Coil parts

Abstract

To provide a coil component which facilitates manufacture.SOLUTION: A coil component 100 includes: a coil covered with a non-magnetic resin 13; a core 20 which contains a resin mixed with a magnetic body as a main component, and covers at least a part of the coil covered with the non-magnetic resin 13; and a gap 30 which is provided on the core 20, and extends toward the non-magnetic resin 13 from the surface of the core 20. The width of the gap 30 is narrower toward the non-magnetic resin 13 from the surface of the core 20. A tip 30a of the gap 30 extending toward the non-magnetic resin 13 from the surface of the core 20 is separated from the non-magnetic resin 13.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a coil portion Product Regarding. [Background technology]

[0002] Coil components are passive elements that utilize inductance, and in recent years have been installed in various electronic devices as part of circuit elements. For example, inverters installed in vehicles such as electric vehicles, hybrid vehicles, and fuel cell vehicles incorporate converters that step up or step down battery voltage, and coil components are used as key components of these converters.

[0003] As one such coil component, Patent Document 1 discloses a coil component having a coil, a core covering the coil, and a case housing the core, with a resin gap member inside the core made of a material with a lower magnetic permeability than the core. In this coil component, the resin gap member is formed so that the distance that the closed magnetic circuit passes through the resin gap member becomes shorter as it moves away from the coil. Patent Document 1 also discloses that the resin gap member is formed integrally with a resin insulating member that covers the coil winding, and that the coil component is manufactured by housing the coil formed integrally with the resin gap member in a case, and injecting resin mixed with magnetic powder into the case and curing it. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-146753 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the coil component described in Patent Document 1 is not easy to manufacture for the following reasons: When the coil formed integrally with the resin gap member is housed in the case, the resin gap member may collide with the case and be damaged. Also, since the core is formed by injecting resin mixed with magnetic powder into the case while the coil formed integrally with the resin gap member is housed in the case, it is difficult to reliably expose the tip of the resin gap member on the surface of the core.

[0006] The present invention solves the above-mentioned problems and provides a coil section that is easy to manufacture. Product The purpose is to provide. [Means for solving the problem]

[0007] The coil component of the present invention comprises: A coil covered with non-magnetic resin, a core containing, as a main component, a resin mixed with a magnetic material, and covering at least a portion of the coil covered with the non-magnetic resin; a gap provided in the core and extending from a surface of the core toward the nonmagnetic resin; Equipped with the width of the gap narrows from the surface of the core toward the non-magnetic resin, The tip of the gap extending from the surface of the core toward the non-magnetic resin is spaced apart from the non-magnetic resin. [Effects of the Invention]

[0010] In the coil component of the present invention, the core has a gap extending from its surface toward the nonmagnetic resin covering the coil, the width of the gap narrowing as it approaches the nonmagnetic resin from the surface of the core, and the tip of the gap is spaced apart from the nonmagnetic resin. Coil components with such a configuration are easy to manufacture. For example, a coil covered with nonmagnetic resin can be placed in a mold with protrusions, and resin mixed with a magnetic material can be poured into the mold and cured, thereby manufacturing a coil component in which the core and gap are integrally formed. Furthermore, the gap formed by the protrusions on the mold is reliably exposed on the surface of the core. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic perspective view of a coil component according to a first embodiment of the present invention. [Figure 2] FIG. 2(a) is a schematic top view of the coil component, and FIG. 2(b) is a schematic bottom view of the coil component. [Figure 3] FIG. 2 is a schematic front view of the coil component as viewed from the direction in which the conductor wire of the coil is drawn out. [Figure 4] FIG. 2 is a schematic perspective view of a coil. [Figure 5] FIG. 2 is a schematic perspective view of a coil covered with a non-magnetic resin. [Figure 6] FIG. 10 is a schematic front view of a coil component in which a gap is provided between the surface of a non-magnetic resin and the surface of a core that face each other in a direction perpendicular to the direction of the coil winding axis, as viewed from the direction in which the coil conductor wire is pulled out. [Figure 7] 10 is a diagram showing the relationship between the direct current flowing through the coil and the inductance when the distance between the tip of the gap and the non-magnetic resin is different. FIG. [Figure 8] 10 is a flowchart illustrating a method for manufacturing a coil component. [Figure 9] FIG. 2 is a schematic front view of a mold used to form a core. [Figure 10]10(a) to 10(c) are diagrams illustrating a manufacturing process for a coil component in which a core is housed in a case. [Figure 11] FIG. 10 is a schematic front view of a coil component according to a second embodiment, as viewed from the direction in which the conductor wire of the coil is drawn out. [Figure 12] 10 is a schematic bottom view of a coil component in which the gap has an annular shape when the core is viewed in the direction of the winding axis of the coil. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] The features of the present invention will be specifically described below by showing embodiments of the present invention.

[0015] First Embodiment Fig. 1 is a schematic perspective view of a coil device 100 according to a first embodiment of the present invention. Fig. 2(a) is a schematic top view of the coil device 100, and Fig. 2(b) is a schematic bottom view of the coil device 100. Fig. 3 is a schematic front view of the coil device 100 as viewed from the direction in which a conducting wire 11 of a coil 10 (described later) is drawn out.

[0016] The coil component 100 in the first embodiment includes a coil 10 covered with a non-magnetic resin 13, a core 20, and a gap 30.

[0017] Fig. 4 is a schematic perspective view of the coil 10. Fig. 5 is a schematic perspective view of the coil 10 covered with non-magnetic resin 13.

[0018] As shown in Fig. 4, the coil 10 is formed by winding a conductor wire 11. In this embodiment, the conductor wire 11 is wound in a rectangular shape, and when viewed in the direction of the winding axis, the corners of the rectangularly wound conductor wire 11 are rounded. However, the shape of the wound conductor wire 11 is not limited to a rectangular shape, and it may be a circular shape, an elliptical shape, or the like.

[0019] The conductor wire 11 is made of a metal material such as copper, aluminum, or an alloy thereof, and its surface is coated with an enamel material such as polyamideimide or polyimide. The cross-sectional shape of the conductor wire 11 is, for example, circular or flat. In this embodiment, the conductor wire 11 is a rectangular wire with a flat cross-sectional shape and is wound flatwise. However, the rectangular wire conductor 11 may also be wound edgewise. Furthermore, the coil 10 may be wound edgewise or flatwise and also alpha wound. In other words, the present invention is not limited by the material, cross-sectional shape, winding method, etc. of the conductor wire 11.

[0020] The flatwise wound coil 10 is formed by bending the short side (thickness direction) of the cross section of the conductor wire 11, which is a rectangular wire, and winding it into a spiral shape. When the winding axis is oriented vertically, the flatwise wound coil 10 has low thermal conductivity in the horizontal direction of the coil device 100, but good thermal conductivity in the vertical direction.

[0021] In this embodiment, the first lead-out portion 12a and the second lead-out portion 12b, where the conductor wire 11 of the coil 10 is drawn outward, are located at the same height in the direction of the winding axis of the coil 10. Also, in this embodiment, the first lead-out portion 12a and the second lead-out portion 12b of the coil 10 are each drawn out to the short side of the coil 10 around which the conductor wire 11 is wound in a rectangular shape. However, the first lead-out portion 12a and the second lead-out portion 12b of the coil 10 may each be drawn out to the long side of the coil 10.

[0022] As shown in Fig. 5, the coil 10 is covered with a non-magnetic resin 13. In this embodiment, the entire coil 10 except for a portion of the first lead portion 12a and the second lead portion 12b is covered with the non-magnetic resin 13. For example, epoxy resin, silicone resin, polyphenylene sulfide resin, etc. can be used as the non-magnetic resin 13. The thickness of the non-magnetic resin 13 is, for example, 0.1 mm or more and 3 mm or less.

[0023] There is no particular restriction on the molding method for the non-magnetic resin 13, and methods such as injection molding, transfer molding, sheet pressing, etc. can be used. Sheet pressing is a method in which the coil 10 is covered with the non-magnetic resin 13 by sandwiching the coil 10 between multiple laminated non-magnetic resin sheets and applying pressure.

[0024] In this embodiment, the non-magnetic resin 13 contains a filler with high thermal conductivity, such as alumina, etc. With this configuration, the thermal conductivity of the non-magnetic resin 13 is, for example, 1 W / mK or more, and the coil 10 has good heat dissipation properties.

[0025] The core 20 covers at least a portion of the coil 10, which is covered with the non-magnetic resin 13. In this embodiment, as shown in Figs. 1 to 3, the entire coil 10, which is covered with the non-magnetic resin 13, is covered with the core 20 except for the first lead portion 12a and the second lead portion 12b and their surrounding areas.

[0026] The core 20 mainly contains a resin mixed with a magnetic substance (e.g., magnetic powder) made of a soft magnetic metal material or a ferrite material. The main component is the component with the highest content. The soft magnetic metal material is not particularly limited, and examples include various crystalline alloy powder materials such as Fe-Si alloys, Fe-Si-Al alloys, Fe-Si-Cr alloys, Fe-Al alloys, Fe-Ni alloys, and Fe-Co alloys; amorphous materials with excellent soft magnetic properties that contain Fe as the main component; and nanocrystalline metal materials with a mixture of amorphous and nanocrystalline phases. When using such soft magnetic metal materials, it is preferable to form a coating layer made of an insulating material such as phosphate or silicone resin on the surface of the metal powder to ensure insulation.

[0027] The ferrite material is also not particularly limited, and various ferrite materials containing Fe2O3 as the main component, such as Ni-based, Cu-Zn-based, Ni-Zn-based, Mn-Zn-based, and Ni-Cu-Zn-based, can be used.

[0028] The resin contained in the core 20 is, for example, an epoxy resin. However, the resin is not limited to epoxy resin, and other types of resins such as silicone resin and polyphenylene sulfide resin may also be used.

[0029] A gap 30 is provided in the core 20 to suppress magnetic saturation, etc. The gap is sometimes called a magnetic gap. The gap 30 is provided between the opposing surfaces of the non-magnetic resin 13 and the core 20, extending from the surface of the core 20 toward the non-magnetic resin 13. In this embodiment, the gap 30 is provided between the surface of the core 20 and the surface of the non-magnetic resin 13 that face each other in the direction of the winding axis of the coil 10, as shown in FIGS. 1 to 3 .

[0030] Specifically, gaps 30 are provided between a first surface 20a of core 20, which is a surface perpendicular to the winding axis of coil 10, and a first surface 13a of nonmagnetic resin 13, and between a second surface 20b facing first surface 20a of core 20 and a second surface 13b facing first surface 13a of nonmagnetic resin 13. First surface 13a of nonmagnetic resin 13 is located on the first surface 20a side of core 20 and faces first surface 20a of core 20. Second surface 13b of nonmagnetic resin 13 is located on the second surface 20b side of core 20 and faces second surface 20b of core 20.

[0031] The gap 30 is exposed on each of the first surface 20a and the second surface 20b of the core 20. In this embodiment, when the core 20 is viewed in the direction of the winding axis of the coil 10, the gap 30 has a linear shape. That is, as shown in FIG. 2(a), the gap 30 extending linearly parallel to the long sides of the rectangular coil 10 is provided between the first surface 20a of the core 20 and the first surface 13a of the nonmagnetic resin 13. Also, as shown in FIG. 2(b), the gap 30 extending linearly parallel to the long sides of the rectangular coil 10 is provided between the second surface 20b of the core 20 and the second surface 13b of the nonmagnetic resin 13.

[0032] In this embodiment, two gaps 30 are provided between the first surface 20a of the core 20 and the first surface 13a of the nonmagnetic resin 13, and two gaps 30 are provided between the second surface 20b of the core 20 and the second surface 13b of the nonmagnetic resin 13. However, a gap 30 may be provided only either between the first surface 20a of the core 20 and the first surface 13a of the nonmagnetic resin 13, or between the second surface 20b of the core 20 and the second surface 13b of the nonmagnetic resin 13. Also, only one gap 30 may be provided on the first surface 20a side of the core 20, or only one gap 30 may be provided on the second surface 20b side of the core 20.

[0033] 6, the gap 30 may be provided between the surface of the non-magnetic resin 13 and the surface of the core 20 that face each other in a direction perpendicular to the direction of the winding axis of the coil 10.

[0034] 3, a tip end 30a of the gap 30 extending from the surface of the core 20 toward the nonmagnetic resin 13 is separated from the nonmagnetic resin 13. In other words, the gap 30 is not in contact with the nonmagnetic resin 13.

[0035] As shown in FIG. 3 , the width of the gap 30 narrows from the surface of the core 20 toward the nonmagnetic resin 13. That is, the width of the gap 30 is widest at the surface of the core 20 and narrowest at the tip 30a. The width of the gap 30 at the surface of the core 20 is, for example, 1 mm or more and 5 mm or less, and the width of the tip 30a of the gap 30 is, for example, 0.5 mm or more and 3 mm or less. If the distance from the surface of the core 20 is the same, the width of the gap 30 is the same at any position in a direction parallel to the long sides of the coil 10. Note that in this embodiment, the gap 30 extends linearly parallel to the long sides of the coil 10, and therefore the width of the gap 30 refers to the dimension in a direction parallel to the short sides of the coil 10.

[0036] In order to realize a configuration in which the width of gap 30 becomes narrower from the surface of core 20 toward nonmagnetic resin 13, side surfaces 30b of gap 30 are inclined when viewed from a direction perpendicular to the width direction of gap 30, as shown in Fig. 3. Compared to a case in which the side surfaces of gap 30 are not inclined, the gradient of side surfaces 30b of gap 30 is preferably greater than 0° and approximately 3° or less. As shown in Fig. 3, gap 30 has a symmetrical shape in the width direction, and the gradient of a pair of side surfaces 30b of gap 30 is the same.

[0037] Here, in terms of magnetic properties, it is not desirable to provide gap 30 such that gap 30 is not in contact with non-magnetic resin 13 but is separated from it. However, if the separation distance is small, it is possible to keep the decrease in inductance when a direct current is passed through coil 10 within an allowable range.

[0038] FIG. 7 is a diagram showing the relationship between the DC current Idc flowing through the coil 10 and the inductance (L value) when the distance D1 (hereinafter also referred to as the separation distance D1 (see FIG. 3)) between the tip end 30a of the gap 30 and the nonmagnetic resin 13 is different. Here, the relationship between the DC current Idc flowing through the coil 10 and the inductance was investigated when the distance D1 between the tip end 30a of the gap 30 and the nonmagnetic resin 13 was set to 0 mm, 0.001 mm, 0.01 mm, 0.02 mm, 0.03 mm, 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.5 mm, 1 mm, 2 mm, 3.75 mm, and 7.5 mm. Here, the distance D2 (see FIG. 3) between the surface of the core 20 and the nonmagnetic resin 13 in the direction in which the gap 30 extends from the surface of the core 20 was 8 mm.

[0039] Table 1 shows the inductance when the DC current Idc flowing through coil 10 is 0.001 A and the distance D1 between tip 30a of gap 30 and nonmagnetic resin 13 is 0 mm, as a reference inductance. It also shows the allowable range of the distance D1 for inductances that differ by -30%, -20%, -10%, -5%, 5%, 10%, 20%, and 30% from the reference inductance. For example, an inductance that differs by +10% from the reference inductance (86.08 μH) is 94.69 μH, and the allowable distance D1 for this value is 0.05 mm or less. In other words, if the distance D1 between tip 30a of gap 30 and nonmagnetic resin 13 is 0.05 mm or less, the inductance will be 94.69 μH or less, and the variation from the reference inductance will be 10% or less.

[0040] [Table 1]

[0041] Table 2 shows the inductance when the distance D1 between the tip 30a of the gap 30 and the non-magnetic resin 13 is 0 mm when the DC current Idc flowing through the coil 10 is 60 A, and shows the inductance values ​​that differ from the reference inductance by -30%, -20%, -10%, -5%, 5%, 10%, 20%, and 30%, as well as the allowable range of the separation distance D1 at that time.

[0042] [Table 2]

[0043] Table 3 shows the inductance when the distance D1 between the tip 30a of the gap 30 and the non-magnetic resin 13 is 0 mm when the DC current Idc flowing through the coil 10 is 270 A, and shows the inductance values ​​that differ from the reference inductance by -30%, -20%, -10%, -5%, 5%, 10%, 20%, and 30%, as well as the allowable range of the separation distance D1 at that time.

[0044] [Table 3]

[0045] As shown in FIG. 7 and Tables 1 to 3, as the distance D1 between the tip 30a of the gap 30 and the nonmagnetic resin 13 increases, the initial inductance increases, and the amount of inductance decrease on the large current side also increases. As shown in Table 3, when the DC current Idc flowing through the coil 10 is a large current of 270 A, if the distance D1 between the tip 30a of the gap 30 and the nonmagnetic resin 13 is 0.5 mm or less, the decrease in inductance relative to the reference inductance can be kept to within 5%. Therefore, it is preferable that the distance D1 between the tip 30a of the gap 30 and the nonmagnetic resin 13 be greater than 0 mm and 0.5 mm or less.

[0046] However, depending on the size of the coil component 100, even if the separation distance D1 between the tip end 30a of the gap 30 and the non-magnetic resin 13 is 0.5 mm or more, the inductance may not decrease significantly when a DC power source is applied to the coil 10. The inventors have confirmed that if the ratio D1 / D2 of the distance D1 between the tip end 30a of the gap 30 and the non-magnetic resin 13 to the distance D2 between the surface of the core 20 and the non-magnetic resin 13 in the direction in which the gap 30 extends from the surface of the core 20 is 1 / 15 or less, the decrease in inductance when a DC current is superimposed can be suppressed. Therefore, it is preferable that the ratio D1 / D2 be 1 / 15 or less.

[0047] Similar to the core 20, a resin containing a magnetic material is interposed in the separation portion 21 between the tip end 30a of the gap 30 and the non-magnetic resin 13. The content of the magnetic material in the resin interposed in the separation portion 21 is preferably lower than the content of the magnetic material in the resin constituting the core 20 excluding the separation portion 21. For example, when the average particle size of the magnetic material (magnetic powder) contained in the resin used to form the core 20 by molding is larger than the separation distance D1 between the tip end 30a of the gap 30 and the non-magnetic resin 13, the content of the magnetic material in the resin interposed in the separation portion 21 is lower than the content of the magnetic material in the resin constituting the core 20 excluding the separation portion 21. By configuring the resin interposed in the separation portion 21 to have a lower content of the magnetic material than the resin constituting the core 20 excluding the separation portion 21, the magnetic permeability of the separation portion 21 is lower than in a configuration in which the magnetic material contents of both resins are the same, thereby further suppressing a decrease in inductance when a DC current is superimposed. The content means the volume content.

[0048] In this embodiment, the gap 30 is an air gap made of space. However, the gap 30 is not limited to an air gap. For example, the gap 30 may be made of a non-magnetic resin.

[0049] The coil component 100 of this embodiment is easy to manufacture. For example, as described below, it is possible to manufacture the coil component 100 in which the core 20 and the gap 30 are integrally formed by placing the coil 10 covered with the nonmagnetic resin 13 in a mold having protrusions, pouring resin mixed with a magnetic material into the mold, and hardening it. In addition, the gap 30 formed by the mold protrusions is reliably exposed on the surface of the core 20. Furthermore, when forming the gap 30 with the mold protrusions, the protrusions corresponding to the shape of the gap 30 have a shape that tapers from the base to the tip, making it easy to remove the mold.

[0050] (Manufacturing method of coil components) A method for manufacturing the above-described coil device 100 will be described below.

[0051] FIG. 8 is a flowchart illustrating a method for manufacturing the coil device 100.

[0052] In step S1, a coil 10 covered with a non-magnetic resin 13 is prepared as shown in Fig. 5. To this end, the coil 10 is first fabricated by winding a conductor wire 11. In this embodiment, the coil 10 is fabricated by flatwise winding the conductor wire 11 into a rectangular shape as shown in Fig. 4.

[0053] Next, the produced coil 10 is covered with non-magnetic resin 13. For example, the coil 10 is covered with non-magnetic resin 13 by transfer molding. For example, a mold is prepared, the coil 10 is placed in the mold, non-magnetic resin is poured in and hardened, and then the mold is removed to obtain the coil 10 covered with non-magnetic resin 13. For example, a mold having a structure divided into a lower mold and an upper mold is prepared, and the coil 10 is sandwiched between the lower mold and the upper mold.

[0054] In step S2 following step S1, a mold having protrusions corresponding to the shape of the gap 30 is prepared. FIG. 9 is a schematic front view of the prepared mold 40. The mold 40 is composed of an upper mold 40a and a lower mold 40b that can be separated into upper and lower halves. The upper mold 40a and the lower mold 40b each have protrusions 41 corresponding to the shape of the gap 30. "Protrusions 41 corresponding to the shape of the gap 30" means that the shape of the gap 30 and the shape of the protrusions 41 are the same. In this embodiment, the upper mold 40a and the lower mold 40b each have two protrusions 41.

[0055] The protrusions 41 become thinner from the base to the tip, and have a shape that extends linearly parallel to the long sides of the coil 10 when the coil 10 is placed in the mold. The side surfaces 41a of the protrusions 41 are inclined, and the inclination angle is, for example, greater than 0° and not more than 3°. The length of the protrusions 41 is adjusted so that the protrusions 41 do not come into contact with the non-magnetic resin 13 that covers the coil 10 when the coil 10 is placed in the mold 40.

[0056] The process of step S2 may be performed before the process of step S1, or may be performed in parallel with the process of step S1.

[0057] In step S3 following step S2, the coil 10 covered with nonmagnetic resin 13 is placed in the mold 40. In this step, the protrusions 41 of the mold 40 are spaced apart from the nonmagnetic resin 13 covering the coil 10 placed in the mold 40. For example, after the coil 10 covered with nonmagnetic resin 13 is placed in the lower mold 40b, the lower mold 40b is combined with the upper mold 40a and the molds are closed. By closing the mold 40, the coil 10 is positioned within the mold 40. At this time, because the protrusions 41 of the mold 40 are spaced apart from the nonmagnetic resin 13 covering the coil 10, no load stress is applied to the protrusions 41 of the mold 40 or the coil 10 when the mold 40 is closed. Therefore, damage to the protrusions 41 of the mold 40 and the coil 10 when the mold 40 is closed can be suppressed.

[0058] In step S4 following step S3, resin mixed with a magnetic material is poured into the mold 40. This allows the resin to fill the separation portion 21 as well. When a thermosetting resin is used as the resin poured into the mold 40, it is possible to use, for example, an epoxy resin or a phenolic resin, and when a thermoplastic resin is used, it is possible to use, for example, a polyphenylene sulfide resin or a polybutylene terephthalate resin. When a thermosetting resin is used, it is common to perform transfer molding or compression molding, and when a thermoplastic resin is used, it is common to perform injection molding.

[0059] In step S5 following step S4, the resin poured into the mold 40 is hardened. The resin is hardened by heating when a thermosetting resin is used, or by cooling when a thermoplastic resin is used.

[0060] In step S6 following step S5, the mold 40 is removed after the resin has hardened. This forms the core 20 that covers the coil 10 that is covered with the non-magnetic resin 13. The protrusions 41 of the mold 40 become thinner from the base to the tip, making it easier to remove the mold 40 and less likely to be damaged when removing the mold 40. By removing the mold 40, the locations where the protrusions 41 were located become hollow, forming the gaps 30.

[0061] The coil device 100 is manufactured by the above-described manufacturing method.

[0062] After the core 20 is formed, the entire core may be housed in a case. In this case, as shown in Fig. 10(a), the formed core 20 is housed in a case 50. The case 50 is made of a non-magnetic metal material with high thermal conductivity, such as aluminum.

[0063] 10(b), potting resin 60 is injected between the core 20 and the case 50. The potting resin 60 is made of a non-magnetic resin, such as a silicone resin. However, the potting resin 60 is not limited to silicone resin, and epoxy resin, urethane resin, etc. may also be used.

[0064] In this embodiment, the case 50 is provided with an injection port 51 for injecting the potting resin 60, and the potting resin 60 is injected through the injection port 51. The potting resin 60 is injected, for example, to a position that covers the first surface 20a of the core 20. The injected potting resin 60 is then cured.

[0065] In this case, the potting resin 60 fills the air gap formed by the protrusions 41 of the mold 40 to form the gap 30 .

[0066] 10(c), a lid 52 is attached to the case 50 and fixed with screws 53. In this case, the entire assembly including the case 50 becomes the coil device 100 as shown in FIG. 10(c).

[0067] The manufacturing method of the coil component according to the present embodiment facilitates manufacturing compared to conventional manufacturing methods in which a gap is formed when the coil is covered with nonmagnetic resin. Specifically, in conventional manufacturing methods in which a gap is formed when the coil is covered with nonmagnetic resin, the gap may be damaged when the coil, which is integrally formed with the gap, is placed in a case for forming the core. In contrast, the manufacturing method of the coil component according to the present embodiment integrally forms the core 20 and the gap 30, eliminating such damage. Furthermore, since the gap 30 is formed by the protrusion 41 of the mold 40, the gap 30 can be reliably exposed on the surface of the core 20. Furthermore, since the tip of the protrusion 41 of the mold 40 is spaced from the nonmagnetic resin 13 during the process of placing the coil 10, damage caused by contact between the nonmagnetic resin 13 and the protrusion 41 of the mold 40 is suppressed. Furthermore, since the protrusion 41 of the mold 40 tapers from its base to its tip, the mold 40 is easily removed, and damage to the protrusion 41 is suppressed.

[0068] <Second embodiment> FIG. 11 is a schematic front view of a coil device 100A according to the second embodiment, as viewed from the direction in which the conducting wire 11 of the coil 10 is drawn out.

[0069] In the coil device 100 according to the first embodiment, the tip end 30 a of the gap 30 extending from the surface of the core 20 toward the nonmagnetic resin 13 is spaced apart from the nonmagnetic resin 13 .

[0070] In contrast, the coil device 100A of the second embodiment has a configuration in which the coil device 100 of the first embodiment further includes an elastic member 70 disposed in the separation portion 21 thereof so as to be sandwiched between the tip end portion 30a of the gap 30 and the non-magnetic resin 13. The width of the gap 30 becomes narrower from the surface of the core 20 toward the elastic member 70.

[0071] The elastic member 70 is a non-magnetic material having a lower elastic modulus than the non-magnetic resin 13 that covers the coil 10. The elastic modulus of the elastic member 70 is, for example, 1 GPa or less. As shown in FIG. 11 , the elastic member 70 is in contact with both the gap 30 and the non-magnetic resin 13. The elastic member 70 is made of, for example, any one of silicone resin, Teflon (registered trademark) resin, fluororesin, epoxy resin, and urethane resin. Since the interior of the mold 40 is exposed to high temperatures when molding the core 20, it is preferable that the elastic member 70 have excellent heat resistance. Examples of materials for the elastic member 70 that have excellent heat resistance include silicone resin, Teflon (registered trademark) resin, and fluororesin. However, the elastic member 70 is not limited to resin.

[0072] The elastic member 70 may be of a type in which a liquid material is applied and hardened, or of a type in which a tape-like solid material is attached.

[0073] In this embodiment, similar to the gap 30, two elastic members 70 extending linearly in parallel to the long sides of the rectangular coil 10 are provided on the first surface 13a of the non-magnetic resin 13. In addition, two elastic members 70 extending linearly in parallel to the long sides of the rectangular coil 10 are provided on the second surface 13b of the non-magnetic resin 13.

[0074] The elastic member 70 is a non-magnetic material and is disposed so as to be sandwiched between the gap 30 and the non-magnetic resin 13, and therefore also functions as a gap. Therefore, the coil device 100A of the second embodiment can further suppress the decrease in inductance when a direct current is superimposed, compared to the coil device 100 of the first embodiment in which a magnetic material is present between the gap 30 and the non-magnetic resin 13.

[0075] Coil component 100A of the second embodiment can be manufactured by the same manufacturing method as coil component 100 of the first embodiment. In addition to the manufacturing process of coil component 100 of the first embodiment, the manufacturing method of coil component 100A of the second embodiment further includes, before the step of arranging coil 10 (step S3 in FIG. 8 ), a step of arranging elastic member 70 having a lower elastic modulus than nonmagnetic resin 13 on the surface of nonmagnetic resin 13 at a position that faces protrusion 41 of mold 40 when coil 10 is arranged. As a result, when coil 10 covered with nonmagnetic resin 13 is arranged in mold 40, protrusion 41 of mold 40 abuts on elastic member 70, so that no load is applied to either mold 40 or nonmagnetic resin 13, and resin leakage at the mold mating surfaces can be suppressed.

[0076] The present invention is not limited to the above-described embodiment, and various applications and modifications can be made within the scope of the present invention. For example, as shown in Fig. 12, when the core 20 is viewed in the direction of the winding axis of the coil 10, the gap 30 may have an annular shape. While Fig. 12 shows the second surface 20b side of the core 20, the first surface 20a side is similar. <Additional Notes> The technical ideas that can be understood from the above-described embodiment and modified examples will be described. [1] A coil covered with non-magnetic resin, a core containing, as a main component, a resin mixed with a magnetic material, and covering at least a portion of the coil covered with the non-magnetic resin; a gap provided in the core and extending from a surface of the core toward the nonmagnetic resin; an elastic member having a lower elastic modulus than the non-magnetic resin, the elastic member being disposed between the non-magnetic resin and a tip end of the gap extending from a surface of the core toward the non-magnetic resin; The coil component is characterized in that the width of the gap becomes narrower from the surface of the core toward the elastic member. [2] A method for manufacturing a coil component including: a coil covered with a non-magnetic resin; a core containing, as a main component, a resin mixed with a magnetic material and covering at least a portion of the coil covered with the non-magnetic resin; and a gap provided in the core and extending from a surface of the core toward the non-magnetic resin, preparing the coil covered with the non-magnetic resin; preparing a mold having a protrusion corresponding to the shape of the gap; placing the coil covered with the non-magnetic resin in the mold; pouring the resin mixed with the magnetic material into the mold; curing the resin poured into the mold; and removing the mold after the resin has hardened. The protrusion of the mold becomes thinner from the base to the tip, A method for manufacturing a coil component, characterized in that, in the process of placing the coil, the tip of the protrusion and the non-magnetic resin covering the coil placed in the mold are spaced apart. [Explanation of symbols]

[0077] 10 coils 11 Conductor 12a First drawer 12b Second drawer 13 Non-magnetic resin 20 cores 21 Separation part 30 Gap 40 mold 41 Protrusion 50 cases 60 Potting Resin 70 Elastic member 100, 100A coil parts

Claims

1. A coil covered with non-magnetic resin, a core containing, as a main component, a resin mixed with a magnetic material, and covering at least a portion of the coil covered with the non-magnetic resin; a gap provided in the core and extending from a surface of the core toward the non-magnetic resin; the width of the gap narrows from the surface of the core toward the non-magnetic resin, a tip end of the gap extending from a surface of the core toward the non-magnetic resin is spaced apart from the non-magnetic resin; a resin containing a magnetic material is interposed in a space between the tip of the gap and the non-magnetic resin, A coil component characterized in that the content of the magnetic material in the resin interposed in the separation portion is lower than the content of the magnetic material in the resin constituting the core excluding the separation portion.

2. 2. The coil component according to claim 1, wherein the distance between the tip of the gap and the non-magnetic resin is greater than 0 mm and equal to or less than 0.5 mm.

3. 3. The coil component according to claim 1, wherein a ratio D1 / D2 of a distance D1 between a tip end of the gap and the non-magnetic resin to a distance D2 between the surface of the core and the non-magnetic resin in a direction in which the gap extends from the surface of the core is 1 / 15 or less.

4. The coil component according to any one of claims 1 to 3, characterized in that the gap is provided between opposing surfaces of the core and the non-magnetic resin in the direction of the winding axis of the coil.

5. 5. The coil component according to claim 4, wherein the gap has a linear shape when the core is viewed in the direction of the winding axis of the coil.

6. 5. The coil component according to claim 4, wherein the gap has an annular shape when the core is viewed in the direction of the winding axis of the coil.

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