WO2017073239A1

WO2017073239A1 - Antenna device and power supply device

Info

Publication number: WO2017073239A1
Application number: PCT/JP2016/079225
Authority: WO
Inventors: 田中　光矢; 佐利山口
Original assignee: 株式会社村田製作所
Priority date: 2015-10-26
Filing date: 2016-10-03
Publication date: 2017-05-04
Also published as: CN208078180U

Abstract

Provided is a smaller antenna device with which erroneous operation is minimized and transfer efficiency is kept from declining. There is provided a coil antenna 3 having a coil conductor 2 wound around a winding axis and layered in the winding axis direction to form a space in the interior, and a circuit substrate 4 positioned inside the space formed by the coil conductor 2. The open surface of the coil antenna 3 is of polygonal shape when the coil antenna 3 is viewed from above in the winding axis direction of the coil conductor 2, and the circuit substrate 4 is positioned to follow along the diagonal lines of the polygon.

Description

ANTENNA DEVICE AND POWER SUPPLY DEVICE

The present invention relates to an antenna device, and more particularly, to an antenna device that is miniaturized and in which malfunctions and a decrease in transmission efficiency are suppressed.

The present invention also relates to a non-contact power transmission apparatus that is miniaturized by using the antenna apparatus of the present invention, and that is prevented from malfunctioning and a decrease in transmission efficiency.

Safe and easy-to-use non-contact power transmission devices are widely used for charging storage batteries such as cordless phones, electric shavers, electric toothbrushes, mobile phones and smartphones.

Patent Document 1 (WO2012-101905) discloses such a non-contact power transmission device.

FIG. 5 shows a non-contact power transmission apparatus (switching power supply apparatus) 300 disclosed in Patent Document 1.

The non-contact power transmission device 300 includes a power transmission side resonance circuit composed of resonance capacitors Cr ₁ and Cr ₂ and a resonance inductor Lr, and a power reception side resonance circuit composed of resonance capacitors Crs ₁ and Crs ₂ and the resonance inductor Lrs. , The power transmission is performed mainly by magnetic field coupling between the power transmission side antenna (power transmission coil) Lp and the power reception side antenna (power reception coil) Ls.

In the non-contact power transmission device, downsizing of the power transmission side antenna and the power reception side antenna is an important issue. For example, cordless phones, electric shavers, electric toothbrushes, mobile phones, smartphones, and other devices that incorporate a power-receiving antenna are an important feature, and the power-receiving antenna is necessarily small. Is required. Similarly, it is desirable that the charger of the above-mentioned device in which the power transmission side antenna is incorporated is also small, and the power transmission side antenna is also required to be small.

As a method for reducing the size of the antenna device, a method is conceivable in which a circuit board on which a peripheral circuit is formed is accommodated in the internal space of a coil antenna in which a coil conductor is spirally wound.

For example, Patent Document 2 (WO2009-145218) discloses an antenna device in which a wireless IC chip is accommodated inside a coil antenna.

FIG. 6 shows an antenna device (component for wireless IC device) 400 disclosed in Patent Document 2.

The antenna device 400 has a wireless IC chip 102 disposed inside a coil antenna (annular electrode) 101 for the purpose of miniaturization. The coil antenna 101 of the antenna device 400 is configured by connecting a linear electrode 104 and a via-hole conductor 105 in a spiral shape inside a laminated body (feeding circuit board) 103 configured by laminating a plurality of resin layers. Coil antenna. Note that the wireless IC chip 102 is wired by connection electrodes 106.

WO2012-101905 WO2009-145218

The above-described conventional antenna device 400 includes the wireless IC chip 102 inside the coil antenna 101, and is miniaturized.

However, in the antenna device 400, no consideration has been given to the arrangement position and the arrangement direction of the wireless IC chip 102.

In the antenna device 400, the wireless IC chip 102, the connection electrode 106, and the like are arranged in close proximity to the linear electrode 104 of the coil antenna 101. In addition, the wireless IC chip 102, the connection electrode 106, and the like are arranged in parallel with the linear electrode 104. In such an arrangement, the wireless IC chip 102, the connection electrode 106, and the like and the linear electrode 104 are likely to be coupled by an electric field, a magnetic field, or an electromagnetic field (an electric field and a magnetic field). There is a possibility that the IC chip 102 malfunctions.

Further, the antenna device 400 is not provided with means for suppressing the influence on the wireless IC chip 102 by the magnetic flux generated by the coil antenna 101. Therefore, the magnetic flux generated by the coil antenna 101 is directly linked to the wireless IC chip 102, and the wireless IC chip 102 may malfunction due to the influence thereof.

The present invention has been made to solve the above-described conventional problems.

As the means, the antenna device according to the present invention (the antenna device described in claim 1) includes a coil conductor wound around a winding axis and laminated in the direction of the winding axis to form a space inside. When the coil antenna is viewed in plan in the direction of the winding axis of the coil conductor, the opening surface of the coil antenna has a polygonal shape. The circuit board is arranged along the diagonal of the polygon.

In this case, the polygon of the opening can be, for example, a rectangle. In this case, since the conductor pattern of the circuit board and the electronic component mounted on the circuit board are arranged away from the coil conductor of the coil antenna and are not easily parallel to each other, the conductor pattern, the electronic part, and the coil conductor Can be prevented from being coupled by an electric field, a magnetic field, or an electromagnetic field. Furthermore, when the rectangular shape of the opening is a square, the opening area becomes large, so that the transmission efficiency of the coil antenna can be increased.

Further, in order to solve the above-described conventional problems, the antenna device of the present invention (the antenna device described in claim 2) is wound around the winding axis and laminated in the winding axis direction so as to be internal. A coil antenna having a coil conductor having a space formed therein, and a circuit board disposed in the space formed by the coil conductor, the circuit board having a main surface and a main surface with respect to a winding axis direction of the coil conductor The normals were tilted together. *

Furthermore, in order to solve the above-described conventional problems, the antenna device of the present invention (the antenna device described in claim 3) is wound around the winding axis and laminated in the winding axis direction so as to be internal. A coil antenna having a coil conductor in which a space is formed, and a circuit board disposed in the space formed by the coil conductor when the coil antenna is viewed in plan in the winding axis direction of the coil conductor. When the coil antenna is viewed in plan in the winding axis direction of the coil conductor, the opening surface of the coil antenna is polygonal, the circuit board is arranged along the diagonal of the polygon, and the circuit board is wound around the winding axis of the coil conductor. The main surface and the normal of the main surface are both inclined with respect to the direction.

In these antenna devices of the present invention (antenna devices described in claims 2 and 3), when an electronic component is mounted on a circuit board and the coil antenna is viewed in plan in the winding axis direction of the coil conductor, The center of gravity of the outer shape of the electronic component is preferably included in the outer edge of the circuit board. In this case, it is possible to suppress the magnetic flux generated by the coil antenna from interlinking with the electronic component or the wiring of the electronic component without reducing the transmission efficiency of the coil antenna.

In addition, when the coil antenna is viewed in plan in the winding axis direction of the coil conductor, it is preferable that the entire outer shape of the electronic component is included in the outer edge of the circuit board. In this case, it is possible to suppress the magnetic flux generated by the coil antenna from interlinking with the electronic component or the wiring of the electronic component without further reducing the transmission efficiency of the coil antenna.

The circuit board preferably has a conductor pattern on at least one of the inside and the surface. In this case, the conductor pattern can suppress the magnetic flux generated by the coil antenna from interlinking with the electronic component or the wiring of the electronic component. When the circuit board has a conductor pattern on the surface, the conductor pattern can be used as a land electrode for connecting the electronic component and the circuit board with solder or the like.

Furthermore, a power supply device can be produced by using the antenna device of the present invention for at least one of a power transmission side antenna and a power reception side antenna in a non-contact power transmission system. In this case, it is possible to manufacture a power supply device that is miniaturized and in which malfunction and reduction in transmission efficiency are suppressed.

The antenna device of the present invention (the antenna device described in claim 1) is miniaturized because the circuit board is disposed in the opening surface of the coil antenna. In addition, since the opening surface of the coil antenna is polygonal and the circuit board is arranged along the diagonal line of the polygon, the conductor pattern of the circuit board and the electronic component are arranged away from the coil conductor of the coil antenna. And it becomes difficult to become parallel to the coil conductor of the coil antenna. As a result, the antenna device of the present invention (the antenna device described in claim 1) is less likely to cause unnecessary coupling between the conductor pattern of the circuit board and the electronic component and the coil conductor of the coil antenna, and malfunction is suppressed. Yes.

Also, the antenna device of the present invention (the antenna device described in claim 2) is miniaturized because the circuit board is disposed in the opening surface of the coil antenna. Also, since the main surface of the circuit board and the normal of the main surface are inclined with respect to the winding axis direction of the coil conductor, the magnetic flux generated by the coil antenna is blocked by the circuit board so that the magnetic flux generated by the coil antenna Linkage to component wiring is suppressed, and a reduction in transmission efficiency of the coil antenna due to the circuit board blocking the magnetic flux of the coil antenna is kept small. Therefore, in the antenna device of the present invention (the antenna device described in claim 2), malfunctions and a decrease in transmission efficiency are suppressed. *

Further, the antenna device of the present invention (the antenna device described in claim 3) having the characteristics of both of the two antenna devices described above has the effects of both antenna devices.

1 is a perspective view showing an antenna device 100 according to a first embodiment. 1 is an exploded perspective view showing an antenna device 100. FIG. 1 is a plan view showing an antenna device 100. FIG. FIG. 4A is a front view showing the coil antenna 3 of the antenna device 100. FIG. 4B is a cross-sectional view of the antenna device 100 and shows a ZZ portion of FIG. It is an equivalent circuit schematic of the non-contact electric power transmission apparatus 200 concerning 2nd Embodiment. FIG. 5 is also an equivalent circuit diagram of the non-contact power transmission apparatus 300 disclosed in Patent Document 1. 6 is an internal perspective view of an antenna device (component for wireless IC device) 400 disclosed in Patent Document 2. FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

Each embodiment shows an embodiment of the present invention by way of example, and the present invention is not limited to the content of the embodiment. Further, the drawings are for helping understanding of the embodiment, and may not be drawn strictly. For example, a drawn component or a dimensional ratio between the components may not match the dimensional ratio described in the specification. In addition, the constituent elements described in the specification may be omitted in the drawings or may be drawn with the number omitted.

[First Embodiment: Antenna Device]
1, 2, 3, 4 (A), and (B) show an antenna device 100 according to the first embodiment. However. FIG. 1 is a perspective view of the antenna device 100. FIG. 2 is an exploded perspective view of the antenna device 100. FIG. 3 is a plan view of the antenna device 100. FIG. 4A is a front view of the coil antenna with the case removed from the antenna device 100. FIG. 4B is a cross-sectional view of the antenna device 100 and shows a ZZ portion of FIG.

The antenna device 100 includes a case (housing) 1. The case 1 is made of, for example, resin, has a bottom, and has an open top in a square shape. Note that either the upper or lower side of the case 1 may be open or bottomed, or both may be open or bottomed.

The antenna device 100 includes a coil antenna 3 in which a coil conductor 2 is spirally wound around a winding axis. The coil antenna 3 has a space inside, and is opened in a substantially rectangular shape, specifically, a square shape when viewed in plan in the winding axis direction of the coil conductor 2. The coil antenna 3 is accommodated in the case 1 in close contact with the inner wall of the case 1. In the present embodiment, the coil conductor 2 is made of an insulating coated nichrome wire. The coil antenna 3 may be coated with resin in order to maintain the shape. The shape of the opening of the coil antenna is not limited to a rectangle and a square, and may be any other polygon such as a pentagon and a hexagon and a regular polygon.

The antenna device 100 includes a circuit board 4. The circuit board 4 is made of, for example, resin or ceramic. The circuit board 4 has a substantially rectangular main surface having a long side and a short side, and includes a conductor 5 formed inside and on the surface in parallel with the main surface. The conductor 5 is, for example, a conductor pattern such as a wiring electrode, a land electrode, or a ground electrode extending in a planar shape.

The

electronic components

6 and 7 are mounted on the circuit board 4. In the present embodiment, the electronic component 6 is a passive component such as a capacitor, a resistor, or an inductor. The electronic component 7 is an active component such as an IC (integrated circuit). The electronic component 6 is surface-mounted with solder or the like on a land electrode (conductor 5) formed on the surface of the circuit board 4. The electronic component (IC) 7 is mounted on a land electrode (conductor 5) on the surface of the circuit board 4. Moreover, the electronic component (IC) 7 has a bare chip and a wire bonding in which a circuit pattern is formed inside the resin package. The conductor 5 is at least partially disposed between the circuit board 4 and the

electronic components

6 and 7 as land electrodes of the

electronic components

6 and 7. It is desirable to arrange the land electrodes so as to overlap with half or more of the bottom areas of the

electronic components

6 and 7. Moreover, it is desirable to arrange the conductor 5 so as to overlap with a plurality of

electronic components

6 and 7 arranged on the circuit board 4 as ground electrodes extending in a planar shape.

The circuit board 4 on which the

electronic components

6 and 7 are mounted is disposed in the space of the coil antenna 3. That is, the circuit board 4 is substantially accommodated in the space of the coil antenna 3. Note that the circuit board 4 may not be completely accommodated in the space of the coil antenna 3 and may partially protrude. Even in this case, the circuit board 4 is disposed in the opening of the coil antenna 3 when the coil antenna 3 is viewed in plan in the winding axis direction of the coil conductor 2. In the present embodiment, as described above, the opening of the coil antenna 3 is square, and the circuit board 4 has either a long side or a short side of the circuit board 4 on the diagonal of the square of the opening as shown in FIG. Are arranged so as to substantially follow. Further, either the long side or the short side of the circuit board 4 is disposed so as to overlap the center of gravity of the opening of the coil antenna 3. Note that the center of gravity here considers only the shape.

As shown in FIG. 4B, the circuit board 4 has a main surface of the circuit board 4 and a normal direction X to the main surface with respect to the winding axis direction Y of the coil conductor 2 of the coil antenna 3. The coil antenna 3 is housed in a space inclined by 45 degrees.

The antenna device 100 according to the first embodiment having the above-described structure has the following characteristics.

First, in the antenna device 100, the circuit board 4 on which the

electronic components

6 and 7 are mounted fits in the opening of the coil antenna 3 when viewed in plan in the winding axis direction Y of the coil conductor 2, and the coil antenna 3 Is contained in the space. Therefore, it is not necessary to prepare a separate space for accommodating the circuit board 4 and the size is reduced.

As shown in FIG. 3, the antenna device 100 has a square opening in the coil antenna 3 and a side of the circuit board 4 approximately along a diagonal line when viewed in a plan view. It is arranged to overlap the center of gravity.

As a result, in the antenna device 100, the conductor pattern of the circuit board 4, the

electronic components

6 and 7, the bare chip and the wire bonding of the electronic component 7 are not separated from the coil conductor 2 of the coil antenna 3 and are separated from each other. Has been placed. Further, the conductor pattern of the circuit board 4, the

electronic components

6 and 7, and the wire bonding of the electronic component 7 are less likely to be parallel to the portion of the coil conductor 2 closest to the circuit board 4. That is, the conductor pattern of the circuit board 4 and the

electronic components

6 and 7 are often arranged in parallel to the sides of the circuit board 4, but in this embodiment, the circuit board 4 and the coil conductor 2 are arranged. Since they are arranged at an angle (not parallel), as a result, the conductor pattern of the circuit board 4, the

electronic components

6 and 7, and the coil conductor 2 are hardly parallel. Further, since the corner of the circuit board 4 is closest to the coil conductor 2, the area of the circuit board 4 adjacent to the coil conductor 2 can be reduced.

In the antenna device 100, the conductor pattern of the circuit board 4, the

electronic components

6 and 7, and the coil conductor 2 of the coil antenna 3 are not easily coupled by an electric field, a magnetic field, or an electromagnetic field (an electric field and a magnetic field). ing. Therefore, the malfunction of the antenna device 100 due to unnecessary coupling is suppressed.

Furthermore, in the antenna device 100, as shown in FIG. 4B, the main surface of the circuit board 4 and the normal direction X to the main surface are inclined with respect to the winding axis direction Y of the coil conductor 2 of the coil antenna 3. In the state, the circuit board 4 is accommodated in the space of the coil antenna 3.

As a result, the antenna device 100 includes the circuit board 4 whose main surface is inclined with respect to the winding axis direction Y of the coil conductor 2 of the coil antenna 3, and is shielded by the conductor 5 of the circuit board 4. The magnetic flux MF (shown by a solid line and a broken line in FIG. 4B) prevents the

electronic components

6 and 7 from interlinking. What is indicated by a broken line is a suppressed magnetic flux. Moreover, since the normal direction X with respect to the main surface of the circuit board 4 is inclined with respect to the winding axis direction Y, the transmission efficiency of the coil antenna 3 due to the conductor 5 of the circuit board 4 blocking the magnetic flux MF of the coil antenna. The decline of is kept small. Therefore, the antenna device 100 is suppressed from malfunctioning and a decrease in transmission efficiency.

In the present embodiment, the normal direction X with respect to the main surface of the circuit board 4 is inclined 45 degrees with respect to the winding axis direction Y of the coil conductor 2, but this inclination can be changed as appropriate. . However, if the inclination is too large, the effect of blocking the magnetic flux MF of the coil antenna 3 by the conductor 5 of the circuit board 4 is reduced. On the other hand, if the inclination is too small, the influence of the conductor 5 of the circuit board 4 blocking the magnetic flux of the coil antenna 3 increases, and the transmission efficiency of the coil antenna 3 decreases. Therefore, the inclination of the normal direction X with respect to the main surface of the circuit board 4 with respect to the winding axis direction Y of the coil conductor 2 is made as small as possible, and the coil antenna 3 is viewed in plan in the winding axis direction Y of the coil conductor 2. In some cases, it is desirable that at least the center of gravity of the

electronic components

6 and 7 is placed inside the circuit board 4. Note that the center of gravity here considers only the shape. Further, if the outer shapes of the

electronic components

6 and 7 are accommodated in the circuit board 4, interference between the magnetic flux MF and the

electronic components

6 and 7 is further suppressed.

Furthermore, the inclination of the main surface of the circuit board 4 with respect to the winding axis direction Y of the coil conductor 2 is smaller than the inclination of the diagonal of the cube formed by the opening of the coil conductor 2 with respect to the winding axis direction Y of the coil conductor 2. Is desirable. Here, the diagonal line of the space formed by the coil conductor 2 is, for example, a line connecting the upper left portion and the lower right portion of the coil conductor in FIG.

[Second embodiment: Non-contact power transmission device (power supply device)]
Using the antenna device 100 according to the first embodiment, a non-contact power transmission device (power supply device) 200 according to the second embodiment was manufactured.

The non-contact power transmission apparatus 200 has the same equivalent circuit as the non-contact power transmission apparatus 300 disclosed in Patent Document 1 shown in FIG. Therefore, FIG. 5 is used in the description of this embodiment.

The non-contact power transmission device 200 includes a power transmission device and a power reception device. In the equivalent circuit of FIG. 5, the left half corresponds to the power transmission device and the right half corresponds to the power reception device.

In the non-contact power transmission apparatus 200, the antenna apparatus 100 according to the first embodiment is used for both the power transmission side antenna Lp of the power transmission apparatus and the power reception side antenna Ls of the power reception apparatus.

Since the non-contact power transmission device 200 uses the antenna device 100 that is small in size and prevents malfunction and reduction in transmission efficiency for the power transmission side antenna Lp and the power reception side antenna Ls, the power transmission device and the power reception device are Each of them is small in size so that malfunction and reduction in transmission efficiency are suppressed.

The antenna device 100 according to the first embodiment and the non-contact power transmission device 200 according to the second embodiment have been described above. However, the present invention is not limited to the contents described above, and various modifications can be made in accordance with the spirit of the invention.

For example, in the antenna device 100, the opening of the coil antenna 3 is square. However, as described above, if the circuit board 4 is arranged along a diagonal line, the opening is replaced with another opening. It may be a polygon or a regular polygon. If the opening of the coil antenna 3 is a polygon or a regular polygon, the main surface of the circuit board 4 and the normal direction X to the main surface are in relation to the winding axis direction Y of the coil conductor 2 of the coil antenna 3. It does not have to be tilted. The normal direction X to the main surface of the circuit board 4 may be parallel or perpendicular to the winding axis direction Y of the coil conductor 2 of the coil antenna 3. Alternatively, it may be a circle or an ellipse.

In the antenna device 100, the opening of the coil antenna 3 may be polygonal or regular polygonal, but the main surface of the circuit board 4 and the normal direction X with respect to the main surface are those of the coil conductor 2 of the coil antenna 3. The shape of the coil opening such as a circle or an ellipse is not limited as long as it is inclined with respect to the winding axis direction Y.

Further, the material and shape of each element constituting the antenna device 100 are also arbitrary. For example, in the antenna device 100, a nichrome wire is used for the coil conductor 2, but a copper wire or the like may be used instead.

Also, the type, shape, arrangement, and the like of the conductor 5 that is formed on the circuit board 4 and that extends in the plane direction are arbitrary, and are not limited to the above-described contents. For example, the conductor 5 may be formed in the circuit board 4 over a plurality of layers.

Furthermore, the type, number, size, and the like of the

electronic components

6 and 7 mounted on the circuit board 4 are arbitrary and are not limited to the above-described contents.

In the non-contact power transmission apparatus 200, the antenna apparatus 100 according to the first embodiment is used for both the power transmission side antenna Lp and the power reception side antenna Ls. However, the antenna apparatus 100 may be used for either one. good.

Furthermore, the equivalent circuit of the non-contact power transmission apparatus of the present invention is also arbitrary and is not limited to that shown in FIG.

Furthermore, in the present invention, the antenna device used in the non-contact power transmission device is illustrated, but the present invention can be similarly applied to a near field communication (NFC) antenna device using magnetic field coupling.

DESCRIPTION OF SYMBOLS 1 ... Case 2 ... Coil conductor 3 ... Coil antenna 4 ... Circuit board 5 ... Conductor (Ground electrode, wiring electrode, land electrode, etc.)
6. Electronic components (passive components such as capacitors, resistors, inductors)
7 ... Electronic parts (IC and other active parts)
X: Normal direction with respect to the main surface of the circuit board 4 Y: Winding axis direction MF of the coil conductor 2 MF ... Magnetic flux Lp ... Power transmission side antenna Ls ... Power reception side antenna 100 ... Antenna Device 200 ... Non-contact power transmission device (power supply device)

Claims

A coil antenna having a coil conductor wound around a winding axis and stacked in the direction of the winding axis to form a space inside;
A circuit board disposed in a space formed by the coil conductor;
With
When the coil antenna is viewed in plan in the winding axis direction of the coil conductor, the opening surface of the coil antenna is polygonal, and the circuit board is disposed so as to follow the polygonal diagonal line .
A coil antenna having a coil conductor wound around a winding axis and stacked in the direction of the winding axis to form a space inside;
A circuit board disposed in a space formed by the coil conductor;
With
The circuit board is an antenna device in which a main surface and a normal line of the main surface are both inclined with respect to a winding axis direction of the coil conductor.
A coil antenna having a coil conductor wound around a winding axis and stacked in the direction of the winding axis to form a space inside;
A circuit board disposed in a space formed by the coil conductor;
With
When the coil antenna is viewed in plan in the winding axis direction of the coil conductor, the opening surface of the coil antenna is polygonal, and the circuit board is disposed along the diagonal line of the polygon,
The circuit board is an antenna device in which a main surface and a normal line of the main surface are both inclined with respect to a winding axis direction of the coil conductor.
The antenna device according to claim 1 or 3, wherein the polygon is a rectangle.
The antenna device according to claim 4, wherein the rectangle is a square.
Electronic components are mounted on the circuit board,
4. The antenna device according to claim 2, wherein a center of gravity of an outer shape of the electronic component is included in an outer edge of the circuit board when the coil antenna is viewed in plan in the winding axis direction of the coil conductor. .
The antenna device according to claim 6, wherein when the coil antenna is viewed in a plan view in the winding axis direction of the coil conductor, the entire outer shape of the electronic component is included in the outer edge of the circuit board.
The antenna device according to any one of claims 1 to 7, wherein the circuit board has a conductor pattern on at least one of an inside and a surface thereof.
A power supply device using the antenna device according to any one of claims 1 to 8 as at least one of a power transmission side antenna and a power reception side antenna in a non-contact power transmission system.