Coil member and method for manufacturing coil member

Abstract

The coil component of the present application includes an outer body, a coil, and a pair of terminal electrodes. The coil is disposed in the outer body. The pair of terminal electrodes are electrically connected to the coil and disposed on the outer body. The outer body has a first portion that covers the coil and is made of resin, and a second portion that includes a side on which the pair of terminal electrodes are disposed. The second portion includes a material having a relative dielectric constant lower than that of the resin and is disposed between the coil and the pair of terminal electrodes.

Description

Technical Field

[0001] This disclosure relates to a coil component and a method for manufacturing the coil component. Background Technology

[0002] Known coil components include: a coil made of winding wire, a core on which the winding wire is wound, a resin component covering the coil and the core substantially as a whole, and terminal electrodes electrically connected to the coil and disposed on the side of the resin component (for example, see Japanese Patent Application Publication No. 2015-70154). Summary of the Invention

[0003] In the aforementioned existing coil components, stray capacitance is generated due to the relative position of the coil and terminal electrodes. This stray capacitance can affect the characteristics of the coil components. For example, stray capacitance leads to a decrease in the self-resonant frequency in the coil components. Therefore, a technique to suppress the decrease in self-resonant frequency is desired.

[0004] One aspect of the present invention aims to provide a coil component that suppresses the decrease in self-resonant frequency. Another aspect of the present invention aims to provide a method for manufacturing a coil component that suppresses the decrease in self-resonant frequency.

[0005] One embodiment of the present invention includes a coil component comprising: an outer casing, a coil, and a pair of terminal electrodes. The coil is disposed within the outer casing. The pair of terminal electrodes are electrically connected to the coil and are disposed on the outer casing. The outer casing comprises: a first portion covering the coil and made of resin, and a second portion having the pair of terminal electrodes disposed thereon. The second portion comprises a material having a relative permittivity lower than that of the resin and is disposed between the coil and the pair of terminal electrodes.

[0006] In this coil component, a second portion is disposed between the coil and the terminal electrodes. This second portion comprises a low-dielectric-constant material having a lower relative dielectric constant than that of the resin in the first portion. Therefore, the stray capacitance generated between the coil and the terminal electrodes is reduced by the low-dielectric-constant material of the second portion, and the decrease in the self-resonant frequency in the coil component is suppressed.

[0007] In one of the above embodiments, the coil may also include a winding. The winding may also have a helical first winding portion and a pair of second winding portions. Each of the pair of second winding portions may also be continuous with a corresponding terminal electrode in a pair of terminal electrodes. Each terminal electrode may also have a flat plate shape.

[0008] For example, the electrical connection between the terminal electrodes and the coil may be severed if a physical impact is applied to the coil components. In a structure where the terminal electrodes and the second winding portion of the winding are continuous, the electrical connection between the terminal electrodes and the coil is difficult to sever even if a physical impact is applied to the coil components.

[0009] The flat plate structure of each terminal electrode facilitates the electrical connection between the terminal electrode and other electronic components when the coil component is mounted on them.

[0010] In one of the above embodiments, the second part may also include a flat side surface disposed on a pair of terminal electrodes. Each second winding portion may also have: an inner portion disposed within the outer casing, and an outer portion disposed on the outer casing and continuous with the corresponding terminal electrode. Alternatively, the inner portion may extend in a direction intersecting the side surface, and the outer portion may extend in a direction along the side surface.

[0011] In this case, the coil covered by the outer casing and the terminal electrodes disposed on the outer casing are more reliably connected through the second winding portion.

[0012] In one of the above methods, the winding may also have: a conductor and a covering layer that covers the conductor and has electrical insulation properties.

[0013] In this case, because the wire is protected by the sheath, it is difficult to damage even when the wire is bent.

[0014] In one of the above embodiments, the coil component may further include a core disposed inside the coil. The core may also be made of resin.

[0015] Another method for manufacturing a coil component includes: a step of preparing a coil, a step of forming an outer casing to cover the coil, and a step of configuring a pair of terminal electrodes electrically connected to the coil on the outer casing. The step of forming the outer casing includes: a step of forming a first portion of resin to cover the coil, and a step of forming a predetermined second portion of a specified material to configure the pair of terminal electrodes. In the step of configuring the pair of terminal electrodes, the pair of terminal electrodes are configured on the outer casing such that the second portion is positioned between the coil and the pair of terminal electrodes. The specified material has a relative permittivity lower than that of the resin.

[0016] In another embodiment described above, a second portion is formed between the coil and the terminal electrodes using a low-dielectric-constant material with a lower relative dielectric constant than the resin of the first portion. Therefore, the stray capacitance generated between the coil and the terminal electrodes is reduced by the low-dielectric-constant material of the second portion, and the decrease in the self-resonant frequency in the coil component is suppressed.

[0017] In another method described above, the coil preparation process may also include preparing a coil made of winding wire. The method for manufacturing the coil component may further include, before the process of configuring a pair of terminal electrodes, a process of forming a pair of terminal electrodes continuous with the winding wire by pressing the two ends of the winding wire.

[0018] In this case, the process of connecting the terminal electrodes to the coil is not required in the manufacturing process of the coil component. Therefore, the manufacturing process of the coil component is simplified.

[0019] By ensuring continuity between the winding and the terminal electrodes, the electrical connection between the terminal electrodes and the coil is difficult to break even when a physical impact is applied to the coil components.

[0020] The invention will be more fully understood based on the detailed description and accompanying drawings given below, which are given by way of illustration only and should not be considered as limiting the invention.

[0021] Further applicability of the invention will become apparent from the detailed description given below. However, based on the detailed description, various changes and modifications within the spirit and scope of the invention will be apparent to those skilled in the art. Therefore, it should be understood that while the detailed description and specific examples indicate embodiments of the invention, they are given by way of illustration only. Attached Figure Description

[0022] Figure 1 This is a perspective view showing the coil component of the first embodiment.

[0023] Figure 2 This is a perspective view of the coil component of the first embodiment, shown from the side of the second part where the terminal electrodes are arranged.

[0024] Figure 3 This is a diagram showing the cross-sectional structure of the winding connection and terminal electrodes.

[0025] Figure 4 This is an enlarged view of the connection part of the winding and the terminal electrodes.

[0026] Figure 5 This is a flowchart illustrating the manufacturing process of the coil component according to the first embodiment.

[0027] Figure 6 This is a diagram illustrating the manufacturing process of the coil component according to the first embodiment.

[0028] Figure 7 This is a diagram illustrating the manufacturing process of the coil component according to the first embodiment.

[0029] Figure 8 This is a diagram illustrating the manufacturing process of the coil component according to the first embodiment.

[0030] Figure 9 This is a diagram illustrating the manufacturing process of the coil component according to the first embodiment.

[0031] Figure 10 This is a diagram illustrating the manufacturing process of the coil component according to the first embodiment.

[0032] Figure 11 This is a diagram illustrating the manufacturing process of the coil component according to the first embodiment.

[0033] Figure 12 This is a diagram showing the frequency characteristics of the coil components.

[0034] Figure 13 This is a perspective view showing the coil component according to the second embodiment.

[0035] Figure 14 This is a flowchart illustrating the manufacturing process of the coil component according to the second embodiment.

[0036] Figure 15 This is a diagram illustrating the manufacturing process of the coil component according to the second embodiment.

[0037] Figure 16 This is a diagram illustrating the manufacturing process of the coil component according to the second embodiment. Detailed Implementation

[0038] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals are used to refer to the same elements or elements having the same function, and repeated descriptions are omitted.

[0039] <First Implementation>

[0040] Reference Figures 1-3 The structure of the coil component 1 in the first embodiment will be described. Figure 1 This is a perspective view showing the coil component 1 of this embodiment. Figure 2 This is a perspective view of the coil component 1 of this embodiment, shown from the side 74 of the second part 70 on which the terminal electrodes 20 and 30 are arranged. Figure 3 This is a cross-sectional view showing the connection portion 13 of the winding 11 and the terminal electrode 20. The coil component 1 includes: a coil 10, a pair of terminal electrodes 20 and 30, a core 40, and an outer casing 50.

[0041] The coil 10 is composed of a winding 11. The winding 11 has a helical portion 12. Hereinafter, the portion 12 of the winding 11 will be referred to as the coil portion 12. The coil portion 12 is disposed outside the core 40. In the following description, the axial direction of the coil 10 is defined as direction X, the direction intersecting direction X is defined as direction Y, and the direction intersecting both direction X and direction Y is defined as direction Z. In this embodiment, direction X, direction Y, and direction Z are orthogonal to each other.

[0042] The winding 11 has a pair of connecting portions 13 and 14. The pair of connecting portions 13 and 14 are continuous with both ends of the coil portion 12 and electrically connect the coil 10 and a pair of terminal electrodes 20 and 30. For example, when the coil portion 12 constitutes the first winding portion, each connecting portion 13 and 14 constitutes the second winding portion.

[0043] The coil portion 12 has multiple turns A. That is, the coil 10 has multiple turns A. The multiple turns A are arranged along the direction X. When viewed from the direction X, the area defined by each turn A has a rectangular shape with rounded corners. The shape of each turn A can also be annular. Turns A1 and A2, which are located at both ends in the direction X, are connected to terminal electrodes 20 and 30 respectively via connecting portions 13 and 14.

[0044] like Figure 3 As shown, the winding 11 includes a conductor 11a and a sheathing layer 11b covering the conductor 11a. The conductor 11a may also be made of a conductive metallic material. The metallic material contains copper, silver, nickel, or chromium. The sheathing layer 11b may also be made of an electrically insulating material. The electrically insulating material includes polyurethane. Alternatively, a portion of the sheathing layer 11b may be removed at the connecting portions 13 and 14 in the winding 11 to expose the conductor 11a.

[0045] like Figure 2 As shown, a pair of terminal electrodes 20 and 30 are disposed on the side 74 of the second portion 70 of the outer casing 50, which will be described later. Specifically, the pair of terminal electrodes 20 and 30 are disposed at their respective ends in the Y direction of the side 74 in a separated manner. Each terminal electrode 20 and 30 may also be made of a conductive metallic material. The metallic material may contain copper, silver, nickel, or chromium. Each terminal electrode 20 and 30 may also be made of the same material as the wire 11a of the winding 11.

[0046] Each terminal electrode 20, 30 has a flat plate shape. In a top view along direction Z, each terminal electrode 20, 30 has a generally rectangular shape. Each terminal electrode 20, 30 is arranged on the side 74 with its long side along direction X. Each terminal electrode 20, 30 has a base end portion 21, 31 and a front end portion 22, 32. The base end portions 21, 31 of the terminal electrodes 20, 30 are respectively connected to the connecting portions 13, 14 of the winding 11.

[0047] Each terminal electrode 20, 30 is opposite to the coil 10. In this embodiment, the two ends of each terminal electrode 20, 30 in the Y direction are opposite to the coil 10 in the Z direction. Alternatively, the entire terminal electrode 20, 30 may not be opposite to the coil 10, but at least a portion of each terminal electrode 20, 30 may be opposite to the coil 10.

[0048] The core 40 has a generally cuboid shape and is arranged with its short side along the X direction. A coil portion 12 for winding the wire 11 is arranged on the outer side of the core 40. The core 40 may be made of resin, ferrite, or alumina. The core 40 may also be made of the same or different resin as the first part 60 of the outer casing 50 described later. The shape of the core 40 is not limited; for example, it may be cylindrical. A pair of flanges may be formed at both ends of the core 40 in the X direction. The pair of flanges may extend from the core 40 along the Y and Z directions and be formed as walls facing each other in the X direction. The pair of flanges may also restrict movement of the coil 10 in the X direction.

[0049] The outer casing 50 has a cuboid shape. The outer casing 50 may also have a cuboid shape with chamfered corners and edges, or a cuboid shape with rounded corners and edges. The width of the outer casing 50 along the X direction may be 0.2 mm, and the width along the Y direction may be 0.4 mm. The outer casing 50 has a first portion 60 and a second portion 70 arranged in an overlapping manner along the Z direction.

[0050] The first part 60 has a cuboid shape and covers the coil 10 and the core 40. The first part 60 is made of resin. The resin constituting the first part 60 can also be a liquid crystal polymer, polyimide resin, crystalline polystyrene, epoxy resin, or fluoropolymer. The polyimide resin can also be bismaleimide resin. The fluoropolymer can also be polytetrafluoroethylene resin (PTFE). The relative permittivity of the resin constituting the first part 60 can also be 2 or more and 4 or less. The resin constituting the first part 60 can also contain fillers or impurities to improve the properties of the coil component 1.

[0051] The first part 60 has a pair of end faces 61 and 62 and four side faces 63, 64, 65, and 66. The pair of end faces 61 and 62 are opposite each other in the Y direction. Each end face 61 and 62 is a flat surface extending along the X and Z directions. The four side faces 63, 64, 65, and 66 connect the pair of end faces 61 and 62 to each other. Side faces 63 and 64 are opposite each other in the Z direction. Side faces 63 and 64 are flat surfaces extending along the X and Y directions. Side faces 63 and 64 have a rectangular shape defined by a pair of short sides along the X direction and a pair of long sides along the Y direction. Side face 64 contacts side face 73 of the second part 70, which will be described later. Side faces 65 and 66 are opposite each other in the X direction. Side faces 65 and 66 are flat surfaces extending along the Y and Z directions.

[0052] The thickness T1 of the first portion 60 in the Z direction can also be between 180 μm and 320 μm. The thickness T1 of the first portion 60 is the width between the side surface 63 and the side surface 64. In this embodiment, the first portion 60 covers the entire coil 10 and the core 40. The first portion 60 may not necessarily cover the entire coil 10 and the core 40; a portion of the coil 10 or a portion of the core 40 may be exposed outside the first portion 60.

[0053] The second part 70 has a cuboid shape and is disposed between the coil 10 and a pair of terminal electrodes 20, 30. The second part 70 includes a low-dielectric-constant material having a relative permittivity lower than that of the resin constituting the first part 60. The low-dielectric-constant material includes a material having a relative permittivity lower than that of the resin constituting the first part 60. In this embodiment, the entire second part 70 is composed of a low-dielectric-constant material. The entire second part 70 may also not be composed of a low-dielectric-constant material. The second part 70 may, for example, be constructed by laminating a layer composed of a low-dielectric-constant material and a layer composed of a material other than the low-dielectric-constant material in the Z direction. The low-dielectric-constant material included in the second part 70 may also be a liquid crystal polymer, polyimide resin, crystalline polystyrene, epoxy resin, or fluoropolymer. The polyimide resin may also be a bismaleimide resin. The fluoropolymer may also be polytetrafluoroethylene (PTFE) resin. The relative permittivity of the low-dielectric-constant material may, for example, be 2 or higher and 3 or lower. In addition to low dielectric constant materials, part 70 may also contain fillers or impurities for improving the characteristics of coil component 1.

[0054] The second part 70 has a pair of end faces 71 and 72 and four side faces 73, 74, 75, and 76. The pair of end faces 71 and 72 are opposite each other in the Y direction. Each end face 71 and 72 is a flat surface extending along the X and Z directions. The four side faces 73, 74, 75, and 76 connect the pair of end faces 71 and 72 to each other. Side faces 73 and 74 are opposite each other in the Z direction. Side faces 73 and 74 are flat surfaces extending along the X and Y directions. Side faces 73 and 74 have a rectangular shape defined by a pair of short sides along the X direction and a pair of long sides along the Y direction. Side face 73 contacts side face 64 of the first part 60. Side faces 75 and 76 are opposite each other in the X direction. Side faces 75 and 76 are flat surfaces extending along the Y and Z directions.

[0055] The thickness T2 of the second portion 70 in direction Z can be between 5 μm and 20 μm, or between 10 μm and 15 μm. The thickness T2 of the second portion 70 is the width between side 73 and side 74. For example, the thickness T2 of the second portion 70 can also be more than one-twentieth and less than one-tenth of the thickness T1 of the first portion 60.

[0056] The outer edge shape of the side surface 73 of the second part 70 is consistent with the outer edge shape of the side surface 64 of the first part 60. Therefore, the end faces 61 and 62 of the first part 60 and the end faces 71 and 72 of the second part 70 are respectively on the same plane. The side surfaces 65 and 66 of the first part 60 and the side surfaces 75 and 76 of the second part 70 are respectively on the same plane.

[0057] In this embodiment, the second portion 70 is disposed over the entire area of ​​the side surface 64 of the first portion 60. However, the second portion 70 may not necessarily be disposed over the entire area of ​​the side surface 64. It is sufficient that the second portion 70 is disposed over at least a portion of the area between the coil 10 and the terminal electrodes 20, 30. For example, the second portion 70 may also be disposed only over a portion of the area between the coil 10 and the terminal electrodes 20, 30. Figure 2 The coil 10 shown is located between the front ends 22 and 32 of each terminal electrode 20 and 30.

[0058] Reference Figure 3 and Figure 4 The detailed structure of the connecting portions 13 and 14 of the winding 11 and the terminal electrodes 20 and 30 of this embodiment will be described. Figure 4 This is an enlarged view of the connecting portion 13 and the terminal electrode 20 of the winding 11. Hereinafter, the connecting portion 13 and the terminal electrode 20 will be used as examples for description, but the connecting portion 14 and the terminal electrode 30 of this embodiment have the same structure as the connecting portion 13 and the terminal electrode 20.

[0059] The connecting portion 13 of the winding 11 includes an inner portion 13a disposed within the outer casing 50 and an outer portion 13b disposed on the outer casing 50. The inner portion 13a is continuous with the coil portion 12 inside the first portion 60 of the outer casing 50. The outer portion 13b is continuous with the base end portion 21 of the terminal electrode 20 outside the outer casing 50. The connecting portion 13 is bent such that the inner portion 13a and the outer portion 13b extend in different directions. In this embodiment, the connecting portion 13 is bent such that the angle between the inner portion 13a and the outer portion 13b is approximately 90°. The inner portion 13a extends in the Z direction, intersecting the side surface 74 of the second portion 70. The outer portion 13b extends in the X direction, along the side surface 74 of the second portion 70. The terminal electrode 20, which is connected to the outer portion 13b, is also disposed such that it extends in the X direction, just like the outer portion 13b.

[0060] like Figure 3 As shown, a portion of the outer portion 13b is opposite to the coil 10 in the Z direction. As described above, the winding 11 has a conductor 11a and a covering layer 11b covering the conductor 11a. In the outer portion 13b of the winding 11, the covering layer 11b also covers the periphery of the conductor 11a. Therefore, the covering layer 11b is located between the conductor 11a and the coil 10 in the outer portion 13b. The covering layer 11b may also be made of a low dielectric constant material with a lower relative dielectric constant than the resin constituting the first portion 60. The covering layer 11b may also not cover the conductor 11a entirely in the outer portion 13b. For example, a portion of the covering layer 11b of the outer portion 13b may be removed to expose the conductor 11a.

[0061] like Figure 3 As shown, the thickness of the terminal electrode 20 in direction Z is smaller than the diameter of the outer portion 13b of the winding 11. The thickness of the terminal electrode 20 in direction Z can also be more than 10 μm and less than 20 μm. The terminal electrode 20 is fixed to the side surface 74 of the second portion 70 by adhesive 80. The terminal electrode 20 can also be arranged slightly apart from the side surface 74. The terminal electrode 20 can also be left unfixed to the side surface 74.

[0062] The connecting portion 14 and terminal electrode 30 of the winding 11 have the same structure as the connecting portion 13 and terminal electrode 20 of the winding 11 described above. For example... Figure 2 As shown, the connecting portion 14 has an inner portion 14a disposed within the outer casing 50 and an outer portion 14b disposed on the outer casing 50. The inner portion 14a and the outer portion 14b of the connecting portion 14 correspond to the inner portion 13a and the outer portion 13b of the connecting portion 13. The base end portion 31 of the terminal electrode 30 is continuous with the outer portion 14b of the connecting portion 14. The terminal electrode 30 is similarly fixed to the side surface 74 of the second portion 70 by an adhesive, just like the terminal electrode 20.

[0063] Reference Figures 5-11 An example of the manufacturing method of the coil component 1 in this embodiment will be described. Figure 5 This is a flowchart illustrating the manufacturing process of the coil component 1 in this embodiment. Figures 6 to 11 This is a diagram showing the manufacturing process of the coil component 1 in this embodiment.

[0064] First, prepare Figure 6 The coil 10 shown (step S10). In step S10, the coil 10 can also be made by spirally winding a portion of the winding 11 around the outside of the core 40, or a coil 10 that has already been made can be prepared. Figure 6The spiral portion of the winding 11 shown is the coil portion 12. The winding 11 has remaining portions 16 and 17 that are continuous with both ends of the coil portion 12. The remaining portions 16 and 17 are the portions that later become a pair of terminal electrodes 20 and 30 and connecting portions 13 and 14.

[0065] Next, it forms Figure 7 The first portion 60 of the outer casing 50 shown (step S11). Specifically, firstly, the coil 10 and the core 40 are fixed in the mold, and the material of the first portion 60, i.e., resin, which has been heated and softened, flows into the mold. After the resin constituting the first portion 60 cools and solidifies, the coil 10 and the core 40 covered by the first portion 60 are removed from the mold. The method of forming the first portion 60 is not limited to the method described above. In this embodiment, the first portion 60 is formed in a manner that covers the entire coil 10 and the core 40, but the first portion 60 may also be formed in a manner that exposes a portion of the coil 10 or a portion of the core 40.

[0066] Next, it forms Figure 8 The second portion 70 of the outer casing 50 is shown (step S12). Specifically, firstly, after the coil 10 and core 40, which will be covered by the first portion 60, are fixed in the mold, the material of the heated and softened second portion 70 is allowed to flow into the mold. In this embodiment, the material of the second portion 70 is allowed to flow in such a way that it extends to the entire area of ​​the side 64 of the first portion 60. The material of the second portion 70 contains a low dielectric constant material. After the material of the second portion 70 cools and solidifies, the coil 10 and core 40 with the second portion 70 formed are removed from the mold. The method of forming the second portion 70 is not limited to the method described above.

[0067] Next, a pair of terminal electrodes 20 and 30 are formed (step S13). Specifically, as follows: Figure 9 As shown, firstly, the remaining portions 16 and 17 of the winding 11 extending from the side 74 of the second part 70 to the outside of the outer casing 50 are cut off. At this time, the portions that will later become a pair of terminal electrodes 20 and 30 and connecting portions 13 and 14 are left, and the remaining portions 16 and 17 are cut off. After cutting the winding 11, the covering layer 11b at both ends of the winding 11 is removed to expose the wire 11a. The covering layer 11b can also be removed, for example, by irradiation with a laser.

[0068] Next, by squeezing and removing the two ends of the winding 11 with the covering layer 11b removed, a shape is formed as shown. Figure 10 The terminal electrodes 20 and 30 are in the shape of flat plates. At this time, terminal electrodes 20 and 30 that extend along the directions Y and Z can also be formed by pressing the two ends of the winding 11 in a clamping manner in the direction X.

[0069] Next, a pair of terminal electrodes 20 and 30 are disposed on the side 74 of the second portion 70 (step S14). Specifically, as Figure 11 As shown, the terminal electrode 20 is positioned on the side 74 by tilting it toward the side 74 of the second part 70 and bending the connecting portion 13 of the winding 11. The terminal electrode 30 is also positioned on the side 74 in the same manner as the terminal electrode 20. The process of positioning a pair of terminal electrodes 20 and 30 (step S14) may also include using an adhesive to fix the tilted terminal electrodes 20 and 30 to the side 74 of the second part 70. The manufacturing process of the coil component 1 is now complete.

[0070] Reference Figure 12 The difference in frequency characteristics between a coil component with a second portion 70 and a coil component without a second portion 70 in the outer casing 50 will be explained. The coil component with a second portion 70 in the outer casing 50 is the coil component 1 described above. In the coil component without a second portion 70 in the outer casing 50, the outer casing 50 is composed only of a first portion 60.

[0071] Figure 12 This is a diagram showing the frequency characteristics of the coil component. Figure 12 The horizontal axis represents the frequency [GHz] of the current flowing in the coil component. Figure 12 The vertical axis represents the Q value. Figure 12 The diagram shows characteristics C1 and C2. Characteristic C1 is the frequency characteristic of the coil component of the outer casing 50 having the second part 70. Characteristic C2 is the frequency characteristic of the coil component of the outer casing 50 without the second part 70.

[0072] like Figure 12 As shown, in either characteristic C1 or C2, the Q value gradually increases as the current frequency changes from the low-frequency band to the high-frequency band. However, if the current frequency exceeds a certain frequency, the Q value drops sharply and becomes zero. The frequency at which the Q value of characteristic C1 becomes zero is higher than the frequency at which the Q value of characteristic C2 becomes zero. That is, compared to the coil component of the outer casing 50 without the second part 70, the coil component of the outer casing 50 with the second part 70 also functions as a coil component at a higher frequency. It is believed that the reason why the coil component of the outer casing 50 with the second part 70 also functions as a coil component at a higher frequency is that the low dielectric constant material contained in the second part 70 reduces the stray capacitance between the terminal electrodes 20 and 30 and the coil 10, thereby suppressing the decrease in the self-resonant frequency in the coil component 1.

[0073] In the coil component 1 of this embodiment, a second portion 70 is disposed between the coil 10 and the terminal electrodes 20 and 30. This second portion 70 comprises a low-dielectric-constant material having a lower relative dielectric constant than that of the resin in the first portion 60. Therefore, the stray capacitance generated between the coil component 1 and the terminal electrodes 20 and 30 is reduced by the low-dielectric-constant material of the second portion 70, and the decrease in the self-resonant frequency in the coil component 1 is suppressed.

[0074] The coil 10 includes a winding 11. The winding 11 has a helical coil portion 12 (first winding portion) and a pair of connecting portions 13, 14 (second winding portions). Each of the pair of connecting portions 13, 14 is continuous with a corresponding terminal electrode 20, 30 of a pair of terminal electrodes 20, 30. Each terminal electrode 20, 30 has a flat plate shape.

[0075] For example, if a physical impact is applied to the coil component 1, the electrical connection between the terminal electrodes 20, 30 and the coil 10 may be severed. In a structure where the connection portions 13, 14 of the terminal electrodes 20, 30 and the winding 11 are continuous, the electrical connection between the terminal electrodes 20, 30 and the coil 10 is difficult to sever even if a physical impact is applied to the coil component 1.

[0076] The flat plate structure of each terminal electrode 20 and 30 facilitates the electrical connection between the terminal electrodes 20 and 30 and other electronic components when the coil component 1 is mounted on other electronic components.

[0077] The second part 70 includes a flat side surface 74 on which a pair of terminal electrodes 20, 30 are disposed. Each connecting part 13, 14 has: an inner portion 13a, 14a disposed within the outer casing 50; and an outer portion 13b, 14b disposed on the outer casing 50 and continuous with the corresponding terminal electrodes 20, 30. The inner portions 13a, 14a extend in a direction Z intersecting the side surface 74, and the outer portions 13b, 14b extend in a direction X along the side surface 74.

[0078] In this case, the coil 10 covered by the outer casing 50 and the terminal electrodes 20, 30 disposed on the outer casing 50 are more reliably connected by the connecting parts 13, 14.

[0079] The winding 11 has: a conductor 11a, and a covering layer 11b that covers the conductor 11a and has electrical insulation.

[0080] In this case, since the conductor 11a of the winding 11 is protected by the sheathing layer 11b, the conductor 11a is difficult to be damaged even when the winding 11 is bent.

[0081] The cladding layer 11b of the winding 11 can be made of a low-dielectric-constant material. If the cladding layer 11b is made of a low-dielectric-constant material, even when a portion of the connecting portions 13, 14 is opposite to the coil, the stray capacitance generated between the connecting portions 13, 14 and the coil 10 can be reduced by the low-dielectric-constant material of the cladding layer 11b. This suppresses the reduction of the self-resonant frequency in the coil component 1.

[0082] In the manufacturing method of the coil component 1 according to the above embodiment, a second portion 70 is formed between the coil 10 and the terminal electrodes 20 and 30 from a material containing a low dielectric constant material, which has a lower relative dielectric constant than that of the first portion 60. Therefore, the stray capacitance generated between the coil 10 and the terminal electrodes 20 and 30 is reduced by the low dielectric constant material of the second portion 70, and the decrease in the self-resonant frequency in the coil component 1 is suppressed.

[0083] In the manufacturing method of coil component 1, during the preparation of coil 10, a coil 10 composed of winding wire 11 is prepared. The manufacturing method of coil component 1 further includes, before the process of configuring a pair of terminal electrodes 20, 30, a step of forming a pair of terminal electrodes 20, 30 continuous with winding wire 11 by pressing the two ends of winding wire 11.

[0084] In this case, the process of connecting the terminal electrodes 20 and 30 to the coil 10 is not required during the manufacturing process of the coil component 1. Therefore, the manufacturing process of the coil component 1 is simplified.

[0085] Because the winding 11 and the terminal electrodes 20 and 30 are continuous, the electrical connection between the terminal electrodes 20 and 30 and the coil 10 is difficult to break even when a physical impact is applied to the coil component 1.

[0086] <Second Implementation>

[0087] Reference Figure 13 An example of the coil component 2 in the second embodiment will be described. Figure 13 This is a perspective view showing the coil component 2 according to the second embodiment. In the description of the second embodiment, the differences from the first embodiment described above are mainly explained, and common points are sometimes omitted. The main difference between the coil component 2 of this embodiment and the coil component 1 of the first embodiment lies in the structure and formation process of the terminal electrodes.

[0088] The coil component 2 includes: a coil 110, a pair of terminal electrodes 120 and 130, a core 40, and an outer casing 50. The coil 110 is composed of a winding 111. The winding 111 has a helical portion 112. Hereinafter, the portion 112 of the winding 111 will be referred to as the coil portion 112. The coil portion 112 is disposed outside the core 40. In the following description, similar to the first embodiment, the axial direction of the coil 110 is defined as direction X, the direction intersecting direction X is defined as direction Y, and the direction intersecting both direction X and direction Y is defined as direction Z. In this embodiment, direction X, direction Y, and direction Z are orthogonal to each other.

[0089] The winding 111 has a pair of connecting portions 113 and 114. The pair of connecting portions 113 and 114 are continuously provided with both ends of the coil portion 112, and electrically connect the coil 110 and a pair of terminal electrodes 120 and 130. For example, when the coil portion 112 constitutes the first winding portion, each connecting portion 113 and 114 constitutes the second winding portion.

[0090] The coil portion 112 has a plurality of turns B. That is, the coil 110 has a plurality of turns B. The plurality of turns B are arranged along the direction X. When viewed from the direction X, the area defined by each turn B has a rectangular shape with rounded corners. The shape of each turn B can also be annular. Turns B1 and B2, which are located at both ends in the direction X, are connected to terminal electrodes 120 and 130 respectively via connecting portions 113 and 114.

[0091] The connecting portions 13 and 14 of the winding 11 in the first embodiment have: inner portions 13a and 14a disposed within the outer casing 50; and outer portions 13b and 14b disposed on the outer casing 50. The connecting portions 113 and 114 of the winding 111 in this embodiment only have, as in the example... Figure 13 The inner portion shown is located within the outer casing 50 and does not have an outer portion.

[0092] The connecting portions 113 and 114 each have end faces 113a and 114a. Each end face 113a and 114a is provided in such a way that it is coplanar with the side surface 74 of the second portion 70. As a result, no step difference is generated between the end faces 113a and 114a and the side surface 74 of the second portion 70.

[0093] A pair of terminal electrodes 120 and 130 are disposed on the side surface 74 of the outer casing 50. Specifically, the pair of terminal electrodes 120 and 130 are disposed separately at their respective ends in the Y direction of the side surface 74. Each terminal electrode 120 and 130 has a flat plate shape. In a top view in the Z direction, each terminal electrode 120 and 130 has a rectangular shape. Each terminal electrode 120 and 130 is disposed on the side surface 74 with its long side along the X direction. Each terminal electrode 120 and 130 has a base end portion 121 and 131 and a front end portion 122 and 132. The surface of each base end portion 121 and 131 contacts the end faces 113a and 114a of the connecting portions 113 and 114, respectively. Thus, the pair of terminal electrodes 120 and 130 are electrically connected to the coil 110.

[0094] Each terminal electrode 120, 130 is opposite to the coil 110. In this embodiment, the two ends of each terminal electrode 120, 130 in the Y direction are opposite to the coil 110 in the Z direction. Alternatively, the entire terminal electrode 120, 130 may not be opposite to the coil 110, but at least a portion of each terminal electrode 120, 130 may be opposite to the coil 110.

[0095] Reference Figures 14-16 An example of the manufacturing method of the coil component 2 in this embodiment will be described. Figure 14 This is a flowchart illustrating the manufacturing process of the coil component 2 in this embodiment. Figure 15 and Figure 16 This is a diagram showing the manufacturing process of the coil component 2 in this embodiment.

[0096] A portion of the manufacturing process of the coil component 2 in this embodiment is common to the manufacturing process of the coil component 1 in the first embodiment. Specifically, Figure 14 The process shown is from preparing coil 110 (step S20) to forming the second part 70 (step S22). Figure 5 The process shown from preparing coil 10 (step S10) to forming the second part 70 (step S12) is common. Therefore, the description of the process from step S20 to step S22 is omitted.

[0097] At the end of the process in step S22, such as Figure 15 As shown, the winding 111 has remaining portions 116 and 117 that are continuous with both ends of the coil portion 112. The remaining portions 116 and 117 include portions that later become connecting portions 113 and 114.

[0098] Following step S22, the remaining portions 116 and 117 of the winding 111 are cut off (step S23). For example, the remaining portions 116 and 117 of the winding 111 are cut off to a degree that protrudes slightly from the side 74 of the second part 70 outwards from the outer body 50.

[0099] Next, the end face of the cut winding 111 is ground (step S24). Specifically, as follows: Figure 16 As shown, the end face of the winding 111 is ground until it is flush with the side surface 74 of the second part 70. At the end of the grinding process in step S24, the portions of the remaining parts 116 and 117 that are disposed inside the outer casing 50 function as connecting parts 113 and 114. Figure 16 As shown, the end faces 113a and 114a of the connecting portions 113 and 114 are exposed on the side surface 74 of the second portion 70.

[0100] Next, terminal electrodes 120 and 130 are positioned on the side 74 of the second portion 70 (step S25). The coil component 2 with terminal electrodes 120 and 130 positioned is as follows: Figure 14 As shown. In the first embodiment, each terminal electrode 20, 30 is formed by extruding a portion of the winding 11, but in this embodiment, each terminal electrode 120, 130 is prepared as a separate component from the winding 111.

[0101] In step S25, the terminal electrodes 120 and 130 are arranged in contact with the end faces 113a and 114a of the winding 111. Thus, each terminal electrode 120 and 130 is electrically connected to the coil 110. The process of arranging the terminal electrodes 120 and 130 (step S25) may also include fixing each terminal electrode 120 and 130 to the side surface 74 of the second part 70 using adhesive 80. The manufacturing process of the coil component 2 is now complete.

[0102] The embodiments and variations of the present invention have been described above, but the present invention is not limited to these embodiments and variations. Various changes can be made to the embodiments without departing from the spirit of the present invention.

[0103] The second part 70 is formed in direct contact with the first part 60, but other components may be interposed between the first part 60 and the second part 70.

[0104] In the manufacturing process of the coil component 1 of the first embodiment described above, after the second part 70 of the outer casing 50 is formed, a pair of terminal electrodes 20, 30 are disposed on the side 74 of the second part 70. However, the second part 70 may also be formed between the opposing coil 10 and the pair of terminal electrodes 20, 30 after the pair of terminal electrodes 20, 30 are disposed opposite to the coil 10.

Claims

1. A coil component, wherein, have: outer body; A coil, which is disposed within the outer casing; and A pair of terminal electrodes, electrically connected to the coil, are disposed on the outer casing. The long side of the terminal electrode is along the axial direction of the coil. The outer casing has: The first part, which covers the coil, is made of resin; and The second part is equipped with the pair of terminal electrodes. The second portion comprises a material having a lower relative permittivity than that of the resin, and is disposed between the coil and the pair of terminal electrodes. The dielectric constant of the resin in the first part and the dielectric constant of the material in the second part are 4 or less.

2. The coil component according to claim 1, wherein, The coil includes a winding. The winding has: a helical first winding portion and a pair of second winding portions. Each of the pair of second winding portions is continuous with the corresponding terminal electrode of the pair of terminal electrodes. Each of the terminal electrodes has a flat plate shape.

3. The coil component according to claim 2, wherein, The second part includes: a flat side surface on which the pair of terminal electrodes are disposed. Each of the second winding portions has: an inner portion disposed within the outer casing, and an outer portion disposed on the outer casing and continuous with the corresponding terminal electrode. The inner portion extends in a direction intersecting the side surface, and the outer portion extends in a direction along the side surface.

4. The coil component according to claim 2, wherein, The winding has: a conductor and a covering layer that covers the conductor and has electrical insulation.

5. The coil component according to claim 3, wherein, The winding has: a conductor and a covering layer that covers the conductor and has electrical insulation.

6. The coil component according to any one of claims 1 to 5, wherein, It also includes: a core, which is disposed inside the coil. The core is made of resin.

7. A method for manufacturing a coil component, in, include: The process of preparing the coil; The process of forming the outer casing by covering the coil; and In the process of configuring a pair of terminal electrodes that are electrically connected to the coil in the outer casing, The process of forming the outer casing includes: The process of forming a first portion of the coil covered by resin; and The process of forming a predetermined second part of the configuration of the pair of terminal electrodes from a specified material. In the process of configuring the pair of terminal electrodes, the pair of terminal electrodes are configured on the outer casing such that the second part is configured between the coil and the pair of terminal electrodes, with the long side of the terminal electrodes along the axial direction of the coil. The specified material has a lower relative permittivity than the resin. The dielectric constant of the resin in the first part and the dielectric constant of the material in the second part are 4 or less.

8. The method for manufacturing the coil component according to claim 7, wherein, In the process of preparing the coil, the process of preparing the coil consisting of a winding, prior to the process of configuring the pair of terminal electrodes, further includes a process of forming the pair of terminal electrodes continuous with the winding by pressing the two ends of the winding.

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