Provided are flexible hybrid interconnect circuits and methods of forming thereof. A flexible hybrid interconnect circuit comprises multiple conductive layers, stacked and spaced apart along the thickness of the circuit. Each conductive layer comprises one or more conductive elements, one of which is operable as a high frequency (HF) signal line. Other conductive elements, in the same and other conductive layers, form an electromagnetic shield around the HF signal line. Some conductive elements in the same circuit are used for electrical power transmission. All conductive elements are supported by one or more inner dielectric layers and enclosed by outer dielectric layers. The overall stack is thin and flexible and may be conformally attached to a non-planar surface. Each conductive layer may be formed by patterning the same metallic sheet. Multiple pattern sheets are laminated together with inner and outer dielectric layers to form a flexible hybrid interconnect circuit.

A printed circuit board has multiple stacked layers laminated together. A through hole is formed through the laminated stack, and plating is applied to the side walls of the though hole, thereby forming a plated through hole. Second through holes are then formed through the laminated stack, where each second through hole overlaps an edge of the plated through hole. By aligning the second through holes at the edge of the plated through hole, the plating of the plated through hole coincident with each second through hole is removed, thereby separating the plated through hole into two separate circuit paths. Forming second through holes in this manner effectively splits the circuit path of the plated through hole into multiple separate circuit paths, which increases the circuit density of the printed circuit board.

A flexible circuit board includes two first wiring boards, a first adhesive, and a first conductive structure. Each of the two first wiring boards includes a first bent portion, and two first bent portions of the two wiring boards is connected to each other. The first adhesive layer is sandwiched between the two first bent portions. The first conductive structure penetrates the two first bent portions and the first adhesive layer and electrically connects the two first bent portions.

A wiring board of the present invention includes an insulating board including a core insulating plate and an insulating layer laminated on at least one surface of the insulating plate. A plurality of code information reading pads formed of a conductor layer are disposed on a surface of the insulating layer formed uppermost. A common conductor is disposed oppositely to the code information reading pads by interposing therebetween the insulating layer formed uppermost. At least one of the code information reading pads and the common conductor are electrically connected to each other through a via conductor penetrating through the insulating layer formed uppermost.

A through wiring substrate comprises a substrate having a pair of principal surfaces and a through hole penetrating between the pair of principal surfaces, the pair of principal surfaces and an inner surface of the through hole being electrically insulative; a through electrode provided on the inner surface of the through hole; a first wiring layer provided on one of the principal surfaces and connected to the through electrode; a second wiring layer provided on the other of the principal surfaces and connected to the through electrode; an underlying metal layer provided between the one of the principal surfaces and the first wiring layer; and catalyst metal particles existing between the underlying metal layer and the first wiring layer and between the through electrode and the inner surface of the through hole.

Through hole filling pastes which include a magnetic powder (A), an epoxy resin (B), and a curing agent (C), in which the magnetic powder (A) is surface-treated with a surface treating agent containing at least one element selected from Si, Al, and Ti, are capable of achieving a cured product excellent in plating adhesion.

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.

A printed circuit board deformable in both length and width includes a first conductive circuit layer, a second conductive circuit layer, an elastic film, and conductive via holes. The first conductive circuit layer includes first conductive circuits. First honeycomb holes are defined on the first conductive circuits. The second conductive circuit layer faces away from the first conductive circuit layer, the second conductive circuit layer comprises second conductive circuits, second honeycomb holes being defined on the second conductive circuits, each of the second honeycomb holes corresponds to one of the first honeycomb holes. The first conductive circuits are embedded in the elastic film. Each of the conductive via holes corresponds to one first honeycomb holes.

An epoxy resin exhibits a small change in volume after thermal history, is excellent in low thermal expansion and low moisture absorption, and has high heat resistance, in terms of a cured product obtained therefrom; a curable resin composition; a cured product which has all the above properties; a semiconductor encapsulating material; a semiconductor device; a prepreg; a circuit board; a buildup film; a buildup substrate; a fiber-reinforced composite material; and a molded article. The present invention is characterized by an epoxy resin, characterized by including as essential components, a cresol-naphthol co-condensed novolac type epoxy resin (A), a naphthol glycidyl ether compound (B), and one or more xanthene compounds (C) selected from the group of compounds represented by the following structural formulae (1) to (3), wherein the content of the xanthene compound(s) (C) is from 0.1% to 5.5% in terms of area ratio in a GPC measurement.

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A laminated uncured sheet of the present disclosure has a structure in which resin sheet layers and resin layers are alternately laminated and a through hole penetrating in the laminating direction is formed, wherein the resin sheet layers are formed with a thermosetting resin composition containing a thermosetting resin as a main component, the resin layers are formed with a thermoplastic resin composition containing a thermoplastic resin, and the thermoplastic resin composition is adhered to the inner wall surface of the resin sheet layer part in the through hole.