Coil component

Abstract

Provided is a coil component capable of improving a Q value. The coil component includes: a core including a winding core portion, a first flange portion provided at a first end of the winding core portion, and a second flange portion provided at a second end of the winding core portion; a first external electrode provided at the first flange portion; a second external electrode provided at the second flange portion; and a wire wound around the winding core portion and electrically connected to the first external electrode and the second external electrode. The winding core portion has a peripheral surface extending in a circumferential direction centered on an axis of the winding core portion. In a cross section of the winding core portion including the axis, a distance between the peripheral surface and the axis at a central side in an axial direction of the winding core portion is smaller than distances at a first end side and a second end side of the winding core portion, and a distance between the wire and the axis at the central side in the axial direction of the winding core portion is smaller than distances at the first end side and the second end side of the winding core portion.

Description

Technical Field

[0001] This disclosure relates to coil components. Background Technology

[0002] Conventionally, a component described in Japanese Utility Model Patent No. 3204112 (Patent Document 1) exists as a coil component. The coil component includes: a core having a winding core portion and a pair of flange portions provided at both ends of the winding core portion; external electrodes respectively provided at the pair of flange portions; and wire wound around the winding core portion, with both ends electrically connected to the external electrodes.

[0003] Patent Document 1: Japanese Utility Model Patent No. 3204112

[0004] However, in the aforementioned conventional coil components, the thickness of the core is constant in a direction orthogonal to both end faces of the core. Therefore, the wire wound around the core may interfere with the magnetic flux. Consequently, eddy current losses may occur due to magnetic flux interference, reducing the Q value. Summary of the Invention

[0005] Therefore, this disclosure provides a coil component capable of improving the Q value.

[0006] To address the aforementioned issues, a coil component according to one aspect of this disclosure comprises: a core including a winding core portion, a first flange portion disposed at a first end of the winding core portion, and a second flange portion disposed at a second end of the winding core portion; a first external electrode disposed at the first flange portion; a second external electrode disposed at the second flange portion; and a wire wound around the winding core portion and electrically connected to the first external electrode and the second external electrode. The winding core portion has a circumferential surface extending circumferentially about the axis of the winding core portion. In a cross-section of the winding core portion including the axis, the distance between at least a portion of the circumferential surface and the axis is smaller at the central side of the winding core portion near the axial direction than the distance between the winding core portion near the first end and the second end. Furthermore, the distance between the wire and the axis is smaller at the central side of the winding core portion near the axial direction than the distance between the winding core portion near the first end and the second end.

[0007] Here, the axis of the core portion refers to a straight line that passes through the center of the section with the smallest cross-sectional area in a section perpendicular to the first direction orthogonal to the end faces of the first and second ends of the core portion, and is parallel to the aforementioned first direction.

[0008] The axial center of the core refers to the center between the first end and the second end of the core in the axial direction. The central side of the core refers to the side where the center of the core is located.

[0009] In at least a portion of the cross-section of the core containing the axis, the distance near the central side of the core is smaller than the distance near the first and second ends of the core.

[0010] According to the above embodiment, in the cross-section of the core including the axis, the distance between the circumferential surface and the axis is smaller at the central side of the core than at the first and second ends. Therefore, the circumferential surface of the core can be shaped to flow along the magnetic flux, and the wire wound around the circumferential surface of the core can be shaped to flow along the magnetic flux. As a result, magnetic flux interference can be reduced in the portions of the wire wound around the core near the first and second ends, thereby reducing eddy current losses caused by magnetic flux interference and improving the Q value.

[0011] Preferably, in one embodiment of the coil component, the peripheral surface of the core portion is composed of a plurality of surfaces arranged circumferentially along the axis of the core portion, and the distance between at least one of the plurality of surfaces and the axis is smaller at the central side of the axial direction of the core portion than the distance between the first end side and the second end side of the core portion.

[0012] According to the above embodiment, the peripheral surface of the core portion is composed of multiple surfaces, so that the wound wire is caught at the edge of the surface, which can suppress wire misalignment. Therefore, the wire can be reliably shaped to allow magnetic flux to flow along the peripheral surface of the core portion, and magnetic flux interference can be effectively reduced.

[0013] Preferably, in one embodiment of the coil component, the at least one surface includes: a first inclined portion whose distance from itself to the axis decreases continuously from the first end side toward the central side and from itself to the axis; and a second inclined portion whose distance from itself to the axis decreases continuously from the second end side toward the central side.

[0014] According to the above embodiment, at least one peripheral surface includes first and second inclined portions, thus enabling the peripheral surface of the core portion to be shaped to further flow along the magnetic flux. Therefore, the Q value can be further improved.

[0015] Preferably, in one embodiment of the coil component, the first inclined portion and the second inclined portion are planar, and the inclination angle of each of the first inclined portion and the second inclined portion relative to a straight line parallel to the axis is greater than 0° and less than 30°.

[0016] Here, the tilt angle of the first and second inclined parts is the angle when the first and second inclined parts are parallel to a straight line parallel to the axis, which is set to 0°.

[0017] According to the above embodiment, the tilt angles of the first and second tilted portions are each greater than 0° and less than 30°, thus enabling the circumferential surface of the core portion to form a shape that further flows along the magnetic flux. Therefore, the Q value can be further improved.

[0018] In one preferred embodiment of the coil component, the at least one surface includes the first inclined portion, the second inclined portion, and a horizontal portion connected between the first inclined portion and the second inclined portion and parallel to the axis. The wire is wound around the first inclined portion and the second inclined portion with one or more turns, and wound around the horizontal portion with two or more turns.

[0019] According to the above embodiment, the wire wound around the periphery of the core can be shaped to flow along the magnetic flux, which can further improve the Q value.

[0020] Preferably, in one embodiment of the coil component, all the aforementioned surfaces include the first inclined portion, the second inclined portion, and the horizontal portion.

[0021] According to the above embodiment, the wire wound around the periphery of the core can be shaped to flow along the magnetic flux, which can further improve the Q value.

[0022] Preferably, in one embodiment of the coil component, all the aforementioned surfaces are composed of the first inclined portion and the second inclined portion.

[0023] According to the above embodiment, the peripheral surface of the core portion can be made into a shape that flows along the magnetic flux, and the wire wound around the peripheral surface of the core portion can be made into a shape that flows along the magnetic flux, thereby further improving the Q value.

[0024] Preferably, in one embodiment of the coil component, the inclination angle of the first inclined portion in at least one surface relative to a straight line parallel to the axis is different from the inclination angle of the first inclined portion in other surfaces relative to a straight line parallel to the axis, and the inclination angle of the second inclined portion in at least one surface relative to a straight line parallel to the axis is different from the inclination angle of the second inclined portion in other surfaces relative to a straight line parallel to the axis.

[0025] According to the above embodiment, the peripheral surface of the core portion can be adjusted to a shape that flows along the magnetic flux, and the wire wound around the peripheral surface of the core portion can be adjusted to a shape that flows along the magnetic flux, thereby further improving the Q value.

[0026] Preferably, in one embodiment of the coil component, the first flange portion and the second flange portion each have: an inner end face facing the core portion side, an outer end face facing the side opposite to the inner end face, a bottom surface connecting the inner end face and the outer end face and facing the mounting substrate side during installation, a top surface connecting the inner end face and the outer end face and facing the side opposite to the bottom surface, and two side surfaces connecting the inner end face and the outer end face and connecting the bottom surface and the top surface. The coil component further includes a resin member, which extends from the upper part of the first flange portion. In the height direction from the bottom surface to the top surface, the resin component covers the top surface side of the first flange, the second flange, the core portion, and the wire, respectively. When viewed from a direction orthogonal to the side surface of the first flange, the distance between the lower edge of the area of ​​the resin component covering the core portion and the wire and the extended surface formed by extending the bottom surface of the first flange portion is smaller at the center side of the core portion than the distance between the first end side and the second end side of the core portion.

[0027] According to the above embodiment, compared to the case where the lower edge of the resin member is parallel to the axis when viewed from a direction orthogonal to the side of the first flange, the contact area between the resin member and the wire can be reduced. Therefore, stray capacitance between the resin member and the wire can be reduced, and the Q value can be improved.

[0028] In a preferred embodiment of the coil component, when viewed from a direction orthogonal to the side surface of the first flange, the lower edge of the resin component includes: a first inclined edge whose distance between itself and the extended surface decreases continuously from the first end side toward the central side and the extended surface, and a second inclined edge whose distance between itself and the extended surface decreases continuously from the second end side toward the central side.

[0029] According to the above embodiment, the lower edge of the resin component includes first and second inclined edges, thus further reducing the contact area between the resin component and the wire. This further reduces stray capacitance between the resin component and the wire, thereby further improving the Q value.

[0030] In one preferred embodiment of the coil component, the peripheral surface of the winding core includes a bottom surface facing the mounting substrate side during installation and a top surface facing the side opposite to the bottom surface during installation. The top surface of the winding core includes a first inclined portion whose distance from itself to the axis decreases continuously from the first end side toward the central side and a second inclined portion whose distance from itself to the axis decreases continuously from the second end side toward the central side. When viewed from a direction orthogonal to the side surface of the first flange, the inclination angle of the first inclined edge relative to a straight line parallel to the axis is the same as or greater than the inclination angle of the first inclined portion relative to a straight line parallel to the axis, and the inclination angle of the second inclined edge relative to a straight line parallel to the axis is the same as or greater than the inclination angle of the second inclined portion relative to a straight line parallel to the axis.

[0031] Here, the inclination angles of the first and second hypotenuses are defined as 0° when the first and second hypotenuses are parallel to a straight line parallel to the axis.

[0032] According to the above embodiment, the tilt angle of the first inclined side is the same as or greater than the tilt angle of the first inclined portion, and the tilt angle of the second inclined side is the same as or greater than the tilt angle of the second inclined portion. Therefore, the contact area between the resin component and the wire can be further reduced. As a result, the stray capacitance between the resin component and the wire can be further reduced, and the Q value can be further improved.

[0033] Preferably, in one embodiment of the coil component, when viewed from a direction orthogonal to the top surface of the first flange and a direction orthogonal to the axis, the width of the resin member at the center side of the core portion is smaller than the width at the first end side and the second end side of the core portion in terms of the width in the direction orthogonal to the axis.

[0034] According to the above embodiment, when viewed from a direction orthogonal to the top surface of the first flange, the resin member forms a recess on the central side of the core portion, thus suppressing the increase in the width dimension of the coil component caused by the formation of the resin member.

[0035] Preferably, in one embodiment of the coil component, the core portion is symmetrical with respect to a plane orthogonal to the axis and passing through the center of the core portion.

[0036] Here, the plane passing through the center of the core includes not only the case where the plane passes strictly through the center of the core, but also the case where it passes through the area that is 10% of the distance between the center and the first and second ends, relative to the center.

[0037] According to the above embodiment, the core portion is surface-symmetrical, thus enabling the peripheral surface of the core portion to be shaped along the flow of magnetic flux, which can further improve the Q value.

[0038] According to one aspect of the present disclosure, the coil component can improve the Q value. Attached Figure Description

[0039] Figure 1 This is a perspective view from above showing the first embodiment of the coil component.

[0040] Figure 2 This is a bottom view of the coil components.

[0041] Figure 3 yes Figure 2 AA sectional view.

[0042] Figure 4 This is a three-dimensional view taken from above the core.

[0043] Figure 5 It is an LT sectional view including the axis of the core.

[0044] Figure 6 It is an LW sectional view including the axis of the core.

[0045] Figure 7A It is a coordinate graph showing the relationship between frequency and L value with and without the tilted part.

[0046] Figure 7B It is a coordinate graph showing the relationship between frequency and Q value with and without the tilt.

[0047] Figure 8 It is a coordinate graph showing the relationship between frequency and Q value under the condition of the tilt angle of the tilted part.

[0048] Figure 9 This is a side view showing the second embodiment of the coil component.

[0049] Figure 10 This is a side view showing the third embodiment of the coil component.

[0050] Figure 11 This is a side view showing the third embodiment of the coil component.

[0051] Figure 12A It is a coordinate graph showing the relationship between frequency and Q value under the condition of the tilt angle of the tilted side.

[0052] Figure 12B yes Figure 12A An enlarged view of part B.

[0053] Figure 13This is a side view showing the fourth embodiment of the coil component.

[0054] Explanation of reference numerals in the attached figures

[0055] 1, 1A, 1B, 1C...coil components; 10, 10A...core; 11...first flange; 111...inner end face; 112...outer end face; 113...bottom surface; 114...top surface; 115...first side surface; 116...second side surface; 12...second flange; 121...inner end face; 122...outer end face; 123...bottom surface; 124...top surface; 125...first side surface; 126...second side surface; 13, 13A...winding core; 13a...axis; 13b...center; 130...circumferential surface; 131...first end; 132...second end; 133...bottom surface; 134...top surface; 135...first side surface Surface; 136...Second side surface; 15, 15B, 15C...Resin component; 150...Lower edge; 151...First bevel; 152...Second bevel; 20...Wire; 21...First lead-out; 22...Second lead-out; 31...First external electrode; 32...Second external electrode; 51...First inclined portion; 52...Second inclined portion; 53...Horizontal portion; c1~c3...Distance; d1~d3...Distance; e1~e3...Distance; h1~h3...Width; L1~L5...Straight line; S...Extended surface; θ1...First inclined angle; θ2...Second inclined angle; α1...First inclined angle; α2...Second inclined angle. Detailed Implementation

[0056] Hereinafter, a coil component according to one aspect of the present disclosure will be described in detail with reference to the illustrated embodiments. Note that some parts of the drawings are schematic and may not reflect actual dimensions or proportions.

[0057] <First Embodiment>

[0058] [Overview Structure]

[0059] Figure 1 This is a perspective view from above showing the first embodiment of the coil component. Figure 2 This is a bottom view of the coil components. Figure 3 yes Figure 2 AA sectional view. For example... Figure 1 , Figure 2 , Figure 3As shown, the coil component 1 includes: a core 10, a first external electrode 31 and a second external electrode 32 disposed on the core 10, a wire 20 wound on the core 10 and electrically connected to the first external electrode 31 and the second external electrode 32, and a resin component 15 mounted on the core 10.

[0060] The core 10 includes: a core portion 13, which is shaped to extend in a predetermined direction and on which wire 20 is wound; a first flange portion 11, which is provided at a first end 131 in the extending direction of the core portion 13 and extends in a direction orthogonal to that direction; and a second flange portion 12, which is provided at a second end 132 in the extending direction of the core portion 13 and extends in a direction orthogonal to that direction. The extending direction of the core portion 13 is also referred to as the axial direction 13a of the core portion 13. As a material for the core 10, non-magnetic materials such as alumina and resin are preferred, but magnetic materials such as sintered ferrite bodies and molded resin bodies containing magnetic powder can also be used.

[0061] Hereinafter, the bottom surface of the core 10 is designated as the surface on which it is mounted to the mounting substrate, and the surface opposite to the bottom surface of the core 10 is designated as the top surface of the core 10. The direction along the axis 13a of the winding core 13, extending from the first flange 11 towards the second flange 12, is defined as the L direction. The direction perpendicular to the L direction on the bottom surface of the core 10 is defined as the W direction, and the direction from the bottom surface of the core 10 towards the top surface is defined as the T direction. The T direction is perpendicular to both the L and W directions. When arranged in the order of W, L, and T, a right-hand rule is formed. The positive direction of the T direction is designated as "up," and the negative direction of the T direction is designated as "down." In other words, the bottom surface of the core 10 corresponds to "down" in the vertical direction, and the top surface of the core 10 corresponds to "up" in the vertical direction. The L direction is also referred to as the length direction of the core 10, the W direction as the width direction of the core 10, and the T direction as the height direction of the core 10.

[0062] A first external electrode 31 is disposed on the bottom surface of the first flange portion 11, and a second external electrode 32 is disposed on the bottom surface of the second flange portion 12. Both the first external electrode 31 and the second external electrode 32 have a base layer forming a substrate and a metal film disposed on the base layer. The base layer is formed, for example, by drying and firing silver paste. The metal film is, for example, a nickel alloy-based plating film deposited on the base layer by electroplating or the like.

[0063] The wire 20 is an insulating wire made of a metal such as copper, covered with a film made of a resin such as polyurethane or polyamide-imide. One end of the wire 20 is electrically connected to the first external electrode 31, and the other end is electrically connected to the second external electrode 32. The wire 20 and the first external electrode 31 are connected, for example, by hot pressing, brazing, or fusion welding. The wire 20 has a first lead-out portion 21 extending from the portion wound around the core portion 13 to the first external electrode 31, and a second lead-out portion 22 extending from the portion wound around the core portion 13 to the second external electrode 32.

[0064] Preferably, when viewed from the bottom side of the core 10, the first lead-out portion 21 and the second lead-out portion 22 are symmetrical about the center 13b of the core portion 13 along the axis 13a. The center 13b of the core portion 13 is the center point of the core portion 13. Accordingly, the first lead-out portion 21 and the second lead-out portion 22 can be made to have the same length, which can reduce inconsistencies in the performance of the coil component 1.

[0065] Preferably, when viewed from the bottom side of the core 10 while wound on the core 13, the wire 20 is symmetrical with respect to the center 13b of the core 13. Therefore, the wire 20 is point-symmetrical when wound on the core 13, thus reducing inconsistencies in the performance of the coil 20.

[0066] The resin component 15 is mounted on the top surface of the core 10. Specifically, the resin component 15 covers the area of ​​the core 10 and the wire 20 on the side closer to the top surface than the axis 13a. In other words, the area on the top surface is not hollow, but is filled by the resin component 15. In other words, the recess formed by the peripheral surface 130 of the core portion 13 and the first flange portion 11 and the second flange portion 12 is filled by the resin component 15 on the side closer to the top surface than the axis 13a.

[0067] The resin component 15 is the part that is mechanically held when the coil component 1 is picked up using an installation machine, and protects the wire 20 during picking. The upper surface of the resin component 15 is flat, allowing for stable mechanical holding. The resin component 15 is made of, for example, acrylic resin. Alternatively, the resin component 15 may extend towards the bottom surface from the axis 13a.

[0068] The core portion 13 has a circumferential surface 130 extending circumferentially along the axis 13a of the core portion 13. For example... Figure 3As shown, in the cross section of the core portion 13 including the axis 13a, in terms of the distance between the peripheral surface 130 and the axis 13a, the distance at the center 13b side of the core portion 13 is smaller than the distance at the first end 131 side and the second end 132 side of the core portion 13. Furthermore, in terms of the distance between the wire 20 and the axis 13a, the distance at the center 13b side of the core portion 13 is smaller than the distance at the first end 131 side and the second end 132 side of the core portion 13.

[0069] Specifically, in the portion on the top side of the circumferential surface 130, the distance d3 between the circumferential surface 130 at the center 13b of the core portion 13 and the axis 13a is less than the distance d1 between the circumferential surface 130 at the first end 131 of the core portion 13 and the axis 13a, and less than the distance d2 between the circumferential surface 130 at the second end 132 of the core portion 13 and the axis 13a.

[0070] Furthermore, in the portion on the top surface side of the peripheral surface 130, the distance c3 between the wire 20 at the center 13b of the core portion 13 and the axis 13a is less than the distance c1 between the wire 20 at the first end 131 of the core portion 13 and the axis 13a, and less than the distance c2 between the wire 20 at the second end 132 of the core portion 13 and the axis 13a. The distance c1 is equal to the distance d1.

[0071] Furthermore, the portion on the bottom side of the circumferential surface 130 is the same as the portion on the top side of the circumferential surface 130.

[0072] in addition, Figure 3 In the LT section of the core portion 13 including the axis 13a, the above-mentioned distance relationship is satisfied. However, in at least a portion of the section of the core portion 13 including the axis 13a, and in at least a local portion of the circumferential surface 130, the distance at the central 13b side of the core portion 13 is less than the distance at the first end 131 side and the second end 132 side of the core portion 13.

[0073] According to the above structure, in the cross section of the core portion 13 including the axis 13a, the distance between the peripheral surface 130 and the axis 13a is smaller at the center 13b side of the core portion 13 than at the first end 131 side and the second end 132 side of the core portion 13. Furthermore, the distance between the wire 20 and the axis 13a is smaller at the center 13b side of the core portion 13 than at the first end 131 side and the second end 132 side of the core portion 13. Therefore, the peripheral surface 130 of the core portion 13 can be made into a shape that flows along the magnetic flux, and the wire 20 wound on the peripheral surface 130 of the core portion 13 can be made into a shape that flows along the magnetic flux. Figure 3In the diagram, the dashed arrow B represents the flow of magnetic flux. As a result, in the portion of the wire 20 wound around the core portion 13 near the first end 131 and the second end 132 of the core portion 13, interference with magnetic flux can be reduced. Consequently, eddy current losses caused by interference with magnetic flux can be reduced, thereby increasing the Q value.

[0074] Here, as a method for obtaining the characteristic value, i.e., the Q value, which affects frequency matching in the winding design, one can cite the following: Based on the relationship derived from the Q value (Q=2πFL / [Rdc+Rac]), suppress the iron loss (Rac) caused by the thickening of the wire and increase the inductance value (L=kμN) caused by the thickening of the winding core. 2 S / W, S: cross-sectional area of ​​the core section, W: winding width of the wire relative to the core section).

[0075] However, increasing the wire thickness leads to a decrease in inductance due to the increased winding width of the wire relative to the core, while increasing the core thickness leads to an increase in copper loss (Rdc = ρE / S, E: wire length) due to the increased wire length. The thickening of the wire and the core are mutually compensating. Therefore, it is difficult to ensure a stable inductance and improve the Q value, and the thickening of both the wire and the core may limit the size of the coil components.

[0076] Therefore, in this embodiment, by adopting the above-described structure, interference from the magnetic flux of the wire 20 can be reduced. As a result, eddy current losses caused by magnetic flux interference can be reduced, thereby reducing the loss components caused by the wire 20. Since the iron loss (Rac) caused by the loss components is inversely proportional to the Q value, iron loss can be reduced, thus increasing the Q value. Furthermore, interference from magnetic flux on the wire 20 can be reduced, thus suppressing the decrease in inductance. Moreover, regardless of the thickness of the wire 20 and the core portion 13, the inductance value can be maintained and the Q value increased; therefore, there is no concern about the size of the coil component 1 being limited.

[0077] [Preferred structure of the core]

[0078] Figure 4 This is a three-dimensional view taken from above the core 10. Figure 5 This is an LT sectional view of the core 10 including axis 13a. Figure 6 It is an LW sectional view of the core 10 including axis 13a. Figure 5 and Figure 6 For convenience, the section lines are not labeled in the middle section view.

[0079] like Figure 4As shown, the peripheral surface 130 of the core portion 13 has: a bottom surface 133 facing the mounting substrate side during installation, a top surface 134 facing the side opposite to the bottom surface 133, and two side surfaces 135 and 136 connecting the bottom surface 133 and the top surface 134. The first side surface 135 is located in the positive direction of the W direction, and the second side surface 136 is located in the negative direction of the W direction. The bottom surface 133, the first side surface 135, the top surface 134, and the second side surface 136 are arranged circumferentially around the axis 13a of the core portion 13. In addition, the peripheral surface 130 is composed of four surfaces, but the peripheral surface 130 can be composed of three or more surfaces. According to the above structure, the peripheral surface 130 of the core portion 13 is composed of multiple surfaces 133, 134, 135, and 136, so that the wound wire 20 can be caught at the edge of the surface, and the misalignment of the wire 20 can be suppressed. Therefore, the wire 20 can be reliably shaped to allow the magnetic flux to flow along the circumferential surface 130 of the core portion 13, and the interference of the magnetic flux can be effectively reduced.

[0080] Preferably, the core portion 13 is symmetrical with respect to a plane orthogonal to the axis 13a and passing through the center 13b of the core portion 13. According to the above structure, the core portion 13 is surface-symmetrical, thus enabling the peripheral surface 130 of the core portion 13 to be shaped along the flow of magnetic flux, further improving the Q value.

[0081] The first flange portion 11 has: an inner end face 111 facing the core portion 13 side, an outer end face 112 facing the side opposite to the inner end face 111, a bottom surface 113 connecting the inner end face 111 and the outer end face 112 and facing the mounting substrate side during installation, a top surface 114 facing the side opposite to the bottom surface 113, and two first side surfaces 115 and second side surfaces 116 connecting the inner end face 111 and the outer end face 112 and connecting the bottom surface 113 and the top surface 114.

[0082] The second flange portion 12 has: an inner end face 121 facing the core portion 13, an outer end face 122 facing the opposite side of the inner end face 121, a bottom surface 123 facing the mounting substrate side during installation, a top surface 124 facing the opposite side of the bottom surface 123, and two first side surfaces 125 and second side surfaces 126 connecting the inner end face 121 and the outer end face 122 and connecting the bottom surface 123 and the top surface 124.

[0083] like Figure 5 As shown, the distance between the top surface 134 and the axis 13a is smaller at the center 13b side of the core portion 13 than at the first end 131 side and the second end 132 side of the core portion 13. According to the above structure, as described above, the peripheral surface 130 of the core portion 13 can be shaped to flow along the magnetic flux, and as a result, the Q value can be improved.

[0084] Furthermore, the distance between wire 20 and axis 13a has the same relationship as the distance between top surface 134 and axis 13a, and its explanation is omitted. The same applies to the following.

[0085] The top surface 134 includes a first inclined portion 51 whose distance from itself to the axis 13a continuously decreases from the first end 131 side toward the central 13b side, and a second inclined portion 52 whose distance from itself to the axis 13a continuously decreases from the second end 132 side toward the central 13b side. According to this structure, the peripheral surface 130 of the core portion 13 can be shaped to further flow along the magnetic flux. Therefore, the Q value can be further improved.

[0086] The first inclined portion 51 and the second inclined portion 52 are planar. Preferably, the first inclined angle θ1 formed by the first inclined portion 51 with respect to the first straight line L1 parallel to the axis 13a is greater than 0° and less than 30°. The second inclined angle θ2 formed by the second inclined portion 52 with respect to the first straight line L1 parallel to the axis 13a is preferably greater than 0° and less than 30°. The first inclined angle θ1 of the first inclined portion 51 and the second inclined angle θ2 of the second inclined portion 52 are the angles when the first and second inclined portions 51 and 52 are set to 0° when they are parallel to the first straight line L1.

[0087] According to the above structure, the first and second tilt angles θ1 and θ2 are greater than 0° and less than 30°, thus enabling the peripheral surface 130 of the core portion 13 to become a shape that further flows along the magnetic flux. Therefore, the Q value can be further improved. In addition, the first and second tilt portions 51 and 52 may not be planar, but curved surfaces. In this case, the tilt angle of the tilt portion refers to the tilt angle formed by the straight line connecting the first point closest to the axis 13a and the second point furthest from the axis 13a on the center line of the width direction (W direction) of the tilt portion, relative to the straight line parallel to the axis 13a.

[0088] In contrast, if the first and second tilt angles are 0°, the magnetic flux interference increases in the portions of the wire 20 wound around the core 13 near the first end 131 and the second end 132 of the core 13. As a result, eddy current losses caused by the magnetic flux interference increase, and the loss components in the wire 20 increase. On the other hand, if the tilt angles of the first and second tilt angles are greater than 30°, the magnetic flux interference increases in the portions of the wire 20 wound around the core 13 near the center 13b of the core 13. As a result, eddy current losses caused by the magnetic flux interference increase, and the loss components in the wire 20 increase.

[0089] Preferably, the first tilt angle θ1 and the second tilt angle θ2 are the same, and the first tilt portion 51 and the second tilt portion 52 intersect in a plane orthogonal to the axis 13a at the center 13b of the core portion 13. Thus, the first tilt portion 51 and the second tilt portion 52 are symmetrical with respect to the plane orthogonal to the axis 13a at the center 13b of the core portion 13, enabling the circumferential surface 130 of the core portion 13 to have a shape that flows along the magnetic flux.

[0090] like Figure 5 As shown, the bottom surface 133 has the same shape as the top surface 134. In other words, the distance between the bottom surface 133 and the axis 13a is smaller at the center 13b side of the core portion 13 than at the first end 131 side and the second end 132 side of the core portion 13. The bottom surface 133 includes a first inclined portion 51 whose distance from the axis 13a continuously decreases from the first end 131 side toward the center 13b side and a second inclined portion 52 whose distance from the axis 13a continuously decreases from the second end 132 side toward the center 13b side.

[0091] Furthermore, the first inclined portion 51 and the second inclined portion 52 are planar. The first inclined angle θ1 formed by the first inclined portion 51 with respect to the second straight line L2 parallel to the axis 13a is preferably greater than 0° and less than 30°. The second inclined angle θ2 formed by the second inclined portion 52 with respect to the second straight line L2 parallel to the axis 13a is preferably greater than 0° and less than 30°.

[0092] The first tilt angle θ1 in the bottom surface 133 is the same as the first tilt angle θ1 in the top surface 134, but they can also be different. In addition, the second tilt angle θ2 in the bottom surface 133 is the same as the second tilt angle θ2 in the top surface 134, but they can also be different.

[0093] like Figure 6 As shown, the first side surface 135 has the same shape as the top surface 134 and the bottom surface 133. In other words, the distance between the first side surface 135 and the axis 13a is smaller at the center 13b side of the core portion 13 than at the first end 131 side and the second end 132 side of the core portion 13. The first side surface 135 includes a first inclined portion 51 whose distance from the axis 13a continuously decreases from the first end 131 side toward the center 13b side and a second inclined portion 52 whose distance from the axis 13a continuously decreases from the second end 132 side toward the center 13b side.

[0094] Furthermore, the first inclined portion 51 and the second inclined portion 52 are planar. The first inclined angle θ1 formed by the first inclined portion 51 with respect to the third straight line L3 parallel to the axis 13a is preferably greater than 0° and less than 30°. The second inclined angle θ2 formed by the second inclined portion 52 with respect to the third straight line L3 parallel to the axis 13a is preferably greater than 0° and less than 30°.

[0095] The first tilt angle θ1 in the first side surface 135 is the same as the first tilt angle θ1 in the bottom surface 133 and the top surface 134, but it can also be different. In addition, the second tilt angle θ2 in the first side surface 135 is the same as the second tilt angle θ2 in the bottom surface 133 and the top surface 134, but it can also be different.

[0096] like Figure 6 As shown, the second side surface 136 has the same shape as the top surface 134 and the bottom surface 133. In other words, the distance between the second side surface 136 and the axis 13a is smaller at the center 13b side of the core portion 13 than at the first end 131 side and the second end 132 side of the core portion 13. The second side surface 136 includes a first inclined portion 51 whose distance from the axis 13a continuously decreases from the first end 131 side toward the center 13b side and a second inclined portion 52 whose distance from the axis 13a continuously decreases from the second end 132 side toward the center 13b side.

[0097] Furthermore, the first inclined portion 51 and the second inclined portion 52 are planar. The first inclined angle θ1 formed by the first inclined portion 51 with respect to the fourth straight line L4 parallel to the axis 13a is preferably greater than 0° and less than 30°. The second inclined angle θ2 formed by the second inclined portion 52 with respect to the fourth straight line L4 parallel to the axis 13a is preferably greater than 0° and less than 30°.

[0098] The first tilt angle θ1 in the second side 136 is the same as the first tilt angle θ1 in the first side 135, but they can also be different. In addition, the second tilt angle θ2 in the second side 136 is the same as the second tilt angle θ2 in the first side 135, but they can also be different.

[0099] like Figure 5 and Figure 6As shown, all surfaces constituting the peripheral surface 130 (bottom surface 133, top surface 134, first side surface 135, and second side surface 136) are formed by the first inclined portion 51 and the second inclined portion 52. According to the above structure, the peripheral surface 130 of the core portion 13 can be shaped to flow along the magnetic flux, and the wire 20 wound on the peripheral surface 130 of the core portion 13 can be shaped to flow along the magnetic flux, further improving the Q value. Furthermore, it is sufficient that at least one surface is formed by the first inclined portion 51 and the second inclined portion 52. In other words, regarding the distance between at least one surface and the axis 13a, it is sufficient that the distance at the center 13b side of the core portion 13 is less than the distance at the first end 131 side and the second end 132 side of the core portion 13.

[0100] Preferably, the first tilt angle formed by the first tilt portion 51 in at least one face with respect to a straight line parallel to the axis 13a is different from the first tilt angle formed by the first tilt portion 51 in other faces with respect to a straight line parallel to the axis 13a, and the second tilt angle formed by the second tilt portion 52 in at least one face with respect to a straight line parallel to the axis 13a is different from the second tilt angle formed by the second tilt portion 52 in other faces with respect to a straight line parallel to the axis 13a. According to the above structure, the peripheral surface 130 of the core portion 13 can be adjusted to a shape that flows along the magnetic flux, and the wire 20 wound on the peripheral surface 130 of the core portion 13 can be adjusted to a shape that flows along the magnetic flux, thereby further improving the Q value.

[0101] [Manufacturing method for coil components]

[0102] First, an alumina-based powder is prepared to form the core material, and this powder is filled into a female mold. Then, the powder is pressed and molded using a male mold to create a core with a core portion and a flange portion. At this point, the core portion is contracted from both ends toward the center, forming an inclined surface on its circumference. The core is then fired and hardened.

[0103] Next, an external electrode is formed on the flange portion of the core. Specifically, the bottom surface of the flange portion of the core is immersed in a container filled with Ag paste, allowing the Ag paste to adhere to the bottom surface of the flange portion of the core. Subsequently, the adhered Ag paste is dried and fired to form an Ag film that serves as the substrate for the external electrode. Next, a Ni alloy-based metal film is formed on the Ag film using methods such as electroplating. Through the above processes, the external electrode is formed.

[0104] Next, wire is wound onto the core portion of the core. During winding, a predetermined amount of wire is drawn out from the core portion at both ends of the wire. The portion drawn out from the core portion is then connected to the external electrodes by heat pressing.

[0105] Next, a resin component is formed on the core. Specifically, the top surface of the core, where no external electrodes are formed, is partially immersed in a container filled with the resin component, causing the resin component to adhere to the top surface of the core. Subsequently, the attachment area is irradiated with ultraviolet light for an extended period, thereby curing the resin component so that it does not deform when picked up using installation machinery. Through the above processes, the coil assembly is completed.

[0106] [Example]

[0107] As an example, using Figure 1 The coil component shown is a comparative example, using a conventional coil component without a sloping portion on the circumferential surface of the core. Furthermore, the inductance (L) and Q values ​​of the embodiment and the comparative example were determined.

[0108] Figure 7A It is a coordinate graph showing the relationship between frequency and L value. Figure 7B This is a coordinate graph showing the relationship between frequency and Q value. Coordinate graph g1 represents the embodiment, and coordinate graph g0 represents the comparative example. Coordinate graph g1 is represented by solid lines, and coordinate graph g0 by dashed lines. Figure 7A In the diagram, coordinate graph g1 and coordinate graph g0 completely overlap.

[0109] like Figure 7A As shown, the L value in the embodiment is unchanged compared to the comparative example. To explain this, the cross-sectional area of ​​the wire and the components used are unchanged in the embodiment compared to the comparative example; therefore, the inductance value is almost unchanged. Thus, in the embodiment, the design retains the expandability of the wire and the core portion in order to obtain the Q value.

[0110] like Figure 7B As shown, the Q value of the embodiment is increased compared to the comparative example. To explain this, in the comparative example, magnetic flux interference at both ends of the core increases eddy current losses, thus increasing the loss component. On the other hand, in the embodiment, the shape of the core flows along the magnetic circuit; therefore, the wire arrangement follows the distribution of magnetic flux, suppressing eddy current losses caused by overlap between the wire and magnetic flux. Thus, compared to the comparative example, the embodiment reduces eddy current losses due to magnetic flux interference, reduces the loss component in the wire, and improves the Q value.

[0111] Figure 8This illustrates the relationship between frequency and Q value resulting from different tilt angles of the inclined portion. Coordinate graphs g21, g22, g23, and g24 represent the embodiments, while coordinate graph g0 represents the comparative example. Coordinate graph g21 is represented by a solid line, coordinate graph g22 by a single-dotted line, coordinate graph g23 by a double-dotted line, coordinate graph g24 by a triple-dotted line, and coordinate graph g0 by a dashed line.

[0112] In coordinate graph g21, the Q value is represented when the first tilt angle θ1 and the second tilt angle θ2 of the bottom surface, top surface, first side surface and second side surface of the core are 30°.

[0113] In coordinate graph g22, the Q value is represented when the first tilt angle θ1 and the second tilt angle θ2 of the bottom surface, top surface, first side surface and second side surface of the core are 15°.

[0114] In coordinate graph g23, the Q value is represented when the first tilt angle θ1 and the second tilt angle θ2 of the bottom surface, top surface, first side surface and second side surface of the core are 10°.

[0115] In coordinate graph g24, the Q value is represented when the first tilt angle θ1 and the second tilt angle θ2 of the bottom surface, top surface, first side surface, and second side surface of the core are 5°.

[0116] In coordinate graph g0, Q values ​​are represented when the first tilt angle θ1 and the second tilt angle θ2 of the bottom surface, top surface, first side surface, and second side surface of the core are 0°.

[0117] like Figure 8 As shown, the Q value increases in the order of coordinate graphs g0, g24, g23, g22, and g21. For example, at a frequency of 2 GHz, the Q value of coordinate graph g0 is 72.79, the Q value of coordinate graph g24 is 77.52, the Q value of coordinate graph g23 is 82.661, the Q value of coordinate graph g22 is 85.538, and the Q value of coordinate graph g21 is 88.375. In this case, regarding the quality of the Q value, coordinate graph g0 has a low Q value and is not preferred, while coordinate graphs g24, g23, g22, and g21 have high Q values ​​and are preferred.

[0118] To explain this, as the tilt angle increases from 0° to 30°, the circumferential surface of the core approaches a shape that flows along the magnetic flux. This reduces the likelihood of the magnetic flux interfering with the wire, thus decreasing eddy current losses caused by magnetic flux interference and reducing loss components in the wire, thereby improving the Q value. Conversely, if the tilt angle exceeds 30°, the magnetic flux easily interferes with the wire on the central side of the core. This results in increased eddy current losses due to magnetic flux interference, increased loss components in the wire, and a decreased Q value. Therefore, a tilt angle greater than 0° and less than 30° is preferable to improve the Q value.

[0119] In addition, if the tilt angle exceeds 40°, the wire will slide on the circumference of the core when it is wound, making the winding of the wire difficult.

[0120] <Second Implementation>

[0121] Figure 9 This is a side view showing the second embodiment of the coil component. The shape of the core portion of the coil body in the second embodiment differs from that in the first embodiment. This difference in structure will be described below. The other structures are the same as those in the first embodiment, and the same reference numerals are used as in the first embodiment, with their descriptions omitted. Figure 9 For convenience, the resin component 15 is omitted from the drawing, and the wire 20 is drawn through the cross section.

[0122] like Figure 9 As shown, in the coil component 1A of the second embodiment, the top surface 134 and bottom surface 133 of the core portion 13A of the core 10A respectively include a first inclined portion 51, a second inclined portion 52, and a horizontal portion 53 connecting the first inclined portion 51 and the second inclined portion 52. The first inclined portion 51 and the second inclined portion 52 have the same structure as those described in the first embodiment. The horizontal portion 53 is a portion parallel to the axis 13a. The wire 20 is wound at least one turn on each of the first inclined portion 51 and the second inclined portion 52, and at least two turns on the horizontal portion 53. According to the above structure, the wire 20 wound on the peripheral surface 130 of the core portion 13A can be shaped to flow along the magnetic flux, which can further improve the Q value. In addition, by providing a horizontal portion 53 between the first inclined portion 51 and the second inclined portion 52, it is possible to suppress the unwinding of the wire 20 wound on the first inclined portion 51 and the second inclined portion 52.

[0123] Preferably, all surfaces of the peripheral surface 130 constituting the core portion 13A include a first inclined portion 51, a second inclined portion 52, and a horizontal portion 53. According to this structure, the wire 20 wound on the peripheral surface 130 of the core portion 13A can be shaped to flow along the magnetic flux, further improving the Q value. Furthermore, it is sufficient that at least one surface constituting the peripheral surface 130 is composed of the first inclined portion 51, the second inclined portion 52, and the horizontal portion 53.

[0124] <Third Implementation>

[0125] Figure 10 This is a side view showing the third embodiment of the coil component. The shape of the resin component in the third embodiment differs from that in the first embodiment. This difference in structure will be described below. Other structures are the same as those in the first embodiment, and are labeled with the same reference numerals as in the first embodiment, with their descriptions omitted.

[0126] like Figure 10 As shown, in the coil component 1B of the third embodiment, the resin component 15B covers the top surface area of ​​each of the first flange 11, the second flange 12, the core portion 13, and the wire 20 in the height direction (T direction). When viewed from a direction orthogonal to the first side surface 115 of the first flange 11, the resin component 15B has a lower edge 150 in the height direction in the area covering the core portion 13 and the wire 20. The extended surface S formed by extending the bottom surface 113 of the first flange 11 contacts the bottom surface 123 of the second flange 12.

[0127] When viewed from a direction orthogonal to the first side surface 115 of the first flange portion 11, the distance between the lower edge 150 and the extended surface S is smaller at the center 13b side of the core portion 13 than at the first end 131 side and the second end 132 side of the core portion 13. Specifically, when viewed from a direction orthogonal to the first side surface 115 of the first flange portion 11, the distance e3 between the lower edge 150 at the center 13b of the core portion 13 and the extended surface S is smaller than the distance e1 between the lower edge 150 at the first end 131 of the core portion 13 and the extended surface S, and smaller than the distance e2 between the lower edge 150 at the second end 132 of the core portion 13 and the extended surface S.

[0128] According to the above structure, compared to the case where the lower edge 150 is parallel to the axis 13a when viewed from a direction orthogonal to the first side surface 115 of the first flange portion 11, the contact area between the resin member 15B and the wire 20 can be reduced. This reduces stray capacitance between the resin member 15B and the wire 20, thereby improving the Q value. Specifically, the dielectric constant μ of the resin member 15B is higher than that of air; therefore, stray capacitance is generated between the resin member 15B and the wire 20. Reducing this stray capacitance results in a smaller stray capacitance C in the formula for the Q value (Q = 1 / R × √(L / C)), thus improving the Q value.

[0129] Preferably, when viewed from a direction orthogonal to the second side surface 116 of the first flange portion 11, the distance between the lower edge 150 and the extended surface S is smaller at the center 13b side of the core portion 13 than at the first end 131 side and the second end 132 side of the core portion 13. This further reduces stray capacitance between the resin member 15B and the wire 20, thereby improving the Q value.

[0130] Preferably, when viewed from a direction orthogonal to the first side surface 115 of the first flange portion 11, the lower edge 150 of the resin member 15B is located on the top surface side of the core 10, closer to the axis 13a. Accordingly, stray capacitance between the resin member 15B and the wire 20 can be further reduced, and the Q value can be further improved.

[0131] Figure 11 This is a side view showing the third embodiment of the coil component. Figure 11 Will Figure 10 The wire 20, the first external electrode 31 and the second external electrode 32 are omitted from the description. Figure 11 As shown, when viewed from a direction orthogonal to the first side surface 115 of the first flange portion 11, the lower edge 150 of the resin member 15B includes: a first inclined side 151 whose distance between itself and the extended surface S continuously decreases from the first end 131 side toward the central 13b side, and a second inclined side 152 whose distance between itself and the extended surface S continuously decreases from the second end 132 side toward the central 13b side. Preferably, when viewed from a direction orthogonal to the second side surface 116 of the first flange portion 11, the lower edge 150 of the resin member 15B includes the first inclined side 151 and the second inclined side 152.

[0132] According to the above structure, the lower edge 150 of the resin component 15B includes first and second inclined sides 151 and 152, thus further reducing the contact area between the resin component 15B and the wire 20. This further reduces the stray capacitance between the resin component 15B and the wire 20, thereby further improving the Q value. Alternatively, the lower edge 150 may include not only the first and second inclined sides 151 and 152, but also, for example, a horizontal side disposed between the first inclined side 151 and the second inclined side 152 and parallel to the axis 13a.

[0133] The first inclined portion 51 and the second inclined portion 52 are straight lines. When viewed from a direction orthogonal to the first side surface 115 of the first flange portion 11, the first inclined angle α1 formed by the first inclined side 151 with respect to the fifth straight line L5 parallel to the axis 13a is the same as or greater than the first inclined angle θ1 formed by the first inclined portion 51 with respect to the first straight line L1 parallel to the axis 13a, and the second inclined angle α2 formed by the second inclined side 152 with respect to the fifth straight line L5 parallel to the axis 13a is the same as or greater than the second inclined angle θ2 formed by the second inclined portion 52 with respect to the first straight line L1 parallel to the axis 13a. The first inclined angle α1 of the first inclined side 151 and the second inclined angle α2 of the second inclined side 152 are the angles when the first and second inclined sides 51 and 52 are respectively set to 0° when they are parallel to the first straight line L1.

[0134] According to the above structure, the first tilt angle α1 of the first inclined side 151 is the same as or greater than the first tilt angle θ1 of the first inclined portion 51, and the second tilt angle α2 of the second inclined side 152 is the same as or greater than the second tilt angle θ2 of the second inclined portion 52. Therefore, the contact area between the resin component 15B and the wire 20 can be further reduced. As a result, the stray capacitance between the resin component 15B and the wire 20 can be further reduced, and the Q value can be further improved.

[0135] Preferably, the first tilt angle α1 of the first inclined side 151 is greater than the first tilt angle θ1 of the first inclined portion 51, and the second tilt angle α2 of the second inclined side 152 is greater than the second tilt angle θ2 of the second inclined portion 52. Accordingly, the contact area between the resin component 15B and the wire 20 can be further reduced.

[0136] In addition, the first and second hypotenuses 151 and 152 may be curves instead of straight lines. In this case, the inclination angle of the hypotenuse refers to the inclination angle of the straight line connecting the first point closest to the extended surface S and the second point furthest from the extended surface S when viewed from a direction orthogonal to the side of the flange, relative to the straight line parallel to the axis 13a.

[0137] Figure 12A It is a coordinate graph showing the relationship between frequency and Q value. Figure 12B yes Figure 12A Enlarged view of Part B. Coordinate graphs g41 and g42 represent the embodiments, and coordinate graph g5 represents the reference example. Coordinate graph g41 is represented by solid lines, coordinate graph g42 by dashed lines, and coordinate graph g5 by dashed lines. Coordinate graphs g41 and g42 overlap except in certain areas, and coordinate graphs g41 and g5 overlap except in certain areas.

[0138] In coordinate graph g41, the Q value represents the value when the first tilt angle α1 of the first inclined side 151 is greater than the first tilt angle θ1 of the first inclined portion 51 and the second tilt angle α2 of the second inclined side 152 is greater than the second tilt angle θ2 of the second inclined portion 52. In coordinate graph g42, the Q value represents the value when the first tilt angle α1 of the first inclined side 151 is the same as the first tilt angle θ1 of the first inclined portion 51 and the second tilt angle α2 of the second inclined side 152 is the same as the second tilt angle θ2 of the second inclined portion 52. In coordinate graph g5, the Q value represents the value when the core portion 13 has the first inclined portion 51 and the second inclined portion 52, but the lower edge 150 of the resin member 15B does not have the first tilt angle 151 and the second tilt angle 152 and is parallel to the axis 13a.

[0139] like Figure 12B As shown, at a frequency of 1 GHz, the Q values ​​of graphs g41 and g42 increase compared to graph g5. Furthermore, the Q value of graph g41 is slightly higher than that of graph g42.

[0140] Next, the method for forming the lower edge 150 of the resin component 15B will be described. In the steps from immersing the core in the resin component to curing the resin component with ultraviolet light, for example, the vertical movement of the lower edge of the resin component is suppressed by controlling the irradiation time and intensity of the ultraviolet light. Specifically, compared to the resin component at the center of the core, the resin component at the end of the core is irradiated with ultraviolet light earlier, or the intensity of the ultraviolet light is increased for the resin component at the end of the core compared to the resin component at the center of the core. This prevents the resin component from sagging off the entire core due to gravitational acceleration, allowing the resin component to sag only at the center of the core. Furthermore, the capillary effect between adjacent turns of wire allows the resin component at the center of the core to sag only. Thus, a first bevel and a second bevel can be formed at the lower edge of the resin component.

[0141] like Figure 10 and Figure 11As shown, preferably, the resin component 15B covers a portion of the outer end face 112, the first side face 115, and the second side face 116 of the first flange portion 11. This makes the resin component 15B less prone to peeling. Furthermore, the thickness of the resin component 15B decreases towards the bottom surface of the core 10 in the height direction. The thickness of the resin component 15B refers to the distance from the surface of the core 10 in contact with the resin component 15B to the surface of the resin component 15B. This reduces the amount of resin component 15B covering the wire 20, thereby reducing stray capacitance and improving the Q value.

[0142] <Fourth Implementation>

[0143] Figure 13 This is a side view showing the fourth embodiment of the coil component. The shape of the resin component in the fourth embodiment differs from that in the first embodiment. This difference in structure will be described below. The other structures are the same as those in the first embodiment, and the same reference numerals are used as in the first embodiment, with their descriptions omitted.

[0144] like Figure 13 As shown, in the coil component 1C of the fourth embodiment, when viewed from a direction orthogonal to the top surface 114 of the first flange portion 11, the width of the resin member 15C in the direction orthogonal to the axis 13a (W direction) is smaller at the center 13b side than at the first end 131 side and the second end 132 side of the core portion 13. Specifically, when viewed from a direction orthogonal to the top surface 114 of the first flange portion 11, the width h3 of the resin member 15C at the center 13b of the core portion 13 is smaller than the width h1 of the resin member 15C at the first end 131 of the core portion 13, and smaller than the width h2 of the resin member 15C at the second end 132 of the core portion 13. In other words, when viewed from the T direction, the side of the resin component 15C is shaped along the first side 135 (first and second inclined portions 51 and 52) and the second side 136 (first and second inclined portions 51 and 52) of the core portion 13.

[0145] According to the above structure, when viewed from a direction orthogonal to the top surface 114 of the first flange portion 11 and a direction orthogonal to the axis 13a, the resin member 15C forms a recess on the side of the center 13b of the core portion 13. Therefore, the increase in the width dimension of the coil member 1 caused by the formation of the resin member 15C can be suppressed. As a method for forming the side of the resin member 15C, the depth to which the core 10 is immersed in the resin member is made shallower, and the amount of resin member attached to the core 10 is controlled, thereby enabling the formation of a recess on the side of the resin member 15C.

[0146] Alternatively, a recess may be formed on the side of the resin member 15C in the coil member 1A of the second embodiment. In this case, when viewed from the T direction, the side of the resin member 15C has a shape along the first side 135 (first and second inclined portions 51, 52 and horizontal portion 53) and the second side 136 (first and second inclined portions 51, 52 and horizontal portion 53) of the core portion 13.

[0147] Furthermore, this disclosure is not limited to the embodiments described above, and design changes can be made without departing from the spirit of this disclosure. For example, the feature points of each of the first to fourth embodiments can be combined in various ways.

[0148] In the above embodiment, there is one wire and two external electrodes, but the number of wires and external electrodes can also be increased.

[0149] In the above embodiments, in a cross section orthogonal to the axis of the core portion, the shape of the circumference of the core portion is a quadrilateral, but it can also be a polygon such as a triangle or pentagon. In addition, it can be not only a polygon but also a circle or an ellipse.

[0150] In the above embodiments, the circumferential surface of the core portion includes an inclined portion, but may also include a stepped portion (referred to as a stepped portion) from the first end side (second end side) of the core portion toward the central side of the core portion itself and the axis, where the distance between the core portion and the axis decreases in a stepped manner.

[0151] In the above embodiments, the lower edge of the resin component includes a bevel, but may also include a stepped edge (called a stepped edge) from the first end side (second end side) of the core portion toward the central side of the core portion itself and the extended surface, where the distance between the two sides decreases in a stepped manner.

Claims

1. A coil component, characterized in that, have: The core includes a core portion, a first flange portion disposed at a first end of the core portion, and a second flange portion disposed at a second end of the core portion; The first external electrode is disposed on the first flange portion; A second external electrode, which is disposed on the second flange portion; and A wire, wound around the core portion and electrically connected to the first external electrode and the second external electrode. The core portion has a circumferential surface extending circumferentially along the axis of the core portion. In the cross-section of the core portion including the axis, with respect to the distance between at least a portion of the circumferential surface and the axis, the axial distance at the central side of the core portion is smaller than the distance between the first end side and the second end side of the core portion; and, with respect to the distance between the wire and the axis, the axial distance at the central side of the core portion is smaller than the distance between the first end side and the second end side of the core portion. The first flange portion and the second flange portion each have: an inner end face facing the core portion side, an outer end face facing the side opposite to the inner end face, a bottom surface connecting the inner end face and the outer end face and facing the mounting substrate side during installation, a top surface connecting the inner end face and the outer end face and facing the side opposite to the bottom surface during installation, and two side surfaces connecting the inner end face and the outer end face and connecting the bottom surface and the top surface. It also includes a resin component that covers all of the top surface side and a portion of the side surface side of each of the first flange portion, the second flange portion, the core portion, and the wire in a height direction from the bottom surface of the first flange portion toward the top surface. When viewed from a direction orthogonal to the side surface of the first flange, the distance at the center side of the core portion is less than the distance at the first end side and the second end side of the core portion in terms of the distance between the lower edge of the region of the resin member covering the side surface of the core portion and the side surface of the wire and the extended surface formed by extending the bottom surface of the first flange portion.

2. The coil component according to claim 1, characterized in that, The circumferential surface of the core portion is composed of a plurality of surfaces arranged circumferentially around the axis of the core portion. With regard to the distance between at least one of the plurality of faces and the axis, the distance at the central side of the axial direction of the core portion is less than the distance at the first end side and the second end side of the core portion.

3. The coil component according to claim 2, characterized in that, The at least one surface includes: a first inclined portion whose distance from itself to the axis decreases continuously from the first end side toward the central side, and a second inclined portion whose distance from itself to the axis decreases continuously from the second end side toward the central side.

4. The coil component according to claim 3, characterized in that, The first inclined portion and the second inclined portion are planar. The first inclined portion and the second inclined portion are respectively inclined at an angle greater than 0° and less than 30° relative to a straight line parallel to the axis.

5. The coil component according to claim 3 or 4, characterized in that, The at least one surface includes the first inclined portion, the second inclined portion, and a horizontal portion connecting the first inclined portion and the second inclined portion and parallel to the axis. The wire is wound around the first inclined portion and the second inclined portion with one or more turns, and wound around the horizontal portion with two or more turns.

6. The coil component according to claim 5, characterized in that, All of the aforementioned surfaces include the first inclined portion, the second inclined portion, and the horizontal portion.

7. The coil component according to claim 3 or 4, characterized in that, All of the aforementioned surfaces are formed by the first inclined portion and the second inclined portion.

8. The coil component according to claim 6, characterized in that, The angle of inclination of the first inclined portion in at least one face relative to a straight line parallel to the axis is different from the angle of inclination of the first inclined portion in the other faces relative to a straight line parallel to the axis. The angle of inclination of the second inclined portion in at least one face relative to a straight line parallel to the axis is different from the angle of inclination of the second inclined portion in the other faces relative to a straight line parallel to the axis.

9. The coil component according to claim 1, characterized in that, When viewed from a direction orthogonal to the side surface of the first flange, the lower edge of the resin member includes: a first inclined side whose distance between itself and the extended surface decreases continuously from the first end side toward the central side, and a second inclined side whose distance between itself and the extended surface decreases continuously from the second end side toward the central side.

10. The coil component according to claim 9, characterized in that, The peripheral surface of the core portion includes: a bottom surface facing the mounting substrate side during installation and a top surface facing the side opposite to the bottom surface. The top surface of the core portion includes: a first inclined portion whose distance from itself to the axis continuously decreases from the first end side toward the central side, and a second inclined portion whose distance from itself to the axis continuously decreases from the second end side toward the central side. When viewed from a direction orthogonal to the side of the first flange, the angle of inclination of the first inclined side relative to a straight line parallel to the axis is the same as or greater than the angle of inclination of the first inclined portion relative to a straight line parallel to the axis, and the angle of inclination of the second inclined side relative to a straight line parallel to the axis is the same as or greater than the angle of inclination of the second inclined portion relative to a straight line parallel to the axis.

11. The coil component according to claim 1, characterized in that, When viewed from a direction orthogonal to the top surface of the first flange, the width of the resin member at the center of the core portion is smaller than the width at the first end and the second end of the core portion in terms of the width of the core portion in a direction orthogonal to the axis.

12. The coil component according to any one of claims 1 to 4, characterized in that, The core portion is symmetrical with respect to a plane orthogonal to the axis and passing through the center of the core portion.

Images