JP6086018B2 - Coil parts - Google Patents

Description

  The present invention relates to a coil component.

  Conventionally, a coil component formed by winding a wire around a drum core is known. The drum core has a core part and flanges provided at both ends thereof. A wire with an insulation coating is wound around the core. A plurality of electrodes are provided on each of the pair of collars, and the ends of the wires are electrically connected to the respective electrodes to be connected. Such a coil component is described in, for example, Japanese Patent Application Laid-Open No. 2011-253889 (Patent Document 1). In the coil component disclosed in Patent Document 1, the electrode has an end surface electrode portion provided on the end surface of the flange portion in the axial direction of the core portion, and when the coil component is mounted on the mounting substrate. A solder fillet (hereinafter also simply referred to as a fillet) is formed on the end face electrode portion.

JP 2011-253889 A

  In recent years, there has been an increasing demand for improvement in mounting strength when a coil component is mounted on a mounting substrate, and the above-described fillet contributes to improvement in the mounting strength. Therefore, it is conceivable to form a fillet over a wider range by enlarging the end face electrode portion.

  However, the solder does not sufficiently rise at the connecting portion where the electrode and the wire are connected, and fillet formation is inhibited at this connecting portion. For this reason, when the end face electrode portion is enlarged, it is difficult to expand the fillet formation range to some extent, and it is difficult to further improve the mounting strength.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a coil component with improved mounting strength.

  A coil component according to the present invention is provided on a drum core having a winding core portion and a pair of flange portions provided at both ends of the winding core portion, a wire wound around the winding core portion, and each flange portion. A terminal electrode electrically connected to the end of the wire, each flange of the drum core can be opposed to the mounting substrate, and the mounting surface provided with the recess and the axis of the core An end surface that intersects and a mounting surface and a pair of side surfaces that intersect the end surface, and a terminal electrode is provided on the mounting surface, provided on the end surface, and coupled to the mounting portion Provided on at least one side surface of a pair of side surfaces and a connecting portion connected to the mounting portion and electrically connected to the end portion of the wire, and provided on the end surface portion and the concave portion of the mounting surface And a side portion connected to the connecting portion.

  In this coil component, when mounting on a mounting substrate, a fillet can be formed on the side surface portion of the terminal electrode provided on the side surface of the flange portion. Thereby, the formation range of the fillet is significantly expanded, and the mounting strength is improved.

  Further, the side surface of the flange portion is formed with an inclined surface inclined so that the normal direction thereof faces the mounting substrate side, and the side surface portion of the terminal electrode may be formed on the inclined surface. Good. In this case, even when the side surface portion is provided, a situation in which the outer dimensions and mounting area of the coil component are increased is suppressed.

  Furthermore, the aspect provided with the side part of a terminal electrode on the side surface in the diagonal positional relationship of a pair of collar part may be sufficient. In this case, stress is applied to the fillet formed on the side surface with a good balance.

  The side surface portion may be separated from the end surface portion without being directly connected.

  According to the present invention, a coil component having improved mounting strength is provided.

FIG. 1 is a schematic perspective view showing a coil component according to an embodiment of the present invention. FIG. 2 is a plan view of the drum core of FIG. FIG. 3 is an end view of the drum core of FIG. FIG. 4 is a side view of the drum core of FIG. FIG. 5 is a bottom view of the drum core of FIG. FIG. 6 is a bottom view of the coil component of FIG. FIG. 7 is a side view showing the coil component at the time of mounting. FIG. 8 is an end view showing the coil component at the time of mounting.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  A coil component 1 according to an embodiment of the present invention will be described with reference to FIGS. The coil component 1 according to the present embodiment is a small common mode filter. As shown in FIG. 1, the coil component 1 includes a drum core 10 and a plate-like core 20 disposed so as to cover the drum core 10.

  As shown in FIGS. 2 to 4, the drum core 10 includes a core portion 11 having a substantially rectangular cross section orthogonal to the longitudinal direction, and a pair of identical shapes provided at both ends in the longitudinal direction of the core portion 11. It has the collar parts 12 and 12.

  Four wires 30 are wound around the core part 11. Since the flanges 12 and 12 located at both ends of the drum core 10 have the same shape, only one flange 12 will be described below unless otherwise specified. In addition, a longitudinal direction that is a direction in which the axis of the core part 11 is oriented is defined as an X-axis direction, and a substantially rectangular longitudinal direction that is a cross-sectional shape orthogonal to the longitudinal direction of the core part 11 is defined as a Y-axis direction. The direction orthogonal to the X-axis direction and the Y-axis direction will be described as the Z-axis direction. Furthermore, the direction from substantially lower right to substantially upper left in FIG. 1 is defined as the X axis + direction, and the opposite direction is defined as the X axis−direction. In addition, a direction from approximately upper right to approximately lower left in FIG. 1 is defined as a Y-axis + direction, and the opposite direction is defined as a Y-axis-direction. Also, the direction from the bottom to the top of FIG. 1 is defined as the Z-axis + direction, and the opposite direction is defined as the Z-axis-direction. As an example, the dimension of the drum core 10 in the X-axis direction is 3.36 mm, the dimension of the drum core 10 in the Y-axis direction is 2.66 mm, and the dimension of the drum core 10 in the Z-axis direction is 1.45 mm.

  The flange portions 12 are provided integrally with the core portion 11 at both ends of the core portion 11 in the X-axis direction. The flange 12 has a substantially rectangular parallelepiped shape, and has six surfaces including an upper end surface 12A, a mounting surface 12B, a first side surface 12C, a second side surface 12D, an outer end surface 12E, and an inner end surface 12F.

  The upper end surface 12A and the mounting surface 12B have a parallel positional relationship and a positional relationship parallel to the XY plane. The upper end surface 12 </ b> A is a surface that faces a plate-like core 20 described later, and is a surface that is fixed to the plate-like core 20. The mounting surface 12B is a surface facing a mounting substrate 50 described later.

  The first side surface 12C and the second side surface 12D have a parallel positional relationship and a positional relationship parallel to the XZ plane. Further, the outer end surface 12E and the inner end surface 12F have a parallel positional relationship and a positional relationship parallel to the YZ plane.

  Concave portions 12a are formed at both ends in the Y-axis direction of the mounting surface 12B. More specifically, the recess 12a is formed of a notch, and is a connecting portion between the first side surface 12C and the mounting surface 12B that defines the outer surface of the substantially rectangular parallelepiped, from the outer end surface 12E to the inner end surface 12F, and the second side surface. The connection portions between 12D and the mounting surface 12B are cut out. That is, the corners of both ends of one side of the rectangular portion corresponding to the mounting surface 12B of the flange portion 12 whose cross section (YZ cross section) cut along a plane orthogonal to the axial direction of the core portion 11 forms a substantially rectangular shape are cut out. It has a shape as if it were.

  Of the pair of side surfaces 12C and 12D, the first side surface 12C is shaped such that the lower side (that is, the mounting surface 12B side) is cut out, and an inclined surface 12b is formed. The inclined surface 12b is inclined so that the normal direction thereof faces downward (a mounting substrate 50 side described later). For example, the inclined surface 12b has an inclination angle of about 10 degrees and a height of about 2/3 of the height of the side surface 12C. Note that such an inclined surface 12b is not formed on the second side surface 12D.

  Each of the wires 30 is made of a copper wire that is covered with insulation, and four wires 30 are wound around the core portion 11. The diameter of each wire 30 is, for example, 0.14 mm. The wire 30 is a part of the core part 11 and is drawn out from the vicinity of the connection part connected to the flange part 12, and extends toward the concave part 12a. One end portion and the other end portion of the wire 30 are disposed in the vicinity of a total of four recesses 12a, and are electrically connected to terminal electrodes 41 and 42 (to be described later) by thermocompression bonding in the recesses 12a.

  Terminal electrodes 41 and 42 are provided on the flange 12, respectively. Each of the terminal electrode 41 and the terminal electrode 42 is formed by plating using an Ag layer obtained by printing and baking an Ag paste as an underlayer, and includes, for example, an intermediate Ni plating layer and an upper Sn plating layer. The thickness of the terminal electrodes 41 and 42 is, for example, about 0.03 mm.

  Since the terminal electrode 41 and the terminal electrode 42 are substantially mirror-symmetrical, only the terminal electrode 41 will be described below unless otherwise specified, and the description of the terminal electrode 42 is omitted.

  The terminal electrode 41 includes a mounting portion 41B provided on the mounting surface 12B, an end surface portion 41E provided on the outer end surface 12E, a connecting portion 41G provided in the recess 12a of the mounting surface 12B, and a side surface 12C. And a side surface portion 41C.

  The mounting portion 41B is a portion that is electrically connected to a conductive pattern on the mounting substrate 50, which will be described later, and is an area on the mounting surface 12B where the recess 12a is not formed, as shown in FIGS. (Protrusions region) is provided. More specifically, the mounting portion 41B of the terminal electrode 41 is provided on the side surface 12C side of the convex region, while the mounting portion 42B of the terminal electrode 42 is provided on the side surface 12D side of the convex region. Thus, the mounting portion 41B and the mounting portion 42B are separated by a predetermined distance.

  The end surface portion 41E is a portion connected to the mounting portion 41B, and is provided on the outer end surface 12E as shown in FIG. More specifically, the end surface portion 41E of the terminal electrode 41 extends from the mounting surface 12B to the vicinity of the upper end surface 12A in the Z direction so as to straddle the concave and convex regions of the mounting surface 12B in the Y direction. The outer end surface 12E is provided in a wide range on the side surface 12C side. On the other hand, the end surface portion 42E of the terminal electrode 42 is also mirror-symmetrical and is provided in a wide range on the side surface 12D side of the outer end surface 12E. By providing the end face portions 41E and 42E in such a wide range, there is an advantage that the medium can be satisfactorily contacted during plating, so that the plating can be easily formed. Similarly to the mounting portions 41B and 42B, the end surface portions 41E and 42E are separated from each other by a predetermined distance.

  The connecting portion 41G is a portion that is connected to the mounting portion 41B and is electrically connected to the end portion of the wire 30. As shown in FIGS. 3 and 5, the connecting portion 41G is provided so as to cover substantially the entire inner surface of the concave portion 12a of the mounting surface 12B, and continuously and integrally with the mounting portion 41B in the convex region. Is provided. As shown in FIG. 6, two end portions of the wire 30 are arranged in the connecting portion 41 </ b> G, and are electrically connected to the wire 30 by thermocompression bonding.

  As shown in FIG. 4, the side surface portion 41C is provided so as to cover the entire area of the inclined surface 12b of the side surface 12C. The side surface portion 41C is provided continuously and integrally with the connecting portion 41G so as to be connected to the connecting portion 41G. The side surface portion 41C is partially connected to an end surface portion 41E provided on the outer end surface 12E side at a lower portion thereof, but the side surface portion 41C is not directly connected to the end surface portion 41E, and the side surface portion 41C and the end surface portion 41E may be separated from each other. The terminal electrode 42 does not have a portion corresponding to the side surface portion 41C of the terminal electrode 41, and no electrode is formed on the side surface 12D.

  In addition, although illustration is abbreviate | omitted, not only the one collar part 12 mentioned above but the other collar part 12 is provided with the terminal electrode similar to the terminal electrodes 41 and 42 mentioned above. However, the shape of the one flange portion 12 and the other flange portion 12 and the arrangement of the terminal electrodes are in a point-symmetric relationship around the Z axis. Therefore, the inclined surface 12b and the side surface portion 41C of the side surface 12C described above are formed at locations on the other flange portion 12 in a diagonal positional relationship.

  The plate-shaped core 20 mounted on the drum core 10 described above has a substantially rectangular plate shape having a thickness in the Z-axis direction. The lower surface of the plate-like core 20 has a positional relationship parallel to the XY plane. In a state where the plate-like core 20 is placed on the drum core 10, the lower surface 20a and the entire upper end surface 12A of the drum core 10 are in contact with each other via an adhesive and fixed to each other.

  Next, a mode in which the above-described coil component 1 is mounted will be described with reference to FIGS. 7 and 8.

  The coil component 1 is mounted on the mounting substrate 50 by reflow. Specifically, the terminal electrodes 41 and 42 of the coil component 1 are aligned with a conductive pattern (not shown) provided on the mounting substrate 50, and the terminal electrodes 41 and 42 and the conductive pattern connect the solder 60. Through each other. At this time, as shown in FIGS. 7 and 8, solder fillets 61 and 62 are formed on the end surface portion 41 </ b> E and the side surface portion 41 </ b> C of the terminal electrode 41.

  The solder fillet 61 formed on the end surface portion 41E is formed on a part of the end surface portion 41E, specifically, in the convex region where the concave portion 12a is not formed, but the concave portion 12a in which the wire 30 is disposed. It is not formed in the part corresponding to. As shown in FIG. 7, since the solder fillet 61 extends downward along the X direction from the outer end surface 12E, particularly high mounting strength in the X direction is realized. A solder fillet 61 similar to the solder fillet 61 formed on the end surface portion 41E is also formed on the end surface portion 42E of the terminal electrode 42.

  The solder fillet 62 formed on the side surface portion 41C is formed below the side surface portion 41C. As described above, since the side surface portion 41C is formed on the inclined surface 12b, as shown in FIG. 8, a part of the solder fillet 62 is accommodated in a notch portion defined by the inclined surface 12b. The Since the solder fillet 62 extends downward from the inclined surface 12b of the side surface 12C along the Y direction, particularly high mounting strength in the Y direction is realized.

  As described above, in the coil component 1 described above, when mounted on the mounting substrate 50, the fillet 61 is formed on the end surface portion 41E provided on the outer end surface 12E, and in addition, the side surface provided on the side surface 12C. A fillet 62 is formed in the portion 41C. Therefore, compared with the prior art in which a fillet is formed only on the outer end surface 12E side, the formation range of the fillet 60 is significantly expanded, thereby realizing high mounting strength.

  In the terminal electrode 41, the solder fillet 61 formed on the end surface portion 41E mainly secures the mounting strength in the X direction, and the solder fillet 62 formed on the side surface portion 41C mainly secures the mounting strength in the Y direction. Therefore, high mounting strength can be obtained in all directions within the XY plane.

  Furthermore, in the coil component 1, since the side surface portion 41C is provided on the inclined surface 12b of the side surface 12C, the side surface portion 41C can be formed so as to fit in the outer dimensions of the coil component 1. Expansion of dimensions can be suppressed. Moreover, the expansion of the mounting area of the coil component 1 is suppressed by accommodating the fillet 62 in the notch part defined by the inclined surface 12b.

  Moreover, in the coil component 1, as described above, the side surface portion 41 </ b> C of the terminal electrode 41 is provided on the side surface 12 </ b> C that is in a diagonal positional relationship between the pair of flange portions 12 and 12. Therefore, stress is applied in a well-balanced manner to the fillet 62 formed on the side surface portion 41 </ b> C, and a situation in which troubles such as chip standing due to stress bias are generated is effectively suppressed.

  The present invention is not limited to the above-described embodiment, and various modifications can be made.

  For example, although the aspect which provided the side part 41C only in one terminal electrode 41 among the two terminal electrodes 41 and 42 provided in the collar part 12 was shown, it is provided also in the other terminal electrode 42 (provided on side 12D) A side surface portion may be provided. At that time, the side surface 12D may be provided with an inclined surface similar to the inclined surface 12b of the side surface 12C. However, when the inclined surfaces are provided on all the side surfaces (four side surfaces) of the pair of flanges 12, the volume of the drum core (core volume) is greatly reduced. It is more preferable to provide only on the two side surfaces in the positional relationship.

  Moreover, although the aspect in which the four wires 30 were wound around the drum core 10 was shown, the number of the wires 30 can be increased or decreased as appropriate.

  DESCRIPTION OF SYMBOLS 1 ... Coil components, 10 ... Drum core, 11 ... Winding core part, 12 ... Gutter part, 12A ... Upper end surface, 12B ... Mounting surface, 12C, 12D ... Side surface, 12E ... Outer end surface, 12a ... Recessed part, 12b ... Inclined surface, DESCRIPTION OF SYMBOLS 30 ... Wire, 41, 42 ... Terminal electrode, 41B, 42B ... Mounting part, 41C ... Side surface part, 41E, 42E ... End surface part, 41G, 42G ... Connection part, 50 ... Mounting board, 60, 61, 62 ... Solder Fillet.

Claims (3)

A drum core having a core part and a pair of flanges provided at both ends of the core part;
A wire wound around the core,
A terminal electrode provided on each of the flanges, to which an end of the wire is electrically connected;
Each buttocks of the drum core is
A mounting surface capable of facing the mounting substrate and provided with a recess;
An end face intersecting with the axis of the core,
A pair of side surfaces intersecting the mounting surface and the end surface;
The terminal electrode is
A mounting portion provided on the mounting surface;
An end surface portion provided on the end surface and connected to the mounting portion;
A connecting portion provided in the concave portion of the mounting surface, coupled to the mounting portion, and electrically connected to an end of the wire;
Together provided on at least one side of the pair of side surfaces, possess a side surface portion which is connected to the joint line portion,
Wherein the side portions of the terminal electrodes, that are provided on the sides in a positional relationship of the diagonal of the pair of flange portions, the coil parts.   An inclined surface that is inclined so that a normal direction thereof faces the mounting substrate is formed on the side surface of the flange portion, and the side surface portion of the terminal electrode is formed on the inclined surface. Item 2. The coil component according to Item 1. The coil component according to claim 1 or 2 , wherein the side surface portion is separated from the end surface portion without being directly connected.

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