Manufacturing method of electronic components

Abstract

To provide a method of manufacturing an electronic component capable of downsizing the electronic component and securing characteristics of the electronic component, and of securing reliability of electrical connection between terminal electrodes and a conductive wire.SOLUTION: A method of manufacturing an electronic component includes the following steps of: preparing a molded product; irradiating the molded product with a plasma; and forming terminal electrodes on an outer surface of a resin molding part. In the molded product, a conductive wire is arranged inside the resin molding part. The resin molding part is formed of a resin. The molded product is irradiated with the plasma while directing the plasma toward end parts of the conductive wire. The terminal electrodes are in contact with the end parts of the conductive wire.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing an electronic component. [Background technology]

[0002] There are known electronic components that have conductive wires inside an element body (for example, see Patent Document 1). For example, terminal electrodes are arranged on the outer surface of the element body. The terminal electrodes are in contact with the conductive wires. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-70154 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to miniaturize electronic components and ensure their performance, further thinning of conductive wires is being considered. Therefore, even when the conductive wire is relatively thin, it is required to prevent the occurrence of poor contact between the terminal electrode and the conductive wire and to ensure the reliability of the electrical connection between the terminal electrode and the conductive wire.

[0005] At the connection portion between the terminal electrode and the tip end surface of the conductive wire, the tip end surface of the conductive wire is generally formed by mechanical processing or laser processing. However, when the conductive wire is relatively thin, mechanical processing can be difficult because the tip end surface of the conductive wire is buried in the element body. Laser processing can cause damage to the element body and the conductive wire due to a sudden rise in temperature.

[0006] One aspect of the present disclosure provides a method for manufacturing an electronic component that can achieve miniaturization of the electronic component and ensure the characteristics of the electronic component, while also ensuring the reliability of the electrical connection between the terminal electrode and the conductive wire. [Means for solving the problem]

[0007] A method for manufacturing an electronic component according to one aspect of the present disclosure includes the steps of preparing a molded article, irradiating the molded article with plasma, and forming a terminal electrode on the outer surface of a resin molded portion. In the molded article, a conductive wire is disposed inside the resin molded portion. The resin molded portion is molded from resin. The plasma is irradiated onto the molded article in a direction toward an end of the conductive wire. The terminal electrode is in contact with the end of the conductive wire.

[0008] In this method for manufacturing an electronic component, plasma is irradiated onto the molded article toward the end of the conductive wire. In this case, the end of the conductive wire can be exposed from the molded resin portion while suppressing damage to the conductive wire. By irradiating the plasma, the molded resin portion can be selectively removed from the conductive wire. As a result, it is possible to achieve miniaturization of the electronic component and ensure the characteristics of the electronic component, while also ensuring the reliability of the electrical connection between the terminal electrode and the conductive wire.

[0009] In the above-described one aspect, the conductive wire may include a conductor and an insulating coating covering the conductor. In the step of irradiating with plasma, the insulating coating covering the side surface of the conductor at the end is removed by irradiating with plasma. In this case, the insulating coating can be selectively removed from the conductive wire by irradiating with plasma.

[0010] In one of the above aspects, the plasma may be water vapor plasma. In this case, the speed at which the end of the conductive wire is exposed from the resin molding portion is increased. Oxides are reduced on the surface of the conductor at the end. Formation of an oxide film on the surface of the conductive wire can be suppressed. Therefore, manufacturing throughput can be improved, and the reliability of the electrical connection between the terminal electrode and the conductive wire can be further improved.

[0011] In the above-described one aspect, the conductive wire may form a coil inside the element body, which can ensure the characteristics of the electronic component regarding the inductance of the coil and also ensure the reliability of the electrical connection between the terminal electrode and the conductive wire.

[0012] In one embodiment, the cross-sectional area of ​​the end is 7.85×10 -11 m 2 More than 1×10 -8 m 2 The following may also be used. Even with this configuration, the end of the conductive wire can be easily exposed from the resin molded portion by irradiating plasma. This allows the electronic component to be miniaturized while maintaining the characteristics of the electronic component. For example, when the conductive wire forms a coil, the coil can have a desired inductance.

[0013] In the above-described one aspect, the area of ​​the joint surface where the conductive wire and the terminal electrode are joined may be larger than the cross-sectional area of ​​the end portion, which can further improve the reliability of the electrical connection between the conductive wire and the terminal electrode.

[0014] In the step of irradiating the plasma in the one aspect, a mask having an opening may be positioned, and the plasma passing through the opening may be irradiated onto the molded article. The opening may be disposed at a position corresponding to the position of the end portion. In this case, the position at which the plasma is irradiated onto the molded article can be highly adjusted. Therefore, the portion of the molded article that is removed by the plasma irradiation can be selectively adjusted. Therefore, the versatility of the molded article configuration is improved.

[0015] In the step of forming the terminal electrode in the above-described one aspect, the terminal electrode may be formed by sputtering. In this case, the metal constituting the terminal electrode can be formed on the surface of the end portion in an atomically dense manner. Since the surface of the end portion is prevented from being exposed to air, the formation of an oxide film on the surface of the end portion can also be prevented. Therefore, the reliability of the electrical connection between the conductive wire and the terminal electrode can be further improved.

[0016] In the step of forming the terminal electrode in the above-described one aspect, the terminal electrode may be formed by performing electroless plating followed by electrolytic plating. In this case, the electroless plating forms a metal film on the surface of the end portion more densely than the electrolytic plating, and then the film formed by the electroless plating can be thickened by the electrolytic plating. This can also improve the speed of forming the terminal electrode. Therefore, manufacturing throughput can be improved and the reliability of the electrical connection between the conductive wire and the terminal electrode can be ensured. [Effects of the Invention]

[0017] One aspect of the present disclosure provides a method for manufacturing an electronic component that can achieve miniaturization of the electronic component and ensure the characteristics of the electronic component, while also ensuring the reliability of the electrical connection between the terminal electrode and the conductive wire. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view of an electronic component according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the inside of the electronic component. [Figure 3] 10(a) and 10(b) are enlarged views of the end of a conductive wire. [Figure 4] 10(a) and 10(b) are diagrams for explaining the shape of the end of a conductive wire. [Figure 5] 10(a) and 10(b) are diagrams for explaining the shape of the end of a conductive wire. [Figure 6] 3 is a flowchart illustrating an example of a method for manufacturing an electronic component according to the present embodiment. [Figure 7] FIG. 2 is a view showing the winding core before resin molding. [Figure 8] FIG. 2 is an enlarged view of a winding core on which a coil is provided. [Figure 9] FIG. 10 shows aligned moldings. [Figure 10] FIG. 2 is a diagram showing an end face of a molded product taken along line XX after resin molding. [Figure 11]1(a) to 1(c) are diagrams illustrating a part of a method for manufacturing an electronic component. [Figure 12] FIG. 10 is a diagram showing a molded product on which a processed surface is formed. [Figure 13] FIG. 10 is a diagram for explaining a mask in plasma processing. [Figure 14] FIG. 10 is a diagram showing a molded product on which terminal electrodes are formed. [Figure 15] FIG. 10 is a diagram showing a diced chip component. [Figure 16] 10(a) and 10(b) are diagrams showing evaluation results of electronic components. [Figure 17] FIG. 10 is a diagram showing evaluation results of electronic components. [Figure 18] 10(a) and 10(b) are diagrams illustrating a method for manufacturing an electronic component according to a modified example of the present embodiment. [Figure 19] 10(a) and 10(b) are diagrams illustrating a method for manufacturing an electronic component according to a modified example of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, identical or equivalent elements are designated by the same reference numerals, and redundant description will be omitted. Furthermore, the shapes of various elements depicted in the drawings of the present disclosure do not necessarily correspond to the actual shapes of the various elements, as they may be modified for the purpose of explanation. In the present disclosure, the terms "orthogonal," "vertical," "parallel," "planar," "identical," and "equal" mean "substantially orthogonal configuration," "substantially vertical configuration," "substantially parallel configuration," "substantially planar," "substantially identical configuration," and "substantially equal," respectively, and also include configurations that deviate within a predetermined error range. The predetermined error range includes, for example, the range of manufacturing tolerance or a range greater than the manufacturing tolerance.

[0020] First, an overview of an electronic component according to an example of the present embodiment will be described with reference to Figures 1 and 2. Figure 1 is a perspective view of the electronic component according to the present embodiment. Figure 2 is a perspective view showing the inside of the electronic component. In the example shown in the present embodiment, the electronic component 1 is a coil component that forms a coil.

[0021] The electronic component 1 includes an element body 2, a pair of terminal electrodes 6, 7, and a conductive wire 9. At least a portion of the conductive wire 9 is disposed inside the element body 2.

[0022] The element body 2 has an outer surface 10. The element body 2 has, as its outer surface 10, a pair of end faces 10a, a pair of side faces 10b, and a pair of side faces 10c. The pair of end faces 10a face each other in the longitudinal direction D1. The pair of side faces 10b face each other in the height direction D2. The pair of side faces 10c face each other in the width direction D3. The pair of end faces 10a and the pair of side faces 10b are aligned along the width direction D3. The outer surface 10 of the element body 2 includes at least one flat surface. For example, each of the pair of end faces 10a, the pair of side faces 10b, and the pair of side faces 10c is a flat surface.

[0023] In one example shown in this embodiment, the element body 2 has a rectangular parallelepiped shape in which the length in the height direction D2 is smaller than the length in the longitudinal direction D1, and the length in the width direction D3 is smaller than the length in the height direction D2. The rectangular parallelepiped shape includes a rectangular parallelepiped shape with chamfered corners and ridges, and a rectangular parallelepiped shape with rounded corners and ridges. The element body 2 is formed from, for example, resin. As a variation of this embodiment, the element body 2 may have a rectangular parallelepiped shape in which the length in the height direction D2 is smaller than the length in the longitudinal direction D1, and the length in the width direction D3 is smaller than the length in the height direction D2.

[0024] The pair of terminal electrodes 6, 7 are arranged on the same plane. For example, the pair of terminal electrodes 6, 7 are arranged on the same side surface 10b. The terminal electrode 6 has a main surface 6a. The terminal electrode 7 has a main surface 7a. The main surface 6a and the main surface 7a are in contact with the same side surface 10b. The pair of terminal electrodes 6, 7 are arranged, for example, at both ends of the side surface 10b of the element body 2 in the longitudinal direction D1. The pair of terminal electrodes 6, 7 are spaced apart from each other and arranged in the longitudinal direction D1. Each of the terminal electrodes 6, 7 has, for example, a rectangular shape in a plan view.

[0025] The terminal electrodes 6, 7 are formed by known techniques. For example, the terminal electrodes 6, 7 are formed by sputtering. As a variation of this embodiment, the terminal electrodes 6, 7 may be formed by plating. The plating may be electroless plating or electrolytic plating. Electroless plating may be followed by electrolytic plating. As a variation of this embodiment, the terminal electrodes 6, 7 include, for example, a resin electrode. The terminal electrodes 6, 7 may be composed of, for example, only a resin electrode. As a variation of this embodiment, the terminal electrodes 6, 7 may be formed by applying an electrode paste to the element body 2 and then drying it. The electrode paste is, for example, a silver paste. As a variation of this embodiment, the terminal electrodes 6, 7 may be solder. The terminal electrodes 6, 7 may be formed by a combination of the various techniques described above. The terminal electrodes 6, 7 formed by the various techniques described above may further be plated.

[0026] The conductive wire 9 includes a main body 11 and a pair of end portions 12 and 13. The main body 11 is located inside the element body 2. The pair of end portions 12 and 13 are each connected to the main body 11. At least a portion of the pair of end portions 12 and 13 is exposed from the element body 2. In other words, at least a portion of the pair of end portions 12 and 13 is located outside the element body 2. In other words, the portion of the conductive wire 9 other than the pair of end portions 12 and 13 is covered by the element body 2. In this disclosure, "connected" includes the meaning of a physically connected state and the meaning of a physically separated but electrically connected state. "Physically connected" includes the meaning of separate and distinct components being in contact with each other and the meaning of an integrated state. "Electrically connected" means being electrically conductive. "Connected" means being integrated using the same or different materials. In other words, "connected" means being continuously formed.

[0027] The pair of ends 12, 13 are spaced apart from each other. The pair of ends 12, 13 are respectively connected to different terminal electrodes 6, 7. For example, the end 12 is connected to the terminal electrode 6. The end 13 is connected to the terminal electrode 7. Each of the ends 12, 13 forms a pair of tips of the conductive wire 9. The pair of ends 12, 13 are exposed from the element body 2 at the same side surface 10b. For example, the end 12 is connected to the main surface 6a of the terminal electrode 6. The end 13 is connected to the main surface 7a of the terminal electrode 7.

[0028] In the example shown in this embodiment, the main body 11 includes a coil 15. In other words, the conductive wire 9 forms the coil 15 inside the element body 2. The coil 15 forms, for example, a coil axis that is aligned with the width direction D3. In other words, the coil axis of the coil 15 extends in the width direction D3.

[0029] Next, the detailed configuration of the electronic component 1 will be described with reference to Figures 1 to 3. The element body 2 includes a core portion 31 and a resin molded portion 32. In Figure 2, the resin molded portion 32 is indicated by a two-dot chain line. The core portion 31 and the resin molded portion 32 are, for example, integrally molded using the same material. As a variation of this embodiment, the core portion 31 and the resin molded portion 32 may be molded as separate bodies using the same material or different materials. Even when the core portion 31 and the resin molded portion 32 are molded as separate bodies, the core portion 31 and the resin molded portion 32 may be formed so that the boundary between the core portion 31 and the resin molded portion 32 is not visible.

[0030] The core portion 31 corresponds to a winding core around which the main body portion 11 of the conductive wire 9 is wound. The core portion 31 extends, for example, in the width direction D3. The resin molded portion 32 covers the main body portion 11 of the conductive wire 9. The resin molded portion 32 covers at least a portion of the core portion 31. In the present disclosure, "covering" means to surround the object so that it cannot be seen. "Covering" includes not only direct contact with the object but also separation from the object. For example, the resin molded portion 32 may cover the object from above another member, or may have a portion where the object and the resin molded portion 32 are not in direct contact. For example, the core portion 31 may be covered by the resin molded portion 32 from above the conductive wire 9 wound around the core portion 31, and may have a portion where the core portion 31 and the resin molded portion 32 are not in direct contact. In one example shown in the present embodiment, the resin molded portion 32 is formed to contact the conductive wire 9.

[0031] The core portion 31 and the molded resin portion 32 may be formed solely from resin, for example. The material of the core portion 31 and the molded resin portion 32 includes, for example, at least one of a thermosetting resin and a thermoplastic resin. The material of the core portion 31 and the molded resin portion 32 includes, as a thermosetting resin, at least one selected from the group consisting of an epoxy resin, a polyimide resin, a phenolic resin, and an unsaturated polyester resin. The polyimide resin is, for example, a bismaleimide resin. The material of the core portion 31 and the molded resin portion 32 includes, as a thermoplastic resin, at least one selected from the group consisting of a crystalline polystyrene, a fluororesin, a liquid crystal polymer, and polyphenylene sulfide (PPS). The fluororesin is, for example, a polytetrafluoroethylene (PTFE) resin.

[0032] In one example shown in this embodiment, the resin molded portion 32 forms a pair of end faces 10a, a pair of side faces 10b, and a pair of side faces 10c. The entire outer surface 10 of the element body 2 is formed by the resin molded portion 32. In a modification of this embodiment, the core portion 31 may be exposed from the resin molded portion 32. In this case, the outer surface 10 of the element body 2 is formed by the resin molded portion 32 and the core portion 31. For example, the core portion 31 may form at least a portion of the pair of side faces 10c.

[0033] The core portion 31 is located inside the coil 15. The core portion 31 extends along the coil axis of the coil 15. The core portion 31 is in contact with the coil 15. In one example shown in this embodiment, the core portion 31 includes a shaft portion 41 and a pair of side end portions 42. The shaft portion 41 and the pair of side end portions 42 are integrally formed with each other, for example, from the same material. As a modification of this embodiment, the shaft portion 41 and the pair of side end portions 42 may be formed from different materials. The shaft portion 41 has a columnar shape. The shaft portion 41 extends, for example, in the width direction D3. Each side end portion 42 has a plate shape. The pair of side end portions 42 face each other in the width direction D3. The pair of side end portions 42 are connected by the shaft portion 41.

[0034] In one example shown in this embodiment, for example, a conductive wire 9 is wound around the shaft portion 41. The shaft portion 41 is covered with the resin molded portion 32. The shaft portion 41 is covered with the resin molded portion 32 from above the conductive wire 9, and there may be a portion where the resin molded portion 32 and the shaft portion 41 are not in direct contact with each other. At least a portion of the pair of side end portions 42 is exposed from the resin molded portion 32. Each side end portion 42 forms a side surface 10c of the element body 2. Each side end portion 42 forms a portion of the pair of end faces 10a and a portion of the pair of side surfaces 10b.

[0035] In one example shown in this embodiment, the coil 15 of the conductive wire 9 is provided on the shaft portion 41. The coil 15 is wound around the shaft portion 41 in the circumferential direction of the shaft portion 41. The coil 15 is wound spirally around the shaft portion 41, with the shaft portion 41 as its axis. The coil axis of the coil 15 is aligned with the extension direction of the shaft portion 41. The coil axis of the coil 15 corresponds to the axis of rotation around which the conductive wire 9 is wound when the coil 15 is formed.

[0036] The conductive wire 9 includes, for example, a conductor 21 and an insulating coating 22. The conductor 21 corresponds to the core of the conductive wire 9. The insulating coating 22 covers the side surface of the conductor 21. In the conductive wire 9, at least a portion of the conductor 21 at each of the ends 12 and 13 is exposed from the insulating coating 22. The conductor 21 at each of the ends 12 and 13 is connected to the terminal electrodes 6 and 7, respectively.

[0037] The material of the conductor 21 includes at least one selected from the group consisting of oxygen-free copper, tough pitch copper, phosphorus-deoxidized copper, and copper-silver alloy. The material of the insulating coating 22 includes at least one selected from the group consisting of polyurethane, polyvinyl formal, polyester, polyesterimide, polyamideimide, and polyimide.

[0038] In one example shown in this embodiment, as shown in FIG. 3(a), each end 12, 13 protrudes from the outer surface 10 of the element body 2 and extends in a direction intersecting the outer surface 10 outside the element body 2. FIG. 3(a) is an enlarged view of the end 12 in one example shown in this embodiment. FIG. 3(a) exemplarily shows the configuration of the end 12, but the end 13 also has a similar configuration. For example, each end 12, 13 protrudes from one side surface 10b of the element body 2 and extends in a direction intersecting the side surface 10b. For example, the entirety of each end 12, 13 is exposed from the element body 2. Each end 12, 13 extends in a direction perpendicular to the side surface 10b.

[0039] The end 12 includes a tip surface 52a and a side surface 52b. The end 13 includes a tip surface 53a and a side surface 53b. The tip surfaces 52a, 53a and the side surfaces 52b, 53b are formed by the conductor 21. In each of the end portions 12, 13, the side surfaces 52b, 53b of the conductor 21 are exposed from the insulating coating 22. In the example shown in this embodiment, each of the end portions 12, 13 includes the insulating coating 22. In other words, the portion of the conductor 21 covered with the insulating coating 22 is also exposed from the element body 2. The tip surfaces 52a, 53a and the side surfaces 52b, 53b correspond to the exposed surfaces of the conductor 21 that are exposed from the element body 2.

[0040] As a modification of this embodiment, each of the end portions 12, 13 may not include the insulating coating 22. In this modification, the entirety of each of the end portions 12, 13 is exposed from the insulating coating 22. In other words, each of the end portions 12, 13 may be entirely exposed from the element body 2, and each of the end portions 12, 13 may be composed of only the conductor 21.

[0041] The tip surfaces 52a and 53a, for example, intersect with the extending directions of the end portions 12 and 13, respectively. For example, the tip surfaces 52a and 53a are along the side surface 10b. The side surfaces 52b and 53b are along the extending directions of the end portions 12 and 13, respectively. For example, the side surfaces 52b and 53b intersect with the side surface 10b of the element body 2.

[0042] For example, as shown in FIG. 4(a), the tip surfaces 52a and 53a have a circular shape when viewed from the extending direction of the end portions 12 and 13, respectively. For example, the cross section of the conductive wire 9 also has a circular shape. The diameter of the conductive wire 9 is, for example, 10 μm or more and 100 μm or less. For example, the diameter of the conductor 21 of the conductive wire 9 is, for example, 10 μm or more and 100 μm or less. For example, each of the end portions 12 and 13 has a cylindrical shape.

[0043] As a modification of this embodiment, the tip surfaces 52a and 53a may have a polygonal shape when viewed from the direction in which the end portions 12 and 13 extend, as shown in FIGS. 4(b), 5(a), and 5(b). For example, the cross section of the conductive wire 9 may also have a polygonal shape. For example, as shown in FIGS. 4(b) and 5(b), the tip surfaces 52a and 53a may have a rectangular shape when viewed from the direction in which the end portions 12 and 13 extend. As shown in FIGS. 4(b), 5(a), and 5(b), each of the end portions 12 and 13 may have a polygonal columnar shape.

[0044] In FIG. 4(b), the tip surfaces 52a and 53a have a square shape when viewed from the direction in which the end portions 12 and 13 extend. For example, the cross section of the conductive wire 9 also has a square shape. In FIG. 5(b), the tip surfaces 52a and 53a have a rectangular shape when viewed from the direction in which the end portions 12 and 13 extend. For example, the cross section of the conductive wire 9 also has a rectangular shape. In FIG. 5(a), the tip surfaces 52a and 53a have a pentagonal shape when viewed from the direction in which the end portions 12 and 13 extend. For example, the cross section of the conductive wire 9 also has a pentagonal shape. For example, when the cross section of the conductive wire 9 is square, one side of the cross section of the conductive wire 9 is, for example, 10 μm or more and 100 μm or less. For example, one side of the cross section of the conductor 21 of the conductive wire 9 is, for example, 10 μm or more and 100 μm or less.

[0045] When viewed from the height direction D2, the ends 12 and 13 are arranged along a direction intersecting the pair of side surfaces 10c. For example, when viewed from the height direction D2, the end 12 is closer to one of the pair of side surfaces 10c, and the end 13 is closer to the other of the pair of side surfaces 10c. When viewed from the height direction D2, the end 12 is closer to one of the pair of end surfaces 10a, and the end 13 is closer to the other of the pair of end surfaces 10a.

[0046] The areas of the tip surfaces 52a and 53a of the end portions 12 and 13 are, for example, equal to the cross-sectional area of ​​each end portion 12 and 13. The cross-sectional area of ​​each end portion 12 and 13 is, for example, 7.85×10 -11 m 2 More than 1×10 -8 m 2 For example, the cross-sectional area of ​​the conductor 21 at each end 12, 13 is 7.85 x 10 -11 m 2 More than 1×10 -8 m 2 or less. The length h of the portion of each end 12, 13 protruding from the outer surface 10 is, for example, 2 μm or more. In the extension direction of the end 12, 13, the length of the side surface 52b, 53b is, for example, 2 μm or more. In this disclosure, the "cross-sectional area" refers to the area of ​​a cross section. In this disclosure, the "cross section" refers to a cross section in a direction perpendicular to the extension direction of the target portion.

[0047] The length h of the portion of each end 12, 13 protruding from the outer surface 10 may be 4.5 μm or more. In this case, the bonding area between the conductive wire and the terminal electrode is more likely to be ensured, and the reliability of the electrical connection can be further improved.

[0048] The length h of the portion of each end 12, 13 protruding from the outer surface 10 is, for example, 1 mm or less. In this case, the bonding area between the conductive wire and the terminal electrode can be secured, and the electronic component can be made smaller.

[0049] As a modification of this embodiment, as shown in FIG. 3(b), the end portions 12, 13 may not protrude from the outer surface 10 of the element body 2. FIG. 3(b) is an enlarged view of the end portion 12 in this modification. FIG. 3(b) exemplarily shows the configuration of the end portion 12 in this modification, but the end portion 13 also has a similar configuration. FIG. 3(b) is an enlarged view of the end portion 12. In this case, the end portions 12, 13 extend in a direction intersecting the outer surface 10 inside the element body 2. In this modification, the end portions 12, 13 extend in a direction perpendicular to the side surface 10b inside the element body 2.

[0050] In the modification shown in Figure 3(b), the tip surfaces 52a, 53a are formed flush with the side surface 10b of the outer surface 10. In this case, the ends 12, 13 include the tip surfaces 52a, 53a but do not include the side surfaces 52b, 53b.

[0051] As a further modification of this embodiment, each of the ends 12, 13 may be exposed from one of the side surfaces 10b of the element body 2 and extend along the side surface 10b. In this case, the conductor 21 of each of the ends 12, 13 includes an exposed surface that extends along the side surface 10b. The area of ​​the exposed surface is larger than the cross-sectional area of ​​the conductive wire 9. Even in this case, each of the ends 12, 13 may protrude from the side surface 10b of the outer surface 10, may be formed flush with the side surface 10b of the outer surface 10, or may be recessed relative to the side surface 10b of the outer surface 10.

[0052] The pair of terminal electrodes 6, 7 are connected to ends 12, 13 of the conductive wire 9, respectively. The pair of terminal electrodes 6, 7 are electrically connected to the coil 15 via the ends 12, 13. The terminal electrode 6 covers the end 12 and is in contact with it. The terminal electrode 6 is joined to the end 12 at a tip surface 52a and a side surface 52b. The terminal electrode 7 covers the end 13 and is in contact with it. The terminal electrode 7 is joined to the end 13 at a tip surface 53a and a side surface 53b.

[0053] Next, an example of a method for manufacturing the electronic component in the above-described embodiment will be described with reference to Fig. 6 to Fig. 15. Fig. 6 is a flowchart showing an example of a method for manufacturing the electronic component 1. Figs. 7 to 15 are views showing some of the steps in the example of a method for manufacturing the electronic component 1. In Fig. 6 to Fig. 15, the X-axis direction, Y-axis direction, and Z-axis direction are perpendicular to one another.

[0054] First, the coil 15 is formed (step S1). FIG. 7 shows a winding core 60 on which the coil 15 is provided. The winding core 60 extends, for example, in the X-axis direction. In the following description of the manufacturing method, the X-axis direction corresponds to the axial direction of the winding core 60. The multiple winding cores 60 are arranged in the Y-axis direction in the same direction by a chuck 65. The winding cores 60 have a columnar shape. The winding cores 60 contain, for example, resin.

[0055] The winding core 60 is formed, for example, by powder injection molding. The material of the winding core 60 is, for example, a low-dielectric material. The low-dielectric material is, for example, a material with a dielectric constant of 4.0 or less. The material of the winding core 60 includes, for example, at least one of a thermosetting resin and a thermoplastic resin. The material of the winding core 60 includes, as the thermosetting resin, at least one selected from the group consisting of an epoxy resin, a polyimide resin, a phenolic resin, and an unsaturated polyester resin. The polyimide resin is, for example, a bismaleimide resin. The material of the winding core 60 includes, as the thermoplastic resin, at least one selected from the group consisting of a crystalline polystyrene, a fluororesin, a liquid crystal polymer, and a PPS. The fluororesin is, for example, a PTFE resin.

[0056] The winding core 60 includes a plurality of guide portions 61 and a plurality of shaft portions 62. The guide portions 61 and the shaft portions 62 are connected to each other. In each winding core 60, the plurality of guide portions 61 and the plurality of shaft portions 62 are alternately positioned. For example, the conductive wire 64 is wound around the winding core 60 by a spindle winding method. A plurality of coils 15 are formed by winding the conductive wire 64 around each shaft portion 62. The cross-sectional area of ​​the conductor in the conductive wire 64 is 7.85×10-11 m 2 More than 1×10 -8 m 2 The following is the result.

[0057] The guide portion 61 guides the direction in which the conductive wire 64 forming the coil 15 extends. A portion of the conductive wire 64 corresponds to the conductive wire 9 of the electronic component 1. The winding core 60 includes a plurality of shaft portions 62 in the X-axis direction. In one example shown in this embodiment, one winding core 60 includes five shaft portions 62 arranged in the X-axis direction. Each shaft portion 62 has a columnar shape and extends in the X-axis direction. Each shaft portion 62 corresponds to the shaft portion 41 of the electronic component 1 described above.

[0058] FIG. 8 is an enlarged view of the winding core 60 after the coil 15 has been formed. For example, the conductive wire 64 includes connection portions 71a and 71b, which are connected to both ends of the coil 15, respectively. The connection portions 71a and 71b are connected to the ends of adjacent coils 15 or conductive wires 64. The connection portion 71a is connected to one end of the coil 15, and the connection portion 71b is connected to the other end of the coil 15. In step S1, the connection portions 71a and 71b are formed to extend from the coil 15 in the radial direction of the shaft portion 62. In the example shown in this embodiment, the connection portions 71a and 71b extend from the coil 15 in the same direction. The connection portions 71a and 71b extend in the Z-axis direction. The connection portion 71a is guided along the guide portion 61 from the shaft portion 62 onto the stepped portion 61c of the guide portion 61.

[0059] Next, a molded product 76 is formed in which the conductive wire is sealed with resin (step S2). In step S2, for example, at least a portion of the conductive wire 64 and at least a portion of the winding core 60 are covered with resin. As a result, a resin molded portion 75 molded from resin is provided on the winding core 60, and the molded product 76 is formed. The molded product 76 includes the resin molded portion 75 and the conductive wire 64. In the molded product 76, the conductive wire 64 is disposed inside the resin molded portion 75. Step S2 corresponds to a step of preparing the molded product 76.

[0060] Inside the molded product 76, the conductive wire 64 forms a coil 15. In the molded product 76 formed in step S2, a resin molded portion 75 covers the coil 15. A portion of the resin molded portion 75 corresponds to the resin molded portion 32 of the electronic component 1. The molded product 76 includes a plurality of coils 15 and a plurality of resin molded portions 32. FIG. 9 shows an arrangement of a plurality of molded products 76 formed by resin molding. FIG. 10 shows an end face of the molded product 76 taken along line XX in FIG. 8. In FIG. 10, the resin molded portion 75 molded in step S2 is indicated by dotted hatching.

[0061] In forming the resin molded portion 75 in step S2, for example, the winding core 60 around which the conductive wire 64 is wound is placed in a mold, and the mold is filled with a liquid thermosetting resin. For example, the mold filled with the resin is placed in an oven. The resin filled in the mold is dried in a heated state in the oven, and then hardened by further heating. As a result, the resin molded portion 75 is formed.

[0062] For example, in step S2, a portion of the guide portion 61, the coil 15, and the shaft portion 62 are covered with a resin molded portion 75. For example, in step S2, the winding core 60 around which the conductive wire 64 is wound is resin molded along an edge γ1 of the guide portion 61. Immediately after the resin molding in step S2, a molding surface 76a is formed. At the molding surface 76a, a portion of the guide portion 61 is exposed from the resin molded portion 75. As shown in FIG. 10 , the edge γ1 extends along the molding surface 76a and overlaps with the molding surface 76a.

[0063] Next, the unnecessary portion 80 in the molded product 76 is removed (step S3). Figures 11(a) and 12 show the molded product 76 from which the unnecessary portion 80 has been removed. For example, after a plurality of molded products 76 are aligned as shown in Figure 9, the unnecessary portion 80 is removed from the plurality of molded products 76. For example, the plurality of molded products 76 are arranged in the same orientation. For example, the plurality of molded products 76 are arranged so that the molding surfaces 76a of the plurality of molded products 76 are flush with each other. The unnecessary portion 80 is one piece or one lump. The unnecessary portions 80 are removed in parallel from the plurality of molded products 76.

[0064] By removing the unnecessary portions 80, a processed surface 78 is formed on each molded product 76. By removing the unnecessary portions 80, the conductive wire 64 is separated into multiple pieces. By removing the unnecessary portions 80, portions of the connecting portions 71a and 71b are removed. The processed surface 78 is perpendicular to the extending direction of the connecting portions 71a and 71b. By forming the processed surface 78, a pair of end portions 66 and 67 is formed on each of the separated multiple conductive wires 64. The processed surface 78 is, for example, composed of the resin molded portion 75 and the pair of end portions 66 and 67 exposed from the resin molded portion 75. For example, the pair of end portions 66 and 67 protrude from the processed surface 78 and extend in a direction intersecting the processed surface 78. For example, the pair of end portions 66 and 67 protrude from the processed surface 78 in the Z-axis direction. For example, a portion of each conductive wire 64 corresponds to the conductive wire 9. At least a portion of the pair of end portions 66 and 67 corresponds to the pair of end portions 12 and 13 of the conductive wire 9.

[0065] On the processed surface 78, the ends 66 of the plurality of conductive wires 64 are arranged in the X-axis direction. On the processed surface 78, the ends 67 of the plurality of conductive wires 64 are arranged in the X-axis direction. The row in which the plurality of ends 66 are arranged and the row in which the plurality of ends 67 are arranged are aligned parallel to the Y-axis direction.

[0066] For example, the surface of the molded product 76 is scraped off by polishing the molded product 76, and unnecessary portions 80 are removed. The processed surface 78 is a polished surface obtained by polishing the molded product 76. For example, a portion of the molded product 76 where the conductive wire 64 is covered by the resin molded portion 75 is polished. By this polishing, the conductive wire 64 is cut, and the processed surface 78 is formed.

[0067] For example, by this polishing, the molded product 76 is ground in a direction opposite to the radial direction of the shaft portion 62. For example, by polishing, the guide portion 61 is ground in the direction of arrow α from edge γ1 to edge γ2 in FIG. 10. This forms a machined surface 78. The arrow α is aligned with the Z-axis direction. The edge γ2 is aligned with the stepped portion 61c.

[0068] For example, the molded product 76 is polished by a polishing machine 85. The polishing machine 85 is, for example, a flat polishing machine. The polishing machine 85 has a rotating surface 85a. The polishing machine 85 polishes by bringing the rotating surface 85a into contact with the object. For example, in step S3, the rotating surface 85a is brought into contact with the molding surface 76a of the molded product 76, thereby forming a processed surface 78. For example, unnecessary portions 80 of the arranged multiple molded products 76 are removed in parallel. In other words, the aligned multiple molded products 76 are polished at the same time in step S3. The processed surface 78 is, for example, a plane along the extension direction of the winding core 60.

[0069] Next, plasma treatment is performed (step S4). For example, by plasma treatment of the molded product 76 from which the unnecessary portion 80 has been removed, the ends 12 and 13 of the conductive wire 9 are formed as shown in FIG. 11(b). For example, by irradiating the processing surface 78 with plasma, the ends 12 and 13 of the conductive wire 9 are formed. For example, by irradiating the pair of ends 66 and 67 of the conductive wire 64 with plasma, the ends 12 and 13 are formed.

[0070] The plasma irradiation removes a portion of the molded resin portion 75 and a portion of the insulating coating 22 formed on the conductive wire 64, thereby forming the outer surface 10 and the end portions 12 and 13. For example, the plasma irradiation removes the insulating coating 22 covering the side surfaces 52b and 53b of the conductor 21 at the end portions 12 and 13. In step S4, the outer surface of the molded article 76 corresponds to the outer surface 10. The formed end portions 12 and 13 protrude from the outer surface 10 and extend in a direction intersecting the outer surface 10. For example, when the end portion 66 protrudes from the outer surface 10, the length h of the portion of the end portion 12 protruding from the outer surface 10 is greater than the length of the portion of the end portion 66 protruding from the outer surface 10. For example, when the end portion 67 protrudes from the outer surface 10, the length h of the portion of the end portion 13 protruding from the outer surface 10 is greater than the length of the portion of the end portion 67 protruding from the outer surface 10.

[0071] 3(b), in a modification of this embodiment, the end portions 12, 13 formed in step S4 may not protrude from the outer surface 10 of the resin molded portion 75. In this modification, the tip surfaces 52a, 53a are formed flush with the side surface 10b of the outer surface 10. In this case, the end portions 12, 13 formed in step S4 include the tip surfaces 52a, 53a but do not include the side surfaces 52b, 53b.

[0072] At the ends 12 and 13 formed in step S4, the cross-sectional area is 7.85×10 -11 m 2 More than 1×10 -8 m 2 As shown in Fig. 3, in the end portions 12, 13 formed in step S4, the length h of the portion of the end portions 12, 13 that protrudes from the outer surface 10 is 2 µm or more.

[0073] For example, a mask 86 and a jig 87 shown in Fig. 13 are used for the plasma irradiation. The mask 86 defines the region of the molded article 76 to be irradiated with the plasma. The mask 86 has a plurality of openings 89. The jig 87 positions the plurality of molded articles 76 formed in step S3. The jig 87 is arranged so that the processing surface 78 faces the mask 86. The plurality of openings 89 are arranged at positions corresponding to the positions of the ends 66, 67.

[0074] For example, the molded product 76 formed in step S3 is placed between a pair of electrodes. For example, the molded product 76 is placed on one side of the pair of electrodes. A jig 87 is placed on one side of the pair of electrodes. The jig 87 is placed so that the processing surface 78 faces the other of the pair of electrodes. A mask 86 is placed between the other of the electrodes and the molded product 76.

[0075] For example, the mask 86 is fixed to a jig 87. The openings 89 are arranged so that, when the mask 86 is fixed to the jig 87, each opening 89 overlaps with the end portions 66, 67 as viewed from the Z-axis direction. In other words, the mask 86 is positioned so that the plasma of the molded article 76 that has passed through each opening 89 is irradiated onto the end portions 66, 67. The plasma treatment performed in step S4 is, for example, a water vapor plasma treatment. In this case, the water vapor plasma is irradiated toward the molded article 76.

[0076] Next, terminal electrodes 91 are formed (step S5). As shown in FIG. 14, a plurality of terminal electrodes 91 are formed on the molded product 76 formed in step S4. The plurality of terminal electrodes 91 are spaced apart from one another. The plurality of terminal electrodes 91 are formed on the outer surface 10. The plurality of terminal electrodes 91 extend parallel to one another in the X-axis direction. The plurality of terminal electrodes 91 are arranged in the Y-axis direction. Each terminal electrode 91 covers and contacts the end portions 12, 13. Each terminal electrode 91 contacts the tip surface 52a and the side surface 52b of the end portions 12, 13. The area of ​​the joint surface where the conductive wire 64 and the terminal electrode 91 are joined may be larger than the cross-sectional area of ​​the end portions 12, 13.

[0077] For example, the terminal electrodes 91 are formed by sputtering. For example, a mask is placed on the molded product 76 on which the end portions 12, 13 have been formed in step S4, and then the terminal electrodes 91 are formed. The mask has, for example, openings provided in areas where the terminal electrodes 91 are to be formed. Some of the terminal electrodes 91 correspond to the terminal electrodes 6, 7 of the electronic component 1. After the end portions 12, 13 of the conductive wire 9 are formed by the plasma treatment in step S4 without being exposed to air, sputtering in step S5 may be performed without exposing the surfaces of the end portions 12, 13 formed in step S4 to air.

[0078] As a modification of this embodiment, the terminal electrodes 91 may be formed by plating. For example, the terminal electrodes 91 may be formed by performing electroless plating followed by electrolytic plating. The electroless plating may include acid treatment of the surfaces of the ends 12 and 13.

[0079] As another modification of this embodiment, each terminal electrode 91 may be formed by applying an electrode paste to the element body 2 and then drying it. The electrode paste may be applied to the element body 2 by, for example, a screen printing method. The electrode paste may be, for example, a silver paste. Each terminal electrode 91 may also be formed by soldering. After the terminal electrodes 91 are formed by the above process, the terminal electrodes 91 may be further subjected to a plating process.

[0080] Next, dicing is performed (step S6). FIG. 15 shows a plurality of chip components 93 after dicing. In step S6, the molded product 76 having the plurality of terminal electrodes 91 formed thereon is cut to form a plurality of chip components 93. By cutting in the Y-axis direction by dicing, the coils 15 are separated from one another together with the resin molded portion 75. By cutting in the Y-axis direction, a portion of the guide portion 61 and a portion of each terminal electrode 91 are removed. For example, the molded product 76 and the terminal electrode 91 are cut together to form a plurality of chip components 93 having the terminal electrodes 6 and 7 formed thereon.

[0081] In this embodiment, the guide portion 61 is cut so that each chip component 93 includes a step portion 61c where the chip component 93 is connected to the shaft portion 62. This step portion 61c corresponds to the side end portion 42 of the core portion 31. In a modification of this embodiment, dicing may be performed so that the entire guide portion 61 is removed from each chip component 93. The pair of terminal electrodes 6, 7 of each chip component 93 may be plated. This plating process may be electrolytic plating or electroless plating.

[0082] As described above, the electronic component 1 is formed, for example, by steps S1 to S6. In the method for manufacturing the electronic component 1, some of steps S1 to S6 may be omitted, or some of steps S1 to S6 may be replaced with different steps, and the order of the steps is not limited to the order described above. The multiple terminal electrodes 91 may be formed by a method other than sputtering. For example, the multiple terminal electrodes 91 may be formed by plating. The multiple terminal electrodes 91 may be formed by applying an electrode paste to the element body 2 and then drying it. The electrode paste is applied to the element body 2 by, for example, screen printing. The terminal electrodes 91 may be, for example, solder.

[0083] Next, the effects of the electronic component 1 and the method for manufacturing the electronic component 1 according to this embodiment and the modified examples will be described.

[0084] When the machined surface 78 is formed by the grinder 85 in step S3 and the terminal electrode 91 is formed on the machined surface 78, the ends 12, 13 of the conductive wire 64 may be embedded in the molded resin portion 75. Mechanical processing using the grinder 85 or the like stretches the resin of the molded resin portion 75, which may remain in the unevenness of the conductor 21 of the conductive wire 64. Therefore, it is difficult to expose the tip end surface of the conductive wire 64 from the molded resin portion 75 by mechanical processing. It is also difficult to remove the insulating coating 22 of the conductive wire 64 by mechanical processing. Laser processing may cause damage to the molded resin portion 75 and the conductive wire 64 due to a sudden rise in temperature.

[0085] Even if the resin molding 75 covering the conductive wire 64 and the insulating coating 22 of the conductive wire 64 are removed, the formation of an oxide film will degrade the characteristics. If the end portions 12, 13 are formed by plasma irradiation, the oxide film can be removed and the formation of the oxide film can also be suppressed.

[0086] In the method for manufacturing electronic component 1, plasma is irradiated onto molded article 76 toward ends 12, 13 of conductive wire 64. In this case, ends 12, 13 of conductive wire 64 can be exposed from molded resin portion 75 while suppressing damage to conductive wire 64. By irradiating plasma, molded resin portion 75 can be selectively removed from over conductive wire 64. Even when the cross-sectional area of ​​conductive wire 64 is relatively small, i.e., when conductive wire 64 is relatively thin, ends 12, 13 can be formed that are appropriately exposed from molded resin portion 75. As a result, it is possible to achieve a reduction in the size of electronic component 1 and to ensure the characteristics of the electronic component, while also ensuring the reliability of the electrical connection between terminal electrodes 6, 7 and conductive wire 64.

[0087] In the above-described manufacturing method, the plasma may be water vapor plasma. Water vapor plasma cleans organic matter five times faster than hydrogen plasma. This increases the processing speed of the process for forming the ends 12, 13 of the conductive wire 9 compared to other plasma processes, such as hydrogen plasma processing. Oxides are reduced on the surface of the conductor 21 at the ends 12, 13. The formation of an oxide film on the surface of the conductor 21 can also be suppressed. The surface of the conductor 21 is modified and made hydrophilic. Improving the hydrophilicity of the conductor 21 can improve the adhesion of the terminal electrodes 6, 7. For example, when the terminal electrodes 6, 7 are formed using plating or silver paste, the adhesion of the terminal electrodes 6, 7 can be improved. This improves manufacturing throughput and further improves the reliability of the electrical connection between the terminal electrodes and the conductive wire.

[0088] The cross-sectional area of ​​the ends 66 and 67 is 7.85 x 10 -11 m 2 More than 1×10 -8 m 2Even with this configuration, ends 12, 13 of conductive wire 64 can be easily exposed from resin molded portion 75 by irradiating plasma. This allows for miniaturization of electronic component 1 while maintaining the characteristics of electronic component 1. For example, when conductive wire 9 forms a coil, desired inductance can be ensured in coil 15.

[0089] The area of ​​the joint surface where the conductive wire 64 and the terminal electrodes 6, 7 are joined may be larger than the cross-sectional area of ​​the ends 12, 13. In this case, the reliability of the electrical connection between the conductive wire 64 and the terminal electrodes 6, 7 can be further improved.

[0090] In the plasma irradiation step in the above-described manufacturing method, a mask 86 having openings 89 is positioned, and the plasma passing through the openings 89 is irradiated onto the molded article 76. The openings 89 are disposed at positions corresponding to the positions of the ends 12 and 13. In this case, the position at which the plasma is irradiated onto the molded article 76 can be precisely adjusted. Therefore, the portion of the molded article 76 that is removed by the plasma irradiation can be selectively adjusted. This improves the versatility of the configuration of the molded article 76.

[0091] In the step of forming the terminal electrode 91, the terminal electrode may be formed by sputtering. In this case, the metal constituting the terminal electrode 91 can be formed on the surfaces of the end portions 12, 13 in an atomically dense manner. Since the surfaces of the end portions 12, 13 are prevented from being exposed to air, the formation of an oxide film on the surfaces of the end portions 12, 13 can also be prevented. This can further improve the reliability of the electrical connection between the terminal electrodes 6, 7 and the conductive wire 9. After the end portions 12, 13 of the conductive wire 9 are formed by plasma treatment without being exposed to air, the terminal electrode 91 can be formed without the surfaces of the formed end portions 12, 13 being exposed to air. In this case, the formation of an oxide film on the surfaces of the end portions 12, 13 can be further prevented.

[0092] In the step of forming the terminal electrode 91, the terminal electrode 91 may be formed by performing electroless plating and then electrolytic plating. In this case, after a metal film is formed on the surfaces of the end portions 12, 13 by the electroless plating process more densely than by the electrolytic plating process, the film formed by the electroless plating process can be thickened by the electrolytic plating process. The speed of forming the terminal electrode 91 can also be further improved. This improves manufacturing throughput and ensures the reliability of the electrical connection between the conductive wire 9 and the terminal electrodes 6, 7. The electroless plating process may include acid treatment of the surfaces of the end portions 12, 13.

[0093] In the example shown in this embodiment, in electronic component 1, ends 12 and 13 of conductive wire 9 protrude from outer surface 10 and extend in a direction intersecting outer surface 10. Terminal electrode 6 covers end 12 and is in contact with end 12. Terminal electrode 7 covers end 13 and is in contact with end 13. In this case, the bonding area between conductive wire 9 and terminal electrode 6 can be secured. Therefore, even if the area of ​​tip surfaces 52a and 53a of conductive wire 9 is not increased, the connection between terminal electrodes 6 and 7 and conductive wire 9 is stronger than when ends 12 and 13 of conductive wire 9 do not protrude from outer surface 10. The bonding strength between terminal electrodes 6 and 7 and conductive wire 9 can be secured. Therefore, the reliability of the electrical connection between terminal electrodes 6 and 7 and conductive wire 9 can be secured while preventing deterioration of characteristics. The conductive wire 9 of electronic component 1 forms coil 15 inside element body 2. Therefore, the reliability of the electrical connection between the terminal electrodes 6, 7 and the conductive wire 9 can be ensured while suppressing a decrease in the inductance of the coil 15.

[0094] The length h of the portion of electronic component 1 where ends 12, 13 protrude from outer surface 10 may be 2 μm or more. In this case, the bonding area between conductive wire 9 and terminal electrodes 6, 7 is more likely to be ensured, and the reliability of the electrical connection can be further improved.

[0095] In electronic component 1, conductive wire 9 includes conductor 21 and insulating coating 22 covering the side surfaces of conductor 21. Side surfaces 52b, 53b of conductor 21 at ends 12, 13 are exposed from insulating coating 22. In this case, insulation between adjacent conductive wires 9 is ensured, and reliability of electrical connection between terminal electrodes 6, 7 and conductive wire 9 can be ensured.

[0096] Here, to explain the above-mentioned effects, examples and comparative examples of the present disclosure will be described using Figures 16(a), 16(b), and 17. Note that the present disclosure is not limited to the following examples. Here, an electronic component having a configuration similar to electronic component 1 and an electronic component as a comparative example were fabricated, and the characteristics related to the electrical resistance value and Q value were confirmed.

[0097] The electronic components of Experimental Examples 2 to 6 were manufactured by the above-described steps S1 to S6. The electronic component of Experimental Example 1 was manufactured by omitting step S4 and performing steps S5 and S6 after the above-described steps S1 to S3.

[0098] In Experimental Examples 1 to 6, the cross section of the conductive wire 64 was circular, the outer diameter of the conductive wire 64 was 34 μm, and the diameter of the conductor of the conductive wire 64 was 25 μm. In step S3, surface polishing was performed at a speed of 100 rpm under a load of 300 g. Tap water was used as the grinding fluid for this surface polishing. In step S5, the terminal electrode 91 was formed by sputtering, where a titanium film was formed to a thickness of 0.05 μm, and then a copper film was formed to a thickness of 5 μm.

[0099] In step S4, the electronic components of Experimental Examples 2 to 5 had the edges 12, 13 formed by water vapor plasma treatment. This water vapor plasma treatment was performed under conditions of an output of 800 W, a flow rate of 20 sccm, and a pressure of 10 Pa. The treatment times for the water vapor plasma treatment for the electronic components of Experimental Examples 2 to 5 were different from each other. The treatment time for Experimental Example 2 was 5 minutes. The treatment time for Experimental Example 3 was 10 minutes. The treatment time for Experimental Example 4 was 20 minutes. The treatment time for Experimental Example 5 was 30 minutes.

[0100] In step S4, the electronic component of Experimental Example 6 had edges 12 and 13 formed by oxygen plasma treatment. This oxygen plasma treatment was performed under conditions of a power output of 500 W, a flow rate of 20 sccm, and a pressure of 10 Pa. In Experimental Example 6, the oxygen plasma treatment was performed for 30 minutes.

[0101] The electronic component of Experimental Example 7 had the same configuration as the electronic components of Experimental Examples 1 to 6, except that it did not have end portions 12, 13 protruding from the outer surface. The electronic component of Experimental Example 7 did not include any portion protruding from the outer surface, and the length of the portion of the end of the conductive wire protruding from the outer surface was 0 μm.

[0102] In Experimental Examples 1 to 7, the electrical resistance between a pair of terminal electrodes was measured. Each terminal electrode was disposed on the outer surface and connected to a conductive wire. Each of the pair of terminal electrodes was connected to a different end of the conductive wire.

[0103] As a result of the measurement, as shown in the table in Fig. 16(a), the electrical resistance value in Experimental Example 1 was 8.084 Ω, and the electrical resistance value in Experimental Example 7 was 454.3 Ω, while the electrical resistance values in Experimental Examples 2 to 6 were 0.141 to 2.047 Ω. Thus, it was confirmed that the electrical resistance values in Experimental Examples 2 to 6 were significantly reduced compared to those in Experimental Examples 1 and 7. Therefore, it was confirmed that when plasma treatment is performed, the electrical resistance value is significantly reduced compared to when plasma treatment is not performed. Also, when plasma treatment is performed and includes the portion where the conductive wire protrudes from the outer surface, it was confirmed that the electrical resistance value is significantly reduced compared to when it does not include the portion where the conductive wire protrudes from the outer surface. In other words, when the ends 12 and 13 are provided, it was confirmed that the electrical resistance value is significantly reduced compared to when the ends 12 and 13 are not provided.

[0104] Furthermore, based on the above measurement results, evaluations were made in five grades of "A", "B", "C", "D", and "E". When the measured electrical resistance value is R, R < 0.15 corresponds to "A", 0.15 ≤ R ≤ 0.6 corresponds to "B", 0.6 < R < 5 corresponds to "C", 5 ≤ R < 100 corresponds to "D", and 100 < R corresponds to "E". When the evaluation is "A", the Q value exceeds 60. When the evaluation is "B", the Q value is 30 or more and 60 or less. When the evaluation is "C", the Q value is less than 30. It can be said that the higher the Q value, the better the characteristics.

[0105] As a result of the evaluation, as shown in the table in Fig. (a), the evaluation in Experimental Example 7 was "E". The evaluation in Experimental Example 1 was "D". The evaluation in Experimental Example 2 was "B". The evaluation in Experimental Example 3 was "B". The evaluation in Experimental Example 4 was "A". The evaluation in Experimental Example 5 was "A". Fig. 16(b) is a graph showing the relationship between the length h of the portion where the end protrudes from the outer surface and the electrical resistance value.

[0106] It was confirmed that, as in Experimental Examples 1 to 5, when the length of the end portion protruding from the outer surface was 2 μm or more, better characteristics were obtained than in the electronic component of Experimental Example 7. Furthermore, when the length of the end portion protruding from the outer surface was 4.75 μm or more, as in Experimental Examples 4 and 5, the evaluation was "A," and it was confirmed that even better characteristics were obtained.

[0107] Furthermore, as shown in the table in FIG. 17, the evaluation of Experimental Example 6 was "C." From the comparison results of Experimental Examples 1, 5, and 6, it was confirmed that when plasma treatment is performed, better characteristics are obtained than when plasma treatment is not performed. Furthermore, it was confirmed that when water vapor plasma treatment is performed, better characteristics are obtained than when oxygen plasma treatment is performed.

[0108] The above describes embodiments and modifications of the present disclosure, but the present disclosure is not necessarily limited to the above-described embodiments and modifications, and various modifications are possible without departing from the spirit of the present disclosure.

[0109] For example, in the above-described embodiment and modified examples, the electronic component 1 is a coil component, and the terminal electrodes 6 and 7 are connected to both ends of the coil 15. However, the electronic component 1 may include a circuit element other than a coil. In this case, the end of the coil 15 may be connected to another circuit element. Therefore, the end 12 and the end 13 do not have to be connected to the end of the same coil. The conductive wire 9 may be a lead wire connected to a circuit element inside the electronic component, rather than forming the coil 15.

[0110] In the above-described embodiment and modified examples, the electronic component 1 includes the core portion 31 disposed inside the coil 15. However, the electronic component 1 does not necessarily have to include the core portion 31. The inside of the coil 15 may be hollow.

[0111] In the above-described embodiment and modified examples, the core portion 31 extends in the width direction D3, which is shorter than the longitudinal direction D1. However, the core portion 31 may extend in the longitudinal direction D1, which is longer than the height direction D2 and the width direction D3.

[0112] In the manufacturing method of electronic component 1 in the above-described embodiment and modified example, molded product 76 in which conductive wire is sealed with resin is formed using winding core 60 provided with coil 15. However, molded product 76 is not limited to being formed using winding core 60. For example, molded product 76 may be formed using a so-called air-core coil.

[0113] In this case, a molded product 76 in which the conductive wire is sealed with resin may be formed by filling a mold in which an air-core coil is placed with resin. The case in which an air-core coil is used will be explained using Figures 18(a) to 19(b). Figures 18(a) and 18(b) show enlarged views of the mold and the coil placed in the mold. Figures 19(a) and 19(b) show enlarged views of the molded product and the coil placed in the mold.

[0114] First, as shown in FIG. 18(a), a plurality of air core coils 15A are arranged in a mold 95. Each air core coil 15A corresponds to a conductive wire. Next, as shown in FIG. 18(b), resin is filled into the mold 95. As a result, as shown in FIG. 19(a), a molded product 76 is formed in which a plurality of air core coils 15A are sealed with resin. In this case as well, the molded product 76 includes a molding surface 76a.

[0115] In a molded product 76 including an air core coil 15A, the air core coil 15A includes connection portions 71a and 71b at both ends of the air core coil 15A. The connection portions 71a and 71b are formed to extend in the radial direction of the coil axis of the air core coil 15A. The connection portions 71a and 71b extend in the same direction. In this case as well, as shown in FIG. 19(b), by removing unnecessary portions, a machined surface 78 perpendicular to the extension direction of the connection portions 71a and 71b is formed. The machined surface 78 is formed, for example, by flat grinding.

[0116] In the above-described embodiment and modified examples, a plurality of coils 15 are formed on one winding core 60. However, only one coil 15 may be formed on one winding core 60. [Explanation of symbols]

[0117] 1...electronic component, 91...terminal electrode, 64...conductive wire, 66, 67...end portion, 15...coil, 21...conductor, 22...insulating coating, 75...resin molded portion, 76...molded product, 86...mask, 89...opening.

Claims

1. preparing a molded product in which a conductive wire is disposed inside a resin molded part molded from resin; irradiating the molding with plasma toward the end of the conductive wire; forming a terminal electrode on the outer surface of the molded resin portion, the terminal electrode being in contact with the end of the conductive wire.

2. The conductive wire includes a conductor and an insulating coating covering a side surface of the conductor, 2. The method for manufacturing an electronic component according to claim 1, wherein in the step of irradiating with plasma, the insulating coating covering the side surface of the conductor at the end is removed by the irradiation with plasma.

3. The method for manufacturing an electronic component according to claim 1 or 2, wherein the plasma is water vapor plasma.

4. The method for manufacturing an electronic component according to claim 1 , wherein the conductive wire forms a coil inside the molded product.

5. The cross-sectional area of ​​the end is 7.85 x 10 －１１ m ２ 1x10 or more －８ m ２ The method for manufacturing an electronic component according to any one of claims 1 to 4, wherein:

6. The method for manufacturing an electronic component according to claim 1 , wherein an area of ​​a joint surface where the conductive wire and the terminal electrode are joined is larger than a cross-sectional area of ​​the end portion.

7. 7. The method for manufacturing an electronic component according to claim 1, wherein in the step of irradiating the plasma, a mask having an opening disposed at a position corresponding to the position of the end is positioned, and the plasma passing through the opening is irradiated onto the molding.

8. The method for manufacturing an electronic component according to claim 1 , wherein in the step of forming the terminal electrodes, the terminal electrodes are formed by sputtering.

9. The method for manufacturing an electronic component according to claim 1 , wherein in the step of forming the terminal electrodes, the terminal electrodes are formed by performing electroless plating and then electrolytic plating.

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