JP6318826B2 - Antenna device - Google Patents

Description

  The present invention relates to an antenna device, and more particularly to an antenna device suitable for NFC (Near Field Communication).

  In recent years, RFID (Radio Frequency Identification) systems are installed in portable electronic devices such as smartphones, and antennas for short-range wireless communication with readers / writers, etc. are installed as communication means. ing.

  On the other hand, in order to protect the built-in circuit from external noise and prevent unnecessary radiation of noise generated in the device, the mobile electronic device is provided with a metal shield. Recently, considering the reduction in thickness, weight, durability against impacts such as dropping, and design, the case of portable electronic devices has been changed from resin to metal, and the number of cases that also serve as a metal shield has increased. Yes. However, since a metal shield generally prevents radio waves, when an antenna is provided, it is necessary to provide it at a position that does not overlap with the metal shield. When the metal shield is provided over a wide range, the arrangement of the antenna becomes a problem.

  In order to solve the above problem, for example, the antenna devices disclosed in Patent Documents 1 to 3 form an opening in the conductor layer and a slit connecting the opening and the outer edge, and the inner diameter portion is open. The antenna coil is arranged so as to overlap the part. According to this antenna device, the current flows through the conductor layer so as to block the magnetic field generated by the current flowing through the coil conductor, and the current flowing around the opening of the conductor layer passes through the periphery of the slit due to the edge effect. Current also flows around the conductor layer. Thereby, a magnetic field is also generated from the conductor layer, and the conductor layer largely circulates the magnetic flux, so that the communication distance between the antenna device and the counterpart antenna can be increased. That is, the conductor layer can function as an accelerator that increases the communication distance of the antenna coil.

Japanese Patent No. 4687832 JP 2002-111363 A JP 2013-162195 A

  However, the conventional antenna device described above has a problem in that it is necessary to form an opening and a slit in the conductor layer, which is a limitation in laying out the antenna coil. For example, when the opening cannot be formed at a desired position due to design restrictions, or when the opening can be formed but the slit is not allowed, the antenna device is configured. There is a problem that can not be. The same problem occurs when the opening for exposing the lens of the camera module cannot be used as the opening of the antenna coil.

  Accordingly, an object of the present invention is to provide an antenna device capable of extending the communication distance of an antenna coil even when a conductor layer provided on the portable electronic device side is not provided with an opening or a slit.

  In order to solve the above problems, an antenna device according to the present invention includes a substrate, a loop-shaped or spiral-shaped antenna coil formed on the substrate, and a first portion overlapping the first portion of the antenna coil in plan view. And a second metal layer overlapping the second part of the antenna coil different from the first part in a plan view, the first metal layer and the second metal layer comprising: The antenna coil is disposed on both sides of the center of the inner diameter portion of the antenna coil in plan view, and the slit formed between the first metal layer and the second metal layer is formed on the antenna coil. It overlaps with an inner diameter part by planar view, At least one of the said 1st and 2nd metal layer is formed on the said board | substrate with the said antenna coil, It is characterized by the above-mentioned.

  According to the present invention, at least one of the first and second metal layers is formed on the substrate together with the antenna coil, and the slit formed by the first and second metal layers overlaps the inner diameter portion of the antenna coil. Therefore, the communication distance of the antenna coil can be extended even when the opening or slit is not provided in the conductor layer provided on the portable electronic device side. In particular, since no dedicated support substrate or adhesive layer is interposed between the first and second metal layers and the antenna coil, the distance between the first and second metal layers and the antenna coil can be reduced. Therefore, the magnetic coupling between the magnetic flux generated by the antenna coil and the metal layer can be strengthened, and the communication distance of the antenna can be extended. Furthermore, since the antenna coil is formed with the first and second metal layers on a substrate different from the substrate, the step of attaching the first and second metal layers to the antenna coil becomes unnecessary. The manufacturing process of the antenna device can be simplified.

  In the present invention, it is preferable that both the first and second metal layers are formed on the substrate together with the antenna coil. According to this configuration, the antenna coil can be brought close to both the first and second metal layers, and the communication distance of the antenna can be reliably extended.

  In the present invention, it is preferable that the first metal layer is formed on the substrate together with the antenna coil, and the second metal layer is a constituent member of a housing in which the antenna device is accommodated. . According to this configuration, the second metal layer can be formed using the metal body on the housing side, and the material cost can be reduced and the component layout can be made more efficient.

  In the present invention, the antenna coil comprises a combination of a first pattern formed on one main surface of the substrate and a second pattern formed on the other main surface of the substrate. The metal layer is formed on the other main surface of the substrate, the second metal layer is provided to face the other main surface of the substrate, and the second pattern is It is preferable that the second metal layer is provided at a position overlapping with the second metal layer in plan view. According to this configuration, since the formation position of the second pattern and the first metal layer formed on the other main surface of the substrate do not overlap each other, the antenna coil and the first metal layer are efficiently laid out on the substrate. can do.

  The antenna device according to the present invention preferably further includes a metal body provided at a position overlapping the antenna coil in plan view, and a magnetic sheet provided between the antenna coil and the metal body. According to this configuration, the magnetic path of the magnetic flux loop interlinking with the antenna coil can be secured, and the influence of the metal body can be reduced.

  The antenna device according to the present invention preferably further includes a central metal layer provided at a central portion of the inner diameter portion of the antenna coil in plan view. According to this configuration, two slits can be provided between the first and second metal layers, and the communication distance of the antenna coil can be extended as compared with the case where one slit is provided.

  The antenna device according to the present invention includes a third metal layer overlapping the third portion of the antenna coil different from the first and second portions in plan view, and the antenna different from the first to third portions. A fourth metal layer overlapping the fourth portion of the coil in plan view, wherein the third metal layer and the fourth metal layer are formed on the inner diameter portion of the antenna coil in plan view. It is preferable that they are respectively arranged on both sides of the center. The magnetic flux penetrating the inner diameter portion of the antenna coil passes through the region surrounded by the first to fourth metal layers, so that the passage of the magnetic flux can be concentrated on the inner diameter portion, thereby extending the communication distance of the antenna. be able to. Furthermore, by additionally providing the third and fourth metal layers, it is possible to increase the loop size of the magnetic flux while suppressing the loss of magnetic flux interlinking with the antenna coil, and to reliably extend the communication distance of the antenna. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, even when the opening part and slit are not provided in the conductor layer provided in the portable electronic device side, the antenna apparatus which can extend the communication distance of an antenna coil can be provided.

FIG. 1 is a plan view showing the configuration of the antenna device according to the first embodiment of the present invention. In particular, FIG. 1B shows the antenna coil transparently viewed from the same direction as FIG. It is a figure. FIG. 2 is a cross-sectional view of the antenna device along line YY ′ of FIG. FIG. 3 is a plan view for explaining the action of the first and second metal layers on the antenna coil. FIG. 4 is a cross-sectional view for explaining the action of the first and second metal layers on the antenna coil. FIG. 5 is a plan view showing the configuration of the antenna device according to the second embodiment of the present invention. FIG. 6 is a cross-sectional view showing the configuration of the antenna device according to the second embodiment of the present invention. FIG. 7 is a plan view showing the configuration of the antenna device according to the third embodiment of the present invention. FIG. 8 is a plan view showing the configuration of the antenna device according to the fourth embodiment of the present invention. FIG. 9 is a cross-sectional view showing the configuration of the antenna device according to the fourth embodiment of the present invention. FIG. 10 is a plan view showing the configuration of the antenna device according to the fifth embodiment of the present invention. FIG. 11 is a plan view showing the configuration of the antenna device according to the sixth embodiment of the present invention. In particular, FIG. 11B shows the antenna coil transparently viewed from the same direction as FIG. It is a figure. FIG. 12 is a cross-sectional view of the antenna device taken along line YY ′ of FIGS.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a plan view showing the configuration of the antenna device according to the first embodiment of the present invention. In particular, FIG. 1B shows the antenna coil transparently viewed from the same direction as FIG. It is a figure. FIG. 2 is a cross-sectional view of the antenna device along the line YY ′ in FIG.

  As shown in FIGS. 1A, 1B, and 2, this antenna device 1 includes a substrate 10, a spiral antenna coil 11 formed on the substrate 10, and the antenna coil 11 in a plan view. 1st and 2nd metal layer 12A, 12B provided so that it might overlap, and magnetic sheet 14 provided on the opposite side to the 1st and 2nd metal layer 12A, 12B seeing from antenna coil 11 ing.

  The substrate 10 is a flexible substrate made of, for example, a PET resin, and has a planar size of, for example, 40 × 50 mm and a thickness of about 30 μm. The antenna coil 11 has a substantially rectangular spiral pattern 11 a and is mainly formed on one main surface 10 a (lower surface) of the substrate 10. The antenna coil 11 may be formed by plating, or may be formed by etching (patterning) a metal layer previously formed on the entire surface of the substrate 10.

  Both ends of the spiral pattern 11a of the antenna coil 11 are drawn out to the edge of the substrate 10 by lead portions 11c and 11d. In particular, the inner peripheral end of the spiral pattern 11a is outside the loop via a bridge portion 11e crossing the spiral loop. Has been drawn to. Both ends of the antenna coil 11 are connected to, for example, a main circuit board. The connection method is not particularly limited. For example, the lead portions 11c and 11d may be extended together with the flexible material substrate 10 to be connected to the main circuit substrate, or may be connected using power supply pins. is there.

  In the present embodiment, the bridge portion 11e is formed on the spiral pattern 11a formed on one main surface 10a of the substrate 10 via an insulating film such as PET. In this case, the two-layer structure of the metal film is partially formed on the one main surface 10a side of the substrate 10. One end and the other end of the bridge portion 11e are connected to the inner peripheral end of the spiral pattern 11a and one end of the lead portion 11d through through-hole conductors 11f and 11f that penetrate the insulating film. Since the antenna coil 11 is formed only by the pattern formed on the one main surface 10a of the substrate 10, the entire area of the other main surface 10b of the substrate 10 is formed on the first and second metal layers 12A and 12B. It can be.

  In the present embodiment, the first and second metal layers 12A and 12B are so-called solid patterns, and are formed on the other main surface 10b (upper surface) of the substrate 10. The first and second metal layers 12A and 12B may be formed by plating, or may be formed by etching a metal layer previously formed on the entire surface of the substrate 10. In the case of plating, the first and second metal layers 12A and 12B can be formed simultaneously with the antenna coil 11. In the case of etching the metal layer, the first and second metal layers 12A and 12B having a thickness different from that of the antenna coil 11 can be formed. In any case, since the first and second metal layers 12A and 12B are not bonded to the substrate surface and no adhesive (adhesive layer) is interposed, the first and second metal layers 12A and 12B are not attached. It can be brought close to the antenna coil 11, and the communication distance of the antenna can be extended by strengthening the magnetic coupling between the two.

  A metal body 15 is provided farther than the magnetic sheet 14 when viewed from the antenna coil 11. The metal body 15 is a battery case of a portable electronic device such as a smartphone on which the antenna device 1 is mounted. By interposing the magnetic sheet 14 between the antenna coil 11 and the metal body 15, it is possible to suppress the influence of the metal body 15 on the antenna coil 11 and increase the inductance, thereby improving the antenna characteristics. it can.

  The first metal layer 12A is provided on one end side of the substrate 10 in the Y direction (first width direction), and the second metal layer 12B is provided on the other end side of the substrate 10 in the Y direction. The first metal layer 12A and the second metal layer 12B are disposed on both sides of the center of the inner diameter portion 11b of the antenna coil 11 in plan view.

  A slit SL having a constant width is provided between the first metal layer 12A and the second metal layer 12B, and the first and second metal layers 12A and 12B are electrically insulated and separated by the slit SL. ing. The width of the slit SL is preferably narrower than the width of the inner diameter portion 11b of the antenna coil 11 in the same direction. The slit SL is provided at a position in the center in the width direction of the substrate 10 and across the inner diameter portion 11 b of the antenna coil 11. That is, the antenna coil 11 is laid out such that the inner diameter portion 11b overlaps the slit SL in plan view. It is preferable that a portion substantially parallel to the slit SL of the antenna coil 11 overlaps the first and second metal layers 12A and 12B in plan view.

  3 and 4 are views for explaining the action of the first and second metal layers 12A and 12B on the antenna coil 11, wherein FIG. 3 is a plan view and FIG. 4 is a cross-sectional view.

  As shown in FIGS. 3 and 4, when a counterclockwise current Ia flows through the antenna coil 11, a magnetic flux φ penetrating the inner diameter portion 11b of the antenna coil 11 is generated, and this magnetic flux φ is the first and second magnetic fluxes. It passes through the slit SL between the metal layers 12A and 12B and is linked to each of the first and second metal layers 12A and 12B. On the other hand, a current generated by a magnetic flux in a direction to cancel the magnetic flux flows through the first metal layer 12A and the second metal layer 12B. This current is caused by the edge effect, and the first and second metal layers 12A. , 12B, the eddy current Ib along the outer periphery. The direction of the eddy current Ib is counterclockwise in the same manner as the current Ia flowing through the antenna coil 11.

  Here, the magnetic flux φ that has passed through the slit SL has the slit SL between the first metal layer 12A and the second metal layer 12B inside, and the outer edges of the first metal layer 12A and the second metal layer 12B. Try to make a detour through the path outside. As a result, the magnetic flux φ draws a relatively large loop, interlinks with the antenna coil of the reader / writer, and the antenna device 1 is magnetically coupled to the communication partner antenna. In particular, since the planar size of the outer periphery of the entire metal layer including the first metal layer 12A, the second metal layer 12B, and the slit SL is larger than the planar size of the antenna coil, a large loop magnetic field can be generated. Furthermore, since the magnetic sheet 14 is provided on the side opposite to the first and second metal layers 12A and 12B when viewed from the antenna coil 11, the magnetic path of the magnetic flux φ can be secured and the inductance can be increased. As a result, the antenna characteristics can be improved.

  As described above, in the antenna device 1 according to the present embodiment, the first metal layer 12A and the second metal layer 12B greatly circulate the loop of the magnetic flux φ of the antenna coil 11, and therefore the communication distance of the antenna device 1 Can be extended. Further, the first and second metal layers 12A and 12B are formed directly on the substrate 10, and no adhesive layer or the like is interposed between the substrate 10 and the first and second metal layers 12A and 12B. The distance between the antenna coil 11 and the first and second metal layers 12A and 12B can be reduced, and the communication distance can be reliably increased by strengthening the magnetic coupling between the two.

  5 and 6 are diagrams showing the configuration of the antenna device according to the second embodiment of the present invention. FIG. 5 is a plan view and FIG. 6 is a cross-sectional view.

  As shown in FIGS. 5 and 6, the antenna device 2 is characterized in that only the first metal layer 12 </ b> A is formed on the substrate 10, and the second metal layer 12 </ b> B is provided separately from the substrate 10. There is in point. Specifically, the second metal layer 12B is provided above the other main surface 10b of the substrate 10 and at a position facing the other main surface 10b. The second metal layer 12B is preferably a constituent member of a housing of a portable electronic device such as a smartphone in which the antenna device 1 is accommodated. The second metal layer 12B may also be formed on a support substrate different from the housing. The width W3 in the X direction of the second metal layer 12B is wider than the width W4 in the X direction of the substrate 10.

  In the present embodiment, the bridge portion 11 e for pulling out the inner peripheral end of the antenna coil 11 to the outside of the loop is formed on the other main surface 10 b of the substrate 10. One end and the other end of the bridge portion 11e are connected to the inner peripheral end of the spiral pattern 11a and one end of the lead portion 11d via through-hole conductors 11f and 11f, respectively. Since the antenna coil 11 is formed only by a pattern directly formed on one and the other main surfaces 10a and 10b of the substrate 10, there is no need to overlap an additional metal layer in order to form the bridge portion 11e. Is easy. In particular, since the second metal layer 12B is not formed on the substrate 10, the bridge portion 11e can be provided at a position overlapping the second metal layer 12B in plan view, and the bridge portion 11e can be easily laid out. be able to.

  In this manner, the antenna coil 11 is formed on the spiral pattern 11a and the lead portions 11c and 11d (first pattern) formed on the one main surface 10a of the substrate 10 and the other main surface 10b of the substrate 10. It consists of a combination with the bridge portion 11e (second pattern), and the bridge portion 11e is provided at a position overlapping the second metal layer 12B in plan view. According to this configuration, the antenna coil 11 and the first and second metal layers 12A and 12B can be laid out efficiently.

  In the present embodiment, the slit SL is formed by the combination of the first metal layer 12A on the substrate 10 side and the second metal layer 12B on the housing side, and the accelerator for the antenna coil 11 is configured. The same effects as those of the embodiment can be obtained. In addition, by using a metal body on the housing side, the preparation of a dedicated metal layer can be omitted, so that material costs can be reduced and component layout efficiency can be improved. By utilizing the size of the second metal layer 12B, it is possible to increase the loop size of the magnetic flux and contribute to the improvement of the communication distance.

  FIG. 7 is a plan view showing the configuration of the antenna device according to the third embodiment of the present invention.

  As shown in FIG. 7, the feature of the antenna device 3 is a modification of the antenna device 2 according to the second embodiment, and the width W1 in the X direction (second direction) of the first metal layer 12A. Is narrower than the substrate 10 and is set to be not more than the width W2 in the X direction of the inner diameter portion 11b of the antenna coil 11, in particular. Therefore, the planar size of the first metal layer 12A is smaller than that of the second metal layer 12B. Other configurations are the same as those of the second embodiment.

  The first metal layer 12A overlaps the first portion P1 of the antenna coil 11 in plan view. Further, the second metal layer 12B has an overlap with the second portion P2 of the antenna coil 11 facing the first portion P1 across the inner diameter portion 11b of the antenna coil 11 in plan view. The area of the first portion P1 of the antenna coil 11 covered with the first metal layer 12A is smaller than the area of the second portion P2 of the antenna coil 11 covered with the second metal layer 12B.

  As described above, when the width W1 of the first metal layer 12A is equal to or smaller than the width W2 of the inner diameter portion 11b of the antenna coil, the coil pattern does not overlap with the metal layer more than necessary, thereby reducing the loss of magnetic flux. This can extend the communication distance. Further, by reducing the planar size of the first metal layer 12A, the size of the substrate 10 can be reduced, and the degree of freedom of layout in the portable electronic device can be increased. Furthermore, by reducing the planar size of the first metal layer 12A, the stray capacitance between the first metal layer 12A and the antenna coil 11 can be reduced, and the frequency matching of the antenna can be easily performed. Although the planar size of the first metal layer 12A is small, the planar size of the second metal layer 12B is large, so that the loop size of the magnetic flux can be increased by the second metal layer 12B.

  8 and 9 are diagrams showing a configuration of an antenna device according to the fourth embodiment of the present invention, in which FIG. 8 is a plan view and FIG. 9 is a cross-sectional view.

  As shown in FIGS. 8 and 9, the antenna device 4 is characterized in that it further includes a central metal layer 12 </ b> C provided in the central portion of the inner diameter portion 11 b of the antenna coil 11 in plan view. The central metal layer 12C has an elongated rectangular pattern parallel to the slit SL, and is disposed at the center in the width direction of the slit SL, and is sandwiched between the first metal layer 12A and the second metal layer 12B. . As a result, the slit SL is divided, and the first and second slits SL1 and SL2 are formed. The inner diameter portion 11b of the antenna coil 11 overlaps the two slits SL1 and SL2 in plan view. Other configurations are the same as those of the third embodiment.

  Although not particularly limited, the widths of the two slits SL1 and SL2 are preferably the same. The width in the Y direction of the central metal layer 12C is preferably wider than the widths of the slits SL1 and SL2. However, if the width is too large, the widths of the slits SL1 and SL2 become extremely narrow. There is. Note that the width of the slit SL before the division needs to be narrower than the width of the inner diameter portion 11 b of the antenna coil 11.

  The antenna device 4 according to the present embodiment can achieve an effect equal to or greater than that of the third embodiment. That is, the combination of the first and second metal layers 12A and 12B and the central metal layer 12C greatly circulates the magnetic flux of the antenna coil 11, so that the communication distance of the antenna device can be extended. This embodiment is particularly effective when the metal body 15 is provided relatively far from the antenna coil 11. That is, the central metal layer 12C is provided in a configuration in which the position of the metal body 15 located on the opposite side of the antenna coil 11 with respect to the magnetic sheet 14 is relatively far from the antenna coil 11, and the slit SL is formed into two slits SL1 and SL2. When divided, the communication distance can be reliably extended as compared with the case where the central metal layer 12C is not provided.

  FIG. 10 is a plan view showing the configuration of the antenna device according to the fifth embodiment of the present invention.

  As shown in FIG. 10, the antenna device 5 is characterized by the third and fourth metal layers 12D and 12E formed on the substrate 10 together with the antenna coil 11, the first metal layer 12A and the central metal layer 12C. Furthermore, it is in the point to prepare. Other configurations are the same as those of the fourth embodiment.

  In the present embodiment, the third and fourth metal layers 12D and 12E are provided on one end side and the other end side in the X direction of the substrate 10, respectively. The third metal layer 12D and the fourth metal layer 12E are provided. Are arranged on both sides of the center of the inner diameter portion 11b of the antenna coil 11 in plan view. The third metal layer 12D overlaps with the third portion P3 of the antenna coil 11 different from the first and second portions P1 and P2 in plan view, and the fourth metal layer 12E includes the first to second portions. It overlaps with the 4th part P4 of the antenna coil 11 different from 3 parts P1-P3 by planar view.

  According to the present invention, in addition to the effects of the invention according to the fourth embodiment, the magnetic flux of the antenna coil 11 can be further increased, and the antenna characteristics can be further improved.

  FIG. 11 is a plan view showing the configuration of the antenna device according to the sixth embodiment of the present invention. In particular, FIG. 11 (b) is a view seen transparently from the same direction as FIG. 11 (a). is there. FIG. 12 is a cross-sectional view taken along line YY ′ of FIGS. 11 (a) and 11 (b).

FIG. 11 (a), the as shown in (b) and FIG. 12, the antenna device 6, one half 11a ₁ of the antenna coil 11 is formed on one main surface (lower surface) 10a of the substrate 10, the remaining The half 11a ₂ is formed on the other main surface (upper surface) 10b of the substrate 10, and they are connected via a through-hole conductor 11g penetrating the substrate 10 to form one continuous spiral pattern. Each of the end portions of the plurality of half-loop patterns constituting the half half 11a ₁ of the antenna coil 11 corresponds to the corresponding end portion of the plurality of half-loop patterns constituting the remaining half 11a ₂ of the antenna coil via the through-hole conductor 11g. It is connected to the.

On the other hand, of the first and second metal layers 12A and 12B, the first metal layer 12A is formed on one main surface (lower surface) 10a of the substrate 10, and the second metal layer 12B is formed on the substrate 10. It is formed on the other main surface 10b. The first metal layer 12A overlaps the halves 11a ₁ of the antenna coil 11, the second metal layer 12B overlaps the other half 11a ₂ of 11 of the antenna coil.

  As described above, the antenna device 5 according to the present embodiment can achieve the same operational effects as the antenna device 1 according to the first embodiment. That is, in the antenna device 5 according to the present embodiment, the first metal layer 12A and the second metal layer 12B greatly circulate the magnetic flux loop of the antenna coil 11, so that the communication distance of the antenna can be extended. In particular, since the first and second metal layers 12A and 12B are formed directly on the substrate surface and no adhesive layer or the like is interposed, the antenna coil 11 and the first and second metal layers 12A and 12B The distance can be reduced, and the communication distance of the antenna can be extended by strengthening the magnetic coupling between the two.

  The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention, and it goes without saying that these are also included in the present invention. .

  For example, in the first embodiment, the bridge portion 11e of the antenna coil 11 is provided to overlap the spiral pattern on one main surface 10a of the substrate 10, but the bridge portion 11e is the other main surface of the substrate 10. It may be provided at a position on the surface 10b side and avoiding the formation area of the first and second metal layers 12A and 12B, for example, in the slit SL between the first and second metal layers 12A and 12B. Since the bridge portion 11e is not a pattern formed in a wide range but is a small pattern that crosses the spiral pattern, the influence on the magnetic flux φ passing through the inner diameter portion 11b of the antenna coil 11 is limited.

  Further, in each of the above embodiments, the antenna coil 11 is configured with a spiral pattern of several turns, but may be a loop pattern of less than one turn. That is, the antenna coil 11 may be a loop or spiral planar coil pattern.

1 to 6 Antenna device 10 Substrate 10a One main surface 10b of the substrate The other main surface 11 of the substrate Antenna coil 11a Spiral pattern 11a _One half of one antenna coil 11a _Two remaining half of the antenna coil

11b Inner diameter portion 11c, 11d Lead portion 11e Bridge portion 11f, 11g Through-hole conductor 12A First metal layer 12B Second metal layer 12C Central metal layer 12D Third metal layer 12E Fourth metal layer 14 Magnetic sheet 15 Metal Body P1 First part of antenna coil P2 Second part of antenna coil P3 Third part of antenna coil P4 Fourth part of antenna coil SL, SL1, SL2 Slit

Claims (7)

A substrate,
A loop or spiral antenna coil formed on the substrate;
A first metal layer overlapping the first portion of the antenna coil in plan view;
A second metal layer overlapping the second portion of the antenna coil different from the first portion in plan view;
The first metal layer and the second metal layer are respectively disposed on both sides of the center of the inner diameter portion of the antenna coil in plan view,
The slit formed between the first metal layer and the second metal layer overlaps the inner diameter portion of the antenna coil in plan view,
The first metal layer is formed on the substrate together with the antenna coil,
The antenna device, wherein the second metal layer is disposed farther than the first metal layer when viewed from the antenna coil . The entire surface of the first metal layer overlaps the substrate in plan view;
  2. The antenna device according to claim 1, wherein a part of the second metal layer does not overlap the substrate in a plan view and the remaining part overlaps the substrate. Prior Symbol second metal layer, which is a component of the housing in which the antenna device is housed, an antenna device according to claim 1. The antenna coil is
A combination of a first pattern formed on one main surface of the substrate and a second pattern formed on the other main surface of the substrate;
The first metal layer is formed on the other main surface of the substrate;
The second metal layer is provided to face the other main surface of the substrate,
The antenna device according to claim 3, wherein the second pattern is provided at a position overlapping with the second metal layer in plan view. A metal body provided at a position overlapping the antenna coil in plan view;
The antenna device according to claim 1, further comprising a magnetic sheet provided between the antenna coil and the metal body.   The antenna device according to any one of claims 1 to 5, further comprising a central metal layer provided at a central portion of the inner diameter portion of the antenna coil in a plan view. A third metal layer overlapping in plan view with a third portion of the antenna coil different from the first and second portions;
A fourth metal layer overlapping the fourth portion of the antenna coil different from the first to third portions in plan view;
The said 3rd metal layer and the said 4th metal layer are each arrange | positioned on both sides across the said center of the said internal-diameter part of the said antenna coil by planar view. The antenna device according to 1.