Coil component

Abstract

To provide a coil component which is able to increase bonding strength to a mounting substrate and also to increase connection strength between a wire and a terminal electrode.SOLUTION: A flange 5 of a core 2 includes: a mounting surface 7 facing a mounting substrate side during mounting; an inner end surface 9 facing a winding core 3 side; and an outer end surface 10 on an opposite side from the inner end surface 9. A terminal electrode 21 includes a base layer 31 formed by, for example, the baking of silver, and a tin layer 32 covering the base layer. The base layer 31 is provided to extend to the mounting surface 7, and to part of each of the inner end surface 9 and the outer end surface 10 from the mounting surface 7. In a cross section of a connection part between a wire 23 and the terminal electrode 21, a position H1 of a tip of a portion, of the base layer 31, extending along the inner end surface 9 in a height direction is higher than a position H2 of a tip of a portion, of the base layer, extending along the outer end surface 10 in the height direction, and a position H3 of a tip of a portion, of the tin layer 32, extending along the inner end surface 9 in the height direction is lower than a position H4 of a tip of a portion, of the tin layer, extending along the outer end surface 10 in the height direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a wire-wound coil component, and more particularly to the structure of a terminal electrode provided on a core. [Background technology]

[0002] For example, as described in JP 2005-347588 A (Patent Document 1), a wound coil component generally comprises a core having a winding core portion and a first flange portion and a second flange portion respectively provided at a first end portion and a second end portion respectively opposite to each other in the axial direction of the core, a first terminal electrode and a second terminal electrode respectively provided at the first flange portion and the second flange portion, and a wire wound around the winding core portion while being connected between the first terminal electrode and the second terminal electrode.

[0003] Each of the first flange portion and the second flange portion has a mounting surface that faces the mounting board when mounted, an inner end face that faces the winding core portion, an outer end face opposite the inner end face, and a first side surface and a second side surface that connect the inner end face and the outer end face.

[0004] As can be seen, for example, from FIG. 1 of Patent Document 1, each of the first terminal electrode and the second terminal electrode is formed so as to cover the mounting surfaces of the first flange portion and the second flange portion, and is formed so as to extend from the mounting surfaces to portions of the inner end face, the outer end face, the first side face, and the second side face adjacent to the mounting surfaces.

[0005] As described in, for example, paragraphs 0016 and 0023 of Patent Document 1, the terminal electrode has a base layer electrode and an upper layer electrode. The base layer electrode is formed by baking a conductive material such as Ag or Cu, and the upper layer electrode is formed by plating a conductive material such as Ni or Sn. In the upper layer electrode, a Sn layer is located at the top to increase the bonding strength between the wire and the terminal electrode. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2005-347588 A Summary of the Invention [Problem to be solved by the invention]

[0007] In recent years, the automotive market has been demanding high reliability for coil components, etc. To achieve high reliability, for example, the coil components need to have high adhesion strength to a mounting board, high connection strength between the wires and terminal electrodes in the coil components, etc.

[0008] In order to increase the strength of the coil component's attachment to the mounting board, the solder fillet must be formed with a sufficient height from the mounting board when the coil is mounted. In forming the solder fillet, the portion of the terminal electrode provided on the core that is formed so as to extend to a part of the flange, particularly the outer end face, plays an important role. In other words, the Sn layer that exhibits good solder wettability must be formed with a sufficient height in this portion.

[0009] Furthermore, in order to increase the connection strength between the wire and the terminal electrode in the coil component, a sufficient amount of Sn must be able to be supplied from the terminal electrode to the wire.

[0010] However, Patent Document 1 does not clearly describe a technique that makes it possible to fully satisfy the above-mentioned demands.

[0011] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a coil component structure that can increase the strength of attachment to a mounting board and the strength of connection between wires and terminal electrodes. [Means for solving the problem]

[0012] The present invention is directed to a coil component comprising: a core having a winding core portion extending in an axial direction and a first flange portion and a second flange portion respectively provided at a first end portion and a second end portion opposite to each other in the axial direction of the winding core portion; a first terminal electrode and a second terminal electrode respectively provided at the first flange portion and the second flange portion; and at least one wire wound around the winding core portion while being connected between the first terminal electrode and the second terminal electrode.

[0013] Each of the first flange and the second flange has a mounting surface that faces the mounting board when mounted, an inner end surface that faces the winding core portion, and an outer end surface opposite the inner end surface.

[0014] Each of the first terminal electrode and the second terminal electrode includes a base layer and a tin layer containing tin, the base layer being provided to extend to the mounting surface and from the mounting surface to each of a portion of the inner end surface and the outer end surface, and the tin layer being provided to cover the base layer and to form at least the outermost layer of each of the first terminal electrode and the second terminal electrode.

[0015] In order to solve the above-mentioned technical problems in a coil component having such a configuration, the present invention is characterized by having the following configuration.

[0016] That is, when a direction away from the mounting surface along the extending direction of the inner end surface and the outer end surface is taken as a height direction, and a cross section of a connection portion between a wire and a terminal electrode of at least one of the first terminal electrode and the second terminal electrode is viewed, the cross section being perpendicular to all of the mounting surface, the inner end surface, and the outer end surface, (1) The height position of the tip of the portion of the base layer extending along the inner end surface is higher than the height position of the tip of the portion of the base layer extending along the outer end surface, (2) The tin layer has a tip end of a portion extending along the inner end surface that is lower in the height direction than a tip end of a portion extending along the outer end surface. It is characterized by the following. Effect of the Invention

[0017] According to this invention, when viewed in cross section at the connection portion between the wire and the terminal electrode, the base layer is lower on the outer end face side than on the inner end face side, and the tin layer is higher on the outer end face side than on the inner end face side, so that more tin can be present on the outer end face side, which allows good solder wettability to be achieved on the outer end face side during mounting, and allows a solder fillet of sufficient height to be formed, which contributes to improving the fixing strength to the mounting board.

[0018] In addition, since the difference in height between the tin layer, which is formed higher than the base layer on the outer end face side, and the base layer can be increased, the contact area between the outer end face and the tin layer can be increased, and therefore the tin layer can advantageously mitigate the stress applied from the tip due to thermal shock when the coil component is mounted.

[0019] In addition, since the base layer is formed relatively high on the inner end face side, the tin layer covering the base layer is also formed to a sufficient height accordingly, so that the bonding area between the wire and the tin layer can be made large on the inner end face side, and the connection strength between the wire and the terminal electrode can be maintained high. [Brief description of the drawings]

[0020] [Figure 1] 1 is a front view showing an appearance of a coil device 1 according to a preferred embodiment of the present invention. [Diagram 2] 2 is a bottom view showing the coil component 1 shown in FIG. 1 from the mounting surfaces 7, 13 side. [Diagram 3] 3 is an enlarged view of a portion of the cross section of the coil device 1 shown in FIG. 2 taken along line III-III. [Figure 4] 4 is an enlarged view of a portion of the cross section of the coil device 1 shown in FIG. 2 taken along line IV-IV. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] A coil device 1 according to an embodiment of the present invention will be described with reference to FIGS.

[0022] 1 and 2, the coil device 1 includes a core 2. The core 2 is typically made of ferrite, but may also be made of other materials, such as ferrite powder, alumina powder, or resin containing magnetic metal powder. The core 2 has a winding core portion 3 extending in the axial direction A, and a first flange portion 5 and a second flange portion 6 provided at a first end portion and a second end portion, respectively, of the winding core portion 3 that are opposite to each other in the axial direction A.

[0023] The cross section of the winding core 3 perpendicular to the axial direction A is rectangular. The ridges of the rectangular cross section of the winding core 3 may be chamfered, or the cross section of the winding core 5 may be a polygon such as a hexagon, a circle, an ellipse, or an appropriate combination of these.

[0024] The first flange portion 5 and the second flange portion 6 are in the shape of a quadrangular prism. The first flange portion 5 and the second flange portion 6 have shapes symmetrical to each other.

[0025] The first flange portion 5 has a mounting surface 7 that faces the mounting board during mounting, a top surface 8 opposite the mounting surface 7, an inner end surface 9 that connects the mounting surface 7 and the top surface 8 and faces the winding core portion 3, an outer end surface 10 opposite the inner end surface 9, and a first side surface 11 and a second side surface 12 that connect the mounting surface 7 and the top surface 8 and the inner end surface 9 and the outer end surface 10 and face each other.

[0026] Similarly, the second flange portion 6 has a mounting surface 13 that faces the mounting board during mounting, a top surface 14 opposite the mounting surface 13, an inner end surface 15 that connects the mounting surface 13 and the top surface 14 and faces the winding core portion 3, an outer end surface 16 opposite the inner end surface 15, and a first side surface 17 and a second side surface 18 that connect between the mounting surface 13 and the top surface 14 and between the inner end surface 15 and the outer end surface 16 and face each other.

[0027] The ridges of the first flange 9 and the second flange 10 may be chamfered. Furthermore, the first flange 5 and the second flange 6 may have a shape other than a rectangular prism, so long as they have mounting surfaces 7 and 13, inner end faces 9 and 15, and outer end faces 10 and 16, respectively.

[0028] The coil component 1 may include a top plate 19. The top plate 19 is placed between the top surface 8 of the first flange 5 and the top surface 14 of the second flange 6, and is fixed to the core 2 by a thermosetting resin such as an epoxy adhesive (not shown). It is desirable that the dimensions of the top plate 19 in the axial direction A of the core 2 and in the direction perpendicular to the paper surface of FIG. 1 are equal to or greater than the dimensions of the core 2. The top plate 19 is made of ferrite, or a resin containing ferrite powder, alumina powder, or metal magnetic powder. Instead of the top plate 19, the top surface of the core 2 may be coated with a resin such as an ultraviolet-curing resin.

[0029] The coil component 1 includes a first terminal electrode 21 and a second terminal electrode 22 provided on at least the mounting surfaces 7 and 13 of the first flange portion 5 and the second flange portion, respectively. The areas where the first terminal electrode 21 and the second terminal electrode 22 are formed are distinguished from the other areas by being darkened in Fig. 1 and Fig. 2. That is, the terminal electrodes 21 and 22 are formed on the mounting surfaces 7 and 13, and are formed to extend to parts of the inner end faces 9 and 15, the outer end faces 10 and 16, the first side faces 11 and 17, and the second side faces 12 and 18 adjacent to the mounting surfaces 7 and 13. The details of the terminal electrodes 21 and 23 will be described later.

[0030] The coil component 1 further includes at least one wire 23 wound around the winding core 3 while being connected between the first terminal electrode 21 and the second terminal electrode 22. The wire 23 includes a central wire made of a highly conductive metal such as copper, silver, or gold, and the central wire is coated with a resin such as polyurethane or polyamideimide. There is no particular limit to the diameter of the central wire of the wire 23, but it is set to, for example, 60 μm or more and 180 μm or less. The number of turns of the wire 23 around the winding core 3 can be changed as desired depending on the desired characteristics.

[0031] Wire 23 is connected to terminal electrodes 21 and 22 by, for example, thermocompression. Mounting surfaces 7 and 13 may be provided with grooves 25 and 26 for receiving ends of wire 23. Grooves 25 and 26 extend in a direction connecting inner end faces 9 and 15 and outer end faces 10 and 16. The presence of grooves 25 and 26 allows wire 23 to be accommodated within grooves 25 and 26, thereby stabilizing the mounting state of coil component 1.

[0032] 4 for groove 25, each of bottom surfaces 29 and 30 of grooves 25 and 26 has a gradient that becomes deeper from the outer end face 10 side toward the inner end face 9 side. Each end of wire 23 is connected to first terminal electrode 21 and second terminal electrode 22 at bottom surfaces 29 and 30 of grooves 25 and 30, respectively.

[0033] As described above, by providing a gradient to bottom surfaces 29 and 30, damage to wire 23 during crimping can be reduced. This reduces the risk of wire 23 breaking near the crimped portion. If there is no gradient, wire 23 will rapidly become thinner at the end, increasing the risk of wire 23 breaking, but this can be avoided.

[0034] When each end of wire 23 is thermocompression bonded to terminal electrodes 21 and 22, respectively, wire 23 forms a bulge at bottom surfaces 29 and 30 of grooves 25 and 26, the bulge having a height of, for example, 15 μm and a width of 200 μm.

[0035] As shown in Figures 3 and 4, one terminal electrode 21 includes an underlayer 31 and a tin layer 32 containing tin. Since the first terminal electrode 21 and the second terminal electrode 22 have substantially the same cross-sectional structure, the first terminal electrode 21 shown in Figures 3 and 4 will be described in detail, and a detailed description of the second terminal electrode 22 will be omitted.

[0036] The base layer 31 is provided so as to extend onto the mounting surface 7 of the flange portion 5 and from the mounting surface 7 to each of parts of the inner end surface 9 and the outer end surface 10. Although not shown in Figures 3 and 4, in this embodiment, the base layer 31 is further provided so as to extend from the mounting surface 7 to each of parts of the first side surface 11 and the second side surface 12. The tin layer 32 is provided so as to cover the base layer 31 and to form at least the outermost layer of each of the terminal electrodes 21.

[0037] The underlayer 31 is, for example, a baked layer formed by applying and baking a conductive paste containing silver as a conductive component. The tin layer 32 is, for example, a plated layer formed by plating such as barrel plating.

[0038] Fig. 4 shows a cross section of the connection portion between wire 23 and first terminal electrode 21. Meanwhile, Fig. 3 shows a cross section of first terminal electrode 21 at a portion other than the connection portion. In the explanation with reference to Figs. 3 and 4, the direction away from mounting surface 7 along the extension direction of inner end face 9 and outer end face 10 is defined as the height direction.

[0039] First, as shown in FIG. 4, at the connection portion between the wire 23 and the first terminal electrode 21, (1) The height position H1 of the tip of the portion of the base layer 31 extending along the inner end surface 9 is higher than the height position H2 of the tip of the portion of the base layer 31 extending along the outer end surface 10. (2) The position H3 in the height direction of the tip of the portion of the tin layer 32 extending along the inner end surface 9 is lower than the position H4 in the height direction of the tip of the portion of the tin layer 32 extending along the outer end surface 10.

[0040] The relationship between the above-mentioned four height positions H1 to H4 is expressed as H1>H2, H4>H3, but the relationship between H1 and H3 is always H3≧H1. This is because, on the inner end surface 9 side, the tin layer 32 is formed so as to cover the base layer 31, and therefore the height position H3 of the tip of the tin layer 32 is never lower than the height position H1 of the tip of the base layer 31. From the above, the relationship between the four height positions H1 to H4 is expressed as H4>H3≧H1>H2.

[0041] Such a configuration provides the following effects.

[0042] A large amount of tin can be present on the outer end surface 10 side. Therefore, good solder wettability can be achieved on the outer end surface 10 side during mounting, and a solder fillet of sufficient height can be formed that contributes to improving the fixing strength to the mounting board.

[0043] In addition, since the difference in height between the tin layer 32, which is formed higher than the base layer 31 on the outer end face 10 side, and the base layer 31 can be increased, the contact area between the outer end face 10 and the tin layer 32 can be increased. The adhesion of the tin layer 32 to the core 2 is weaker than the adhesion of the base layer 31 to the core 2. Therefore, the tin layer 10 can advantageously relieve the stress applied from the tip of the terminal electrode 21.

[0044] In addition, since the base layer 31 is formed relatively high on the inner end face 9 side, the tin layer 32 covering the base layer 31 is also formed with a sufficient height accordingly. Therefore, the bonding area between the wire 23 and the tin layer 32 on the inner end face 9 side can be made large, and the connection strength between the wire 23 and the terminal electrode 21 can be maintained high.

[0045] In this embodiment, the above-mentioned height relationship is maintained at locations other than the connection portion between the wire 23 and the first terminal electrode 21. That is, as shown in FIG. (1) The height position H1 of the tip of the portion of the base layer 31 extending along the inner end surface 9 is higher than the height position H2 of the tip of the portion of the base layer 31 extending along the outer end surface 10. (2) The position H3 in the height direction of the tip of the portion of the tin layer 32 extending along the inner end surface 9 is lower than the position H4 in the height direction of the tip of the portion of the tin layer 32 extending along the outer end surface 10.

[0046] As can be seen from the states shown in Figures 3 and 4 above, in this embodiment, the tip of the portion of the base layer 31 extending along the inner end surface 9 is higher at all height positions H1 than the tip of the portion of the base layer 31 extending along the outer end surface 10, and the tip of the portion of the base layer 31 extending along the inner end surface 9 is lower at all height positions H3 than the tip of the portion of the base layer 32 extending along the outer end surface 10.

[0047] According to such a configuration, the above-mentioned effects are achieved over a wider range of the inner end surface 9 and the outer end surface 10. Therefore, more reliable effects can be expected.

[0048] Although not specifically shown, an intermediate layer containing a conductive component different from the conductive components contained in both the underlayer 31 and the tin layer 32 may be further provided between the underlayer 31 and the tin layer 32. This intermediate layer may be composed of a single layer or multiple layers containing different conductive components.

[0049] When the intermediate layer is included as described above, in a preferred embodiment, a conductive paste containing silver is applied and baked to form the underlayer 31, and then copper, nickel, and tin are plated in this order to form the intermediate layer and the tin layer 32. Here, for example, the silver layer has a thickness of 5 μm to 30 μm, the copper layer has a thickness of 1 μm to 5 μm, the nickel layer has a thickness of 1 μm to 5 μm, and the tin layer has a thickness of 5 μm to 20 μm. The intermediate layer may be a single layer, for example, a nickel layer.

[0050] Although detailed description of the configuration on the second terminal electrode 22 side has been omitted, the second terminal electrode 22 side also has a similar configuration to the illustrated first terminal electrode 21 side. However, the illustrated configuration on the first terminal electrode 21 side may be adopted only on the first terminal electrode 21 side.

[0051] The coil device 1 is manufactured, for example, as follows.

[0052] To obtain the drum-shaped core 2, ferrite powder is press-molded in a mold, the resulting molded body is sintered, and after sintering, burrs are removed by barrel polishing. At this time, the ridges of the core 2 are chamfered to give them a small radius.

[0053] Next, terminal electrodes 21 and 22 are formed on the flanges 5 and 6 of the obtained core 2.

[0054] More specifically, the first terminal electrode 21 is described below. First, the base layer 31 of the first terminal electrode 21 is formed by applying and baking, for example, a conductive paste containing silver as a conductive component. When applying the conductive paste to become the base layer 31, for example, an applicator for applying the conductive paste is operated so that the applied area of ​​the conductive paste is in the state shown in Figures 3 and 4, that is, so that the position H1 in the height direction of the tip of the portion extending along the inner end face 9 is higher than the position H2 in the height direction of the tip of the portion extending along the outer end face 10.

[0055] The second terminal electrode 22 is formed in the same manner as the first terminal electrode 21.

[0056] Next, for example, barrel plating is applied to form a tin plating film that becomes the tin layer 32. In this barrel plating, the frequency of collision of media is higher on the outer end face 10 side than on the inner end face 9 side, so plating deposition proceeds more on the outer end face 10 side. Here, it is not necessary to perform barrel plating for a long period of time to deposit more tin on the outer end face 10 side. In this way, the height position H4 of the tip of the portion of the tin layer 32 that extends along the outer end face 10 is higher than the height position H3 of the tip of the portion that extends along the inner end face 9.

[0057] Thereafter, a nozzle is used to wind the wire 23 around the winding core portion 3 of the core 2, and then a heater tip is used to thermocompress the ends of the wire 23 to the terminal electrodes 21 and 22. In the thermocompression bonding, for example, a temperature of 500°C and a bonding time of 1 second are applied. After the bonding, the temperature of the heater tip is lowered, and when the temperature reaches 300°C or less, the heater tip is lifted up. Next, the excess of the wire 23 connected to the terminal electrodes 21 and 22 is cut off by a cutting blade.

[0058] When the top plate 19 is provided, the top plate 19 is then fixed to the core 2 via an adhesive. When a resin coating is used instead of the top plate 19, the resin is applied to the core 2 and then cured.

[0059] The obtained coil component 1 has, for example, a dimension of 3.2 mm in the axial direction A, a dimension of 2.5 mm in the width direction perpendicular to the plane of FIG. 1, and a dimension of 2.5 mm in the height direction perpendicular to the plane of FIG.

[0060] While the present invention has been described with reference to the illustrated embodiment, various other modifications are possible within the scope of the present invention.

[0061] For example, the coil components to which the present invention is directed may be those constituting a single coil as in the illustrated embodiment, or those constituting a common mode choke coil, or those constituting a transformer, a balun, etc. Therefore, the number of wires may also be changed according to the function of the coil component, and the number of terminal electrodes and grooves provided in each flange may also be changed accordingly.

[0062] Furthermore, the shapes of the winding core and the top plate of the coil component are not limited to those shown in the drawings, and can be changed as desired according to the desired design.

[0063] Furthermore, in constructing the coil component according to the present invention, partial substitution or combination of configurations is possible between the different embodiments described in this specification.

[0064] The embodiments of the present invention include the following.

[0065] <1> a core having a winding core portion extending in an axial direction and a first flange portion and a second flange portion provided at a first end portion and a second end portion, respectively, opposite to each other in the axial direction of the winding core portion; a first terminal electrode and a second terminal electrode provided on the first flange portion and the second flange portion, respectively; at least one wire wound around the winding core while being connected between the first terminal electrode and the second terminal electrode; Equipped with each of the first flange portion and the second flange portion has a mounting surface that faces a mounting board during mounting, an inner end surface that faces the winding core portion, and an outer end surface opposite the inner end surface; each of the first terminal electrode and the second terminal electrode includes an underlayer and a tin layer containing tin; the base layer is provided so as to extend to the mounting surface and to a portion of each of the inner end surface and the outer end surface, the tin layer is provided so as to cover the base layer and to form at least an outermost layer of each of the first terminal electrode and the second terminal electrode, a direction away from the mounting surface along a direction in which the inner end surface and the outer end surface extend is defined as a height direction, With respect to at least one of the first terminal electrode and the second terminal electrode, when a cross section of a connection portion between the wire and the terminal electrode is viewed perpendicular to the mounting surface, the inner end surface, and the outer end surface, (1) the position of a tip of a portion of the base layer extending along the inner end surface in the height direction is higher than the position of a tip of a portion of the base layer extending along the outer end surface in the height direction; (2) The tin layer has a tip end of a portion extending along the inner end surface that is lower in the height direction than a tip end of a portion extending along the outer end surface. Coil parts.

[0066] <2> At least one of the first flange portion and the second flange portion on which the at least one terminal electrode is provided has a groove provided on the mounting surface, the groove extends in a direction connecting the inner end surface and the outer end surface and defines a bottom surface having a gradient that becomes deeper from the outer end surface side toward the inner end surface side, and the wire is connected to the terminal electrode at the bottom surface of the groove. <1> The coil component according to claim 1.

[0067] <3> In the at least one first terminal electrode, all of the height positions of the tip of the base layer that extends along the inner end surface are higher than all of the height positions of the tip of the part that extends along the outer end surface, and all of the height positions of the tip of the tin layer that extends along the inner end surface are lower than all of the height positions of the tip of the part that extends along the outer end surface. <1> or <2> The coil component according to claim 1.

[0068] <4> The underlayer is a baked layer of a conductive paste containing silver as a conductive component. <1> Or <3> 2. The coil component according to claim 1 .

[0069] <5> The tin layer is a plating layer. <1> Or <4> 2. The coil component according to claim 1 .

[0070] <6> the at least one terminal electrode is both the first terminal electrode and the second terminal electrode; <1> Or <5> 2. The coil component according to claim 1 . [Explanation of symbols]

[0071] 1 Coil parts 2 cores 3. Winding core 5,6 Flange 7,13 Mounting surface 9,15 Inner end face 10,16 Outer end face 21,22 terminal electrode 23 Wire 25,26 groove 29 Bottom 31 Base layer 32 Tin layer A Axial direction

Claims

1. a core having a winding core portion extending in an axial direction and a first flange portion and a second flange portion provided at a first end portion and a second end portion, respectively, opposite to each other in the axial direction of the winding core portion; a first terminal electrode and a second terminal electrode provided on the first flange portion and the second flange portion, respectively; at least one wire wound around the winding core while being connected between the first terminal electrode and the second terminal electrode; Equipped with each of the first flange portion and the second flange portion has a mounting surface facing a mounting substrate during mounting, an inner end surface facing the winding core portion, and an outer end surface opposite to the inner end surface; each of the first terminal electrode and the second terminal electrode includes a base layer and a tin layer containing tin; the base layer is provided so as to extend to the mounting surface and to a portion of each of the inner end surface and the outer end surface, the tin layer is provided so as to cover the base layer and to form at least an outermost layer of each of the first terminal electrode and the second terminal electrode, a direction away from the mounting surface along a direction in which the inner end surface and the outer end surface extend is defined as a height direction, With respect to at least one of the first terminal electrode and the second terminal electrode, when a cross section of a connection portion between the wire and the terminal electrode is viewed perpendicular to the mounting surface, the inner end surface, and the outer end surface, (1) a position in the height direction of a tip of a portion of the base layer extending along the inner end surface is higher than a position in the height direction of a tip of a portion of the base layer extending along the outer end surface; (2) The tin layer has a tip end of a portion extending along the inner end surface that is lower in the height direction than a tip end of a portion extending along the outer end surface. Coil parts.

2. 2. The coil component according to claim 1, wherein at least one of the first flange portion and the second flange portion on which the at least one terminal electrode is provided has a groove provided on the mounting surface, the groove defining a bottom surface extending in a direction connecting the inner end face and the outer end face and having a gradient that becomes deeper from the outer end face side toward the inner end face side, and the wire is connected to the terminal electrode at the bottom surface of the groove.

3. 2. The coil component according to claim 1, wherein, in at least one of the first terminal electrodes, all of the height-direction positions of a tip of a portion of the base layer extending along the inner end face are higher than all of the height-direction positions of a tip of a portion of the base layer extending along the outer end face, and all of the height-direction positions of a tip of a portion of the tin layer extending along the inner end face are lower than all of the height-direction positions of a tip of a portion of the tin layer extending along the inner end face.

4. The coil component according to claim 1 , wherein the underlayer is a baked layer of a conductive paste containing silver as a conductive component.

5. The coil component according to claim 1 , wherein the tin layer is a plating layer.

6. The coil component according to claim 1 , wherein the at least one terminal electrode is both the first terminal electrode and the second terminal electrode.

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