A wiring board includes a core layer having a first through hole formed therein, a magnetic resin filled inside the first through hole, a second through hole formed in the magnetic resin, and a plating film covering an inner wall surface of the second through hole. The plating film includes an electroless plating film, and an electrolytic plating film. The electroless plating film makes direct contact with an inner wall surface of the second through hole.

An antenna device includes a resin multilayer board in which a plurality of resin sheets are stacked, and a coil conductor provided in the resin multilayer board. A plurality of line portions of the coil conductor are provided on a lower surface of the resin sheet. When a magnetic material core is preliminarily pressure-bonded to the resin sheet, the magnetic material core is fractured along the line portions and cracks occur. Thus, the resin sheet with the magnetic material core in which the cracks have been formed is fully pressure-bonded together with the other resin sheets.

A printed circuit board package structure includes a substrate, plural ring-shaped magnetic elements, a support layer, and first conductive layers. The substrate has two opposite first and second surfaces, first ring-shaped recesses, and first grooves. Each of the first ring-shaped recesses is communicated with another first ring-shaped recess through at least one of the first grooves, and at least two of the first ring-shaped recesses are communicated with a side surface of the substrate through the first grooves to form at least two openings. The ring-shaped magnetic elements are respectively located in the first ring-shaped recesses. The support layer is located on the first surface, and covers the first ring-shaped recesses and the first grooves. The support layer and the substrate have through holes. The first conductive layers are respectively located on surfaces of support layer and substrate facing the through holes.

A high-frequency signal transmission line includes a body including a plurality of first base layers and a second base layer stacked on one another in a stacking direction. The first base layers have a first relative permeability, and the second base layer has a relative permeability lower than the first relative permeability. A first signal line and a second signal line extending along the first signal line are provided in the body. In a cross section perpendicular or substantially perpendicular to a first direction in which the first signal line extends, the second base layer occupies at least a portion of an area between the first signal line and the second signal line. In the cross section perpendicular or substantially perpendicular to the first direction, the plurality of first base layers define a loop enclosing the first signal line, the second signal line and the second base layer.

In a printed circuit board (1) comprising a plurality of insulating layers and conductive layers, and comprising at least one cavity (7) at least one electromagnetic coil (8) is arranged on an outer layer (4) of the printed circuit board (1) and cooperates with a permanent magnet (6) arranged inside the at least one cavity (7).

A power conversion device includes a multilayer board including conductive layers that form a primary-side coil and a secondary-side coil of a transformer; and a circuit board electrically connected to the multilayer board, having a first conversion circuit formed therein or thereon. The multilayer board includes a transformer region in which the transformer is formed; a core member disposed in the transformer region and around the primary-side coil and secondary-side coil are wound; a circuit formed region which is adjacent to the transformer region and a second conversion circuit is formed, the second conversion circuit being electrically connected to the primary-side coil or the secondary-side coil; and a terminal portion which is electrically connected to the secondary-side coil or the primary-side coil. The first conversion circuit is electrically connected to the transformer via the terminal portion. One of the coils has a smaller number of turns than the other coil.

A substrate with built-in passive element includes passive elements and a substrate. The passive elements include at least one of a capacitor, an inductor, a resistor, a signal transmission element or an optical waveguide element. The capacitor, the inductor, the resistor, the signal transmission element or the optical waveguide element has a functional element filled in a groove-like or hole-like element forming region provided in the substrate along a thickness direction thereof. The functional element has a Si—O bond region obtained by reacting Si particles with an organic Si compound.

A wiring board includes an insulating base including a first principal surface, a second principal surface opposite to the first principal surface, and a first through hole penetrating the insulating base from the first principal surface to the second principal surface, a functional material provided inside the first through hole, a first insulating layer covering the first principal surface, and a first surface of the functional material, and a second insulating layer covering the second principal surface, and a second surface of functional material. A second through hole is formed in the first insulating layer, the functional material, and the second insulating layer, and a conductive layer is formed on a wall surface of the second through hole.

An isolated converter reduced in size compared with a conventional isolated converter and having a high heat dissipation characteristic is provided. The isolated converter includes a multilayer substrate having a first through hole and a magnetic core partially passing through the first through hole. The multilayer substrate includes a first conductor pattern formed at a position overlapping the magnetic core on a second surface when viewed from a direction orthogonal to a first surface, a second conductor pattern formed between the first surface and the second surface at a position overlapping the magnetic core and the first conductor pattern when viewed from the direction orthogonal to the first surface, at least one thermal conductive member formed on the first conductor pattern and having a portion disposed between the multilayer substrate and the magnetic core, and an electric insulating layer electrically insulating the first conductor pattern from the second conductor pattern.

A circuit board with a measure against high frequency noise includes: an interconnect substrate having an interconnect pattern to which an IC which is a source of high frequency noise is electrically connected; a pair of lands provided on a mounting surface of the interconnect substrate; and a chip component having a body composed of a magnetic body (i.e., ferrite) in a rectangular parallelepiped, and a pair of external electrodes provided at opposite ends of the body, the pair of external electrodes being connected to the pair of lands, the body being disposed on the interconnect pattern, as observed in a direction perpendicular to the mounting surface.