A wiring substrate includes an insulating layer including resin and filler particles, and an embedded wiring layer including wirings and embedded in the insulating layer such that the wirings are filling grooves formed on a surface of the insulating layer, respectively. The embedded wiring layer is formed such that the inter-wiring distance between the closest two wirings of the wirings in the embedded wiring layer is in the range of 2 μm to 8 μm, and the insulating layer is formed such that the maximum particle size of the filler particles is 50% or less of the inter-wiring distance.

A wiring board includes a base material, a through hole that is formed in the base material, a magnetic member that is embedded in the through hole, and a plating film that covers end faces of the magnetic member exposed from the through hole. The magnetic member includes a conductor wire that is covered by a magnetic body. A wiring board manufacturing method includes forming a through hole in a base material, forming a magnetic member by covering a conductor wire by a magnetic body, embedding the magnetic member in the through hole, and forming a plating film that covers end faces of the magnetic member exposed from the through hole.

A wiring board includes a first interconnect structure including a first interconnect layer, and a first insulating layer including a non-photosensitive thermosetting resin as a main component thereof, a second interconnect structure including second interconnect layers, and second insulating layers including a photosensitive resin as a main component thereof, and laminated on the first interconnect structure, and an encapsulating resin layer including a non-photosensitive thermosetting resin as a main component thereof, and laminated on an uppermost second insulating layer. An uppermost second interconnect layer includes a pad protruding from the uppermost second insulating layer. The encapsulating resin layer exposes a top surface of the pad, and covers at least a portion of a side surface of the pad. Thermal expansion coefficients of the first insulating layer and the encapsulating resin layer are lower than that of the second insulating layers.

In manufacturing a printed circuit board using a semi-additive method, a removal liquid that has been used in removing a nickel-chromium-containing layer (5) is regenerated by contacting the removal liquid with a chelate resin having a functional group represented by a following formula (1) :

##STR00001##

where a plurality of Rs are identical divalent hydrocarbon groups having 1 to 5 carbons, and a portion of hydrogen atoms may be substituted with halogen atoms.

Electrical circuitry is produced on the surface of an organic polymer. The electrical circuitry is produced on a support, and a polymerizable composition is brought into contact with the support and the circuitry. The polymerizable composition is polymerized while in contact with support and the circuitry to produce a solid, organic polymer. The electrical circuitry becomes adhered to and partially embedded in a surface of the solid organic polymer. The support may be removed subsequent to the polymerization step to expose the circuitry at the surface of the solid organic polymer.

A wiring substrate includes an insulating layer including resin and filler particles, and an embedded wiring layer including wirings and embedded in the insulating layer such that the wirings are filling grooves formed on a surface of the insulating layer, respectively. The embedded wiring layer is formed such that the smallest line width of the wirings in the embedded wiring layer is in the range of 2 μm to 8 μm, and the insulating layer is formed such that the maximum particle size of the filler particles is 50% or less of the smallest line width of the wirings in the embedded wiring layer.

The casing of an electronic control device includes a casing-side contact surface in contact with the end of a printed-circuit board. A cover includes a cover-side contact surface holding the end of the printed-circuit board together with the casing-side contact surface by being in contact with the end of the printed-circuit board. In the printed-circuit board, a held portion held between the casing-side contact surface and the cover-side contact surface is provided with a through-hole via.

Provided are a polyimide film capable of reducing a dielectric constant of a substrate and reducing a thickness and forming a stable via with a low possibility of disconnection, a method for manufacturing the same, and an FPCB including the same. A polyimide film according to an exemplary embodiment of the present invention includes a polyimide layer and a plurality of fluororesin particles dispersed in the polyimide layer. The fluororesin particles have a spherical or flat shape.

An interconnect substrate includes a core layer including a resin layer mainly composed of a non-photosensitive thermosetting resin and a through interconnect extending through the resin layer, the core layer having no reinforcement member contained therein, a first interconnect structure laminated on a first side of the core layer and including first interconnect layers and first insulating layers mainly composed of a photosensitive resin, and a second interconnect structure laminated on a second side of the core layer and including second interconnect layers and a single second insulating layer mainly composed of a photosensitive resin, wherein the first interconnect layers are electrically connected to the second interconnect layers via the through interconnect, wherein the core layer has greater rigidity than the first interconnect structure and the second interconnect structure, and wherein a thickness of the second interconnect structure is greater than a thickness of each of the first insulating layer.

A resin composition, a prepreg, and a printed circuit board are provided. The resin composition is used to form a dielectric substrate layer. The resin composition includes a polymeric based material and fillers. Based on a total volume of the resin composition being 100 vol %, the resin composition includes 10 vol % to 60 vol % of the polymeric based material and 1 vol % to 80 vol % of the fillers. The fillers include hollow fillers, and the hollow fillers include a first hollow filler. A material of the first hollow filler is silicon dioxide.