Abstract: An inductor built-in substrate includes a core substrate having an opening, a magnetic resin body having a through hole and including a magnetic resin filled in the opening of the core substrate, and a plating film formed in the through hole of the magnetic resin body and including an electrolytic plating film such that the electrolytic plating film is formed in contact with the magnetic resin body.

Abstract: A printed wiring board includes an insulating layer, a first conductor layer formed on the insulating layer, an adhesive layer formed on the first conductor layer, a resin insulating layer formed on the insulating layer such that the adhesive layer is formed between the first conductor layer and the resin insulating layer, and a second conductor layer formed on the resin insulating layer. The first conductor layer is formed such that the first conductor layer has a smooth upper surface and a smooth side surface and that the adhesive layer has a smooth film formed on the smooth upper and side surfaces, and a protruding part protruding from the smooth film.

Abstract: A planar transformer includes a coil substrate including a flexible substrate and multiple coils formed on the flexible substrate. The coil substrate is formed to have coil parts and coilless parts such that the coil parts have the coils and that the coilless parts do not have the coils, and the coil substrate is folded such that at least one of the coilless parts is sandwiched between two of the coil parts.

Abstract: A wiring substrate includes a core substrate including a core insulating layer, a first conductor layer, a second conductor layer, a first insulating layer, a second insulating layer, a third conductor layer, and a fourth conductor layer. The first conductor layer includes first land and first plane parts, the second conductor layer includes second land and second plane parts, the third conductor layer includes fine wirings and a third plane part, the fourth conductor layer includes fine wirings and a fourth plane part, the substrate includes a through-hole conductor connecting the first and second land parts through the core insulating layer, a first via conductor connecting the first land part and third conductor layer, a second via conductor connecting the second land part and fourth conductor layer, a third via conductor connecting the first and third plane parts, and a fourth via conductor connecting the second and fourth plane parts.

Abstract: A wiring substrate includes a conductor pad, an insulating layer formed on the conductor pad such that the insulating layer is covering the conductor pad and has a through hole, a bump formed on the conductor pad such that the bump is formed in the through hole penetrating through the insulating layer. The conductor pad is formed such that the conductor pad has a connecting surface connected to the bump, a concave part formed on the connecting surface of the conductor pad to the bump, and a convex part formed in the concave part.

Abstract: An inductor built-in substrate includes a core substrate having openings, a magnetic resin filled in the openings of the core substrate, and through-hole conductors formed through the core substrate such that each of the through-hole conductors includes a metal film. The magnetic resin has through holes formed through the magnetic resin such that the through-hole conductors include a group of through-hole conductors formed in the through holes formed through the magnetic resin, and the magnetic resin includes an iron oxide filler in an amount of 60% by weight or more.

Abstract: A printed wiring board includes a first conductor layer, an insulating layer formed on the first conductor layer, a second conductor layer formed on the insulating layer, and a via conductor formed in the insulating layer such that the via conductor is connecting the first and second conductor layers. The insulating layer has opening exposing portion of the first conductor layer such that the via conductor is formed in the opening, the second conductor layer and via conductor are formed such that the second conductor layer and via conductor include a seed layer and an electrolytic plating layer on the seed layer, and the insulating layer includes resin and inorganic particles dispersed in the resin such that the particles include first particles forming inner wall surface in the opening and second particles embedded in the insulating layer and the first particles have shapes different from shapes of the second particles.

Abstract: A method for manufacturing a wiring substrate includes preparing a first support plate having a metal foil formed on surface of a support substrate, forming a wiring substrate on the foil such that the wiring substrate has first surface facing the foil, attaching a second support plate to second surface of the wiring substrate, and separating the support substrate from the foil after attaching the second support plate such that the foil is removed from the first surface and that the first surface is exposed. The wiring substrate has first conductor pads on the first surface, and second conductor pads on the second surface, and the method includes conducting first inspection such that conduction between the second pads is inspected before attaching the second plate to the second surface, and conducting second inspection such that conduction between the first pads is inspected after removing the foil from the first surface.

Abstract: A wiring substrate includes an insulating layer including inorganic fillers and resin, and a conductor layer formed on a surface of the insulating layer and having a conductor pattern. The surface of the insulating layer has an arithmetic average roughness Ra in the range of 0.05 ?m to 0.5 ?m, the conductor layer includes a metal film formed on the surface of the insulating layer, and the inorganic fillers include a first inorganic filler including particles such that each of the particles has a portion of a surface separated from the resin and forming a gap with respect to the resin of the insulating layer and that the metal film of the conductor layer includes part formed in the gap between the first inorganic filler and the resin.

Abstract: A printed wiring board includes a base insulating layer, a conductor layer formed on the base layer and including conductor pads, an underlayer formed on one of the conductor pads and including a metal different from a metal of the conductor layer, a solder resist layer formed on the base layer such that the solder resist layer is covering the conductor layer and has openings exposing the conductor pads, and a bump formed directly on a first conductor pad of the conductor pads and including a base plating layer formed in a first opening of the openings and a top plating layer formed on the base plating layer such that a metal of the base plating layer is same as the metal of the conductor layer. The conductor pads include a second conductor pad such that the second conductor pad is the one of the conductor pads having the underlayer.

Abstract: A wiring substrate includes a first insulating layer, a first conductor layer formed on the first insulating layer, a second insulating layer formed on the first conductor layer, a second conductor layer formed on the second insulating layer, and a via conductor formed in the second insulating layer such that the via conductor is connecting the first and second conductor layers. The second insulating layer has a via hole in which the via conductor is formed, and the via conductor includes a first plating film and a second plating film such that the first plating film has a bottom portion formed at bottom of the via hole and a side portion formed on side of the via hole and separated from the bottom portion by gap and that the second plating film is covering the gap of the first plating film and at least part of the first plating film.

Abstract: A wiring substrate includes a core substrate, and a build-up part formed on the core substrate and including insulating layers and conductor layers. The conductor layers include one or more conductor layers each having a first wiring and a second wiring such that the second wiring has a conductor thickness smaller than a conductor thickness of the first wiring and that a minimum value of a line width of a wiring pattern of the second wiring is smaller than a minimum value of a line width of a wiring pattern of the first wiring.

Abstract: A printed wiring board includes an insulating layer, and a conductor layer including a solid layer and wirings. The solid layer has an opening part. The wirings are formed in the opening part. The opening part includes first and second opening parts. The wirings include first and second wirings. The first wiring has a first land, a first portion, and a second portion. The second wiring has a second land, a third portion, and a fourth portion extending in parallel to the second portion. A first boundary between the first and second portions is in the second opening part. The first portion is bending at the first boundary and increasing distance between the first and second wirings. A second boundary between the third and fourth portions is in the second opening part. The third portion is bending at the second boundary and increasing distance between the first and second wirings.

Abstract: A coil substrate includes a flexible substrate having a first end and a second end on the opposite side with respect to the first end, and coils formed on the flexible substrate such that the coils are positioned substantially in a row between the first end and second end of the flexible substrate. The coils are formed such that the number of coils is K and that the coils include the first coil positioned close to the first end and the K-th coil positioned to form a predetermined distance between the K-th coil and the second end, where K is an integer equal to or greater than 2.

Abstract: A method for manufacturing a multilayer wiring substrate includes forming a resist layer having mask pattern, forming a conductor layer having conductor pattern using the resist layer, removing the resist layer, forming an insulating layer on the conductor layer such that the insulating layer is laminated on the conductor layer, forming a subsequent resist layer having mask pattern such that the subsequent resist layer is formed on the insulating layer, and forming a subsequent conductor layer having conductor pattern using the subsequent resist layer. The forming of the resist layer includes conducting first correction in which formation position of entire mask pattern of the resist layer is corrected with respect to reference position, and conducting second correction in which shape of the mask pattern of the resist layer is corrected with respect to reference shape, and the forming of the subsequent resist layer does not include conducting the second correction.

Abstract: A coil substrate includes a flexible substrate, and coils formed on the flexible substrate such that the coils are positioned substantially in a raw and that each coil has a center space and wirings surrounding the center space. The coils are formed such that each coil includes first wirings on a first surface of the flexible substrate, second wirings on a second surface of the flexible substrate on the opposite side with respect to the first surface, and via conductors penetrating through the flexible substrate and connecting the first and second wirings, and the coils are positioned such that a m-th coil has the second wirings positioned below the center space of a (m+1)-th coil and that a (m+2)-th coil has the first coils positioned on the center space of a (m+1)-th coil, where in is an integer equal to or greater than 1.

Abstract: A method of inspecting a printed wiring board includes preparing a printed wiring board having product and inspection regions such that the board has inner-layer lands in the regions, forming vias on the inner-layer lands in the regions, forming outer peripheral part(s) in the wiring board such that the outer peripheral part(s) expose outer peripheral portion(s) of the inner-layer land in the inspection region, determining a center coordinate of the inner-layer land in the inspection region based on a position of the outer peripheral part(s), determining a center coordinate of the via(s) in the inspection region based on a shape of the via(s) in the inspection region, determining a misalignment amount based on a distance between the center coordinate of the inner-layer land and the center coordinate of the via(s) in the inspection region, and determining alignment accuracy between the via and the inner-layer land based on the misalignment amount.

Abstract: A printed wiring board includes a resin insulating layer, a metal post formed in the insulating layer and protruding from first surface of the insulating layer, a conductor layer formed on second surface of the insulating layer, and a via conductor penetrating through the insulating layer and connecting the metal post and conductor layer. The metal post has a protruding portion protruding from the first surface of the insulating layer and an embedded portion connected to the protruding portion and embedded in the insulating layer such that the protruding portion does not extend onto the insulating layer, and the metal post has upper and side surfaces such that the side surface has unevenness including a first unevenness on side surface of the protruding portion and a second unevenness formed on side surface of the embedded portion and having a size that is larger than a size of the first unevenness.

Abstract: A wiring substrate includes an insulating layer including inorganic filler particles and resin, and a conductor layer including a metal film formed on a surface of the insulating layer and having a conductor pattern. The inorganic filler particles include first inorganic filler particles such that each of the first inorganic filler particles has a portion exposed on the surface of the insulating layer and is at least partially separated from the resin, the conductor layer is formed such that a part of the metal film is between the first inorganic filler particles and the resin from the surface of the insulating layer and that a distance between the surface of the insulating layer and the surface of the insulating layer at a deepest part of the part of the metal film is in the range of 0.1 ?m to 0.5 ?m.

Abstract: A wiring substrate includes a first conductor pattern, a second conductor pattern, an insulating layer interposed between the first and second patterns and having a through hole, and a plating conductor integrally formed with the second pattern and filling the through hole in the insulating layer such that the plating conductor is in contact with the first pattern. The through hole has an expansion part such that an opening width of the through hole on the first pattern side is widened, and the plating conductor includes a first plating film directly formed on inner wall of the through hole and a second plating film formed on the first plating film such that the minimum thickness of the first plating film in the expansion part is in the range of 55% to 95% of the minimum thickness of the first plating film in the through hole other than the expansion part.