Disclosed herein is a coil component that includes: a drum-shaped core including a first flange part, a second flange part, and a winding core part positioned between the first and second flange parts; a plurality of first terminal electrodes provided on the first flange part; a plurality of second terminal electrodes provided on the second flange part; and a plurality of wires wound around the winding core part, each of the plurality of wires having a first end connected to an associated one of the first terminal electrodes, and having a second end connected to an associated one of the second terminal electrodes. Each of the first and second flange parts has a tapered groove whose side surfaces are inclined. The plurality of wires are accommodated in the tapered grooves.

A coil device includes a winding core, a wire, and a terminal fitting. The winding core is made of a magnetic material and includes a flange. The wire is wound around the winding core. The terminal fitting is attached to a part of an outer surface of the flange. The terminal fitting includes a contact part and a protrusion plate part. The contact part is contacted with the outer surface of the flange. The protrusion plate part is formed integrally with the contact part and protrudes away from the flange. The protrusion plate part includes a wire connection surface and a main mounting surface. A lead end of the wire is connected to the wire connection surface. The main mounting surface is located opposite to the wire connection surface and is connectable to an external circuit.

A coil device includes a winding core, a wire, and a terminal fitting. The winding core is made of a magnetic material and includes a flange. The wire is wound around the winding core. The terminal fitting is attached to a part of an outer surface of the flange. The terminal fitting includes a contact part and a protrusion plate part. The contact part is contacted with the outer surface of the flange. The protrusion plate part is formed integrally with the contact part and protrudes away from the flange. The protrusion plate part includes a wire connection surface and a main mounting surface. A lead end of the wire is connected to the wire connection surface. The main mounting surface is located opposite to the wire connection surface and is connectable to an external circuit.

A coil component includes a drum core including a winding core portion and flange portions on opposite sides of the winding core portion in its axial direction, a wire wound around the winding core portion, and a sheet core arranged on a top surface of each of the flange portions and on the wire with an adhesive interposed therebetween. The adhesive contains no filler. A shortest distance between the top surface of the flange portion and the sheet core is not smaller than about 3 μm.

A coil component includes a drum core including a winding core portion and flange portions on opposite sides of the winding core portion in its axial direction, a wire wound around the winding core portion, and a sheet core arranged on a top surface of each of the flange portions and on the wire with an adhesive interposed therebetween. The adhesive contains no filler. A shortest distance between the top surface of the flange portion and the sheet core is not smaller than about 3 μm.

A balun includes a core having a plurality of through holes and a plurality of conductors wound around a portion between two through holes in the core and constituting first and second coils. The conductors include parallel lines in which a first conductor, a second conductor, and a third conductor are arranged in substantially parallel in this order and are integrated so as to include planar sections. The first and second coils include a continuous portion of first, second, and third winding portions. The first winding portion is formed of the wound second conductor. The second winding portion is formed of the parallel lines wound such that the planar sections cover the first winding portion. The third winding portion is formed of the second conductor wound on the second winding portion. The first coil includes a center tap connected to end portions of the first and third conductors.

A balun includes a core having a plurality of through holes and a plurality of conductors wound around a portion between two through holes in the core and constituting first and second coils. The conductors include parallel lines in which a first conductor, a second conductor, and a third conductor are arranged in substantially parallel in this order and are integrated so as to include planar sections. The first and second coils include a continuous portion of first, second, and third winding portions. The first winding portion is formed of the wound second conductor. The second winding portion is formed of the parallel lines wound such that the planar sections cover the first winding portion. The third winding portion is formed of the second conductor wound on the second winding portion. The first coil includes a center tap connected to end portions of the first and third conductors.

A method for preparing a metallic magnetic powder core integrated chip inductor is provided, comprising steps of: winding a hollow spiral coil, compression molding, primary chamfering, hot pressing curing, secondary chamfering, primary nano-insulation coating, primary grinding, electrode copper plating, secondary nano-insulation coating, secondary grinding, electroplating metalized electrode, and testing packaging. The metallic magnetic powder core integrated chip inductor of the present invention adopts nano-insulating material to cover the product body and only retains the bottom electrode for connection, which eliminates tin stacking side area comparing to the paste terminated electroplating type and the material spot welding electrode type integrated chip inductor product, and thus reduce the installation volume of the product on the circuit board, increase the installation density of electronic components on the PCB board.

A coil having a coil body and a plurality of concentric cross-section windings of wire disposed around the coil body, the wire having a spacing between adjacent turns of about 0.25 to 1.0 of the radius of the wire. Also, a coil for a plasma processing device, the coil having a coil body and a plurality of concentric cylindrical cross-section windings of wire disposed around the coil body, the wire having a spacing between adjacent turns of about 0.25 to 1.0 of the radius of the wire and a diameter to length ratio of between about 2:1 and about 3:1.

A coil having a coil body and a plurality of concentric cross-section windings of wire disposed around the coil body, the wire having a spacing between adjacent turns of about 0.25 to 1.0 of the radius of the wire. Also, a coil for a plasma processing device, the coil having a coil body and a plurality of concentric cylindrical cross-section windings of wire disposed around the coil body, the wire having a spacing between adjacent turns of about 0.25 to 1.0 of the radius of the wire and a diameter to length ratio of between about 2:1 and about 3:1.