Composite magnetic body, and magnetic element and method of manufacturing the same

• US 6,661,328 B2
• Filed: 07/17/2002
• Issued: 12/09/2003
• Est. Priority Date: 04/28/2000
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Fujii, Hiroshi, Takahashi, Takeshi, Inoue, Osamu, Matsutani, Nobuya, Kato, Junichi
• Primary Examiner(s): Nguyen, Tuyen
• Application Number:
  US10/198,500
• Publication Number:
  US 20030001718A1
• Time in Patent Office: 510 Days
• Field of Search: 336/65, 336/83, 336/200, 336/232, 336/233, 296/021, 296/031, 296/05, 298/48, 298/56, 298/58, 298/83, 298/880.47, 298/880.72, 298/980.49
• US Class Current: 336/233
• CPC Class Codes: H01F 1/24 the particles being insulated
• CPC Class Codes: H01F 1/26 by macromolecular organic substances
• CPC Class Codes: H01F 1/28 dispersed or suspended in a bonding agent
• CPC Class Codes: H01F 17/04 with magnetic core
• CPC Class Codes: H01F 27/027 specially adapted for combination of signal type inductors or transformers with electronic circuits, e.g. mounting on printed circuit boards
• CPC Class Codes: H01F 27/292 Surface mounted devices
• 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: H01F 41/127 Encapsulating or impregnating encapsulating coil and core H01F41/005
• CPC Class Codes: Y10S 156/922 Specified electronic component delaminating in preparation for recycling
• CPC Class Codes: Y10T 156/1082 Partial cutting bonded sandwich [e.g., grooving or incising]
• CPC Class Codes: Y10T 156/11 Methods of delaminating, per se; i.e. , separating at bonding face
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49021 Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
• CPC Class Codes: Y10T 29/49071 by winding or coiling
• CPC Class Codes: Y10T 29/49073 by assembling coil and core
• CPC Class Codes: Y10T 29/49158 with molding of insulated base
• CPC Class Codes: Y10T 29/49172 by molding of insulating material
• CPC Class Codes: Y10T 29/49176 with molding of electrically insulating material
• CPC Class Codes: Y10T 29/4922 with molding of insulation
• CPC Class Codes: Y10T 29/49261 : by composite casting or molding
• CPC Class Codes: Y10T 29/49277 : including casting or molding
• CPC Class Codes: Y10T 428/11 : Magnetic recording head
• CPC Class Codes: Y10T 428/32 : Composite [nonstructural laminate] of inorganic material having metal-compound-containing layer and having defined magnetic layer

Abstract

The present invention provides a composite magnetic body containing metallic magnetic powder and thermosetting resin and having a packing ratio of the metallic magnetic powder of 65 vol % to 90 vol % and an electrical resistivity of at least 10⁴ Ω·cm. When a coil is embedded in this composite magnetic body, a miniature magnetic element can be obtained that has a high inductance value and is excellent in DC bias characteristics.

Claims

1. A method of manufacturing a magnetic element comprising a composite magnetic body containing metallic magnetic powder and thermosetting resin and having a packing ratio of the metallic magnetic powder of 65 vol % to 90 vol % and an electrical resistivity of at least 10⁴ Ω

·

cm, and a coil embedded in the composite magnetic body, the method comprising;

obtaining a mixture including metallic magnetic powder and thermosetting resin present in an uncured state;

heating the mixture containing the metallic magnetic powder and the thermosetting resin present in the uncured state in a range between 65°

C. and 200°

C.

granulating the mixture containing the metallic magnetic powder a the thermosetting resin;

obtaining a molded body by pressure-molding the mixture to embed the coil; and

curing the thermosetting resin by heating the molded body.

2. The method of manufacturing a magnetic element according to claim 1, wherein the thermosetting resin whose main component in the uncured state is powder at ordinary temperature is mixed, without being dissolved in a solvent, with a remaining portion of the material containing the metallic magnetic powder.

3. The method of manufacturing a magnetic element according to claim 1, wherein the main component of the thermosetting resin is a liquid at ordinary temperature.