SMALL ELECTRONIC COMPONENT, ELECTRONIC CIRCUIT BOARD, AND METHOD OF MANUFACTURING SMALL ELECTRONIC COMPONENT

• US 20170034915A1
• Filed: 07/13/2016
• Published: 02/02/2017
• Est. Priority Date: 07/29/2015
• Status: Active Grant

• Current Assignee: Sumida Corporation
• Original Assignee: Sumida Corporation
• Inventors: UCHIKOBA, Fumio, OTSUKA, Tsutomu, KAWARAI, Mitsugu, TAKAHASHI, Motomi
• Granted Patent: US 10,617,006 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01F 1/26 by macromolecular organic substances
• CPC Class Codes: H01F 27/02 Casings
• CPC Class Codes: H01F 27/022 Encapsulation
• CPC Class Codes: H01F 27/24 Magnetic cores
• CPC Class Codes: H01F 27/255 made from particles H01F27/26 takes precedence
• CPC Class Codes: H01F 27/28 Coils; Windings; Conductive connections
• CPC Class Codes: H01F 27/30 Fastening or clamping coils, windings, or parts thereof together; Fastening or mounting coils or windings on core, casing, or other support
• CPC Class Codes: H01F 41/0206 Manufacturing of magnetic cores by mechanical means magnetic cores per se H01F27/24
• CPC Class Codes: H01F 41/0246 Manufacturing of magnetic circuits by moulding or by pressing powder magnetic cores made by moulding or by pressing powder H01F27/255; soft magnetic particles H01F1/20, H01F1/36
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 2201/1003 Non-printed inductor

Abstract

Provided are a small electronic component including: a magnetic core including at least a columnar core part; a winding coil arranged so as to surround an outer peripheral surface side of the columnar core part and formed by winding a winding wire; and a magnetic cover part formed so as to cover at least part of the magnetic core and the winding coil while following at least part of shapes of the magnetic core and the winding coil through use of a magnetic material containing a mixture of a phosphoric acid ester-based surfactant, magnetic powder, and a resin, an electronic circuit board using the small electronic component, and a method of manufacturing a small electronic component.

Claims

1. A small electronic component, comprising:

a magnetic core comprising at least a columnar core part;

a winding coil arranged so as to surround an outer peripheral surface side of the columnar core part and formed by winding a winding wire; and

a magnetic cover part formed so as to cover at least part of the magnetic core and the winding coil while following at least part of shapes of the magnetic core and the winding coil through use of a magnetic material containing a mixture of a phosphoric acid ester-based surfactant, magnetic powder, and a resin.

2. A small electronic component according to claim 1, wherein the magnetic cover part has a minimum thickness of 0.8 mm or less.

3. A small electronic component according to claim 1, wherein the magnetic cover part has a minimum thickness of 0.5 mm or less.

4. A small electronic component according to claim 1, wherein a surface of the magnetic cover part has a surface roughness Ra of 6.3 μ

m or less.

5. A small electronic component according to claim 1, wherein a surface of the magnetic cover part has a surface roughness Ra of 1.6 μ

m or less.

6. A small electronic component according to claim 1, wherein the magnetic cover part is molded so as to cover the entire winding coil and part of the magnetic core including the columnar core part while following a shape of the entire winding coil and a shape of part of the magnetic core.

7. A small electronic component according to claim 1, wherein the magnetic core comprises the columnar core part and a flange part extending in a direction orthogonal to an axial direction of the columnar core part.

8. An electronic circuit board, comprising at least a wiring board having wiring patterned thereon and a small electronic component,

wherein the small electronic component comprises:

a magnetic core comprising at least a columnar core part;

a winding coil arranged so as to surround an outer peripheral surface side of the columnar core part and formed by winding a winding wire; and

a magnetic cover part formed so as to cover at least part of the magnetic core and the winding coil while following at least part of shapes of the magnetic core and the winding coil through use of a magnetic material containing a mixture of a phosphoric acid ester-based surfactant, magnetic powder, and a resin.

9. An electronic circuit board according to claim 8, wherein the wiring further has another electronic component connected thereto.

10. A method of manufacturing a small electronic component, the method at least comprising:

arranging a member to be covered in a space formed in a mold, the member to be covered including a magnetic core that includes at least a columnar core part and a winding coil which is arranged so as to surround an outer peripheral surface side of the columnar core part and is formed by winding a winding wire; and

filling an uncured magnetic material containing a mixture of a phosphoric acid ester-based surfactant, magnetic powder, and a resin into the space, to thereby mold a shape of the magnetic material covering the member to be covered,

wherein the small electronic component comprises;

the magnetic core;

the winding coil; and

a magnetic cover part formed so as to cover at least part of the magnetic core and the winding coil while following at least part of shapes of the magnetic core and the winding coil through use of the magnetic material.

11. A method of manufacturing the small electronic component according to claim 10, wherein, in the molding, a minimum clearance between an inner wall surface of the mold and the member to be covered is 0.8 mm or less.