Coil component and method for manufacturing the coil component

Abstract

To provide coil component which can improve coil characteristics.SOLUTION: A coil component comprises: a core which has a winding core part extending in an axial direction, and first flange part and a second flange part provided on both ends in the axial direction of the winding core part; a coil wound around the winding core part; and a top plate provided so as to straddle the first flange part and the second flange part. The first flange part has a first facing surface which faces the top plate. The top plate has a second facing surface which faces the first flange part. In a cross section perpendicular to the axial direction and intersecting the first flange part, the first facing surface is provided with a protrusion having a protruding shape which protrudes toward the top plate side, and the second facing surface is provided with a recess having a recessed shape which corresponds to the protruding shape of the protrusion of the first flange part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a coil component and a method for manufacturing a coil component. [Background technology]

[0002] A conventional coil component is described in JP 2018-152576 A (Patent Document 1). This coil component includes a core having a winding core portion extending in the axial direction and a first flange portion and a second flange portion provided at both axial ends of the winding core portion, a coil wound around the winding core portion, and a top plate provided to straddle the first flange portion and the second flange portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-152576 A Summary of the Invention [Problem to be solved by the invention]

[0004] By the way, in JP 2018-152576 A, it is described that the upper surface of the first flange portion and the upper surface of the second flange portion in the height direction of the coil component are flat surfaces. However, when the present inventors actually manufactured the core and the top plate by powder molding, they found the following problem.

[0005] It was found that because the core has a complex structure including a first flange, a second flange, and a winding core, extremely small convex portions are likely to occur on the upper surface of the first flange and the upper surface of the second flange. On the other hand, because the top plate is plate-shaped and does not have a complex structure, it was easy to make the bottom surface of the top plate flat.

[0006] Therefore, when the core and the top plate are combined to manufacture the coil component, the distance between the top surface of the first flange and the top surface of the second flange and the bottom surface of the top plate may be larger than the desired distance. As a result, it was found that the magnetic resistance of the corresponding portion increases, and the coil characteristics may deteriorate.

[0007] Therefore, an object of the present disclosure is to provide a coil component that can improve coil characteristics. [Means for solving the problem]

[0008] In order to solve the above problems, a coil component according to one aspect of the present disclosure comprises: A core having a winding core portion extending in an axial direction and a first flange portion and a second flange portion provided at both ends of the winding core portion in the axial direction; A coil wound around the winding core; A top plate provided so as to straddle the first flange portion and the second flange portion, The first flange portion has a first opposing surface that faces the top plate, the top plate has a second opposing surface opposing the first flange portion, In a cross section perpendicular to the axial direction and intersecting the first flange portion, The first opposing surface is provided with a convex portion having a convex shape that is convex toward the top plate side, The second opposing surface is provided with a recess having a concave shape corresponding to the convex shape of the convex portion of the first flange portion.

[0009] According to the above aspect, since the convex shape of the convex part provided on the first flange corresponds to the concave shape of the concave part provided on the top plate, the distance between the opposing surface on the top plate side and the opposing surface on the first flange side can be made smaller than when a core having a convex part on the top surface of the first flange is combined with a top plate having a flat bottom surface. As a result, the magnetic resistance caused by the space between the opposing surface on the top plate side and the opposing surface on the first flange side can be reduced, thereby improving the coil characteristics.

[0010] Preferably, in one embodiment of the coil component, The top plate has a top surface opposite to the second opposing surface, In the cross section, the uppermost position of the convex portion of the first flange portion is disposed in the center of the first flange portion in a direction parallel to the top surface of the top plate.

[0011] According to the above embodiment, even if the first flange portion is positioned offset relative to the top plate in a direction perpendicular to the axial direction and parallel to the top surface of the top plate, the distance between the opposing surface on the top plate side and the opposing surface on the first flange portion side can be more reliably reduced at the uppermost position of the convex portion in the direction perpendicular to the top surface of the top plate.

[0012] Preferably, in one embodiment of the coil component, The top plate has a top surface opposite to the second opposing surface, In the cross section, when the direction from the core toward the top plate is considered the upper side, (i) the uppermost position of the inner surface of the recess, (ii) the top of the convex portion, and (iii) at least one of both ends of the recess in a direction parallel to the top surface of the top plate are arranged in this order from the top plate side.

[0013] According to the embodiment, the distance between the second opposing surface and the first opposing surface can be more reliably reduced across the direction perpendicular to the axial direction and parallel to the top surface of the top plate.

[0014] Preferably, in one embodiment of the coil component, The top plate has a top surface opposite to the second opposing surface, When viewed from a direction perpendicular to the top surface of the top plate, the protrusion and the recess each have an overlapping region, In the cross section, the distance between the convex portion and the concave portion at both ends of the overlapping area in a direction parallel to the top surface of the tabletop is greater than the distance between the convex portion and the concave portion at the center of the overlapping area in a direction parallel to the top surface of the tabletop.

[0015] According to this embodiment, it is possible to more reliably reduce the distance between the second opposing surface and the first opposing surface in the center of the region that forms the overlapping portion in the direction orthogonal to the axial direction and parallel to the top surface of the top plate.

[0016] Preferably, in one embodiment of the coil component, The top plate has a top surface opposite to the second opposing surface, and a bottom surface opposite to the top surface and including the second opposing surface, The bottom surface of the top plate has a notch on at least one of both ends in a direction perpendicular to the axial direction and parallel to the top surface of the top plate.

[0017] According to the embodiment, since the top plate has a notch, when the core and the top plate are bonded with an adhesive, the adhesive can be guided and stored in the notch, and therefore, even if an excessive amount of adhesive is used, the adhesive can be prevented from spilling out of the coil component.

[0018] Preferably, in one embodiment of the coil component, In the cross section, when the direction from the core toward the top plate is considered the upper side, the top of the inner surface of the notch, the top of the inner surface of the recess, the top of the convex portion, and of both ends of the recess in a direction parallel to the top surface of the top plate, the end on the side where the notch is provided are arranged in this order from the top plate side.

[0019] According to the embodiment, the size of the cutout can be increased, and therefore a larger amount of adhesive can be guided and stored in the cutout, so that the adhesive can be more reliably prevented from spilling out of the coil component.

[0020] Preferably, in one embodiment of the coil component, When viewed from a direction perpendicular to the top surface of the top plate, the notch overlaps with the protrusion of the first flange.

[0021] According to the above embodiment, compared to a case where the cutout does not overlap with the convex portion of the first flange portion, it is possible to prevent adhesive from leaking outside the coil component from the end of the concave portion in a direction perpendicular to the axial direction and parallel to the top surface of the top plate, and it is possible to more reliably guide the adhesive to the cutout.

[0022] Preferably, in one embodiment of the coil component, The top plate has a top surface opposite to the second opposing surface, and a bottom surface opposite to the top surface and including the second opposing surface, The recess of the top plate extends to a region of the bottom surface of the top plate that overlaps with the winding core portion when viewed in a direction perpendicular to the axial direction and perpendicular to the top surface of the top plate.

[0023] According to the embodiment, even if the first flange portion is positioned shifted toward the area overlapping with the winding core portion with respect to the top plate, the distance between the second opposing surface and the first opposing surface can be reduced, thereby improving the coil characteristics.

[0024] Preferably, in one embodiment of the coil component, In the cross section, the radius of curvature of the recess of the top plate is larger than the radius of curvature of the protrusion of the first flange portion.

[0025] According to the above embodiment, the distance between the opposing surface on the top plate side and the opposing surface on the first flange side can be more reliably reduced at the top of the convex portion in a direction perpendicular to the top surface of the top plate, compared to when the radius of curvature of the concave portion of the top plate is smaller than the radius of curvature of the convex portion of the first flange portion.

[0026] Preferably, in one embodiment of the coil component, In the cross section, the center of curvature of the circle of the recess of the top plate is located outside the first flange portion.

[0027] According to the embodiment, the radius of curvature of the recess of the top plate can be made larger than when the center of the circle of curvature of the recess of the top plate is located inside the first flange. This makes it easier to control the depth of the recess when forming the top plate, and reduces the variation in the depth of the recess. As a result, the variation in the coil characteristics can also be reduced.

[0028] Preferably, in one embodiment of the coil component, In the cross section, the center of curvature of the circle of curvature of the convex portion of the first flange portion is located outside the first flange portion.

[0029] According to the embodiment, the radius of curvature of the convex portion of the first flange can be made larger than when the center of the circle of curvature of the convex portion of the first flange is located inside the first flange. This makes it easier to control the height of the convex portion during core molding, and reduces the variation in the height of the convex portion. As a result, the variation in coil characteristics can also be reduced.

[0030] Preferably, in one embodiment of the coil component, Further, an adhesive is provided to bond the core and the top plate, The adhesive contains magnetic powder.

[0031] According to the embodiment, since the adhesive contains magnetic powder, the coil characteristics can be improved compared to a case where the adhesive does not contain magnetic powder.

[0032] Preferably, in one embodiment of the method for manufacturing a coil component, a step of first press-molding a core material to form a core molded body, and firing the core molded body to form a core having a protrusion on a first flange portion; A step of forming a top plate having a recess by subjecting the top plate material to a second press molding to form a top plate molded body and firing the top plate molded body; winding a coil around a core portion of the core; and combining the core around which the coil is wound with the top plate.

[0033] According to the embodiment, a coil component capable of improving coil characteristics can be manufactured.

[0034] Preferably, in one embodiment of the method for manufacturing a coil component, In the first press molding, the core compact is compressed by one upper punch and one lower punch.

[0035] According to the embodiment, the convex portion can be easily formed on the first flange portion of the core.

[0036] Preferably, in one embodiment of the method for manufacturing a coil component, In the second press molding, the top plate compact is compressed by one upper punch and one lower punch.

[0037] According to the embodiment, the top plate molded body can be easily manufactured.

[0038] A coil component according to one aspect of the present disclosure includes: A core having a winding core portion extending in an axial direction and a first flange portion and a second flange portion provided at both ends of the winding core portion in the axial direction; A coil wound around the winding core; A top plate provided so as to straddle the first flange portion and the second flange portion, The first flange portion has a first opposing surface that faces the top plate, the top plate has a second opposing surface opposing the first flange portion, In a cross section perpendicular to the axial direction and intersecting the first flange portion, The second opposing surface is provided with a convex portion having a convex shape that is convex toward the first flange portion when viewed from the axial direction, The first opposing surface is provided with a recess having a concave shape corresponding to the convex shape of the convex portion of the top plate.

[0039] According to the above aspect, since the convex shape of the convex portion on the top plate corresponds to the concave shape of the concave portion on the first flange, the distance between the opposing surface on the top plate side and the opposing surface on the first flange side can be made smaller than when a core having a convex portion on the top surface of the first flange is combined with a top plate having a flat bottom surface. As a result, the magnetic resistance caused by the space between the opposing surface on the top plate side and the opposing surface on the first flange side can be reduced, improving the coil characteristics. Effect of the Invention

[0040] According to the coil component according to one aspect of the present disclosure, it is possible to improve the coil characteristics. [Brief description of the drawings]

[0041] [Figure 1] 1 is a perspective view showing a first embodiment of a coil component as viewed from below. FIG. [Diagram 2] FIG. 13 is a view of the coil component as seen from the L direction. [Diagram 3] This is a view of the top plate from the bottom side. [Figure 4] 1 is a view of the core as viewed from above the first and second flanges. FIG. [Diagram 5] FIG. 2 is a cross-sectional view of FIG. 1 . [Figure 6] 13 is a cross-sectional view for explaining the circle of curvature of the recess of the top plate and the circle of curvature of the protrusion of the first flange. FIG. [Figure 7A] 4A to 4C are diagrams for explaining a method of forming a core molded body. [Figure 7B] 4A to 4C are diagrams for explaining a method of forming a core molded body. [Figure 7C] 4A to 4C are diagrams for explaining a method of forming a core molded body. [Figure 7D] 4A to 4C are diagrams for explaining a method of forming a core molded body. [Figure 7E] 4A to 4C are diagrams for explaining a method of forming a core molded body. [Figure 7F] 4A to 4C are diagrams for explaining a method of forming a core molded body. [Figure 8A]11A to 11C are diagrams for explaining a method of forming a top plate molding. [Figure 8B] 11A to 11C are diagrams for explaining a method of forming a top plate molding. [Figure 8C] 11A to 11C are diagrams for explaining a method of forming a top plate molding. [Figure 9] FIG. 4 is a cross-sectional view showing a second embodiment of the coil component. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] Hereinafter, a coil component and a method for manufacturing a coil component according to one aspect of the present disclosure will be described in detail with reference to the illustrated embodiments. Note that the drawings include some schematic views and may not reflect actual dimensions or ratios.

[0043] [First embodiment] (Overall composition) Fig. 1 is a perspective view seen from below showing a first embodiment of a coil component. As shown in Fig. 1, the coil component 1 includes a core 10, a first wire 21 and a second wire 22 wound around the core 10, a first terminal electrode 31, a second terminal electrode 32, a third terminal electrode 33, and a fourth terminal electrode 34 provided on the core 10 and electrically connected to the first wire 21 and the second wire 22, and a top plate 15 attached to the core 10. The first wire 21 and the second wire 22 correspond to a "coil" in the claims.

[0044] The core 10 has a winding core portion 13 extending in the axial direction AX, and a first flange portion 11 and a second flange portion 12 provided on both ends in the axial direction of the winding core portion 13. Specifically, the core 10 has the winding core portion 13 having a shape extending in the axial direction AX and around which a first wire 21 and a second wire 22 are wound, the first flange portion 11 provided at a first end in the axial direction of the winding core portion 13 and protruding in a direction perpendicular to the axial direction AX, and the second flange portion 12 provided at a second end in the axial direction of the winding core portion 13 and protruding in a direction perpendicular to the axial direction AX.

[0045] The shape of the winding core 13 is not particularly limited, but in this embodiment, the cross section of the winding core 13 perpendicular to the axis AX is rectangular. The cross section may be another polygonal shape such as a hexagon, a circle, an ellipse, or an appropriate combination of these. The material of the core 10 is preferably a magnetic material such as a sintered ferrite or a molded body of a resin containing magnetic powder, or may be a non-magnetic material such as alumina or resin.

[0046] In the following description, the bottom surface of the core 10 is the surface to be mounted on the mounting board, and the surface opposite to the bottom surface of the core 10 is the top surface of the core 10. The axis AX direction of the winding core part 13 is the L direction, the direction perpendicular to the L direction on the bottom surface of the core 10 is the W direction, and the opposing direction of the bottom surface and the top surface of the core 10 is the T direction. The T direction is perpendicular to the L direction and the W direction. The positive direction of the T direction is the upward direction, and the negative direction of the T direction is the downward direction. In other words, the bottom surface of the core 10 corresponds to the downward vertical direction, and the top surface of the core 10 corresponds to the upward vertical direction. The L direction is also referred to as the length direction of the core 10, the W direction is the width direction of the core 10, and the T direction is the height direction of the core 10. The W direction corresponds to the "direction perpendicular to the axial direction and parallel to the top surface of the top plate" described in the claims. The T direction corresponds to the "direction perpendicular to the top surface of the top plate" described in the claims.

[0047] The first flange portion 11 has an inner end surface 111 facing toward the winding core portion 13, an outer end surface 112 facing the opposite side to the inner end surface 111, a bottom surface 113 connecting the inner end surface 111 and the outer end surface 112 and facing the mounting board side during mounting, an upper surface 114 facing the opposite side to the lower surface 113, and two side surfaces 115 connecting the inner end surface 111 and the outer end surface 112 and connecting the lower surface 113 and the upper surface 114.

[0048] The second flange portion 12 has an inner end surface 121 facing toward the winding core portion 13, an outer end surface 122 facing the opposite side to the inner end surface 121, a bottom surface 123 connecting the inner end surface 121 and the outer end surface 122 and facing the mounting board side during mounting, an upper surface 124 facing the opposite side to the lower surface 123, and two side surfaces 125 connecting the inner end surface 121 and the outer end surface 122 and connecting the lower surface 123 and the upper surface 124.

[0049] The top plate 15 is fixed so as to straddle the pair of the first flange portion 11 and the second flange portion 12. The top plate 15 has a bottom surface 151 facing the core 10 side and a top surface 152 facing the opposite side of the bottom surface 151. The top plate 15 is arranged so that the top surface 152 is parallel to the WL plane. The shape of the top plate 15 when viewed from the T direction is not particularly limited, but in this embodiment, it is rectangular having a long side parallel to the L direction and a short side parallel to the W direction. The top surface 152 corresponds to the "top surface opposite to the second opposing surface" described in the claims. The bottom surface 151 corresponds to the "bottom surface opposite to the top surface and including the second opposing surface" described in the claims.

[0050] The top plate 15 is attached to the upper surface 114 of the first flange portion 11 and the upper surface 124 of the second flange portion 12 by the adhesive 51. The adhesive 51 is preferably a thermosetting epoxy resin. The adhesive 51 is preferably added with an inorganic filler such as a silica filler in order to improve thermal shock resistance. Examples of the method of applying the adhesive 51 include the following methods. When the adhesive 51 is applied only to the core 10, a method of dipping the upper surface 114 of the first flange portion 11 and the upper surface 124 of the second flange portion 12 in the adhesive 51 can be used. When the adhesive 51 is applied only to the top plate 15, a method of applying the adhesive 51 to the top plate 15 using a dispenser, or a method of printing the adhesive 51 on the top plate 15 using a printer can be used. The adhesive 51 preferably contains magnetic powder. This can improve the coil characteristics more than when the adhesive 51 does not contain magnetic powder.

[0051] The material of the top plate 15 is, for example, the same as that of the core 10. Since the core 10 and the top plate 15 are both magnetic bodies, they form a closed magnetic circuit, improving the efficiency of obtaining the inductance value. Therefore, the magnetic efficiency is increased, and the desired inductance value can be obtained with a smaller number of wires.

[0052] The bottom surface 151 of the top plate 15 preferably has a notch (resin reservoir) 15n at least at one of both ends in the W direction. This allows the adhesive 51 to be guided and stored in the notch 15n when the core 10 and the top plate 15 are bonded together using the adhesive 51. Therefore, even if the amount of adhesive 51 becomes excessive, the adhesive 51 can be prevented from overflowing outside the coil component 1. In this embodiment, the notch 15n is provided over the entire circumference of the bottom surface 151 of the top plate 15. In other words, the notch 15n is provided over the entire ridge between the bottom surface 151 and the side surface of the top plate 15. The notch 15n may be provided in a part of the outer circumference of the bottom surface 151 of the top plate 15, or may not be provided on the top plate 15.

[0053] The shape of the first flange 11 is not particularly limited except for the shape of the upper surface 114. In this embodiment, the first flange 11 has two legs on the lower surface 113 side, one of which is provided with the first terminal electrode 31, and the other is provided with the second terminal electrode 32. Similarly, the shape of the second flange 12 is not particularly limited except for the shape of the upper surface 124. In this embodiment, the second flange 12 has two legs on the lower surface 123 side, one of which is provided with the first terminal electrode 31, and the third terminal electrode 33 is provided on the one of which is provided with the first terminal electrode 31, and the fourth terminal electrode 34 is provided on the other of which is provided with the second terminal electrode 32. As shown in FIG. 1, the lower surface 113 and the lower surface 123 each refer to a portion extending from the bottom surface of the foot through a side surface of the crotch between the foot portions and including the bottom surface of the crotch.

[0054] The conductive material of the first to fourth terminal electrodes 31 to 34 is not particularly limited, but preferably contains a metal with good conductivity such as Ag or Cu. The first to fourth terminal electrodes 31 to 34 are formed, for example, by applying Ag paste containing Ag, Si, and resin to the lower surface 113 of the first flange portion 11 and the lower surface 123 of the second flange portion 12 by a dipping method, and then baking the paste to form a base electrode. Then, the electrodes are formed by plating a thin film of Cu / Ni / Sn, etc. The first to fourth terminal electrodes 31 to 34 may be formed by attaching a metal plate to the lower surface 113 and outer end surface 112 of the first flange portion 11, and the lower surface 123 and outer end surface 122 of the second flange portion 12, using an adhesive.

[0055] The first wire 21 and the second wire 22 are preferably insulating coated conductors in which a conductor made of a conductive metal such as copper, silver, or gold is covered with a coating made of a resin such as polyurethane or polyamideimide. The wire diameter of each of the first wire 21 and the second wire 22 is preferably 20 μm or more and 50 μm or less. One end of the first wire 21 is electrically connected to the first terminal electrode 31, and the other end is electrically connected to the third terminal electrode 33. One end of the second wire 22 is electrically connected to the second terminal electrode 32, and the other end is electrically connected to the fourth terminal electrode 34. The first wire 21 and the second wire 22 are connected to the first to fourth terminal electrodes 31 to 34 by, for example, thermocompression bonding, brazing, welding, or the like.

[0056] The first wire 21 and the second wire 22 are wound in the same direction around the winding core 13. As a result, in the coil component 1, when a signal of opposite phase, such as a differential signal, is input to the first wire 21 and the second wire 22, the magnetic fluxes generated by the first wire 21 and the second wire 22 cancel each other out, weakening the inductor function and allowing the signal to pass. On the other hand, when a signal of the same phase, such as an external noise, is input to the first wire 21 and the second wire 22, the magnetic fluxes generated by the first wire 21 and the second wire 22 reinforce each other, strengthening the inductor function and blocking the passage of the noise. Therefore, the coil component 1 functions as a common mode choke coil that reduces the passage loss of a differential mode signal, such as a differential signal, while attenuating a common mode signal, such as an external noise.

[0057] When the coil component 1 is mounted on a mounting board, the lower surface 113 of the first flange portion 11 and the lower surface 123 of the second flange portion 12 face the mounting board. At this time, the axis AX direction of the winding core portion 13 and the main surface of the mounting board are parallel to each other. In other words, the coil component 1 is a horizontally wound type in which the winding axes of the first wire 21 and the second wire 22 are parallel to the mounting board.

[0058] (Details of the bottom surface of the tabletop and the top surfaces of the first and second flanges) Next, the detailed configuration of the bottom surface 151 of the top plate 15 and the top surfaces 114, 124 of the first and second flange portions 11, 12 will be described. Fig. 2 is a view of the coil device 1 seen from the L direction. Fig. 3 is a view of the top plate 15 seen from the bottom surface 151 side. Fig. 4 is a view of the core 10 seen from the top surfaces 114, 124 sides of the first flange portion 11 and the second flange portion 12.

[0059] 2, 3, and 4, the first flange 11 and the top plate 15 each have opposing surfaces that face each other. Specifically, the top surface 114 of the first flange 11 has a first opposing surface 11f that faces the top plate 15. The first opposing surface 11f is a portion of the top surface 114 of the first flange 11 that overlaps with the top plate 15 when viewed from the T direction. In this embodiment, the first opposing surface 11f is the entire surface of the top surface 114 of the first flange 11.

[0060] The bottom surface 151 of the top plate 15 has a second opposing surface 15f1 facing the first flange portion 11. The second opposing surface 15f1 is a portion of the bottom surface 151 of the top plate 15 that overlaps with the first flange portion 11 when viewed from the T direction. In this embodiment, the second opposing surface 15f1 is an end portion of the bottom surface 151 of the top plate 15 on the first flange portion 11 side.

[0061] The first opposing surface 11f on the first flange 11 side is provided with a convex portion P having a convex shape that is convex toward the top plate 15 side in a cross section perpendicular to the axis AX direction and intersecting with the first flange 11. The convex shape of the convex portion P is a convex curved surface that is convex toward the top plate 15 side when viewed from the axis AX direction. In this embodiment, the convex portion P is provided on the entire upper surface 114 of the first flange 11. That is, the entire upper surface 114 of the first flange 11 is a convex curved surface that is convex toward the top plate 15 side when viewed from the axis AX direction. However, this is not limited to this, and the convex portion P may be provided on a part of the upper surface 114 of the first flange 11. For example, both ends of the upper surface 114 of the first flange 11 in the W direction may be flat surfaces, and the portions other than both ends may be convex curved surfaces.

[0062] The protrusion P has a top portion P1 as viewed from the axis AX direction. The top portion P1 is the uppermost portion of the protrusion P. In this embodiment, the top portion P1 extends in the L direction as viewed from the T direction. That is, the protrusion P has the same shape in any cross section perpendicular to the axis AX direction. However, this is not limited thereto, and the protrusion P may have different shapes depending on the cross section perpendicular to the axis AX direction. Note that in FIG. 4, for convenience, the position where the protrusion P exists is shaded.

[0063] The second opposing surface 15f1 on the top plate 15 side is provided with a concave portion C having a concave shape corresponding to the convex shape of the convex portion P of the first flange portion 11. The concave shape corresponding to the convex shape of the convex portion P refers to a concave shape in which the entire inner surface of the concave portion C contacts the surface of the convex portion P when the concave portion C and the convex portion P are brought closer to each other in the T direction, or a concave shape in which the inner surface shape of the concave portion C is a shape that follows the surface shape of the convex portion P, and when the concave portion C and the convex portion P are brought closer to each other in the T direction, a part of the inner surface of the concave portion C contacts a part of the surface of the convex portion P and another part of the inner surface of the concave portion C is separated from the surface of the convex portion P by a small distance. The small distance is, for example, more than 0 μm and not more than 10 μm, and more specifically, is 1 μm or more and not more than 5 μm.

[0064] In this embodiment, the concave shape of the recess C is a concave curved surface recessed inwardly of the top plate 15 as viewed from the axis AX direction. The second opposing surface 15f1 is provided with notches 15n at both ends in the W direction and at the end on the first flange portion 11 side in the L direction, and the recess C is provided in the entire portion other than the notches 15n. That is, the entire portion of the second opposing surface 15f1 other than the notches 15n is a concave curved surface recessed inwardly of the top plate 15 as viewed from the axis AX direction. However, this is not limited thereto, and the recess C may be provided in a part of the second opposing surface 15f1 other than the notches 15n. In addition, when the notches 15n are not provided in the top plate 15, the recess C may be provided in the entire second opposing surface 15f1.

[0065] The inner surface of the recess C has a top portion C1 when viewed from the axis AX direction. The top portion C1 is the uppermost portion of the inner surface of the recess C. In this embodiment, the top portion C1 extends in the L direction when viewed from the T direction. That is, the recess C has the same shape in any cross section perpendicular to the axis AX direction. However, this is not limited thereto, and the recess C may have a different shape depending on the cross section perpendicular to the axis AX direction. Note that in FIG. 3, for convenience, the position where the recess C exists is shaded.

[0066] The convex shape of the convex portion P and the concave shape of the concave portion C can be confirmed by non-contact optical measurement using, for example, a hybrid laser microscope (OPTELICS HYBRID+) manufactured by Lasertec Corp. In the optical measurement, for example, phase shift interference measurement may be performed.

[0067] In this embodiment, the top surface 152 of the top plate 15 is a flat surface, but it does not have to be a flat surface. For example, the top surface 152 may be a concave curved surface recessed inward of the top plate 15. In this case, the "top surface" in the "direction parallel to the top surface of the top plate" and the "direction perpendicular to the top surface of the top plate" described in the claims may be a virtual plane connecting the periphery of the top surface 152 of the top plate 15. Also, for example, if the periphery of the top surface 152 of the top plate 15 is provided with a notch or is rounded, the "top surface" in the "direction parallel to the top surface of the top plate" and the "direction perpendicular to the top surface of the top plate" described in the claims may be a portion of the top surface 152 excluding the portion provided with the notch or the portion rounded.

[0068] The second flange 12 has the same configuration as described above. That is, the second flange 12 and the top plate 15 each have opposing surfaces that face each other. The first opposing surface 12f on the second flange 12 side is provided with a convex protrusion P that is convex toward the top plate 15 side when viewed from the axis AX direction. The second opposing surface 15f2 on the top plate 15 side is provided with a concave recess C that is concave in shape corresponding to the convex shape of the protrusion P of the second flange 12.

[0069] According to the coil component 1, the convex shape of the convex portion P provided on the first flange portion 11 and the second flange portion 12 corresponds to the concave shape of the concave portion C provided on the top plate 15, so that the distance between the second opposing surfaces 15f1, 15f2 on the top plate 15 side and the first opposing surfaces 11f, 12f on the first flange portion 11 side and the second flange portion 12 side can be made smaller than when a core having convex portions on the upper surface of the first flange portion 11 and the upper surface of the second flange portion is combined with a top plate having a flat bottom surface. As a result, the magnetic resistance generated by the space between the second opposing surfaces 15f1, 15f2 on the top plate 15 side and the first opposing surfaces 11f, 12f on the first flange portion 11 side and the second flange portion 12 side is reduced, and the effective permeability is increased, thereby improving the coil characteristics. The coil characteristics are, for example, inductance and common mode noise attenuation characteristic Scc21.

[0070] (Other preferred configurations) Fig. 5 is a VV cross-sectional view of Fig. 1. Fig. 5 is a cross-sectional view of the coil device 1 cut on the WT plane. The cross section of Fig. 5 corresponds to the "cross section perpendicular to the axial direction and intersecting with the first flange" described in the claims. For convenience, the adhesive 51 is omitted from Fig. 5.

[0071] 5, preferably, the uppermost portion P1 of the protrusion P of the first flange 11 is disposed at the center of the first flange 11 in the W direction. With this configuration, even if the first flange 11 is disposed offset in the W direction with respect to the top plate 15, the distance between the second opposing surface 15f1 on the top plate 15 side and the first opposing surface 11f on the first flange 11 side can be more reliably reduced at the uppermost portion P1 of the protrusion P. Similarly, the uppermost portion P1 of the protrusion P of the second flange 12 may be disposed at the center of the second flange 12 in the W direction as viewed from the axis AX direction.

[0072] Preferably, (i) the top C1 of the inner surface of the recess C, (ii) the top P1 of the protrusion P, and (iii) at least one of both ends of the recess C in the W direction are arranged in this order from the top plate 15 side. Specifically, in the T direction, the top C1 of the inner surface of the recess C, the top P1 of the protrusion P, and the first end CE1 of the recess C in the W direction are arranged in this order from the top plate 15 side. Also, in the T direction, the top C1 of the inner surface of the recess C, the top P1 of the protrusion P, and the second end CE2 of the recess C in the W direction are arranged in this order from the top plate 15 side. With this configuration, the distance between the second opposing surface 15f1 on the top plate 15 side and the first opposing surface 11f on the first flange 11 side can be more reliably reduced across the W direction.

[0073] Preferably, when viewed from the T direction, each of the convex portion P and the concave portion C has an overlapping area, and the distance between the convex portion P and the concave portion C at both ends in the W direction of the overlapping area is greater than the distance between the convex portion P and the concave portion C at the center of the overlapping area in the W direction.

[0074] Specifically, the recess C has an area R1 that overlaps with the protrusion P when viewed from the T direction. The protrusion P has an area R2 that overlaps with the recess C when viewed from the T direction. The distance D2 between the protrusion P and the recess C at the end of one side of the areas R1 and R2 in the W direction is greater than the distance D1 between the protrusion P and the recess C at the center of the areas R1 and R2 in the W direction. The distance D3 between the protrusion P and the recess C at the end of the other side of the areas R1 and R2 in the W direction is greater than the distance D1 between the protrusion P and the recess C at the center of the areas R1 and R2 in the W direction. The distance D1 is, for example, 0 μm or more and 2 μm or less. The distance D1 being 0 μm means that the top plate 15 and the first flange portion 11 are in contact with each other at the center of the areas R1 and R2 in the W direction. The distance D2 and the distance D3 are, for example, more than 0 μm and not more than 10 μm, more specifically, not less than 1 μm and not more than 5 μm. With this configuration, the distance between the second opposing surface 15f1 on the top plate 15 side and the first opposing surface 11f on the first flange portion 11 side can be more reliably reduced in the center of the regions R1 and R2 in the W direction. In particular, when the distance D2 and the distance D3 are set to 10 μm or less, the coil characteristics of the coil component 1 can be further improved.

[0075] Preferably, the top of the inner surface of cutout 15n, the top C1 of the inner surface of recess C, the top P1 of protrusion P, and of both ends of recess C in the W direction, ends CE1, CE2 on the side where cutout 15n is provided are arranged in this order from the top plate 15 side. The top of the inner surface of cutout 15n is the part located at the uppermost position on the inner surface of cutout 15n.

[0076] Specifically, the inner surface of the notch 15n has an inner top surface 15n1 extending along the WL plane and an inner side surface 15n2 extending along the LT plane. In this embodiment, the inner top surface 15n1 is the uppermost part of the inner surface of the notch 15n. In the T direction, the inner top surface 15n1, the uppermost part C1 of the inner surface of the recess C, the uppermost part P1 of the protrusion P, and the ends CE1 and CE2 on the side where the notch 15n is provided among both ends of the recess C in the W direction are arranged in this order from the top plate 15 side. The shape of the inner surface of the notch 15n is not particularly limited. According to this configuration, the size of the notch 15n can be increased, so that more adhesive can be guided and stored in the notch 15n, and therefore the adhesive can be more reliably prevented from spilling out of the coil component 1.

[0077] Preferably, when viewed from the T direction, the notch 15n overlaps with the protrusion P of the first flange 11. With this configuration, compared to a case in which the notch 15n does not overlap with the protrusion P of the first flange 11, it is possible to suppress leakage of the adhesive 51 from the ends CE1, CE2 of the recess C in the W direction to the outside of the coil component 1, and it is possible to more reliably guide the adhesive 51 to the notch 15n.

[0078] 3, the recess C of the top plate 15 preferably extends to a region R3 of the bottom surface 151 of the top plate 15 that overlaps with the winding core portion 13 when viewed from the T direction. Specifically, the recess C of the top plate 15 extends in the L direction from a portion of the recess C provided in the second opposing surface 15f1 when viewed from the T direction, and is connected to a portion of the recess C provided in the second opposing surface 15f2.

[0079] According to the above configuration, even if the first flange 11 is arranged shifted toward the region R3 side overlapping with the winding core 13 with respect to the top plate 15, the distance between the second opposing surface 15f1 on the top plate 15 side and the first opposing surface 11f on the first flange 11 side can be reduced, improving the coil characteristics. Similarly, even if the second flange 12 is arranged shifted toward the region R3 side overlapping with the winding core 13 with respect to the top plate 15, the distance between the second opposing surface 15f2 on the top plate 15 side and the first opposing surface 12f on the second flange 12 side can be reduced, improving the coil characteristics.

[0080] FIG. 6 is a cross-sectional view for explaining the circle of curvature of the recess C of the top plate 15 and the circle of curvature of the protrusion P of the first flange portion 11. FIG. 6 is the same cross section as FIG. 5. For convenience, the adhesive 51 and the terminal electrodes 31, 32 are omitted from FIG. 6. As shown in FIG. 6, the radius of curvature r1 of the recess C of the top plate 15 is preferably larger than the radius of curvature r2 of the protrusion P of the first flange portion 11. The radius of curvature r1 is, for example, 70 mm. The radius of curvature r2 is, for example, 60 mm.

[0081] According to the above configuration, the distance between the second opposing surface 15f1 on the top plate 15 side and the first opposing surface 11f on the first flange 11 side can be more reliably reduced at the uppermost part P1 of the protrusion P in the T direction compared to the case where the radius of curvature r1 of the recess C of the top plate 15 is smaller than the radius of curvature r2 of the protrusion P of the first flange 11. Similarly, on the second flange 12 side, the radius of curvature of the recess C of the top plate 15 may be larger than the radius of curvature of the protrusion P of the second flange 12 when viewed from the axis AX direction.

[0082] Preferably, the center CC1 of the curvature circle CC of the recess C of the top plate 15 is located outside the first flange portion 11. With this configuration, the radius of curvature r1 of the recess C of the top plate 15 can be made larger than when the center CC1 of the curvature circle CC of the recess C of the top plate 15 is located inside the first flange portion 11. This makes it easier to control the depth of the recess C when forming the top plate 15, and can reduce the variation in the depth of the recess C. As a result, the variation in the coil characteristics can also be reduced. Similarly, on the second flange portion 12 side, the center of the curvature circle of the recess C of the top plate 15 may be located outside the second flange portion 12 when viewed from the axis AX direction.

[0083] Preferably, the center PC1 of the curvature circle PC of the convex portion P of the first flange portion 11 is located outside the first flange portion 11. According to this configuration, the radius of curvature r2 of the convex portion P of the first flange portion 11 can be made larger than when the center PC1 of the curvature circle PC of the convex portion P of the first flange portion 11 is located inside the first flange portion 11. This makes it easier to control the height of the convex portion P when forming the core 10, and the variation in the height of the convex portion P can be reduced. As a result, the variation in the coil characteristics can also be reduced. Similarly, on the second flange portion 12 side, the center of the curvature circle of the convex portion P of the second flange portion 12 may be located outside the second flange portion 12 when viewed from the axis AX direction.

[0084] (Manufacturing method) Next, a method for manufacturing the coil component 1 will be described. The method for manufacturing the coil component 1 is as follows: a step of first press-molding a core material to form a core molded body, and firing the core molded body to form a core 10 having a protrusion P on a first flange portion 11; A step of forming a top plate 15 having a recess C by performing a second press molding on the top plate material to form a top plate molded body and firing the top plate molded body; a step of winding a first wire 21 and a second wire 22 around a winding core portion 13 of a core 10; and combining the core 10 around which the first wire 21 and the second wire 22 are wound with the top plate 15.

[0085] Preferably, the first press molding compresses the core body with one upper punch and one lower punch. This configuration makes it possible to easily form a convex portion on the first flange portion 11 of the core 10. Also, the manufacturing cost can be reduced compared to the case where the core body is compressed with multiple upper punches and multiple lower punches.

[0086] Preferably, the second press molding compresses the top plate molding body with one upper punch and one lower punch. With this configuration, the top plate molding body can be easily manufactured. Also, the manufacturing cost can be reduced compared to the case where the top plate molding body is compressed with multiple upper punches and multiple lower punches.

[0087] An example of a method for manufacturing the coil component 1 will be specifically described with reference to Figs. 7A to 7F and Figs. 8A to 8C. Figs. 7A to 7F are diagrams for explaining a method for forming a core molded body. Figs. 8A to 8C are diagrams for explaining a method for forming a top plate molded body. Figs. 7A to 7F correspond to the "first press molding" described in the claims. Figs. 8A to 8C correspond to the "second press molding" described in the claims. Note that the method described below is an example, and the method for manufacturing the coil component 1 is not limited to the method described below.

[0088] <Core formation> As shown in Fig. 7A, a feeder (raw material supplying section) 61 filled with a core material 1010 is moved above a die 62. A lower punch 71l is disposed at the lower opening of the die 62. The upper surface of the lower punch 71l is shaped to correspond to the shape of the core 10 to be formed. The core material 1010 is, for example, ferrite powder.

[0089] As shown in Fig. 7B, the core material 1010 is filled into the die 62. As shown in Fig. 7C, after the feeder 61 in which the core material 1010 has been filled is removed, the upper punch 71u is placed on the die 62. The lower surface of the upper punch 71u has a shape corresponding to the shape of the core 10 to be formed. In addition, the lower surface of the upper punch 71u has a concave shape for forming the convex shape of the convex portion P of the first flange portion 11 and the second flange portion 12.

[0090] As shown in FIG. 7D, the upper punch 71u is inserted into the die 62, and the core material 1010 is compressed. This forms a core molded body 10m that will become the core 10. In this manner, the core molded body 10m is compressed by one upper punch 71u and one lower punch 71l. That is, the portion that will become the winding core 13, the portion that will become the first flange 11, and the portion that will become the second flange 12 are simultaneously formed by one upper punch 71u and one lower punch 71l. However, this is not limited to this, and the core molded body 10m may be compressed by multiple upper punches. Specifically, the portion that will become the winding core 13 may be formed by a first upper punch, and the portion that will become the first flange 11 and the portion that will become the second flange 12 may be formed by a second upper punch different from the first upper punch.

[0091] As shown in FIG. 7E, the upper punch 71u is moved upward. As shown in FIG. 7F, after removing the upper punch 71u, the lower punch 71l is moved upward to take out the core molded body 10m. The core molded body 10m has a first portion 11a that will become the first flange portion 11, a second portion 12a that will become the second flange portion 12, and a third portion 13a that will become the winding core portion 13. A convex portion P0 that will become the convex portion P is formed on the upper surface of the first portion 11a and the upper surface of the second portion 12a. The core molded body 10m is then fired to form the core 10 having the convex portion P on the first flange portion 11 and the second flange portion 12. Then, barrel polishing is performed to remove burrs. Then, the bottom side of the core 10 is dipped in Ag paste and fired, and then a thin film of Cu / Ni / Sn is plated to form the first to fourth terminal electrodes 31 to 34.

[0092] The method of forming the protrusions P is not limited to the above. For example, the density of the powder in the core molded body 10m may be made non-uniform, and the protrusions P may be formed after firing. Specifically, for example, in the core molded body 10m, the powder density of the first portion 11a that becomes the first flange portion 11 and the powder density of the second portion 12a that becomes the second flange portion 12 are made smaller than the powder density of the third portion 13a that becomes the winding core portion 13. The portion with the lower powder density has a higher shrinkage rate after firing than the portion with the higher powder density. Therefore, the shrinkage rate after firing is larger in the first portion 11a and the second portion 12a, and the protrusions P are formed in the first flange portion 11 and the second flange portion 12.

[0093] <Forming the top plate> As shown in Fig. 8A, the die 63 is filled with a top plate material 1015. A lower punch 72l is disposed in the lower opening of the die 63. The upper surface of the lower punch 72l is shaped to correspond to the shape of the top plate 15 to be formed. The top plate material 1015 is, for example, ferrite powder.

[0094] As shown in FIG. 8B, the upper punch 72u is inserted into the die 63, and the top plate material 1015 is compressed. This forms a top plate forming body 15m that will become the top plate 15. In this manner, the top plate forming body 15m is compressed by one upper punch 72u and one lower punch 72l. The lower surface of the upper punch 72u is shaped to correspond to the shape of the top plate 15 to be formed. In addition, the lower surface of the upper punch 72u has a convex shape for forming the concave shape of the recess C of the top plate 15.

[0095] As shown in Fig. 8C, after removing the upper punch 72u, the lower punch 72l is moved upward to remove the top plate molding 15m. A recess C0 that will become the recess C of the top plate 15 is formed on the top surface of the top plate molding 15m. The top plate molding 15m is then fired to form the top plate 15 having the recess C.

[0096] <Coil winding and coil component assembly> Thereafter, the first wire 21 and the second wire 22 are wound around the winding core portion 13 of the core 10 by a nozzle. Then, the first wire 21 and the second wire 22 are crimped to the first to fourth terminal electrodes 31 to 34 by a heater tip. Thereafter, the top plate 15 is attached to the core 10 by an adhesive 51, and the coil component 1 is manufactured.

[0097] [Second embodiment] Fig. 9 is a cross-sectional view showing a coil component according to a second embodiment. Fig. 9 corresponds to Fig. 5 of the first embodiment. The second embodiment differs from the first embodiment in that a convex portion is provided on the top plate side, and concave portions are provided on the first flange side and the second flange side. The other configurations are the same as those of the first embodiment, and the same reference numerals as those of the first embodiment are used, and the description thereof will be omitted.

[0098] 9, the second opposing surface 15f1 on the top plate 15A side is provided with a convex protrusion P that is convex toward the first flange 11A side when viewed from the axis AX direction. The first opposing surface 11f on the first flange 11A side is provided with a concave recess C that is concave corresponding to the convex shape of the protrusion P of the top plate 15A. Similarly, on the second flange side, the second opposing surface on the top plate 15A side is provided with a convex protrusion P that is convex toward the second flange side when viewed from the axis AX direction, and the first opposing surface on the second flange side is provided with a concave recess C that is concave corresponding to the convex shape of the protrusion P of the top plate 15A.

[0099] According to the above configuration, the convex shape of the convex portion P on the top plate 15A corresponds to the concave shape of the concave portion C on the first flange portion 11A and the second flange portion, so the distance between the second opposing surface on the top plate 15A side and the first opposing surface on the first flange portion 11A side and the second flange portion side can be made smaller than when a core having convex portions on the upper surface of the first flange portion 11A and the upper surface of the second flange portion is combined with a top plate having a flat bottom surface. As a result, the magnetic resistance caused by the space between the second opposing surface on the top plate 15A side and the first opposing surface on the first flange portion 11A side and the second flange portion side can be reduced, thereby improving the coil characteristics.

[0100] The present disclosure is not limited to the above-described embodiments, and design modifications are possible without departing from the gist of the present disclosure.

[0101] In the above embodiment, the coil component has two wires, but may have one wire or three or more wires. Also, in the above embodiment, the coil component is used as a common mode choke coil, but may be used as a wound coil in which the wire of a transformer, a coupled inductor, or the like is wound around a winding core.

[0102] In the first embodiment, the first flange and the second flange each have a protrusion, but the protrusion may be provided on only one of the first flange and the second flange. In this case, the recess may be provided at least on the opposing surface of the bottom surface of the top plate that faces the upper surface of the flange on the side where the protrusion is provided. Similarly, in the second embodiment, the first flange and the second flange each have a protrusion, but the recess may be provided on only one of the first flange and the second flange. In this case, the protrusion may be provided at least on the opposing surface of the bottom surface of the top plate that faces the upper surface of the flange on the side where the recess is provided.

[0103] In the first embodiment, in a cross section perpendicular to the axial direction and intersecting the first flange portion, the top of the inner surface of the recess, the top of the convex portion, and both end portions of the recess in a direction parallel to the top surface of the top plate were arranged in this order from the top plate side; however, (i) the top of the inner surface of the recess, (ii) the top of the convex portion, and (iii) either end of both end portions of the recess in a direction parallel to the top surface of the top plate may be arranged in this order from the top plate side.

[0104] In the first embodiment, the bottom surface of the top plate had notches at both ends in a direction perpendicular to the axial direction and parallel to the top surface of the top plate, but the bottom surface of the top plate may have a notch at only one of both ends in a direction perpendicular to the axial direction and parallel to the top surface of the top plate.

[0105] <1> A core having a winding core portion extending in an axial direction and a first flange portion and a second flange portion provided at both ends of the winding core portion in the axial direction; A coil wound around the winding core; A top plate provided so as to straddle the first flange portion and the second flange portion, The first flange portion has a first opposing surface that faces the top plate, the top plate has a second opposing surface opposing the first flange portion, In a cross section perpendicular to the axial direction and intersecting the first flange portion, The first opposing surface is provided with a convex portion having a convex shape that is convex toward the top plate side, The second opposing surface is provided with a recess having a recessed shape corresponding to the convex shape of the convex portion of the first flange portion. <2> The top plate has a top surface opposite to the second opposing surface, In the cross section, the uppermost portion of the protrusion of the first flange portion is disposed at the center of the first flange portion in a direction parallel to the top surface of the top plate. <1> The coil component according to claim 1. <3> The top plate has a top surface opposite to the second opposing surface, In the cross section, when the direction from the core toward the top plate is defined as the upper side, (i) the uppermost part of the inner surface of the recess, (ii) the uppermost part of the protrusion, and (iii) at least one of both ends of the recess in a direction parallel to the top surface of the top plate are arranged in this order from the top plate side. <1> or <2> The coil component according to claim 1. <4> The top plate has a top surface opposite to the second opposing surface, When viewed from a direction perpendicular to the axial direction and perpendicular to the top surface of the top plate, the protrusion and the recess each have an area where they overlap with each other, In the cross section, a distance between the convex portion and the concave portion at both ends of the overlapping region in a direction parallel to the top surface of the tabletop is greater than a distance between the convex portion and the concave portion at a center of the overlapping region in a direction parallel to the top surface of the tabletop. <1> from <3> 13. The coil component according to claim 12, <5> The top plate has a top surface opposite to the second opposing surface, and a bottom surface opposite to the top surface and including the second opposing surface, The bottom surface of the top plate has a notch on at least one of both ends in a direction perpendicular to the axial direction and parallel to the top surface of the top plate. <1> from <4> 13. The coil component according to claim 12, <6> In the cross section, when the direction from the core toward the top plate is defined as the upper side, the top of the inner surface of the notch, the top of the inner surface of the recess, the top of the protrusion, and, of both ends of the recess in a direction parallel to the top surface of the top plate, the end on the side where the notch is provided are arranged in this order from the top plate side. <5> The coil component according to claim 1. <7> When viewed from a direction perpendicular to the top surface of the top plate, the notch overlaps with the protrusion of the first flange portion. <5> or <6> The coil component according to claim 1. <8> The top plate has a top surface opposite to the second opposing surface, and a bottom surface opposite to the top surface and including the second opposing surface, The recess of the top plate extends to a region of the bottom surface of the top plate that overlaps with the winding core portion when viewed in a direction perpendicular to the axial direction and perpendicular to the top surface of the top plate. <1> from <7> 13. The coil component according to claim 12, <9> In the cross section, a radius of curvature of the recess of the top plate is larger than a radius of curvature of the protrusion of the first flange portion. <1> from <8> 13. The coil component according to claim 12, <10> In the cross section, the center of the circle of curvature of the recess of the top plate is located outside the first flange portion. <1> from <9> 13. The coil component according to claim 12, <11> In the cross section, the center of the circle of curvature of the convex portion of the first flange portion is located outside the first flange portion. <1> from <10> 13. The coil component according to claim 12, <12> Further, an adhesive is provided to bond the core and the top plate, The adhesive contains magnetic powder. <1> from <11> 13. The coil component according to claim 12, <13> a step of first press-molding a core material to form a core molded body, and firing the core molded body to form a core having a protrusion on a first flange portion; A step of forming a top plate having a recess by subjecting the top plate material to a second press molding to form a top plate molded body and firing the top plate molded body; winding a coil around a core portion of the core; and combining the core around which the coil is wound with the top plate. <14> The first press molding compresses the core compact with one upper punch and one lower punch. <13> A method for manufacturing the coil component according to claim 1. <15> The second press molding compresses the top plate body using one upper punch and one lower punch. <13> or <14> A method for manufacturing the coil component according to claim 1. <16> A core having a winding core portion extending in an axial direction and a first flange portion and a second flange portion provided at both ends of the winding core portion in the axial direction; A coil wound around the winding core; A top plate provided so as to straddle the first flange portion and the second flange portion, The first flange portion has a first opposing surface that faces the top plate, the top plate has a second opposing surface opposing the first flange portion, In a cross section perpendicular to the axial direction and intersecting the first flange portion, The second opposing surface is provided with a convex portion having a convex shape that is convex toward the first flange portion when viewed from the axial direction, The coil component has a recessed portion on the first opposing surface, the recessed portion having a recessed shape corresponding to the convex shape of the convex portion of the top plate. [Explanation of symbols]

[0106] 1. 1A coil parts 10 cores 10m core molding 11, 11A 1st collar part 11f: First opposing surface on the first flange side 12 Second flange 12f: First opposing surface on the second flange side 13 Winding core 15, 15A Top plate 15m Top plate molding 15f1, 15f2 2nd opposing surface 15n Notch 151 Bottom of the tabletop 152 Top surface of the tabletop 21 First Wire 22 Second Wire 31 1st terminal electrode 32 2nd terminal electrode 33 3rd terminal electrode 34 4th terminal electrode 51 Adhesive 71l, 72l lower punch 71u, 72u upper punch 1010 Core Material 1015 Top plate material r1, r2 radius of curvature C recess C1 Top of the recess CE1, CE2 1st end, 2nd end D1~D3 Distance P convex part P1 Top of the protrusion CC, PC curvature circle CC1, PC1 Center of curvature circle R1 and R2 overlapping area R3 Area overlapping with the core AX Core shaft

Claims

1. A core having a winding core portion extending in an axial direction and a first flange portion and a second flange portion provided at both ends of the winding core portion in the axial direction; A coil wound around the winding core; A top plate provided so as to straddle the first flange portion and the second flange portion, The first flange portion has a first opposing surface that faces the top plate, The top plate has a second opposing surface facing the first flange portion and a top surface opposite to the second opposing surface, In a cross section perpendicular to the axial direction and intersecting the first flange portion, The first opposing surface is provided with a convex portion that is convex toward the top plate, The second opposing surface is provided with a recess having a recess shape corresponding to the convex shape of the convex portion of the first flange portion, The second opposing surface has a notch on at least one of both ends in a direction perpendicular to the axial direction and parallel to the top surface of the top plate, When viewed along the axial direction, the notch has an inner top surface parallel to the top surface and an inner side surface perpendicular to the top surface and extending in a direction from the top plate toward the core, The coil component, wherein the notch overlaps with the protrusion of the first flange portion when viewed from a direction perpendicular to the top surface of the top plate.

2. A coil component as described in Claim 1, wherein, in the cross section, the top of the convex portion of the first flange portion is positioned at the center of the first flange portion in a direction parallel to the top surface of the top plate.

3. A coil component as described in claim 1 or 2, wherein, in the cross section, when the direction from the core toward the top plate is considered the upper side, (i) the top of the inner surface of the recess, (ii) the top of the convex portion, and (iii) at least one of both end portions of the recess in a direction parallel to the top surface of the top plate are arranged in this order from the top plate side.

4. When viewed from a direction perpendicular to the axial direction and perpendicular to the top surface of the top plate, each of the convex portion and the concave portion has an area where they overlap each other, 3. The coil component according to claim 1, wherein in the cross section, a distance between the convex portion and the concave portion at both ends of the overlapping region in a direction parallel to the top surface of the top plate is greater than a distance between the convex portion and the concave portion at a center of the overlapping region in a direction parallel to the top surface of the top plate.

5. 3. The coil component according to claim 1, wherein, in the cross section, when the direction from the core toward the top plate is defined as the upper side, the top of the inner surface of the notch, the top of the inner surface of the recess, the top of the convex portion, and of both ends of the recess in a direction parallel to the top surface of the top plate, the end on the side where the notch is provided are arranged in this order from the top plate side.

6. The top plate has a bottom surface opposite to the top surface and including the second opposing surface, The coil component according to claim 1 , wherein the recess of the top plate extends to a region of the bottom surface of the top plate that overlaps with the winding core portion when viewed in a direction perpendicular to the top surface of the top plate.

7. The coil component according to claim 1 , wherein in the cross section, a radius of curvature of the recess of the top plate is larger than a radius of curvature of the protrusion of the first flange portion.

8. The coil component according to claim 1 , wherein in the cross section, a center of curvature of the circle of the recess of the top plate is positioned outside the first flange portion.

9. The coil component according to claim 1 , wherein in the cross section, a center of curvature of the circle of curvature of the convex portion of the first flange portion is located outside the first flange portion.

10. Further, an adhesive is provided to bond the core and the top plate, The coil component according to claim 1 , wherein the adhesive contains magnetic powder.

11. a step of first press-molding a core material to form a core molded body, and firing the core molded body to form a core having a winding core portion extending in an axial direction, a first flange portion and a second flange portion provided at both ends of the winding core portion in the axial direction, the first flange portion having a protrusion; A step of forming a top plate having a concave recess corresponding to the convex shape of the convex portion and a notch by performing a second press molding of the top plate material and firing the top plate molded body; winding a coil around the winding core portion of the core; a step of combining the core around which the coil is wound and the top plate such that a first opposing surface of the first flange portion on which the protrusion is provided and a second opposing surface of the top plate on which the recess and the notch are provided face each other; The top plate has a top surface opposite to the second opposing surface, The notch is located on at least one of both ends of the second opposing surface in a direction perpendicular to the axial direction and parallel to the top surface of the top plate, When viewed along the axial direction, the notch has an inner top surface parallel to the top surface and an inner side surface perpendicular to the top surface and extending in a direction from the top plate toward the core, A method for manufacturing a coil component, wherein in the assembling process, the core and the top plate are assembled so that the notch overlaps the convex portion of the first flange portion when viewed from a direction perpendicular to the top surface of the top plate.

12. The method for manufacturing a coil component according to claim 11 , wherein the first press molding compresses the core body with one upper punch and one lower punch.

13. The method for manufacturing a coil component according to claim 11 or 12, wherein the second press molding compresses the top plate body with one upper punch and one lower punch.

14. A core having a winding core portion extending in an axial direction and a first flange portion and a second flange portion provided at both ends of the winding core portion in the axial direction; A coil wound around the winding core; A top plate provided so as to straddle the first flange portion and the second flange portion, The first flange portion has a first opposing surface that faces the top plate, The top plate has a second opposing surface facing the first flange portion and a top surface opposite to the second opposing surface, In a cross section perpendicular to the axial direction and intersecting the first flange portion, The second opposing surface is provided with a convex portion having a convex shape that is convex toward the first flange portion when viewed from the axial direction, The first opposing surface is provided with a concave portion having a concave shape corresponding to the convex shape of the convex portion of the top plate, The second opposing surface has a notch on at least one of both ends in a direction perpendicular to the axial direction and parallel to the top surface of the top plate, When viewed along the axial direction, the notch has an inner top surface parallel to the top surface and an inner side surface perpendicular to the top surface and extending in a direction from the top plate toward the core, The coil component, wherein the cutout overlaps with the recess of the first flange portion when viewed from a direction perpendicular to the top surface of the top plate.

Images