INDUCTANCE PART AND METHOD FOR MANUFACTURING THE SAME

• US 20100253463A1
• Filed: 12/11/2008
• Published: 10/07/2010
• Est. Priority Date: 12/12/2007
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Takagi, Kiyoshi, Shimomura, Satoru, Oonishi, Kazuaki
• Granted Patent: US 8,339,227 B2
• Time in Patent Office: Days
• US Class Current: 336/200
• CPC Class Codes: H01F 17/04 with magnetic core
• CPC Class Codes: H01F 17/06 with core substantially closed in itself, e.g. toroid
• CPC Class Codes: H01F 2017/048 with encapsulating core, e.g. made of resin and magnetic powder
• CPC Class Codes: H01F 27/2847 Sheets; Strips H01F27/2866 takes precedence
• CPC Class Codes: H01F 27/292 Surface mounted devices
• CPC Class Codes: H01F 3/10 Composite arrangements of magnetic circuits
• CPC Class Codes: H01F 41/005 Impregnating or encapsulating insulating of windings H01F41/12
• 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: Y10T 29/49076 From comminuted material

Abstract

Disclosed is an inductance part including a coiled conductor formed from a metal conductor, a magnetic body formed by pressure-molding a mixture of metal magnetic powder and bonding material in such a manner that the coiled conductor is embedded in the mixture, and a terminal derived from the coiled conductor. The coiled conductor is formed in a single layer with no insulating film on its surface. The metal magnetic powder of the magnetic body penetrates into the surface of the coiled conductor so as to make the filling factor of the metal magnetic powder in the magnetic body not less than 80% by volume.

Claims

1. An inductance part comprising:

a coiled conductor formed from a metal conductor;

a magnetic body formed by pressure-molding a mixture of metal magnetic powder and bonding material in such a manner that the coiled conductor is embedded in the mixture; and

a terminal derived from the coiled conductor, wherein

the coiled conductor is formed in a single layer with no insulating film on a surface thereof, and

the metal magnetic powder of the magnetic body penetrates into a surface of the coiled conductor so as to make a filling factor of the metal magnetic powder in the magnetic body not less than 80% by volume.

2. The inductance part of claim 1, wherein

the coiled conductor is made of a softer material than the metal magnetic powder.

3. The inductance part of claim 1, wherein

the magnetic body has a higher density in a vicinity of the coiled conductor than an average density of the magnetic body.

4. The inductance part of claim 1, wherein

the metal magnetic powder has an electrical insulating material interposed between particles thereof.

5. The inductance part of claim 1, wherein

the magnetic body is subjected to straightening annealing to remove internal strains of the metal magnetic powder.

6. The inductance part of claim 1, wherein

the magnetic body includes an upper surface portion above the coiled conductor, a lower surface portion below the coiled conductor, and an intermediate portion besides the coiled conductor, the upper surface portion and the lower surface portion having a higher density than the intermediate portion.

7. The electronic component of claim 6, wherein

the intermediate portion of the magnetic body has a larger thickness than the upper surface portion and the lower surface portion.

8. The inductance part of claim 1, wherein

the coiled conductor includes bias portions at both ends thereof connected to the terminals, the bias portions each including an upward-bent part bent upward and a laterally-bent part bent laterally;

the coiled conductor has a center thereof located at a substantial center of an upper surface and a lower surface of the magnetic body; and

the terminals are biased toward a top of side surfaces of the magnetic body and derived from the coiled conductor.

9. The inductance part of claim 1, wherein

the coiled conductor includes a projection at an edge of one of an upper surface and a lower surface thereof, the projection extending in a direction perpendicular to one of the upper surface and the lower surface thereof.

10. A method for manufacturing an inductance part, comprising:

forming a coiled conductor from a metal conductor;

forming a magnetic body by pressure-molding a mixture of metal magnetic powder and bonding material in such a manner that the coiled conductor is embedded in the mixture;

heat treating a pressure-molded body; and

forming a terminal derived from the coiled conductor, wherein

in the step of forming the coiled conductor, the coiled conductor is formed in a single layer with no insulating film on a surface thereof, and

in the step of forming the magnetic body, the pressure-molding is performed in such a manner that the metal magnetic powder of the magnetic body penetrates into a surface of the coiled conductor so as to make a filling factor of the metal magnetic powder in the magnetic body not less than 80% by volume.

11. The method for manufacturing an inductance part of claim 10, wherein

in the step of forming the magnetic body, pressure-molding is performed in such a manner that the magnetic body has a higher density in a vicinity of the coiled conductor than an average density of the magnetic body.

12. The method for manufacturing an inductance part of claim 10, wherein

in the step of heat treating, heat treatment is performed at a temperature not less than 600°

C. and lower than a temperature at which the coiled conductor and the metal magnetic powder are diffused by heat.