COIL COMPONENT

A coil component includes a drum core including a winding core portion, first and second flange portions, a first metal terminal attached to the first flange portion, and a first wire. The first flange portion is connected to a first end of the winding core portion in a direction along a central axis of the winding core portion. A first connection end of the first wire is joined to the first metal terminal, which has a bonding portion that is fixed to an outer end surface. The bonding portion has a facing surface and a recess that is recessed with respect to the facing surface and accommodates an adhesive. When viewed in a direction along a central axis, an area of a region of the recess facing the outer end surface is equal to or larger than an area of the facing surface.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit of priority to Japanese Patent Application No. 2022-078361, filed May 11, 2022, the entire content of which is incorporated herein by reference.

BACKGROUND

Technical Field

The present disclosure relates to a coil component.

Background Art

The coil component described in Japanese Patent Application Laid-Open No. 2012-89804 includes a winding core portion and two flange portions. The winding core portion has a quadrangular prism shape. The two flange portions are connected to both ends of the winding core portion. Each flange portion protrudes outward from the winding core portion in a direction orthogonal to a central axis of the winding core portion. The material of the winding core portion and the flange portion is a magnetic material. The winding core portion and the flange portion constitute a core of the coil component.

The coil component includes a plurality of metal terminals and two wires. An end of each wire is joined to each metal terminal. When a surface of each flange portion on a side opposite to the winding core portion is defined as an outer end surface, each metal terminal is fixed to the outer end surface of each flange portion with an adhesive.

SUMMARY

In the coil component described in Japanese Patent Application Laid-Open No. 2012-89804, as the amount of the adhesive interposed between the metal terminal and the flange portion increases, improvement of the bonding strength of the metal terminal to the flange portion can be expected. However, simply increasing the amount of the adhesive causes the adhesive to protrude to an unintended portion when the metal terminal is attached to the flange portion. Therefore, only increasing the amount of the adhesive does not lead to improvement of the bonding strength of the metal terminal.

Accordingly, the present disclosure provides a coil component including a drum core including a columnar winding core portion, a first flange portion connected to a first end of the winding core portion in a direction along a central axis of the winding core portion, and a second flange portion connected to a second end of the winding core portion opposite to the first end; a first metal terminal attached to the first flange portion; and a wire wound around the winding core portion and having a first connection end joined to the first metal terminal. When a direction from the first metal terminal toward the winding core portion in a direction along the central axis is defined as an inward direction, and a direction opposite to the inward direction is defined as an outward direction, the first flange portion has an outer end surface facing the outward direction side, the first metal terminal includes a bonding portion fixed to the outer end surface, and the bonding portion has a facing surface facing the outer end surface from the outward direction side, and a recess recessed with respect to the facing surface and accommodating an adhesive. When viewed in a direction along the central axis, an area of a region of the recess facing the outer end surface is equal to or larger than an area of the facing surface.

In the above configuration, the area obtained by adding the area of the region facing the outer end surface of the recess and the area of the facing surface is the area of the region facing the outer end surface of the first flange portion in the first metal terminal. According to the above configuration, the area of the region of the recess facing the outer end surface occupies ½ or more of the region of the first metal terminal facing the outer end surface of the first flange portion. By providing the recess over a wide range as described above, if a large amount of adhesive is applied, it is possible to prevent the adhesive from protruding out of the range of the recess. Further, since a large amount of adhesive can be accommodated in the recess, it is possible to expect improvement in bonding strength of the first metal terminal to the first flange portion.

The bonding strength of the metal terminal in the coil component is improved.

DETAILED DESCRIPTION

Hereinafter, an embodiment of a coil component will be described. The drawings may show enlarged components to facilitate understanding. The dimensional ratios of the components may be different from the actual ones or those in another drawing.

As illustrated inFIG.1, a coil component10includes a drum core10C and a top plate12.

The drum core10C includes a winding core portion11, a first flange portion20, and a second flange portion30.

The winding core portion11has a quadrangular prism shape. The material of the winding core portion11is a non-conductive material. Specifically, the material of the winding core portion11can be, for example, alumina, Ni—Zn-based ferrite, resin, a mixture thereof, or the like.

The first flange portion20is connected to a first end of the winding core portion11in a direction along a central axis C. The second flange portion30is connected to a second end of the winding core portion11in the direction along the central axis C. The material of the first flange portion20and the second flange portion30is the same non-conductive material as the winding core portion11. The first flange portion20and the second flange portion30are integrally molded with the winding core portion11.

Here, a specific axis orthogonal to the central axis C is defined as a first axis X. In the present embodiment, the first axis X is parallel to two of the four sides of the winding core portion11when viewed in the direction along the central axis C. An axis orthogonal to both the central axis C and the first axis X is defined as a second axis Y. Further, in the present embodiment, an axis parallel to the central axis C is defined as a third axis Z. One of the directions along the first axis X is defined as a first positive direction X1, and a direction opposite to the first positive direction X1is defined as a first negative direction X2. Similarly, one of the directions along the second axis Y is defined as a second positive direction Y1, and a direction opposite to the second positive direction Y1is defined as a second negative direction Y2. One of the directions along the third axis Z is defined as a third positive direction Z1, and a direction opposite to the third positive direction Z1is defined as a third negative direction Z2. In the present embodiment, a direction from the winding core portion11toward the first flange portion20is defined as a third positive direction Z1, and a direction from the winding core portion11toward the second flange portion30is defined as a third negative direction Z2.

The first flange portion20protrudes outward with respect to the winding core portion11in the direction along the first axis X and the direction along the second axis Y. The first flange portion20has a symmetrical shape in the direction along the second axis Y. The first flange portion20has an outer end surface20A. The outer end surface20A is a surface facing the third positive direction Z1side among the outer surfaces of the first flange portion20.

The first flange portion20includes a main body portion21and a protruding portion22. The main body portion21has a quadrangular prism shape that is flat in the direction along the third axis Z as a whole. When viewed in the third negative direction Z2, the edge of the main body portion21on the first negative direction X2side is parallel to the second axis Y. When viewed in the third negative direction Z2, the edge of the main body portion21on the first positive direction X1side is parallel to the second axis Y. Therefore, the main body portion21has an upper surface21A facing the first positive direction X1side.

The protruding portion22protrudes from the upper surface21A of the main body portion21toward the first positive direction X1. The protruding portion22has a quadrangular frustum shape in which the dimension in the direction along the second axis Y decreases toward the first positive direction X1. The protruding portion22is located substantially at the center of the main body portion21in the direction along the second axis Y. The dimension of the protruding portion22in the direction along the third axis Z is the same as the dimension of the main body portion21in the direction along the third axis Z.

The protruding portion22has an upper end surface22A and two side surfaces22B. The upper end surface22A is a surface facing the first positive direction X1side among the outer surfaces of the protruding portion22. Each of the side surfaces22B is a surface connecting the upper end surface22A and the upper surface21A of the main body portion21. One of the side surfaces22B faces the second positive direction Y1side. The other one of the side surfaces22B faces the second negative direction Y2side. The main body portion21and the protruding portion22are integrally molded. That is, there is no clear boundary between the main body portion21and the protruding portion22inside the first flange portion20.

The second flange portion30has a symmetrical shape with respect to the first flange portion20in the direction along the third axis Z. That is, the second flange portion30protrudes outward with respect to the winding core portion11in the direction along the first axis X and the direction along the second axis Y. The second flange portion30has an outer end surface30A. The outer end surface30A is a surface facing the third negative direction Z2side among the outer surfaces of the second flange portion30. The second flange portion30includes a main body portion31and a protruding portion32. The configurations of the main body portion31and the protruding portion32are similar to those of the main body portion21and the protruding portion22of the first flange portion20. That is, the main body portion31has an upper surface31A facing the first positive direction X1side. The protruding portion32has an upper end surface32A and two side surfaces32B.

In the present embodiment, the maximum dimension of the drum core10C in the direction along the first axis X is 1.4 mm. The maximum dimension of the drum core10C in the direction along the second axis Y is 2.5 mm. The maximum dimension of the drum core10C in the direction along the third axis Z is 3.2 mm.

The top plate12has a rectangular plate shape. The top plate12is flat in the direction along the first axis X. The long side of the top plate12is parallel to the third axis Z. The short side of the top plate12is parallel to the second axis Y. The top plate12is located on the first negative direction X2side with respect to the drum core10C. The top plate12is connected to both the surface of the first flange portion20facing the first negative direction X2and the surface of the second flange portion30facing the first negative direction X2. That is, the top plate12is bridged between the first flange portion20and the second flange portion30. The material of the top plate12is the same non-conductive material as that of the drum core10C.

The coil component10includes a first metal terminal41, a second metal terminal42, a third metal terminal43, and a fourth metal terminal44.

The first metal terminal41is attached to the first flange portion20. The first metal terminal41is located on the second positive direction Y1side with respect to the center of the first flange portion20in the direction along the second axis Y. The second metal terminal42is attached to the first flange portion20. The second metal terminal42is located on the second negative direction Y2side with respect to the center of the first flange portion20in the direction along the second axis Y. The third metal terminal43is attached to the second flange portion30. The third metal terminal43is located on the second positive direction Y1side with respect to the center of the second flange portion30in the direction along the second axis Y. The fourth metal terminal44is attached to the second flange portion30. The fourth metal terminal44is located on the second negative direction Y2side with respect to the center of the second flange portion30in the direction along the second axis Y. Details of the first metal terminal41to the fourth metal terminal44will be described later.

As illustrated inFIG.2, the coil component10includes a first wire51and a second wire52. Although not illustrated, the first wire51includes a copper wire and an insulating film. The insulating film covers the outer surface of the copper wire. The first wire51has a substantially circular shape in a section orthogonal to the direction in which the first wire51extends. An outer diameter L1of the first wire51is about 50 μm.

A first connection end of the first wire51is joined to the first metal terminal41by thermocompression bonding. The first wire51extends from the first metal terminal41toward the ridgeline of the winding core portion11on the first negative direction X2side and the second positive direction Y1side. When viewed in the third negative direction Z2, the first wire51is wound around the winding core portion11so as to travel clockwise as it goes toward the third negative direction Z2. A second connection end of the first wire51opposite to the first connection end extends toward the third metal terminal43from the ridgeline of the winding core portion11on the first positive direction X1side and the second negative direction Y2side. The second connection end of the first wire51is joined to the third metal terminal43by thermocompression bonding.

The thermocompression bonding is a method of sandwiching a wire between a metal terminal and a heated jig, and fixing the wire to the metal terminal while melting the wire. As a result of this fixing method, the insulating film is peeled off in the vicinity of the joining portion with the metal terminal in the wire, and the copper wire is exposed.

The second wire52has the same configuration as the first wire51. That is, the second wire52includes a copper wire and an insulating film. An outer diameter L1of the second wire52is about 50 μm.

A first connection end of the second wire52is joined to the second metal terminal42by thermocompression bonding. The second wire52extends from the second metal terminal42toward the ridgeline of the winding core portion11on the first positive direction X1side and the second positive direction Y1side. When viewed in the third negative direction Z2, the second wire52is wound around the winding core portion11so as to travel clockwise as it goes toward the third negative direction Z2. A second connection end of the second wire52opposite to the first connection end extends toward the fourth metal terminal44from the ridgeline of the winding core portion11on the first negative direction X2side and the second negative direction Y2side. The second connection end of the second wire52is joined the fourth metal terminal44by thermocompression bonding.

As illustrated inFIG.6, the first metal terminal41includes a bonding portion410, a coupling portion420, a mounting portion430, an extending portion440, and a joining portion450. The bonding portion410, the coupling portion420, the mounting portion430, the extending portion440, and the joining portion450are integrally molded. That is, there is no clear boundary between these members inside the first metal terminal41.

In the following description, among the directions along the central axis C, a direction from each metal terminal toward the winding core portion11may be referred to as an inward direction, and a direction opposite to the inward direction may be referred to as an outward direction. For example, the inward direction from the first metal terminal41toward the winding core portion11coincides with the third negative direction Z2. The outward direction with reference to the first metal terminal41coincides with the third positive direction Z1.

As illustrated inFIG.1, the bonding portion410has a substantially plate shape. As illustrated inFIG.7, the bonding portion410is fixed to the outer end surface20A of the first flange portion20with an adhesive60interposed therebetween. That is, the bonding portion410is joined to a surface facing the third positive direction Z1among the outer surfaces of the first flange portion20. As described above, the bonding portion410is a portion of the first metal terminal41facing the outer end surface20A of the first flange portion20from the third positive direction Z1side.

As illustrated inFIG.6, the bonding portion410has a facing surface411and a recess412. As illustrated inFIG.7, the facing surface411is a surface facing the outer end surface20A from the third positive direction Z1side except for the recess412. That is, the facing surface411of the first metal terminal41is a surface facing the third negative direction Z2.

As illustrated inFIG.6, the bonding portion410includes a wide portion410A and a narrow portion410B. The wide portion410A is a part including an end of the bonding portion410in the first negative direction X2. The wide portion410A has a substantially rectangular shape in which two adjacent corners on the first negative direction X2side are chamfered when viewed in the third positive direction Z1. The dimension of the wide portion410A in the direction along the second axis Y is substantially constant except for the chamfered portions. The wide portion410A includes a portion having the largest dimension in the direction along the second axis Yin the facing surface411and the recess412.

The narrow portion410B is adjacent to the wide portion410A on the first positive direction X1side. Specifically, the narrow portion410B extends in the first positive direction X1from an end of the wide portion410A in the second negative direction Y2. InFIG.6, a boundary between the narrow portion410B and the wide portion410A is virtually indicated by a broken line. The narrow portion410B has a smaller dimension in the direction along the second axis Y than the wide portion410A. The dimension of the narrow portion410B in the direction along the second axis Y is ½ or less of the dimension of the wide portion410A in the direction along the second axis Y. The dimension of the narrow portion410B in the direction along the second axis Y is substantially constant except for a coupling portion with the wide portion410A.

As illustrated inFIG.7, the recess412is recessed with respect to the facing surface411. The adhesive60is accommodated in the recess412. However, the adhesive60is not accommodated in a part of the recess412including an end in the first positive direction X1.

As illustrated inFIG.6, the recess412is located across the wide portion410A and the narrow portion410B. The end431of the recess412on the first negative direction X2side is located on the first positive direction X1side with respect to the end of the bonding portion410in the first negative direction X2. That is, the recess412is not opened toward the end of the bonding portion410in the first negative direction X2. As illustrated inFIG.7, the end431of the recess412on the first negative direction X2side is located on the first negative direction X2side as viewed from the central axis C.

An end432of the recess412on the first positive direction X1side is located on the first negative direction X2side with respect to the end of the bonding portion410in the first positive direction X1. That is, the end432of the recess412on the first positive direction X1side is located on the first negative direction X2side as viewed from the upper end surface22A of the first flange portion20. As illustrated inFIG.7, the end432of the recess412on the first positive direction X1side is located on the first positive direction X1side as viewed from the end of the winding core portion11on the first positive direction X1side.

As illustrated inFIG.6, the recess412of the narrow portion410B extends over the entire narrow portion410B in the direction along the second axis Y. Further, the recess412of the wide portion410A extends over the entire wide portion410A in the direction along the second axis Y. That is, in the direction along the second axis Y, the maximum dimension of the recess412located in the wide portion410A is larger than the maximum dimension of the narrow portion410B.

The edge of the recess412on the first negative direction X2side is substantially parallel to the second axis Y. The edge of the recess412on the first positive direction X1side is substantially parallel to the second axis Y. The distance from the edge of the recess412on the first negative direction X2side to the boundary line between the wide portion410A and the narrow portion410B is larger than the distance from the boundary line between the wide portion410A and the narrow portion410B to the edge of the recess412on the first positive direction X1side. That is, the area of the portion of the recess412located in the wide portion410A is larger than the area of the portion of the recess412located in the narrow portion410B. In the present embodiment, the dimensional ratio between the wide portion410A and the narrow portion410B is about 5:2. The dimension of the wide portion410A in the direction along the second axis Y is smaller than the dimension of the drum core10C in the direction along the second axis Y. That is, the dimension of the wide portion410A is 2.5 mm or less.

The dimension of the recess412in the direction along the third axis Z, that is, the depth of the recess412is substantially constant except for the edge of the recess412. In the present embodiment, the depth of the recess412is approximately half the plate thickness of the bonding portion410. For example, the plate thickness of the bonding portion410is 0.2 mm, and the depth of the recess412is 0.1 mm. Therefore, reflecting the above-described difference in area, the volume V1of the portion of the recess412located in the wide portion410A is larger than the volume V2of the portion of the recess412located in the narrow portion410B.

As illustrated inFIG.7, a region where the facing surface411and the recess412are combined, that is, a region of the first metal terminal41facing the outer end surface20A of the first flange portion20is defined as a facing region P. As illustrated inFIG.6, when viewed in the direction along the central axis C, the area of the region of the recess412facing the outer end surface20A of the first flange portion20is ½ or more of the facing region P. That is, the area of the region of the recess412facing the outer end surface20A of the first flange portion20is equal to or larger than the area of the facing surface411. Further, as illustrated inFIG.7, the maximum dimension L3of the recess412in the direction along the first axis X is ½ or more of the maximum dimension L4of the facing region P in the direction along the first axis X. Note that “when viewed in the direction along the central axis C” is not limited to those that can be directly visually recognized, and includes a case where it is viewed while being transmitted as described above.

As illustrated inFIG.7, the coupling portion420is connected to an end of the bonding portion410in the first positive direction X1. InFIG.6, the boundary between the coupling portion420and the bonding portion410is virtually indicated by a broken line. The coupling portion420extends from the bonding portion410in the first positive direction X1. That is, the coupling portion420protrudes from the first flange portion20in the direction along the first axis X when viewed in the direction along the third axis Z. Specifically, the coupling portion420protrudes toward the first positive direction X1side with respect to the upper end surface22A of the first flange portion20. The coupling portion420is bent by about 90 degrees on the way. An end of the coupling portion420opposite to the bonding portion410faces the third negative direction Z2.

As illustrated inFIG.4, the mounting portion430is connected to an end of the coupling portion420opposite to the bonding portion410. The mounting portion430has a flat plate shape. The main surface of the mounting portion430is orthogonal to the first axis X. The mounting portion430is a portion of the first metal terminal41that is located closest to the first positive direction X1side. The mounting portion430is separated from the upper end surface22A of the first flange portion20on the first positive direction X1side. That is, there is a gap between the mounting portion430and the upper end surface22A. The mounting portion430is separated from any outer surface of the drum core10C including the upper end surface22A. The mounting portion430is a portion facing a substrate when the coil component10is mounted on the substrate.

As illustrated inFIG.5, the shortest distance W1from the mounting portion430to the upper end surface22A in the direction along the first axis X is larger than the minimum dimension W2of the mounting portion430in the direction along the first axis X. In the present embodiment, the dimension of the mounting portion430in the direction along the first axis X is the plate thickness of the first metal terminal41. The plate thickness is substantially constant. The plate thickness of the first metal terminal41is substantially constant at the bonding portion410excluding the recess412, the coupling portion420, the mounting portion430, and the extending portion440.

As illustrated inFIG.4, the extending portion440is connected to an end of the mounting portion430on the second positive direction Y1side. The extending portion440extends substantially obliquely from the mounting portion430toward the second positive direction Y1side and the first negative direction X2side. The dimension of the extending portion440in the direction along the third axis Z, that is, the width dimension of the extending portion440is substantially constant. As illustrated inFIG.5, when viewed in the direction along the third axis Z, the extending portion440extends so as to approach the side surface22B of the protruding portion22facing the second positive direction Y1side as it goes in the first negative direction X2. The surface of the extending portion440facing the second negative direction Y2is in line contact with the side surface22B of the protruding portion22. When the extending portion440does not have a surface parallel to the side surface22B, the extending portion440is in line contact with the side surface22B.

As illustrated inFIG.5, specifically, among the angles formed by the side surface22B and the upper surface21A when viewed in the third positive direction Z1, an angle on the second positive direction Y1side and the first positive direction X1side is defined as a first angle θ1. The extending portion440has a portion extending linearly. Among the angles formed by the imaginary line VL0passing through the center of the linearly extending portion and the upper surface21A, the angle on the second positive direction Y1side and the first positive direction X1side is defined as a second angle θ2. At this time, the second angle θ2is smaller than the first angle θ1.

As illustrated inFIG.4, the joining portion450is connected to an end of the extending portion440on the first negative direction X2side. The joining portion450has a substantially plate shape. The joining portion450has a substantially rectangular shape elongated in the third axis Z direction when viewed in the direction along the first axis X. As illustrated inFIG.3, the maximum dimension W4of the joining portion450in the direction along the third axis Z is larger than the maximum dimension W3of the extending portion440in the direction along the third axis Z, that is, the width dimension of the extending portion440.

As illustrated inFIG.4, the joining portion450faces the upper surface21A of the first flange portion20from the first positive direction X1side. A surface of the joining portion450facing the first negative direction X2is in contact with the upper surface21A. On the other hand, the surface of the joining portion450facing the first negative direction X2is not fixed to the upper surface21A. That is, the adhesive60and the like are not interposed between the surface of the joining portion450facing the first negative direction X2and the upper surface21A.

When viewed in the direction along the first axis X, the joining portion450does not protrude from the upper surface21A of the first flange portion20in the third negative direction Z2. That is, the end of the upper surface21A of the first flange portion20on the third negative direction Z2side is located on the third negative direction Z2side with respect to the end of the joining portion450on the third negative direction Z2side.

The joining portion450has a horizontal surface451and an inclined surface452. The horizontal surface451faces the first positive direction X1. The horizontal surface451is a surface located closest to the third positive direction Z1side among the outer surfaces of the joining portion450. When viewed in the direction along the first axis X, the horizontal surface451has a substantially rectangular shape.

The inclined surface452further has a first inclined surface452A and a second inclined surface452B. The first inclined surface452A is a flat surface facing the first positive direction X1side and the third negative direction Z2side. The first inclined surface452A is adjacent to the horizontal surface451on the third negative direction Z2side. The first inclined surface452A is located in the first negative direction X2toward the third negative direction Z2.

The second inclined surface452B is a flat surface facing the first positive direction X1side and the third negative direction Z2side. The second inclined surface452B is adjacent to the first inclined surface452A on the third negative direction Z2side. The second inclined surface452B is located in the first negative direction X2toward the third negative direction Z2. The second inclined surface452B reaches an end of the joining portion450on the third negative direction Z2side.

As illustrated inFIG.3, when viewed in the direction along the second axis Y, the virtual straight line VL1passing through the end E1of the first inclined surface452A on the third positive direction Z1side and parallel to the central axis C is drawn. An acute angle formed by the first inclined surface452A and the virtual straight line VL1is defined as an angle P1. When viewed in the direction along the second axis Y, the virtual straight line VL2passing through the end E2of the second inclined surface452B on the third negative direction Z2side and parallel to the central axis C is drawn. The acute angle formed by the second inclined surface452B and the virtual straight line VL2is defined as an angle P2. At this time, the angle P2is larger than the angle P1.

Both the first inclined surface452A and the second inclined surface452B are flat surfaces. Therefore, the tangent at the end E1of the first inclined surface452A on the third positive direction Z1side is a line extending on the first inclined surface452A. Similarly, the tangent at the end E2of the second inclined surface452B on the third negative direction Z2side is a line extending on the second inclined surface452B.

In addition, the distance L2in the direction along the first axis X from the end E1of the inclined surface452in the third positive direction Z1to the end E2of the inclined surface452in the third negative direction Z2is about 70 μm. That is, the distance L2in the direction along the first axis X from the end E1of the inclined surface452in the third positive direction Z1to the end E2of the inclined surface452in the third negative direction Z2is larger than the outer diameter L1of the first wire51.

As illustrated inFIG.1, the second metal terminal42has a shape inverted in the direction along the second axis Y with respect to the first metal terminal41. Similarly to the first metal terminal41, the second metal terminal42is joined to the outer end surface20A of the first flange portion20at the bonding portion410. The third metal terminal43has the same shape as the second metal terminal42. The third metal terminal43is joined to the outer end surface30A of the second flange portion30at the bonding portion410. The fourth metal terminal44has the same shape as the first metal terminal41. The fourth metal terminal44is joined to the outer end surface30A of the second flange portion30at the bonding portion410.

<Joining of First Wire and Joining Portion>

When the first wire51is joined to the joining portion450, the first connection end of the first wire51is disposed on the horizontal surface451, and a jig is pressed parallel to the horizontal surface451. The jig is a heater chip. The jig is in contact with the first wire51on the horizontal surface451and a part of the first wire51on the third positive direction Z1side on the first inclined surface452A. When the first wire51comes into contact with the jig, the insulating film in the first wire51melts. That is, in the entire first wire51on the horizontal surface451and a part of the first wire51on the first inclined surface452A, the insulating film is peeled off, and the copper wire is exposed. Further, at the time of thermocompression bonding, the first wire51on the horizontal surface451is crushed and flattened by the load of the jig. Similarly, a part of the first wire51on the third positive direction Z1side on the first inclined surface452A in contact with the jig is flat. At the time of the thermocompression bonding, a part of the first wire51on the first inclined surface452A and the first wire51on the second inclined surface452B that do not come into contact with the jig are in a state where the insulating film remains. In addition, since the first wire51on the second inclined surface452B does not come into contact with the jig, it is not flat.

OPERATION OF PRESENT EMBODIMENT

When the first metal terminal41is attached to the first flange portion20, first, the adhesive60is applied to the outer end surface20A. Then, the facing surface411is brought into contact with the outer end surface20A so that the adhesive60is accommodated in the recess412in the first metal terminal41. The recess412is disposed so that the first positive direction X1side is hollow without the adhesive60adhering thereto. In this manner, the first metal terminal41is attached to the first flange portion20.

Effects of Present Embodiment

The effects of the present embodiment will be described. Hereinafter, the effects of the first metal terminal41will be described as a representative, but the same effects are obtained in each metal terminal.

(1) According to the above embodiment, the area of the region of the recess412facing the outer end surface20A is equal to or larger than the area of the facing surface411. By providing the recess412over a wide range in this manner, if a large amount of adhesive60is applied, it is possible to prevent the adhesive60from protruding out of the range of the recess412. In addition, since the large amount of adhesive60can be accommodated in the recess412, improvement of the bonding strength of the first metal terminal41to the first flange portion20can be expected.

(2) In the above embodiment, the joining portion450is located on the second positive direction Y1side with respect to the end of the narrow portion410B on the second positive direction Y1side. In the above embodiment, the mounting portion430is located on the second negative direction Y2side with respect to the end of the recess412on the second positive direction Y1side. Therefore, when the first wire51is crimped to the joining portion450and when the mounting portion430is attached to the substrate, a force in the rotation direction about the central axis C of the winding core portion11may act on the first metal terminal41. According to the above embodiment, the maximum dimension of the recess412of the wide portion410A in the direction along the second axis Y is larger than the maximum dimension of the narrow portion410B in the direction along the second axis Y. That is, the recess412exists over a considerable length in the direction along the second axis Y. Therefore, when the force in the rotation direction acts on the first metal terminal41, it is possible to suppress the first metal terminal41from being inclined with respect to the second axis Y.

(3) According to the above embodiment, the volume V1of the portion of the recess412located in the wide portion410A is larger than the volume V2of the portion of the recess412located in the narrow portion410B. According to this configuration, a large amount of adhesive60can be accommodated in the portion of the recess412located in the wide portion410A. Therefore, when the force in the rotation direction about the central axis C acts as described above, the effect of preventing the first metal terminal41from being inclined with respect to the second axis Y can be more reliably exhibited.

(4) According to the above embodiment, the recess412extends over the entire wide portion410A in the direction along the second axis Y. According to this configuration, as compared with the configuration in which the recess412does not extend over the entire wide portion410A in the direction along the second axis Y, a larger amount of adhesive60can be accommodated in the wide portion410A. Therefore, when the force in the rotation direction about the central axis C acts as described above, the effect of preventing the first metal terminal41from being inclined with respect to the second axis Y can be more reliably exhibited.

(5) In the above embodiment, the mounting portion430is located on the first positive direction X1side with respect to the recess412. Therefore, when the mounting portion430is attached to the substrate, a force in a rotation direction about an axis parallel to the second axis Y may act on the first metal terminal41. In the above embodiment, the maximum dimension L3of the412recesses in the direction along the first axis X is ½ or more of the maximum dimension L4of the facing region P in the direction along the first axis X. According to this configuration, the recess412is provided over a considerable range in the direction along the first axis X. Therefore, when the force in the rotation direction acts on the end of the first metal terminal41, the first metal terminal41is hardly peeled off from the first flange portion20.

(6) In the above embodiment, the end432of the recess412on the first positive direction X1side is located on the first negative direction X2side as viewed from the end of the first flange portion20on the first positive direction X1side. Therefore, the adhesive60accommodated in the recess412is accommodated between the first flange portion20and the recess412. That is, it is difficult for the adhesive60to reach above the upper end surface22A of the first flange portion20. When the adhesive60does not exist on the upper end surface22A, the mounting portion430of the first metal terminal41is not unintentionally joined to the upper end surface22A.

The end432of the recess412on the first positive direction X1side is located on the first positive direction X1side as viewed from the end of the winding core portion11on the first positive direction X1side. Therefore, when the force in the rotation direction about the second axis Y acts on the end of the first metal terminal41, the first metal terminal41is hardly peeled off from the first flange portion20.

(7) In the above embodiment, the end431of the recess412on the first negative direction X2side is located in the first negative direction X2as viewed from the central axis C. That is, according to this configuration, the recess412is provided over a considerable range in the direction along the first axis X. Therefore, when the force in the rotation direction about the second axis Y acts on the end of the first metal terminal41, the first metal terminal41is hardly peeled off from the first flange portion20.

(8) In the above embodiment, the adhesive60is not accommodated in a part of the recess412including the end432in the first positive direction X1. According to this configuration, since there is a space in which the adhesive60is not accommodated in the recess412, the adhesive60hardly leaks from the recess412. In particular, the adhesive60hardly leaks in the first positive direction X1with respect to the recess412. Therefore, the adhesive60hardly reaches above the upper end surface22A of the first flange portion20.

Modification

The present embodiment can be modified as follows. The present embodiment and the following modifications can be implemented in combination with each other within a range not technically contradictory. A modification common to the first metal terminal41to the fourth metal terminal44will be described only for the first metal terminal41as a representative.

In the above embodiment, the configuration of the coil component10is not limited. For example, the top plate12can be omitted from the coil component10. The shape of the first flange portion20is not limited to the shape of the above embodiment. For example, the protruding portion22can be omitted from the first flange portion20.

In the above embodiment, the second wire52may be omitted from the coil component10. For example, when the coil component10includes only the first wire51, one metal terminal may be attached to each flange portion.

In the above embodiment, the winding core portion11may not have a quadrangular prism shape. For example, the sectional shape of the winding core portion11may be a circular shape, an elliptical shape, or a polygonal shape other than a quadrangular shape.

In the above embodiment, the shape of the first metal terminal41is not limited to the example of the above embodiment. The first metal terminal41may have the facing surface411and the recess412.

In the above embodiment, the joining portion450may be separated from the upper surface21A. In addition, the adhesive60may be accommodated between the joining portion450and the upper surface21A.

In the above embodiment, there may be no clear boundary between the first inclined surface452A and the second inclined surface452B in the joining portion450. That is, the inclined surface452may be configured such that the inclination angle changes gently.

In the above embodiment, the configuration of the joining portion450is not limited to the example of the above embodiment. For example, the joining portion450may further include a second horizontal surface in addition to the horizontal surface451.

In the above embodiment, the horizontal surface451can be omitted from the joining portion450. That is, the joining portion450may include only the inclined surface452. In this case, the first wire51is preferably joined to the inclined surface452at a portion of the inclined surface452closer to the outward direction. The joining portion450may further has an inclined surface in addition to the first inclined surface452A and the second inclined surface452B.

In the above embodiment, the angle P2of the inclined surface452of the joining portion450may be smaller than the angle P1.

In the above embodiment, the inclined surface452of the joining portion450may include only one inclined surface. In addition, the inclined surface may be a curved surface instead of a flat surface. In the above embodiment, the joining portion450may not have the inclined surface452and may include only the horizontal surface451.

In the above embodiment, the end of the upper surface21A on the third negative direction Z2side may be located on the third positive direction Z1side with respect to the end of the joining portion450on the third negative direction Z2side. That is, the joining portion450may protrude from the first flange portion20.

In the above embodiment, the distance L2in the direction along the first axis X from the end E1of the inclined surface452in the third positive direction Z1to the end E2of the inclined surface452in the third negative direction Z2may be smaller than or equal to the outer diameter L1of the first wire51.

In the above embodiment, the maximum dimension W3of the extending portion440in the direction along the third axis Z may be larger than or the same as the maximum dimension W4of the joining portion450in the direction along the third axis Z.

In the above embodiment, the position of the recess412is not limited to the example of the above embodiment. That is, the end432of the recess412on the first positive direction X1side may be located on the first positive direction X1side with respect to the end of the bonding portion410in the first positive direction X1. The end431of the recess412on the first negative direction X2side may be located on the first positive direction X1side as viewed from the central axis C.

In the above embodiment, the positional relationship between the fixing portion of the first wire51in the first metal terminal41and the recess412is not limited to the example of the above embodiment. For example, in the example illustrated inFIG.8, the end of the wide portion410A of the first metal terminal41in the second positive direction Y1is at the same position as the end of the joining portion450in the second positive direction Y1in the direction along the second axis Y. Therefore, the first connection end of the first wire51joined to the joining portion450is located within the range where the recess412exists in the direction along the second axis Y. According to this configuration, when the force in the rotation direction about the central axis C acts due to the load when crimping the first wire51to the joining portion450, it is possible to suppress the first metal terminal41from being inclined with respect to the second axis Y.

In the above embodiment, the dimension of the bonding portion410in the direction along the second axis Y may be constant. That is, the bonding portion410may not be roughly divided into the wide portion410A and the narrow portion410B.

In the above embodiment, the recess412may not extend over the entire wide portion410A in the direction along the second axis Y. Similarly, the recess412may not extend over the entire narrow portion410B in the direction along the second axis Y. The volume V1of the portion of the recess412located in the wide portion410A may be smaller than or equal to the volume V2of the portion of the recess412located in the narrow portion410B.

In the above embodiment, the maximum dimension L3of the recess412in the direction along the first axis X may be smaller than ½ of the maximum dimension L4of the facing region P.

In the above embodiment, the adhesive60may be accommodated up to the end432of the recess412in the first positive direction X1. Further, the adhesive60may reach the facing surface411and the coupling portion420.

In the above embodiment, the mounting portion430may be in contact with the upper end surface22A of the protruding portion22. That is, the mounting portion430may be in contact with the outer surface of the drum core10C. In addition, the adhesive60may be applied between the mounting portion430and the protruding portion22.

In the above embodiment, the shortest distance W1from the mounting portion430to the upper end surface22A may be smaller than or equal to the minimum dimension W2of the mounting portion430in the direction along the first axis X.

In the above embodiment, the extending portion440may not be in contact with the side surface22B. The extending portion440may extend away from the side surface22B as it goes toward the first negative direction X2.

Technical ideas that can be derived from the above embodiments and modifications will be described below.

[1] A coil component including: a drum core including a columnar winding core portion, a first flange portion connected to a first end of the winding core portion in a direction along a central axis of the winding core portion, and a second flange portion connected to a second end of the winding core portion opposite to the first end; a first metal terminal attached to the first flange portion; and a wire wound around the winding core portion and having a first connection end joined to the first metal terminal. When a direction from the first metal terminal toward the winding core portion in a direction along the central axis is defined as an inward direction, and a direction opposite to the inward direction is defined as an outward direction, the first flange portion has an outer end surface facing a side of the outward direction, the first metal terminal includes a bonding portion fixed to the outer end surface, and the bonding portion has a facing surface facing the outer end surface from the outward direction side, and a recess recessed with respect to the facing surface and accommodating an adhesive. When viewed in a direction along the central axis, an area of a region of the recess facing the outer end surface is equal to or larger than an area of the facing surface.

[2] The coil component according to [1], in which when a specific axis orthogonal to the central axis is defined as a first axis, and an axis orthogonal to both the central axis and the first axis is defined as a second axis, the first metal terminal includes a wide portion and a narrow portion adjacent to the wide portion in a direction along the first axis and having a smaller dimension in a direction along the second axis than the wide portion, in which the recess is located in the wide portion and the narrow portion, and in which a maximum dimension of the recess located in the wide portion is larger than a maximum dimension of the narrow portion in the direction along the second axis.

[3] The coil component according to [2], in which a volume of a portion of the recess located in the wide portion is larger than a volume of a portion of the recess located in the narrow portion.

[4] The coil component according to [2] or [3], in which the recess extends over the entire wide portion in the direction along the second axis.

[5] The coil component according to any one of [1] to [4], in which when a specific axis orthogonal to the central axis is defined as a first axis, the first metal terminal includes a coupling portion that is connected to the bonding portion and protrudes from the first flange portion in a direction along the first axis, and in which when a region obtained by combining the facing surface and the recess is defined as a facing region, a maximum dimension of the recess in the direction along the first axis is ½ or more of a maximum dimension of the facing region in the direction along the first axis.

[6] The coil component according to any one of [1] to [5], in which when a specific axis orthogonal to the central axis is defined as a first axis, one of directions along the first axis is defined as a first positive direction, and a direction opposite to the first positive direction is defined as a first negative direction, the first metal terminal includes a coupling portion that is connected to the bonding portion and protrudes from the first flange portion in a direction along the first axis, an end of the recess on a side of the first positive direction is located on a side of the first negative direction as viewed from an end of the first flange portion on the side of the first positive direction, and is located on the side of the first positive direction as viewed from an end of the winding core portion on the side of the first positive direction, and an end of the recess on the side of the first negative direction is located in the first negative direction as viewed from the central axis.

[7] The coil component according to any one of [1] to [6], in which when a specific axis orthogonal to the central axis is defined as a first axis and a specific axis orthogonal to the central axis is defined as a second axis, the first metal terminal includes a coupling portion that is connected to the bonding portion and protrudes from the first flange portion in a direction along the first axis, and a first connection end of the wire is located within a range where the recess exists in a direction along the second axis.

[8] The coil component according to any one of [1] to [7], in which when a specific axis orthogonal to the central axis is defined as a first axis, and one of directions along the first axis is defined as a first positive direction, the first metal terminal includes a coupling portion that is connected to the bonding portion and protrudes from the first flange portion in a direction along the first axis, and the adhesive is not accommodated in a part of the recess including an end in the first positive direction.