Surface-mount inductor

• US 10,049,809 B2
• Filed: 11/19/2015
• Issued: 08/14/2018
• Est. Priority Date: 11/21/2014
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Kitamura, Kazuhisa
• Primary Examiner(s): Enad, Elvin G
• Assistant Examiner(s): Barnes, Malcolm
• Application Number:
  US14/946,146
• Publication Number:
  US 20160148741A1
• Time in Patent Office: 999 Days
• CPC Class Codes: H01F 27/02 Casings
• CPC Class Codes: H01F 27/292 Surface mounted devices

Abstract

A surface-mount inductor including a coil formed by winding a rectangular wire, and a mounting body for accommodating the coil, the coil having first rolls of the wire wound in a two-roll arrangement, second rolls being wound at positions shifted away from the first rolls along the winding axis, and lead ends brought out from the outermost turn of the second rolls; the mounting body containing a protruded portion for inserting into the winding axis of the coil, and a pair of bottomed magnetic cores having slits respectively, the protruded portion being inserted into the winding axis of the coil so that the mounting body is embedded in the coil with sealant to incorporate the magnetic cores with the coil and to expose the core mounting face of the magnetic cores therefrom, as well as a method for manufacturing the same.

Claims

1. A surface-mount inductor including a coil formed by winding a rectangular wire around the winding axis, and a mounting body for accommodating the coil, comprising:

the coil including first rolls of the wire wound in a two-roll arrangement, both ends of the wire being positioned at the outermost turns, and second rolls, whose inner diameter is equal to or larger than the outer diameter of the first rolls, wound at positions spaced away from the first rolls along the winding axis, and lead ends brought out from the outermost turns of the second rolls;

outermost turns of the first rolls being in contact with at least part of innermost turns of the second rolls, and

the mounting body including a protruded portion for inserting into the winding axis of the coil and a core mounting face, wherein a pair of bottomed magnetic cores each having a recess on an exterior surface and each having slits for bringing out the lead ends therethrough is fitted to the coil in such a manner that the protruded portion is inserted into the winding axis of the coil so that the mounting body is formed to seal the coil with sealant to incorporate the magnetic cores with the coil and to expose the core mounting face of the magnetic cores therefrom, wherein an inside and an outside of the mounting body is sealed with sealant only;

wherein the coil is incorporated in the mounting body in such a manner that the winding axis of the coil is parallel with the body mounting face of the mounting body, a gap between the coil and the mounting body is filled with the sealant, the lead ends extend to the core mounting face and the surfaces adjacent to the core mounting face, and the lead ends extending to the surface adjacent to the core mounting face are sealed with the sealant while the lead ends are placed in the recesses on the exterior surface of the magnetic cores.

2. The surface-mount inductor claimed in claim 1, wherein the coil comprises plural pairs of the second rolls.

3. The surface-mount inductor claimed in claim 1, wherein the lead ends are brought out to the peripheral extending directions of the coil, extend in opposite directions in a plane parallel with the winding axis, with the tips of the lead ends being folded.

4. The surface-mount inductor claimed in claim 1, wherein the core mounting face is covered with the sealant so as to expose the surface of the lead ends of the coil.

5. The surface-mount inductor claimed in claim 1, wherein the lead ends of the coil extending over the core mounting face constitute external terminals.

6. The surface-mount inductor claimed in claim 1, wherein external terminals are provided by covering the lead ends, which extend over the core mounting face, with conductors.

7. The surface-mount inductor claimed in claim 1, wherein a pair of metal bodies which cover the upper, end and side surfaces of the mounting body and which lower ends reach the same level as the surface of the external terminals provided at the body mounting face.

8. A surface-mount inductor including a coil formed by winding a rectangular wire around the winding axis, and a mounting body which has a body mounting face for accommodating the coil, comprising:

the coil including first rolls of the wire wound in a two-roll arrangement, both ends of the wire being positioned at the outermost turn, second rolls, whose inner diameter is equal to or larger than the outer diameter of the first rolls, which are wound at positions shifted away from the first rolls along the winding axis, third rolls wound to have an inner diameter equal to or larger than the outer diameter of the second rolls, and lead ends brought out from the outermost turn of the third rolls;

outermost turns of the first rolls being in contact with at least part of innermost turns of the second rolls, outermost turns of the second rolls being in contact with at least part of innermost turns of the third rolls, and

the mounting body including a protruded portion for inserting into the winding axis of the coil and a core mounting face, wherein a pair of bottomed magnetic cores each having a recess on an exterior surface and each having slits for bringing out the lead ends therethrough is combined with the coil in such a manner that the protruded portion is inserted into the winding axis of the coil so that the mounting body is formed to seal the coil with sealant to incorporate the magnetic cores with the coil and to expose the core mounting face of the magnetic cores therefrom, wherein an inside and an outside of the mounting body is sealed with sealant only;

wherein the coil is incorporated in the mounting body in such a manner that the winding axis of the coil is parallel with the body mounting face of the mounting body, a gap between the coil and the mounting body is filled with the sealant, and that the lead ends extend to the core mounting face and to the surfaces adjacent to the core mounting face, the lead ends extending to the surface adjacent to the core mounting face being sealed with the sealant while the lead ends are placed in the recesses on the exterior surface of the magnetic cores.

9. The surface-mount inductor claimed in claim 8, wherein the second rolls of the coil are obliquely inclined along the winding axis of the coil.

10. The surface-mount inductor claimed in claim 8, wherein the lead ends are brought out to the peripheral extending directions of the outermost turn of the coil, extend in opposite directions in a plane parallel with the winding axis of the coil, with the tips of the lead ends being folded.

11. The surface-mount inductor claimed in claim 8, wherein the core mounting face is covered with the sealant so as to expose the surface of the lead ends of the coil.

12. The surface-mount inductor claimed in claim 8, wherein the lead ends of the coil extending over the core mounting face constitute external terminals.

13. The surface-mount inductor claimed in claim 8, wherein the external terminals are provided by covering the lead ends, which extend over the core mounting face, with conductors.

14. The surface-mount inductor claimed in claim 8, wherein a pair of metal bodies which cover the upper, side and end surfaces of the mounting body, and which lower ends of the metal bodies reach the same level as the surface of the external terminals which are provided at the body mounting face.

15. A method for manufacturing a surface-mount inductor including a coil formed by winding a rectangular wire, and a mounting body for accommodating the coil, comprising the steps of:

forming a coil having first rolls, second rolls and lead ends, by contacting the median portion of the wire to the spindle of a winding machine, to wind the first rolls in a manner that both ends of the wire are positioned at the outermost turn, that the second rolls, whose inner diameter is equal to or larger than the outer diameter of the first rolls, are wound at positions on opposite sides along the winding direction of the coil, and that the lead ends are brought out from the outermost turn of the second rolls; and

forming a mounting body by combining a coil and a pair of magnetic cores each having a recess on an exterior surface and each having a mounting face, the magnetic cores having a protruded portion for inserting into the winding axis of the coil and slits for bringing out the lead ends of the coil to the mounting face therethrough, by arranging the coil and the cores in a mold, and then by filling the mold with sealant while exposing the core mounting face so as to seal an inside and an outside of the mounting body to make the mounting body;

thus, the coil is inserted in the mounting body in such a manner that the winding axis of the coil is parallel with the body mounting face, and that the lead ends extend to the core mounting face and the surface adjacent to the core mounting face, the lead ends of the coil extending to the surface adjacent to the core mounting face being embedded with the sealant with the lead ends being placed in the recesses on the exterior surface of the magnetic cores.

16. A method for manufacturing a surface-mount inductor including a coil formed by winding a rectangular wire, and a mounting body for accommodating the coil, comprising the steps of:

forming a coil having first rolls, second rolls and lead ends, by contacting the median portion of the wire to the spindle of a winding machine, to wind the first rolls in a manner that both ends of the wire are positioned at the outermost turn, the second rolls, whose inner diameter is equal to or larger than that of the second rolls, are wound at positions on opposite sides along the winding direction of the coil, that the third rolls, whose inner diameter is equal to or larger than the outer diameter of the second rolls, are wound at the positions each on opposite sides along the winding direction of the coil, and that the lead ends are brought out from the outermost turn of the third rolls; and

forming a mounting body by fitting a coil and a pair of magnetic cores each having a recess on an exterior surface and each having a mounting face, the magnetic cores having a protruded portion for inserting into the winding axis of the coil and slits for bringing out the lead ends of the coil to the mounting face therethrough, by arranging the coil and the cores in a mold, and then filling the mold with sealant while exposing the core mounting face so as to seal an inside and an outside of the mounting body to make the mounting body;

thus, the coil is inserted in the mounting body in such a manner that the winding axis of the coil is parallel with the body mounting face, and that the lead ends extend to the core mounting face and the surface adjacent to the core mounting face, the lead ends of the coil extending to the surface adjacent to the core mounting face being embedded with the sealant with the lead ends being placed in the recesses on the exterior surface of the magnetic cores.