# US 2019/0172630 A1 · Coil device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0172630 A1 - Document ID: US20190172630A1 - Status: Published application - Kind: A1 - Application number: 16/190,819 - Filed: 2018-11-14 - Published: 2019-06-06 - Earliest claimed: 2017-11-16 - Assignees: TDK Corporation - Applicants: TDK Corporation - Inventors: Yugo ASAI; Tsutomu KOBAYASHI; Daisuke URABE; Hiroshi SUZUKI - Web page: https://patentgrep.com/patent/US20190172630A1 ## CPC - H01F 27/29: Terminals; Tapping arrangements {for signal inductances} - H01F 17/04: with magnetic core - H01F 17/045: {with core of cylindric geometry and coil wound along its longitudinal axis, i.e. rod or drum core} - H01F 27/2823: {Wires (H01F27/2866 takes precedence)} - H01F 27/2828: {Construction of conductive connections, of leads} - H01F 27/292: {Surface mounted devices} - H01F 27/38: Auxiliary core members; Auxiliary coils or windings - H01F 38/48: {Common mode inductor for reducing or eliminating common mode noise on parallel lines} - H01F 2003/106: {Magnetic circuits using combinations of different magnetic materials} - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES ## Abstract A coil device having excellent mode conversion property which can be suitably used as a common mode filter. The coil device has a core, a first collar part and a second collar part provided to both sides of the core in axis direction, a coil part at least having a first wire and a second wire which are wound around the core, and terminals provided to the collar parts. One lead part of the wire heading towards the coil part from the terminals, and one lead part of the wire heading towards the coil part from the second terminal are placed in close proximity at least between an inner face of the collar part and the coil part. ## Claims ### Claim 1 A coil device comprising a core, a first collar part and a second collar part each provided at both sides along the axis direction of the core, a coil part at least having a first wire and a second wire which are wound around the core, a first terminal connected with one lead part of the first wire and provided to the first collar part, a second terminal connected with one lead part of the second wire and provided apart from the first terminal to the first collar part, a third terminal connected with other lead part of the first wire and provided to the second collar part, a fourth terminal connected with other lead part of the second wire and provided apart from the third terminal to the second collar part, wherein the one lead part of the first wire heading towards the coil part from the first terminal and the one lead part of the second wire heading towards the coil part from the second terminal are placed in close proximity at least between the coil part and an inner face of the first collar part, and the first wire and the second wire form a crossing part of which the first wire and the second wire are crossing against each other in the middle of the core. ### Claim 2 (depends on 1) The coil device according to claim 1, wherein the other lead part of the first wire heading towards the coil part from the third terminal and the other lead part of the second wire heading towards the coil part from the second terminal are placed in an close proximity at least between the coil part and the second collar part. ### Claim 3 (depends on 1) The coil device according to claim 1, wherein the first collar part is provided with a first common guiding passage which guides the one lead part of the first wire and the one lead part of the second wire together towards outside from the inner face of the first collar part. ### Claim 4 (depends on 2) The coil device according to claim 2, wherein the second collar part is provided with the second common guiding passage which guides the other lead part of the first wire and the other lead part of the second wire together towards outside from the inner face of the second collar part. ### Claim 5 (depends on 1) The coil device according to claim 1, wherein the first collar part is provided with a first terminal guiding passage which guides the one lead part of the first wire towards outside from the inner face of the first collar part and a second terminal guiding passage which guides the one lead part of the second wire towards outside from the inner face of the first collar part, and the first terminal guiding passage and the second terminal guiding passage are in close proximity at the inner face of the first collar part. ### Claim 6 (depends on 1) The coil device according to claim 1, wherein the second collar part is provided with a third terminal guiding passage which guides the other lead part of the first wire towards outside from the inner face of the second collar part and a fourth terminal guiding passage which guides the other lead part of the second wire towards outside from the inner face of the second collar part, and the third terminal guiding passage and the fourth terminal guiding passage are in close proximity at the inner face of the second collar part. ### Claim 7 (depends on 1) The coil device according to claim 1 further comprising a flat board extending between an opposite face of a mounting face of the first collar part and an opposite face of a mounting face of the second collar part. ### Claim 8 (depends on 7) The coil device according to claim 7, wherein the flat board is provided with a flat board first common guiding passage which guides the one lead part of the first wire and the one lead part of the second wire together towards outside from the inner face of the first collar part. ### Claim 9 (depends on 7) The coil device according to claim 7, wherein the flat board is provided with a flat board second common guiding passage which guides the other lead part of the first wire and the other lead part of the second wire towards outside from the inner face of the second collar part. ### Claim 10 (depends on 1) The coil device according to claim 1, wherein a wire length of the one lead part of the first wire from the coil part to the first terminal is approximately same as a wire length of the one lead part of the second wire from the coil part to the second terminal. ### Claim 11 (depends on 1) The coil device according to claim 1, wherein a number of winding of the first wire of the coil part is same as a number of winding of the second wire of the coil part. ### Claim 12 (depends on 1) The coil device according to claim 1, wherein a winding density of the first wire and a winding density of the second wire decrease in the middle of the core and forms an exposed area of the core in which a surface of the core is exposed, and the crossing part is form at the exposed area. ### Claim 13 (depends on 1) The coil device according to claim 1, wherein wire connecting parts of the first terminal, the second terminal, the third terminal, and the fourth terminal are positioned other than the mounting face of the first collar part and the second collar part.