Coil component

Abstract

Provided is a coil component having a configuration that makes it difficult for a center wire of a wire to break and that can reduce adverse conditions caused by deterioration of an insulating coating. An inclined surface (47) is provided at a boundary portion of a mounting surface (31) and an inner end surface (27) of a flange portion (23). A terminal electrode (41) has a first electrode portion (41a) provided along the mounting surface (31) and a second electrode portion (41b) provided along the inclined surface (47) so as to extend from the first electrode portion (41a) to a point on the way to the inclined surface (47). The wire (39) is electrically and mechanically connected at both the first electrode portion (41a) and the second electrode portion (41b). The diameter (WD) of the wire (39) on the winding core portion (22) is larger than the height direction dimension (EH) of the second electrode portion (41b), and the depth direction dimension (SD) of the inclined surface (47) is larger than the diameter (WD) of the wire (39).

Description

Technical Field

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

[0002] For example, Japanese Patent Application Publication No. 2009-272315 (Patent Document 1) describes a wound coil component in which the ends of the wire are connected to terminal electrodes by thermoforming, and the terminal electrodes are respectively provided on the flanges at both ends of the drum-shaped core.

[0003] Figure 9 A portion of the flange 2 located at one end of the drum-shaped core 1 is shown under magnification. Figure 9 In the diagram, (A) is a top view showing the flange 2 from the mounting surface 3 side facing the mounting substrate side during installation, and (B) is a cross-sectional view along line 9B-9B of (A).

[0004] exist Figure 9 A terminal electrode 4 is provided on the mounting surface 3 facing the mounting substrate side of the flange portion 2 shown in the diagram. The terminal electrode 4, for example, includes an Ag layer 5 formed by sintering a conductive paste containing Ag as a conductive component, and a Cu layer 6, a Ni layer 7, and a Sn layer 8 sequentially formed thereon by plating. The Sn layer 8 on the surface of the terminal electrode 4 provides good solderability during mounting. Furthermore, in... Figure 9 In (B), the thickness of the terminal electrode 4 is exaggerated in order to clearly illustrate each of the Ag layer 5, Cu layer 6, Ni layer 7 and Sn layer 8.

[0005] On the other hand, although not shown, the wire 10 is wound in a spiral shape around the core portion 9 of the core body 1. The illustrated end of the wire 10 is electrically and mechanically connected to the aforementioned terminal electrode 4. The wire 10, for example, includes a linear central wire 10a made of copper wire and an insulating film 10b covering the central wire 10a, made of an electrically insulating resin such as polyurethane or polyimide.

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-272315

[0007] To connect the wire 10 to the terminal electrode 4, a thermoforming process is used to press the end of the wire 10 toward the terminal electrode 4 using a heating element. To achieve a sufficient and proper thermoforming of the wire 10 relative to the terminal electrode 4, a sufficiently high temperature and pressure need to be applied to the wire 10 to cause appropriate plastic deformation.

[0008] However, as a result of the pressure applied during the hot-pressing process, stress is concentrated in the area near the ridge line where the mounting surface 3 of the flange 2 intersects with the inner end face 11, and the wire 10 is prone to breakage in this area.

[0009] Furthermore, the insulating film 10b of the wire 10 is decomposed and removed due to the heat during the thermoforming process. Figure 9 In this context, the portion of the insulating film 10b that has been removed by hot-pressing (hereinafter, "removed portion") is designated as "R1". Furthermore, near the removed portion R1 of the insulating film 10b, there exists a portion of the insulating film 10b that deteriorates even if it is not removed by the heat generated by the hot-pressing. Figure 9 In this context, the portion of the insulating film 10b that deteriorates due to the heat generated by the hot-pressing bonding (hereinafter, "deteriorated portion") is designated as "R2". The deteriorated portion R2 is deficient in terms of reliability regarding electrical insulation.

[0010] like Figure 9 As shown, the aforementioned deteriorated portion R2 protrudes towards the inner end face 11 away from the flange portion 2. This protrusion of the deteriorated portion R2 increases the probability of accidental contact with electrical components other than the wire 10, such as other wires. While Patent Document 1 only describes a coil component constituting a single coil, in the case of a wound coil component with multiple wires, such as a common-mode choke coil, the possibility of the protruding deteriorated portion R2 causing a short circuit between adjacent wires cannot be ruled out.

[0011] Furthermore, the deterioration of the insulation film 10b of the wire 10, which leads to the formation of the deteriorated portion R2, accelerates the oxidation of the central wire 10a of the wire 10. At this time, if the central wire 10a of the wire 10 is thin or fine, the proportion of the oxidized portion increases, sometimes causing the wire 10 to break. Summary of the Invention

[0012] Therefore, the object of the present invention is to provide a coil component having a structure that makes it less likely for the center wire of the coil to break and reduces adverse conditions caused by the deterioration of the insulating coating.

[0013] The present invention relates to a coil component comprising: a core having a winding core portion and flange portions disposed at both ends of the winding core portion in the axial direction; a wire wound around the winding core portion; and terminal electrodes disposed on the flange portions for electrically and mechanically connecting the ends of the wire.

[0014] The flange portion has: an inner end face facing the core portion and for mounting the end of the core portion in the axial direction; an outer end face facing the opposite side of the inner end face; a mounting surface connecting the inner end face and the outer end face and facing the mounting substrate side during mounting; and a top surface facing the opposite side of the mounting surface.

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

[0016] A bevel is provided at the boundary between the mounting surface and the inner end face of the flange portion. The bevel extends in such a way that it connects a first intermediate position located between the inner end face and the outer end face in the direction along the mounting surface, and a second intermediate position located between the mounting surface and the top surface in the direction along the inner end face.

[0017] The terminal electrode described above has a first electrode portion disposed along the mounting surface and a second electrode portion disposed along the inclined surface, extending from the first electrode portion to the inclined surface.

[0018] The wire is electrically and mechanically connected to both the first electrode portion and the second electrode portion.

[0019] The diameter of the wire on the core portion is larger than the height dimension of the second electrode portion measured in a direction orthogonal to the mounting surface, and the depth dimension of the inclined plane, measured in a direction orthogonal to the mounting surface, from the first intermediate position to the second intermediate position, is larger than the aforementioned diameter of the wire.

[0020] According to the coil component of the present invention, since a bevel is provided on the flange portion of the core, the terminal electrode has a first electrode portion disposed along the mounting surface of the flange portion and a second electrode portion disposed from the first electrode portion along the bevel, and the wire is electrically and mechanically connected to both the first electrode portion and the second electrode portion, thereby improving the connection reliability between the terminal electrode and the wire, and during thermoforming, it can alleviate the stress concentration on the wire at the portion near the ridge line where the mounting surface of the flange portion intersects with the inner end face, making it less likely for wire breakage to occur at that portion.

[0021] Furthermore, since the diameter of the wire on the core portion, i.e., the original diameter of the wire before thermoforming, is larger than the height dimension of the second electrode portion, and the depth dimension of the bevel is larger than the aforementioned diameter of the wire, it is possible to prevent crimping of a portion of the wire located on the bevel during thermoforming. Therefore, the area where the insulation coating is removed from the wire can be reduced, and the wire thickness near the portion where the insulation coating is removed can be ensured. As a result, wire breakage near the portion where the insulation coating is removed is less likely to occur.

[0022] Furthermore, since the wire connected to the terminal electrode is electrically and mechanically connected not only to the first electrode portion disposed along the mounting surface of the flange, but also to the second electrode portion disposed along the inclined surface, the wire can be positioned along the inclined surface. Therefore, the degree to which deteriorated portions of the insulation film of the wire, which may be caused by thermoforming, protrude away from the inner end face of the flange, can be reduced. As a result, even if deterioration occurs in the insulation film during thermoforming, reliability in preventing electrical short circuits can be ensured.

[0023] Furthermore, since the second electrode portion in the terminal electrode only extends to the middle of the slope, meaning there is a portion where no electrode is formed on the second middle position of the slope, the wire connected to the terminal electrode is separated from the slope. Therefore, during thermoforming, the insulating film will not collide with the core and deform, maintaining its original shape. Consequently, the resistance to corrosion of the wire caused by flux and moisture is improved. Attached Figure Description

[0024] Figure 1 Enlarged view of a portion of the first flange portion 23 at one end of the core 25 of the coil component 21 of the first embodiment of the present invention, (A) is a top view of the first flange portion 23 from the mounting surface 31 side facing the mounting substrate side during installation, and (B) is a cross-sectional view along line 1B-1B of (A).

[0025] Figure 2 It is shown with mounting surfaces 31 and 32 facing upwards. Figure 1 A perspective view of the overall appearance of the core 25 of the coil component 21 shown.

[0026] Figure 3 It is magnified in Figure 2 The diagram shows a perspective view of the inclined surface 47 and its surrounding area of ​​the first flange portion 23 of the core 25.

[0027] Figure 4 This is a perspective view showing the overall appearance of the core 25a of the coil component according to the second embodiment of the present invention with the mounting surfaces 31 and 32 facing upwards.

[0028] Figure 5 This is a perspective view showing the overall appearance of the core 25b of the coil component according to the third embodiment of the present invention with the mounting surfaces 31 and 32 facing upwards.

[0029] Figure 6 This is a perspective view showing the overall appearance of the core 25c of the coil component according to the fourth embodiment of the present invention with the mounting surfaces 31 and 32 facing upwards.

[0030] Figure 7This is a perspective view showing the overall appearance of the core 25d of the coil component according to the fifth embodiment of the present invention with the mounting surfaces 31 and 32 facing upwards.

[0031] Figure 8 This is a perspective view showing the overall appearance of the core 25e of the coil component according to the sixth embodiment of the present invention with the mounting surfaces 31 and 32 facing upwards.

[0032] Figure 9 A portion of the flange portion 2 at one end of the core 1 of the coil component described in Patent Document 1 is shown in an enlarged view. (A) is a top view of the flange portion 2 from the mounting surface 3 side facing the mounting substrate side during installation, and (B) is a cross-sectional view along line 9B-9B of (A).

[0033] Explanation of reference numerals in the attached figures

[0034] 21…coil component; 22…core portion; 23…first flange portion; 24…second flange portion; 25, 25a-25e…core body; 27, 28…inner end face; 29, 30…outer end face; 31, 32…mounting surface; 33, 34…top surface; 39…wire; 39a…center wire; 39b…insulating film; 41…first terminal electrode; 41a…first electrode portion; 41b…second electrode portion; 41s…position of the first terminal electrode; 42s…position of the second terminal electrode; 43s…position of the third terminal electrode; 44s…Position of the fourth terminal electrode; 45…Position in the first intermediate direction; 46…Position in the second intermediate direction; 47…Bevel; 48…Ag layer; 49…Cu layer; 50…Ni layer; 51…Sn layer; 52…Flat portion; 53…Connecting portion; 54…Mounting portion; R1…Removed portion; R2…Degraded portion; AX…Axial direction; WD…Diameter of the wire; SD…Depth dimension of the bevel; EH…Height dimension of the second electrode portion; θ…Angle formed by the bevel; WL…Dimension of the connecting portion; FT…Thickness dimension of the flange portion. Detailed Implementation

[0035] Reference Figures 1-3 The coil component 21 of the first embodiment of the present invention will be described.

[0036] Main reference Figure 2The coil component 21 includes a drum-shaped core 25, which has a winding core portion 22 and a first flange portion 23 and a second flange portion 24 respectively disposed at a first end portion and a second end portion in opposite directions along the axial direction AX of the winding core portion 22. The core 25 is made of, for example, ferrite, alumina, or resin containing metallic magnetic powder. The cross-sectional shape of the winding core portion 22 is shown in the figure as, for example, a quadrilateral shape, but it can also be a polygonal shape such as a hexagon, a circular shape, an elliptical shape, or a combination thereof.

[0037] The first flange portion 23 and the second flange portion 24 each have: inner end faces 27 and 28 facing the core portion 22 and for each of the first end and the second end of the core portion 22 to be disposed; outer end faces 29 and 30 facing the outer side opposite to the inner end faces 27 and 28 respectively; mounting surfaces 31 and 32 connecting each of the inner end faces 27 and 28 to each of the outer end faces 29 and 30, and facing the mounting substrate side during installation; and top surfaces 33 and 34 located opposite to the mounting surfaces 31 and 32 respectively.

[0038] The coil component 21, for example, constitutes a common-mode choke coil, having a first wire and a second wire wound on a core portion 22 of the core 25. Figure 1 and Figure 3 Only the first wire 39 is shown in the diagram, and only one end of the first wire 39 is shown. Although the diagram is omitted, it is well known in common-mode choke coils that the first wire and the second wire are wound around the core 22 in the same direction.

[0039] One end and the other end of the first wire are electrically and mechanically connected to the first terminal electrode and the second terminal electrode, respectively. One end and the other end of the second wire are electrically and mechanically connected to the third terminal electrode and the fourth terminal electrode, respectively. Figure 1 and Figure 3 Only the first terminal electrode 41 of these first to fourth terminal electrodes is illustrated. Furthermore, in Figure 1 and Figure 3 The diagram shows a state in which one end of the first wire 39 is electrically and mechanically connected to the first terminal electrode 41.

[0040] exist Figure 2In the diagram, the position of the first terminal electrode 41 is represented by "41s" and its lead line, instead of the first terminal electrode 41 shown in the figure. Similarly, the positions of the second terminal electrodes 42 to the fourth terminal electrodes 44 are represented by "42s", "43s", and "44s" and their respective lead lines, instead of the second terminal electrodes 42 shown in the figure. When the direction orthogonal to the axial direction AX of the core portion 22, i.e., the extension direction of the mounting surfaces 31 and 32, is taken as the width direction, it can be seen from the positions represented by "41s", "42s", "43s", and "44s" that the first terminal electrode 41 and the third terminal electrode 43 are arranged along the width direction on the first flange portion 23, and the second terminal electrode 42 and the fourth terminal electrode 44 are arranged along the width direction on the second flange portion 24.

[0041] from Figure 2 It can be seen that the first flange portion 23 and the second flange portion 24 are symmetrical in shape. Furthermore, both the first flange portion 23 and the second flange portion 24 are symmetrical about their central axes. Therefore, as follows, referring to... Figure 1 and Figure 3 The portion of the first flange 23 in which the first terminal electrode 41 is provided will be described in detail, while the portions of the first flange 23 in which the third terminal electrode 43 is provided, and the portions of the second flange 24 in which the second terminal electrode 42 and the fourth terminal electrode 44 are provided respectively, will be omitted in detail. Furthermore, in the following description, "first flange" will sometimes be abbreviated as "flange," "first wire" as "wire," and "first terminal electrode" as "terminal electrode."

[0042] A bevel 47 is provided at the boundary between the mounting surface 31 and the inner end face 27 in the flange portion 23. The bevel 47 is used to connect the first intermediate position 45 located between the inner end face 27 and the outer end face 29 and in the direction along the mounting surface 31, and the position located between the mounting surface 31 and the top surface 33 (see reference). Figure 2 It extends between and in a manner connected at a second intermediate position 46 along the direction of the inner end face 27.

[0043] On the other hand, the terminal electrode 41 has a first electrode portion 41a disposed along the mounting surface 31, and a second electrode portion 41b disposed along the inclined surface 47, extending from the first electrode portion 41a to the inclined surface 47. The terminal electrode 41, for example, includes an Ag layer 48 formed by impregnating or printing a conductive paste with Ag as the conductive component, followed by sintering, and a Cu layer 49, a Ni layer 50, and a Sn layer 51 sequentially formed thereon by plating. Furthermore, in Figure 1 In (B), the thickness of the terminal electrode 41 is exaggerated in order to clearly illustrate each of the Ag layer 48, Cu layer 49, Ni layer 50 and Sn layer 51.

[0044] The wire 39 may have, for example, a center wire 39a made of a metal with good conductivity such as copper, silver or gold, and an insulating film 39b covering the center wire 39a, made of an electrically insulating resin such as polyamide-imide, polyurethane or polyester-imide.

[0045] To connect the wire 39 to the terminal electrode 41, a thermoforming process is used to press the end of the wire 39 toward the terminal electrode 41 using a heating element. As a result, the wire 39 is electrically and mechanically connected to both the first electrode portion 41a and the second electrode portion 41b. This improves the reliability of the connection between the terminal electrode 41 and the wire 39. Furthermore, since the second electrode portion 41b is provided along the inclined surface 47, stress concentration on the wire 39 near the ridge line where the mounting surface 31 of the flange portion 23 intersects with the inner end face 27 can be mitigated during thermoforming, making wire breakage less likely in that area.

[0046] Through hot pressing, the insulating coating 39b of the wire 39 is decomposed and removed by heat. Figure 1 In this context, the removed portion is indicated by "R1". Furthermore, the insulating film 39b, located near the removed portion R1, will deteriorate even if it is not removed by thermoforming. Figure 1 In the text, the deterioration of the insulating coating 39b caused by hot-press bonding is indicated by "R2".

[0047] exist Figure 1 When the wire 39 is connected to the terminal electrode 41, the diameter of the wire 39 on the core portion 22, i.e., the original diameter WD of the wire 39 before heat-pressing, is larger than the height dimension EH of the second electrode portion 41b measured in a direction orthogonal to the mounting surface 31. The depth dimension SD of the distance from the first intermediate position 45 to the second intermediate position 46, i.e., the inclined surface 47, measured in a direction orthogonal to the mounting surface 31, is larger than the diameter WD of the wire 39. The diameter WD of the wire 39 is 100 μm or more, for example, 150 μm. In the coil component according to the present invention, it is more advantageous for the wire to have a diameter of 100 μm or more and be relatively thick.

[0048] By satisfying the above conditions, a portion of the wire 39 located on the inclined surface 47 can be left unpressed during hot-press bonding. Therefore, the removed portion R1 of the insulating film 39b in the wire 39 can be reduced, and the diameter of the wire 39 near the removed portion R1 of the insulating film 39b can be ensured. As a result, wire breaks near the removed portion R1 of the insulating film 39b are less likely to occur.

[0049] Furthermore, the wire 39 connected to the terminal electrode 41 is not only electrically and mechanically connected to the first electrode portion 41a, but also electrically and mechanically connected to the second electrode portion 41b disposed along the inclined surface 47, thus enabling the wire 39 to be positioned along the inclined surface 47. Therefore, the degree to which the deteriorated portion R2 of the insulating film 39b of the wire 39, which may be caused by thermoforming, protrudes away from the inner end face 27 of the flange portion 23 can be reduced. As a result, even if a deteriorated portion R2 is generated in the insulating film 39b during thermoforming, the reliability, for example, that can prevent electrical short circuits between multiple wires in a common-mode choke coil can be improved. Furthermore, it is preferable that the deteriorated portion R2 is completely contained at a position on the outer end face 29 side of the surface containing the inner end face 27 of the flange portion 23.

[0050] Furthermore, since the second electrode portion 41b in the terminal electrode 41 only extends to the midway of the inclined surface 47, i.e., there is a portion without an electrode formed on the side of position 46 on the second midway of the inclined surface 47, the wire 39 connected to the terminal electrode 41 is in a state separated from the inclined surface 47. During thermoforming, the insulating film 39b will not collide with the core 25 and deform, thus maintaining its original shape. Therefore, the resistance to corrosion of the wire 39 caused by flux and moisture is improved.

[0051] This embodiment also has the following preferred features.

[0052] Preferably, when viewed from a direction orthogonal to the mounting surface 31 of the flange portion 23, that is, when viewed from... Figure 1 When viewed in the direction shown in (A), the contour lines of the inclined surface 47 extend in a direction orthogonal to the axial direction AX relative to the core portion 22. According to this structure, when the wire 39 is pressed onto the terminal electrode 41 in a state arranged along the inclined surface 47, the end of the wire 39 can be located on the outer end face 29 side of the flange portion 23, so it is easy to cut off the excess portion of the wire 39.

[0053] Based on the above structure, the angle θ formed by the inclined plane 47 relative to the plane containing the mounting surface 31 (refer to...) Figure 1 (B) The angle θ is preferably 20° or more and 60° or less. If the angle θ is less than 20°, the wire 39 will be subjected to large tensile stress due to the pressing of the heating element during hot pressing, which may cause the wire 39 to break. On the other hand, if the angle θ exceeds 60°, the core 25 will be difficult to form.

[0054] Preferably, a flat portion 52 extending parallel to the mounting surface 31 is provided at a second intermediate position 46 where one end of the inclined surface 47 is positioned. This structure facilitates the molding of the core 25 in the mold. Furthermore, in Figure 2 The illustration of the flat portion 52 is omitted.

[0055] Regarding the dimensions measured along the axial direction AX of the core portion 22, the dimension WL of the connection portion where the wire 39 connects to the first electrode portion 41a of the terminal electrode 41 (refer to...) Figure 1 (B) Preferably, it is the dimension between the inner end face 27 and the outer end face 29 of the flange portion 23, that is, the thickness direction dimension FT of the flange portion 23 (refer to...). Figure 1 (B)) is more than 20% and less than 50%. If it is less than 20%, the tensile strength of the wire 39 will be lower, and the current density flowing through the terminal electrode 41 will be higher (the current value per unit will be lower), which may lead to electromigration or wire breakage during long-term reliability testing. On the other hand, if it exceeds 50%, the deteriorated portion R2 of the insulation coating 39b may protrude significantly from the inner end face 27 of the flange portion 23.

[0056] The preferred terminal electrode 41 has a first electrode portion 41a that connects to the wire 39 and a mounting portion 54 that connects to the mounting substrate. The connecting portion 53 and the mounting portion 54 are coplanar. The connecting portion 53 is also the crimping portion where the wire 39 is crimped to the first electrode portion 41a. The mounting portion 54 is the portion that faces the pads formed on the mounting substrate when the coil component 21 is mounted on the mounting substrate. According to the above structure, when the wire 39 is crimped to the connecting portion 53, it is easy to cut off the excess portion of the wire 39. Without the above structure, more specifically, when the height of the connecting portion 53 is lower than the height of the mounting portion 54, there is a possibility that the wire 39 cannot be sufficiently flattened during thermoforming. In this case, the excess portion of the wire 39 is not cut off and is likely to remain. Therefore, in the process of cutting the wire 39, it is necessary not only to tear off the wire 39 but also to use a cutting tool.

[0057] As described above, the terminal electrode 41 includes an Ag layer 48 as a substrate and a Cu layer 49, a Ni layer 50, and a Sn layer 51 sequentially formed thereon by plating. That is, the terminal electrode 41 has a Sn layer 51 on its surface, but in this case, as... Figure 1 As shown in (B), preferably a portion of the Sn layer 51 is located in at least a portion of the terminal electrode 41 that is in contact with the wire 39. The Sn layer 51 not only provides good solderability to the terminal electrode 41 during installation, but also, when the center wire 39a of the wire 39 is made of copper, forms a Cu-Sn alloy layer between the Sn layer 51 and the center wire 39a, thereby improving the bonding strength between the terminal electrode 41 and the wire 39.

[0058] In particular, if the Sn layer 51 is located in the portion of the second electrode portion 41b along the inclined surface 47 that is connected to the wire 39, the bonding strength between the wire 39 and the terminal electrode 41 at the inclined surface 47 can be improved.

[0059] As described above, when the Sn layer 51 is located in the portion of the second electrode portion 41b along the inclined plane 47 that is in contact with the wire 39, such as Figure 1 As shown in (B), the Sn layer 51 preferably becomes thicker as it moves from the first intermediate position 45 towards the second intermediate position 46. By making the Sn layer 51 thicker, the Cu-Sn alloy layer can be increased, further improving the bonding strength between the terminal electrode 41 and the wire 39. The Cu-Sn alloy layer becomes thicker as the thickness of the Sn layer 51 increases. Higher bonding strength is obtained in the thicker portions of the Cu-Sn alloy layer.

[0060] In addition, Figure 1 In (B), the figure shows the Sn layer 51 present in the portion of the first electrode portion 41a that is connected to the wire 39, but sometimes the Sn layer is completely or almost absent in this portion.

[0061] In addition, in the first embodiment, such as Figure 2 As shown, in each of the first flange portion 23 and the second flange portion 24, two inclined surfaces 47 are respectively located at both ends of the flange portions 23 and 24 in the width direction. According to this structure, the wire can be easily wound along the inclined surfaces 47, thus making it easy to cut off excess wire. Furthermore, when it is desired to cut off excess wire with a cutter, the excess wire can be positioned at the outermost edge of the core 25 within the device, thus also having the advantage of making it easy for the cutter to contact the excess wire.

[0062] In the first embodiment, as described above, regarding Figure 1 and Figure 3 The portion of the first flange 23 in which the first terminal electrode 41 is provided has been described, but the portion of the first flange 23 in which the third terminal electrode 43 is provided, and the portion of the second flange 24 in which the second terminal electrode 42 and the fourth terminal electrode 44 are respectively provided, also have substantially the same structure.

[0063] The dimensions of the coil component 21 are arbitrary. As an example, the length (axial direction AX) dimension is 2.0 mm, the width dimension is 1.2 mm, and the height dimension is 1.6 mm.

[0064] The coil component 21 is preferably manufactured as follows, for example.

[0065] First, core 25 is prepared. To manufacture core 25, ferrite powder is stamped using a mold, and the resulting molded body is fired to obtain a sintered body that should become core 25. Then, burrs are removed by tumbling the sintered body that becomes core 25 to obtain core 25. Although in Figures 1 to 3 The illustration is omitted, but the edges of core 25 are chamfered and have small rounded corners.

[0066] Next, in order to provide terminal electrodes 41 to 44 on the core 25, a conductive paste containing Ag is applied to the mounting surfaces 31 and 32 of the first flange portion 23 and the second flange portion 24, and sintering is performed to form an Ag layer 48. Then, an electrolytic barrel plating method is used to sequentially form a Cu layer 49, a Ni layer 50 and a Sn layer 51.

[0067] Next, for example, the wire is wound onto the core portion 22 of the core 25 through a nozzle, and one end of the first wire 39 is connected to the first terminal electrode 41 and the second terminal electrode, respectively. One end of the second wire is connected to the third terminal electrode and the fourth terminal electrode, respectively. Here, the connection between the wire and the terminal electrodes is achieved, for example, by thermoforming using a heating element. Any excess portion of the wire connected to the terminal electrodes is cut off and removed as needed using a cutter.

[0068] As described above, complete coil component 21.

[0069] Figures 4 to 8 These are perspective views showing the overall appearance of the core of the coil component according to the second to sixth embodiments of the present invention with the mounting surface facing upwards. Figures 4 to 8 Is with Figure 2 The corresponding diagram. In Figures 4 to 8 In the middle, to and Figure 2 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.

[0070] exist Figure 4 In the core 25a shown, when the direction orthogonal to the axial direction AX of the winding core portion 22, i.e., the extending direction of the mounting surfaces 31 and 32, is taken as the width direction, the inclined surface 47 at the position 43s where the third terminal electrode is provided in the first flange portion 23 is located near the center in the width direction of the first flange portion 23. Similarly, the inclined surface 47 at the position 42s where the second terminal electrode is provided in the second flange portion 24 is located near the center in the width direction of the second flange portion 24. With this core 25a, the wire can be wound to the terminal electrodes 41 to 44 with the shortest possible distance.

[0071] exist Figure 5In the core 25b shown, when the direction orthogonal to the axial direction AX of the core portion 22, i.e., the extension direction of the mounting surfaces 31 and 32, is taken as the width direction, the inclined surface 47 at position 41s where the first terminal electrode is provided and the inclined surface 47 at position 43s where the third terminal electrode is provided in the first flange portion 23 are both located near the center in the width direction of the first flange portion 23. Similarly, the inclined surface 47 at position 42s where the second terminal electrode is provided and the inclined surface 47 at position 44s where the fourth terminal electrode is provided in the second flange portion 24 are both located near the center in the width direction of the second flange portion 24. With such a core 25b, molding using a mold is easy. In addition, since the protrusion in the mold that supports the molding of the inclined surface 47 is located near the center in the width direction, stress is less likely to concentrate on this protrusion, thus improving the durability of the mold.

[0072] Figure 6 The core 25c shown is a core for a coil component having one wire, with a bevel 47 provided at the center of the width direction of each of the first flange portion 23 and the second flange portion 24. According to this core 25c, since it has a structure that is symmetrical about the portion of the first flange portion 23 and the second flange portion 24 that crimps the wire, the coil component has good mounting properties.

[0073] Figure 7 The core 25d shown is Figure 6 The core 25c shown is also a core for a coil component having a single wire. Inclined surfaces 47 are provided at the ends of the first flange 23 and the second flange 24 in the width direction, and the inclined surfaces 47 on the first flange 23 and the second flange 24 are arranged opposite each other in the diagonal direction. With this core 25d, the winding of the wire is simple.

[0074] Figure 8 The core 25e shown is a core for a coil component with three wires, such as a three-phase common-mode choke coil. Three bevels 47 are arranged along the width direction in each of the first flange portion 23 and the second flange portion 24.

[0075] As Figure 8 The modified example of the core 25e shown can also be a core for a coil component having four or more wires, wherein four or more inclined surfaces are arranged along the width direction in each of the first flange portion and the second flange portion.

[0076] The present invention has been described above in connection with the illustrated embodiments, but various other embodiments are possible within the scope of the present invention.

[0077] For example, although not shown, the top plate can also be configured to connect the top surfaces of the first flange and the second flange of the core. When both the core and the top plate are made of magnetic materials, the core and the top plate form a closed magnetic circuit.

[0078] Furthermore, the scope of the present invention is not limited to the above-described embodiments, but also includes embodiments in which structures are partially replaced or combined between different embodiments.

Claims

1. A coil component, wherein, have: The core has a winding core portion and flange portions disposed at both ends of the winding core portion in the axial direction; The wire is wound around the core portion; and Terminal electrodes are disposed on the flange portion for electrical and mechanical connection of the ends of the wire. The flange portion has: The inner end face faces the core portion and is provided for the end of the core portion in the axial direction; The outer end face faces the opposite side of the inner end face; The mounting surface connects the inner end face to the outer end face and faces the mounting substrate side during installation. as well as The top surface, facing the opposite side of the mounting surface. A bevel is provided at the boundary between the mounting surface and the inner end face. The bevel extends in such a way that it connects a first intermediate position located between the inner end face and the outer end face in the direction along the mounting surface, and a second intermediate position located between the mounting surface and the top surface in the direction along the inner end face. The terminal electrode has a first electrode portion disposed along the mounting surface and a second electrode portion disposed along the inclined surface, extending from the first electrode portion to the inclined surface. The wire is electrically and mechanically connected at both the first electrode portion and the second electrode portion. The diameter of the wire on the core portion is larger than the height dimension of the second electrode portion measured in a direction orthogonal to the mounting surface, and the depth dimension of the inclined plane, measured in a direction orthogonal to the mounting surface, from the first intermediate position to the second intermediate position, is larger than the diameter of the wire.

2. The coil component according to claim 1, wherein, When viewed from a direction orthogonal to the mounting surface, the contour lines of the slope extend in a direction orthogonal to the axial direction of the core portion.

3. The coil component according to claim 2, wherein, The angle between the inclined plane and the plane containing the mounting surface is greater than 20° and less than 60°.

4. The coil component according to any one of claims 1 to 3, wherein, A flat portion extending parallel to the mounting surface is provided at a second intermediate position where one end of the inclined surface is positioned.

5. The coil component according to any one of claims 1 to 3, wherein, When the direction orthogonal to the axial direction of the core portion and the extending direction of the mounting surface are taken as the width direction, The two terminal electrodes and the two inclined surfaces are respectively arranged along the width direction on each of the flange portions.

6. The coil component according to claim 5, wherein, The two inclined surfaces are located at the two ends of the width direction of each flange.

7. The coil component according to claim 5, wherein, The two inclined surfaces are located near the center in the width direction of each of the flanges.

8. The coil component according to any one of claims 1 to 3, wherein, For dimensions measured in the axial direction of the core portion, the dimension of the connection portion connecting the wire to the first electrode portion of the terminal electrode is 20% or more and 50% or less of the dimension between the inner end face and the outer end face of the flange portion.

9. The coil component according to any one of claims 1 to 3, wherein, The first electrode portion of the terminal electrode has a connecting portion for connecting the wire and a mounting portion for connecting to a mounting substrate, wherein the connecting portion and the mounting portion are coplanar.

10. The coil component according to any one of claims 1 to 3, wherein, The wire has a linear central conductor and an insulating film covering the central conductor. The insulating film has a portion that has deteriorated due to heat. The deteriorated portion is completely contained in a position closer to the outer end face than the surface containing the inner end face.

11. The coil component according to any one of claims 1 to 3, wherein, The terminal electrode has a Sn layer on its surface, a portion of which is located in at least a portion of the terminal electrode that is in contact with the wire.

12. The coil component according to claim 11, wherein, The Sn layer includes a portion located in the second electrode portion that is in contact with the wire.

13. The coil component according to claim 12, wherein, The Sn layer in the portion of the second electrode that is in contact with the wire becomes thicker as it moves from the first intermediate position toward the second intermediate position.

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