Inductance element, method for manufacturing the same, and switching power supply using the same

• US 8,125,305 B2
• Filed: 05/20/2008
• Issued: 02/28/2012
• Est. Priority Date: 05/21/2007
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Materials Company Limited (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Materials Company Limited (Toshiba Corporation)
• Inventors: Saito, Tadao, Sakai, Kazumi, Yamada, Katsuhiko
• Primary Examiner(s): MAI, ANH T
• Application Number:
  US12/599,315
• Publication Number:
  US 20110205765A1
• Time in Patent Office: 1,379 Days
• Field of Search: 336/229, 336/96, 336/92, 336/90, 296/021
• US Class Current: 336/90
• CPC Class Codes: H01F 17/06 with core substantially closed in itself, e.g. toroid
• CPC Class Codes: H01F 2017/065 Core mounted around conductor to absorb noise, e.g. EMI filter
• CPC Class Codes: H01F 27/266 Fastening or mounting the core on casing or support on coil H01F27/30
• CPC Class Codes: H01F 27/306 Fastening or mounting coils or windings on core, casing or other support
• CPC Class Codes: H02M 3/338 in a self-oscillating arrangement H02M3/337 takes precedence
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

An inductance element (1) includes a doughnut-shaped magnetic core (2) and a bottomed container (3) for housing the doughnut-shaped magnetic core (2). The bottomed container (3) has a cylindrical outer wall portion, a cylindrical inner wall portion, a bottom portion, an open section and a hollow portion. The open section of the bottomed container (3) is covered with an adhesive portion (4) for integrally fixing the doughnut-shaped magnetic core (2) and the bottomed container (3). The adhesive portion (4) has an extended portion (4a) extended in the cylindrical inner wall portion. The ratio (B/A) of a length (B) of the extended portion (4a) to a height (A) of the cylindrical inner wall portion is in a range of 0.1 to 0.5.

Claims

1. An inductance element, comprising:

a doughnut-shaped magnetic core;

a bottomed container having a cylindrical outer wall portion, a cylindrical inner wall portion arranged within the cylindrical outer wall portion, a bottom portion disposed at an end of each of the cylindrical outer wall portion and the cylindrical inner wall portion to close a space between them, an open section provided at the other end of each of the cylindrical outer wall portion and the cylindrical inner wall portion and a hollow portion disposed within the cylindrical inner wall portion, wherein the doughnut-shaped magnetic core is housed between the cylindrical outer wall portion and the cylindrical inner wall portion; and

an adhesive portion, disposed on the side of the open section of the bottomed container, integrally fixing the doughnut-shaped magnetic core and the bottomed container,

wherein the adhesive portion has an extended portion extended into the cylindrical inner wall portion, and a ratio (B/A) of a length (B) of the extended portion to a height (A) of the cylindrical inner wall portion is in a range of 0.1 to 0.5.

2. The inductance element according to claim 1,

wherein the open section of the bottomed container including the hollow portion is covered with the adhesive portion.

3. The inductance element according to claim 2,

wherein at least a lead insertion part selected from a concave, a hole and a notch is formed in the adhesive portion.

4. The inductance element according to claim 1,

wherein the doughnut-shaped magnetic core has a wound body of a magnetic alloy ribbon or a stacked body of magnetic alloy ribbons.

5. The inductance element according to claim 4,

wherein the magnetic alloy ribbon is provided with an amorphous magnetic alloy ribbon.

6. The inductance element according to claim 1,

wherein the adhesive portion penetrates to a range of 5 to 30% of a cross-sectional area of the doughnut-shaped magnetic core.

7. The inductance element according to claim 1,

wherein the adhesive portion is formed of a cured body of an acryl modified silicone resin-based adhesive.

8. The inductance element according to claim 1,

wherein a conductive lead portion is inserted into the hollow portion of the bottomed container.

9. The inductance element according to claim 1,

wherein a ratio (C/A) of a height (C) of the cylindrical outer wall portion to the height (A) of the cylindrical inner wall portion is in a range of 0.6 to 1.3.

15. A switching power supply comprising the inductance element according to claim 1 as a noise suppression element.

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

housing a doughnut-shaped magnetic core into a bottomed container having a cylindrical outer wall portion, a cylindrical inner wall portion disposed within the cylindrical outer wall portion, a bottom portion disposed at an end of each of the cylindrical outer wall portion and the cylindrical inner wall portion to close a space between them, an open section provided at the other end of each of the cylindrical outer wall portion and the cylindrical inner wall portion and a hollow portion disposed within the cylindrical inner wall portion;

coating an adhesive on a side of the open section of the bottomed container in which the doughnut-shaped magnetic core is housed; and

forming an adhesive portion, which integrally fixes the doughnut-shaped magnetic core and the bottomed container, by drying the adhesive for curing.

11. The method for manufacturing an inductance element according to claim 10,

wherein the adhesive is dried at a temperature in a range of 90 to 150°

C.

12. The method for manufacturing an inductance element according to claim 10,

wherein the adhesive portion is formed to extend into the cylindrical inner wall portion, and a ratio (B/A) of a length (B) of a portion having the adhesive portion extended to a height (A) of the cylindrical inner wall portion is in a range of 0.1 to 0.5.

13. The method for manufacturing an inductance element according to claim 10,

wherein the open section including the hollow portion of the bottomed container is covered with the adhesive portion.

14. The method for manufacturing an inductance element according to claim 10, further comprising,

forming at least a lead insertion part selected from a concave, a hole and a notch, in the adhesive portion.