Abstract: Provided is a resin composition for optical waveguide cores, the resin composition including liquid epoxy resin, and solid epoxy resin, in which a coefficient of variation calculated from a weighted average value of a refractive index of the liquid epoxy resin and a refractive index of the solid epoxy resin is 2.10% or less.

Abstract: An optical waveguide is provided and includes: a core forming layer with a high refractive index; and a first clad layer with a low refractive index, bonded to a first main surface of the core forming layer. The core forming layer is provided in its plane direction with a core portion, lateral clad portions each having one side adjacent to a corresponding side of the core portion, and high refractive index portions each adjacent to the other side of a corresponding one of the lateral clad portions. The core portion is provided in its plane direction with a central region, and GI regions in each of which a refractive index continuously decreases from the central region toward an interface with the corresponding one of the lateral clad portions. The lateral clad portions each include a region having a constant refractive index.

Abstract: An optical-waveguide-clad composition includes a bisphenol type epoxy compound (A), and an epoxy compound (B) containing, in a molecule, at least one of a structure represented by the following formula (1) and a structure represented by the following formula (2), and having a molecular weight of 350 or higher. In the formula (1), R1 and R2 each independently represent a hydrogen atom or an alkyl group, and m represents 2 to 15. In the formula (2), R3 and R4 each independently represent a hydrogen atom or an alkyl group, and n represents 2 to 15.

Abstract: Provided is a resin composition for optical waveguide cores, the resin composition including liquid epoxy resin, and solid epoxy resin, in which a coefficient of variation calculated from a weighted average value of a refractive index of the liquid epoxy resin and a refractive index of the solid epoxy resin is 2.10% or less.

Abstract: An optical waveguide provided and includes: a core forming layer with a high refractive index; and a first clad layer with a low refractive index, bonded to a first main surface of the core forming layer. The core forming layer is provided in its plane direction with a core portion, lateral clad portions each having one side adjacent to a corresponding side of the core portion, and high refractive index portions each adjacent to the other side of a corresponding one of the lateral clad portions. The core portion is provided in its plane direction with a central region, and GI regions in each of which a refractive index continuously decreases from the central region toward an interface with the corresponding one of the lateral clad portions. The lateral clad portions each include a region having a constant refractive index.

Abstract: A composition for an optical waveguide is cured into a sheet to give a cured product. A difference in light transmittance with respect to light having a wavelength of 450 nm is 15% or less between this cured product and this cured product after retention in atmosphere at 175° C. for 40 hours, the light transmittance being calculated in terms of the cured product at a thickness of 50 ?m.

Abstract: A composition for an optical waveguide is cured into a sheet to give a cured product. A difference in light transmittance with respect to light having a wavelength of 450 nm is 15% or less between this cured product and this cured product after retention in atmosphere at 175° C. for 40 hours, the light transmittance being calculated in terms of the cured product at a thickness of 50 ?m.

Abstract: A composition for an optical waveguide is cured into a sheet to give a cured product. A difference in light transmittance with respect to light having a wavelength of 450 nm is 15% or less between this cured product and this cured product after retention in atmosphere at 175° C. for 40 hours, the light transmittance being calculated in terms of the cured product at a thickness of 50 ?m.

Abstract: A composition for an optical waveguide is cured into a sheet to give a cured product. A difference in light transmittance with respect to light having a wavelength of 450 nm is 15% or less between this cured product and this cured product after retention in atmosphere at 175° C. for 40 hours, the light transmittance being calculated in terms of the cured product at a thickness of 50 ?m.

Abstract: The present invention relates to a dry film for optical waveguides, obtained through sequential stacking of a carrier film, a plating adhesion layer, an uncured cladding layer and a cover film. Solid microparticles are dispersed in a resin composition that constitutes the plating adhesion layer.

Abstract: The present invention relates to a dry film for an optical waveguide which has a carrier base material, a resin layer for an optical waveguide that can be cured by active energy ray or heat, and a protective film. The surface of the protective film that is in contact with the resin layer for an optical waveguide is a roughened surface.

Abstract: The present invention provides an optical waveguide excellent in all of transparency, a bending property and heat resistance and a dry film for manufacturing an optical waveguide. A clad layer of the optical waveguide according to the present invention is formed by using a dry film containing a polymer comprising at least a (meth)acrylate monomer with an epoxy group and a (meth)acrylate monomer without an epoxy group; and cationic or anionic curing initiator.

Abstract: The present invention relates to a dry film for optical waveguides, obtained through sequential stacking of a carrier film, a plating adhesion layer, an uncured cladding layer and a cover film. Solid microparticles are dispersed in a resin composition that constitutes the plating adhesion layer.

Abstract: The present invention relates to a dry film for an optical waveguide which has a carrier base material, a resin layer for an optical waveguide that can be cured by active energy ray or heat, and a protective film. The surface of the protective film that is in contact with the resin layer for an optical waveguide is a roughened surface.

Abstract: An optical-electrical composite flexible circuit substrate having sufficiently high bending resistance is provided. An optical-electrical composite flexible circuit substrate includes: an optical circuit that includes a core portion and a cladding layer that covers the core portion; and an electrical circuit, with the optical circuit and the electrical circuit being disposed at a position that includes a neutral surface when the optical-electrical composite flexible circuit substrate is bent, or at a position near the neutral surface. Alternatively, the optical-electrical composite flexible circuit substrate may include an optical circuit that includes a core portion and a cladding layer that covers the core portion; and a substrate that includes an electrical circuit, with the substrate and the optical circuit being laminated so that the electrical circuit is disposed on a side closer to the optical circuit.

Abstract: The present invention provides an optical waveguide excellent in all of transparency, a bending property and heat resistance and a dry film for manufacturing an optical waveguide. A clad layer of the optical waveguide according to the present invention is formed by using a dry film containing a polymer comprising at least a (meth)acrylate monomer with an epoxy group and a (meth)acrylate monomer without an epoxy group; and cationic or anionic curing initiator.

Abstract: An optical-electrical composite flexible circuit substrate having sufficiently high bending resistance is provided. An optical-electrical composite flexible circuit substrate includes: an optical circuit that includes a core portion and a cladding layer that covers the core portion; and an electrical circuit, with the optical circuit and the electrical circuit being disposed at a position that includes a neutral surface when the optical-electrical composite flexible circuit substrate is bent, or at a position near the neutral surface. Alternatively, the optical-electrical composite flexible circuit substrate may include an optical circuit that includes a core portion and a cladding layer that covers the core portion; and a substrate that includes an electrical circuit, with the substrate and the optical circuit being laminated so that the electrical circuit is disposed on a side closer to the optical circuit.

Abstract: There are provided a laminate with an inside layer circuit for use as a multilayer printed circuit board, a method for measuring a circuit impedance of the laminate, and a measuring device that enables a nondestructive impedance measurement accurately. The laminate with the inside layer circuit has a dielectric substrate, a first conductive layer disposed on an upper surface of the dielectric substrate to form a high frequency circuit, a second conductive layer disposed on a lower surface of the dielectric substrate, and a third conductive layer disposed over a first dielectric layer on the upper surface of the dielectric substrate. A test conductor is formed independently of the inside layer circuit within the first conductive layer.