JP2006032560A - Coil component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small coil component whose leak magnetic flux is little, which is superior in a DC superposition characteristic and in loss and whose manufacture is easy. <P>SOLUTION: The coil component 1 has a winding wire 3, a winding core 5 and a frame core 13. Thickness of the frame core 13 is made uniform and it is integrally formed. The core has a box-type shape where two confronted sides make an opening. In the wire winding 3, both ends are formed as electrodes 9 and 11. The electrodes 9 and 11 are arranged in prescribed positions of a base 15 on an opening part 14-side. The winding core 5 is disposed inside the frame core 13, and the wire winding 3 is wound to the sides. The frame core 13 and the winding core 5 are separately formed. Thickness of the frame core 13 is made uniform and a size of the coil component 1 is miniaturized. The frame core 13 is integrally formed and the electrodes 9 and 11 are arranged on the opening part 14-side. Leakage magnetic flux to outside of the coil component 1 is reduced. The component can easily be manufactured since it is integrally formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a coil component used in an electronic device or the like.

  2. Description of the Related Art Conventionally, there is a coil component that has a box-shaped core with openings provided on two opposing side surfaces (hereinafter referred to as first and second side surfaces), and a winding wound around the winding core. . Two other side surfaces (hereinafter referred to as third and fourth side surfaces) of the box-shaped core are formed to be thicker than the upper and lower surfaces. In addition, electrodes are respectively formed at the end portions of the third and fourth side surfaces corresponding to the left and right sides of the opening. The ends of the windings are connected to these electrodes with solder or the like (see, for example, Patent Document 1).

  As a second example, there is a coil component including a pair of E-type cores sandwiching a winding and a base for bonding and fixing a box-shaped core formed by joining the pair of E-type cores. Two opposite sides of the base protrude outward from the E-type core. A through hole is formed in the thickness direction of the base, a metal terminal is disposed in the through hole, and both ends of the winding are connected to the metal terminal (for example, see Patent Document 2).

As a third example, there is a coil component using a square core formed by a C-type first core and an I-type second core. The C-shaped first core is composed of a rectangular bottom plate and two side surfaces erected on two opposing sides of the bottom plate. The I-type second core has a rectangular shape that covers the upper surface of the first core. Inside the square-shaped magnetic path formed by the first and second cores, a winding core around which a winding is wound is disposed above and below via a spacer (for example, see Patent Document 3). ).
JP-A-8-306559 (page 3-4, FIG. 3) Japanese Patent Laid-Open No. 11-144973 (page 2-3, FIG. 1) Japanese Patent Laid-Open No. 9-35965 (page 3-4, FIG. 1)

  In the coil component described in Patent Document 1, the third and fourth side surfaces of the core are configured to be thicker than the upper and lower surfaces in order to provide electrodes at both ends thereof. Therefore, the core itself becomes large, which is not preferable from the viewpoint of miniaturization. In addition, since electrodes are provided in the openings provided on the third and fourth side surfaces, and magnetic flux leaks in both directions, it adversely affects the surrounding parts and deteriorates the characteristics of the coil parts. There is a fear. Furthermore, the ends of the windings and the electrodes are joined by solder or the like, and there are problems such as a risk of disconnection and an increase in resistance.

  In the coil component described in Patent Document 2, since the core is configured by combining a pair of E-type cores, it is necessary to polish the joint surface during manufacturing. There is also a problem that magnetic flux leaks from the mating surface of the core. The base is provided with a metal terminal, and there is a problem that AC copper loss increases due to the influence of leakage magnetic flux.

  Even in the coil component described in Patent Document 3, since the core is configured by combining a C-type core and an I-type core, as in the coil component described in Patent Document 2, it is necessary to polish the joint surface during manufacturing. . Further, magnetic flux leaks from the mating surface of the core. Since an iron core is used as the core and the winding core, it is not suitable for high frequency applications.

  Accordingly, an object of the present invention is to provide a coil component that can be reduced in size and easy to manufacture by preventing the deterioration of characteristics by minimizing leakage magnetic flux and AC loss.

  The coil component according to the present invention provided to achieve the above object has a box-shaped frame core, a winding, and a winding core. A box-shaped frame core is composed of a bottom plate, a top plate, and a pair of opposing side plates that connect the bottom plate and the top plate, and is a core with a cross-section in a square shape, and the thickness of each plate material is uniform The whole is integrally formed. Further, two opposing side surfaces of the box-shaped frame core are opened. Both ends of the winding function as electrodes. This electrode is disposed on one side of one opening of the frame core. The winding core is formed separately from the frame core and is disposed inside the frame core. A winding is wound around the circumferential surface of the winding core.

  Thus, since the thickness of the frame core is uniform, the outer dimension of the coil component is not unnecessarily increased, and the coil component having the minimum size can be obtained. Further, the frame core is integrally formed, and the electrodes at both ends of the winding are provided on one opening side, so that the leakage magnetic flux to the outside of the coil component is reduced.

  The coil component may further include a base. The base is provided in contact with the outside of the bottom plate and insulates the electrode and the frame core.

  Further, a dummy terminal for fixing the coil component to the substrate can be further provided.

  It is preferable that each of the upper surface facing the top plate of the winding core and the lower surface facing the bottom plate form a magnetic gap between the frame core. The magnetic gap reduces the magnetic flux density and makes it difficult to cause magnetic saturation. Further, an insulator may be interposed in the magnetic gap between at least one of the magnetic gaps formed between the upper surface of the core and the frame core and between the lower surface of the core and the frame core.

  The winding is preferably wound between the upper surface and the lower surface of the core. Such a configuration reduces the exposure of the winding to the leakage magnetic flux.

  According to the coil component of the present invention, it is small, the direct current superimposition characteristic is improved, the deterioration of the characteristic such as the alternating current loss can be reduced, the adverse effect on other adjacent parts is small, and the manufacturing is easy. It is done.

  A coil component according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2 are schematic perspective views of the coil component 1. As shown in FIGS. 1 and 2, the coil component 1 includes a winding 3, a winding core 5, a frame core 13, a base 15, a dummy terminal 17, and the like.

  3 is a cross-sectional view taken along the cutting line III-III shown in FIG. As shown in FIG. 3, the frame core 13 is disposed on the base 15, and the bottom plate 13 a of the frame core 13 is fixed to the base 15. Inside the frame core 13, a spacer 19 is disposed in contact with the bottom plate 13 a, and the core 5 is disposed on the spacer 19. A winding 3 is wound around the peripheral surface of the core 5. The winding 3 is wound within the range of the winding core 5 in the height direction, and the uppermost part of the winding 3 is located at the same or lower position as the upper surface of the winding core 5. The winding core 5 and the top plate 13c of the frame core 13 are not in contact with each other, and a gap is formed between them. The space between the upper surface of the core 5 and the top plate 13c and the portion where the spacer 19 is inserted act as a magnetic gap.

  As shown in FIG. 1, the winding 3 winds one rectangular wire a predetermined number of times, and both end portions extend in a substantially parallel direction toward the opening 14. Both end portions of the winding 3 are bent downward when exiting from the opening 14, and the bent portions are fitted into the cut portions formed in the base 15. Both end portions of the winding 3 fitted into the cut portion of the base 15 function as electrodes 9 and 11 of the coil component 1, respectively. The electrodes 9 and 11 are obtained by flattening the ends of the winding 3 and then cutting the width so as to be equal to the width of the winding 3, further peeling off the coating on the surface and covering with solder. A predetermined portion of the winding 3 and the core 5 are bonded with resin. For example, an epoxy resin can be used as the resin.

  As shown in FIG. 2, a dummy terminal 17 is provided on the base 15 on the side facing the side on which the electrodes 9 and 11 are provided. The dummy terminal 17 is a fixing terminal provided to increase mounting stability and fixing strength of the coil component 1 when the coil component 1 is mounted on the substrate. The dummy terminal 17 is made of a metal containing, for example, tin (Sn), copper (Cu), or the like. A part of the winding 3 on the dummy terminal 17 side is fixed to the bottom plate 13 a of the frame core 13 with resin.

  Hereinafter, each component will be described. As shown in FIG. 4, the winding 3 is formed of a single flat wire having a substantially rectangular cross section. This flat wire is covered with, for example, an epoxy-modified acrylic resin. Both ends of the winding 3 constitute electrodes 9 and 11. The electrodes 9 and 11 are bent at approximately two right angles before the winding 3 is incorporated into the frame core 13, and this bent portion is incorporated into the frame core 13 according to a predetermined position of the base 15. The winding 3 can be positioned.

  As shown in FIG. 5, the winding core 5 has a cylindrical shape, and is made of, for example, ferrite containing manganese (Mn) and zinc (Zn) as main components. The height from the lower surface to the upper surface of the core 5 is lower than the height inside the frame core 13, and a magnetic gap is formed between the core 5 and the frame core 13. Further, the height of the winding core 5 must be higher than the height of the winding portion of the winding 3 so that the winding 3 is wound within the range of the winding core 5 in the height direction.

  As shown in FIG. 6, the spacer 19 is, for example, a polyimide resin sheet such as Kapton tape. The portion where the spacer 19 is inserted constitutes a magnetic gap between the frame core 13 and the lower surface of the core 5. The spacer 19 is bonded to the lower surface of the core 5 with resin before the winding 3 is wound around the core 5.

  As shown in FIG. 7, the frame core 13 is a box-shaped core having a bottom plate 13a, a top plate 13c, and two side plates 13b and 13d and having two opposing side surfaces opened. The bottom plate 13a, the top plate 13c, and the two side plates 13b and 13d have a uniform thickness and are integrally formed. The frame core 13 is made of, for example, ferrite whose main component is Mn, Zn or the like.

  As shown in FIG. 8, the base 15 includes a substantially rectangular flat plate portion and an electrode fixing portion standing along one side of the flat plate portion, both of which are integrally formed of an insulating resin. Concave portions 23 and 25 for inserting and fixing the electrodes 9 and 11 of the winding 3 are formed on the outer surface of the electrode fixing portion.

  As described above, according to the coil component 1 according to the present embodiment, the thicknesses of the bottom plate 13a, the top plate 13c, and the two opposing side plates 13b and 13d of the frame core 13 are all uniform. Therefore, when compared with the coil component in which the thickness of the plate material of the specific part is thicker than the thickness of the plate material of the other part, the external dimensions of the coil component 1 according to the present embodiment are the same as the external dimensions of the coil component to be compared. If so, a wider internal space can be ensured, and if the size of the internal space is the same as the size of the internal space of the coil component to be compared, the outer dimensions can be reduced.

  Further, since the frame core 13 is integrally formed, it is not necessary to polish the joint surface, and the manufacturing can be simplified. Furthermore, since the magnetic flux does not leak from the joint portion, it does not adversely affect the surrounding components and increase the AC copper loss.

  Since both ends of the winding 3 are electrodes 9 and 11 and the winding 3 can be directly connected to the substrate, it is not affected by the leakage magnetic flux and the AC copper loss is small. In addition, it is not necessary to connect the electrode and the winding with solder or the like, the risk of disconnection is reduced, the DC resistance is small, and the DC resistance value varies little from part to part. Since the electrode 9 and the electrode 11 are disposed on the same side of the opening 14, the magnetic flux does not leak to the facing opening. Furthermore, by positioning the electrodes 9 and 11 in the recesses 23 and 25 of the base 15, the winding 3 and the core 5 can be positioned within the frame core 13. The variation of the can be reduced.

  Since the winding core 5 does not have a bonding surface, a polishing process is unnecessary and manufacturing is easy. Further, the core 5 is formed separately from the frame core 13, and it is easy to form a magnetic gap between the core 5.

  By providing a magnetic gap between the frame core 13 and the core 5, saturation of the magnetic flux density between the frame core 13 and the core 5 can be reduced. Thereby, the direct current superimposition characteristic of the coil component 1 can be improved. In particular, the DC superposition characteristics can be improved by making the distance between the two magnetic gaps formed between the upper surface and the lower surface of the core 5 between the core 5 and the frame core 13 substantially the same.

  Since the base 15 is disposed in contact with the bottom plate 13 a of the frame core 13, insulation between the electrodes 9 and 11 and the frame core 13 is possible. Moreover, since the dummy terminal 17 is provided, the mounting stability and the fixing strength of the coil component 1 on the substrate can be increased.

  In the coil component 1, the winding 3 is wound between the upper surface and the lower surface of the winding core 5 away from the magnetic gap region. Moreover, since the frame core 13 is integrally formed, magnetic flux does not leak from the joint surface. Therefore, for example, it is possible to reduce the AC resistance by the winding 3 to almost half as compared with other coil components that employ an E-type core. Moreover, since the coil | winding 3 uses the rectangular wire with a substantially rectangular cross section, since a cross-sectional area can be taken larger compared with a wire with a circular cross section, a copper loss can be lowered | hung.

  The coil component according to the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope described in the claims. For example, in the coil component 1, the base 15 has a size including the entire bottom plate 13 a of the frame core 13, but may have a size including a part of the bottom plate 13 a. Further, the base 15 is not necessarily required, and may be a coil component having a configuration in which the base 15 is not provided. When the base 15 is not provided, it is preferable to employ, for example, a ferrite having a high resistance value, for example, nickel (Ni), copper (Cu), zinc (Zn) as a main component, as the material of the frame core 13. At this time, the dummy terminal 17 can be provided in the opening on the side facing the opening 14 of the frame core 13.

  Although a sheet-like spacer 19 is used to form a magnetic gap between the lower surface of the core 5 and the frame core 13, the spacer 19 is not limited to such a sheet-like member. For example, a material in which glass beads are mixed into a resin can be used as a spacer as long as a uniform thickness is obtained and the magnetic resistance is larger than that of the frame core 13 and can act as a magnetic gap.

  The shape of the core 5 is not limited to a cylindrical shape, and may be an elliptical cross section, a substantially square column shape with curved corners, or the like. Also, if the shape of the frame core 13 is uniform and formed integrally, the connecting portions of the bottom plate 13a, the top plate 13c, and the two side plates 13b, 13d do not form a straight line but are curved. It may be a shape like this.

  In addition, the common mode filter can be configured by applying the structure of the coil component according to the present invention.

  The coil component of the present invention can be used in electronic devices such as a personal computer power supply system.

1 is a perspective view of a coil component 1 according to the present embodiment. 1 is a perspective view of a coil component 1 according to the present embodiment. 1 is a cross-sectional view of a coil component 1. 3 is a perspective view of a winding 3. FIG. 3 is a perspective view of a winding core 5. FIG. 3 is a perspective view of a spacer 19. FIG. 3 is a perspective view of a frame core 13. FIG. 3 is a perspective view of a base 15. FIG.

Explanation of symbols

1. . . 2. Coil parts . . Winding 5. . . Winding core 9,11. . . Electrode 13. . . Frame core 15. . . Base 17. . . Dummy terminal 19. . . Spacer

Claims (6)

A bottom plate having a uniform thickness, a top plate, a box-shaped frame core integrally formed with a pair of opposing side plates that connect the bottom plate and the top plate, and having a two-sided opening and a cross-sectionally box-shaped cross section;
Both ends are formed as electrodes, and the electrode is disposed on one side of the opening;
The winding core is disposed inside the frame core, the winding is wound around a peripheral surface, and a winding core formed separately from the frame core;
A coil component comprising:   The coil component according to claim 1, further comprising a base that is provided in contact with the outside of the bottom plate and insulates the electrode from the frame core.   The coil component according to claim 1, further comprising a dummy terminal for fixing the coil component to the substrate.   4. The magnetic core according to claim 1, wherein each of an upper surface facing the top plate and a lower surface facing the bottom plate of the winding core forms a magnetic gap with the frame core. 5. The coil component described.   An insulator is interposed in at least one of the magnetic gaps formed between the upper surface of the winding core and the frame core and between the lower surface of the winding core and the frame core. Item 5. The coil component according to Item 4.   The coil component according to any one of claims 1 to 5, wherein the winding is wound between an upper surface and a lower surface of the winding core.

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