Patent ID: 12260984

DETAILED DESCRIPTION

Various components of a coil component of the present invention do not need to be individually independent existences. For example, a plurality of components may be formed as one member, one component may be formed by a plurality of members, a certain component may be a part of another component, and a part of a certain component and a part of another component may overlap.

Embodiments of the present invention are explained below with reference to the drawings. Note that, in the drawings, corresponding components are denoted by a common sign and redundant explanation is not repeated.

Note that, in the present embodiments, front-rear, left-right, and up-down directions are defined and explained as illustrated. However, this is conveniently defined in order to briefly explain relative relations among components and does not limit directions at the time of manufacturing and at the time of use of a product that implements the present invention. The up-down direction in the present embodiments is a direction orthogonal to the surface of a mounting substrate in the case in which a coil component is placed on the mounting substrate. When the coil component is placed on a horizontal mounting substrate, the up-down direction and the vertical direction coincide. However, when the coil component is placed on an inclined mounting substrate, the up-down direction is a direction inclined with respect to the vertical direction. The front-rear direction and the left-right direction are sometimes referred to as lateral direction. In the present embodiments, the front-rear direction coincides with the axial direction of a coil. The left-right direction is sometimes referred to as width direction of the coil component. The up-down direction is sometimes referred to as the height direction of the coil component or a member in the coil component.

A plane referred to in the present invention means a shape intended to be physically formed into a plane and, naturally, does not need to be a geometrically complete plane.

First Embodiment

(Coil Component)

FIG.1is a perspective view showing an example of a coil component1according to a first embodiment of the present invention.FIG.2is an exploded perspective view of the coil component1.

First, an overview of the coil component1in the present embodiment is explained.

As illustrated inFIG.2, the coil component1in the present embodiment includes a first core10, a base unit30, a terminal unit40, at least one coil50, and a second core20. A housing recess32is formed in the base unit30. In the base unit30, the first core10is housed in the housing recess32. The terminal unit40is provided in the base unit30. The coil50is connected to the terminal unit40. The coil50is spirally disposed around a winding core section12in the first core10and the base unit30. The second core20is disposed above the first core10.

The second core20includes a flat plate section22and legs24. The legs24extend from one end portions in the axial direction of the coil50(core end portions14) of the flat plate section22toward the bottom surface of the housing recess32.

The housing recess32includes a first space34and a second space36. The winding core section12is housed in the first space34. The second space36is a space different from the first space34. The legs24are housed in the second space36.

The base unit30includes leg restricting sections (restricting sections38). The restricting sections38are disposed on the inward side of the legs24in the axial direction.

In the coil component1of the present invention, the second core20disposed above includes the legs24extending downward and the restricting sections of the base unit are disposed on the inward side of the legs24in the axial direction. Accordingly, when the second core20is about to shift in the axial direction with respect to the base unit30or is about to shift to rotate when viewed from above, the restricting sections38restrict the movement of the second core, whereby the shift of the second core is suppressed. Accordingly, it is possible to provide the coil component1in which the second core20disposed above is prevented from being disposed to shift in the axial direction of the coil50with respect to the base unit30or shift to rotate with respect to the base unit30when viewed from above. Note that the second core20shifting in the axial direction of the coil50with respect to the base unit30is sometimes referred to as lateral shift and the second core20shifting to rotate with respect to the base unit30when viewed from above is sometimes referred to as rotational shift.

Subsequently, the coil component1in the present embodiment is explained in detail.

The coil component1is an electronic component including the coil50. The electronic component is a component that can configure a part of an electronic circuit. As the coil component1, a transformer, an antenna, an inductor, or the like is exemplified. The coil component1in the present embodiment is disposed and mounted such that a mounting surface of the terminal unit40explained below is brought into contact with a not-illustrated mounting substrate.

The coil50is a member obtained by a conductive material being spirally disposed. The coil50in the present embodiment is a coil obtained by a coil wire, the cross section of which has a circular shape, being spirally disposed. The coil50may be formed by a coil wire, the cross section of which has a flat shape (a rectangular shape, an elliptical shape, or the like). The coil50is not limited by a manufacturing method and may be a coil in general obtained by a conductive material being spirally formed. In the present embodiment, the coil50is formed by winding the coil wire around the first core10and the base unit30. The coil wire in the coil50may be in press contact with or may be in contact with the upper surface of the first core10or winding core side sections35or a bottom surface section30aof the base unit30. Alternatively, the coil wire may be disposed to bite into the winding core side sections35or the bottom surface section30aof the base unit30. Alternatively, the coil wire may be separated from the upper surface of the first core10or the winding core side sections35or the bottom surface section30aof the base unit30.

Alternative to the present embodiment, the coil50may be formed in advance by spirally disposing the conductive material such that a core portion is hollow. In this case, after the formation of the coil, the first core10and the base unit30may be inserted into a hollow portion of the coil. The inner surface (a peripheral surface of a flat wire) of a winding section53and the first core10or the base unit30may be separated or may be in contact.

The coil component1may include one or a plurality of coils50. In the present embodiment, the coil component1includes two coils50(a first coil51and a second coil52). Both of the axial direction of the first coil51and the axial direction of the second coil52are the front-rear direction. The respective axial directions of the first coil51and the second coil52are disposed in parallel to each other. More specifically, a winding shaft of the first coil51is disposed on the same straight line as a winding shaft of the second coil52.

The coil50includes the winding section53around which the coil wire is wound. The coil50includes drawn-out sections54that are both end portions of the coil wire and parts of the coil wire drawn out from the winding section53. In the coil50in the present embodiment, both the end portions of the coil wire is drawn out. Each of both the end portions is connected to the terminal unit40.

As illustrated inFIG.3, the drawn-out sections54extend toward the terminal unit40(connecting wire sections42). More specifically, as illustrated inFIG.6, the drawn-out sections54are wired along the lower surface of the base unit30and range from the winding section53to the connecting wire sections42. The drawn-out sections54and the connecting wire sections42are electrically connected.

The terminal unit40is an electrode member electrically connected to the coil50. The terminal unit40serves as an input electrode or an output electrode of the coil component1. The terminal unit40is formed of a conductive member such as metal.

As illustrated inFIG.6, two terminal units40are provided in each of two sidewall sections37explained below. The terminal units40include the connecting wire sections42, intermediate sections44, and mounting sections46.

The connecting wire sections42are parts to which the end portions of the drawn-out sections54are connected. The coil component1in the present embodiment is manufactured by the end portions of the drawn-out sections54being bound to the connecting wire sections42and the connecting wire sections42and the end portions of the drawn-out sections54being welded in a manufacturing process. The connecting wire sections42and the drawn-out sections54may be joined by soldering or the like.

The mounting sections46are, in the terminal units40, parts grounded to a substrate (not illustrated) when the coil component1is mounted. Specifically, the mounting sections46include mounting surfaces facing downward. The mounting surfaces and the substrate are come into surface contact. The mounting sections46and the substrate are joined by soldering or the like.

The intermediate sections44are parts disposed between the connecting wire sections42and the mounting sections46. In the present embodiment, the intermediate sections44are embedded in the base unit30. The connecting wire sections42and the mounting sections46are exposed from the base unit30.

The cores (the first core10and the second core20) are members formed by a magnetic material. In the present embodiment, the first core10is a so-called I core and the second core20is a so-called U core. The first core10and the second core20are combined to configure a closed magnetic path. The shapes of the first core10and the second core20are not limited to the shapes described above. For example, the first core10and the second core20may have L shapes and may be combined to form the closed magnetic path. Alternatively, both of the first core10and the second core20may be U cores.

A not-illustrated adhesive may be disposed between the first core10and the second core20. Specifically, an upper surface10aof core end portions14explained below may be bonded to lower surfaces24cof the legs24via the adhesive. A sheet (a spacer sheet of a nonmagnetic body) for forming a gap may be disposed between the first core10and the second core20. Two spacer sheets may be disposed between the core end portion14on the front side and the lower surface24cof the leg24and between a core end portion (the core end portion14) on the rear side and the lower surface24cof the leg24. One spacer sheet may be disposed across both the end portions (the core end portions14and14) in the first core10. That is, one spacer sheet may be disposed on the entire upper surface of the first core10. The spacer sheet may be disposed between the core end portion14on the front side and the leg24and between the core end portion14on the rear side and the leg24.

The first core10is a core disposed below the second core20. In the present embodiment, the first core10is a flat plate extending in the lateral direction. The coil50is wound around the winding core section12corresponding to the center of the first core10in the front-rear direction. Here, the coil50being wound around a predetermined member (the first core10, the base unit30, or the like) means that the coil50is disposed around the predetermined member. Some member may be disposed or may not be disposed between the predetermined member and the coil50. That is, the coil50being wound around the predetermined member includes the coil50being indirectly or directly wound around the predetermined member. In the present embodiment, it can be said that the coil50is indirectly wound around the first core10via the base unit30. Both the end portions of the first core10in the front-rear direction are the core end portions14.

The second core20is a core disposed above the first core10. The second core20may be in contact with the first core10and directly placed on the first core10or may be separated from the upper surface of the first core10and disposed above the first core10. In the present embodiment, the lower surfaces of the legs24of the second core20explained below is in contact with the core end portions14of the first core10and the second core20is directly placed on the first core10.

The second core20includes the flat plate section22and one or a plurality of legs24. Specifically, the second core20includes two legs24adjacent to each of the end portions of the flat plate section22in the front-rear direction. The flat plate section22is a part having a flat plate shape extending in the lateral direction in the second core20. The legs24are parts extending in a direction intersecting a main surface of the flat plate section22in the second core20. The legs24are formed to project downward from the flat plate section22. The legs24may extend in a direction orthogonal to the main surface of the flat plate section22or may extend in an oblique direction.

The base unit30is a member that holds the first core10and the second core20. The base unit30is formed of an insulative material such as resin.

The housing recess32in the base unit30is a space in which the first core10or the second core20are disposed. In the present embodiment, the housing recess32is formed by the base unit30being recessed downward.

The housing recess32houses the first core10. The housing recess32housing the first core10means that at least a part of the first core10is disposed in the housing recess32. In the present embodiment, the entire first core10is disposed in the housing recess32. More specifically, the first core10is disposed to extend across the first space34and the second space36.

The first space34is a space in which the winding core section12of the first core10is housed. Specifically, the first space34is defined by the bottom surface section30aand the winding core side sections35. In the present embodiment, the upper end portion of the first space34is terminated on an imaginary upper surface of the base unit30(an imaginary surface including the upper end portions of the sidewall sections37explained below). A boundary in the front-rear direction of the first space34is explained below.

The winding core side sections35are parts disposed to stand from the bottom surface section30ain the base unit30. In the present embodiment, two winding core side sections35are disposed to be separated in the left-right direction. The winding core section12is disposed between the two winding core side sections35.

The second space36being the space different from the first space34means that the second space36does not overlap the first space34.

The second space36is a space in which at least a part of the leg24of the second core20is disposed. In the present embodiment, the housing recess32includes two second spaces36that house respectively each of a pair of legs24disposed to be separated in the front-rear direction. The two second spaces36are disposed across the first space34in the front-rear direction.

The second space36is defined by the bottom surface section30aand the sidewall section37. The bottom surface section30ais a part including the lower surface of the base unit30. The sidewall section37is a part of a wall formed to stand from the bottom surface section30ain the base unit30and formed in a U shape in plan view to surround the side of the leg24. Specifically, the sidewall section37is disposed on the outward side of the leg24in the front-rear direction and on both the sides of the leg24in the left-right direction. Here, the outward side in the front-rear direction means a side of a peripheral edge of the base unit30in the front-rear direction (a peripheral edge of the base unit30viewed from above). In inward side in the front-rear direction means a side of the center of the base unit30in the front-rear direction (the center of the base unit30viewed from above). The upper end of the second space36in the present embodiment is an imaginary surface including the upper end portion of the sidewall section37(an imaginary surface extending in the lateral direction). In the present embodiment, as illustrated inFIG.5, a part on the upper surface side of the second core20(in particular, the flat plate section22) is disposed above the upper end portion of the sidewall section37. That is, a part on the upper surface side of the flat plate section22is disposed outside an envelope volume of the base unit30. In other words, a part on the lower surface side of the flat plate section22of the second core20is disposed in the housing recess32(in particular, the second space36or the first space34) and a part on the upper surface side of the flat plate section22is disposed on the outside of the housing recess32.

In the second space36in the present embodiment, the core end portion14of the first core10is also disposed in addition to the leg24of the second core20. As in a third embodiment explained below, the core end portion14may not be disposed in the second space36.

Note that, as illustrated inFIG.7A, the housing recess32includes a space between respective second side surfaces38dof a pair of restricting sections38explained below (a space in which boundary portions between the core end portions14and the winding core section12in the first core10are disposed; referred to as boundary space). The boundary space may belong to the first space34or may belong to the second space36.

As illustrated inFIG.7A, the restricting sections38are parts of the base unit30and are parts that can restrict movement of the leg24. Here, the restricting sections38being capable of restricting the movement of the leg24means that the restricting sections38are capable of restricting the leg24from moving with respect to the base unit30in a manufacturing process or a finished product of the coil component1. The restricting sections38being able to restrict the movement of the leg24includes, besides the leg24being restricted from moving in a certain direction with respect to the base unit30in the finished product of the coil component1, the leg24being capable of coming into contact with the restricting sections38and the restricting sections38being able to restrict the leg24from moving in the certain direction with respect to the base unit30in the manufacturing process of the coil component1.

The restricting sections38are disposed adjacent to the leg24to restrict the movement of the leg24. Here, the restricting sections38being adjacent to the leg24means that a separation distance between the restricting sections38and the leg24is a predetermined distance or less. Specifically, the separation distance (a distance D3) between the restricting sections38and the leg24is preferably smaller than a separation distance (a distance D4or a distance D5) between the sidewall section37and the leg24. More specifically, the distance between the restricting sections38and the leg24in the front-rear direction is preferably smaller than the distance (the distance D4) between the sidewall section37and the leg24in the front-rear direction or the distance (the distance D5) between the sidewall section37and the leg24in the left-right direction.

The restricting sections38in the present embodiment are inner wall sections extending in the left-right direction. The inner wall sections are considered to define each of the first space34and the second space36. The inner wall sections are disposed to stand from the bottom surface section30a(seeFIG.2) in the base unit30. The inner wall sections are formed integrally with the sidewall section37.

The shape of the restricting sections38is not limited to the inner wall sections in the present embodiment. For example, the restricting sections38may be column-shaped sections projecting upward from the bottom surface section30a. The column-shaped sections may be formed to be separated from the sidewall section37. Alternatively, the restricting sections38may be projecting sections formed to project to the inner side in the left-right direction from the sidewall section37. The projecting sections may be separated from the bottom surface section30a(seeFIG.2) in the base unit30.

In the present embodiment, the dimension of the base unit30in the front-rear direction is larger than the dimension of the base unit30in the left-right direction. However, the dimension of the base unit30in the left-right direction has a predetermined or larger size with respect to the dimension of the base unit30in the front-rear direction. In other words, concerning a part of the base unit30forming the first space34, the dimension in the left-right direction is larger than the dimension in the front-rear direction. The restricting section38is disposed in a position close to the center of the base unit30in the front-rear direction. More specifically, the distance (a distance D8) in the left-right direction between the center of the base unit30in the left-right direction and the restricting section38(the second side surface38d) is larger than the distance (a distance D9) in the front-rear direction between the center of the base unit30in the front-rear direction and the restricting section38(the center in the front-rear direction of the restricting section38or the main surface on the winding section53side of the restricting section38). A facing interval between the second side surfaces38din the pair of restricting sections38disposed side by side in the left-right direction is larger than the distance in the front-rear direction between a first leg24fand a second leg24g(a facing interval between inner side surfaces24dof the pair of legs24). With a dimension relation explained above, the inner side surfaces24dof the legs24easily come into contact with the restricting sections38(in particular, the second side surfaces38d).

In the present embodiment, the restricting sections38are also winding frame sections that assist in winding the coil50. That is, the restricting sections38are disposed on the outward side of the coil50(the winding section53) in the axial direction. More in detail, the restricting sections38are disposed between the coil (the coil wire in the winding section53) and the legs24in the axial direction.

As illustrated inFIG.7A, the base unit30includes a pair of restricting sections38(a first restricting section38aand a second restricting section38b). The pair of restricting sections38are disposed on both the sides of the first core10in the width direction of the base unit30. Each of the first restricting section38aand the second restricting section38bis adjacent to each of both the end portions of one leg24in the left-right direction. Accordingly, a shift of the leg24is more satisfactorily suppressed.

Note that, in the present embodiment, the second core20includes two legs24. Therefore, in the present embodiment, the restricting sections38are disposed adjacent to both the end portions of each of the legs24. That is, in the present embodiment, the base unit30includes four restricting sections38.

As illustrated inFIG.7B, the leg24includes the inner side surface24dfacing the restricting section38side. An orthogonal direction indicated by an alternate long and short dash line II inFIG.7Bmay be inclined with respect to an axial direction (a direction indicated by an alternate long and short dash line I inFIG.7B). That is, the second core20may be disposed to rotate with respect to the axial direction when viewed from above. The orthogonal direction is a direction orthogonal to the inner side surface. In the present embodiment, it can be also said that the orthogonal direction is a direction in which the pair of legs24and24are disposed side by side.

It is possible to reduce a product error for an angle difference in a linear direction with respect to the axial direction by disposing the second core20to rotate in a predetermined direction. That is, it is possible to reduce a product error of a magnetic characteristic due to a positional shift of the second core20with respect to the first core10.

The inner side surface24dis a flat surface in the present embodiment but may be a slighted curved surface. When the inner side surface24dis the curved surface, a direction orthogonal to a tangential line near the center of the inner side surface24din the left-right direction when viewed from above may be set as the orthogonal direction.

In the present embodiment, the inner side surface24dis opposed to the main surface (a first side surface38cexplained below) of the restricting section38that is the inner wall section. The inner side surface24dand the first side surface38cmay be disposed in parallel. The inner side surface24dmay be disposed in a position intersecting the first side surface38c.

In the present embodiment, the second core20is disposed to rotate counterclockwise with respect to the axial direction. However, the second core20may be disposed to rotate clockwise with respect to the axial direction. An angle (a rotation angle) formed by the orthogonal direction and the axial direction is preferably larger than 0 degrees and smaller than 10 degrees. More preferably, the rotation angle is larger than 0 degrees and smaller than 5 degrees. This makes it possible to reduce occurrence of a shift in the position and the direction in placing the coil component1on the mounting substrate and surface-mounting the coil component1.

In the present embodiment, the dimension (the width dimension) of the leg24in the left-right direction is larger than the dimension (the width dimension) of the core end portion14in the left-right direction. Accordingly, even when the second core20is disposed to rotate with respect to the axial direction, it is possible to prevent an area of a region where the second core20(the lower surfaces24cof the leg24(seeFIG.9B)) and the first core10(the upper surface10aof the core end portion14(seeFIG.9B)) overlap in the up-down direction from greatly decreasing. Accordingly, a large magnetic flux leak is prevented from occurring.

In the present embodiment, the distance between the first restricting section38aof the pair of restricting sections38separated in the left-right direction and the inner side surface24din the front-rear direction is smaller than the distance between the second restricting section38bof the pair of restricting sections38and the inner side surface24din the front-rear direction. The distance between the first restricting section38aand the inner side surface24din the front-rear direction includes a case in which the first restricting section38aand the inner side surface24dare in contact and the distance is zero.

The orthogonal direction and the axial direction may be in parallel as illustrated inFIG.7Ainstead of the orthogonal direction being inclined with respect to the axial direction as illustrated inFIG.7B.

As illustrated inFIG.7B, the leg24is in contact with the first restricting section38aof the pair of restricting sections38. On the other hand, the leg24is separated from the second restricting section38bof the pair of restricting sections38. Specifically, the inner side surface24din the leg24and the first side surface38cin the first restricting section38aare in contact. In a second embodiment explained below, the first side surface38cand the inner side surface24dshown inFIG.10may be in contact or the second side surfaces38dand a side surface (in particular, a surface facing the outward side in the left-right direction) of a step section24eshown inFIG.10may be in contact. By keeping the leg24in contact with the restricting section38, it is possible to more satisfactorily reduce a product error for a positional shift of the second core20with respect to the first core10.

In the present embodiment, the side surface facing the outward side of the leg24in the front-rear direction is in contact with the sidewall section37. Since the leg24is in contact with two parts of the sidewall section37and the restricting section38, the position of the second core20in the base unit30is satisfactorily fixed. In the present embodiment, a form in which each of the pair of legs24is in contact with the two parts of the sidewall section37and the restricting section38is exemplified. However, instead of this, one leg24may be in contact with the sidewall section37and separated from the restricting section38and the other leg24may be in contact with the restricting section38and separated from the sidewall section37.

As illustrated inFIG.8, the first side surface38cis a side surface facing the leg24in the restricting section38. The first side surface38cis also a main surface in the restricting section38that is the inner wall section. In the present embodiment, the first side surface38cis inclined obliquely with respect to a placing direction (the up-down direction). The placing direction is a direction at the time when the second core20is placed on the first core10. In other words, the placing direction is also a direction orthogonal to the upper surface of the first core10or the lower surface of the second core20(the lower surface24cof the leg24).

The distance (a distance D1) between the restricting section38and a lower end portion24ain the leg24is smaller than the distance (a distance D2) between the restricting section38and an upper end portion24bof the leg24.

With the configuration explained above, the second space36is largely opened in an opening section and is narrowed in the vicinity of the bottom surface section30a. As a result, it is possible to dispose the second core20in a desired position on the first core10while keeping easiness of disposing the second core20in the second space36.

Note that, for convenience, the first side surface38cinFIG.8is illustrated as being largely inclined.

The first side surface38cbeing inclined with respect to the up-down direction more specifically means that the first side surface38cis inclined to the outward side in the front-rear direction toward the bottom surface section30aside (downward). Accordingly, the second space36is opened wider upward and is narrower downward. In particular, the dimension of the second space36in the front-rear direction is larger upward and is smaller downward.

In the present embodiment, the first side surface38cis an inclined flat surface but is not limited to this surface. The first side surface38cmay be a curved surface. For example, the first side surface38cmay be a convex surface projecting to the leg side or may be a recessed concave surface.

The distance (the distance D2) between the upper end portion24bof the leg24and the first side surface38cis the distance between the surface at the upper end portion24b(a part on the upper side of the inner side surface24d) and a part (near the upper end) on the upper side of the first side surface38cin the front-rear direction. The distance (the distance D1) between the lower end portion24aof the leg24and the first side surface38cis the distance between the surface at the lower end portion24a(a part on the lower side of the inner side surface24d) and a part (near the lower end) on the lower side of the first side surface38cin the front-rear direction.

As illustrated inFIG.9A, the bottom surface section30aincludes a pair of elevated sections31. As illustrated inFIG.9B, the pair of elevated sections31project upward from a surface (a bottom surface30b) on which the first core10is placed in the bottom surface section30a. The pair of elevated sections31are disposed across the first core10in the width direction of the base unit30. A positional shift of the first core10is satisfactorily suppressed by the pair of elevated sections31.

In the present embodiment, as illustrated inFIG.2, a side surface (a surface facing the inner side in the left-right direction) of the elevated section31continuously ranges to a side surface (a surface facing the inner side in the left-right direction) of the winding core side section35. The side surface of the elevated section31also continuously ranges to the second side surfaces38d(seeFIG.7A) in the restricting section38. That is, the side surface of the elevated section31, the side surface of the winding core side section35, and the second side surface38din the restricting section38are disposed on the same plane (a surface extending in the axial direction). The first core10is positioned in the axial direction by a surface formed by the side surface of the elevated section31, the side surface of the winding core side section35, and the second side surface38din the restricting section38.

As illustrated inFIG.9B, in the present embodiment, the side surfaces of the first core10and the elevated sections31(the side surfaces of the elevated sections31) are separated. That is, gaps are provided between the side surfaces of the first core10and the side surfaces of the elevated sections31. An adhesive or the like may be poured into the gaps. Alternative to the present embodiment, the side surface of the first core10and the side surface of at least one elevated section31may be in contact.

As illustrated inFIG.9B, the lower surface24cof the leg24and the upper surface10aof the core end portion14of the first core10are disposed to be opposed. More specifically, the lower surface24cof the leg24is in surface contact with the upper surface10aof the first core10. Accordingly, compared with when lower surface end portions24hof the leg24of the second core20are not in contact with the upper surface10aof the first core10, a leakage flux between the lower surface end portions24hof the second core20and the upper surface10aof the first core10decreases. In the present embodiment, the leg24is formed wider than the core end portion14. Specifically, both the end portions (the lower surface end portions24h) of the lower surfaces24cof the leg24in the width direction (the left-right direction) of the base unit30are disposed further on the outer side (extend further to the outer side) in the width direction than each of both the end portions (upper surface end portions10a1) of the upper surface10aof the core end portion14in the width direction. In other words, the side surfaces (the side surfaces facing the outer side in the left-right direction) of the leg24are disposed further on the outward side in the left-right direction than the side surfaces (the side surfaces facing the outer side in the left-right direction) of the core end portion14.

Both the end portions (the lower surface end portions24h) of the lower surface24cof the leg24are opposed to and separated from the upper surfaces of the elevated sections31. That is, there are gaps between the lower surface end portions24hand the upper surfaces of the elevated sections31. Since the elevated sections31and the second core20are separated, the first core10and the second core20are more securely in contact. Therefore, a leakage flux between the first core10and the second core20decreases. The elevated sections31made of resin generally have a larger coefficient of thermal expansion than the first core10made of a magnetic material such as ferrite. In contrast, since gaps are provided in the up-down direction between the elevated sections31and the second core20, even when heat is generated at the time of use of the coil component1and the elevated sections31are unexpectedly greatly expanded and deformed upward, the elevated sections31are prevented from coming into contact with the second core20to push up the second core20such that the first core10and the second core20are separated.

Second Embodiment

FIG.10is a cross-sectional view showing an example of the coil component1according to the present embodiment.

First, an overview of the coil component1in the present embodiment is explained.

The coil component1in the present embodiment has the following characteristics like the coil component1in the first embodiment.

The base unit30includes leg restricting sections (the restricting sections38). The restricting sections38are disposed on the inward side of the leg24in the axial direction.

The distance between the restricting sections38and the lower end portion24ain the leg24is smaller than the distance between the restricting sections38and the upper end portion24bof the leg24(seeFIG.8in the first embodiment).

The bottom surface section30aincludes the pair of elevated sections31. The pair of elevated sections31are disposed across the first core10in the width direction of the base unit30(seeFIG.9AandFIG.9Bin the first embodiment).

Both the end portions (the lower surface end portions24h) of the lower surface24care opposed to and separated from the upper surfaces of the elevated sections31(seeFIG.9AandFIG.9Bin the first embodiment).

The leg24in the present embodiment is different from the leg24in the first embodiment in that the leg24in the present embodiment includes a projecting section (the step section24e). The step section24eprojects inward in an orthogonal direction (the front-rear direction inFIG.10) from the inner side surfaces24dof the leg24. The step section24eis disposed between the pair of restricting sections38.

Since the leg24includes the step section24e, it is possible to enlarge a magnetic path cross section by a sectional area of the step section24ewithout increasing the length of a magnetic path formed by the second core20and the first core10. Since the step section24eis disposed between the restricting sections38in the width direction, it is possible to more satisfactorily suppress a lateral shift or a rotational shift of the second core20.

Subsequently, the coil component1in the present embodiment is explained in detail.

The coil component1in the present embodiment is different from the coil component1in the first embodiment in the shape of the leg of the second core.

The step section24ein the present embodiment extends from the upper end to the lower end of the leg24. That is, the step section24eextends in the up-down direction (the paper surface depth direction inFIG.10). Alternative to the present embodiment, the step section24emay be formed in only a part in the up-down direction of the leg24. For example, the step section24emay not be formed near the upper end or near the lower end of the leg24.

The width dimension (the dimension in the left-right direction) of the step section24ein the present embodiment is equivalent to the width dimension of the first core10. For this reason, substantially the entire lower surface of the step section24eis in contact with the upper surface10aof the first core10(seeFIG.9B).

The pair of restricting sections38(the first restricting section38aand the second restricting section38b) disposed to be separated in the left-right direction in the present embodiment as in the first embodiment includes the second side surfaces38dfacing a space between the pair of restricting sections38. The step section24ebeing disposed between the pair of restricting sections38more specifically means that the step section24eis disposed between the respective second side surfaces38dof the pair of restricting sections38.

In the present embodiment, as illustrated inFIG.10, the orthogonal direction of the second core20coincides with the front-rear direction.

Instead of the form illustrated inFIG.10, the orthogonal direction of the second core20may be inclined with respect to the axial direction as illustrated inFIG.7Bin the first embodiment.

In that case, the distance between the second side surface38din one restricting section38(the first restricting section38a) and the step section24eis preferably larger than the distance between the second side surface38din the other restricting section38(the second restricting section38b) and the step section24e. Here, the distance between the second side surface38dof the restricting section38and the step section24eis, for example, the distance in the left-right direction between second side surface38dof the restricting section38and a side surface (a side surface facing the outer side in the left-right direction) of the step section24e.

Preferably, the leg24is in contact with the first restricting section38aof the pair of restricting sections38and the leg24is separated from the second restricting section38bof the pair of restricting sections38.

The second side surface38din the first restricting section38aand the side surface (the side surface facing the outer side in the left-right direction) of the step section24eof the leg24may be in contact. The first side surface38cin the first restricting section38aand the inner side surface24dof the leg24may be in contact.

Third Embodiment

FIG.11AandFIG.11Bare longitudinal sectional views showing an example of the coil component1according to the present embodiment.

First, an overview of the coil component1in the present embodiment is explained.

The coil component1in the present embodiment has the following characteristics like the coil component1in the first embodiment.

The base unit30includes leg restricting sections (the restricting sections38). The restricting sections38are disposed on the inward side of the leg24in the axial direction.

The orthogonal direction of the second core20may be inclined with respect to the axial direction (seeFIG.7Bin the first embodiment).

The leg24is in contact with the first restricting section38aof the pair of restricting sections38and the leg24is separated from the second restricting section38bof the pair of restricting sections38(seeFIG.7Bin the first embodiment).

The distance between the restricting sections38and the lower end portion24ain the leg24is smaller than the distance between the restricting sections38and the upper end portion24bof the leg24(seeFIG.8in the first embodiment).

As illustrate inFIG.11A, the second core20in the present embodiment is common to the second core20in the first embodiment in that the second core20in the present embodiment includes the leg24at each of both the end portions in the axial direction. On the other hand, the first core10in the present embodiment is different from the first core10in the first embodiment in that the first core10is disposed between two legs24in the axial direction.

With the configuration explained above, the end portions of the first core10in the axial direction and the legs24of the second core20can be separated in the axial direction. Accordingly, compared with when the second core20is placed on the core end portions14of the first core10as in the first embodiment and the second embodiment, it is possible to provide a gap between the first core10and the second core20without using a spacer sheet of a nonmagnetic body.

Subsequently, the coil component1in the present embodiment is explained in detail.

The coil component1in the present embodiment is different from the coil component1in the first embodiment and the second embodiment in the shape of a first core and the shape of a second core.

As illustrated inFIG.11A, in the present embodiment, the second core20is placed on the bottom surface section30a. As in the first embodiment, the legs24are disposed in the second space36in the housing recess32.

On the other hand, the first core10in the present embodiment is disposed in only the first space34and is not disposed in the second space36. That is, the first core10is not disposed below the legs24. The entire first core10is the winding core section12. Substantially the entire first core10is disposed on the inner diameter side of the coil50. The first core10is disposed in the front-rear direction between the respective inner side surfaces24dof the pair of legs24disposed to be separated in the front-rear direction.

The distance (a distance D6inFIG.11A) between the first leg24fand the first core10may be larger than the distance (a distance D7inFIG.11A) between the second leg24gand the first core10.

By disposing the first core10to be closer to one leg24of the second core20, it is possible to satisfactorily reduce a product error for the position of the first core10with respect to the position of the second core20. In other words, by disposing the first core10unevenly to the side of one leg24and, in particular, disposing the first core10in contact with one leg24, it is possible to reduce a product error because the first core10can be positioned in the front-rear direction.

Note that a total of the distances (a totaled value of the distance D6and the distance D7) between the first core10and the legs24is constant regardless of whether the first core10is disposed in the center of the pair of legs24and24in the front-rear direction or the first core10is disposed further on the front side or the rear side than the center of the pair of legs24and24in the front-rear direction. That is, by separating the first core10and the second core20(the legs24) in the front-rear direction to form a gap, it is possible to reduce an error of a magnetic characteristic due to the position of the first core10.

Here, the distance between the legs24and the first core10is more specifically the distance in the front-rear direction between the inner side surfaces24dof the legs24and side surfaces facing the outward side in the front-rear direction among the surfaces of the first core10.

The distance D6being larger than the distance D7includes a case in which the distance D7is zero. That is, as illustrated inFIG.11B, the inner side surface24dof the second leg24gand the side surface of the first core10may be in contact.

Note that the present invention is not limited to the embodiments explained above and includes forms such as various modifications and improvements as long as the object of the present invention is achieved.

The embodiments explained above include the following technical ideas.

(1) A coil component comprising:

a first core;a base unit in which a housing recess is formed and the first core is housed in the housing recess;a terminal unit provided in the base unit;at least one coil connected to the terminal unit and spirally disposed around a winding core section in the first core and the base unit; anda second core disposed above the first core, whereinthe second core includes a flat plate section and a leg extending from one end portion in an axial direction of the coil of the flat plate section toward a bottom surface of the housing recess,the housing recess includes a first space in which the winding core section is housed and a second space that is a space different from the first space and in which the leg is housed, andthe base unit includes a leg restricting section disposed on an inward side of the leg in the axial direction.
(2) The coil component of (1), whereinthe leg includes an inner side surface facing the leg restricting section side, andan orthogonal direction, which is a direction orthogonal to the inner side surface, is inclined with respect to the axial direction.
(2-1) The coil component, wherein an angle formed by the orthogonal direction and the axial direction is larger than 0 degrees and smaller than 10 degrees.
(2-2) The coil component, wherein the angle formed by the orthogonal direction and the axial direction is larger than 0 degrees and smaller than 5 degrees.
(2-3) The coil component, wherein a dimension of a lower surface of the leg in a width direction of the coil component is larger than a dimension of an upper surface of a core end portion in the width direction of the coil component.
(3) The coil component of (2), whereinthe base unit includes a pair of the leg restricting sections disposed on both sides of the first core in a width direction of the base unit, andthe leg is in contact with a first leg restricting section of the pair of leg restricting sections and is separated from a second leg restricting section of the pair of leg restricting sections.
(3-1) The coil component, wherein a side surface facing an outward side of the leg in the axial direction is in contact with a sidewall section.
(4) The coil component of (3), whereinthe leg includes a projecting section projecting inward in the orthogonal direction from the inner side surface, andthe projecting section is disposed between the pair of leg restricting sections.
(4-1) The coil component, wherein a distance between a second side surface in one restricting section and a step section is larger than a distance between a second side surface in another restricting section and the step section.
(5) The coil component of (1) to (4), whereina side surface facing the leg in the leg restricting section is inclined obliquely with respect to a placing direction at a time when the second core is placed on the first core, anda distance between the leg restricting section and a lower end portion in the leg is smaller than a distance between the leg restricting section and an upper end portion of the leg.
(5-1) The coil component, wherein a first side surface is inclined to an outward side in a front-rear direction toward a bottom surface section side.
(6) The coil component of (1) to (5), whereina bottom surface section defining the second space in the base unit includes a pair of elevated sections projecting upward from a surface on which the first core is placed in the bottom surface section, the pair of elevated sections being disposed across the first core in a width direction of the base unit.
(7) The coil component of (6), whereina lower surface of the leg and an upper surface of the one end portion are disposed to be opposed,both end portions of the lower surface of the leg in the width direction of the base unit are disposed further on an outer side in the width direction than each of both end portions of the upper surface of the one end portion in the width direction, andboth the end portions on the bottom surface of the second core are opposed to and separated from upper surfaces of the elevated sections.
(8) The coil component of (1) to (7), whereinthe second core includes the leg at each of both end portions in the axial direction, andthe first core is disposed between a pair of the legs in the axial direction.
(9) The coil component of (8), wherein a distance between a first leg of the legs and the first core is larger than a distance between a second leg of the legs and the first core.

REFERENCE SIGNS LIST

1Coil component10First core,10aUpper surface,10alUpper surface end portion,12Winding core section,14Core end portion20Second core,22Flat plate section,24Leg,24aLower end portion,24bUpper end portion,24cLower surface,24dInner side surface,24eStep section,24fFirst leg,24gSecond leg,24hLower surface end portion30Base unit,30aBottom surface section,30bBottom surface,31Elevated section,32Housing recess,34First space,35Winding core side section,36Second space,37Sidewall section,38Restricting section,38aFirst restricting section,38bSecond restricting section,38cFirst side surface,38dSecond side surface40Terminal unit,42Connecting wire section,44Intermediate section,46Mounting section50Coil,51First coil,52Second coil,53Winding section,54Drawn-out section