A three-phase transformer including a transformer housing, a shell-form five-limb transformer core wherein main limbs include two outer main limbs and a middle main limb, three coil arrangements including two outer coil arrangements each arranged around a respective one of the outer main limbs, and a middle coil arrangement arranged around the middle main limb. The outer coil arrangements have an inter-coil insulation configured to electrically insulate the coil arrangements from the transformer housing and from the respective other ones of the coil arrangements, and wherein no inter-coil insulation is provided to the middle coil arrangement.

What is disclosed is a core block, a plurality thereof constituting a laminated core by being connected in an annular shape, the core block including: a plurality of electrical steel sheet pieces stacked to each other; and an adhesion part which is provided between the electrical steel sheet pieces adjacent in a stacking direction and adheres the electrical steel sheet pieces to each other, in which an adhesion area ratio of the electrical steel sheet piece by the adhesion part is 1% or more and 60% or less.

What is disclosed is a core block, a plurality thereof constituting a laminated core by being connected in an annular shape, the core block including: a plurality of electrical steel sheet pieces stacked to each other; and an adhesion part which is provided between the electrical steel sheet pieces adjacent in a stacking direction and adheres the electrical steel sheet pieces to each other, in which an adhesion area ratio of the electrical steel sheet piece by the adhesion part is 1% or more and 60% or less.

An inductor includes a first magnetic body having a toroidal shape and having a ferrite; and a second magnetic body configured to be different from the first magnetic body and including a metal ribbon, wherein the second magnetic body includes an outer magnetic body disposed on an outer circumferential surface of the first magnetic body and an inner magnetic body disposed on an inner circumferential surface of the first magnetic body, and each of the outer magnetic body and inner magnetic body is wound in a plurality of layers in a circumferential direction of the first magnetic body.

An inductor includes a first magnetic body having a toroidal shape and having a ferrite; and a second magnetic body configured to be different from the first magnetic body and including a metal ribbon, wherein the second magnetic body includes an outer magnetic body disposed on an outer circumferential surface of the first magnetic body and an inner magnetic body disposed on an inner circumferential surface of the first magnetic body, and each of the outer magnetic body and inner magnetic body is wound in a plurality of layers in a circumferential direction of the first magnetic body.

Provided is a wound core formed by laminating a plurality of bent bodies obtained by forming a coated grain-oriented electrical steel sheet in which a coating is formed on at least one surface of a grain-oriented electrical steel sheet so that the coating is on an outside, in a sheet thickness direction, in which the bent body has a bent region obtained by bending the coated grain-oriented electrical steel sheet and a flat region adjacent to the bent region, the number of deformation twins present in the bent region in a side view is five or less per 1 mm of a length of a center line in the sheet thickness direction in the bent region, and when a region extending 40 times a sheet thickness to both sides in a circumferential direction from a center of the bent region on an outer circumferential surface of the bent body is defined as a strain affected region, a proportion of an area where the coating is not damaged at any position along the circumferential direction in a flat region within the strain affected region is 90% or more.

Provided is a wound core formed by laminating a plurality of bent bodies obtained by forming a coated grain-oriented electrical steel sheet in which a coating is formed on at least one surface of a grain-oriented electrical steel sheet so that the coating is on an outside, in a sheet thickness direction, in which the bent body has a bent region obtained by bending the coated grain-oriented electrical steel sheet and a flat region adjacent to the bent region, the number of deformation twins present in the bent region in a side view is five or less per 1 mm of a length of a center line in the sheet thickness direction in the bent region, and when a region extending 40 times a sheet thickness to both sides in a circumferential direction from a center of the bent region on an outer circumferential surface of the bent body is defined as a strain affected region, a proportion of an area where the coating is not damaged at any position along the circumferential direction in a flat region within the strain affected region is 90% or more.

Embodiments of the invention are directed to a method of fabricating a yoke arrangement of an inductor. A non-limiting example method includes forming a dielectric layer across from a major surface of a substrate. The method further includes configuring the dielectric layer such that it imparts a predetermined dielectric layer compressive stress on the substrate. A magnetic stack is formed on an opposite side of the dielectric layer from the substrate, wherein the magnetic stack includes one or more magnetic layers alternating with one or more insulating layers. The method further includes configuring the magnetic stack such that it imparts a predetermined magnetic stack tensile stress on the dielectric layer, wherein a net effect of the predetermined dielectric layer compressive stress and the predetermined magnetic stack tensile stress on the substrate is insufficient to cause a portion of the major surface of the substrate to be substantially non-planar.

Embodiments of the invention are directed to a method of fabricating a yoke arrangement of an inductor. A non-limiting example method includes forming a dielectric layer across from a major surface of a substrate. The method further includes configuring the dielectric layer such that it imparts a predetermined dielectric layer compressive stress on the substrate. A magnetic stack is formed on an opposite side of the dielectric layer from the substrate, wherein the magnetic stack includes one or more magnetic layers alternating with one or more insulating layers. The method further includes configuring the magnetic stack such that it imparts a predetermined magnetic stack tensile stress on the dielectric layer, wherein a net effect of the predetermined dielectric layer compressive stress and the predetermined magnetic stack tensile stress on the substrate is insufficient to cause a portion of the major surface of the substrate to be substantially non-planar.

Disclosed herein is an antenna device that includes a substrate; a conductor pattern formed on the substrate and including a spiral or loop-shaped antenna coil, a spiral or loop-shaped coupling coil being connected to the antenna coil and having a diameter smaller than that of the antenna coil, and a spiral-shaped booster coil at least partially overlapping the antenna coil through the substrate without being connected thereto; and a resonance capacitor connected to the booster coil. The number of turns of the booster coil is larger than that of the antenna coil.