Inductor and its manufacturing method

• US 7,786,834 B2
• Filed: 11/13/2008
• Issued: 08/31/2010
• Est. Priority Date: 11/15/2007
• Status: Active Grant

• Current Assignee: Taiyo Yuden Company Limited (Taiyo Yuden Co)
• Original Assignee: Taiyo Yuden Company Limited (Taiyo Yuden Co)
• Inventors: Ogawa, Hideki, Okino, Yoshikazu, Yagasaki, Toshiyuki, Wada, Kouichirou, Kashiwa, Tomoo, Tosaka, Sholchi
• Primary Examiner(s): NGUYEN, TUYEN T
• Application Number:
  US12/269,883
• Publication Number:
  US 20090128275A1
• Time in Patent Office: 656 Days
• Field of Search: 336/65, 336/83, 336/90, 336/96, 336/192, 336/200, 336/232
• US Class Current: 336/192
• CPC Class Codes: H01F 17/04 with magnetic core
• CPC Class Codes: H01F 2017/048 with encapsulating core, e.g. made of resin and magnetic powder
• CPC Class Codes: Y10T 29/49071 by winding or coiling

Abstract

An inductor 10 has a magnetic body 11 of a rectangular solid shape and a coil 12 embedded in the magnetic body 11. The coil 12 integrally has a part constituted by a helically wound coil wire, two leader parts 12a provided at the two ends of the wound part, and terminal parts 13 connected to the ends of the leader parts and wider than the leader parts 12a, where the boundary between each leader part 12a and each terminal part 13 is positioned in the magnetic body 11, and the end of each terminal part 13 is exposed from the corresponding side face of the magnetic body 11 and folded in an L shape along the side face and bottom face.

Claims

1. An inductor with a magnetic body and a coil embedded in the magnetic body, wherein the coil integrally has a part constituted by a helically wound coil wire, two leader parts provided at two respective ends of the wound coil wire, and terminal parts connected to respective ends of the leader parts and having a width wider than that of the respective leader parts, where a boundary between each leader part and each terminal part is positioned inside the magnetic body and each terminal part is partially exposed from a surface of the magnetic body,

wherein the coil wire comprises a metal wire and an insulation sheath provided on a surface of the metal wire, and each terminal part comprises a wide part constituted by a part of the metal wire at the end of the coil wire being crushed flat and a soldered part covering the wide part, and

wherein the wide part of each terminal part is comprised of two or more adjoining wide parts.

2. The inductor according to claim 1, wherein the coil is embedded in the magnetic body, except for an end of each terminal part which is exposed from the surface of the magnetic body, and the exposed end of each terminal part is folded along the surface of the magnetic body.

3. The inductor according to claim 1, wherein each terminal part of the coil is bent/shaped and partially exposed from the surface of the magnetic body.

4. The inductor according to claim 1, wherein the magnetic body has a rectangular solid shape.

5. The inductor according to claim 2, wherein the exposed end of each terminal part is folded in an L shape along the surface of the magnetic body.

6. A method for manufacturing the inductor with a magnetic body and a coil embedded in the magnetic body as defined in claim 1, comprising:

as a coil forming process, helically winding a coil wire to integrally form a wound part, two leader parts at respective ends of the wound part, and terminal parts connected to the respective leader parts and being wider than the leader parts, wherein the coil wire has a metal wire and an insulation sheath provided on a surface of the metal wire, and the coil forming process comprises a step of partially removing the insulation sheath at each end of the coil wire to expose a part of the metal wire and crushing the exposed part of metal wire flat, and a step of applying molten solder to cover the metal wire before or after the crushing step and then cure the solder, wherein the coil forming process further comprises a step of folding the exposed part of the metal wire once or multiple times to form the two or more adjoining wide parts of each terminal part;

as a magnetic-body material forming process, pressure-forming a magnetic body material by embedding the coil wire in the pressure-formed body so that a boundary between each leader part and each terminal part of the coil wire is positioned in the pressure-formed body and each terminal part of the coil wire is partially exposed from the pressure-formed body; and

as a magnetic-body forming process, curing the pressure-formed body in which the coil wire is embedded to form a magnetic body.

7. The inductor manufacturing method according to claim 6, wherein in the magnetic-body material forming process, the coil wire is embedded in the pressure-formed body except for an end of each terminal part which is exposed from the terminal part, and the method further comprises after the magnetic-body forming process a step of folding the exposed end of each terminal part along the surface of the magnetic body.

8. The inductor according to claim 1, wherein the two or more adjoining wide parts overlap each other as viewed in an axial direction of the helically wound coil wire, and entirely covered by the solder part.

9. The inductor according to claim 8, wherein the two leader parts extend from the part constituted by the helically wound coil wire in opposite directions.