JP2010087242A - Coil component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small coil component hardly causing cracks on a molded compact and hardly causing damage on a conductor. <P>SOLUTION: The coil component C includes: a molded compact 10 containing a magnetic material and formed by powder compression molding; a coil 25 disposed in the molded compact 10 and formed by alpha winding; and a conductor 20 having a pair of led-out portions 202, 203 led out from the coil. In the coil 25, the conductor 20 is wound so as to form a plurality of layers in a diameter direction and an axial direction. The pair of inner circumferential portions of the coil 25 are formed by winding the conductor 20 by three or more turns in the axial direction. The winding end of the coil 25 is positioned in the center of the coil 25 in the axial direction of the outer circumference of the coil 25, and the pair of led-out portions 202, 203 are led out along the diameter direction of the coil 25 from the pair of winding ends. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a coil component mounted on an electric device or the like for power supply or noise removal.

Conventionally, patent document 1 is known as such a coil component. The coil component described in Patent Document 1 is formed by coating a coil part with a prismatic exterior part (molded body), and by embedding the coil part in magnetic powder and then pressing the magnetic powder. Is done. Terminal portions are provided at both ends in the axial direction of the coil portion, and each terminal portion has a portion covered with the exterior portion together with the coil portion and a portion exposed from the exterior portion. The coil part is located substantially at the center of the exterior part, and the portions covered by the exterior part of both terminal parts are bent in a step shape. Thereby, both terminal parts will each be exposed from the approximate center in the height direction of the exterior part.
Japanese Unexamined Patent Publication No. 2004-153068

  In the coil component described in Patent Document 1, since the bent portion of each terminal portion is covered with the exterior portion, the dimensions of the exterior portion may be larger than the coil component that is exposed from the exterior portion without bending each terminal portion. . Further, in the coil component described in Patent Document 1, since each terminal portion is bent in a stepped shape, a large load is applied to the bent portion when the magnetic powder is pressure-molded, and the terminal portion may be damaged.

  In the coil component in which each terminal portion is exposed from the exterior portion without being bent, the size of the exterior portion is smaller than that of the coil component described in Patent Document 1, but another problem arises. That is, in such a coil component, since the terminal portion is provided at both ends in the axial direction of the coil portion, when trying to reduce the height of the coil component, the exterior portion becomes thin around the terminal portion and cracks are generated. It may enter.

  An object of the present invention is to provide a small coil component in which a crack is hardly generated in a molded body and a conductor in the molded body is hardly damaged.

  The present invention includes a molded body that includes a magnetic material and is formed by compacting, a coil portion that is disposed inside the molded body and that is formed by alpha winding, and a pair of drawer portions that are drawn from the coil portion. In the coil portion, the conductive wire is wound so as to form a plurality of layers in the radial direction and the axial direction, and the inner peripheral portion of the coil portion winds the conductive wire in the axial direction for three or more turns. The pair of winding ends of the coil portion is formed on the outer peripheral portion of the coil portion and is located in the central portion of the coil portion in the axial direction, and extends from the pair of winding ends along the radial direction of the coil portion. The pair of drawer portions are each drawn out.

  In this coil component, since the coil portion is formed by alpha winding of the conducting wire, the drawing portion of the conducting wire can be easily pulled out from the outer periphery of the coil portion. Moreover, since the coil part is alpha winding, it has a pair of winding ends, and these winding ends are located at the central part of the coil part in the axial direction. Since the pair of drawer portions are pulled out from the end of the pair of windings, the drawer position of each drawer portion can be the central portion of the coil portion in the axial direction.

  Therefore, in the case where the coil portion is arranged at the approximate center of the molded body, the pair of lead portions can be exposed from the center in the height direction of the molded body without being bent. Thereby, the damage of the conducting wire by bending can be prevented. Further, since the bent portion of the conducting wire is not covered with the molded body, the coil component can be reduced in size. Furthermore, since the drawing position of the drawing portion is located in the central portion in the axial direction of the coil portion, the thickness of the molded body around the drawing position can be sufficiently ensured even when the coil component is reduced in height.

  Moreover, in the coil component of this invention, it is suitable that the cross section of conducting wire is circular.

  By using a conducting wire having a circular cross section, twisting does not occur and the winding can be smoothly performed even if the winding is wound so as to have a plurality of layers in the axial direction, compared to a conducting wire having a square cross section. Therefore, it is possible to easily realize an increase in inductance value by increasing the number of turns.

  In the coil component of the present invention, it is preferable that the coil portion is formed by starting to wind the conducting wire from a portion that becomes an inner peripheral portion of the coil portion and that becomes a central portion of the coil portion in the axial direction.

  In this case, the lead-out portion of the conductive wire can be smoothly drawn out from the outer peripheral portion of the coil portion and from the central portion of the coil portion in the axial direction.

  ADVANTAGE OF THE INVENTION According to this invention, it is hard to produce a crack in a molded object, it is hard to produce damage to the conducting wire in a molded object, and a small coil component can be provided.

  Hereinafter, preferred embodiments of a coil component according to the present invention will be described in detail with reference to the drawings.

  The coil component according to the present embodiment is applied to a CPU peripheral circuit of an electronic device such as a notebook personal computer, and is applied with an alternating current having a predetermined frequency (for example, several hundred Hz). FIG. 1 is a perspective view of a coil component C according to the present embodiment. As shown in FIG. 1, the coil component C includes a molded body 10, a conductive wire 20, and terminal fittings 30 and 32.

  The molded body 10 is obtained by compacting magnetic powder. Examples of the magnetic powder include ferrite powder and ferromagnetic metal powder. In particular, the ferromagnetic metal powder is preferable because it has a higher saturation magnetic flux density than the ferrite powder and the DC superposition characteristics are maintained up to a high magnetic field.

  The molded body 10 includes a mounting surface 101 placed on the mounting substrate, a facing surface 102 facing the mounting surface 101, side surfaces 104 and 105 orthogonal to the mounting surface 101, and side surfaces 108 facing the side surfaces 104 and 105. , 109. The side surface 104 and the side surface 105 are chamfered, whereby a side surface 106 is formed between the side surface 104 and the side surface 105. The side surface 108 and the side surface 109 are also chamfered, whereby a side surface 110 is formed between the side surface 108 and the side surface 109.

  Concave portions 103 and 107 are formed on the facing surface 102 of the molded body 10. The recess 103 is formed from a ridge line formed by the side surface 104 and the facing surface 102 toward the center of the facing surface 102. The recess 107 is formed from a ridge formed by the side surface 108 and the facing surface 102 toward the center of the facing surface 102.

  Terminal fittings 30 and 32 are attached to the molded body 10. The terminal fitting 30 has a base portion 301, a joint portion 302, one clamping portion 303, and the other clamping portion 304. The base 301 is disposed along the side surface 104 of the molded body 10. The joint portion 302 extends from the base portion 301 and is disposed along the side surface 106 of the molded body 10. A fusion part 302a is formed in the joint part 302, and one lead part 202 of the conductive wire 20 (to be described later) and the terminal fitting 30 are welded and joined in the fusion part 302a. The sandwiching portion 303 extends from the base portion 301 and is disposed along the concave portion 103 formed on the facing surface 102 of the molded body 10. The sandwiching portion 304 extends from the base portion 301 and is disposed along the mounting surface 101.

  Similar to the terminal fitting 30, the terminal fitting 32 has a base (not shown), a joint (not shown), one clamping part 323, and the other clamping part (not shown). Yes. A base portion of the terminal fitting 32 is disposed along the side surface 108 of the molded body 10. The joint portion of the terminal fitting 32 extends from the base portion of the terminal fitting 32 and is disposed along the side surface 110 of the molded body 10. A fusion part (not shown) is formed in the joint part, and the other lead-out part 203 of the conductor 20 and a terminal fitting 32, which will be described later, are welded and joined in this fusion part. One clamping part 323 of the terminal fitting 32 extends from the base of the terminal fitting 32 and is disposed along a recess 107 formed on the facing surface 102 of the molded body 10. The other sandwiching portion of the terminal fitting 32 extends from the base portion 301 and is disposed along the mounting surface 101.

  A conductive wire (conductive wire) 20 is embedded in the molded body 10. The conducting wire 20 is a round wire made of a copper wire covered with a resin coating, and has a circular cross section. Examples of the resin used for coating include an epoxy-modified acrylic resin.

  FIG. 2A is a plan view of the coil portion 25, and FIG. 2B is a cross-sectional view of the coil portion 25. As shown in FIGS. 1 and 2, the coil part (coil part) 25 is an air-core coil part, and is formed by winding the conductive wire 20 so as to form a plurality of layers in the radial direction and the axial direction. The coil portion 25 is disposed at substantially the center of the molded body 10 and is disposed so that the axial direction (the X direction shown in FIG. 2B) is parallel to the side surfaces 104 to 106 and 108 to 110. .

  FIG. 3 is a view for explaining a winding state of the coil portion 25. As shown in FIG. 3, the coil portion 25 is formed by alpha winding the conducting wire 20. Therefore, the coil part 25 has two winding ends. The pair of winding ends of the coil portion 25 is located at the outer peripheral portion of the coil portion 25 and at the central portion in the axial direction of the coil portion 25, and one lead portion 202 of the conducting wire 20 extends from one winding end. The coil portion 25 is drawn in the radial direction, and the other lead portion 203 is drawn in the radial direction of the coil portion 25 from the other winding end. Here, the central portion in the axial direction of the coil portion 25 refers to a portion excluding both ends 201 a and 201 b in the axial direction of the coil portion 25. The lead-out positions of one lead portion 202 and the other lead portion 203 of the conducting wire 20 from the coil portion 25 do not have to be completely coincident with the center of the coil portion 25 in the axial direction, and are slightly shifted from each other in the axial direction. May be. However, the amount of deviation is preferably 1.5 times or less of the diameter of the conducting wire 20. In the present embodiment, as shown in FIG. 2B, the amount of deviation of the drawing position between the one drawing portion 202 and the other drawing portion 203 is about 0.5 times the diameter of the conducting wire 20.

  As shown in FIGS. 2 and 3, the inner peripheral portion of the coil portion 25 is formed by winding the conductive wire 20 in the axial direction for three or more turns (three turns in the present embodiment). Moreover, the outer peripheral part of the coil part 25 winds the conducting wire 20 spirally from the one end 201a side of the coil part 25 in the axial direction toward the center of the coil part 25 in the axial direction, and the coil part 25 in the axial direction. It is formed by spirally winding from the other end 201b side toward the center of the coil portion 25 in the axial direction.

  One lead-out portion 202 and the other lead-out portion 203 of the conducting wire 20 are straight without any step, and extend substantially parallel to the mounting surface 101 and the opposing surface 102 of the molded body 10. One drawer portion 202 is exposed from the side surface 106 of the molded body 10, and the other drawer portion 203 is exposed from the side surface 110 of the molded body 10. The exposed positions of the one lead portion 202 and the other lead portion 203 of the conducting wire 20 are the center portions of the side surfaces 106 and 110 in the height direction.

  Then, the manufacturing method of the coil component C which has said structure is demonstrated. For convenience of explanation, a layer located in the radial direction (Y direction shown in FIG. 2B) in FIG. 2B and FIG. 3 in the coil portion 25 is defined as an inner peripheral layer. A layer overlapping in the radial direction will be described as an outer peripheral layer. Further, the layer located on the one end 201a side of the coil portion 25, that is, the lowest layer in the axial direction in FIGS. 2B and 3 is defined as the first stage, and the other end 201b side of the coil portion 25, that is, FIG. 3), the layer located on the uppermost side in the axial direction is assumed to be the third level, and the layer located between the first level and the third level is assumed to be the second level.

  When winding the conducting wire 20, about 1/3 of the total length of the conducting wire 20 required is wound from the drum to the reel. At this time, the conducting wire 20 is wound around a reel without being cut. And as shown in FIG. 3, the coil part 25 is obtained by carrying out alpha winding of the conducting wire 20. As shown in FIG.

  More specifically, first, the conductive wire 20 remaining on the drum is started to be wound from a portion a shown in FIG. 3, that is, a portion that becomes the second inner peripheral layer of the coil portion 25. The conductive wire 20 is wound for one turn to form a second inner peripheral layer of the coil portion 25, and then the conductive wire 20 is wound for one turn so as to overlap this portion in the axial direction. Thereby, the part used as the 1st inner peripheral layer of the coil part 25 is formed. Next, the conducting wire 20 is wound by one turn so as to overlap the portion that becomes the first inner peripheral layer in the radial direction, and the portion that becomes the first outer peripheral layer of the coil portion 25 is formed. Next, the conductive wire 20 is wound by one turn so as to overlap the portion that becomes the first outer peripheral layer in the axial direction and overlap the portion that becomes the second inner peripheral layer in the radial direction, A portion to be the second outer peripheral layer is formed. After forming the second outer peripheral layer, the conductor 20 is separated from the drum, leaving a predetermined length. Here, the predetermined length is a length sufficient to expose the conductor 20 from the molded body 10. The first stage inner circumferential layer, the first stage outer circumferential layer, the second stage inner circumferential layer, and the second stage outer circumferential layer have the same winding direction of the conducting wire 20, and more specifically, When viewed from the other end 201b of the coil portion 25, it is clockwise.

  As described above, in this embodiment, starting from the portion a shown in FIG. 3, the conductive wire 20 remaining on the drum is wound, and the second inner peripheral layer of the coil portion 25, the first inner peripheral layer, After sequentially forming the first-stage outer peripheral layer, the conductive wire 20 is spirally wound from one end 201a of the coil portion 25 in the axial direction toward the central portion of the coil portion 25 in the axial direction. And after forming the 2nd step | paragraph outer periphery layer of the coil part 25, the conducting wire 20 is cut off from a drum. Therefore, it is possible to smoothly draw out one lead portion 202 of the conductive wire 20 from the central portion in the height direction of the coil portion 25.

  Next, the conducting wire 20 wound around the reel is wound. First, the conductive wire 20 is wound by one turn so as to overlap the portion of the coil portion 25 that becomes the second inner peripheral layer in the axial direction, and the portion of the coil portion 25 that becomes the third inner peripheral layer is formed. At this time, the winding direction of the conducting wire 20 is opposite to the second inner circumferential layer, and more specifically, it is counterclockwise when viewed from the other end 201b of the coil portion 25. Next, the conductive wire 20 is wound for one turn so as to overlap the portion of the coil portion 25 that becomes the third inner peripheral layer in the radial direction, and the portion of the coil portion 25 that becomes the third outer peripheral layer is formed. The winding direction of the conducting wire 20 at this time is the same as that of the third inner circumferential layer of the coil portion 25.

  After forming the third outer peripheral layer, the conductive wire 20 is spirally turned about 1/4 turn from the other end 201b of the coil portion 25 in the axial direction toward the center of the coil portion 25 in the axial direction. Make a minute turn. The winding direction of the conducting wire 20 at this time is the same as that of the third inner circumferential layer of the coil portion 25. After winding, the conductor 20 is separated from the reel leaving a predetermined length. Thereby, the outer peripheral part of the coil part 25 is completed.

  As described above, in the present embodiment, the conductive wire 20 wound around the reel is wound to form the third inner peripheral layer and the outer peripheral layer of the coil portion 25, and then the other end of the coil portion 25 in the axial direction. The coil is spirally wound from 201b toward the center of the coil portion 25 in the axial direction and separated from the reel. Therefore, the other lead portion 203 of the conductive wire 20 can be smoothly drawn from between the second and third steps of the coil portion 25.

  The coil part 25 is completed through the above process.

  After the coil part 25 is formed, a rotating grindstone is applied to the lead parts 202 and 203 to peel off the covering of the lead parts 202 and 203. After the coating is peeled off, the lead wire 20 is put into the mold, and the coil portion 25 is embedded in the magnetic powder to perform pressure molding. Thereby, the molded object 10 which included the coil part 25 is made. From the molded body 10, the ends of one lead portion 202 and the other lead portion 203 of the conducting wire 20 are exposed.

  Subsequently, the molded body 10 is taken out from the mold, and the terminal fittings 30 and 32 are attached to the positions shown in FIG. And the junction part 302 of the terminal metal fitting 30 and one drawer | drawing-out part 202 of the conducting wire 20 are arc-welded, and the fusion | melting part 302a is formed. Similarly, a joint portion (not shown) of the terminal fitting 32 and the other lead portion 203 of the conductor 20 are arc welded. Thereby, the coil component C is completed.

  As described above, according to the coil component C of the present embodiment, the coil portion 25 is formed by winding the conducting wire 20 with alpha, so that the lead-out portions 202 and 203 of the conducting wire 20 are easily pulled out from the outer periphery of the coil portion 25. be able to. The pair of winding ends of the coil portion 25 is an outer peripheral portion of the coil portion 25 and is located in the central portion of the coil portion 25 in the axial direction, and the drawing portion 202, along the radial direction of the coil portion 25 from these winding ends. Since each 203 is pulled out, it is possible to smoothly pull out the leading portions 202 and 203 from the central portion of the coil portion 25 in the axial direction.

  Therefore, when the coil part 25 is arrange | positioned in the approximate center of the molded object 10, the drawer | drawing-out parts 202 and 203 can be exposed from the center part of the height direction of the molded object 10 without bending. Thereby, damage of the conducting wire 20 by bending can be prevented. Further, since it is not necessary to bend the conducting wire 20, the folded part is not covered with the molded body 10, and the coil component C can be downsized. Further, since the drawing positions of the drawing portions 202 and 203 are located in the central portion of the coil portion 25 in the axial direction, even when the coil component C is reduced in height, the thickness of the molded body 10 around the drawing position is sufficiently secured. can do. Therefore, generation | occurrence | production of the crack in the molded object 10 can be prevented. Therefore, the coil component C of the present embodiment is less likely to be cracked in the molded body 10, less likely to be damaged in the conductive wire 20 in the molded body 10, and small in size.

  In the coil component C of the present embodiment, a round wire is used as the conducting wire 20. By using a round wire, even if it is wound in multiple layers in the axial direction, twisting hardly occurs and smooth winding becomes possible. Therefore, it is possible to easily realize an increase in inductance value by increasing the number of turns.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this.

  For example, the shape of the coil part 25 is not restricted to the thing of the said embodiment.

  For example, FIG. 4A is a plan view showing a modification of the coil portion 25, and FIG. 4B is a cross-sectional view showing a modification of the coil portion 25. As shown in FIG. 4, the coil portion 25 may be formed by winding more conductive wires 20 in the radial direction. In addition, arrow D1 shown in FIG.4 (b) shows the order at the time of winding the conducting wire 20 which remained on the drum, and arrow D2 shows the order at the time of winding the conducting wire 20 wound up by the reel. . When wound in the order of the arrows D1 and D, the one lead portion 202 and the other lead portion 203 of the conducting wire 20 can be smoothly drawn out from the central portion of the coil portion 25 in the axial direction.

  5A is a plan view showing another modification of the coil portion 25, and FIG. 5B is a cross-sectional view showing another modification of the coil portion 25. As shown in FIG. 5, the coil portion 25 may be formed by winding more of the conducting wire 20 not only in the radial direction but also in the axial direction. An arrow D3 shown in FIG. 5B indicates the order when winding the conductive wire 20 remaining on the drum, and an arrow D4 indicates the order when winding the conductive wire 20 wound on the reel. Even when wound in the order of the arrows D3 and D4, the one lead portion 202 and the other lead portion 203 of the conducting wire 20 can be smoothly drawn out from the central portion of the coil portion 25 in the axial direction.

  Further, the winding of the conductive wire 20 may be started from a portion which becomes the inner peripheral portion of the coil portion 25 and which is the one end 201a or the other end in the axial direction. However, in this case, as shown in FIG. 6, when the number of turns in the radial direction increases, one lead portion 202 and the other lead portion 203 (in the case of FIG. 6, one lead portion 202 in FIG. 6) of the conducting wire 20 It becomes difficult to pull out smoothly from the central part in the axial direction of 25.

  Moreover, the conducting wire 20 may be a square wire having a substantially square cross section. In this case, although winding is somewhat difficult as compared with the round wire, the gap between the conducting wire 20 and the conducting wire 20 at the time of winding is reduced, so that the occupation ratio of the coil portion 25 in the molded body 10 is increased. Can do. Therefore, the direct current resistance of the coil component can be lowered.

It is a perspective view showing one embodiment of a coil component concerning the present invention. It is the top view and sectional drawing of a coil part with which the coil components shown in FIG. 1 are provided. It is a figure for demonstrating the winding state of the coil part shown in FIG. It is the top view and sectional drawing which show the modification of the coil part shown in FIG. It is the top view and sectional drawing which show the other modification of the coil part shown in FIG. It is sectional drawing which shows the other modification of the coil part shown in FIG.

Explanation of symbols

  C: Coil parts, 10: Molded body, 20: Conductive wire, 101: Mounting surface, 102: Opposing surface, 104-106, 108-110 ... Side surface, 25 ... Coil portion, 202 ... One lead-out portion, 203 ... Other Drawer part.

Claims (3)

A molded body that includes a magnetic material and is formed by compacting;
A conducting wire having a coil portion disposed inside the molded body and formed by alpha winding; and a pair of lead portions drawn from the coil portion;
With
In the coil portion, the conductive wire is wound so as to have a plurality of layers in a radial direction and an axial direction,
The inner peripheral portion of the coil portion is formed by winding the conductive wire in the axial direction for three or more turns,
A pair of winding ends of the coil portion is an outer peripheral portion of the coil portion and is located in a central portion of the coil portion in the axial direction, and extends from the pair of winding ends along the radial direction of the coil portion. The coil component, wherein the pair of drawer portions are respectively drawn out.   The coil component according to claim 1, wherein a cross section of the conducting wire is circular.   The said coil part is formed by starting to wind the said conducting wire from the part used as the said inner peripheral part of the said coil part, and the center part of the said coil part in the said axial direction. Coil parts.

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