JP7322920B2 - Coils and coil parts - Google Patents

Description

The present invention relates to coils and coil components.

One of the coils used in electronic components is an alpha winding coil. In this alpha winding coil, a structure is known in which a single winding having a pair of spiral portions facing each other is connected, and the innermost peripheral portions of the pair of spiral portions are connected to each other (for example, see Patent Document 1 ).

JP 2005-057309 A

According to the conventional structure, the number of layers of the spiral portion can be increased by arranging a plurality of pairs of spiral portions facing each other.
However, when increasing the number of layers of a coil, it is necessary to increase the number of coils in units of a pair of spiral parts. is restricted.

SUMMARY OF THE INVENTION An object of the present invention is to provide a coil and a coil component in which the number of layers can be increased on a layer-by-layer basis.

One aspect of the present invention includes a winding portion in which a conductive wire is wound around a winding shaft, and a pair of lead portions drawn out from the winding portion, and the winding portion is attached to the winding shaft. A pair of coil portions adjacent to each other are connected at their inner circumferences, and the inner circumferences of the coil portions other than the pair of coil portions are adjacent to each other. and the lead portions are drawn out from the outer circumferences of the uppermost coil portion and the lowermost coil portion along the winding axis. and

According to the present invention, the number of coil portions can be increased in units of one layer.

It is the perspective view which looked at the coil component which concerns on embodiment of this invention from the upper surface side. It is the perspective view which looked the coil component from the mounting surface side. FIG. 4 is a see-through perspective view showing the internal configuration of the coil component; It is a side view of a coil. FIG. 4 is a perspective view showing a configuration of a connecting portion between an alpha-winding coil portion and an additional coil portion; It is a top view which shows typically the coil seen from the direction of a winding shaft. FIG. 10 is an explanatory diagram of another aspect of the connecting portion; FIG. 10 is an explanatory diagram of a case where the coil has two or more additional coil parts; FIG. 10 is an explanatory diagram of a case where the coil includes additional coil sections both above and below the alpha winding coil section; FIG. 4 is an explanatory diagram of the arrangement of a plurality of connection portions in the winding portion; It is a figure which shows typically the shaping|molding process of a winding part.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view of the coil component 1 according to the present embodiment viewed from the upper surface 12 side, and FIG. 2 is a perspective view of the coil component 1 viewed from the mounting surface 10 side.
A coil component 1 of the present embodiment is configured as a surface-mounted electronic component, and includes a substantially rectangular parallelepiped element body 2 that is an aspect of a substantially hexahedral shape, and a pair of and an external electrode 4 .

Hereinafter, in the element body 2 , the first principal surface facing the mounting substrate (not shown) during mounting is defined as the mounting surface 10 , the second principal surface facing the mounting surface 10 is called the top surface 12 , and the mounting surface 10 A pair of third main surfaces orthogonal to each other is called end surfaces 14 , and a pair of fourth main surfaces orthogonal to the mounting surface 10 and the pair of end surfaces 14 are called side surfaces 16 .
Further, as shown in FIG. 1, the distance from the mounting surface 10 to the upper surface 12 is defined as the thickness of the element body 2, the distance between the pair of side surfaces 16 is defined as the width of the element body 2, and the pair of end surfaces 14 is defined as the width of the element body 2. is defined as the length of the prime field 2.

FIG. 3 is a see-through perspective view showing the internal configuration of the coil component 1. As shown in FIG.
The element body 2 includes a coil 20 and a substantially hexahedral core 30 in which the coil 20 is embedded.

The core 30 is a molded body obtained by compression-molding a mixed powder of magnetic powder and resin into a substantially hexahedral shape by applying pressure and heat while enclosing the coil 20 .

In addition, the magnetic powder of the present embodiment contains particles of two types of particle sizes: large first magnetic particles with a relatively large average particle size and second small magnetic particles with a relatively small average particle size. At the time of compression molding, the second magnetic particles, which are small particles, enter between the first magnetic particles, which are large particles, along with the resin.
The magnetic powder may contain particles having an average particle size between the first magnetic particles and the second magnetic particles, thereby including particles having three or more particle sizes.

In the present embodiment, both the first magnetic particles and the second magnetic particles are particles having a metal particle and an insulating film covering the surface thereof with a thickness of several nanometers to several tens of nanometers. Fe—Si system amorphous alloy powder is used, and zinc phosphate glass is used for the insulating film. By covering the metal particles with the insulating film, the insulation resistance and the withstand voltage are increased.

In the first magnetic particles, the metal particles include Cr-less Fe--C--Si alloy powder, Fe--Ni--Al alloy powder, Fe--Cr--Al alloy powder, Fe--Si--Al alloy powder, Fe-- Ni alloy powder and Fe--Ni--Mo alloy powder may be used.

In addition, in the first magnetic particles and the second magnetic particles, the insulating film may contain other phosphates (magnesium phosphate, calcium phosphate, manganese phosphate, cadmium phosphate, etc.) or resin materials (silicone-based resin, epoxy resin, etc.). resin, phenolic resin, polyamide-based resin, polyimide-based resin, polyphenylene sulfide-based resin, etc.) may be used.

In the mixed powder of the present embodiment, an epoxy resin containing a bisphenol A type epoxy resin as a main component is used as the resin material.
The epoxy resin may be a phenol novolac type epoxy resin.
Also, the resin material may be other than the epoxy resin, and may be two or more types instead of one type. For example, thermosetting resins such as phenol resins, polyester resins, polyimide resins, and polyolefin resins can be used as the resin material in addition to epoxy resins.

As shown in FIG. 3, the coil 20 includes a winding portion 22 in which a conductor wire 50 is wound around a winding axis K, and a pair of lead portions 24 drawn out from the winding portion 22. will be described in detail later. Inside the base body 2 , the coil 20 is embedded in the core 30 with the central axis of the winding part 22 along the direction of the thickness T of the base body 2 . It is pulled out to each of the pair of end surfaces 14 and electrically connected to the external electrode 4 .

Conductive wire 50 used to form coil 20 is covered with an insulating covering material. The insulating coating material includes an insulating coating layer having electrical insulation and a fusion coating layer formed on the insulating coating layer. When the coil 20 is formed, the conductive wire 50 is heated and wound so that the fusion coating layer is melted and the conductive wires 50 are fixed to each other. Also, the coil 20 and the core 30 are reliably insulated by the insulating coating layer.

Each of the pair of external electrodes 4 is an L-shaped member that extends from the end surface 14 of the core 30 over the mounting surface 10, is electrically connected to the lead-out portion 24 of the coil 20 at the end surface 14 of the core 30, and is connected to the mounting surface. At 10, it is electrically connected to the wiring of the mounting substrate by suitable mounting means such as solder.
The shape of the external electrode 4 is not limited to the L-shaped electrode shown in the figure. The external electrode 4 may be, for example, a five-sided electrode extending from the entire surface of the end surface 14 over a portion of each of the mounting surface 10 adjacent to the end surface 14 , the upper surface 12 , and the pair of side surfaces 16 . The bottom electrode may be formed only on the .

The coil component 1 having such a configuration can improve DC superimposition characteristics by using metal magnetic particles for the magnetic powder, so it can be used as a component of an electric circuit in which a large current flows, a choke coil of a DC-DC converter circuit or a power supply circuit. Also, it is used for parts of electronic equipment such as personal computers, DVD players, digital cameras, TVs, mobile phones, smart phones, car electronics, medical and industrial machines. However, the application of the coil component 1 is not limited to this, and it can also be used for, for example, a tuning circuit, a filter circuit, a rectifying/smoothing circuit, and the like.

In the coil component 1 , an element protection layer may be formed over the entire surface of the element 2 excluding the range of the external electrodes 4 . Thermosetting resins such as epoxy resins, polyimide resins and phenol resins, or thermoplastic resins such as polyethylene resins and polyamide resins can be used for the material of the body protective layer. These resins may further contain a filler containing silicon oxide, titanium oxide, or the like.

Next, the coil 20 of this embodiment will be described in detail.
Below, the surface of the coil 20 viewed from the direction orthogonal to the winding axis K is defined as a side surface.

4 is a side view of the coil 20. FIG.
The coil 20 is a wound coil formed by winding a conducting wire 50 around a winding axis K. The conducting wire 50 of this embodiment has a pair of wide surfaces 51 facing each other and has a rectangular cross section. It is a so-called flat wire.

As shown in FIG. 3, the winding portion 22 of the coil 20 includes three coil portions 26 formed by spirally winding the conductor 50 around the winding axis K. These coil portions 26 It overlaps in layers along K. Assuming that the direction of the winding axis K is the vertical direction, the lead portions 24 are led out from the outer circumferences of the coil portion 26 of the first layer, which is the uppermost layer, and the coil portion 26 of the third layer, which is the lowermost layer. ing.

In this winding portion 22, the coil portions 26 of the first and second layers are wound by alpha winding to be connected to each other on the inner periphery, and the coils of the second and third layers The portion 26 is connected to the outer circumference of the coil portion 26 of the second layer and the inner circumference of the coil portion 26 of the third layer. The number of turns of the coil portion 26 of each layer is appropriately determined according to the desired inductance value. In this case, the number of turns of the coil portion 26 of each layer may be the same or different. Since the number of turns of the coil portion 26 of each layer is different, the degree of freedom in setting the inductance value is increased.

Hereinafter, a connection mode in which the inner circumferences of two coil portions 26 are connected to each other is referred to as an "inner-inner connection", and a connection mode in which the outer circumference of one coil portion 26 and the inner circumference of the other coil portion 26 are connected. is called the "outer-inner connection".
A pair of coil portions 26 connected by inner-to-inner connection is called an alpha winding coil portion 27, and the coil portion 26 of a layer (third layer in this embodiment) adjacent to the alpha winding coil portion 27 is an additional coil portion. Call it 28.
That is, the winding portion 22 of the present embodiment includes one alpha winding coil portion 27 and one additional coil portion 28, and the alpha winding coil portion 27 and the additional coil portion 28 extend in the direction of the winding axis K. Arranged in layers, the alpha winding coil portion 27 and the additional coil portion 28 are connected by an outer-to-inner connection.

FIG. 5 is a perspective view showing the configuration of a connecting portion 70 between the alpha-winding coil portion 27 and the additional coil portion 28. As shown in FIG. In the figure, most of the winding portion of the additional coil portion 28 in the lowermost layer is omitted in order to facilitate understanding of the configuration of the connecting portion 70.

The connection portion 70 is a portion that connects the alpha-winding coil portion 27 and the additional coil portion 28 with an outside-inside connection, and includes an introduction portion 72, an extension portion 74, and a lead-out portion 76. As shown in FIG.
The introduction part 72 is a part for introducing the conducting wire 50 on the outer circumference of the alpha winding coil part 27 into the interlayer 29A (FIG. 4) between the alpha winding coil part 27 and the additional coil part 28 . The extending portion 74 is a portion where the conductor wire 50 extends through the interlayer 29A from the introducing portion 72 to the leading portion 76 . The lead-out portion 76 is a portion for leading out the conducting wire 50 from the interlayer 29A to the inner circumference of the additional coil portion 28 .

In the extending portion 74, the conductor wire 50 is arranged with the wide surface 51 facing each of the alpha-winding coil portion 27 and the additional coil portion 28, so that the gap δ ( FIG. 4 ) between the layers 29A is 50 , the height of the coil component 1 is reduced and the inductance is increased.
The conducting wire 50 of this embodiment has a width of 0.180 mm, which is the length of the long side of the rectangular cross section, and a thickness of 0.019 mm, which is the length of the short side. The width of the conducting wire 50 is preferably in the range of 0.080 mm to 0.340 mm, and the thickness of the conducting wire 50 is preferably in the range of 0.017 to 0.120 mm. Between the layers 29B of the pair of coil portions 26 of the alpha winding coil portion 27, the size of the gap is about 0 to 0.01 mm.

The lead-in portion 72 is formed by bending the conducting wire 50 by edgewise bending, so that the protrusion amount from the side surface of the alpha-winding coil portion 27 is suppressed. Edgewise bending is a process of bending a flat wire 50 having a rectangular cross section to the short side of the rectangular cross section.
More specifically, as shown in FIG. 5, the lead-in portion 72 includes a first portion 72A, a second portion 72B, and a third portion 72C in which the conductors 50 extend in different directions.

The first portion 72A is a portion where the extending direction of the conductor wire 50 changes from the circumferential direction of the alpha-winding coil portion 27 (the direction substantially perpendicular to the winding axis K) downward (the downward direction of the winding axis K). The second portion 72B is a portion where the extension direction of the conductor wire 50 changes from the outer circumference to the inner circumference of the alpha winding coil portion 27 . The third portion 72</b>C is a portion where the direction of extension of the conductor 50 changes from the second portion 72</b>B toward the lead-out portion 76 on the inner periphery of the additional coil portion 28 .
The first portion 72A and the third portion 72C are subjected to edgewise bending, and the second portion 72B is subjected to an approximately L-shaped (approximately 90 degrees) bending process. The bending angle of the first portion 72A (the angle of change in the extending direction of the conductor 50) is approximately 90 degrees, and the bending angle of the third portion 72C is slightly smaller than 90 degrees. The bending angles of the first portion 72A and the third portion 72C are preferably in the range of 10 degrees to 90 degrees.

6 is a plan view schematically showing the coil 20 viewed from the direction of the winding axis K. FIG.
Here, both the outer shape and the inner shape of the winding portion 22 when viewed from the direction of the winding axis K are a shape (so-called track shape) in which circular arcs are connected to both ends of a rectangle. It includes a linear portion 80 extending linearly in a direction (a direction orthogonal to the winding axis K in plan view of FIG. 6). By providing the introduction portion 72 (first portion 72A) and the lead-out portion 76 within the range of the straight portion 80, the lead-in portion 72 and the lead-out portion 76 are spaced from the peripheral surface of the alpha winding coil portion 27. Moreover, the amount of protrusion of each of the lead-in portion 72 and the lead-out portion 76 in the radial direction of the winding portion 22 can be suppressed.
The outer shape of the winding portion 22 in plan view may be a polygon, a square with rounded corners, a circle, or the like.

The winding portion 22 has a radial length from the inner peripheral surface to the outer peripheral surface (hereinafter referred to as a winding portion width WA) that is wider than the conductor width WB of the conductor wire 50, and extends through the interlayer 29A. The extended portion 74 is accommodated within the range of the winding portion width WA and does not protrude in the radial direction.

Furthermore, in the present embodiment, the extension portion 74 extends between the introduction portion 72 and the extraction portion 76 while being inclined with respect to the direction in which the linear portion 80 extends. The extending portion 74 may extend parallel to the straight portion 80, or may extend substantially perpendicular to the straight portion 80 as shown in embodiment B of FIG. In the aspect A of FIG. 7, the bending angle of the third portion 72C of the introduction portion 72 is approximately 90 degrees, and in the aspect B of FIG. 7, the third portion 72C is omitted from the introduction portion 72.
Moreover, as shown in the aspect C of FIG. 7, the extension part 74 may extend at an angle so as to connect the introduction part 72 and the lead-out part 76 at the shortest distance. According to Aspect C of FIG. 7, the connection portion 70 can be shortened, and the deterioration of the DC resistance value characteristic of the coil 20 can be suppressed.

Further, the winding portion 22 may include one or more additional coil portions 28 in addition to the additional coil portion 28, as shown in the schematic diagram of FIG. The inner circumference of each additional coil section 28 is connected to the outer circumference of the adjacent additional coil section 28 through a connecting section 70 .
Further, the winding section 22 may comprise additional coil sections 28 both above and below the alpha winding coil section 27, as shown in FIG. Also in this case, the inner circumference of each additional coil section 28 is connected to the outer circumference of the adjacent alpha winding coil section 27 through the connection section 70 .

In this way, the coil 20 is configured such that the additional coil portion 28 is connected to the adjacent coil portion 26 (the alpha winding coil portion 27 or the additional coil portion 28) by the outside-inside connection, so that the additional coil portion 28 is formed into one layer. It is possible to increase in units. As a result, the degree of freedom in adjusting the inductance value, DC resistance value, and thickness T of the coil component 1 including the coil 20 is increased.

In addition, when the coil 20 includes two or more additional coil portions 28 and has a four-layer structure or more, that is, when it includes two or more connection portions 70, as shown in the schematic diagram of FIG. , any two of the connection portions 70 are arranged on the straight portions 80 on both sides of the winding shaft K from the top to the bottom (in FIG. 10, side-by-side alternate arrangement). As a result, compared to a configuration in which each connection portion 70 is arranged only on one of the straight portions 80 on both sides of the winding axis K (in FIG. 10, one-side arrangement), the coil 20 can be The inclination of the uppermost and lowermost alpha winding coil portions 27 or the additional coil portion 28 is suppressed, and the distorted side view shape of the coil 20 is suppressed.

Further, as shown in FIG. 10 , the coil 20 includes the connecting portion 70 so that the direction of the central axis CA of at least one or more coil portions 26 is different from the direction of the central axis CA of the other coil portions 26 . As a result, the effect that the height of the coil 20 or the coil component 1 can be reduced can be obtained.

11A and 11B are diagrams schematically showing the forming process of the winding portion 22 of the coil 20. FIG.
A winding device 90 for forming the winding portion 22 includes a winding core 92 and a rotating jig 94 for winding the conductor wire 50 around the winding core 92 .
When forming the wound portion 22, first, the rectangular wire 50 supplied from a feeding machine or the like is set on a rotary jig 94 (first step), and the rotary jig 94 is rotated to rotate the wire. 50 is wound around the winding core 92 by alpha winding (second step). By this second step, an alpha winding coil portion 27 composed of a pair (two layers) of coil portions 26 is formed.

Next, the rotating jig 94 is moved in the major axis direction KA of the winding core 92 so as to be separated from the alpha winding coil portion 27 , and the additional coil portion 28 is positioned between the alpha winding coil portion 27 and the rotating jig 94 . (third step). Then, the conductive wire 50 is mechanically bent from the outer periphery of the alpha-winding coil portion 27 to the winding core 92 side using an appropriate bending jig to form the connection portion 70 (fourth step).
Next, the rotating jig 94 is rotated to wind the conductor wire 50 around the winding core 92, and the additional coil portion 28 is formed by winding the conductor wire 50 from the inner circumference to the outer circumference of the winding core 92, and the conductor wire 50 is cut on the supply side. (Fifth step).

When forming two or more additional coil portions 28, the third step and the fourth step are repeated.
Further, when forming the connection portion 70 in the fourth step, instead of mechanically bending, while the alpha-winding coil portion 27 is being wound, tension is applied to the lead wire 50 toward the winding core 92 side, thereby Conductor 50 may be bent.

According to this embodiment, the following effects are obtained.

The coil 20 of this embodiment includes a winding portion 22 in which a conductive wire 50 is wound around a winding axis K, and a pair of lead portions 24 drawn out from the winding portion 22 . The winding portion 22 includes at least three layers of coil portions 26 along the winding axis K, and a pair of mutually adjacent coil portions 26 (alpha winding coil portions 27) are connected at their inner circumferences. In addition, the inner circumference of each coil portion 26 (additional coil portion 28) other than the pair of coil portions 26 (alpha winding coil portion 27) is 28). The lead portions 24 are led out from the outer peripheries of the uppermost coil portion 26 and the lowermost coil portion 26 along the winding axis K. As shown in FIG.

According to this configuration, the additional coil portion 28 can be added to the alpha-winding coil portion 27 in units of one layer, and the optimum number of layers can be designed according to the desired characteristics.
In addition, in the coil component 1 including the coil 20, the dimensions of the desired inductance value, DC resistance value, and thickness T can be optimally designed without being limited by the number of layers of the coil portion 26. FIG.

In the coil 20 of the present embodiment, each coil portion 26 may have any external shape, but each coil portion 26 (the alpha winding coil portion 27 and the additional coil portion 28) is It is preferable that the outer shape includes a linear portion 80 extending linearly.
As a result, the conductor wire 50 on the outer circumference of the coil portion 26 is bent within the range of the straight portion 80 and extended to the inner circumference side of the adjacent coil portion 26, so that the conductor wire 50 is bent at the bent portion (first portion). 72A) can be brought into close contact with the peripheral surface of the coil portion 26 without leaving a gap, and the amount of protrusion of the winding portion 22 in the radial direction can be suppressed.

In the coil 20 of the present embodiment, the number of layers of the winding portion 22 may be three or more, but the winding portion 22 includes a coil portion 26 having four or more layers, and an additional coil portion other than the alpha winding coil portion 27. As for 28, it is preferable that any two connecting portions 70 are located at positions sandwiching the winding axis K in a side view in a direction perpendicular to the winding axis K. As shown in FIG.
As a result, the inclination of the alpha winding coil portions 27 in the uppermost and lowermost layers of the coil 20 or the additional coil portion 28 is suppressed, and the distorted side view shape of the coil 20 is suppressed.

In the coil 20 of this embodiment, the number of turns of each coil portion 26 of the winding portion 22 is arbitrary, but it is preferable that the number of turns of at least one of the coil portions 26 is different from the number of turns of the other coil portions 26 . As a result, the coil component 1 including the coil 20 can be designed so that the dimensions of the inductance value, DC resistance value, and thickness T are even more optimal.

In the coil 20 of the present embodiment, the conductor wire 50 may have any shape, but is preferably a rectangular wire having a pair of wide surfaces 51 and a rectangular cross section. In the interlayer 29A between the coil portion 26 and the other coil portion 26 adjacent to the coil portion 26, the conducting wire 50 extends with the wide surface 51 facing each coil portion 26. As shown in FIG.
As a result, the gap δ between the layers 29A can be narrowed, and the height of the coil 20 can be reduced and the inductance can be increased.

In the coil 20 of the present embodiment, the direction of the central axis CA of each coil portion 26 of the winding portion 22 is arbitrary, but the direction of the central axis CA of at least one of the coil portions 26 is the same as that of the other coil portions 26. is preferably different from the direction of the central axis CA of .
As a result, the height of the coil 20 or the coil component 1 can be reduced.

The above-described embodiment is an example of one aspect of the present invention, and can be arbitrarily modified and applied without departing from the scope of the present invention.

Unless otherwise specified, the horizontal and vertical directions, various numerical values, shapes, and materials in the above-described embodiments are ranges that exhibit the same effects as those directions, numerical values, shapes, and materials (so-called equal ranges). including.

1 coil component 2 base body (magnetic body)
4 External electrode 20 Coil 22 Winding part 24 Extraction part 26 Coil part 27 Alpha winding coil part 28 Additional coil part 29A Between layers 50 Lead wire 51 Wide surface 70 Connection part 72 Introduction part 72A First part 72B Second part 72C Third part 74 Extension portion 76 Derivation portion 80 Straight portion CA Central axis K Winding shaft

Claims (7)

a winding portion in which a conductive wire is wound around a winding shaft;
and a pair of drawer portions drawn out from the winding portion,
The winding part is
A coil portion having at least three layers along the winding axis,
A pair of the coil portions adjacent to each other are connected at their inner circumferences,
Each inner periphery of the coil portions other than the pair of coil portions is connected to the outer periphery of the other adjacent coil portion,
The drawer section is
pulled out from outer peripheries of the uppermost coil portion and the lowermost coil portion along the winding axis,
A coil characterized by: The coil part is
Including a linear portion extending linearly in the outer shape viewed from the direction of the winding shaft,
2. The coil according to claim 1, characterized in that: The winding part is
a coil portion having four or more layers;
a plurality of connection portions that connect the inner periphery of the coil portion and the outer periphery of the other coil portion adjacent to the coil portion;
Any two of the connecting portions are positioned to sandwich the winding shaft when viewed from a direction orthogonal to the winding shaft,
3. The coil according to claim 1 or 2, characterized in that: The winding part is
The number of turns of at least one of the coil portions is different from the number of turns of the other coil portions,
4. The coil according to any one of claims 1 to 3, characterized in that: The conducting wire
A flat wire having a pair of wide faces and a rectangular cross section,
2. An interlayer between the coil portion and another coil portion adjacent to the coil portion extends with the wide surface facing the coil portion and the other coil portion. 5. The coil according to any one of 4 to 4. The winding part is
The direction of the central axis of at least one of the coil portions is different from the direction of the central axis of the other coil portions,
6. The coil according to any one of claims 1 to 5, characterized in that: a coil according to any one of claims 1 to 6;
a magnetic body in which the coil is embedded;
an external electrode provided on the surface of the magnetic material and electrically connected to the lead portion of the coil;
A coil component comprising:

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