JP2009094338A - Magnetic element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a height of a magnetic element to a height level of a horizontally-mounted core. <P>SOLUTION: A magnetic element has a first core 1 and a second core 2. The first core 1 has a core part around which a winding is wound, and two flanges respectively arranged at each of both ends and respectively formed with a bottom face and side faces. The second core 2 has a first face arranged oppositely to the side face of one flange of the first core 1, and a second face oppositely arranged to the side face of the other flange of the first core 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a magnetic element.

  Inductors used for portable electronic devices are becoming increasingly low profile. However, in an inductor using a drum core, it is necessary to have a thickness to secure strength, so it is difficult to further reduce the height of a vertically placed drum core with one flange as the bottom surface. is there. Therefore, an inductor having a horizontal drum core has been proposed (see, for example, Patent Document 1).

  In the inductor in Patent Document 1, a flat core is bonded by applying an ultraviolet curable resin to the upper surfaces of two flanges of a horizontal drum core.

JP 2000-133522 A

  However, in the case of the inductor described above, since the flat core is mounted on the horizontal drum core, it is difficult to reduce the height to the height of the horizontal drum core.

  The present invention has been made in view of the above problems, and an object of the present invention is to obtain a magnetic element that can be reduced in height to the height of a horizontally placed core.

  In order to solve the above problems, the present invention is configured as follows.

  The magnetic element according to the present invention has a first core and a second core. The first core has two cores, each of which has a core portion wound with a winding, and a side surface and a bottom surface substantially parallel to the axial direction of the core portion. Part. The second core is disposed so as to be opposed to the side surface of the first flange part of the first core and the side surface of the other collar part of the first core. And having a surface.

  Thereby, the magnetic element can be reduced in height to the height of the horizontally placed first core.

  In addition to the above magnetic element, the magnetic element according to the present invention may be as follows. In this case, the height of the second core is the same as or lower than the heights of the two flange portions of the first core.

  Thereby, the magnetic element can be reduced in height to the height of the horizontally placed first core.

  The magnetic element according to the present invention may be as follows in addition to any of the above magnetic elements. In this case, the second core is a C-shaped core. Then, the side surfaces of the two flange portions of the first core and the side surface of the core portion of the first core are on the same plane.

  Thereby, since 1 side surface of a 1st core becomes the same surface, the process at the time of shaping | molding can be simplified.

  According to the present invention, the height of the horizontal drum core can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing a magnetic element according to Embodiment 1 of the present invention. The magnetic element according to the first embodiment is a horizontally placed inductor having the drum core 1 and the C-shaped core 2 shown in FIG. The drum core 1 and the C-shaped core 2 are joined via a magnetic gap (not shown). In FIG. 1, the windings and terminals are not shown.

  The drum core 1 and the C-shaped core 2 are shaped as shown in FIG. 1, and are manufactured by sintering a magnetic material such as ferrite formed by a mold.

  FIG. 2 is a perspective view showing the drum core 1 in FIG.

  The drum core 1 is provided with a core portion 11 around which a winding is wound, and two flange portions 12, 13 each having a bottom surface 12a, 13a and side surfaces 12b, 13b. And have. The bottom surfaces 12 a and 13 a are planes substantially parallel to the axial direction of the core portion 11.

  In Embodiment 1, the core part 11 of the drum core 1 has a substantially rectangular parallelepiped shape. In FIG. 1 and FIG. 2, the core portion 11 is drawn as a rectangular parallelepiped, but the sides may be rounded by a flat surface or a curved surface.

  In the first embodiment, the flange portion 12 of the drum core 1 has a substantially rectangular parallelepiped shape. Accordingly, the flange portion 12 has a bottom surface, an upper surface, and four side surfaces, is continuous to the core portion 11 at one of the side surfaces, and is joined to the C-shaped core 2 through a gap at another side surface 12b. . Similarly, the collar part 13 has a substantially rectangular parallelepiped shape. Therefore, the collar portion 13 has a bottom surface, an upper surface, and four side surfaces, is continuous to the core portion 11 at one of the side surfaces, and is joined to the C-shaped core 2 via a gap at another side surface 13b. . The bottom surfaces of the flange portions 12 and 13 together with the bottom surface of the C-shaped core 2 become the bottom surface of the magnetic element, and come into contact with a mounting surface such as a substrate when the magnetic element is mounted. In FIGS. 1 and 2, the flanges 12 and 13 are drawn as rectangular parallelepipeds, but the sides other than the side surfaces 12 b and 13 b may be chamfered by a flat surface or a curved surface. Further, as described above, since the drum core 1 is joined to the C-shaped core 2 through a gap, the AL value and the DC superimposition characteristics can be changed by adjusting the width of the gap.

  In Embodiment 1, the collar part 12 and the collar part 13 have the same shape. Therefore, the collar part 12 and the collar part 13 have the same height, and the side surface 12b of the collar part 12 and the side surface 13b of the collar part 13 are on the same surface. Furthermore, in the first embodiment, the side surface 12b of the flange portion 12, the side surface 13b of the flange portion 13, and the side surface 11a of the core portion 11 are on the same plane.

  The difference between the height of the flange portions 12 and 13 and the height of the core portion 11 is such that the wound winding does not protrude beyond the top or bottom surface of the flange portions 12 and 13 in the height direction. The height of the collars 12 and 13 is 1 mm or less, for example, 0.6 mm.

  FIG. 3 is a perspective view showing the C-shaped core 2 in FIG. The C-shaped core 2 has a shape in which a concave portion 2a is formed in a substantially rectangular parallelepiped. The depth W of the recess 2 a of the C-shaped core 2 is determined so that the winding wound around the drum core 1 does not contact the C-shaped core 2. A first surface 2 b is formed as a flat surface at one end of the C-shaped core 2, and a second surface 2 c is formed as a flat surface at the other end of the C-shaped core 2. The height of the C-shaped core 2 is set equal to or lower than the maximum height of the flanges 12 and 13 of the drum core 1.

  When fixing the C-shaped core 2 to the drum core 1, the surface 2 b is disposed with a gap from the side surface 12 b of the flange portion 12 of the drum core 1, and the surface 2 c is disposed on the side surface 13 b of the flange portion 13 of the drum core 1. In contrast, they are arranged with a gap therebetween. Therefore, the surface 2b has a shape that matches the side surface 12b, and the surface 2c has a shape that matches the side surface 13b.

  A magnetic element is manufactured by winding a winding around the core 11 of the drum core 1 and joining the drum core 1 and the C-shaped core 2 via a gap. The gap is formed by a nonmagnetic spacer disposed between the drum core 1 and the C-shaped core 2, a nonmagnetic adhesive used for joining the drum core 1 and the C-shaped core 2, or the like. Thereby, the magnetic path which passes the core part 11 and the collar parts 12 and 13 of the drum core 1, the gap, and the C-shaped core 2 is obtained.

  4 is a cross-sectional view taken along the line A-A ′ of the magnetic element shown in FIG. 1, and shows a cross section in the direction perpendicular to the longitudinal direction of the core 11 at the center of the core 11. A space is secured around the core portion 11 of the drum core 1 by the flange portions 12 and 13 and the recessed portion 2a of the C-shaped core 2, and the wound winding as shown in FIG. It is arranged without protruding to.

  FIG. 5 is a front view of the magnetic element of FIG. As shown in FIG. 5, the winding 21 is wound around the core portion 11. In the first embodiment, the winding 21 is a single layer winding. One end of the winding 21 is fixed and electrically connected to a terminal 22 formed on the side surface facing the side surface 12b in contact with the C-shaped core in the flange portion 12 by soldering or the like. The other end of the winding 21 is fixed and electrically connected to a terminal 23 formed on a side surface facing the side surface 13b in contact with the C-shaped core in the flange portion 13 by soldering or the like. The terminals 22 and 23 are formed, for example, by applying and baking a silver paste on the flange portions 12 and 13. Further, the terminals 22 and 23 may be metal pieces fixed to the drum core 1. Further, the terminals 22 and 23 are electrically connected to the substrate via lead wires or directly.

  As described above, according to the first embodiment, the drum core 1 as the first core is disposed on the core portion 11 around which the winding 21 is wound, and one on each end of the core portion 11. Have two bottom portions 12 and 13 formed with bottom surfaces 12a and 13a and side surfaces 12b and 13b. The C-shaped core 2 as the second core has a gap with respect to the side surface 13b of the flange part 13 of the drum core 1 and the side surface 13b of the flange part 13 of the drum core 1 with a gap provided between the side surface 12b of the flange part 12 of the drum core 1. And a second surface 2c arranged with a gap therebetween. Thereby, a magnetic element can be reduced in height to the height of the horizontal drum core 1.

  Further, according to the first embodiment, the height of the C-shaped core 2 is equal to or lower than the height of the two flange portions 12 and 13 of the drum core 1. Thereby, the magnetic element can be reduced in height to the height of the horizontally placed drum core 1.

  Further, according to the first embodiment, the side surfaces 12b and 13b of the two flange portions 12 and 13 of the drum core 1 and the side surface 11a of the core portion 11 are on the same plane. Thereby, since one side surface of the drum core 1 becomes the same surface, the process at the time of shaping | molding can be simplified. That is, since one side surface of the drum core 1 is the same surface, it is not necessary to process unevenness on the surface.

Embodiment 2. FIG.
The magnetic element according to the second embodiment of the present invention has an I-shaped core instead of the C-shaped core 2 of the first embodiment. FIG. 6 is a perspective view showing a magnetic element according to Embodiment 2 of the present invention. In FIG. 6, the drum core 101 is a core in which the flange portion 112 and the flange portion 113 protrude in both the front direction and the back direction. The I-shaped core 102 is a substantially rectangular parallelepiped rod-shaped core. In the second embodiment, the two surfaces (regions) in the side surface 102a of the I-shaped core 102 are joined to the drum core 101 with a gap therebetween.

  The material and production of the drum core 101 and the I-shaped core 102 are the same as those of the drum core 1 and the C-shaped core 2. Further, windings, terminals, and the like in the magnetic element according to the second embodiment are configured in the same manner as in the first embodiment.

  As described above, according to the second embodiment, the drum core 101 serving as the first core is arranged on the core portion around which the winding is wound, one on each end of the core portion, and each has a bottom surface. It has two flange parts 112 and 113 formed with side surfaces. The I-shaped core 102 as the second core includes a first surface (a part of the side surface 102 a) disposed with a gap with respect to the side surface of the flange portion 112 of the drum core 101 and the side surface of the flange portion 113 of the drum core 101. And a second surface (another part of the side surface 102a) disposed with a gap therebetween. Thereby, the magnetic element can be reduced in height to the height of the horizontal drum core 101.

  Further, according to the second embodiment, the height of the I-shaped core 102 is the same as or lower than the heights of the two flange portions 112 and 113 of the drum core 101. Thereby, the magnetic element can be lowered in height to the horizontal drum core 101.

Embodiment 3 FIG.
The magnetic element according to the third embodiment of the present invention uses the same core as the drum core 1 instead of the C-shaped core 2 of the first embodiment. FIG. 7 is a perspective view showing a magnetic element according to Embodiment 3 of the present invention. As shown in FIG. 7, in the third embodiment, a core 201 as a second core is joined to the drum core 1 through a gap in the same manner as in the first embodiment. The core 201 is the same core as the drum core 1. That is, the core 201 is formed of the same shape and the same material as the drum core 1.

  Note that windings, terminals, and the like in the magnetic element according to the third embodiment are configured in the same manner as in the first embodiment.

  As described above, according to the third embodiment, since two identical cores 1 and 201 are used and other shapes of cores are not used, one type of core may be manufactured, and a magnetic element is manufactured. Cost can be lowered.

  Each embodiment described above is a preferred example of the present invention, but the present invention is not limited to these, and various modifications and changes can be made without departing from the scope of the present invention. It is.

  For example, in the first embodiment, the winding 21 is wound in one layer, but may be wound in a plurality of layers instead.

  Further, in each of the above embodiments, the shape of the core portion of the drum cores 1 and 101 is a substantially rectangular parallelepiped, but may instead be a shape such as an elliptic cylinder or a cylinder.

  Moreover, in each said embodiment, although the shape of the collar parts 12, 13, 112, 113 of the drum core 1,101 is made into the substantially rectangular parallelepiped, the side surface does not need to be perpendicular | vertical with respect to a bottom face, Further, it may be a curved surface. However, the shapes of the surfaces 2b and 2c of the C-shaped core 2 and the side surface 102a of the I-shaped core 102 are the flange portions 12, 13, 112, It is determined corresponding to the side surface 113.

  In the first embodiment, the C-shaped core 2 is joined to the side surfaces 12b and 13b perpendicular to the side surface continuous to the core portion 11 of the drum core 1 with a gap therebetween. The C-shaped core may be joined to the side surfaces of the flange portions 12 and 13 facing the side surfaces continuous with the core portion 11 of the drum core 1 with a gap therebetween.

  Moreover, in the said Embodiment 1, although the terminals 22 and 23 are arrange | positioned at the side surface of the collar parts 12 and 13, instead, when it is permitted that the height of a magnetic element increases, You may arrange | position on the bottom face of the collar parts 12 and 13. FIG.

  Further, in each of the above-described embodiments, there are two places where the drum core 1 and the C-shaped core 2 are joined, where the drum core 101 and the I-shaped core 102 are joined, and where the drum core 1 and the core 201 are joined. In each of the embodiments described above, the magnetic gap is provided at both of the two joints, but only one of them may be provided. In that case, the other joining portion is joined by an adhesive containing a magnetic material, a spacer, or the like.

  The present invention is applicable to, for example, a power inductor used in a high-frequency DC / DC converter for portable equipment.

It is a perspective view which shows the magnetic element which concerns on Embodiment 1 of this invention. It is a perspective view which shows the drum core in FIG. It is a perspective view which shows the C-shaped core in FIG. It is sectional drawing of the magnetic element shown in FIG. 1, Comprising: It is a figure which shows the cross section in the direction perpendicular | vertical to the longitudinal direction of a core part in the center of a core part. It is a front view of the magnetic element of FIG. It is a perspective view which shows the magnetic element which concerns on Embodiment 2 of this invention. It is a perspective view which shows the magnetic element which concerns on Embodiment 3 of this invention.

Explanation of symbols

1,101 drum core (first core)
2 C-shaped core (second core)
2b 1st surface 2c 2nd surface 11 core part 11a side surface 12, 13, 112, 113 collar part 12a, 13a bottom surface 12b, 13b side surface 21 winding 22, 23 terminal 102 I-shaped core (second core)
201 core (second core)

Claims (3)

A core portion around which the winding is wound, and two flange portions which are respectively arranged at both ends of the core portion and each have a side surface and a bottom surface substantially parallel to the axial direction of the core portion. A first core;
A first surface disposed to face the side surface of one of the flange portions of the first core and a second surface disposed to face the side surface of the other flange portion of the first core. A second core having a surface;
A magnetic element comprising:   The magnetic element according to claim 1, wherein a height of the second core is equal to or lower than a height of the two flange portions of the first core. The second core is a C-shaped core;
The side surfaces of the two flange portions of the first core and the side surfaces of the core portion of the first core are on the same plane;
The magnetic element according to claim 1.

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