coil components

Abstract

The present invention provides a coil component that is less prone to poor contact between the end of the core wire and the terminal electrode. The wire (21) includes a core wire (29) made of copper or a copper alloy and an insulating film made of resin covering its periphery. The terminal electrode (17) has a nickel-containing layer (33) made of nickel or a nickel alloy that covers the bottom surface of a flange portion, and a tin-containing layer (34) made of tin or a tin alloy located thereon. The end (21a) of the core wire (29) of the wire (21) has a contact surface (37) that contacts the nickel-containing layer (33), a pair of side surfaces (38, 39) extending in a direction from the nickel-containing layer (33), and a top surface (40) opposite to the contact surface (37). The side surfaces (38, 39) of the end (21a) have a region (35) that does not contact the tin-containing layer (34) at least on the top surface (40) side. In this region (35), the copper of the core wire (29) will not diffuse into the tin-containing layer (34), which makes the core wire (29) less likely to become thin.

Description

Technical Field

[0001] The present invention relates to a wound coil component having a wire wound in the core portion, and particularly to a connection structure between the wire and the terminal electrode. Background Technology

[0002] As a technology related to this invention, for example, there is the technology described in Japanese Patent Application Publication No. 10-312922 (Patent Document 1). In Patent Document 1, a coil component having a structure in which wires and terminal electrodes are connected by thermoforming is described. Figure 9 It is cited from Patent Document 1, and is equivalent to the content in Patent Document 1. Figure 1 (C). Figure 9 A cross-section of a portion of a flange 2 of the core 1 is shown.

[0003] like Figure 9 As shown, a terminal electrode 4 is provided on the bottom surface 3 of the flange portion 2 facing the mounting surface. The terminal electrode 4 includes, for example, a layer of highly conductive material 5 made of silver or a silver alloy, a solder-resistant material layer 6 made of nickel or the like thereon, and a solder-friendly material layer 7 made of tin or a tin alloy thereon. Although not shown, the wire is configured to have a core wire made of copper or a copper alloy and an insulating film made of resin covering its periphery. Figure 9 In the middle, the end 8 of the core wire of the wire wound around the core (not shown) is connected to the terminal electrode 4 by thermo-pressing.

[0004] In the above-described thermoforming process, the end 8 of the wire core is positioned on the terminal electrode 4. In this state, a heating element (not shown) is used to press the end 8 of the core towards the terminal electrode 4. As a result, the end 8 of the core is flattened, making its cross-section flat, and is embedded in a position that is approximately flush with the surface of the solder-affinity layer 7. Thus, the desired bonding state is achieved between the end 8 of the core and the terminal electrode 4.

[0005] Patent Document 1: Japanese Patent Application Publication No. 10-312922

[0006] It is known that with advancements in core miniaturization, wire diameter diversification (thicker wires, thinner wires), and high heat resistance of wire insulation coatings, as well as changes in requirements such as increased reliability testing loads, even when connecting the core wire terminal 8 to the terminal electrode 4 via thermocompression bonding as described in Patent Document 1, the desired connection state sometimes cannot be achieved. For example, this can sometimes lead to poor bonding between the core wire terminal 8 and the terminal electrode 4, or the core wire breaking near the terminal electrode 4.

[0007] Furthermore, coil components typically have at least two terminal electrodes, with the wire end connected to each of these terminal electrodes. Therefore, ideally, all terminal electrodes would be connected to the wire end to address the aforementioned problem. However, even if only one terminal electrode is connected to one end of the wire, it should be considered an improvement over a completely unsolved problem. Summary of the Invention

[0008] Therefore, the object of the present invention is to provide a coil component that is less prone to poor connection between the end of the core wire and the terminal electrode, and less prone to core wire breakage.

[0009] The present invention relates to a coil component comprising: a core, including a core portion extending along an axial direction, and a first flange portion and a second flange portion respectively disposed at opposite ends in the axial direction of the core portion; a first terminal electrode disposed on the first flange portion; a second terminal electrode disposed on the second flange portion; and at least one wire wound around the core portion, including a core wire made of copper or a copper alloy and an insulating film made of resin covering its periphery.

[0010] The core wire of the wire has a first terminal electrically connected to a first terminal electrode and a second terminal electrically connected to a second terminal electrode.

[0011] The first flange portion and the second flange portion have a bottom surface facing the mounting surface side.

[0012] The first terminal electrode and the second terminal electrode have a nickel-containing layer made of nickel or a nickel alloy and a tin-containing layer made of tin or a tin alloy located thereon, wherein the nickel-containing layer is configured to cover the bottom surface of the first flange portion and the second flange portion respectively.

[0013] The first terminal and the second terminal each have: a contact surface in contact with a nickel-containing layer; a pair of side surfaces adjacent to the contact surface and extending in a direction from which the nickel-containing layer rises; and a top surface adjacent to the side surfaces and facing the contact surface.

[0014] In this invention, the characteristic is that, since the tin contained in the tin-containing layer in the terminal electrode forms an alloy with the copper contained in the core wire of the wire, it is necessary to be aware of the phenomenon that copper on the wire side diffuses into the tin-containing layer of the terminal electrode at high temperatures, for example, during hot pressing, resulting in the core wire of the wire becoming thinner. In order to solve the above problem, at least one of the terminals of the first terminal and the second terminal has a side surface that does not contact the tin-containing layer, at least on the top surface side.

[0015] According to the present invention, since the side surface of the core wire terminal has a region that does not contact the tin-containing layer in the terminal electrode, at least on the top surface side, copper diffusion into the tin-containing layer will not occur in the region of the core wire terminal that does not contact the tin-containing layer. Therefore, it is less likely that the copper contained in the core wire will diffuse into the tin-containing layer in the terminal electrode due to heat applied, for example, during thermoforming or use in a high-temperature environment of the coil component, causing the core wire to become thinner. Therefore, poor bonding between the core wire terminal and the terminal electrode and core wire breakage are less likely to occur. Attached Figure Description

[0016] Figure 1 This is a bottom view of the coil component 11 according to the first embodiment of the present invention.

[0017] Figure 2 yes Figure 1 The right side view of the coil component 11 shown.

[0018] Figure 3 This is a schematic enlarged view showing the cross-section of wire 21.

[0019] Figure 4 It is a schematic enlargement showing along Figure 1 A diagram of a portion of the cross section of line SS.

[0020] Figure 5 This is a schematic, further enlarged illustration. Figure 4 The diagram shows a portion of the image.

[0021] Figure 6 It is shown schematically from above. Figure 4 The diagram shows a portion of the image.

[0022] Figure 7 This is used to illustrate the second embodiment of the present invention. Figure 5 The corresponding diagram.

[0023] Figure 8 This is used to illustrate the third embodiment of the present invention. Figure 5 The corresponding diagram.

[0024] Figure 9 It is cited from Patent Document 1, and is equivalent to the content in Patent Document 1. Figure 1 (C) indicates a portion of a flange 2 of the core 1.

[0025] Explanation of reference numerals in the attached figures

[0026] 11…coil component; 12…core portion; 13, 14…flange portion; 15…core body; 17-20…terminal electrodes; 21, 22…wire; 21a, 21b, 22a, 22b…terminals; 23, 24…bottom surface; 29…core wire; 30…insulating coating; 33…nickel layer; 34…tin layer; 35…area not in contact with tin layer; 37…contact surface; 38, 39…side surface; 40…top surface; 41…solder foot; 42…concave surface; 43…melted solidified material; AX…axial direction; W1…width dimension of the terminal; W2…width dimension of the gap between the tin layer and the terminal; H1…height dimension of the terminal; H2…height dimension of the area where the solder foot contacts the side; H3…height dimension of the tin layer. Detailed Implementation

[0027] Reference Figure 1 and Figure 2 The coil component 11, for example, constitutes a common-mode choke coil and includes a core 15. The core 15 has: a winding core portion 12 extending along the axial direction AX; and a first flange portion 13 and a second flange portion 14, respectively disposed at opposite ends in the axial direction AX of the winding core portion 12. The core 15, for example, has a dimension of approximately 3.2 mm in the axial direction AX, and its width in the direction orthogonal to the axial direction (…). Figure 1 The vertical dimension is approximately 2.5mm, and the height dimension is approximately 2.5mm. Figure 1 The dimension of the core (in the direction perpendicular to the paper surface) is approximately 1.5 mm. The core 15 is made of non-conductive materials such as alumina or ferrite.

[0028] The coil component 11 also includes a top plate 16 that connects the pair of flanges 13 and 14 of the core 15. If both the core 15 and the top plate 16 are made of magnetic material, the top plate 16 can work in conjunction with the core 15 to form a closed magnetic circuit with magnetic flux surrounding it.

[0029] A first terminal electrode 17 and a third terminal electrode 19 are provided on the first flange portion 13. A second terminal electrode 18 and a fourth terminal electrode 20 are provided on the second flange portion 14.

[0030] The first wire 21 and the second wire 22 are wound around the core 12 in the same direction. For example... Figure 3 As shown in the enlarged cross-section of the first wire 21, both the first wire 21 and the second wire 22 include a core wire 29 made of copper or a copper alloy and an insulating film 30 covering its periphery made of a resin such as imide-modified polyurethane. For example, wires 21 and 22 may be used with a core wire 29 having a diameter of 0.030 mm and an insulating film 30 having a thickness of 0.010 mm.

[0031] like Figure 1As shown, the core wire 29 of the first wire 21 has a first terminal 21a electrically connected to the first terminal electrode 17 and a second terminal 21b electrically connected to the second terminal electrode 18. The core wire 29 of the second wire 22 has a third terminal 22a electrically connected to the third terminal electrode 19 and a fourth terminal 22b electrically connected to the fourth terminal electrode 20.

[0032] The first flange portion 13 has a first bottom surface 23 facing the mounting surface side. The second flange portion 14 has a second bottom surface 24 facing the mounting surface side.

[0033] A first terminal electrode 17 is disposed on a first bottom surface 23 and is configured to extend from the first bottom surface 23 to a portion of each of a plurality of adjacent surfaces. A second terminal electrode 18 is disposed on a second bottom surface 24 and is configured to extend from the second bottom surface 24 to a portion of each of a plurality of adjacent surfaces. The first terminal electrode 17 has a first main surface 25 extending along the first bottom surface 23. The second terminal electrode 18 has a second main surface 26 extending along the second bottom surface 24.

[0034] The third terminal electrode 19 is disposed on the first bottom surface 23 at a predetermined interval relative to the first terminal electrode 17, and is configured to extend from the first bottom surface 23 to a portion of each of a plurality of adjacent surfaces. The fourth terminal electrode 20 is disposed on the second bottom surface 24 at a predetermined interval relative to the second terminal electrode 18, and is configured to extend from the second bottom surface 24 to a portion of each of a plurality of adjacent surfaces. The third terminal electrode 19 has a third main surface 27 extending along the first bottom surface 23. The fourth terminal electrode 20 has a fourth main surface 28 extending along the second bottom surface 24.

[0035] Figure 4 A magnified view shows the cross-sectional structure of the first terminal electrode 17 positioned to cover the first bottom surface 23. Furthermore, the cross-sectional structures of the second terminal electrode 18, the third terminal electrode 19, and the fourth terminal electrode 20 are substantially the same as those of the first terminal electrode 17. Therefore, the cross-sectional structure of the first terminal electrode 17 will be described in detail below, while the descriptions of the cross-sectional structures of the second terminal electrode 18, the third terminal electrode 19, and the fourth terminal electrode 20 will be omitted.

[0036] The first terminal electrode 17 has: a sintered electrode layer 31 located on the first bottom surface 23 of the first flange portion 13, formed, for example, by sintering a conductive paste containing silver as a conductive component; a copper-containing layer 32 formed thereon by wet plating; a nickel-containing layer 33 formed thereon by wet plating; and a tin-containing layer 34 formed thereon by wet plating. The copper-containing layer 32, formed by wet plating, mainly imparts good conductivity, the nickel-containing layer 33 mainly imparts solder resistance, and the tin-containing layer 34 mainly imparts good solder affinity and good connection with solder.

[0037] Furthermore, not only the copper layer 32, but also the sintered electrode layer 31 possesses good electrical conductivity. Therefore, either the copper layer 32 or the sintered electrode layer 31 can be omitted. In addition, the copper layer 32, the nickel layer 33, and the tin layer 34 can also be formed by methods other than wet plating.

[0038] Although not shown in the figure, in the portion of the first terminal electrode 17 disposed on each of the plurality of surfaces adjacent to the first bottom surface 23, a nickel-chromium layer and a nickel-copper layer formed by dry plating such as sputtering are respectively provided as a substrate, and the copper-containing layer 32, the nickel-containing layer 33 and the tin-containing layer 34 extend from the first bottom surface 23 thereon.

[0039] Figure 4 This indicates that the first terminal 21a of the core wire 29 of the first wire 21 is connected to the first terminal electrode 17. During this connection, thermoforming is applied. In the thermoforming process, the first wire 21 is positioned on the first terminal electrode 17, and in this state, a heating element (not shown) is used to press the first wire 21 toward the first terminal electrode 17. As a result, the insulating film 30 of the first wire 21 (see reference)... Figure 3 The core wire 29 melts or decomposes, exposing at least a portion of its first terminal 21a. Simultaneously, at least a portion of the first terminal 21a is embedded within the first terminal electrode 17, and more specifically, within the tin-containing layer 34, until the first terminal 21a is flattened, its cross-section becoming flat, and it contacts the nickel-containing layer 33. Thus, the first terminal 21a of the first wire 21 is electrically connected to the first terminal electrode 17.

[0040] Figure 5 Further magnification shows Figure 4Part of the portion shown. The first terminal 21a of the core wire 29 of the first wire 21 is flattened into a flat cross-section by thermoforming, resulting in a state having a contact surface 37 that contacts the nickel-containing layer 33, a pair of side surfaces 38 and 39 that are adjacent to the contact surface 37 and extend in the direction from the nickel-containing layer 33, and a flat top surface 40 that is adjacent to the side surfaces 38 and 39 and opposite the contact surface 37.

[0041] Hereinafter, the direction connecting the contact surface 37 and the top surface 40 will be taken as the height direction, and the direction connecting the pair of side surfaces 38 and 39 will be taken as the width direction.

[0042] As the first wire 21, a wire with a core wire 29 having a diameter of, for example, 30 μm is used. In this case, as a result of thermoforming, the width dimension W1 of the first terminal 21a of the core wire 29, which is flattened into a flat cross-section, is approximately 40 μm, representing an increase of approximately +33%. On the other hand, the height dimension H1 of the first terminal 21a of the core wire 29 is approximately 15 μm, representing a decrease of approximately -50%.

[0043] In addition, such as Figure 5 As shown, the sides 38 and 39 of the first terminal 21a have regions 35 that do not contact the tin-containing layer 34, at least on the top surface 40 side. More specifically, the tin-containing layer 34 forms solder feet 41 whose height dimension gradually decreases towards each of the pair of sides 38 and 39 of the first terminal 21a. In this embodiment, the solder feet 41 contact the lower ends of the sides 38 and 39 of the first terminal 21a as shown in the figure. Preferably, the area where the solder feet 41 contact the sides 38 and 39 of the first terminal 21a is less than half the height dimension of the sides 38 and 39.

[0044] With the configuration described above, copper diffusion into the tin-containing layer 34 will not occur in the region 35 of the first terminal 21a of the core wire 29, where it is at least not in contact with the tin-containing layer 34. Therefore, defects such as thinning of the core wire 29 are less likely to occur. On the other hand, since there is a tin-containing surface of the tin-containing layer 34 with high affinity for solder around the first terminal electrode 17, good connection between the coil component 11 and the mounting substrate can be maintained.

[0045] In addition, by having solder feet 41, the unevenness of the first terminal electrode 17 relative to the first main surface 25 is reduced, so the wetting and spreading of solder paste during the installation of the coil component 11 is less likely to be hindered, and the instability of the posture of the coil component 11 is less likely to occur.

[0046] like Figure 5 As shown, the outward-facing surface of solder leg 41 forms a downward-convex curved surface, i.e., a concave curved surface 42. Figure 5In the diagram, a molten solidified material 43 is illustrated in the space defined by the concave curved surface 42 and the side surfaces 38 and 39 of the first terminal 21a. This molten solidified material 43 is a resin block derived from the resin constituting the insulating film 30 of the first wire 21. It is formed by the melting of the insulating film 30 during hot pressing, with at least a portion of the melt remaining in the aforementioned space and solidifying. Furthermore, in Figure 4 And then Figure 6 The illustration of the molten solidified material 43 is omitted in the text.

[0047] The formation of the aforementioned molten solidified material 43 has the following effect. During hot-press bonding, as described above, the insulating film 30 melts, and the tin-containing layer 34 also melts in and around the portion in contact with the first wire 21. At this time, as hot-press bonding conditions, a lower temperature but a higher pressure is preferred. As a result, the tin or tin alloy constituting the tin-containing layer 34 melts in and around the portion in contact with the first wire 21, while being pushed away by the molten solidified material 43 generated by the melting of the insulating film 30. Then, the sides 38 and 39 of the first terminal 21a become a state in which at least on the top surface 40 side, there is a region 35 that does not contact the tin-containing layer 34, and the tin-containing layer 34 becomes a state in which the dimension in the height direction gradually decreases towards each of the pair of sides 38 and 39 of the first terminal 21a.

[0048] In addition, the insulating film 30 melts to form a molten solidified product 43, but not all of the molten resin formed by the melting of the insulating film 30 becomes the molten solidified product 43, but some of it may decompose and vaporize.

[0049] In addition, the top surface 40 of the first terminal 21a is usually exposed to the outside, but sometimes the molten solidified material of the insulating film 30 also remains slightly on a part of the top surface 40.

[0050] Figure 5 The embodiments shown also have the following features.

[0051] The height dimension H2 of the area where the solder foot 41 contacts the sides 38 and 39 of the first terminal 21a is less than half of the width dimension W1 of the first terminal 21a. Therefore, even if the copper on the sides 38 and 39 of the first terminal 21a is slightly corroded by the tin-containing layer 34, the reliability of the electrical connection between the first terminal 21a and the nickel-containing layer 33 can be maintained.

[0052] Furthermore, the height dimension H3 of the portion of the tin-containing layer 34 excluding the solder pad 41 is smaller than the height dimension H1 of the first terminal 21a. As a result, it is easy to further reduce the height dimension H2 of the area where the solder pad 41 contacts the sides 38 and 39 of the first terminal 21a, that is, it is easy to further expand the area 35 of the sides 38 and 39 of the first terminal 21a that does not contact the tin-containing layer 34.

[0053] Furthermore, the width dimension W2 of the portion of the tin-containing layer 34 excluding the solder pad 41 and the first terminal 21a is smaller than the width dimension W1 of the first terminal 21a. As a result, the unevenness of the first terminal electrode 17 relative to the first main surface 25 is further reduced, thus making it less likely for the solder paste to wet and spread during the mounting of the coil component 11 to be hindered, and making it less likely for the coil component 11 to become unstable in posture.

[0054] In addition, such as Figure 6 As shown, viewed from a direction orthogonal to the first bottom surface 23 of the first flange portion 13, the region 35 where the first terminal 21a does not contact the tin-containing layer 34 (in) Figure 6 (A portion of the area shown on the white background) is positioned along the entire outline of the first terminal 21a located on the nickel-containing layer 33.

[0055] Therefore, copper diffusion into the tin-containing layer 34 is less likely to occur along the entire outline of the first terminal 21a, thereby making it more reliable to prevent the defect of thinning of the core wire 29. Furthermore, since there is a tin-containing surface of the tin-containing layer 34 with high affinity for solder around the first terminal electrode 17 and the first terminal 21a, the high connectivity of the coil component 11 relative to the mounting substrate can be maintained more reliably.

[0056] Reference Figure 7 The second embodiment of the present invention will be described. Figure 7 Is with Figure 5 The corresponding diagram. In Figure 7 In the middle, to and Figure 5 Elements that are equivalent to those shown are labeled with the same reference numerals as those in the attached drawings, and repeated descriptions are omitted.

[0057] Figure 7 The illustrated embodiment is characterized in that the solder pad 41 does not contact the sides 38 and 39 of the first terminal 21a; in other words, the entire area of ​​sides 38 and 39 is a region 35 that does not contact the tin-containing layer 34. This structure behaves, for example, as a molten solidified product 43 during thermoforming. Figure 5 The different results achieved in the illustrated embodiments are as follows. That is, it is achieved by the molten solidified material 43 generated by the melting of the insulating coating 30 during hot pressing, which pushes the molten tin or tin alloy more far away.

[0058] According to this structure, there is no tin contained in the tin-containing layer 34 around the entire periphery of the first terminal 21a. Therefore, corrosion of the copper contained in the first terminal 21a by the tin-containing layer 34 can be completely prevented, thus maintaining a highly reliable connection between the first wire 21 and the first terminal electrode 17. In addition, in this structure, the first terminal 21a is electrically connected to the nickel-containing layer 33.

[0059] Reference Figure 8 The third embodiment of the present invention will be described. Figure 8 Is with Figure 5 The corresponding diagram. In Figure 8 In the middle, to and Figure 5 Elements that are equivalent to those shown are labeled with the same reference numerals as those in the attached drawings, and repeated descriptions are omitted.

[0060] Figure 8 The illustrated embodiment is characterized in that the behavior of the molten solidified material 43 is similar to... Figure 7 The behavior of the molten solidified product 43 shown is substantially the same, but a residue 44 of the tin-containing layer 34 exists at each corner defined by the sides 38 and 39 of the first terminal 21a and the surface of the nickel-containing layer 33. Figure 8 In the embodiments shown, with Figure 7 Similarly, in the embodiment shown, solder feet 41 do not contact the sides 38 and 39 of the first terminal 21a, but the residue 44 slightly contacts the sides 38 and 39.

[0061] According to this structure, the residue 44 of the tin-containing layer 34 has almost no effect on the diffusion of copper contained in the first terminal 21a, and therefore can be expected to have a similar effect to... Figure 7 The illustrated embodiment achieves essentially the same effect. Furthermore, in this structure, the first terminal 21a is electrically connected to the nickel-containing layer 33.

[0062] In addition, the above Figure 6 The features shown are preferably those described above. Figure 7 and Figure 8 The embodiments shown also include this feature.

[0063] The above reference Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 The description pertains to the first terminal electrode 17 and the first terminal 21a of the first wire 21. The invention also relates to the case where this connection configuration is applied only to the connection portion of the terminal electrode and the terminal of one of the wires, but preferably to the connection portions of all terminal electrodes and the terminals of all wires connected thereto.

[0064] The present invention has been described above in connection with the illustrated embodiments, but various other modifications are possible within the scope of the present invention.

[0065] For example, in the illustrated implementation, such as Figure 5 , Figure 7 as well as Figure 8 As illustrated, the behavior of the molten solidified material 43 generated by the insulating film 30 results in a state where the sides 38 and 39 of the first terminal 21a have a region 35 that does not contact the tin-containing layer 34, at least on the top surface 40 side. However, to achieve this state, methods other than those using the molten solidified material 43 can also be applied. For example, a recess or opening can be pre-formed in the portion of the terminal of the core wire to be disposed in the tin-containing layer, and the terminal of the core wire can be disposed in alignment with the recess or opening and then thermo-pressed together.

[0066] In addition, in the above cases, the solder feet can be pre-formed in the same way as the formation of the recess or opening.

[0067] Furthermore, while the illustrated embodiment relates to a coil component with two wires, the present invention can also be applied to coil components with one wire or three or more wires. Therefore, the number of terminal electrodes can be varied depending on the number of wires.

[0068] Additionally, the coil component 11 includes a top plate 16 connecting a pair of flanges 13 and 14. However, a coating material may also be applied to cover the core portion 12 and the wires 21 and 22 on the side opposite to the bottom surfaces 23 and 24 of the respective flanges 13 and 14. A resin containing magnetic powder is preferably used as the coating material. Alternatively, either the top plate 16 or the coating material may be omitted from the coil component 11.

[0069] Furthermore, the embodiments described in this specification are illustrative, and structural substitutions or combinations can be made between different embodiments.

Claims

1. A coil component, wherein, have: The core includes a core portion extending along an axial direction, a first flange portion, and a second flange portion, wherein the first flange portion and the second flange portion are respectively disposed at a first end and a second end opposite to each other in the axial direction of the core portion; The first terminal electrode is disposed on the first flange portion; The second terminal electrode is disposed on the second flange portion; as well as At least one wire is wound around the core portion, including a core wire made of copper or a copper alloy and an insulating film made of resin covering its periphery. The core wire of the wire has a first terminal electrically connected to the first terminal electrode and a second terminal electrically connected to the second terminal electrode. The first flange portion and the second flange portion each have a bottom surface facing the mounting surface side. The first terminal electrode and the second terminal electrode each have a nickel-containing layer made of nickel or a nickel alloy and a tin-containing layer made of tin or a tin alloy thereon, wherein the nickel-containing layer is configured to cover the bottom surface of each of the first flange portion and the second flange portion. The first terminal and the second terminal each have: a contact surface in contact with the nickel-containing layer; a pair of side surfaces adjacent to the contact surface and extending in a direction from which the nickel-containing layer rises; and a top surface adjacent to the pair of side surfaces and facing the contact surface. The pair of side surfaces of at least one of the first terminal and the second terminal have areas that do not contact the tin-containing layer, at least on the top surface side.

2. The coil component according to claim 1, wherein, When the direction connecting the contact surface and the top surface is taken as the height direction, the solder layer has solder feet whose height dimension gradually decreases as it approaches each of the pair of sides of the terminal.

3. The coil component according to claim 2, wherein, The solder foot contacts at least one side of the pair of sides of the terminal.

4. The coil component according to claim 3, wherein, The area where the solder foot contacts the side of the terminal is less than 1 / 2 of the dimension in the height direction of the pair of side surfaces.

5. The coil component according to claim 3 or 4, wherein, When the direction connecting the pair of sides is taken as the width direction, the dimension of the area in the height direction of the region where the solder foot contacts the side of the terminal is less than 1 / 2 of the dimension in the width direction of the terminal.

6. The coil component according to claim 2, wherein, The solder feet do not contact at least one of the pair of sides of the terminal.

7. The coil component according to any one of claims 2 to 4, wherein, It also includes a molten solidified material, which, when the direction connecting the pair of sides is taken as the width direction, is located outside the width direction of the side of the terminal and originates from the insulating film.

8. The coil component according to any one of claims 2 to 4, wherein, The height dimension of the portion of the tin-containing layer excluding the solder pads is smaller than the height dimension of the terminal.

9. The coil component according to any one of claims 1 to 4, wherein, When the direction connecting the pair of sides is taken as the width direction, the dimension of the width direction of the interval between the portion of the tin-containing layer excluding the solder pads and the terminal is smaller than the dimension of the width direction of the terminal.

10. The coil component according to any one of claims 1 to 4, wherein, When viewed from a direction orthogonal to the bottom surface, the area of ​​the terminal that does not contact the tin-containing layer is positioned along the entire outline of the terminal located on the nickel-containing layer.

Images