# US 2018/0322998 A1 · Inductor element

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2018/0322998 A1
- Document ID: US20180322998A1
- Status: Published application
- Kind: A1
- Application number: 15/968,036
- Filed: 2018-05-01
- Published: 2018-11-08
- Earliest claimed: 2017-05-02
- Assignees: TDK Corporation
- Applicants: TDK Corporation
- Inventors: Yasuhide YAMASHITA; Katsushi YASUHARA; Chiomi SATO; Syota GOTO
- Web page: https://patentgrep.com/patent/US20180322998A1

## CPC

- H01F 27/255: made from particles (H01F27/26 takes precedence)
- B29C 43/14: in several steps
- B29C 43/18: incorporating preformed parts or layers, e.g. compression moulding around inserts or for coating articles {(B29C43/206 takes precedence)}
- H01F 17/04: with magnetic core
- H01F 27/02: Casings
- H01F 41/04: for manufacturing coils {(coils for transformer or inductances H01F27/28)}
- B29C 2043/182: {completely}
- B29K 2705/00: Use of metals, their alloys or their compounds, for preformed parts, e.g. for inserts
- B29K 2995/0008: Magnetic or paramagnetic
- B29L 2031/34: Electrical apparatus, e.g. sparking plugs or parts thereof
- H01F 1/36: in the form of particles {(H01F1/346, H01F1/348 and H01F1/38 take precedence)}
- H01F 17/043: {with two, usually identical or nearly identical parts enclosing completely the coil (pot cores)}
- H01F 2017/046: {helical coil made of flat wire, e.g. with smaller extension of wire cross section in the direction of the longitudinal axis}
- H01F 2017/048: {with encapsulating core, e.g. made of resin and magnetic powder}
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## Abstract

An inductor element includes a wire-winding portion and a core portion. In the wire-winding portion, a conductor is wound in a coil shape. The core portion surrounds the wire-winding portion and contains a magnetic powder and a resin. An inner-core central region is a region of the core portion within a distance from a winding axis center of the wire-winding portion toward an existing region of the wire-winding portion in an outward direction perpendicular to the winding axis center. A top-plate central region is a region of the core portion within a distance from the winding axis center toward a no-existing region of the wire-winding portion in the outward direction. Sα−Sβ≥−2% is satisfied, where Sα (%) and sβ (%) are respectively an area ratio of the magnetic powder in the inner-core central region and the top-plate central region.

## Claims

### Claim 1

An inductor element, comprising:
a wire-winding portion where a conductor is wound in a coil shape; and
a core portion surrounding the wire-winding portion and containing a magnetic powder and a resin,
wherein an inner-core central region is defined as a region of the core portion within a predetermined distance from a winding axis center of the wire-winding portion toward an existing region of the wire-winding portion in an outward direction perpendicular to the winding axis center,
wherein a top-plate central region is defined as a region of the core portion within a predetermined distance from the winding axis center toward a no-existing region of the wire-winding portion in the outward direction, and
wherein Sα−Sβ≥−2% is satisfied, where Sα (%) is an area ratio of the magnetic powder in the inner-core central region, and Sβ (%) is an area ratio of the magnetic powder in the top-plate central region, on a cross section of the inductor element passing the winding axis center and parallel thereto.

### Claim 2 (depends on 1)

The inductor element according to claim 1, wherein Sα−Sβ≥−1% is satisfied.

### Claim 3 (depends on 1)

The inductor element according to claim 1, wherein Sα−Sβ≥0% is satisfied.

### Claim 4 (depends on 2)

The inductor element according to claim 2, wherein Sα−Sβ≥0% is satisfied.

### Claim 5 (depends on 1)

The inductor element according to claim 1, wherein Sα≥65% is satisfied.

### Claim 6 (depends on 2)

The inductor element according to claim 2, wherein Sα≥65% is satisfied.

### Claim 7 (depends on 3)

The inductor element according to claim 3, wherein Sα≥65% is satisfied.

### Claim 8 (depends on 4)

The inductor element according to claim 4, wherein Sα≥65% is satisfied.