Inductor, core set, and inductor manufacturing method

Abstract

A gap material (40) is disposed between a first core (10) and a second core (20), and separates the first core (10) and the second core (20) from each other. An adhesive (50) is applied between the first core (10) and the second core (20). Both ends of a conductor (30) extend out from a groove (11), and are respectively arranged along first and second opposing lateral surfaces of the first core (10). The distance between the first lateral surface and the adhesive (50) when viewed in the extending direction of the groove (11) is equal to or less than that between the second lateral surface and the adhesive (50). The gap material (40) is disposed between the adhesive (50) and the first lateral surface when viewed in the extending direction of the groove (11).

Description

Technical Field

[0001] The present invention relates to an inductor, a core set constituting such an inductor, and a method for manufacturing such an inductor.

Background Art

[0002] Some inductors have a structure where a conductor is surrounded by a plurality of magnetic cores, and a gap is provided between the magnetic cores by arranging a gap material between the magnetic cores. Specifically, there is an inductor in which a conductor is fitted into a concave groove formed on the upper surface of a U-shaped core or an E-shaped core, a gap material is arranged on this upper surface, and an I-shaped core is further arranged so as to sandwich the gap material between the U-shaped core or the E-shaped core. The U-shaped core or the E-shaped core is adhered to the I-shaped core with an adhesive or the like.

[0003] Regarding this type of technology, Patent Document 1 discloses the following inductor. A conductor (2) is arranged so as to be fitted into a central groove of a U-shaped magnetic core (1b). The conductor (2) is integrally formed with a gap material (6), and the gap material (6) is provided at a middle portion in the length direction of the extension of the conductor (2) and is formed so as to be orthogonal to the conductor (2). An adhesive (4) is applied to the four corners of the upper surface of the U-shaped magnetic core (1b) where the groove is provided. That is, the gap material (6) is arranged inside the extension direction of the conductor (2) as viewed from the adhesive (4). The I-shaped magnetic core (1a) is placed on the upper side of the U-shaped magnetic core (1b), and by being pressurized and heat-cured, the I-shaped magnetic core (1a), the U-shaped magnetic core (1b), and the gap material (6) are fixed respectively. Both ends of the conductor (2) extend out of the groove and are bent along the outer surface of the U-shaped magnetic core (1b) to form mounting terminals. Specifically, both ends of the conductor (2) are each bent twice to form mounting terminals having a standing portion along the side surface of the U-shaped magnetic core (1b) and a flat portion along the lower surface of the U-shaped magnetic core (1b).

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2010-177614 [Overview of the project] [Problems that the invention aims to solve]

[0005] Generally, inductors are joined to the mounting substrate by a conductive bonding agent such as solder. When the mounting terminal has an upright portion and a flat portion, as in the inductor described in Patent Document 1, in addition to the opposing flat portion and the mounting substrate being soldered together, the solder also rises and extends along the upright portion that runs along the side of the inductor, forming a triangular prism-shaped (triangular in side view) solder fillet between it and the mounting substrate. Here, it is preferable that the surface of the inductor's mounting terminal has good solder wettability. This is because when the mounting terminal and the mounting substrate are soldered together, the solder rises and extends sufficiently along the upright portion of the mounting terminal, forming a solder fillet of the desired size and shape. When the solder fillet is well formed, the bond between the mounting terminal and the mounting substrate becomes strong, and the conductivity between the mounting terminal and the mounting substrate also becomes good. When an inductor is constructed as described in Patent Document 1, when an I-shaped magnetic core (1a) is placed on a U-shaped magnetic core (1b), the adhesive (4) is crushed and spread out as it is sandwiched between the U-shaped magnetic core (1b) and the I-shaped magnetic core (1a), potentially leaking out of the inductor and adhering to the mounting terminals. If adhesive (4) adheres to the mounting terminals, the solder wettability of the mounting terminal surface deteriorates, leading to a problem of faulty soldering between the mounting terminals and the mounting substrate. This type of problem is not limited to solder, but can occur in brazing in general using other metal brazing materials.

[0006] This invention has been made in view of the above-mentioned problems, and provides an inductor with good wettability of the terminal surface. [Means for solving the problem]

[0007] The inductor of the present invention comprises a first core which is a magnetic material having a groove on its upper surface, a conductor which is fitted into the groove, a second core which is a magnetic material which is combined with the first core so as to cover the groove, a gap material which is disposed between the first core and the second core to separate the first core and the second core, and an adhesive which is applied between the first core and the second core, wherein both ends of the conductor extend from the groove and are arranged along the first and second opposing sides of the first core, respectively, and the distance between the first side and the adhesive in the direction in which the groove extends is equal to or less than the distance between the second side and the adhesive. The first core has third and fourth sides arranged in an orthogonal direction perpendicular to the extending direction and facing each other, and the gap material is positioned laterally between the adhesive and the first side when viewed in the extending direction, between the adhesive and the second side when viewed in the extending direction, and between the adhesive and the third side of the third and fourth sides that is close to the adhesive when viewed in the orthogonal direction, and surrounds the adhesive in three directions in a continuous manner, the gap material is not positioned in the region on the groove side of the adhesive, and the surrounding region, which is the region surrounded by the gap material, is connected to the groove. It is characterized by the following:

[0008] The core set of the present invention comprises a first core which is a magnetic material having grooves on its upper surface, a second core which is a magnetic material used in combination with the first core so as to cover the grooves, and a gap material disposed on the upper surface of the first core, wherein the gap material is disposed on the upper surface on both sides in the direction of extension of the grooves. The gap material, which is positioned on both sides in the extending direction, is connected on the opposite side of the groove in a direction perpendicular to the extending direction, and surrounds at least three sides of a portion of the upper surface, and the gap material is not positioned in the region closer to the groove than the portion of the surface, and the portion of the surface is connected to the groove. It is characterized by the following:

[0009] The present invention relates to a method for manufacturing an inductor, comprising: a first core having a groove on its upper surface; a conductor fitted into the groove; a second core combined with the first core so as to cover the groove; a gap material sandwiched between the first core and the second core to separate them; and an adhesive for joining the first core and the second core, wherein the method for manufacturing an inductor comprises: an arrangement step of arranging an insulating material on the first core so as to cover the upper surface; and regions of the insulating material on both sides in the direction of extension of the groove. and the region connecting the two sides on the opposite side of the groove in the direction perpendicular to the extending direction. The process includes: a cutting step in which the gap material is cut out; a removal step in which the portion of the insulating material excluding the gap material is removed; and a joining step in which the adhesive is applied to the position corresponding to the removed portion to join the first core and the second core. Furthermore, the gap material cut out by the cutting process surrounds at least three sides of a portion of the upper surface, is not positioned in the area closer to the groove than the portion, the portion is connected to the groove, and in the joining process, the adhesive is applied to the portion. .

[0010] The adhesive, which is sandwiched between the first and second cores and tends to spread in the direction of the conductor's extension, is blocked by the gap material. This prevents the adhesive from leaking out onto the sides of the first core along both ends of the conductor, and maintains good wettability of the mounting terminal surface. [Effects of the Invention]

[0011] According to the present invention, the inductor, core set, and inductor manufacturing method can provide an inductor with good wettability of the terminal surface. [Brief explanation of the drawing]

[0012] The aforementioned objectives, as well as other objectives, features, and advantages, will become even clearer from the preferred embodiments described below and the accompanying drawings.

[0013] [Figure 1] This is a perspective view showing an example of an inductor according to the first embodiment of the present invention. [Figure 2] This is a top view of the inductor according to the first embodiment (however, the second core is not shown). [Figure 3] This is a front view of the inductor according to the first embodiment. [Figure 4] This is a bottom view of the inductor according to the first embodiment. [Figure 5] This is a longitudinal cross-sectional view of the inductor according to the first embodiment, taken in the direction of the arrow VV, along the dashed line shown in Figure 3. [Figure 6] This is a top view of the first core in the cutting process in the manufacturing method of an inductor according to the first embodiment. [Figure 7] (a) and (b) are examples of top views of an inductor in which the first core has two grooves (the second core is not shown). [Modes for carrying out the invention]

[0014] Each of the various components of the inductor of the present invention does not necessarily exist independently. It is acceptable that a plurality of components are formed as a single member, that one component is formed of a plurality of members, that a certain component is part of another component, that a part of a certain component overlaps with a part of another component, and the like. Further, when the method for manufacturing the inductor of the present invention is described using a plurality of steps described in order, the order of the description does not limit the order or timing of executing the plurality of steps. Therefore, when implementing the method for manufacturing the inductor of the present invention, the order of the plurality of steps can be changed within a range that does not cause any problem in terms of content, and a part or all of the execution timings of the plurality of steps may overlap with each other.

[0015] Hereinafter, embodiments of the present invention will be described based on the drawings. In each of the drawings, corresponding components are denoted by common reference numerals, and redundant descriptions will be omitted as appropriate. In the present embodiment, the directions of front and rear, left and right, up and down are defined as shown in each figure for explanation. However, this is defined for convenience in order to simply explain the relative relationship of the components, and does not limit the directions during the manufacturing or use of the product implementing the present invention. Also, the up and down directions may be referred to as the vertical direction. Further, the direction orthogonal to the vertical direction may be referred to as the horizontal direction. The direction orthogonal to the extending direction of the conductor (left and right direction) may be referred to as the width direction. The plane referred to in the present invention means a physically formed shape aimed at a plane, and of course, it does not necessarily have to be a geometrically perfect plane.

[0016] Hereinafter, it will be described that the terminal portion 33 and the mounting substrate are joined by solder, but the present invention is not limited thereto. Not only solder, but the terminal portion 33 and the mounting substrate may be joined by other metal brazes.

[0017] <First Embodiment> (Inductor) The inductor 100 of the first embodiment will be described using FIGS. 1 to 5.

[0018] First, an overview of the inductor 100 in this embodiment will be described. The inductor 100 comprises a first core 10, a conductor 30, a second core 20, a gap material 40, and an adhesive 50. The first core 10 is a magnetic material having a groove 11 on its upper surface 10a. The conductor 30 is positioned to fit into the groove 11. The second core 20 is a magnetic material that is combined with the first core 10 so as to cover the groove 11. The gap material 40 is positioned between the first core 10 and the second core 20 to separate them. The adhesive 50 is applied between the first core 10 and the second core 20. Both ends of the conductor 30 extend from the groove 11 and are positioned along the first and second opposing sides (front 10c and back 10d) of the first core 10, respectively. When viewed in the extending direction (front-to-back direction) of the groove 11, the distance between the first side surface (front 10c or back 10d) and the adhesive 50 is equal to or less than the distance between the second side surface (back 10d or front 10c) and the adhesive 50. The gap material 40 is positioned between the adhesive 50 and the first side surface (front 10c or back 10d) when viewed in the extending direction of the groove 11.

[0019] Next, the inductor 100 of this embodiment will be described in detail. The first core 10 and the second core 20 together form a closed magnetic circuit around the conductor 30. The first core 10 and the second core 20 are integrally molded from a magnetic material such as ferrite. In this embodiment, as shown in Figure 1, the first core 10 and the second core 20 are roughly rectangular in shape, and together they form a roughly cubic shape. The first core 10 and the second core 20 each have an upward-facing top surface (10a, 20a), a downward-facing bottom surface (10b, 20b), a forward-facing front surface (10c, 20c), a backward-facing back surface (10d, 20d), a left-facing left surface (10e, 20e), and a right-facing right surface (10f, 20f). Furthermore, the top surface (10a, 20a) and the bottom surface (10b, 20b), the front surface (10c, 20c) and the back surface (10d, 20d), and the left surface (10e, 20e) and the right surface (10f, 20f) each face each other. The first core 10 and the second core 20 have a flattened shape overall, with the top and bottom surfaces being larger than the front, back, left, and right surfaces, respectively. The shapes of the first core 10 and the second core 20 are not limited to rectangular parallelepipeds; for example, they may be prisms with a polygonal base. The faces constituting the first core 10 and the second core 20 do not need to be perfectly flat; they may be curved or distorted.

[0020] The groove 11 is a recessed portion formed in the upper surface 10a of the first core 10 for the conductor 30 to be fitted into. The groove 11 is formed as a long groove recessed from front to back on the upper surface 10a of the first core 10. The groove 11 may be formed in a straight line or in a curved shape. In this embodiment, the first core 10 is shown as a U-core with one groove 11 formed on its upper surface 10a, but multiple grooves 11 may be formed on the upper surface 10a. For example, the first core 10 may be an E-core with two grooves 11 formed side by side on its upper surface 10a. Also, in this embodiment, the groove 11 is located in the center of the width direction of the upper surface 10a, but it may be located to the left or right of the center in the width direction. The depth of the groove 11 is greater than or equal to the thickness of the fitting portion 31 of the conductor 30, which will be described later. The depth of the groove 11 and the thickness of the fitting portion 31 of the conductor 30 may be approximately the same, and the upper surface 31a of the fitting portion 31 of the conductor 30 and the upper surface 10a of the first core 10 may be at the same height. The width (length in the width direction) of the groove 11 is greater than or equal to the width of the fitting portion 31 of the conductor 30. In this embodiment, the width of the groove 11 is greater than the width of the conductor 30. Also, as shown in Figure 3, the conductor 30 is positioned in the center of the groove 11 in the width direction, and a gap is created between the conductor 30 and the groove 11 on both sides of the conductor 30 in the left-right direction.

[0021] Here, "the second core 20 is combined with the first core 10 so as to cover the groove 11" means that the second core 20 is placed on top of the first core 10 such that, when viewed from above, substantially the entire groove 11 overlaps with the second core 20. More specifically, it means that the lower surface 20b of the second core 20 overlaps with the groove 11. It is not necessary for a part of the groove 11 to overlap with the second core 20. In this embodiment, the second core 20 has a shape and dimensions that can cover substantially the entire upper surface 10a of the first core 10, including the groove 11, and is placed so as to overlap with the first core 10 when viewed from above. Specifically, the shape and dimensions of the upper surface 10a of the first core 10 and the shape and dimensions of the lower surface 20b of the second core 20 are substantially the same. Furthermore, the second core 20 is placed on top of the first core 10 so that the front surfaces (10c, 20c), back surfaces (10d, 20d), left surfaces (10e, 20e), and right surfaces (10f, 20f) of the first core 10 and the second core 20 are on the same plane without any steps, and are flush with the surface.

[0022] The conductor 30 is a component through which electric current is passed, and is made of a conductive material such as metal. In this embodiment, the conductor 30 is generally a long, plate-shaped component. As shown in Figure 5, the conductor 30 is arranged along the outer surface of the first core 10. Specifically, the middle portion of the conductor 30 is fitted into the groove 11 of the first core 10 as a fitting portion 31. Both sides of the fitting portion 31 extend from the groove 11, and the portions extending from the groove 11 are bent relative to the fitting portion 31 and are arranged along the front surface 10c and back surface 10d of the first core 10. Here, the portion of the conductor 30 arranged on the front surface 10c and back surface 10d of the first core 10 is called the outer surface arrangement portion 32. In this embodiment, the entire external surface arrangement portion 32 is located outside the front surface 10c or back surface 10d of the first core 10. Alternatively, the portion of the front surface 10c and back surface 10d of the first core 10 to which the external surface arrangement portion 32 extends may be formed as a recess, so that part or all of the external surface arrangement portion 32 is located within the envelope volume of the first core 10.

[0023] Both ends of the conductor 30 are positioned as terminal portions 33 on terminal arrangement portions 14 provided on the lower surface 10b of the first core 10, and are approximately parallel to the lower surface 10b of the first core 10. That is, the conductor 30 positioned along the front surface 10c or back surface 10d is bent towards the lower surface 10b near the boundary between the front surface 10c or back surface 10d and the lower surface 10b. The terminal portion 33 is the part of the conductive material 30 that is joined to the mounting board by soldering or the like. The terminal arrangement portion 14 is the area on the lower surface 10b of the first core 10 where the terminal portion 33 of the conductor 30 is arranged. In this embodiment, it is formed as an upwardly concave recess on the lower surface 10b of the first core 10. As shown in Figure 4, the width of the terminal arrangement portion 14 is greater than or equal to the width of the terminal portion 33, and the length of the terminal arrangement portion 14 in the front-rear direction is greater than or equal to the length of the terminal portion 33 in the front-rear direction. As shown in Figure 5, the depth of the recess in the terminal arrangement section 14 (the length from the bottom of the recess to the bottom of the recess relative to the bottom surface 10b) is smaller in areas closer to the periphery of the bottom surface 10b and larger in areas closer to the center of the bottom surface. In other words, the bottom of the recess in the terminal arrangement section 14 is formed in a sloping shape that deepens towards the center of the bottom surface 10b. As will be explained later in the manufacturing method of the inductor 100, the conductor 30 is arranged around the first core 10 in a bent state. By deepening the central side of the lower surface 10b at the bottom of the terminal arrangement section 14, the terminal portion 33 of the conductor 30 can be positioned in a sufficiently bent state so that it bites into the terminal arrangement section 14. In other words, the angle between the terminal portion 33 and the outer arrangement section 32 can be bent to less than 90 degrees. This prevents the terminal portion 33 from floating relative to the mounting substrate due to insufficient bending of the terminal portion 33 and the outer arrangement section 32. Furthermore, in this embodiment, the depth of the shallowest part of the bottom of the recess in the terminal arrangement section 14 is less than the thickness of the terminal section 33. As a result, a portion of the terminal section 33 is located within the recess of the terminal arrangement section 14, while another portion of the terminal section 33 protrudes below the lower surface 10b of the first core 10 (towards the mounting substrate). This ensures good contact with the mounting substrate.

[0024] As shown in Figure 5, it is preferable that the corners that form the boundary between the groove 11 and the front surface 10c, and between the groove 11 and the back surface 10d (the corners of the first core 10 if chamfering is not performed) are chamfered to form the upper chamfered shape portion 12. It is also preferable that the corners that form the boundary between the terminal arrangement portion 14 and the front surface 10c, and between the terminal arrangement portion 14 and the back surface 10d are chamfered to form the lower chamfered shape portion 13. In this embodiment, the upper chamfered portion 12 and the lower chamfered portion 13 are formed as a single-step stepped chamfered shape. That is, they are composed of an inclined surface that slopes downward from the upper surface 10a or upward from the lower surface 10b, and a surface parallel to the upper surface 10a or the lower surface 10b. The shape of the upper chamfered portion 12 and the lower chamfered portion 13 is not limited to the stepped shape described above. For example, the upper chamfered portion 12 and the lower chamfered portion 13 may be a C-chamfered shape or an R-chamfered shape. By chamfering the corners at the bending points of the conductor 30 in the first core 10, the first core 10 and the conductor 30 do not interfere with each other, thereby preventing wear on both the first core 10 and the conductor 30. Furthermore, the bent portion of the conductor 30 may be angular or arc-shaped (R-shaped). If the bent portion of the conductor 30 is arc-shaped, as in this embodiment, the corners of the position where the conductor 30 bends in the first core 10 can be chamfered, allowing the side surface and groove 11 of the first core 10 to come into contact with the conductor 30 over substantially its entire length.

[0025] As shown in Figure 3, the gap material 40 is a member that separates the upper surface 10a of the first core 10 and the lower surface 20b of the second core 20. In other words, the gap material 40 separates the first core 10 and the second core 20 such that the distance between them is equal to the thickness of the gap material 40. The gap material 40 is made by cutting the insulating material 60 into a desired shape. The insulating material 60 contains an insulating material such as resin and is formed in the form of a thin, substantially uniform thickness sheet. By using insulating material 60 of a predetermined thickness, the gap between the upper surface 10a of the first core 10 and the lower surface 20b of the second core 20 can be adjusted to obtain a desired inductance value. The insulating material 60 may be constructed by laminating a base layer and an adhesive layer. For example, in the inductor manufacturing method described later, if the gap material 40 is placed on the upper surface 10a of the first core 10 so that the adhesive layer faces the first core 10, it is possible to prevent the gap material 40 from shifting on the upper surface 10a of the first core 10. For example, a tape in which an adhesive layer is coated on an insulating resin layer such as polyimide may be used as the insulating material 60. Alternatively, a tape in which adhesive layers are laminated on both sides of a base layer may be used as the insulating material 60. In other words, the gap material 40 and the first core 10 or the second core 20 may be bonded together via the adhesive layer. The first core 10 and the second core 20 may be bonded together via the gap material 40, and the adhesive 50 may be used to assist in the joining of the first core 10 and the second core 20. In this embodiment, the gap material 40 is placed on the upper surface 10a of the first core 10, and the second core 20 is placed on top of the gap material 40 sandwiched between the first core 10 and the gap material 40. However, the present invention is not limited to this. The gap material 40 may be placed on the lower surface 20b of the second core 20, and the first core 10 may be placed on the side of the gap material 40 (lower side) of the second core 20.

[0026] The adhesive 50 is a material used to join the first core 10 and the second core 20. In other words, the first core 10 and the second core 20 are joined together by the adhesive 50 without separating. As the adhesive 50, adhesive resins such as epoxy resin, phenolic resin, and acrylic resin can be used. The adhesive 50 only needs to be applied in contact with the first core 10 and the second core 20, and it may be applied to either the first core 10 or the second core 20 during the manufacturing process. That is, the adhesive 50 may be applied to the first core 10 and the second core 20 may be assembled to the side to which the adhesive 50 is applied, or the adhesive 50 may be applied to the second core 20 and the first core 10 may be assembled to the side to which the adhesive 50 is applied. It is preferable to apply the adhesive 50 to the upper surface 10a of the first core 10 or the lower surface 20b of the second core 20, where the gap material 40 is not placed. The adhesive 50 tries to spread thinly between the first core 10 and the second core 20, but even when it spreads thinly, it still maintains a certain thickness. By applying the adhesive 50 to the first core 10 or the second core 20 while avoiding the gap material 40, the distance between the first core 10 and the second core 20 can be controlled regardless of the thickness of the adhesive 50. Specifically, the distance between the first core 10 and the second core 20 can be set to the thickness of the gap material 40.

[0027] Here, the first side and the second side refer to either of the pair of surfaces (in this embodiment, the front surface 10c and the back surface 10d) of the first core 10 along which the conductor 30 is arranged. The distance between the adhesive 50 and the first side is equal to or shorter than the distance between the adhesive 50 and the second side. That is, of the front surface 10c and the back surface 10d, the one that is closer to or equal to the distance from the adhesive 50 is the first side, and the other is the second side. For example, if the adhesive 50 is applied to the area on the top surface 10a on the front surface 10c side from the center in the front-to-back direction, the first side is the front surface 10c and the second side is the back surface 10d. If the adhesive 50 is applied to the area on the top surface 10a on the back surface 10d side from the center in the front-to-back direction, the first side is the back surface 10d and the second side is the front surface 10c. Furthermore, if the adhesive 50 is applied to the center in the front-to-back direction on the upper surface 10a, either the front surface 10c or the back surface 10d becomes the first side surface, and the other becomes the second side surface. In this embodiment, since the adhesive 50 is applied to the center in the front-to-back direction on the upper surface 10a, the first side will be described below as the front surface 10c and the second side as the back surface 10d, but the first side may be the back surface 10d and the second side as the front surface 10c.

[0028] Furthermore, the first and second sides are defined for each application position of the adhesive 50. In this embodiment, adhesive 50 (50a, 50b) is applied to one location each in the left and right regions on either side of the groove 11 on the upper surface 10a, and the application positions of the adhesive 50 are the same distance from the front surface 10c and the back surface 10d in the front-rear direction. For this reason, the adhesive 50a applied to the left region and the adhesive 50b applied to the right region may both have the front surface 10c as their first side and the back surface as their second side. For example, if the adhesive 50a in the left region is applied to the front surface 10c side and the adhesive 50b in the right region is applied to the back surface 10d side, then the first side for the adhesive 50a in the left region is the front surface 10c, and the first side for the adhesive 50b in the right region is the back surface 10d.

[0029] As shown in Figure 2, the gap material 40 is positioned in the region (first region 10g) between the adhesive 50 and the first side surface of the adhesive 50 when viewed in the front-to-back direction. When the inductor 100 is viewed from above, the gap material 40 is positioned in the region (first region 10g) sandwiched between the adhesive 50 and the first side surface in the front-to-back direction. Here, the adhesive 50 sandwiching the gap material 40 in the front-to-back direction along with the first side surface refers to the main volume portion of the applied adhesive. That is, it refers to the area where the adhesive 50 is dripped onto the first core 10 or the second core 20. Here, for example, during the manufacturing process of the inductor 100, when the adhesive 50 is dripped onto the upper surface 10a of the first core 10, some of the adhesive 50 may unexpectedly splatter. Also, some of the adhesive 50 that is sandwiched between the first core 10 and the second core 20 and tries to spread laterally may overflow the gap material 40 and unexpectedly enter the space between the gap material 40 and the second core 20. In these cases, the adhesive 50 in the sense of "the gap material 40 being positioned between the adhesive 50 and the first side surface when viewed in the front-to-back direction" refers to the main volume portion of the adhesive 50 that was intentionally applied, and does not include any adhesive 50 that has unexpectedly splattered or adhesive 50 that has unexpectedly gotten onto the gap material 40. In this embodiment shown in Figure 2, the upright end face of the gap material 40 is positioned between the first side surface (front surface 10c) and the approximately circular main volume portion of the adhesive 50 (e.g., adhesive 50b) applied on the upper surface 10a of the first core 10, when viewed in the front-to-back direction (forward). In this embodiment, adhesive 50 is applied to two locations on the upper surface 10a (one on each side of the groove 11), and a gap material 40 is placed between each of the two locations where adhesive 50 is applied and the first side surface corresponding to each adhesive 50, but this is not limited to this. It is sufficient that a gap material 40 is placed between the adhesive 50 and the first side surface for at least one of the adhesives 50 applied on the upper surface 10a. Preferably, a gap material 40 is placed between each adhesive 50 and the first side surface corresponding to all of the adhesives 50 applied on the upper surface 10a.

[0030] The gap material 40 only needs to be placed in at least the first region 10g, and may or may not be placed in other positions on the upper surface 10a. For example, in this embodiment, the gap material 40 is placed in the region between the adhesive 50 and the second side surface (second region 10i) and the third region 10h, which will be described later, when viewed in the front-rear direction, but the gap material 40 is not placed on the groove portion 11 side of the adhesive 50. The gap material 40 does not need to be placed in the second region 10i or the third region 10h, and the gap material 40 may be placed on the groove portion 11 side of the adhesive 50. Furthermore, although this embodiment shows a configuration in which the gap material 40 is placed over substantially the entire surface of the first region 10g, it is not limited to this. For example, the gap material 40 may be placed only on the adhesive 50 side of the first region 10g, or the gap material 40 may be placed only on the first side (front surface 10c) side. In Figure 2, only the first region 10g, second region 10i, and third region 10h of the adhesive 50b applied to the region to the right of the groove 11 on the upper surface 10a are shown. The first region 10g, second region 10i, and third region 10h of the adhesive 50a applied to the region to the left are located in mirror-symmetric positions across the groove 11 of the first region 10g, second region 10i, and third region 10h of the adhesive 50b.

[0031] During the manufacturing process of the inductor 100, the adhesive 50, sandwiched between the first core 10 and the second core 20, attempts to spread radially between the first core 10 and the second core 20. The adhesive 50, which attempts to spread in the direction of extension of the conductor 30, is blocked by the gap material 40 placed in the first region 10g. This prevents the adhesive 50 from leaking out to the front or back of the inductor 100, making it difficult for the adhesive 50 to adhere to the outer surface arrangement portion 32 and terminal portion 33 of the conductor 30 located in front of or behind the inductor 100. As a result, good solder wettability is maintained at the outer surface arrangement portion 32 and terminal portion 33, making it easier to form solder fillets when joining to the mounting board by soldering or the like.

[0032] The first core 10 has third and fourth sides (left side 10e and right side 10f in this embodiment) that are positioned in an orthogonal direction (left-right direction) perpendicular to the extending direction (front-back direction) of the groove 11 and face each other. The gap material 40 is further positioned between the adhesive 50 and the third side of the third and fourth sides that is close to the adhesive 50 when viewed in the left-right direction. The third side adjacent to the adhesive 50 is one of a pair of sides of the first core 10 that are arranged in the left-right direction and face each other, and which is located at a distance of less than half the left-right length of the upper surface 10a of the first core 10 with respect to the adhesive 50. In this embodiment, the third side is the side located on the widthwise outer side opposite to the side with the groove 11 when viewed from the adhesive 50, and the fourth side is the side located beyond the groove 11 when viewed from the adhesive 50. In this embodiment, the third and fourth sides are either the left side 10e or the right side 10f, respectively. For example, for adhesive 50a applied to the area to the left of the groove 11 on the upper surface 10a, the third side is the left side 10e and the fourth side is the right side 10f. For adhesive 50b applied to the area to the right of the groove 11, the third side is the right side 10f and the fourth side is the left side 10e. The gap material 40 is positioned on the upper surface 10a in the region between the adhesive 50 and the third side surface (third region 10h) when viewed in the left-right direction. In this embodiment, the gap material 40 is shown to be positioned over substantially the entire third region 10h, but this is not the only configuration. For example, the gap material 40 may be positioned only on the adhesive 50 side of the third region 10h, or only on the third side surface side.

[0033] The adhesive 50, which spreads to the opposite side of the groove 11 as it is sandwiched between the first core 10 and the second core 20, is blocked by the gap material 40 located in the third region 10h. As a result, the appearance of the inductor 100 can be maintained in good condition without the adhesive 50 leaking out to the left or right of the inductor 100 and deteriorating its appearance.

[0034] In this embodiment, a gap material 40 positioned between the adhesive 50 and the first side surface, and a gap material 40 positioned between the adhesive 50 and the third side surface are formed as a single continuous piece. Here, "forming the gap material 40 as a single unit" means not only that it is formed as a single gap material 40, but also that two gap materials 40 are in contact with each other with an extremely small gap, or no gap at all. In other words, the gap material 40 may be formed as a single component, or it may be divided into two or more components. For example, one L-shaped gap material 40 may be formed that spans the first region 10g and the third region 10h. Alternatively, a gap material 40 placed in the first region 10g (for example, gap material 40g described later) and a gap material 40 placed in the third region (for example, gap material 40h described later) may be in contact with each other to form an overall L-shape.

[0035] By making the gap between the gap material 40 located in the first region 10g and the gap material 40 located in the third region 10h as small as possible or even nonexistent, it is possible to prevent the adhesive 50 from leaking out to the outer surface of the inductor 100 through the gap.

[0036] In this embodiment, the gap material 40 is further positioned between the adhesive 50 and the second side surface, continuously surrounding the adhesive 50 in at least three directions. Here, the three directions are the front-rear direction and the direction opposite to the groove 11 in the adhesive 50. The gap material 40 may also be positioned in the region of the adhesive 50 on the groove 11 side, so that the entire circumference of the adhesive 50 is continuously surrounded by the gap material 40, or the gap material 40 may not be positioned in the region of the adhesive 50 on the groove 11 side. In this embodiment, the gap material 40 is not positioned in at least a portion of the adhesive 50 on the groove 11 side, and the surrounding region 10j, which will be described later, is connected to the groove 11.

[0037] By also placing a gap material 40 in the second region 10i, the adhesive 50 that would otherwise spread toward the second side (back surface 10d) can be blocked by the gap material 40i. This prevents the adhesive 50 from adhering to the conductor 30 positioned along the second side (back surface 10d), and also maintains good wettability of the terminal portion on the second side (back surface 10d). As in this embodiment, by surrounding the adhesive 50 with the gap material 40 on three sides other than the groove 11, the adhesive 50 that would otherwise spread out between the first core 10 and the second core 20 is blocked in three directions by the gap material 40. Furthermore, any adhesive 50 that leaks out from the space surrounded by the gap material 40 spreads towards the groove 11, and a portion of the adhesive 50 flows into the groove 11 or onto the conductor 30. This prevents the adhesive 50 from leaking to the outside of the inductor 100 while also preventing it from overflowing the gap material 40 and leaking out to the outer surface of the inductor 100. In addition, by preventing the adhesive 50 from entering between the gap material 40 and the first core 10 or the second core 20, the gap between the first core 10 and the second core 20 can be controlled to a desired distance regardless of the thickness of the adhesive 50, thereby minimizing the impact on the inductance value. Furthermore, it is preferable that the adhesive 50 spreads in the front-back, left-right, and right directions until its thickness is equal to or less than the thickness of the gap material 40. In other words, it is preferable that the thickness of the adhesive 50 is less than or equal to the thickness of the gap material 40. If, instead of this embodiment, the entire perimeter of the adhesive 50 is surrounded by the gap material 40, it is preferable that the gap material 40 have a shape and dimensions such that the volume of the space surrounded by the gap material 40 is greater than the amount of adhesive 50 applied.

[0038] As shown in Figure 2, in this embodiment, the gap material 40 has a smaller shape and dimensions than the upper surface 10a of the first core 10. That is, there is a gap between the gap material 40 and the first side surface, second side surface, third side surface or groove 11, and there is a distance between them. Because there is a gap between the gap material 40 and the first, second, or third side surface, a space exists between the upper surface 10a of the first core 10 and the lower surface 20b of the second core 20, on the outer side in the front-rear direction of the gap material 40 and on the outer side in the width direction opposite to the groove 11. Suppose the adhesive 50 sandwiched between the first core 10 and the second core 20 unexpectedly seeps into the space between the gap material 40 and the first core 10 or the second core 20 and spreads, leaking a small amount out to the outer side in the front-rear direction of the gap material 40 or on the outer side in the width direction opposite to the groove 11. Even in this case, the adhesive 50 can be contained in the space. This makes it possible to better prevent the adhesive 50 from leaking out in the front-rear and left-right directions of the inductor 100. Furthermore, because there is a gap between the gap material 40 and the groove 11, the joint between the first core 10 and the second core 20 can be confirmed by a front view, as shown in Figure 3. That is, when the inductor 100 is viewed from the front, it can be confirmed that the first core 10 and the second core 20 are joined by the adhesive 50 through the gap between the groove 11 and the gap material 40. As shown in Figure 2, the distance L1 between the gap material 40 and the groove 11 is smaller than the widthwise length of the surrounding region 10j, which will be described later. Furthermore, it is preferable that the distance L1 between the gap material 40 and the groove 11 is shorter than or equal to the distance L2 between the gap material 40 and the first side surface, the distance L3 between the gap material 40 and the second side surface, and the distance L4 between the gap material 40 and the third side surface. In addition, the distance L1 between the gap material 40 and the groove 11 is smaller than the length L5 in the front-rear direction of the gap material 40 that is positioned in front of or behind the adhesive 50 when viewed in the front-rear direction. This makes it possible to suppress leakage of the adhesive 50 to the front or rear of the inductor 100 through the gap between the gap material 40 and the groove 11.

[0039] Furthermore, in this embodiment, a portion of the adhesive 50 is in contact with a portion of the end face of the gap material 40. The end face of the gap material 40 is the surface that connects the surface of the gap material 40 that is in contact with the first core 10 and the surface that is in contact with the second core 20, that is, the side surface of the gap material 40. It is sufficient that at least a portion of the adhesive 50 is in contact with at least a portion of the end face of the gap material 40. In other words, a portion of the adhesive 50 is in contact with a portion of the end face of the gap material 40 that is facing the adhesive 50. Here, "the adhesive 50 contacting the end face of the gap material 40" includes cases where a portion of the adhesive 50 contacts only the end face of the gap material 40, and cases where a portion of the adhesive 50 contacts the end face of the gap material 40 and also contacts the main surface of the gap material 40. In other words, the adhesive 50 may contact the end face of the gap material 40 and also spread between the gap material 40 and the first core 10 or between the gap material 40 and the second core 20.

[0040] When the adhesive 50 comes into contact with the end face of the gap material 40, the gap material 40 can block the adhesive 50 from spreading as it is sandwiched between the first core 10 and the second core 20. Furthermore, when the adhesive 50 comes into contact with the end face of the gap material 40, the space surrounded by the gap material 40 is filled with the adhesive 50, reducing the volume of air contained within that space. As a result, even when the inductor 100 is used in an environment with extreme temperature fluctuations, the repeated stress load on the adhesive 50 due to the expansion and contraction of air within that space can be kept to a minimum. Consequently, deterioration of the inductor 100 due to aging in an environment with extreme temperature fluctuations can be suppressed.

[0041] Furthermore, the adhesive 50 may be present on the conductor 30 or inside the groove 11. The adhesive 50 that is blocked by the gap material 40 will spread to the side where the gap material 40 is not located (the groove 11 side) and spread inside the groove 11 or on the conductor 30. This prevents the adhesive 50 that is blocked by the gap material 40 from leaking out beyond the gap material 40. In addition, the adhesion of the adhesive 50 to the groove 11 and the conductor 30 will fix the groove 11 and the conductor 30 together.

[0042] As shown in Figure 2, the adhesive 50 is applied to the upper surface 10a of the first core 10 on both sides of the groove 11, and a pair of gap materials 40 are positioned on both sides of the groove 11 in an orthogonal direction (left-right direction) perpendicular to the extending direction of the groove 11. Specifically, the gap material 40 is placed in the first region 10g of the adhesive 50 applied to both sides of the groove 11 in the left-right direction, preferably in the third region 10h, and more preferably in the second region 10i. In this embodiment, the gap material 40 is formed and positioned with the same symmetry as the adhesive 50. That is, if the adhesive 50 is positioned on the upper surface 10a of the first core 10 in a mirror-symmetric position with respect to the groove 11 (a line passing through the center in the left-right direction), the gap material 40 is also formed in a mirror-symmetric shape with respect to the groove 11 and positioned in a mirror-symmetric position. Furthermore, if the adhesive 50 is positioned in a point-symmetric position with respect to the center point of the upper surface 10a of the first core, the gap material 40 is formed in a point-symmetric shape with respect to the center point of the upper surface 10a of the first core 10 and positioned in a point-symmetric position. Furthermore, the adhesive 50 and gap material 40 only need to be applied and positioned on both sides of the groove 11 on the upper surface 10a of the first core 10 when the inductor 100 is provided. For example, in the process of manufacturing the inductor 100, the adhesive 50 may be applied to the lower surface of the second core 20 and the gap material 40 may be positioned so that when the first core 10 is assembled, the adhesive 50 is applied and the gap material 40 is positioned on both sides of the groove 11.

[0043] If the first core 10 has multiple grooves 11, it is sufficient that adhesive 50 is applied to both sides (left and right) of at least one of the grooves 11 and that a gap material 40 is placed therein. For example, if two grooves 11 extending in the front-rear direction are provided side-by-side and parallel on the upper surface 10a, and the upper surface 10a is divided into three regions by the grooves 11, it is sufficient that adhesive 50 is applied to any two of the three regions or all of the regions and that a gap material 40 is placed therein. If the first core 10 has multiple grooves 11, it is preferable that adhesive 50 is applied to both sides of all grooves 11 and that a gap material 40 is placed therein. For example, when placing gap material 40 or adhesive 50 in the entire area partitioned by the groove 11, the adhesive 50 may be applied to all three areas separated by the groove 11, as shown in Figure 7(a). The gap material 40 is placed on both sides in the front-to-back direction of the adhesive 50. Furthermore, in the case of adhesive 50 applied to the outside in the left-to-right direction, gap material 40 is also placed in the area opposite to the groove 11. Alternatively, as shown in Figure 7(b), only gap material 40 may be placed in the area of ​​the upper surface 10a sandwiched between the two grooves 11.

[0044] By joining the first core 10 and the second core 20 on both sides of the groove 11 on the upper surface 10a, the joint between the first core 10 and the second core 20 can be made stronger. In addition, by placing the gap material 40 in the first region 10g, second region 10i, or third region 10h of the adhesive 50 applied on both sides of the groove 11, it is possible to prevent the adhesive 50 from leaking out of the inductor 100. Furthermore, by arranging the gap material 40 on both sides of the groove 11 on the upper surface 10a, the gap between the first core 10 and the second core 20 can be maintained at a desired distance across the entire upper surface 10a.

[0045] The first core 10, the second core 20, and the gap material 40 according to this embodiment can also be provided as a core set that does not include the conductor 30 or the adhesive 50. The core set comprises a first core 10, a second core 20, and a gap material 40. As described above, the first core 10 is a magnetic material having grooves 11 on its upper surface 10a, and the second core 20 is a magnetic material used in combination with the first core 10 so as to cover the grooves 11. The gap material 40 (40g, 40h, 40i) is placed on the upper surface 10a of the first core 10. The gap members 40 (40g, 40i) are arranged on the upper surface 10a of the first core 10, on both sides in the extending direction (front-rear direction) of the groove 11. Here, the regions on both sides in the extending direction of the groove 11 refer to both one side (front side) and the other side (rear side) with respect to the center of the length in the front-rear direction on the upper surface 10a. That is, at least one gap member 40g is arranged in front of the center in the front-rear direction on the upper surface 10a, and at least one gap member 40i is arranged behind it. As shown in Figure 2, the gap material 40g and gap material 40i have a width that can cover substantially the entire width from the third side (left side 10e or right side 10f) to the groove 11, but are not limited to this. The gap material 40g and gap material 40i only need to cover a portion of the width from the third side to the groove 11, and may not cover a portion. Preferably, the gap material 40g positioned on the front side and the gap material 40i positioned on the rear side overlap in at least a portion when viewed from either direction in the extending direction of the groove 11. More preferably, the entirety of the gap material 40g positioned on the front side and the entirety of the gap material 40i positioned on the rear side overlap when viewed from either direction in the extending direction of the groove 11. A portion of the area sandwiched between the gap materials 40 positioned on both sides in the front-to-back direction is the area where adhesive 50 is to be applied (adhesive application area 10k). It is desirable that the gap material 40 is fixed to the upper surface 10a of the first core 10. For example, a gap material 40 having an adhesive layer as described above may be used, and the gap material 40 may be attached to the upper surface 10a of the first core 10.

[0046] The core set is used by positioning the conductor 30 so as to fit into the groove 11 of the first core 10, and applying adhesive 50 to the upper surface 10a of the first core 10 or the lower surface 20b of the second core 20 to join the first core 10 and the second core 20. By applying the adhesive 50 to the adhesive application area 10k between the gap material 40g and gap material 40i positioned on both sides in the extending direction of the groove 11, the adhesive 50 that spreads in the front-rear direction while sandwiched between the first core 10 and the second core 20 is blocked by the gap material 40g and gap material 40i. Since leakage of the adhesive 50 to the front and rear of the inductor 100 is prevented, the adhesive 50 is less likely to adhere to the conductor 30 positioned on the front surface 10c and back surface 10d, and the solder wettability of the conductor 30 is maintained well.

[0047] Furthermore, the gap members 40g and 40i, which are positioned on both sides in the front-rear direction, may be connected on the side opposite to the groove 11 in the direction perpendicular to the front-rear direction (left-right direction), so that the gap member 40 surrounds at least three sides of a portion of the upper surface 10a (enclosed region 10j). That is, a gap member 40h may be positioned on the side opposite to the groove 11 between the gap member 40g and the gap member 40i. The enclosed region 10j is the region on the upper surface 10a defined by the gap member 40. Gap material 40g, gap material 40h, and gap material 40i may each be different components, or they may be a single component. The enclosed area 10j only needs to be surrounded by the gap material 40 on at least three sides: both sides in the direction of extension of the groove 11 and the side opposite the groove 11. The side of the groove 11 may or may not be surrounded by the gap material 40.

[0048] The adhesive 50 is applied within the enclosed area 10j. That is, the enclosed area 10j and the area 10k to be coated with adhesive overlap. In this embodiment, substantially the entire area 10k to be coated with adhesive is within the enclosed area 10j, and a portion of the area 10k to be coated with adhesive includes the area outside the groove 11 side of the enclosed area 10j. Alternatively, the entire area 10k to be coated with adhesive may be completely contained within the enclosed area 10j. Furthermore, in this embodiment, the center of the adhesive application area 10k (adhesive application center 10l) is located within the surrounding area 10j. Specifically, the adhesive application center 10l is located in the length center of the surrounding area 10j in the front-to-back direction. Also, the adhesive application center 10l is located on the groove 11 side of the length center of the surrounding area 10j in the left-to-right direction. Specifically, it is located in the middle between the groove 11 and the boundary of the surrounding area 10j on the opposite side of the groove 11. Alternatively, the adhesive application center 10l may be located in the length center of the surrounding area 10j in the left-to-right direction.

[0049] By applying the adhesive 50 to the surrounding area 10j, the adhesive 50, which is sandwiched between the first core 10 and the second core 20 and spreads to the opposite side of the groove 11, is blocked by the gap material 40. This prevents the adhesive 50 from leaking out onto the outer surface of the inductor 100.

[0050] (Inductor manufacturing method) The method for manufacturing the inductor of this embodiment (hereinafter sometimes referred to as "this method") will be described below.

[0051] First, I will explain the outline of this method. The inductor 100 manufactured by this method comprises a first core 10, a second core 20, a conductor 30, a gap material 40, and an adhesive 50, as described above. The first core 10 is a magnetic material having a groove 11 on its upper surface 10a, and the conductor 30 is positioned to fit into the groove 11. The second core 20 is a magnetic material that is combined with the first core 10 so as to cover the groove 11. The gap material 40 is sandwiched between the first core 10 and the second core 20 to separate them. The adhesive 50 joins the first core 10 and the second core 20. This method includes a placement step, a cutting step, a removal step, and a joining step.

[0052] Next, we will explain this method in detail. In the placement process, the insulating material 60 is placed so as to cover the upper surface 10a of the first core 10, as shown in Figure 6. The insulating material 60 is a sheet-like material having insulating properties. The insulating material 60 may be composed of a base layer and an adhesive layer laminated together as described above, for example, a tape in which an adhesive layer is coated on an insulating resin layer such as polyimide is an example. When the insulating material 60 is composed of a base layer and an adhesive layer laminated together, the adhesive layer is positioned to be in contact with the upper surface 10a of the first core 10, and the insulating material 60 and the first core 10 are fixed together. This prevents the insulating material 60 from shifting away from the first core 10 during the cutting process. The insulating material 60 only needs to cover at least a portion of the upper surface 10a of the first core 10. Specifically, the insulating material 60 is positioned to cover at least the area on the upper surface 10a where the adhesive 50 is to be applied and its surroundings. More preferably, it covers the entire area to the left or right of the groove 11 on the upper surface 10a, and even more preferably, it covers the entire upper surface 10a. Preferably, the insulating material 60 has a shape and dimensions that include the upper surface 10a of the first core 10. This allows the gap material 40, which is placed on both sides of the groove 11, to be cut out simultaneously during the cutting process.

[0053] In the cutting process, the regions on both sides of the extension direction of the groove 11 from the insulating material 60 are cut out as gap material 40. Here, the regions on both sides of the extension direction of the groove 11 refer to any region on the front side and any region on the rear side, based on the center of the length in the front-rear direction on the upper surface 10a as described above. The insulating material 60 positioned in the front and rear regions is cut out as gap material 40 (40g, 40i), respectively. Preferably, the gap material 40g cut out from the front region and the gap material 40i cut out from the rear region overlap in at least a portion when viewed from either direction of extension of the groove 11. More preferably, the entire gap material 40g cut out from the front region and the entire gap material 40i cut out from the rear region overlap when viewed from either direction of extension of the groove 11.

[0054] In the cutting process, as shown in Figure 2, the region connecting the regions on both sides of the groove extension direction in the insulating material 60, on the opposite side of the groove 11 in a direction perpendicular to the extension direction of the groove 11, may also be cut out as gap material 40. That is, the gap material 40h may be cut out in a way that connects the front and rear regions of the upper surface 10a in a continuous manner on the opposite side of the groove 11. In this case, the gap material 40 surrounds a portion of the upper surface 10a in at least three directions.

[0055] Areas of the upper surface 10a other than those described above may also be cut out as gap material 40. For example, the area connecting the front and rear areas of the upper surface 10a on the groove 11 side may also be cut out as gap material 40.

[0056] Examples of methods for cutting the insulating material 60 include thermal cutting such as laser cutting and physical cutting with a cutting blade. For example, the periphery of the gap material 40 to be cut from the insulating material 60 (the dashed line in Figure 6) can be irradiated from above with a laser to cut the gap material 40 into the desired shape.

[0057] In the removal process, all parts of the insulating material 60 except for the gap material 40 are removed. As a result of the removal process, only the insulating material 60 cut out as the gap material 40 remains on the upper surface 10a, and the insulating material 60 other than the gap material 40 is removed. In this embodiment, the portion of the insulating material 60 excluding the gap material 40 is continuous. Therefore, the insulating material 60 other than the gap material 40 can be removed from the upper surface 10a all at once. For example, as will be described later, if the upper surface 31a of the conductor 30 and the upper surface 10a of the first core 10 are flush, and the gap material 40 is provided in a hollow rectangular shape around the upper surface 10a of the first core, it is necessary to remove the insulating material 60 on the outside and the insulating material 60 on the inside of the gap material 40 separately. Because the portion of the insulating material 60 excluding the gap material 40 is continuous, that portion can be removed all at once, thereby increasing the efficiency of the removal process.

[0058] Furthermore, during the removal process, the insulating material 60 should be peeled off in one of the directions of extension of the groove portion 11. In this embodiment, the portion of the insulating material 60 excluding the gap material 40 has a protruding portion corresponding to the surrounding region 10j. By peeling off the insulating material 60 in a direction that does not include a component opposite to the protruding direction of the protruding portion, it is possible to prevent the protruding portion from remaining unremoved. In this embodiment, the surrounding area 10j is rectangular. Alternatively, the surrounding area 10j may be shaped to narrow outward in the left-right direction. For example, a semicircle, trapezoid, or triangle can be used. This can better prevent residue from remaining on the protruding portion. It also promotes the flow of excess adhesive 50 into the groove 11.

[0059] The conductor 30 is positioned to fit into the groove 11. The conductor 30 is bent to follow the first core 10 and is mounted on the first core 10. Specifically, the conductor 30 extending from the groove 11 is bent and positioned along the front surface 10c and back surface 10d of the first core 10. Both ends of the conductor 30 are bent to contact the lower surface of the first core 10 and positioned on the terminal arrangement portion 14 of the first core 10. Alternatively, the conductor 30, which has been pre-bent to follow the first core 10, may be temporarily spread outward in the direction of extension of the fitting portion 31 and mounted on the first core 10. The step of fitting the conductor 30 into the groove and positioning it along the first core 10 may be performed after the removal step or before the positioning step.

[0060] In the joining process, adhesive 50 is applied to the position corresponding to the removed portion to join the first core 10 and the second core 20. Specifically, adhesive 50 is applied to the adhesive application area 10k between the gap material 40 cut out on both sides in the extending direction of the groove portion 11. More specifically, an adhesive supply unit that dispenses adhesive 50, such as a nozzle, is placed on the adhesive application center 10l, and the adhesive 50 is dispensed and applied to the upper surface 10a of the first core 10. If the area opposite to the groove 11 that connects the gap material 40 on both sides in the extending direction of the groove 11 is also cut out as gap material 40, adhesive 50 is applied to the area of ​​the upper surface 10a surrounded by the gap material 40. The second core 20 is placed on the first core 10 so as to cover the groove 11, and the first core 10 and the second core 20 are joined together by the adhesive 50 through heating and pressurizing.

[0061] Gap material 40 is cut out on both sides in the front-rear direction on the upper surface 10a of the first core 10, and adhesive 50 is applied between the gap material 40. This prevents the adhesive 50 from spreading between the first core 10 and the second core 20 during the joining process, which is then blocked by the gap material 40. As a result, the gap material 40 is prevented from leaking out to the front and rear of the inductor 100, and the adhesive 50 is prevented from adhering to the terminal portion 33. This prevents deterioration of the solder wettability of the terminal portion 33. Furthermore, by placing the insulating material 60 on the first core 10 and then cutting out the gap material 40, the gap material 40 can be cut to match the shape and position of the groove 11 of the first core 10. This makes it easier to position the area to be cut out as the gap material 40.

[0062] The region opposite to the groove 11, which connects the gap material 40 on both sides in the extending direction of the groove 11, is also cut out as gap material 40, and adhesive 50 is applied to the region surrounded by the gap material 40, thereby preventing the adhesive 50 from leaking out to the surface opposite to the groove 11. As a result, leakage of adhesive 50 to the outer surface of the inductor 100 is more effectively prevented, and the appearance of the inductor 100 is maintained in good condition.

[0063] It should be noted that the present invention is not limited to the embodiments described above, and includes various modifications, improvements, and other forms as long as the objectives of the present invention are achieved.

[0064] In this embodiment, the gap material 40 is arranged on both sides of the groove 11 on the upper surface 10a of the first core 10, that is, on the upper surface 10a excluding the groove 11, but the present invention is not limited thereto. For example, if the upper surface 31a of the conductor 30 and the upper surface 10a of the first core 10 are on the same plane and flush, the gap material 40 may be arranged on the conductor 30. Also, if the upper surface 31a of the conductor 30 is located below the upper surface 10a of the first core 10, the gap material 40 may be arranged on the upper surface 31a of the conductor 30. For example, the gap materials 40 arranged on both sides of the groove 11 may be connected to each other on the conductor 30. Specifically, the gap materials 40 formed in connection with the first region 10g, the second region 10i, and the third region 10h on both sides of the groove 11 may be connected on both sides of the conductor 30 in the direction of extension of the groove 11. That is, the gap materials 40 may be arranged so as to cross the groove 11 on the conductor 30. In this way, the gap materials 40 may be formed in a hollow rectangular shape that spans the groove 11 as a whole.

[0065] Furthermore, the location where the adhesive 50 is applied is not limited to the upper surface 10a of the first core 10. For example, if the upper surface 31a of the conductor 30 and the upper surface 10a of the first core 10 are on the same plane and flush, the adhesive 50 may be applied to the upper surface 31a of the conductor 30. Even if the upper surface 31a of the conductor 30 is located below the upper surface 10a of the first core 10, the adhesive 50 may be applied to the upper surface 31a of the conductor 30. The adhesive 50 may be applied discretely to the respective regions on the upper surface 31a of the first core 10 and the region on the conductor 30 on both sides of the conductor 30 in the left-right direction, or the adhesive may be applied linearly across the conductor 30 in the left-right direction. When the adhesive 50 is applied to the upper surface 10a of the conductor 30, it is preferable that gap material 40 is also provided on both sides of the extension direction of the groove 11 in the adhesive 50 on the upper surface 31a of the conductor 30. Furthermore, if the upper surface 31a of the conductor 30 and the upper surface 10a of the first core 10 are on the same plane and flush, or if the upper surface 31a of the conductor 30 is at approximately the same height as the upper surface 10a of the first core 10, the adhesive 50 may be applied only to the conductor 30 and the gap material 40 may be placed.

[0066] In this embodiment, adhesive 50 is applied to one location in each region on both sides of the groove 11 on the upper surface 10a of the first core 10, but the present invention is not limited thereto. Adhesive 50 may be applied to two or more locations in one region on either side of the groove 11 on the upper surface 10a. In other words, adhesive 50 may be applied to multiple locations in each region on both sides of the groove 11 on the upper surface 10a, and the gap material 40 may be placed there. In that case, it is sufficient that the gap material 40 is placed in the first region 10g of the adhesive 50 applied to at least one location, and it is preferable that the gap material 40 is placed in the first region 10g of all of the adhesive 50. Furthermore, as mentioned above, the first sides of adhesive 50 applied to multiple locations do not necessarily refer to the same side. For example, if adhesive 50 is applied to one location on the front side and one on the rear side, the first side of the adhesive 50 applied to the front side is the front surface 10c, and the first side of the adhesive 50 applied to the rear side is the back surface 10d.

[0067] Furthermore, although this embodiment mainly describes the use of an insulating material 60 consisting of a laminated adhesive layer and a base material layer, the gap material 40 may also be formed from an insulating material 60 that does not have an adhesive layer. In this case, in the cutting process of the manufacturing process of the inductor 100, instead of fixing the gap material 40 to the upper surface 10a of the first core 10 with an adhesive layer, the first core 10 and the insulating material 60 may be fixed to holding jigs (not shown) respectively to prevent displacement between the first core 10 and the insulating material 60. If the first core 10 or the second core 20 and the gap material 40 are not fixed by an adhesive layer, the adhesive 50 can be used to fix the first core 10, the second core 20, and the gap material 40 to each other by contacting the end face of the gap material 40.

[0068] Furthermore, although the conductor 30 is entirely a plate-shaped member in this embodiment, it is not limited to this. For example, the terminal portions 33 at both ends of the conductor 30 may have a planar shape, and the middle of the conductor 30 may be made of wire. Specifically, both ends of the conductor 30 are composed of terminal portions 33 located on the lower surface 20b of the first core 10 and upright portions arranged vertically on the side surface of the inductor 100. The wire is wound around the magnetic legs of the core, etc. Both ends of the wire are wound around a winding terminal electrically connected to the upright portion, and the wire and the terminal portions 33 may be electrically connected.

[0069] The above embodiment encompasses the following technical concepts. (1) An inductor comprising: a first core which is a magnetic material having a groove on its upper surface; a conductor which is fitted into the groove; a second core which is a magnetic material which is combined with the first core so as to cover the groove; a gap material which is disposed between the first core and the second core to separate the first core and the second core; and an adhesive which is applied between the first core and the second core, wherein both ends of the conductor extend from the groove and are arranged along the first and second opposing sides of the first core, respectively, the distance between the first side and the adhesive when viewed in the direction in which the groove extends is equal to or less than the distance between the second side and the adhesive, and the gap material which is disposed between the adhesive and the first side when viewed in the direction in which the groove extends. (2) The inductor according to (1), wherein the first core has third and fourth sides arranged in an orthogonal direction perpendicular to the extending direction and facing each other, and the gap material is further arranged laterally between the adhesive and the third side of the third and fourth sides that is close to the adhesive, when viewed in the orthogonal direction. (3) The inductor according to (2), wherein the gap material disposed between the adhesive and the first side surface and the gap material disposed between the adhesive and the third side surface are formed in a continuous manner. (4) The inductor according to (3), wherein the gap material is further disposed between the adhesive and the second side surface and continuously surrounds the adhesive in at least three directions. (5) The inductor according to any one of (1) to (4), characterized in that a portion of the adhesive is in contact with a portion of the end face of the gap material. (6) The inductor according to any one of (1) to (5), wherein the adhesive is applied to the upper surface of the first core on both sides of the groove, and a pair of gap members are arranged on both sides of the groove in a direction perpendicular to the extending direction of the groove. (7) A core set comprising: a first core which is a magnetic material having grooves on its upper surface; a second core which is a magnetic material used in combination with the first core so as to cover the grooves; and a gap material disposed on the upper surface of the first core, wherein the gap material is disposed on the upper surface on both sides in the direction of extension of the grooves. (8) The core set according to (7), wherein the gap members arranged on both sides in the extending direction are connected on the opposite side of the groove in a direction perpendicular to the extending direction, and the gap members surround at least three sides of a portion of the upper surface. (9) A method for manufacturing an inductor, comprising: a first core having a groove on its upper surface; a conductor fitted into the groove; a second core combined with the first core so as to cover the groove; a gap material sandwiched between the first core and the second core to separate them; and an adhesive for joining the first core and the second core, the method comprising: an arrangement step of arranging an insulating material on the first core so as to cover the upper surface; a cutting step of cutting out the regions of the insulating material on both sides in the direction of extension of the groove as a gap material; a removal step of removing the portion of the insulating material excluding the gap material; and a joining step of applying the adhesive to the position corresponding to the removed portion to join the first core and the second core. (10) In the cutting step, the region of the insulating material opposite to the groove in the direction perpendicular to the extending direction, which connects the regions on both sides, is also cut out as the gap material, the method for manufacturing an inductor according to (9).

Claims

1. A first core is a magnetic material having grooves on its upper surface, A conductor is fitted and positioned in the groove, A second core, which is a magnetic material, is combined with the first core so as to cover the groove portion. A gap material is disposed between the first core and the second core to separate the first core and the second core, The adhesive is applied between the first core and the second core, Both ends of the conductor extend from the groove and are arranged along the first and second opposing sides of the first core, respectively. Viewed in the extending direction of the groove, the distance between the first side surface and the adhesive is equal to or less than the distance between the second side surface and the adhesive. The first core has third and fourth sides that are arranged in an orthogonal direction perpendicular to the extending direction and facing each other, The aforementioned gap material, Viewed in the aforementioned extending direction, between the adhesive and the first side surface, Between the adhesive and the second side surface when viewed in the aforementioned extending direction, When viewed in the orthogonal direction, the adhesive is positioned on the side between the third and fourth sides, the third side that is adjacent to the adhesive, The adhesive is surrounded in a continuous manner in three directions. The gap material is not placed in the region on the groove side of the adhesive. The inductor is characterized in that the surrounding region, which is the region surrounded by the gap material, is connected to the groove.

2. A portion of the aforementioned adhesive, The inductor according to claim 1, characterized in that it is in contact with a part of the end face of the gap material.

3. The adhesive is applied to the upper surface of the first core, on both sides of the groove, The inductor according to claim 1 or 2, wherein the pair of gap members are arranged on both sides of the groove in a direction perpendicular to the extending direction of the groove.

4. A first core is a magnetic material having grooves on its upper surface, A second core is a magnetic material used in combination with the first core so as to cover the groove, The first core has a gap material disposed on the upper surface, The gap material is arranged on the upper surface and on both sides in the direction of extension of the groove, The gap members, arranged on both sides in the extending direction, are connected on the opposite side of the groove in the direction perpendicular to the extending direction, and surround at least three sides of a portion of the upper surface. The gap material is not positioned in the region closer to the groove than the aforementioned partial region. A core set characterized in that the aforementioned portion of the region is connected to the groove portion.

5. A first core having a groove on its upper surface, A conductor is fitted and positioned in the groove, A second core is combined with the first core so as to cover the groove, A gap material is sandwiched between the first core and the second core to separate the first core and the second core, A method for manufacturing an inductor having an adhesive for joining the first core and the second core, A placement step in which an insulating material is placed on the first core so as to cover the upper surface, A cutting process in which regions on both sides of the extending direction of the groove and regions on the opposite side of the groove in the direction perpendicular to the extending direction of the insulating material are cut out as gap material, A removal step in which the portion of the insulating material excluding the gap material is removed, A joining step in which the adhesive is applied to the position corresponding to the removed portion to join the first core and the second core, Includes, The gap material cut out by the cutting process is It surrounds at least three sides of a portion of the upper surface, It is not located in the region closer to the groove than the aforementioned partial region. The aforementioned portion of the region is connected to the groove, A method for manufacturing an inductor, wherein the adhesive is applied to a portion of the area during the joining process.

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