JP2007200926A - Coil part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coil part which can maintain bonding strength of electrodes and can be easily manufactured. <P>SOLUTION: A background electrode 9 is formed on the external periphery of the entire peripheral surface of each of flanges 5 provided on both ends of a winding core 2, and background electrodes 11A, 11B and a notch 13 are formed on the further external periphery of the background electrode 9 of the external periphery of the peripheral surface. The height in a z-axis direction of the notch 13 is almost the same as the thickness in the z-axis direction of an end 3A of a conductor 3, and the width in a y-axis direction is almost the same as the width in the y-axis direction of the end 3A. Since the end 3A of the conductor 3 is electrically connected to the notch 13, the winding core 2 side of the notch 13 is substantially closed, and upper surfaces 11C, 11D of a background electrode 11 and an upper surface 3B of the end 3A are on substantially the same plane. This configuration can prevent a resin 15 from flowing to the end side and adhering. Thus, a deburring work can be reduced or omitted while maintaining the joining strength between the background electrodes 9, 11A, 11B and a terminal electrode 17, and a manufacturing time of the coil part 1 can be shortened. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a coil component in which a lead wire of a winding core is covered with a resin.

  In a coil component that includes a core including a core, a pair of flanges provided at both ends of the core, and a conductor wound around the core, both ends of the conductor are It is electrically connected to the base electrode provided on the peripheral surface, and the lead wire of the core is covered with resin. A terminal electrode is provided on the outer peripheral portion of the base electrode. In such a conventional coil component, the resin covering the conductor of the winding core is formed by injecting the resin into the mold using a mold that surrounds the entire coil component, and curing the resin. It covers from the core side to the end surface on the non-winding side. In this case, resin is interposed between the base electrode and the terminal electrode, and the bonding strength between the base electrode and the terminal electrode is structurally insufficient.

Therefore, in order to increase the bonding strength by directly bonding the base electrode and the terminal electrode, the protrusion on the peripheral surface of the flange extends toward the end opposite to the core of the flange, and the core side from the protrusion There is an example in which a groove is provided on the surface of the collar surface in order to form a missing portion that exposes the base region in the region (see, for example, Patent Document 1).
JP 2001-155937 A

  However, if a groove is provided on the peripheral surface of the collar as described above, the resin will flow from the gap penetrating from the core side to the non-core side when high pressure is applied to the core and the conductor when filling the mold with resin. May leak and adhere to the end of the flange opposite to the winding core. As described above, when the leaked resin adheres as a burr to the end portion on the side opposite to the winding core of the flange portion, there is a problem that it is difficult to remove and the production cannot be performed efficiently.

  Therefore, the present invention simplifies the deburring process by preventing the resin from leaking and adhering to the end of the coil component, and can be efficiently manufactured without reducing the bonding strength between the base electrode and the terminal electrode. An object of the present invention is to provide a simple coil component.

  In order to achieve the above object, the present invention provides a core including a core part and a pair of flange parts each having a peripheral surface provided at both ends of the core part, and at least the peripheral surface of each flange part A coil component comprising an electrode provided on a part, a conductive wire wound around a core part and having an end electrically connected to the electrode, and a resin covering the conductive wire of the core part, A recess or notch that opens to the core side when viewed in the axial direction of the core is formed only on one part of the peripheral surface, and the end of the conductor is electrically connected to the electrode in the recess or notch. The outer surface on the side opposite to the electrode at the end of the conducting wire in the recess or notch provides a coil component that is substantially flush with the outer surface of the electrode excluding the recess and notch.

  According to the above configuration, the lead wire end portion is connected to the electrode at the recess or notch, and thus a convex portion protruding from the outer surface of the electrode other than the recess or notch is formed by connecting the lead wire end portion to the electrode. It will not be done. Therefore, even if a process such as plating in which parts are rubbed with each other is performed, the end portion of the conducting wire is not damaged. Further, the electrode outer surface other than the recess or notch and the outer surface on the counter electrode side of the conductive wire end in the recess or notch are substantially on the same plane. Therefore, the gap between the mold arranged so as to come into contact with the outer surface of the electrode and the collar portion when filling the resin can be reduced, and the resin is less likely to leak out toward the collar peripheral surface and the axial end portion. As a result, the work of removing burrs caused by the leaked resin is reduced, and the presence of resin in the joint between the electrode and the electrode formed on the outer periphery thereof is reduced, and the bonding strength between the two electrodes is increased. It becomes possible to increase.

  Here, the recess or notch is preferably formed so as to penetrate from the core side of the electrode to the counter-winding side. Even in such a configuration, the lead wire end portion is disposed on the core side of the recess or notch, and leakage of the resin is suppressed.

  As described above, the coil that can be efficiently manufactured without reducing the bonding strength between the base electrode and the terminal electrode by suppressing the resin from leaking and adhering to the end of the coil part and simplifying the deburring process. Parts can be provided.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1 and the like, the coil component 1 according to the present embodiment includes a core 4 (FIG. 3) having a pair of flange portions 5, 5 at both ends of a cylindrical core portion 2, and the core portion 2. And the conductive wire 3 of the core 2 is covered with a resin 15. The core 4 is formed, for example, by compressing or sintering a magnetic powder such as ferrite. As the resin 15, a resin containing ferrite or the like is used.

  Here, the axial direction of the core part 2 is the x-axis, the longitudinal direction of the paper surface of FIG. 1 is the z-axis, and the direction perpendicular to the x-axis and the z-axis is the y-axis. Since the pair of flanges 5 and 5 has a point-contrast configuration with respect to the center of the core 2, one will be described below and the other will be omitted.

  As shown in FIGS. 1 to 3, the flange portion 5 has a rectangular parallelepiped shape, and as shown in FIG. 3, the peripheral surfaces 5A, 5B, 5C, and 5D, the anti-winding side end surface 5E, and the winding side end surface 5F. And have. The core part 2 is connected to the core side end face 5F. A base electrode 9 is provided on the entire surface of the peripheral surfaces 5A, 5B, 5C, 5D, and 5E.

  As shown in FIG. 1, on the outer peripheral side of the base electrode 9 on the peripheral surface 5A (FIG. 3), base electrodes 11A and 11B are provided side by side on both sides in the y-axis direction so as to form a notch 13 at the center. ing. The ends 3 </ b> A and 3 </ b> A forming one end and the other end of the conducting wire 3 are connected to each other by being electrically connected to the notch 13.

  The outer peripheral side of the end portion 3A of the conducting wire 3 disposed in the notch 13 forms a planar outer surface 3B (FIG. 2), and the outer surfaces 11C and 11D of the base electrodes 11A and 11B are the outer surface 3B of the conducting wire end portion. And substantially the same plane. The base electrodes 11A and 11B have substantially the same width in the x-axis direction as that of the peripheral surface 5A, and the height in the z-axis direction is substantially the same as the thickness in the z-axis direction of the end portion 3A of the conducting wire 3. The notch 13 has a width in the y-axis direction that is substantially the same as the width of the end 3A of the conducting wire 3, and is formed from the core 2 side in the x-axis direction to the counter-winding side. The base electrodes 9, 11A, 11B are formed of, for example, baked silver.

  Terminal electrodes 17 are provided on the outer peripheral side of the base electrodes 11A and 11B, the outer surfaces 11C and 11D of the base electrodes 11B, the outer surface 3B of the conductive wire end, and the base electrodes 9 formed on the outer peripheral portions of the peripheral surfaces 5B, 5C and 5D. Yes. The terminal electrode 17 may be composed of a plurality of layers such as two layers, for example, and is composed of an intermediate layer of silver paste and an outer layer formed by plating such as nickel-tin (Ni-Sn).

  Next, a method for manufacturing the coil component 1 according to the present embodiment will be described with reference to FIGS. First, as shown in FIGS. 3 to 5, base electrodes 9, 11 </ b> A, and 11 </ b> B are formed on the flange portion 5 of the core 4. As shown in FIG. 4, first, in order to form the base electrode 9, a silver (Ag) paste is applied over the entire peripheral surfaces 5 </ b> A, 5 </ b> B, 5 </ b> C, 5 </ b> D, and 5 </ b> E of the flange 5 and dried. At this time, the Ag paste is first applied to one collar part 5 and dried, and then the Ag paste is applied to the other collar part and dried.

  Subsequently, as shown in FIG. 5, a notch penetrating from the core 2 side in the x-axis direction to the counter-winding core side, for example, in the center in the y-axis direction on the outer peripheral side of the base electrode 9 formed on the outer peripheral portion of the peripheral surface 5A. In order to form the base electrodes 11A and 11B so as to form 13, Ag paste is applied and dried. Thereafter, when baking is performed, the base electrodes 9, 11A, and 11B are formed. When viewed from the normal direction of the outer peripheral surfaces of the base electrodes 11A and 11B, the base electrodes 11A and 11A are formed on both sides with the notch 13 interposed therebetween as shown in FIG. 11B is formed.

  Next, as shown in FIG. 7, the conducting wire 3 is wound around the core part 2 of the core 4, and both end parts 3A are arranged in the notch 13, and are electrically connected by, for example, ultrasonic welding or thermocompression bonding. To do. At this time, the depth in the z-axis direction of the notch 13 is substantially the same as the thickness in the z-axis direction of the end portion 3A of the conducting wire 3, and the width in the y-axis direction is substantially the same as the width of the end portion 3A of the conducting wire 3. Is formed. For this reason, when the end portion 3A of the conducting wire 3 is arranged in the notch 13, the x-axis direction core 2 side in the notch 13 is substantially closed by the end portion 3A.

  Next, as shown in FIG. 8, the components in a state in which the conducting wire 3 is wound are placed in molds 20A, 20B, 20C, and 20D (hereinafter collectively referred to as “mold 20”). At this time, the mold 20A does not appear in the cross-sectional view of FIG. 8, but is in contact with the outer surfaces 11C and 11D of the base electrodes 11A and 11B and the outer surface 3B of the end portion of the conducting wire at the surface 20E. As shown in FIG. 8, the molds 20 </ b> B and 20 </ b> D are respectively in contact with the base electrode 9 </ b> E formed on the outer periphery of the opposite end side surface 5 </ b> E (FIG. 3) of both flange portions 5. . The mold 20 </ b> C is in contact with the base electrode 9 </ b> C formed on the outer peripheral portion of the peripheral surface 5 </ b> C of the both flange portions 5. Then, a resin 15 is formed by filling a resin in a space generated between the conductive wire 3 wound around the core 2 and the mold 20A or 20C. In addition, although it showed in figure that the conducting wire 3 was wound by single, normally, it is wound by multiple.

  Further, a coil component is taken out from the mold 20 and a deburring process is performed on the resin adhering to the base electrodes 11A and 11B and the portions other than the conducting wire 3 of the core 2. After that, a conductive paste is applied to a predetermined thickness on the outer surfaces 11C and 11D, the outer surface 3B of the conductor end 3A, and the peripheral surfaces 5B, 5C, and 5D of the flange 5 on the outer peripheral side of the base electrode 9 and having a predetermined thickness. The terminal electrode 17 is formed through thermosetting and a plating process. The coil component 1 according to the present embodiment is completed through the above steps.

  As described above, in the coil component 1 according to the present embodiment, the notches 13 are formed in the base electrodes 11A and 11B. This notch 13 is formed only on the outer surface of the circumferential surface 5 </ b> A (FIG. 3) of the flange portion 5. As described above, the height of the notch 13 in the z-axis direction is substantially equal to the thickness of the end portion 3A of the conducting wire 3 in the z-axis direction, and the width in the y-axis direction is equal to the width of the end portion 3A in the y-axis direction. Almost equal. Further, the end 3 </ b> A of the conducting wire 3 is disposed in the notch 13 and is electrically connected thereto. For this reason, the core 2 side of the notch 13 is substantially closed, and the upper surfaces 11C and 11D of the base electrodes 11A and 11B and the upper surface 3B of the end portion 3A are substantially on the same plane.

  Therefore, when the mold 20 is disposed, the notch 13 penetrates from the core side of the flange part 5 to the counter-winding side, but from the core side of the flange part 5 to the counter-winding side end face 5E. The gap penetrating to the side can be reduced, and the resin 15 can be prevented from flowing out and adhering to the end face 5E side. As a result, it is possible to reduce or eliminate the deburring work, shorten the manufacturing time, and prevent the resin 15 from interposing between the base electrodes 9, 11A, 11B and the terminal electrode 17, The bonding strength of the electrode can be increased.

  Since the notch 13 is formed by using an electrode that can be formed by applying and drying a paste, the notch 13 can be easily formed according to the shape of the conductor end portion 3A, and other shapes and arrangements can be made. Is also possible easily. Further, for example, it is easy to connect the conductor 3 by forming notches in different peripheral surfaces of the two flanges 5 such as the peripheral surface 5A on one flange 5 and the peripheral surface 5B on the other flange 5. It is. Further, as described above, the end portion 3A of the conducting wire 3 is disposed in the notch 13 and does not form a protruding portion that protrudes from the outer surface of the base electrodes 11A and 11B. Even when a simple process is performed, the end 3A is not damaged. The base electrodes 9, 11A and 11B correspond to the electrodes of the present invention.

  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, the shape of the base electrode is not limited to the shape of the present embodiment, and the base electrode 9 may be formed only on the peripheral surface 5A as shown in FIG. The base electrodes 11A and 11B are formed only on the base electrode 9 on the outer peripheral portion of the peripheral surface 5A, as in the first embodiment. Subsequent manufacturing procedures and other configurations are the same as those in the first embodiment. According to such a configuration, in addition to the effects of the first embodiment, the manufacturing process of the base electrode 9 can be simplified.

  Moreover, although the core part 2 was made into the column shape, other shapes, such as a square pillar shape, may be sufficient. Although the collar part 5 was made into the rectangular parallelepiped shape, other shapes, such as the shape which cut off the vertex part whose cross section is a rectangle, the shape which cut off the four corners of a circle, may be sufficient, for example.

  The cross-sectional shape of the end 3A of the conducting wire 3 is preferably close to a rectangle, but the cross-section of the conducting wire 3 other than the end 3A may be other shapes such as a circle. In addition, the base electrodes 9, 11A, and 11B are formed separately in the above embodiment, but may be formed integrally. Further, the materials and forming methods of the base electrodes 9, 11A, 11B and the terminal electrode 17 are not limited to the above, and other materials and forming methods may be used.

  Although the notch 13 has penetrated from the core side in the x-axis direction to the non-winding core side in the above embodiment, it is not limited to this, and it is sufficient that the notch 13 is opened to the core side. It does not have to open to the side, and does not have to penetrate from the core side to the non-core side in the x-axis direction.

  The coil component of the present invention can be used as a coil component mounted on a circuit board.

1 is a schematic perspective view of a coil component according to an embodiment of the present invention. The fragmentary sectional view in alignment with the II-II line of FIG. The perspective view which shows the structure of the core of the coil components by embodiment of this invention. The perspective view which shows the state which formed the base electrode in the core of the coil components by embodiment of this invention. The perspective view which shows the state which formed the base electrode in the core of the coil components by embodiment of this invention. The top view which shows the state in which the base electrode was formed in the core of the coil components by embodiment of this invention. The top view which shows the state which wound the conducting wire around the core of the coil components by embodiment of this invention. Sectional drawing cut | disconnected along VIII-VIII of FIG. 7 in the state which has arrange | positioned the core which wound conducting wire in the metal mold | die, in order to form resin of the coil components by embodiment of this invention. The general-view perspective view which shows the structure of the modification of the base electrode of the coil components by embodiment of this invention.

Explanation of symbols

1: Coil parts 2: Winding core
3: Conductor
3A: end
4: Core
5: Buttocks
5A, 5B, 5C, 5D: peripheral surface
5E: End surface on the side opposite the winding core
9, 11A, 11B: Base electrode
13: Notch
15: Resin
17: Terminal electrode

Claims (2)

A core provided with a core part, and a pair of flange parts each having a peripheral surface provided at both ends of the core part;
An electrode provided on at least a part of the peripheral surface of each of the flanges;
A conducting wire wound around the winding core and having an end electrically connected to the electrode;
A resin covering the conductive wire of the winding core part;
A coil component comprising:
A recess or notch that opens to the core side when viewed in the axial direction of the core portion is formed only at one location on a part of the peripheral surface, and the end of the conducting wire is formed in the recess or the Electrically connected to the electrode at the notch,
The coil component, wherein an outer surface on the side opposite to the electrode at the end of the conductor in the recess or in the notch is substantially flush with an outer surface of the electrode excluding the recess and the notch.   2. The coil component according to claim 1, wherein the recess or the notch is formed so as to penetrate from the core side to the counter-winding side of the electrode.

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