Abstract: A method for manufacturing a multilayer coil includes preparing a first substrate by forming a first conductor pattern on a first insulating base material layer, preparing a second substrate by forming a second conductor pattern on a second insulating base material layer, and joining a surface of the first substrate on which the first conductor pattern is formed and a surface of the second substrate on which the second conductor pattern is formed together with only a joining layer made of a thermoplastic resin interposed therebetween. Amounts of deformation of the first and second insulating base material layers are less than that of the joining layer at a fusion temperature. The first and second conductor patterns are each a coil pattern having a coil axis that extends in a lamination direction in which the first substrate and the second substrate are laminated together.

Abstract: A signal transmission line includes a laminate, a signal conductor, a hollow portion, and a reinforcing conductor. The laminate includes a flexible laminate including resin layers each of which has flexibility. The signal conductor extends in a signal transmission direction of the laminate and is disposed in an intermediate position in a laminating direction of the resin layers. The hollow portion is in the laminate and defined by an opening provided at a portion of the plurality of resin layers. The reinforcing conductor is in the laminate. The hollow portion is disposed at a position overlapping with the signal conductor, in a plan view of the laminate from a surface perpendicular or substantially perpendicular to the laminating direction. The reinforcing conductor is disposed at a position different from the position of the hollow portion in a plan view.

Abstract: A signal transmission line includes first and second base materials, and conductive bonding materials. The first base material includes a signal conductor. The second base material includes a ground conductor. The conductive bonding materials bond the first base and second base material to provide a gap. The first base material includes a mounting conductor to which the conductive bonding materials are respectively bonded. The mounting conductor includes a portion extending in parallel or substantially in parallel with the signal conductor on a side of a first side surface, and a portion extending in parallel or substantially in parallel with the signal conductor on a side of a second side surface. A position of a portion of the mounting conductor on the side of the first side surface and a position of a portion of the mounting conductor on the side of the second side surface are different from each other in a signal transmission direction.

Abstract: A signal transmission line includes a signal region that includes a signal conductor layer and insulating base material layers, and a first ground region that includes a first ground conductor layer and insulating base material layers and is located above the signal region. The signal region is not fixed to the first ground region in a first section of a base. One or more first spacers are fixed to the signal region and in contact with the first ground region without being fixed thereto, or are in contact with the signal region without being fixed thereto and fixed to the first ground region. The one or more first spacers are in the first section.

Abstract: A method of manufacturing a multilayer board includes forming conductor patterns on four or more insulating base material layers, forming a multilayer body by stacking the insulating base material layers in a state in which the conductor patterns face each other with prepreg layers therebetween, and heat-pressing the multilayer body. In a state before the step of heat-pressing, among the prepreg layers, a thickness of an outermost prepreg layer is larger than a thickness of a prepreg layer other than the outermost prepreg layer.

Abstract: A multilayer board includes a first substrate made of a thermoplastic resin, a first conductor pattern provided on the first substrate, a second substrate made of the thermoplastic resin, and a second conductor pattern provided on the second substrate. An insulation coating which covers the first conductor pattern is partially disposed between the first substrate and the second substrate. The insulation coating is made of a material having lower fluidity at a predetermined press temperature than fluidities of the first substrate and the second substrate, and a plurality of substrates including the first substrate and the second substrate are laminated and thermally compressed and bonded at the press temperature.

Abstract: A black liquid-crystal polymer film that contains a black pigment and a liquid crystal polymer and the black liquid-crystal polymer film has a lightness of 45 or less, a dielectric loss tangent of 0.0035 or less, a minimum dielectric breakdown strength of 60 kV/mm or more, and a maximum-to-minimum ratio of in-plane thermal linear expansion coefficient in the range of 1.0 to 2.5.

Abstract: A signal transmission line includes a laminate, a signal conductor, a hollow portion, and a reinforcing conductor. The laminate includes a flexible laminate including resin layers each of which has flexibility. The signal conductor extends in a signal transmission direction of the laminate and is disposed in an intermediate position in a laminating direction of the resin layers. The hollow portion is in the laminate and defined by an opening provided at a portion of the plurality of resin layers. The reinforcing conductor is in the laminate. The hollow portion is disposed at a position overlapping with the signal conductor, in a plan view of the laminate from a surface perpendicular or substantially perpendicular to the laminating direction. The reinforcing conductor is disposed at a position different from the position of the hollow portion in a plan view.

Abstract: A signal transmission line includes a laminate, a signal conductor, a hollow portion, and a reinforcing conductor. The laminate includes a flexible laminate including resin layers each of which has flexibility. The signal conductor extends in a signal transmission direction of the laminate and is disposed in an intermediate position in a laminating direction of the resin layers. The hollow portion is in the laminate and defined by an opening provided at a portion of the plurality of resin layers. The reinforcing conductor is in the laminate. The hollow portion is disposed at a position overlapping with the signal conductor, in a plan view of the laminate from a surface perpendicular or substantially perpendicular to the laminating direction. The reinforcing conductor is disposed at a position different from the position of the hollow portion in a plan view.

Abstract: An interposer includes a stacked body including insulating base material layers that are stacked on one another, first and second electrodes, a conductor pattern, and an interlayer connection conductor. The stacked body includes a first mounting surface including a first electrode, and a second mounting surface facing the first mounting surface and including a second electrode. The first electrode is electrically connected to the second electrode through the conductor pattern and the interlayer connection conductor. A length of an electrical path including conductor patterns connecting the first electrode and the second electrode is larger than a total length of the interlayer connection conductor in a stacking direction.

Abstract: An interposer includes a stacked body including first and second mounting surfaces that face each other, a first electrode on the first mounting surface, and a second electrode on the second mounting surface. The stacked body includes flexible insulating layers stacked on each other, and a folded portion. The first and second electrodes are electrically connected to each other. The stacked body includes an upright portion between the first and second mounting surfaces and in which a stacking direction in which the insulating layers are stacked is parallel to the first and second mounting surfaces, and a bent portion bent in a plan view of the first and second mounting surfaces.

Abstract: An interposer includes a stacked body including insulating base material layers that are stacked on one another, first and second electrodes, a conductor pattern, and an interlayer connection conductor. The stacked body includes a first mounting surface including a first electrode, and a second mounting surface facing the first mounting surface and including a second electrode. The first electrode is electrically connected to the second electrode through the conductor pattern and the interlayer connection conductor. A length of an electrical path including conductor patterns connecting the first electrode and the second electrode is larger than a total length of the interlayer connection conductor in a stacking direction.

Abstract: A signal transmission line includes a laminate, a signal conductor, a hollow portion, and a reinforcing conductor. The laminate includes a flexible laminate including resin layers each of which has flexibility. The signal conductor extends in a signal transmission direction of the laminate and is disposed in an intermediate position in a laminating direction of the resin layers. The hollow portion is in the laminate and defined by an opening provided at a portion of the plurality of resin layers. The reinforcing conductor is in the laminate. The hollow portion is disposed at a position overlapping with the signal conductor, in a plan view of the laminate from a surface perpendicular or substantially perpendicular to the laminating direction. The reinforcing conductor is disposed at a position different from the position of the hollow portion in a plan view.

Abstract: An interposer includes a stacked body including first and second mounting surfaces that face each other, a first electrode on the first mounting surface, and a second electrode on the second mounting surface. The stacked body includes flexible insulating layers stacked on each other, and a folded portion. The first and second electrodes are electrically connected to each other. The stacked body includes an upright portion between the first and second mounting surfaces and in which a stacking direction in which the insulating layers are stacked is parallel to the first and second mounting surfaces, and a bent portion bent in a plan view of the first and second mounting surfaces.

Abstract: A signal transmission line includes a laminate, a signal conductor, a hollow portion, and a reinforcing conductor. The laminate includes a flexible laminate including resin layers each of which has flexibility. The signal conductor extends in a signal transmission direction of the laminate and is disposed in an intermediate position in a laminating direction of the resin layers. The hollow portion is in the laminate and defined by an opening provided at a portion of the plurality of resin layers. The reinforcing conductor is in the laminate. The hollow portion is disposed at a position overlapping with the signal conductor, in a plan view of the laminate from a surface perpendicular or substantially perpendicular to the laminating direction. The reinforcing conductor is disposed at a position different from the position of the hollow portion in a plan view.

Abstract: An electronic device includes a transmission line and a circuit board. The transmission line includes a signal conductor, a base material, a first external connection conductor, a second external connection conductor, and a ground conductor, and defines a stripline. The circuit board includes a first mounting land conductor, a second mounting land conductor, and a radiation reduction conductor. The first mounting land conductor and the second mounting land conductor are provided in a concave portion on the surface of the circuit board, and are respectively connected to the first external connection conductor and the second external connection conductor. The radiation reduction conductor is provided on the lateral surface of the concave portion in which the transmission line is disposed, and is in contact with or adjacent to the first lateral surface and the second lateral surface of the base material.

Abstract: A black liquid-crystal polymer film that contains a black pigment and a liquid crystal polymer and the black liquid-crystal polymer film has a lightness of 45 or less, a dielectric loss tangent of 0.0035 or less, a minimum dielectric breakdown strength of 60 kV/mm or more, and a maximum-to-minimum ratio of in-plane thermal linear expansion coefficient in the range of 1.0 to 2.5.

Abstract: A multilayer board includes a first substrate made of a thermoplastic resin, a first conductor pattern provided on the first substrate, a second substrate made of the thermoplastic resin, and a second conductor pattern provided on the second substrate. An insulation coating which covers the first conductor pattern is partially disposed between the first substrate and the second substrate. The insulation coating is made of a material having lower fluidity at a predetermined press temperature than fluidities of the first substrate and the second substrate, and a plurality of substrates including the first substrate and the second substrate are laminated and thermally compressed and bonded at the press temperature.

Abstract: A method of manufacturing a multilayer board includes forming conductor patterns on four or more insulating base material layers, forming a multilayer body by stacking the insulating base material layers in a state in which the conductor patterns face each other with prepreg layers therebetween, and heat-pressing the multilayer body. In a state before the step of heat-pressing, among the prepreg layers, a thickness of an outermost prepreg layer is larger than a thickness of a prepreg layer other than the outermost prepreg layer.

Abstract: A method for manufacturing a multilayer coil includes preparing a first substrate by forming a first conductor pattern on a first insulating base material layer, preparing a second substrate by forming a second conductor pattern on a second insulating base material layer, and joining a surface of the first substrate on which the first conductor pattern is formed and a surface of the second substrate on which the second conductor pattern is formed together with only a joining layer made of a thermoplastic resin interposed therebetween. Amounts of deformation of the first and second insulating base material layers are less than that of the joining layer at a fusion temperature. The first and second conductor patterns are each a coil pattern having a coil axis that extends in a lamination direction in which the first substrate and the second substrate are laminated together.