WO2020166404A1

WO2020166404A1 - Inductor and transformer

Info

Publication number: WO2020166404A1
Application number: PCT/JP2020/003872
Authority: WO
Inventors: 隆芳西山; 尚司安永; 肇志治; 宗丈宮下
Original assignee: 株式会社村田製作所
Priority date: 2019-02-14
Filing date: 2020-02-03
Publication date: 2020-08-20

Abstract

This inductor (1) comprises an annular magnetic core (11) having a center hole (11h), and a coil (12). The coil (12) has a flat part (121) and a projecting part (122) projecting from the flat part (121). The magnetic core (11) is disposed on the flat part (121) of the coil (12) so that the projecting part (122) of the coil (12) is positioned in the center hole (11h) of the magnetic core (11). The tip (122a) of the projecting part (122) of the coil (12) projects from the magnetic core (11) when the inductor (1) is viewed from the side from a direction orthogonal to the Z-axis direction.

Description

Inductors and transformers

The present invention relates to an inductor and a transformer.

An insulating radiating plate consisting of a radiating substrate, an insulating resin, and a wiring substrate, a toroidal core made of a magnetic material having a central hole and a flat portion on the lower surface, and a plurality of jumpers made of rectangular wires bent in a U shape. And a wiring pattern formed on a wiring board are proposed (see, for example, Patent Document 1).

JP 2006-278441 A

However, in the case of the coil component described in Patent Document 1, in the manufacturing process, for example, after placing the toroidal core on the insulating heat sink, a plurality of jumpers are mounted on the wiring substrate of the insulating heat sink one by one. We have to go. Therefore, the manufacturing process of the coil component may be complicated, and it may be difficult to efficiently manufacture the coil component.

The present invention has been made in view of the above reasons, and an object thereof is to provide an inductor and a transformer that can be manufactured efficiently.

In order to achieve the above object, an inductor according to an aspect of the present invention is
An annular magnetic core having a central hole,
A coil having a flat portion and a protruding portion protruding from the flat portion,
The magnetic core is disposed on the flat portion such that the protrusion is located in the center hole.

Further, the inductor according to one embodiment of the present invention is
The tip of the projecting portion may project from the magnetic core when the inductor is viewed from the side in a direction orthogonal to the projecting direction of the projecting portion.

Further, the inductor according to one embodiment of the present invention is
The coil further comprises a first wall,
The first wall portion may be configured in an annular shape along the outer circumference of the magnetic core.

Further, the inductor according to one embodiment of the present invention is
The coil may be formed with a first through hole that penetrates the flat portion and the protruding portion in a first direction in which the protruding portion protrudes.

Further, the inductor according to one embodiment of the present invention is
A second through hole may be formed in the coil.

A transformer according to one aspect of the present invention from another point of view is
An annular magnetic core having a central hole,
A first coil having a flat portion and a protruding portion protruding from the flat portion;
A second coil interposed between the first coil and the magnetic core;
Equipped with
The magnetic core is disposed on the flat portion such that the protrusion is located in the central hole.

A transformer according to one aspect of the present invention from another point of view is
An annular magnetic core having a central hole,
A first coil having a flat portion and a protruding portion protruding from the flat portion;
A second coil arranged outside the first coil;
Equipped with
The magnetic core is disposed on the flat portion such that the protrusion is located in the central hole.

Further, the transformer according to one embodiment of the present invention,
The tip of the protrusion may protrude from the magnetic core when the transformer is viewed from the side in a direction orthogonal to the direction in which the protrusion protrudes.

Further, the transformer according to one embodiment of the present invention,
The second coil may include a wire rod that spirally extends along the circumferential direction of the magnetic core.

Further, the transformer according to one embodiment of the present invention,
The second coil has a second wall,
The second wall portion may be configured in an annular shape along the outer circumference of the magnetic core.

Further, the transformer according to one embodiment of the present invention,
The second coil has a second wall,
The second wall portion may be configured in an annular shape along the outer circumference of the first coil.

According to the present invention, the coil or the first coil has the protruding portion protruding from the flat portion, and the magnetic core is arranged on the flat portion such that the protruding portion is located in the center hole thereof. Accordingly, in the manufacture of the inductor or the transformer, it suffices to arrange the projecting portion in the center hole of the magnetic core, so that, for example, as compared with the configuration in which a plurality of jumpers are arranged along the circumferential direction of the magnetic core, The process can be simplified. Therefore, since the manufacturing process can be simplified, the inductor or the transformer can be manufactured efficiently.

FIG. 3 is an exploded perspective view of the inductor according to the first embodiment of the present invention. FIG. 3 is a plan view of the coil according to the first embodiment. FIG. 2B is a sectional view of the inductor according to the first embodiment taken along the line A-A′ in FIG. 2A. FIG. 3 is a plan view showing an example of a board on which the inductor according to the first embodiment is mounted. FIG. 3B is a cross-sectional arrow view corresponding to the line BB′ of FIG. 3A showing an example of a state in which the inductor according to the first embodiment is mounted on the substrate. 5 is a cross-sectional view of another inductor according to the first embodiment. FIG. FIG. 6 is a cross-sectional view showing an example of a state where another inductor according to the first embodiment is mounted on a substrate. FIG. 6 is a diagram showing a state in which a magnetic material is put into a coil in the method for manufacturing the inductor according to the first embodiment. FIG. 6 is a diagram showing a state in which a magnetic material put into a coil is pressed and solidified in the method for manufacturing the inductor according to the first embodiment. It is a top view of the transformer which concerns on Embodiment 2 of this invention. 6B is a cross-sectional view taken along the line C-C′ of FIG. 6A of the transformer according to the second exemplary embodiment. It is a perspective view of the coil which concerns on a modification. 7B is a cross-sectional arrow view of the inductor according to the modified example, taken along line D-D′ of FIG. 7A. FIG. It is a perspective view of the coil which concerns on a modification. FIG. 8B is a cross-sectional arrow view of the inductor according to the modification, corresponding to the line E-E′ in FIG. 8A. It is sectional drawing of the inductor which concerns on a modification. It is a perspective view of the coil which concerns on a modification. It is a perspective view of the coil which concerns on a modification. It is a top view of the coil which concerns on a modification. FIG. 11B is a cross-sectional arrow view of the inductor according to the modification, corresponding to the line F-F′ in FIG. 11A. It is sectional drawing of the inductor which concerns on a modification. It is a top view of the transformer which concerns on a modification. FIG. 13B is a cross-sectional view taken along the line GG′ of FIG. 13A of the transformer according to the modification. It is a perspective view of the 1st coil and the 2nd coil concerning a modification. FIG. 14B is a cross-sectional view of the transformer according to the modification, taken along the line H-H′ in FIG. 14A.

(Embodiment 1)
Hereinafter, an inductor according to an embodiment of the present invention will be described in detail with reference to the drawings. The inductor according to the present embodiment includes a coil and a magnetic core. The magnetic core is an annular magnetic core having a central hole. The coil has a flat portion and a protruding portion protruding from the center of the flat portion. Then, the magnetic core is arranged on the flat portion so that the projecting portion is located in the center hole.

As shown in FIG. 1, the inductor 1 according to the present embodiment includes a coil 12 and an annular magnetic core 11. The coil 12 is one in which the magnetic core 11 is wound for 3/4 turn, and has a disk-shaped flat portion 121, and a columnar protruding portion 122 that protrudes in the +Z direction from the center of the flat portion 121. The wall portion 123 is cylindrical and protrudes in the +Z direction from the peripheral edge of the flat portion 121. The wall portion 123 is a first wall portion formed in an annular shape along the outer circumference of the magnetic core 11. The coil 12 is made of metal such as iron and copper. In addition, the coil 12 is manufactured by using casting or pressing. As shown in FIG. 2A, the diameter D2 of the flat part 121 when the flat part 121 is viewed from the Z-axis direction is 1 to 10 times the diameter D1 of the projection part 122 when the projecting part 122 is viewed from the Z-axis direction. Is set to. When an AC power supply (not shown) is connected between the protrusion 122 and the wall 123, a current flows radially from the protrusion 122 to the wall 123 as shown by an arrow AR1 in FIG. 2A. Therefore, it is possible to reduce the resistance value of the coil 12 while reducing the thickness TH1 of the flat portion 121 and the thickness TH2 of the wall portion 123 shown in FIG. 2B. The outer diameter D1 of the protrusion 122 is appropriately set based on the rated current value required for the coil 12 and the strength required for the coil 12. The length of the wall portion 123 in the protruding direction of the protruding portion 122 (the direction orthogonal to the wide surface of the flat portion 121) is equal to or longer than the length of the magnetic core 11 in the thickness direction.

Returning to FIG. 1, the magnetic core 11 is a toroidal core formed of a magnetic material such as ferrite, that is, an annular magnetic core having a central hole 11h. Further, the magnetic core 11 is a single toroidal core formed of a magnetic material. As shown in FIG. 2B, the magnetic core 11 is arranged on the flat portion 121 so that the protruding portion 122 of the coil 12 is located in the center hole 11h. The tip 122a of the protrusion 122 of the core 12 protrudes from the magnetic core 11 when the inductor 1 is viewed from the side in a direction in which the protrusion 122 of the core 12 protrudes, that is, a direction orthogonal to the +Z direction. .. In other words, the magnetic core 11 is positioned closer to the flat portion 121 side than the tip 122a of the protrusion 122 in the projection area A1 in the first direction in which the protrusion 122 of the flat portion 121 projects, that is, in the +Z direction. ing. Then, with the magnetic core 11 placed on the main surface 121a of the flat portion 121 of the coil 12 on the +Z direction side, the tip 122a of the protrusion 122 is closer to the +Z direction main surface 11a of the magnetic core 11. Also protrudes in the +Z direction by height W1.

As shown in FIG. 3A, for example, the inductor 1 includes a substrate 101 formed of an insulating material such as glass epoxy resin and bakelite, and a conductor pattern 102a formed on one main surface 101a side in the thickness direction of the substrate 101. , 102b, 102e, 102f and

electrodes

102c, 102d are mounted on the circuit board 100. Here, the conductor pattern 102e is electrically connected to the conductor pattern 102a and the electrode 102c, and is embedded in the substrate 101. The conductor pattern 102e and the conductor pattern 102b are separated from each other in the thickness direction of the substrate 101. As shown in FIG. 3B, in the inductor 1, the magnetic core 11 is arranged on a region between the

conductor patterns

102a and 102b on the main surface 101a of the substrate 101, and then the coil 12 and the magnetic core 11 are arranged. It is mounted on the substrate 101 by being fixed to the substrate 101 so as to cover it. Here, the +Z direction side end of the protrusion 122 of the coil 12 is fixed to the conductor pattern 102a via a conductive member such as solder or silver paste. Further, the end portion of the wall portion 123 of the coil 12 on the +Z direction side is also fixed to the conductor pattern 102b via a conductive member such as solder or silver paste.

In the above description, the example in which the magnetic core 11 is located closer to the flat portion 121 side than the tip 122a of the protrusion 122 in the projection area A1 of the flat portion 121 of the coil 12 in the +Z direction has been described. Not limited to this, for example, as in the inductor 30 shown in FIG. 4A, the tip 12122a of the protrusion 12122 of the coil 12012 and the tip 12123a of the wall 12123 are within the projection area A1 of the flat portion 121 in the +Z direction, It may be located closer to the flat portion 121 than the main surface 11a of the magnetic core 11. In FIG. 4A, the same components as those of the inductor 1 are designated by the same reference numerals as those in FIG. 2B. The inductor 30 may be mounted on a circuit board 12100 having

conductor patterns

12102a and 12102b formed so as to project from the main surface 101a of the board 101, as shown in FIG. 4B, for example. In FIG. 4B, the same components as those of the inductor 1 and the circuit board 100 are designated by the same reference numerals as those in FIG. 3B. Even in this case, since the current flowing through the coil 12012 flows toward the +Z direction side of the main surface 11a of the magnetic core 11, the coil 12012 functions as a coil that winds the magnetic core 11 by 3/4 turns.

Next, an example of a method of manufacturing the inductor 1 according to the present embodiment will be described with reference to FIGS. 5A and 5B. First, as shown in FIG. 5A, the coil 12 is held in a posture in which the flat portion 121 is vertically below the projecting portion 122 and the wall portion 123. Next, for example, using the dispenser N1, the powdery or paste magnetic material 1011 is put into the region between the protrusion 122 and the wall 123 of the coil 12. Subsequently, as shown by an arrow AR2 in FIG. 5B, the magnetic material 1011 put into the coil 12 is pressed by the pressing member P1 to press and solidify the magnetic material 1011. After that, the magnetic material 1011 is sintered by heating the coil 12 in which the magnetic material 1011 pressed inside is arranged. As a result, the inductor 1 as shown in FIG. 2B is manufactured. As described above, in the manufacture of the inductor 1, the coil 12 functions as a so-called container of the powdery or pasty magnetic material 1011. Therefore, the number of variations of the magnetic material 1011 that can be used can be increased.

As described above, according to the inductor 1 of the present embodiment, the coil 12 has the protrusion 122 that protrudes from the central portion of the flat portion 121, and the magnetic core 11 surrounds the protrusion 122. It is arranged. Accordingly, in the manufacture of the inductor 1, it is only necessary to dispose the magnetic core 11 around the projecting portion 122 in the flat portion 121, and thus, for example, a plurality of jumpers (not shown) along the circumferential direction of the magnetic core 11. The manufacturing process can be simplified as compared with the configuration in which is arranged. Therefore, since the manufacturing process can be simplified, the inductor 1 can be efficiently manufactured. Further, for example, the heat dissipation of the coil 12 can be improved as compared with the configuration in which a plurality of jumpers (not shown) are arranged along the circumferential direction of the magnetic core 11.

Further, the coil 12 according to the present embodiment includes the wall portion 123 protruding from the peripheral portion of the flat portion 121 in the +Z direction. As a result, the surface area of the coil 12 becomes larger than that in the case where the coil 12 does not include the wall portion 123, for example, and there is an advantage that the heat dissipation of the coil 12 is correspondingly increased. Moreover, since the strength of the coil 12 in the Z-axis direction is increased, the deformation of the coil 12 when an external force is applied to the coil 12 is suppressed.

Further, the wall portion 123 according to the present embodiment has a cylindrical shape and is arranged so as to surround the protruding portion 122. Thereby, when an AC power supply is connected between the protrusion 122 and the wall 123, a current flows along a direction that extends radially from the protrusion 122 to the wall 123. Therefore, it is possible to reduce the resistance value of the coil 12 while reducing the thickness TH1 of the flat portion 121 and the thickness TH2 of the wall portion 123. Further, since the thickness TH2 of the flat portion 121 and the wall portion 123 can be reduced, the internal volume can be increased while maintaining the same outer dimensions of the coil 12. Therefore, the larger the internal volume of the coil 12, the larger the cross-sectional area of the magnetic core 11 arranged inside the coil 12. Further, since the wall portion 123 has a cylindrical shape, the coil 12 can be easily manufactured by, for example, press working.

(Embodiment 2)
The transformer according to the present embodiment has an annular magnetic core having a central hole, a first coil having a flat portion and a protruding portion protruding from the center of the flat portion, and a first coil disposed outside the first coil. 2 coils. The magnetic core is arranged on the flat portion of the first coil such that the protrusion of the first coil is located in the center hole of the magnetic core.

As shown in FIGS. 6A and 6B, the transformer 7 according to the present embodiment includes a coil 12, a coil 7014, and a magnetic core 7011. 6A and 6B, the same components as those in the first embodiment have the same reference numerals as those in FIGS. 1 and 2B. The coil 12 is a first coil that winds the magnetic core 7011 by 3/4 turns, and includes a disk-shaped flat portion 121, a protruding portion 122 protruding from the central portion of the flat portion 121, and a flat portion 121. It has a protruding portion 122 side in the thickness direction of the flat portion 121 from the peripheral portion, that is, a cylindrical wall portion 123 protruding in the +Z direction.

The magnetic core 7011 is an annular toroidal core formed of a magnetic material, that is, an annular magnetic core having a center hole 7011h. As shown in FIG. 6B, the magnetic core 7011 is arranged on the flat portion 121 of the coil 122 so that the protrusion 122 of the coil 12 is located in the center hole 7011h. The tip 122a of the protrusion 122 of the coil 12 protrudes from the magnetic core 7011 when the transformer 7 is viewed from the side in the direction in which the protrusion 122 of the coil 12 protrudes, that is, the direction orthogonal to the +Z direction. .. In other words, the magnetic core 7011 is located closer to the flat portion 121 side than the tip 122a of the protruding portion 122 in the projection area A1 in the first direction in which the protruding portion 122 of the flat portion 121 projects, that is, in the +Z direction. ing.

As shown in FIG. 6A, the coil 7014 is a second coil interposed between the coil 12 and the magnetic core 7011, and the coil 7104 and the coil 12 are electrically insulated. Further, the coil 12 is arranged outside the coil 7014 when viewed from the center hole 7011h. In the coil 7014, a connecting wire 7142 passing through the upper surface of the magnetic core 7011, a jumper wire 7141 passing through the side surface of the magnetic core 7011, and a jumper wire 7141′ passing through the lower surface of the magnetic core 7011 surround the outer circumference of the coil. The plurality of

jumper wires

7141 and 7141 ′ and the connecting wire 7142 provided above are connected to each other, whereby the coil 7014, which is a wire rod spirally extending along the circumferential direction of the magnetic core 7011, is magnetic. The body core 7011 has a plurality of

jumper wires

7141 and 7141 ′ that are spirally extending along the circumferential direction and a plurality of connecting wires 7142. Each of the plurality of

jumper wires

7141 and 7141′ is formed in a U-shape from a linear member in which the surface of a rectangular wire made of metal such as iron or copper is covered with an insulating film, and as shown in FIG. The main core 7011 is arranged so as to face the −Z direction side main surface 7011b, the outer side surface 7011c, and the inner side surface 7011d. The plurality of connecting wires 7142 are linear members covered with an insulating film, and are arranged so as to face the main surface 7011a of the magnetic core 7011 on the +Z direction side. As shown in FIG. 6A, the plurality of connecting wires 7142 are electrically connected to the ends of the

jumper wires

7141 and 7141 ′ having one end, which are located inside the magnetic core 7011, respectively, and the other ends thereof. In the circumferential direction of the magnetic core 7011, one

jumper wire

7141, 7141 ′ is electrically connected to the end of the

other jumper wire

7141, 7141 ′ that is located outside the magnetic core 7011.

As described above, according to the transformer 7 according to the present embodiment, in the state where the coil 7014 spirally extends along the circumferential direction of the magnetic core 7011, the magnetic core 7011 and the coil 7014 are It has a structure arranged inside the coil 12. Accordingly, in the manufacturing of the transformer 7, it is sufficient to dispose the magnetic core 7011 and the coil 7014 inside the coil 12 in a state where the coil 7014 is arranged around the magnetic core 7011. The manufacturing process can be simplified as compared with a configuration in which two types of coils are spirally wound along the circumferential direction of 7011. Therefore, since the manufacturing process can be simplified, the transformer 7 can be efficiently manufactured.

Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations of the above-described embodiments. For example, as shown in FIGS. 7A and 7B, a coil 2012 is one in which the magnetic core 11 is wound by ½ turn, and has a disk-shaped flat portion 121 and a columnar protruding portion 122. It may be one. Here, the outer shape of the flat portion 121 and the outer shape of the magnetic core 11 when viewed in plan are substantially the same. Then, the protruding portion 122 extends in a direction orthogonal to the wide surface of the flat portion 121. 7A and 7B, the same components as those in the first embodiment are designated by the same reference numerals as those in FIGS. 1 and 2B. As shown in FIG. 7B, in the inductor 2 according to the present modification, the magnetic core 11 has the tip 122a of the protrusion 122 in the projection area A2 of the flat portion 121 in the +Z direction, as in the first embodiment. It is located closer to the flat portion 121 than the flat portion 121. Further, the length of the protruding portion 122 in the protruding direction is longer than the length of the magnetic core 11 in the thickness direction. According to this configuration, the structure is simplified as compared with the inductor 1 according to the first embodiment, and accordingly, the manufacturing process can be simplified.

In the first embodiment, the example in which the protruding portion 122 has a cylindrical shape has been described, but the shape of the protruding portion 122 is not limited to the cylindrical shape. For example, as shown in FIGS. 8A and 8B, the coil 3012 may have a cylindrical protrusion 3122. Here, the flat portion 3121 has a disk shape, and a through hole 3121a penetrating in the thickness direction is formed in the central portion. Here, a first through hole that penetrates the flat portion 3121 and the protruding portion 3122 in the Z-axis direction is formed from the inside of the protruding portion 3122 and the through hole 3121a of the flat portion 3121. The protruding portion 3122 is continuous with the outer peripheral portion of the through hole 3121a of the flat portion 3121 at the end portion on the flat portion 3121 side in the cylinder axis direction. Here, the outer peripheral portion of the through hole 3121a is configured to continuously surround the through hole 3121a. As shown in FIG. 8B, in the inductor 3 according to the present modification, the magnetic core 11 has the tip 3122a of the protrusion 3122 in the projection region A3 of the flat portion 3121 in the +Z direction, as in the first embodiment. It is located closer to the flat portion 3121 than the flat portion 3121. The protrusion 3122 according to the present modification is not limited to a cylindrical shape, and may have, for example, a rectangular tube shape or an elliptic or polygonal tube shape in a plan view.

In the coil 3012 shown in FIGS. 8A and 8B, an extending portion (not shown) extending from the tip of the protrusion 3122 on the +Z direction side in a direction parallel to the XY plane and toward the wall 123. May be provided.

By the way, the inductor 3 according to the present modification can be mounted on a circuit board (not shown) such that a heat generating component (not shown) such as a switching element is arranged inside the protrusion 3122, for example. In this case, since the protruding portion 3122 and the flat portion 3121 surrounding the heat generating component function as a heat radiating member, there is an advantage that the temperature rise of the heat generating component can be suppressed. It is also possible to protect the components arranged inside the protrusion 3122. Further, in the inductor 3 according to the present modification, since the coil 3012 can be entirely made of a plate material, there is an advantage that the coil 3012 can be easily manufactured correspondingly.

Further, like the inductor 4 shown in FIG. 9, the coil 4012 includes a bottomed cylindrical protrusion 4122 and a flat portion 4121 which is plate-shaped and has a through hole 4121a penetrating in the thickness direction at the center thereof. , May be included. Here, the end of the protruding portion 4122 on the flat portion 4121 side in the cylinder axis direction is continuous with the outer peripheral portion of the through hole 4121 a of the flat portion 4121. The protruding portion 4122 has a bottomed cylindrical shape, a bottomed rectangular tube shape, or an oval or polygonal bottomed cylindrical shape in a plan view. The protruding portion 4122 of the coil 4012 is formed by pressing a metal mold corresponding to the shape of the inside of the protruding portion 4122 from one surface side in the thickness direction of a plate material punched by punching a plate-shaped base material to form a base material. It is generated by performing a drawing process to deform. According to this configuration, the coil 4012 can be generated only by performing punching and drawing on one plate-shaped substrate, so that the manufacturing process of the coil 4012 can be simplified.

In the inductor 1 according to the first embodiment, at least one of the cutout portion and the second through hole may be formed in the portion of the coil 12 facing the magnetic core 11. For example, as shown in FIG. 10A, the coil 9012 may have a wall portion 9123 having a cutout portion 9123a and a through hole 9123b. In FIG. 10A, the same components as those in the first embodiment are designated by the same reference numerals as those in FIG. The “second through hole” described in the claims includes not only the through hole 9123b but also the cutout portion 9123a. Here, the cutout portion 9123a is formed in a part of the end portion on the +Z direction side of the wall portion 9123. The portion where the through hole 9123b is formed is not limited to the wall portion 9123 as long as it is a portion facing the magnetic core 11, and may be formed in a part of the flat portion 121, for example. Further, the wall portion 9123 according to the present modification is not necessarily limited to the one in which both the cutout portion 9123a and the through hole 9123b are formed, and any one of the cutout portion 9123a and the through hole 9123b is provided. Only one of them may be formed.

Alternatively, in the inductor 3 according to the modified example described with reference to FIGS. 8A and 8B, at least one of the cutout portion and the through hole may be formed in the protruding portion 3122 of the coil 3012. Specifically, as shown in FIG. 10B, the coil 10012 may have a protrusion 10122 that is cylindrical and has a notch 10122a and a through hole 10122b. In FIG. 10B, the same components as those in the modified example described with reference to FIGS. 8A and 8B are designated by the same reference numerals as those in FIGS. 8A and 8B. Here, the cutout portion 10122a is formed in a part of the end portion of the protruding portion 10122 on the +Z direction side. Further, the protrusion 10122 according to the present modification is not necessarily limited to one in which both the cutout portion and the through hole are formed, and only one of the cutout portion 10122a and the through hole 10122b is provided. May be formed. Further, at least one of the cutout portion and the through hole may be provided in a portion of the coil 3012 that does not face the magnetic core 11. Further, the shape of the through hole is not limited to the through hole 10122b shown in FIG. 10B, and the notch portion 10122a may be included.

According to this configuration, generation of eddy currents in the

coils

9012 and 10012 is suppressed, so that power loss due to eddy currents can be reduced. Furthermore, the eddy current can be further reduced by forming a plurality of holes or slits or forming the holes or slits into a shape extending along the Z-axis direction. Further, according to this configuration, for example, when the

coils

9012 and 10012 are mounted on the substrate and then the

coils

9012 and 10012, the magnetic core 11 and the substrate are heated, the gas filled in the

coils

9012 and 10012 is expanded. It is possible to prevent the internal pressure of the

coils

9012 and 10012 from rising. Therefore, there is an advantage that the deformation of the

coils

9012 and 10012 due to the increase of the internal pressure of the

coils

9012 and 10012 can be prevented.

Further, the coil 12 according to the first embodiment may have a radiation fin. Specifically, as shown in FIGS. 11A and 11B, the coil 5012 includes a disk-shaped flat portion 121, a cylindrical protrusion 122, a cylindrical wall 123, and a plurality of heat radiation fins 5124. , May be included. 11A and 11B, the same components as those in the first embodiment are designated by the same reference numerals as those in FIGS. 1 and 2B. Each of the plurality of heat radiation fins 5124 has a long rectangular plate shape, and is continuously and integrally formed with the flat portion 121. Then, as shown in FIG. 11B, in the inductor 5 according to the present modification, the plurality of heat radiation fins 5124 are arranged in one direction orthogonal to the thickness direction of the flat portion 121 on the side opposite to the protruding portion 122 side of the flat portion 121. Are arranged in parallel at equal intervals. The radiating fins 5124 are not limited to those integrally formed with the flat portion 121, and may be fixed to the flat portion 121 by a fixing member such as a screw or a rivet. Alternatively, it may be fixed by an adhesive.

According to this configuration, heat transfer from the coil 5012 to the surrounding air is promoted by the radiation fins 5124, so that the temperature rise of the coil 5012 is suppressed. Further, according to this configuration, since the radiation fins 5124 have a function of reinforcing the flat portion 121, the deformation of the coil 5012 when an external force is applied to the coil 5012 is suppressed.

Also, for example, like the inductor 6 shown in FIG. 12, a cooling component 6013 that is separate from the coil 12 may be fixed to the flat portion 121 of the coil 12. Here, as the cooling component 6013, for example, a block-shaped heat sink, a Peltier element, or the like can be given. The cooling component 6013 may be fixed to the flat portion 121 by a fixing member such as a screw or a rivet, or may be fixed by an adhesive material. According to this configuration, the cooling component 6013 promotes the heat transfer from the coil 12 to the surrounding air, so that the temperature rise of the coil 12 is suppressed.

In the second embodiment, an example in which the coil 7014 is a second coil having a plurality of jumper wires 7141 and a plurality of connecting wires 7142, which are wires that spirally extend along the circumferential direction of the magnetic core 7011, is described. explained. However, the shape of the second coil is not limited to this. For example, like the transformer 8 shown in FIGS. 13A and 13B, the coil 8013, which is the second coil, winds the magnetic core 7011 by 3/4 turns, and includes the tubular portion 8132 and the extending portion 8131. And a wall portion 8133 may be included. The length of the wall portion 8133 in the protruding direction of the protruding portion 122 (the direction orthogonal to the wide surface of the flat portion 121) is equal to or longer than the length in the thickness direction of the magnetic core 7011. 13A and 13B, the same components as those in the second embodiment are designated by the same reference numerals as those in FIGS. 6A and 6B. The cylindrical portion 8132 has a cylindrical shape, and the protruding portion 122 of the coil 12 is arranged inside. The extending portion 8131 has a disk shape and has a through hole 8131a penetrating in the thickness direction in the central portion. The end portion of the tubular portion 8132 on the −Z direction side is continuous with the outer peripheral portion of the through hole 8131a of the extending portion 8131. The extending portion 8131 extends from the end on the flat portion 121 side in the cylinder axis direction of the cylindrical portion 8132, that is, from the end on the −Z direction side to the side of the end, that is, in the direction orthogonal to the Z axis. It extends to a region between the flat portion 121 and the magnetic core 7011 which are located. The wall portion 8133 is a second wall portion that is cylindrical and has an inner diameter that is longer than the outer diameter of the tubular portion 8132 and that extends in the +Z direction from the entire peripheral portion of the extension portion 8131. That is, the wall portion 8133 is formed in an annular shape along the outer circumference of the magnetic core 7011.

Alternatively, for example, the

coils

3012 and 11013 as shown in FIG. 14A may be provided. Note that, in FIG. 14A, the same components as those of the coil 3012 according to the modification described above are denoted by the same reference numerals as those in FIGS. 8A and 8B. In this case, like the transformer 20 shown in FIG. 14B, the magnetic core 7011 is arranged inside the coil 3012. In FIG. 14B, the same components as those of the transformer 8 described above are denoted by the same reference numerals as those in FIG. 13B. The coil 3012 is a first coil having a disk-shaped flat portion 3121, a cylindrical protruding portion 3122, and a cylindrical wall portion 123. The coil 11013 is a second coil having a tubular portion 11132, an extending portion 11131, and a wall portion 11133, and the wall portion 11133 is arranged outside the wall portion 123 of the coil 3012. That is, the wall portion 11133 is a second wall portion formed in an annular shape along the outer circumference of the coil 3012.

Further, the transformer 8 is formed of an insulating material and includes an insulating sheet (not shown) interposed between the coil 12 and the coil 8013. It should be noted that the transformer 8 is not limited to one including this insulating sheet, and may have, for example, an insulating coating formed on a region facing the coil 12 on the outer wall of the second coil described above. Alternatively, it may be coated with an insulating paint.

According to this configuration, with the magnetic core 7011 disposed inside the coil 8013, the outer wall of the coil 8013 is covered with an insulating sheet, and then the coil 8013 covered with the insulating sheet is covered with the coil 12 to form the transformer 8. Can be produced. Therefore, the manufacturing process can be simplified as compared with the transformer 7 according to the second embodiment. Further, by providing the coil 12 and the coil 8013, the strength of the transformer 8 can be increased.

In the transformer according to the present modification, for example, after the insulating paint is applied to the outer wall of the coil 8013, the metal coating formed on the surface of the insulating paint by using the vapor deposition method, the sputtering method, or the like may be used as the first coil. Good.

In each of the embodiments, an example in which the flat portion 121 of the coil 12 has a disk shape has been described, but the shape of the flat portion 121 is not limited to this, and may have a rectangular plate shape or a flat surface. It may have a plate shape that is oval, polygonal, or the like as viewed. Further, the flat portion 121 is not limited to the plate-like one, and may be a block-like one.

In each of the embodiments, an example in which the magnetic core 11 has an annular shape has been described. However, the shape of the magnetic core 11 is not limited to an annular shape, and may have, for example, a rectangular shape, a triangular shape, or an oval shape in a plan view. Alternatively, it may have a ring shape such as a polygonal shape.

In each of the embodiments, the diameter D2 of the flat portion 121 when the flat portion 121 is viewed from the Z axis direction is 1 to 10 times the diameter D1 of the projection portion 122 when the flat portion 121 is viewed from the Z axis direction. Although the example of setting is described, the diameter D2 is not limited to this, and may be set to 10 times or more the diameter D2.

In the first embodiment, an example in which an AC power supply is connected between the protrusion 122 and the wall 123 has been described, but the invention is not limited to this, and a DC power supply may be connected, for example.

The embodiments and modifications of the present invention (including those described in the note. The same applies hereinafter) have been described above, but the present invention is not limited to these. The present invention includes a combination of the embodiments and the modifications as appropriate, and a combination of the modifications as appropriate.

This application is based on Japanese Patent Application No. 2019-024331 filed on February 14, 2019. The specification of Japanese Patent Application No. 2019-024331, the scope of claims, and the entire drawing are incorporated herein by reference.

The present invention is suitable as an inductor used for mass-produced circuit boards.

1, 2, 3, 4, 5, 6, 30: inductor, 7, 8, 20: transformer, 11, 7011: magnetic core, 11a, 101a, 121a, 7011a, 7011b: main surface, 11h, 7011h: center Hole, 12, 2012, 3012, 4012, 5012, 7014, 8013, 9012, 11013, 12012: coil, 100, 12100: circuit board, 101: substrate, 102a, 102b, 102e, 102f, 12102a, 12102b: conductor pattern, 102c, 102d: electrode, 121, 3121, 4121: flat part, 122, 3122, 4122, 10122, 12122: protruding part, 122a, 3122a, 12122a, 12123a: tip, 123, 9123, 12123: wall part, 1011: magnetic Body material, 3121a, 4121a, 8131a, 9123b, 10122b: through hole, 5124: heat dissipation fin, 6013: cooling component, 7011c, 7011d: side surface, 7141, 7141': jumper wire, 7142: connecting wire, 8131, 11131: extension Projection part, 8132, 11132: Cylindrical part, 8133, 11133: Wall part, 9123a, 10122a: Notch part, A1, A2, A3: Projection area, N1: Dispenser, P1: Pressing member

Claims

An annular magnetic core having a central hole,
A coil having a flat portion and a protruding portion protruding from the flat portion,
The magnetic core is arranged on the flat portion such that the protrusion is located in the central hole.
Inductor.
The tip of the projecting portion projects from the magnetic core when the inductor is viewed from the side in a direction orthogonal to the projecting direction of the projecting portion.
The inductor according to claim 1.
The coil further includes a first wall portion,
The first wall portion is configured in an annular shape along the outer periphery of the magnetic core,
The inductor according to claim 1 or 2.
A first through hole that penetrates the flat portion and the protrusion in a first direction in which the protrusion protrudes is formed in the coil.
The inductor according to any one of claims 1 to 3.
A second through hole is formed in the coil,
The inductor according to any one of claims 1 to 4.
An annular magnetic core having a central hole,
A first coil having a flat portion and a protruding portion protruding from the flat portion;
A second coil interposed between the first coil and the magnetic core;
Equipped with
The magnetic core is arranged on the flat portion such that the protrusion is located in the central hole.
Trance.
An annular magnetic core having a central hole,
A first coil having a flat portion and a protruding portion protruding from the flat portion;
A second coil arranged outside the first coil;
Equipped with
The magnetic core is arranged on the flat portion such that the protrusion is located in the central hole.
Trance.
The tip of the projecting portion projects from the magnetic core when the transformer is viewed from the side in a direction orthogonal to the projecting direction of the projecting portion.
The transformer according to claim 6 or 7.
The second coil has a wire rod that extends spirally along the circumferential direction of the magnetic core.
The transformer according to any one of claims 6 to 8.
The second coil has a second wall portion,
The second wall portion is formed in an annular shape along the outer circumference of the magnetic core.
The transformer according to claim 6.
The second coil has a second wall portion,
The second wall portion is configured in an annular shape along the outer circumference of the first coil,
The transformer according to claim 7.