including a base film and a plurality of wiring lines disposed on a front surface of the base film. Each of the wiring lines has a front end surface extending in a longitudinal direction of the wiring line and two side surfaces extending in the longitudinal direction, and the side surfaces have an arithmetical mean roughness Ra of 0.05 .Math.m to 2.0 .Math.m. The wiring lines have an average height of 40 .Math.m to 120 .Math.m. The wiring lines have an average spacing of 1 .Math.m to 30 .Math.m.

The present disclosure generally relates to printed circuit boards or printed circuit board assemblies for fiber optic communications. In one example, an optoelectronic assembly may include a printed circuit board including a laser-roughened area, at least one optoelectronic component coupled to a surface of the printed circuit board, and an optical component attached to the printed circuit board. The coupling area may be defined by the optical component contacting the printed circuit board, and the laser-roughened area may be positioned entirely within the coupling area defined by the optical component contacting the printed circuit board.

The insertion loss of a multilayer substrate and an antenna element is reduced. A multilayer substrate according to an embodiment of the present disclosure includes a multilayer body, a wire conductor, and a first ground electrode. The multilayer body is formed by dielectric layers being layered. The wire conductor is formed in the multilayer body, and a radio frequency signal passes through the wire conductor. The first ground electrode is formed in or on the multilayer body and includes a first surface that faces the wire conductor. The first surface includes a first region and a second region. The surface roughness of the first region is lower than the surface roughness of the second region. The first region overlaps at least part of the wire conductor in plan view in a direction normal to the first ground electrode.

A component carrier includes a stack with at least one electrically conductive layer structure, at least one electrically insulating layer structure, a cavity delimited at a bottom side at least partially by a top side of a stepped metal structure of the at least one electrically conductive layer structure, and a component embedded in the cavity and arranged on the stepped metal structure. A bottom side of the stepped metal structure has a flat surface extending continuously along at least one horizontal direction.

A wiring board including a component mounting portion with an increased strength is provided. In addition, an electronic device and an electronic module with high reliabilities are provided. The wiring board includes a base having a first face and a conductor positioned on the first face. The conductor has a region in which a plurality of first protrusions are positioned on a surface of the conductor, the plurality of first protrusions protruding in a same oblique direction that is oblique to a direction normal to the first face. The electronic device and the electronic module include the above-described wiring board and an electronic component mounted on the wiring board.

The present invention includes a method of fabricating an integrated RF power condition capacitor with a capacitance greater than or equal to 1 nf and less than 1 mm.sup.2, and a device made by the method.

A sheet material includes a resin layer containing a binder and polypyrrole particles, an electroless plating film provided on the side of one main surface of the resin layer and including first electroless plating films and a second electroless plating film, and a transparent base material provided on the side of the other main surface of the resin layer.

A manufacturing method of copper foil and circuit board assembly for high frequency transmission are provided. Firstly, a raw copper foil having a predetermined surface is produced by an electrolyzing process. Subsequently, a roughened layer including a plurality of copper particles is formed on the predetermined surface by an arsenic-free electrolytic roughening treatment and an arsenic-free electrolytic surface protection treatment. Thereafter, a surface treatment layer is formed on the roughened layer, and the roughened layer is made of a material which includes at least one kind of non-copper metal elements and the concentration of the non-copper metal elements is smaller than 400 ppm. By controlling the concentration of the non-copper elements, the resistance of the copper foil can be reduced.

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 μm 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 μm or less, a space between the first and fourth circuits has a width of 14 μm or less, a space between the second and fifth circuits has a width of 20 μm or more, and a space between the second and sixth circuits has a width of 20 μm or more.

Provided is a copper foil provided with a carrier in which the laser hole-opening properties of the ultrathin copper layer are good and which is suitable for producing a high-density integrated circuit substrate. A copper foil provided with a carrier having, in order, a carrier, an intermediate layer, and an ultrathin copper layer, wherein the specular gloss at 60° in an MD direction of the intermediate layer side surface of the ultrathin copper layer is 140 or less.