Abstract: A first coil portion is formed in a first coil region of an upper surface of an insulating layer, and a second coil portion is formed on a lower surface of the insulating layer. A second terminal is formed at a position outside the first coil region. One or more intersection regions, in which a path, extending from an inner end of the first coil portion to the second terminal, intersects the first coil portion, are provided on the upper surface. The first coil portion is parted in each intersection region. A second lead portion passes between one portion and another portion of the first coil portion parted in said each intersection region and extends from the inner end of the first coil portion to the second terminal. The first coil portion and the second coil portion are connected together in parallel via through holes formed in the insulating layer.

Abstract: The communication module includes a housing, an element disposed in the housing and generates electric power by a wireless system by induced electricity, a communication circuit that operates based on electric power generated by the element, and a sheet member disposed between the housing and the element and having thermal conductivity and electrical insulation.

Abstract: A first coil portion is formed on a first coil region of an upper surface, and a second coil portion is formed on a lower surface, of an insulating layer. A second terminal is formed at a position outside of the first coil region. One or plurality of intersection regions in which a path extending from an inner end of the first coil portion to the second terminal intersects with the first coil portion are provided on the upper surface. The first coil portion is parted in each intersection region. A second lead portion passes between one and the other portions of the first coil portion parted in each intersection region and extends from the inner end of the first coil portion to the second terminal. The first and second coil portions are connected in parallel to each other via a plurality of through holes formed in the insulating layer.

Abstract: A differential transmission path composed of a pair of transmission lines is formed on an upper surface of a base insulating layer. A ground conductor layer is formed on a lower surface of the base insulating layer. The ground conductor layer is opposite to the differential transmission path with the base insulating layer sandwiched therebetween. A spacing between the transmission lines at a part of the differential transmission path is smaller than a spacing between the transmission lines at another part of the differential transmission path. A thickness of a part of the ground conductor layer overlapping the part of the differential transmission path is smaller than the thickness of another part of the ground conductor layer overlapping the another part of the differential transmission path.

Abstract: An FPC board includes a base insulating layer. A plurality of wiring traces are formed on the base insulating layer. The adjacent wiring traces are arranged at a distance d from each other, and each wiring trace has a predetermined width and a thickness t1. Each transmission line pair is constituted by the two adjacent wiring traces of the plurality of wring traces. A ratio of the thickness t1 of the wiring trace to the distance d between the adjacent wiring traces is set to 0.8 or more. A cover insulating layer may be formed on the base insulating layer to cover the wiring traces. A metal layer having a predetermined thickness may be provided on a back surface of the base insulating layer. Furthermore, a differential impedance of each transmission line pair may be set to 100 ?.

Abstract: A multi-layer structure including a base insulating layer and a thin metal film layer (seed layer) is prepared. A plating resist layer is formed to have a prescribed pattern on the upper surface of the thin metal film layer. A metal plating layer is formed on the thin metal film layer exposed by electroplating. Then, the plating resist layer is removed, and the thin metal film layer in the region having the plating resist layer is removed. In this way, a conductive pattern including the thin metal film layer and the metal plating layer is formed. The upper surface of the base insulating layer in the region without the conductive pattern is subjected to roughening treatment. A cover insulating layer is formed on the upper surfaces of the base insulating layer and the conductive pattern. In this way, a printed circuit board is completed.

Abstract: A differential transmission path composed of a pair of transmission lines is formed on an upper surface of a base insulating layer. A ground conductor layer is formed on a lower surface of the base insulating layer. The ground conductor layer is opposite to the differential transmission path with the base insulating layer sandwiched therebetween. A spacing between the transmission lines at a part of the differential transmission path is smaller than a spacing between the transmission lines at another part of the differential transmission path. A thickness of a part of the ground conductor layer overlapping the part of the differential transmission path is smaller than the thickness of another part of the ground conductor layer overlapping the another part of the differential transmission path.

Abstract: An FPC board includes a base insulating layer. A plurality of wiring traces are formed on the base insulating layer. The adjacent wiring traces are arranged at a distance d from each other, and each wiring trace has a predetermined width and a thickness t1. Each transmission line pair is constituted by the two adjacent wiring traces of the plurality of wring traces. A ratio of the thickness t1 of the wiring trace to the distance d between the adjacent wiring traces is set to 0.8 or more. A cover insulating layer may be formed on the base insulating layer to cover the wiring traces. A metal layer having a predetermined thickness may be provided on a back surface of the base insulating layer. Furthermore, a differential impedance of each transmission line pair may be set to 100 ?.

Abstract: A multi-layer structure including a base insulating layer and a thin metal film layer (seed layer) is prepared. A plating resist layer is formed to have a prescribed pattern on the upper surface of the thin metal film layer. A metal plating layer is formed on the thin metal film layer exposed by electroplating. Then, the plating resist layer is removed, and the thin metal film layer in the region having the plating resist layer is removed. In this way, a conductive pattern including the thin metal film layer and the metal plating layer is formed. The upper surface of the base insulating layer in the region without the conductive pattern is subjected to roughening treatment. A cover insulating layer is formed on the upper surfaces of the base insulating layer and the conductive pattern. In this way, a printed circuit board is completed.

Abstract: A multi-layer structure including a base insulating layer and a thin metal film layer (seed layer) is prepared. A plating resist layer is formed to have a prescribed pattern on the upper surface of the thin metal film layer. A metal plating layer is formed on the thin metal film layer exposed by electroplating. Then, the plating resist layer is removed, and the thin metal film layer in the region having the plating resist layer is removed. In this way, a conductive pattern including the thin metal film layer and the metal plating layer is formed. The upper surface of the base insulating layer in the region without the conductive pattern is subjected to roughening treatment. A cover insulating layer is formed on the upper surfaces of the base insulating layer and the conductive pattern. In this way, a printed circuit board is completed.

Abstract: A photosensitive resin composition for a flexible circuit board capable of suppressing warpage occurrence after heat curing, and a flexible circuit board obtained by using the same. The photosensitive resin composition includes (A) a carboxyl-group containing linear polymer having a glass transition temperature of not more than 55° C. obtained by addition polymerizing an ethylenic unsaturated compound; (B) a polymerizable compound containing an ethylenic unsaturated group; and (C) a photopolymerization initiator.

Abstract: A photosensitive resin composition for a flexible circuit board having excellent flame retardancy and with non-halogenation for consideration of environmental aspects, and a flexible circuit board obtained by using the same. The photosensitive resin composition includes (A) a linear polymer containing a carboxyl group obtained by addition polymerizing an ethylenic unsaturated compound; (B) a polymerizable compound containing an ethylenic unsaturated group; (C) a photopolymerization initiator: and (D) a phosphorated epoxy resin containing phosphorous atom at not less than 2% by weight based on a total molecular weight thereof.

Abstract: A multi-layer structure including a base insulating layer and a thin metal film layer (seed layer) is prepared. A plating resist layer is formed to have a prescribed pattern on the upper surface of the thin metal film layer. A metal plating layer is formed on the thin metal film layer exposed by electroplating. Then, the plating resist layer is removed, and the thin metal film layer in the region having the plating resist layer is removed. In this way, a conductive pattern including the thin metal film layer and the metal plating layer is formed. The upper surface of the base insulating layer in the region without the conductive pattern is subjected to roughening treatment. A cover insulating layer is formed on the upper surfaces of the base insulating layer and the conductive pattern. In this way, a printed circuit board is completed.

Abstract: A wired circuit board having a terminal portion formed as a flying lead that can provide enhanced strength of the conductive pattern, both sides of which are exposed, by simple construction to effectively prevent disconnection of the conductive pattern. The wired circuit board having the terminal portion formed as the flying lead in which the both sides of the conductive pattern are exposed includes, in crossing areas where ends of a cover-side opening and ends of a base-side opening and the conductive pattern are crossed each other, (i) the widened portions formed in the conductive pattern or (ii) cover-side projections and base-side projections formed in the cover layer and the base layer, respectively.

Abstract: In a junction flexible wiring circuit board used for performing junction between a suspension board for mounting a magnetic head of a hard disk drive thereon and a control circuit board for operating the magnetic head, a metal layer is formed on at least one of a surface of an electrically insulating base layer and a surface of an electrically insulating cover layer.

Abstract: In a junction flexible wiring circuit board used for performing junction between a suspension board for mounting a magnetic head of a hard disk drive thereon and a control circuit board for operating the magnetic head, a metal layer is formed on at least one of a surface of an electrically insulating base layer and a surface of an electrically insulating cover layer.