Abstract: A method for manufacturing a rigid-flexible multilayer wiring board includes a step of forming a release layer such that the release layer covers a flexible portion forming region of a principal surface of a first thermoplastic resin sheet, a step of conducting surface modification on the principal surface of the first thermoplastic resin sheet while using the release layer as a mask, a step of laminating a second thermoplastic resin sheet such that the second thermoplastic resin sheet covers the release layer to form a laminate including the first and second thermoplastic resin sheets, a step of press-bonding the laminate, a step of forming a cut from at least either one of upper and lower surfaces of the laminate toward an outline of the release layer when seen in a plan view, and a step of removing a portion surrounded by the cut.

Abstract: A method of manufacturing a resin multilayer substrate with a cavity, includes stacking insulation substrates including thermoplastic resins and thermocompression-bonding the insulation substrates. At least one of the insulation substrates is formed by affixing a peelable carrier film to one main surface of the insulation substrate, making a cut in the insulation substrate having the carrier film affixed thereto, the cut being designed to form the cavity, penetrating the insulation substrate in a thickness direction and not penetrating the carrier film in a thickness direction, and removing the carrier film and a portion of the insulation substrate that is cut out by the cut.

Abstract: A substrate includes a built-in component that suppresses resin flow occurring in the case of thermocompression bonding in a region where vias and wiring conductors are provided and that reduces the occurrence of via defects and wiring-conductor defects. The resin flow occurring in an outer side portion of a frame-shaped electrode is suppressed in the case of thermocompression bonding by encircling the periphery of a built-in component with the frame-shaped electrode. Because of this structure, the occurrence of defects in vias and wiring conductors arranged in an outer side portion of the frame-shaped electrode may be reduced.

Abstract: The present invention provides a multilayer circuit board that includes a plurality of resin layers, conductive wiring layers, and via-hole conductors. Each of the resin layers includes a resin sheet containing a resin and a conductive wiring layer disposed on at least one surface of the resin sheet. The via-hole conductors contain an intermetallic compound having a melting point of 300° C. or more produced by a reaction between a first metal composed of Sn or an alloy containing 70% by weight or more Sn and a second metal composed of a Cu—Ni alloy or a Cu—Mn alloy. The second metal has a higher melting point than the first metal.

Abstract: A method for manufacturing a rigid-flexible multilayer wiring board includes a step of forming a release layer such that the release layer covers a flexible portion forming region of a principal surface of a first thermoplastic resin sheet, a step of conducting surface modification on the principal surface of the first thermoplastic resin sheet while using the release layer as a mask, a step of laminating a second thermoplastic resin sheet such that the second thermoplastic resin sheet covers the release layer to form a laminate including the first and second thermoplastic resin sheets, a step of press-bonding the laminate, a step of forming a cut from at least either one of upper and lower surfaces of the laminate toward an outline of the release layer when seen in a plan view, and a step of removing a portion surrounded by the cut.

Abstract: A method for manufacturing a rigid-flexible multilayer wiring board includes a step of forming a release layer such that the release layer covers a flexible portion forming region of a principal surface of a first thermoplastic resin sheet, a step of conducting surface modification on the principal surface of the first thermoplastic resin sheet while using the release layer as a mask, a step of laminating a second thermoplastic resin sheet such that the second thermoplastic resin sheet covers the release layer to form a laminate including the first and second thermoplastic resin sheets, a step of press-bonding the laminate, a step of forming a cut from at least either one of upper and lower surfaces of the laminate toward an outline of the release layer when seen in a plan view, and a step of removing a portion surrounded by the cut.

Abstract: A method of manufacturing a resin multilayer substrate with a cavity, includes stacking insulation substrates including thermoplastic resins and thermocompression-bonding the insulation substrates. At least one of the insulation substrates is formed by affixing a peelable carrier film to one main surface of the insulation substrate, making a cut in the insulation substrate having the carrier film affixed thereto, the cut being designed to form the cavity, penetrating the insulation substrate in a thickness direction and not penetrating the carrier film in a thickness direction, and removing the carrier film and a portion of the insulation substrate that is cut out by the cut.

Abstract: The present invention provides a multilayer circuit board that includes a plurality of resin layers, conductive wiring layers, and via-hole conductors. Each of the resin layers includes a resin sheet containing a resin and a conductive wiring layer disposed on at least one surface of the resin sheet. The via-hole conductors contain an intermetallic compound having a melting point of 300° C. or more produced by a reaction between a first metal composed of Sn or an alloy containing 70% by weight or more Sn and a second metal composed of a Cu—Ni alloy or a Cu—Mn alloy. The second metal has a higher melting point than the first metal.

Abstract: A resin circuit board includes a layered structure of resin layers and conductor layers, has significantly reduced and minimized warping and distortion, and has a precise shape. A second conductor layer is disposed between a resin layer and a first conductor layer made of a metal. The resin layer and the second conductor layer have a higher thermal expansion coefficient than the first conductor layer such that the thermal expansion coefficient changes gradually, allowing a stress resulting from a difference in thermal expansion coefficient to be relieved.

Abstract: A reliable flexible board prevents disconnection from occurring in a conductor layer in a stacking process or during use of a product that repeatedly causes deformation. The flexible board includes resin layers and conductor layers that are alternately stacked on top of one another, wherein each of the conductor layers includes a first conductor layer made of a first metal and a second conductor layer made of a second metal disposed between one of the resin layers and the first conductor layer, the second metal having a higher ductility than the first metal.

Abstract: A method for manufacturing a rigid-flexible multilayer wiring board includes a step of forming a release layer such that the release layer covers a flexible portion forming region of a principal surface of a first thermoplastic resin sheet, a step of conducting surface modification on the principal surface of the first thermoplastic resin sheet while using the release layer as a mask, a step of laminating a second thermoplastic resin sheet such that the second thermoplastic resin sheet covers the release layer to form a laminate including the first and second thermoplastic resin sheets, a step of press-bonding the laminate, a step of forming a cut from at least either one of upper and lower surfaces of the laminate toward an outline of the release layer when seen in a plan view, and a step of removing a portion surrounded by the cut.

Abstract: A reliable flexible board prevents disconnection from occurring in a conductor layer in a stacking process or during use of a product that repeatedly causes deformation. The flexible board includes resin layers and conductor layers that are alternately stacked on top of one another, wherein each of the conductor layers includes a first conductor layer made of a first metal and a second conductor layer made of a second metal disposed between one of the resin layers and the first conductor layer, the second metal having a higher ductility than the first metal.

Abstract: A resin circuit board includes a layered structure of resin layers and conductor layers, has significantly reduced and minimized warping and distortion, and has a precise shape. A second conductor layer is disposed between a resin layer and a first conductor layer made of a metal. The resin layer and the second conductor layer have a higher thermal expansion coefficient than the first conductor layer such that the thermal expansion coefficient changes gradually, allowing a stress resulting from a difference in thermal expansion coefficient to be relieved.

Abstract: A method for manufacturing a component-embedded module includes a first step of preparing a first resin layer made of a thermoplastic resin and including wiring patterns on one of primary surfaces of the first resin layer, a second resin layer made of a thermoplastic resin, and a circuit component including terminal electrodes, and a second step of stacking, heating, and press-bonding the first and second resin layers in a state in which the circuit component is arranged between the one primary surface of the first resin layer and the second resin layer. In the second step, the wiring patterns on the one primary surface of the first resin layer and the terminal electrodes of the circuit component are bonded to each other by solid phase diffusion bonding, to connect the wiring patterns on the one primary surface of the first resin layer and the terminal electrodes of the circuit component to each other.