JP2017135481A - Coil device and wireless IC device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement a small coil device having a desired inductance value, and capable of reducing the DC resistance.SOLUTION: A coil device CD1 includes large diameter loops BL1, BL2, BL3, BL4 having a winding axis in a first direction (Y axis direction), small diameter loops SL1, SL2, SL3, SL4 having a winding axis in the Y axis direction, and a wiring board having a first principal surface parallel with the Y axis direction. The large diameter loops BL1, BL2, BL3, BL4 are in conduction with the small diameter loops SL1, SL2, SL3, SL4, and are constituted to include a large diameter bridge-like conductor placed on the outside of the wiring board. The small diameter loops SL1, SL2, SL3, SL4 are constituted to include a small diameter bridge-like conductor mounted on the first principal surface. The large diameter bridge-like conductor and small diameter bridge-like conductor are non-parallel with the first principal surface (XY plane). The small diameter bridge-like conductor is placed on the inside of the external diameter of large diameter loops BL1, BL2, BL3, BL4, when viewing from the Y axis direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a coil device used in a short-range wireless communication apparatus such as an RFID (Radio Frequency Identification) tag, and a wireless IC device including the coil device.

  An HF band RFID tag is generally card-sized, but a small RFID tag with a small occupied area may be required for use in merchandise management or the like. As a small HF band RFID tag, an RFID tag having a shape as shown in Patent Documents 1 and 2 is known. These small RFID tags are RFID tags using a so-called sheet lamination method, in which a laminated coil antenna is built in a multilayer substrate and an RFIC chip is mounted on the multilayer substrate.

JP 2007-102348 A International Publication No. 2011/108340

  The inventors have found that the RFID tag as disclosed in Patent Documents 1 and 2 has the following problems in the process of developing the small RFID tag.

(A) The RFID tags shown in Patent Documents 1 and 2 are arranged at a position where the main surface of the RFIC chip intersects the central axis of the coil antenna. Therefore, an electrode (land pattern) for mounting the RFIC chip intersects with the winding axis of the coil antenna. As a result, the RFIC chip mounting electrode and the RFIC chip tend to hinder the formation of a magnetic field by the coil antenna. If the RFIC chip is arranged outside the coil opening, it becomes difficult to prevent the formation of the magnetic field, but the occupied area becomes large.

(B) In particular, when a coil antenna is manufactured by a sheet lamination method, it is necessary to consider sheet stacking error (stacking position accuracy) and flatness of the laminate, and increase the number of sheets stacked and the thickness of the coil pattern. There is a limit to film formation. Therefore, the inductance value obtained is limited, and it is particularly difficult to obtain a coil antenna with a small direct current resistance (DCR). Although it is possible to form a coil pattern so that the coil winding axis faces the sheet surface direction, in this case, it is difficult to increase the coil opening area due to the limit of the number of stacked sheets. Yes, it is difficult to obtain a coil antenna with a small DC resistance.

  An object of the present invention is to provide a small coil device having a desired inductance value and excellent electrical characteristics, particularly capable of reducing a direct current resistance, and a wireless IC device including the coil device. is there.

(1) The coil device of the present invention includes:
A large-diameter loop having a winding axis in the first direction and including a large-diameter bridge-shaped conductor;
A small-diameter loop having a winding axis along the first direction, and including a small-diameter bridge-like conductor disposed inside the outer diameter of the large-diameter loop as viewed from the first direction;
A wiring board having a first main surface and a second main surface that are at least partially disposed inside the large-diameter loop and are parallel to the first direction, as viewed from the first direction;
With
The large diameter loop is connected to the small diameter loop,
The large-diameter bridge-shaped conductor and the small-diameter bridge-shaped conductor are non-parallel to the first main surface,
The small-diameter bridge-shaped conductor is mounted on the first main surface,
The first end and the second end of the large-diameter bridge-shaped conductor are arranged outside the wiring board.

  In this configuration, since the first end and the second end of the large-diameter bridge-shaped conductor are not mounted on the wiring board, the land for mounting the first end and the second end of the large-diameter bridge-shaped conductor is provided on the wiring board. There is no need to form. Therefore, the large diameter bridge-shaped conductor and the small diameter bridge-shaped conductor can be arranged at a narrow pitch in the first direction. Therefore, with this configuration, the area occupied by the coil (particularly the dimension in the first direction) can be reduced for the number of turns.

  Further, in this configuration, at least a part of the large-diameter bridge-like conductor and the small-diameter bridge-like conductor constituting the coil device is constituted by a metal member. Therefore, the DCR of the large-diameter bridge-like conductor and the small-diameter bridge-like conductor can be reduced as compared with the case where the sintered metal body is formed by firing the conductive paste, or the thin film metal body is formed by etching the conductive thin film. And a low-loss coil device can be obtained.

(2) In the above (1), it is preferable that a resin member is further provided, and at least a part of the large-diameter loop, the small-diameter loop, and the wiring board is embedded in the resin member. With this configuration, at least a part of the large-diameter loop and at least a part of the small-diameter loop are protected by the resin member, so that the robustness of the entire coil device is enhanced.

(3) In the above (2), the wiring board may be disposed such that the first main surface is embedded inside the resin member and the second main surface is exposed from the resin member.

(4) In any one of (1) to (3), the large-diameter loop includes a large-diameter loop connecting conductor connected to a first end or a second end of the large-diameter bridge-shaped conductor, and the small-diameter The loop includes a small-diameter loop connection conductor connected to the first end or the second end of the small-diameter bridge-shaped conductor, and at least a part of the large-diameter loop connection conductor is inside the wiring board or the second main surface. Preferably, the small-diameter loop connection conductor is formed inside the wiring board or on the first main surface. In this configuration, the large-diameter loop connection conductor and the small-diameter loop connection conductor can be easily configured by using the conductor formed on the wiring board.

(5) In any one of (1) to (4), the large-diameter bridge-shaped conductor includes a first columnar metal portion and a second columnar metal portion that extend in a direction orthogonal to the first main surface, A diameter connecting conductor, wherein the large diameter connecting conductor connects between a first end of the first columnar metal portion and a first end of the second columnar metal portion, and the first columnar metal portion. It is preferable that the second columnar metal part is disposed outside the wiring board. With this configuration, the DCR of the large-diameter bridge-shaped conductor can be reduced as compared with a sintered metal body obtained by firing conductive paste, a thin film metal body obtained by etching a conductive thin film, etc. A low-loss coil device is obtained. In addition, with this configuration, for example, compared to the case where a plurality of base material layers having interlayer conductors are stacked to form a height-wise connection portion, the number of connection points can be reduced, and the electrical reliability of the coil device can be reduced. Rise.

(6) In any one of the above (1) to (5), the small-diameter bridge-shaped conductor is connected to a third columnar metal portion and a fourth columnar metal portion that extend in a direction orthogonal to the first main surface, and a small-diameter connection. The small-diameter connection conductor connects between a first end of the third columnar metal part and a first end of the fourth columnar metal part, and a second of the third columnar metal part. It is preferable that the end and the second end of the fourth columnar metal part are respectively mounted on the first main surface of the wiring board. With this configuration, since the DCR of the small-diameter bridge-shaped conductor can be reduced as compared with the case where the sintered metal body is formed by firing the conductive paste, or the thin film metal body is formed by etching the conductive thin film, the Q value is high and low. A lossy coil device is obtained. In addition, with this configuration, for example, compared to the case where a plurality of base material layers having interlayer conductors are stacked to form a height-wise connection portion, the number of connection points can be reduced, and the electrical reliability of the coil device can be reduced. Rise.

(7) In any one of the above (1) to (6), the large-diameter bridge-shaped conductor is preferably a series of metal members. With this configuration, the DCR of the large-diameter bridge-shaped conductor can be sufficiently reduced as compared with the case of a sintered metal body obtained by firing conductive paste or a thin film metal body obtained by etching a conductive thin film. And a low-loss coil device can be obtained. In addition, this configuration can reduce the number of connection points as compared with the case where, for example, a plurality of base material layers having interlayer conductors are stacked to form a connection portion in the height direction, so that the electrical reliability of the coil device can be reduced. Is further increased.

(8) In any one of the above (1) to (7), the small-diameter bridge-shaped conductor is preferably a series of metal members. With this configuration, the DCR of the small-diameter bridge-shaped conductor can be sufficiently reduced as compared with the case where the sintered metal body is formed by firing the conductive paste, or the thin film metal body is formed by etching the conductive thin film. A high and low loss coil device can be obtained. In addition, this configuration can reduce the number of connection points as compared with the case where, for example, a plurality of base material layers having interlayer conductors are stacked to form a connection portion in the height direction, so that the electrical reliability of the coil device can be reduced. Is further increased.

(9) In any one of the above (1) to (8), the large-diameter bridge-shaped conductor and the small-diameter bridge-shaped conductor have no gap along the first direction in plan view of the first main surface. Preferably they are arranged. With this configuration, the magnetic flux generated in the coil device hardly leaks from the gap between the large-diameter bridge-shaped conductor and the small-diameter bridge-shaped conductor that are adjacent to each other. Therefore, a coil device having a high inductance value can be configured.

(10) In any one of the above (1) to (9), the large-diameter bridge-shaped conductor and the small-diameter bridge-shaped conductor are from a direction parallel to the first main surface and a direction orthogonal to the first direction. As viewed, it is preferable that they are arranged without gaps along the first direction. With this configuration, the magnetic flux generated in the coil device hardly leaks from the gap between the large-diameter bridge-shaped conductor and the small-diameter bridge-shaped conductor that are adjacent to each other. Therefore, a coil device having a high inductance value can be configured.

(11) In any one of the above (1) to (10), the large-diameter loop and the small-diameter loop are alternately arranged in the first direction, and are alternately connected in order to form a helical coil. It is preferable to configure. With this configuration, it is possible to realize a coil device having a small occupied area (particularly, dimension in the first direction) relative to the number of turns. In addition, with this configuration, a conductor that does not contribute to inductance can be shortened by this configuration, so that the DCR of the coil device can be further reduced.

(12) In any one of the above (1) to (10), the number of the large diameter loops and the number of the small diameter loops are plural, and the plurality of large diameter loops are connected to each other to form a helical large diameter Preferably, the plurality of small-diameter loops are connected to each other to form a helical small-diameter coil, and the large-diameter coil is connected to the small-diameter coil. With this configuration, it is possible to easily configure a coil having a large number of turns for a small size.

(13) In the above (12), the extending direction from the first end to the second end of the large-diameter coil in the first direction is from the first end to the second end of the small-diameter coil in the first direction. The extending direction is opposite to the extending direction, and the second end of the large-diameter coil is preferably connected to the first end of the small-diameter coil. With this configuration, it is possible to realize a coil device having a small occupied area (particularly, dimension in the first direction) relative to the number of turns. Also, with this configuration, the conductor that does not contribute to the inductance can be shortened, so that the DCR of the coil device can be further reduced.

(14) The wireless IC device of the present invention
The coil device according to any one of (1) to (13),
RFIC mounted on the wiring board;
With
The coil device is connected to an antenna port of the RFIC.

  With this configuration, it is possible to realize a wireless IC device including a small coil device having a desired inductance value and excellent electrical characteristics, and particularly capable of reducing direct current resistance.

  According to the present invention, it is possible to realize a small coil device having a desired inductance value and excellent electrical characteristics, particularly capable of reducing a direct current resistance, and a wireless IC device including the coil device.

FIG. 1 is a perspective view of a wireless IC device 101 according to the first embodiment. 2A is a cross-sectional view of the wireless IC device 101, and FIG. 2B is a cross-sectional view of a different part of the wireless IC device 101. FIG. 3 is a perspective view showing each conductor of the coil device CD1 provided in the wireless IC device 101. FIG. FIG. 4 is a perspective view schematically showing each conductor portion of the coil device CD1. FIG. 5A is a perspective view schematically showing a conductor portion of a large-diameter loop included in the coil device CD1, and FIG. 5B schematically shows a conductor portion of a small-diameter loop included in the coil device CD1. FIG. FIG. 6 is a circuit diagram of the wireless IC device 101. FIG. 7A is a plan view of the coil device CD1, and FIG. 7B is a side view of the coil device CD1. FIG. 8 is a cross-sectional view illustrating the manufacturing process of the wireless IC device 101 in order. FIG. 9 is a cross-sectional view sequentially illustrating the manufacturing process of the wireless IC device 101. FIG. 10 is a perspective view schematically showing each conductor portion of the coil device CD2 according to the second embodiment. FIG. 11A is a perspective view schematically showing a conductor portion of a large-diameter loop provided in the coil device CD2, and FIG. 11B schematically shows a conductor portion of a small-diameter loop provided in the coil device CD2. FIG. 12A is a cross-sectional view of the wireless IC device 103 according to the third embodiment, and FIG. 12B is a cross-sectional view of a different part of the wireless IC device 103. FIG. 13 is a cross-sectional view illustrating the manufacturing process of the wireless IC device 103 in order. FIG. 14 is a cross-sectional view sequentially illustrating the manufacturing process of the wireless IC device 103. FIG. 15 is a cross-sectional view sequentially illustrating the manufacturing process of the wireless IC device 103A. FIG. 16 is a cross-sectional view sequentially illustrating the manufacturing process of the wireless IC device 103A. FIG. 17 is a cross-sectional view of the wireless IC device 104 according to the fourth embodiment. 18A is a cross-sectional view of the wireless IC device 105 according to the fifth embodiment, and FIG. 18B is a cross-sectional view of a different part of the wireless IC device 105.

  Hereinafter, several specific examples will be given with reference to the drawings to show a plurality of modes for carrying out the present invention. In each figure, the same reference numerals are assigned to the same portions. In consideration of ease of explanation or understanding of the main points, the embodiments are shown separately for convenience, but the components shown in different embodiments can be partially replaced or combined. In the second and subsequent embodiments, description of matters common to the first embodiment is omitted, and only different points will be described. In particular, the same operation effect by the same configuration will not be sequentially described for each embodiment.

  The coil devices according to some embodiments described below are coil antennas that can be used in, for example, the HF band, the LF band, the UHF band, the SHF band, and the like as magnetic flux radiating elements. The coil device can also be used as an inductor element. Therefore, unless otherwise specified, coil devices according to some embodiments described below are examples of both a coil antenna and an inductor element. In addition, wireless IC devices according to some embodiments described below include an RFIC and a coil device, and are, for example, RFID communication devices such as chip-shaped RFID tags provided in articles to be managed. The article to which the RFID tag is attached is, for example, portable information terminals such as toys and mobile phones, building materials such as scaffolding materials, and industrial materials such as gas cylinders.

<< First Embodiment >>
FIG. 1 is a perspective view of a wireless IC device 101 according to the first embodiment. 2A is a cross-sectional view of the wireless IC device 101, and FIG. 2B is a cross-sectional view of a different part of the wireless IC device 101. In FIG. 1, the large-diameter loop connection conductor and the small-diameter loop connection conductor are not shown in order to avoid complication of the drawing.

  The wireless IC device 101 includes a coil device CD1 and an RFIC3 (described in detail later).

  FIG. 3 is a perspective view showing each conductor of the coil device CD1 provided in the wireless IC device 101. FIG. FIG. 4 is a perspective view schematically showing each conductor portion of the coil device CD1. FIG. 5A is a perspective view schematically showing a conductor portion of a large-diameter loop included in the coil device CD1, and FIG. 5B schematically shows a conductor portion of a small-diameter loop included in the coil device CD1. FIG. In FIG. 3, the resin member 10, the large-diameter loop connection conductor, and the small-diameter loop connection conductor are not shown in order to avoid complication of the drawing. In FIG. 4, small-diameter loops are illustrated by broken lines in order to facilitate understanding of the structure of the coil device.

  The coil device CD1 includes a plurality of large-diameter loops BL1, BL2, BL3, BL4, a plurality of small-diameter loops SL1, SL2, SL3, SL4, a wiring board 1, and a resin member 10.

  The wiring board 1 is a flat plate having a first main surface PS1 and a second main surface PS2 and having a rectangular planar shape. The resin member 10 has a rectangular parallelepiped shape, and has a first surface VS1 and a second surface VS2. In the present embodiment, the resin member 10 includes a resin member 10A formed on the first main surface PS1 of the wiring board 1 and a resin member 10B. The resin member 10 is, for example, a thermosetting resin such as an epoxy resin. The wiring board 1 is, for example, an epoxy-based thermosetting printed wiring board, and is typically a double-sided through-hole board. However, the wiring board 1 is not limited to this, and may be a polyimide-based thermoplastic printed wiring board or a ceramic-based substrate. The wiring board 1 may be a single layer substrate or a multilayer substrate.

  The wiring board 1 is arranged such that the first main surface PS1 is embedded inside the resin member 10 and the second main surface PS2 is exposed from the resin member 10. In the present embodiment, the wiring board 1 is embedded in the resin member 10 so that the second main surface PS2 of the wiring board 1 and the second surface VS2 of the resin member 10 are on the same plane. Further, at least a part of the wiring board 1 is disposed inside the large-diameter loops BL1, BL2, BL3, BL4 when viewed from the Y-axis direction (corresponding to the “first direction” in the present invention). As shown in FIG. 2, the first main surface PS1 and the second main surface PS2 of the wiring board 1 are parallel to the X-axis direction and the Y-axis direction.

  The plurality of large-diameter loops BL1, BL2, BL3, BL4 have a winding axis AX in the Y-axis direction (corresponding to the “first direction” of the present invention). In the present embodiment, as shown in FIG. 1 and the like, at least a part of the plurality of large-diameter loops BL1, BL2, BL3, BL4 is embedded in the resin member 10.

  The plurality of large diameter loops BL1, BL2, BL3, BL4 include large diameter loop connection conductors Bj1, Bj2, Bj3, Bj4 and large diameter bridge-shaped conductors Bb1, Bb2, Bb3, Bb4. Specifically, the large-diameter loop BL1 includes a large-diameter loop connection conductor Bj1 and a large-diameter bridge-shaped conductor Bb1. The large-diameter loop BL2 includes a large-diameter loop connection conductor Bj2 and a large-diameter bridge conductor Bb2. The large-diameter loop BL3 includes a large-diameter loop connection conductor Bj3 and a large-diameter bridge conductor Bb3. The large-diameter loop BL4 includes a large-diameter loop connection conductor Bj4 and a large-diameter bridge conductor Bb4.

  The plurality of large-diameter loop connection conductors Bj1, Bj2, Bj3, Bj4 are conductors mainly formed in the inside of the wiring board 1 and the second main surface PS2, and the large-diameter bridge conductors Bb1, Bb2, Bb3, Bb4 Connected to the first end or the second end. In the present embodiment, the large-diameter bridge-shaped conductor includes a conductor pattern formed on the first main surface PS1 of the wiring board 1, an interlayer connection conductor and a conductor pattern formed inside the wiring board 1, and the first of the wiring board 1. It is comprised by the conductor pattern etc. which are formed over 2nd surface VS2 of the resin member 10 from 2 main surface PS2. For example, the large-diameter loop connection conductor Bj2 includes a conductor pattern 91 formed on the first main surface PS1 of the wiring board 1 and an interlayer connection conductor V1 formed inside the wiring board 1, as shown in FIG. And a conductive pattern 72 formed from the second main surface PS2 of the wiring board 1 to the second surface VS2 of the resin member 10.

  The large-diameter bridge conductors Bb1, Bb2, Bb3, and Bb4 are U-shaped (or inverted U-shaped) conductors that extend in the X-axis direction and the Y-axis direction, and are formed on the first main surface PS1 of the wiring board 1. It is perpendicular to it. The first end and the second end of the large-diameter bridge conductors Bb1, Bb2, Bb3, Bb4 are arranged outside the wiring board 1 when viewed from the Y-axis direction or the Z-axis direction, as shown in FIG. Yes. In the present embodiment, each of the large diameter bridge conductors Bb1, Bb2, Bb3, and Bb4 has substantially the same shape.

  Further, the large diameter bridge conductors Bb1, Bb2, Bb3, Bb4 include the first metal posts 11, 12, 13, 14, the second metal posts 21, 22, 23, 24 and the large diameter connection conductors 51, 52, 53, 54. Specifically, the large-diameter bridge-shaped conductor Bb1 is configured by sequentially connecting the first metal post 11, the large-diameter connection conductor 51, and the second metal post 21. The large-diameter bridge-shaped conductor Bb2 is configured by sequentially connecting the first metal post 12, the large-diameter connection conductor 52, and the second metal post 22. The large-diameter bridge conductor Bb3 is configured by sequentially connecting the first metal post 13, the large-diameter connection conductor 53, and the second metal post 23. The large-diameter bridge conductor Bb4 is configured by sequentially connecting the first metal post 14, the large-diameter connection conductor 54, and the second metal post 24.

  First metal posts 11, 12, 13, 14 and second metal posts 21, 22, 23, 24 are in the Z-axis direction (corresponding to “direction perpendicular to the first main surface” of the wiring board in the present invention). It is a columnar metal body that is stretched and arranged in the Y-axis direction. As shown in FIG. 3 and the like, the first metal posts 11, 12, 13, 14 and the second metal posts 21, 22, 23, 24 are outside the wiring board 1 when viewed from the Y-axis direction or the Z-axis direction. Has been placed. The first metal posts 11, 12, 13, 14 and the second metal posts 21, 22, 23, 24 are all, for example, cylindrical Cu pins, for example, cutting a Cu wire having a circular cross section in predetermined length units. It is obtained by doing. The cross-sectional shape is not necessarily circular, and may be a rectangle or a polygon.

  In the present embodiment, these first metal posts 11, 12, 13, and 14 correspond to the “first columnar metal portion” in the present invention, and the second metal posts 21, 22, 23, and 24 in the present invention “second column”. Corresponds to “columnar metal part”.

  The large-diameter connection conductors 51, 52, 53, and 54 are conductor patterns formed on the first surface VS1 of the resin member 10, and the first ends of the first metal posts 11, 12, 13, and 14 and the second metal posts. The first ends of 21, 22, 23, and 24 are connected. Specifically, the large-diameter connection conductor 51 connects the first end of the first metal post 11 and the first end of the second metal post 21. The large-diameter connection conductor 52 connects the first end of the first metal post 12 and the first end of the second metal post 22. The large-diameter connection conductor 53 connects the first end of the first metal post 13 and the first end of the second metal post 23. The large-diameter connection conductor 54 connects the first end of the first metal post 14 and the first end of the second metal post 24. The large-diameter connection conductors 51, 52, 53, 54 are metal films mainly composed of Cu or Ag, for example.

  The plurality of small-diameter loops SL1, SL2, SL3, and SL4 have a winding axis AX along the Y-axis direction. In the present embodiment, the winding axes of the large-diameter loops BL1, BL2, BL3, BL4 and the winding axes of the small-diameter loops SL1, SL2, SL3, SL4 coincide. In the present embodiment, at least a part of the plurality of small-diameter loops SL1, SL2, SL3, SL4 is embedded in the resin member 10.

  The plurality of small-diameter loops SL1, SL2, SL3, SL4 include small-diameter loop connection conductors Sj1, Sj2, Sj3 and small-diameter bridge-shaped conductors Sb1, Sb2, Sb3, Sb4. Specifically, the small-diameter loop SL1 includes a small-diameter bridge conductor Sb1 and a small-diameter loop connection conductor Sj1. The small diameter loop SL2 includes a small diameter bridge conductor Sb2 and a small diameter loop connection conductor Sj2. The small-diameter loop SL3 includes a small-diameter bridge-shaped conductor Sb3 and a small-diameter loop connection conductor Sj3. The small-diameter loop SL4 includes a small-diameter bridge-shaped conductor Sb4.

  The plurality of small-diameter loop connection conductors Sj1, Sj2, Sj3 are conductors mainly formed on the inside of the wiring board 1 and the first main surface PS1, and the first end or the second end of the small-diameter bridge-shaped conductors Sb1, Sb2, Sb3. Connected to the end. In the present embodiment, the small-diameter loop connection conductor is a conductor pattern formed on the first main surface PS1 of the wiring board 1, an interlayer connection conductor or conductor pattern formed inside the wiring board 1, and the second of the wiring board 1. The conductor pattern is formed from the main surface PS2 to the second surface VS2 of the resin member 10. For example, the small-diameter loop connection conductor Sj1 includes a conductor pattern 92 formed on the first main surface PS1 of the wiring board 1, an interlayer connection conductor V2 formed inside the wiring board 1, as shown in FIG. And a conductor pattern 71 formed from the second main surface PS2 of the wiring board 1 to the second surface VS2 of the resin member 10.

  The small-diameter bridge-shaped conductors Sb1, Sb2, Sb3, and Sb4 are U-shaped (or inverted U-shaped) conductors that extend in the X-axis direction and the Y-axis direction, and are connected to the first main surface PS1 of the wiring board 1. And vertical. The small diameter bridge conductors Sb1, Sb2, Sb3, and Sb4 are mounted on the first main surface PS1 of the wiring board 1. In the present embodiment, each of the small-diameter bridge conductors Sb1, Sb2, Sb3, Sb4 has substantially the same shape.

  The outer diameter dimensions of the small-diameter bridge conductors Sb1, Sb2, Sb3, Sb4 are smaller than the outer diameter dimensions of the large-diameter bridge conductors Bb1, Bb2, Bb3, Bb4 when viewed from the Y-axis direction. Further, the inner diameter dimensions of the small-diameter bridge conductors Sb1, Sb2, Sb3, Sb4 are smaller than the inner diameter dimensions of the large-diameter bridge conductors Bb1, Bb2, Bb3, Bb4 when viewed from the Y-axis direction. Therefore, the small-diameter bridge conductors Sb1, Sb2, Sb3, and Sb4 are disposed inside the outer diameter of the large-diameter bridge conductors Bb1, Bb2, Bb3, and Bb4 when viewed from the Y-axis direction. In the present embodiment, the small-diameter bridge conductors Sb1, Sb2, Sb3, and Sb4 are arranged inside the inner diameters of the large-diameter bridge conductors Bb1, Bb2, Bb3, and Bb4 when viewed from the Y-axis direction.

  The small-diameter bridge conductors Sb1, Sb2, Sb3, and Sb4 include the third metal posts 31, 32, 33, and 34, the fourth metal posts 41, 42, 43, and 44, and the small-diameter connection conductors 61, 62, 63, and 64, respectively. Have. Specifically, the small-diameter bridge-shaped conductor Sb1 is configured by sequentially connecting the third metal post 31, the small-diameter connection conductor 61, and the fourth metal post 41. The small-diameter bridge-shaped conductor Sb2 is configured by sequentially connecting the third metal post 32, the small-diameter connection conductor 62, and the fourth metal post 42. The small-diameter bridge conductor Sb3 is configured by sequentially connecting the third metal post 33, the small-diameter connection conductor 63, and the fourth metal post 43. The small-diameter bridge conductor Sb4 is configured by sequentially connecting the third metal post 34, the small-diameter connection conductor 64, and the fourth metal post 44.

  The third metal posts 31, 32, 33, and 34 and the fourth metal posts 41, 42, 43, and 44 are columnar metal bodies that extend in the Z-axis direction and are arranged in the Y-axis direction. As shown in FIG. 3 and the like, the second ends of the third metal posts 31, 32, 33 and 34 and the second ends of the fourth metal posts 41, 42, 43 and 44 are the first main surface PS 1 of the wiring board 1. Are implemented respectively. The third metal posts 31, 32, 33, 34 and the fourth metal posts 41, 42, 43, 44 are all, for example, cylindrical Cu pins, for example, cutting a Cu wire having a circular cross section in a predetermined length unit. It is obtained by doing. The cross-sectional shape is not necessarily circular, and may be a rectangle or a polygon.

  In the present embodiment, these third metal posts 31, 32, 33, and 34 correspond to the “third columnar metal portion” in the present invention, and the fourth metal posts 41, 42, 43, and 44 in the present invention are “fourth”. Corresponds to “columnar metal part”.

  As shown in FIGS. 2A and 2B, the first metal post and the second metal post that constitute a part of the large-diameter loop are the third metal that constitutes a part of the small-diameter loop. The conductor diameter is thicker than the post and the fourth metal post. In other words, the cross-sectional areas of the first metal post and the second metal post are larger than the cross-sectional areas of the third metal post and the fourth metal post.

  The small-diameter connection conductors 61, 62, 63, 64 are conductor patterns formed inside the resin member 10, and the first ends of the third metal posts 31, 32, 33, 34 and the fourth metal posts 41, 42, The first ends of 43 and 44 are connected. Specifically, the small-diameter connection conductor 61 connects the first end of the third metal post 31 and the first end of the fourth metal post 41. The small-diameter connection conductor 62 connects the first end of the third metal post 32 and the first end of the fourth metal post 42. The small-diameter connection conductor 63 connects the first end of the third metal post 33 and the first end of the fourth metal post 43. The small diameter connecting conductor 64 connects the first end of the third metal post 34 and the first end of the fourth metal post 44. The small-diameter connection conductors 61, 62, 63, 64 are metal films mainly composed of Cu or Ag, for example.

  In the coil device CD1 according to this embodiment, the plurality of large-diameter loops BL1, BL2, BL3, BL4 and the plurality of small-diameter loops SL1, SL2, SL3, SL4 are alternately and sequentially arranged in the Y-axis direction, and , Are alternately connected in sequence and conducted. Therefore, the coil device CD1 constitutes a helical coil as shown in FIG.

  1 and 2A, the RFIC 3 is embedded in the resin member 10 and mounted on the first main surface PS1 of the wiring board 1. The antenna port of the RFIC 3 is connected to mounting electrodes 81 and 82 formed on the first main surface PS1 of the wiring board 1, respectively. These mounting electrodes 81 and 82 are electrically connected to the first end E1 and the second end E2 of the coil device CD1 shown in FIG. The RFIC 3 is, for example, a packaged RFIC chip (bare chip). The RFIC 3 may be a bare chip-shaped RFIC chip. The RFIC chip and the mounting electrodes 81 and 82 (land pattern) may be connected by a wire.

  FIG. 6 is a circuit diagram of the wireless IC device 101.

  The RFIC 3 includes, for example, an HF band high-frequency wireless IC chip for an HF band RFID system. The coil device CD1 is connected to the RFIC 3, and an LC resonance circuit is constituted by the coil device CD1 and the capacitance component of the RFIC 3 itself. Its resonant frequency is substantially equal to the communication frequency of the RFID system. The communication frequency band is, for example, the 13.56 MHz band.

  The “RFIC” may be an RFIC chip itself or an RFIC package in which an RFIC chip is mounted on a substrate provided with a matching circuit and the like. An “RFID tag” has an RFIC element and a coil antenna connected to the RFIC element, and uses non-contact information to read and write data in a built-in memory using radio waves (electromagnetic waves) or magnetic fields. Defined as medium. That is, the wireless IC device of this embodiment is configured as an RFIC tag.

  Next, the arrangement of the large-diameter bridge-like conductor and the small-diameter bridge-like conductor in the present embodiment will be described with reference to the drawings. FIG. 7A is a plan view of the coil device CD1, and FIG. 7B is a side view of the coil device CD1. 7A and 7B, the resin member is not shown in order to facilitate understanding of the structure of the coil device CD1.

  In the present embodiment, the plurality of large-diameter connection conductors 51, 52, 53, and 54 and the plurality of small-diameter connection conductors 61, 62, 63, and 64 are alternately arranged in the Y-axis direction. As shown in FIG. 7A, in the coil device CD1, the large-diameter bridge-shaped conductors and the small-diameter bridge-shaped conductors are arranged without gaps along the Y-axis direction when viewed from the Z-axis direction.

  In the present embodiment, the plurality of first metal posts 11, 12, 13, and 14 and the plurality of third metal posts 31, 32, 33, and 34 are alternately arranged in the Y-axis direction. The plurality of second metal posts 21, 22, 23, and 24 and the plurality of fourth metal posts 41, 42, 43, and 44 are alternately arranged in the Y-axis direction. As shown in FIG. 7B, in the coil device CD1, the large-diameter bridge-shaped conductor and the small-diameter bridge-shaped conductor are arranged in the X-axis direction (in the direction parallel to the first main surface and the first direction in the present invention). (Corresponding to the “perpendicular direction”), they are arranged without gaps along the Y-axis direction.

  The wireless IC device 101 according to the present embodiment has the following effects.

(A) In the present embodiment, the first end and the second end (first metal posts 11, 12, 13, and 14 and second metal posts 21, 22, 23, and 24) of the large-diameter bridge-shaped conductor are connected to the wiring board 1. Therefore, it is not necessary to form lands on the wiring board 1 for mounting the first end and the second end of the large-diameter bridge-shaped conductor. Therefore, the large-diameter bridge conductor and the small-diameter bridge conductor can be arranged at a narrow pitch in the Y-axis direction. Therefore, with this configuration, the area occupied by the coil (dimension in the Y-axis direction) can be reduced for the number of turns.

(B) In the present embodiment, at least a part of the large-diameter bridge conductors Bb1, Bb2, Bb3, Bb4 and the small-diameter bridge conductors Sb1, Sb2, Sb3, Sb4 constituting the coil device CD1 are metal posts (metal members). It consists of Therefore, the DCR of the large-diameter bridge-like conductor and the small-diameter bridge-like conductor can be reduced as compared with the case where the sintered metal body is formed by firing the conductive paste, or the thin film metal body is formed by etching the conductive thin film. And a low-loss coil device can be obtained. In addition, since the resistance of the entire coil device can be reduced, a highly sensitive wireless IC device or a small wireless IC device for high sensitivity can be obtained.

(C) In this embodiment, since the metal post is used for a part of the large-diameter bridge-shaped conductor and a part of the small-diameter bridge-shaped conductor, it is not necessary to form a coil on the multilayer substrate, and a complicated wiring is provided. There is no need to run around. Therefore, it is possible to easily realize a coil structure excellent in design freedom of the coil opening size. Furthermore, since a portion having a relatively large height can be formed by a metal post, for example, compared with a case where a plurality of base material layers having interlayer conductors are stacked to form a connection portion in the height direction. And the electrical reliability of the coil device is increased.

(D) In the present embodiment, the large-diameter connection conductors 51, 52, 53, and 54 and the small-diameter connection conductors 61, 62, 63, and 64 used for a part of the large-diameter bridge-shaped conductor and a part of the small-diameter bridge-shaped conductor. Are not wires or the like, but are both conductor patterns formed inside the resin member 10 or on the first surface VS1. Therefore, since the possibility of contact (short between lines) between adjacent large-diameter connection conductors or between adjacent small-diameter connection conductors is low, the gap between large-diameter connection conductors arranged in the Y-axis direction can be easily reduced, The gap between the small diameter connecting conductors arranged in the Y-axis direction can be easily reduced. Also, by selecting the gap between the large-diameter connection conductors and the gap between the small-diameter connection conductors, the desired number of turns and the desired inductance value can be obtained even if the occupation area (dimension in the Y-axis direction) is the same. It becomes easy to obtain the helical coil which has.

(E) In the present embodiment, the first main surface PS1 of the wiring board 1 on which the RFIC 3 is mounted is a direction (Y-axis direction) parallel to the winding axis AX of the large-diameter loop and the small-diameter loop. The mounting electrodes 81 and 82 (land pattern) are unlikely to hinder the formation of the magnetic field of the coil device CD1. Further, the adverse effect (malfunction, unstable operation, etc.) on the RFIC 3 due to the magnetic field of the coil device CD1 is small. Furthermore, the adverse effect on the coil device due to noise generated from the digital circuit portion of the RFIC 3 (decrease in reception sensitivity, wraparound of transmission signals to the reception circuit, etc.) is small.

(F) As for the wireless IC device, the RFIC 3 is arranged inside the coil device. Therefore, the protection function of the RFIC 3 is enhanced, and an increase in size due to mounting the RFIC 3 outside the coil device can be avoided.

(G) The wireless IC device 101 includes a surface mount component such as RFIC3, a part of a large-diameter loop (first metal post, second metal post), and a part of a small-diameter loop (third metal post, fourth metal post). Is protected by the resin member 10, the entire wireless IC device is robust. In particular, when the wireless IC device is embedded in a resin molded article, the solder connection portion of the surface mount chip component is protected against a high temperature resin (for example, a high temperature resin of 300 ° C. or higher) that flows during injection molding. That is, the RFIC 3 includes the large-diameter bridge conductors Bb1, Bb2, Bb3, Bb4, the small-diameter bridge conductors Sb1, Sb2, Sb3, Sb4, the large-diameter loop connection conductors Bj1, Bj2, Bj3, Bj4 and the small-diameter that constitute the coil device CD1. It is disposed in an area surrounded by the loop connection conductors Sj1, Sj2, Sj3 and the like, and is surrounded by the resin member 10 and the wiring board 1. With this configuration, it is difficult to apply a large thermal load to the connection portion between the RFIC 3 and the mounting electrodes 81 and 82 and the RFIC 3. Therefore, even when the wireless IC device 101 is embedded in a resin molded article (toy, container, etc.), the operational reliability of the RFIC 3 can be ensured, and the reliability of the connection portion between the RFIC 3 and the mounting electrode can be increased. . That is, a highly heat-resistant wireless IC device that can be built into a resin molded body, that is, can withstand high temperatures during injection molding can be realized. In addition, even when the solder joint is once melted at a high temperature, the resin member 10 and the wiring board 1 are bonded to each other by joining the resins, and the surface-mounted component and the small-diameter bridge-shaped conductor are not detached or deformed. After cooling, the joined state of the solder joint returns to normal. Therefore, the inductance value of the coil antenna can be maintained.

(H) Since the RFIC 3 is not exposed to the outside of the wireless IC device 101, the protection function of the RFIC 3 is enhanced, and an increase in size caused by mounting the RFIC 3 outside can be avoided. Further, the reliability of the connection portion of the RFIC 3 with respect to the wiring board 1 is increased. As a result, it is possible to realize a highly heat-resistant wireless IC device that can be incorporated in a resin molded product such as plastic, that is, can withstand high temperatures during injection molding.

(I) In the present embodiment, as shown in FIG. 2A, the main part of the large-diameter loop connection conductor constituting the large-diameter loop is formed on the second main surface PS2 side of the wiring board 1, The substantial opening diameter of the coil device CD1 is large. Therefore, a coil antenna having a size substantially equal to the size of the chip-shaped wireless IC device 101 can be configured, and a large communication distance can be ensured despite being a small chip-shaped component, Further, communication can be performed with a relatively wide positional relationship with the antenna of the communication partner.

(J) In the present embodiment, since the large-diameter connection conductors 51, 52, 53, 54 are formed on the surface of the resin member 10 by patterning, the first ends of the first metal posts 11, 12, 13, 14 Connection between the first ends of the second metal posts 21, 22, 23, 24 is facilitated.

(K) As described in detail later, among the patterns constituting the large-diameter loop and the small-diameter loop, the large-diameter connection conductors 51, 52, 53, 54 and the small-diameter connection conductors 61, 62, 63, extending in the X-axis direction. No. 64 can be made thicker by forming a plating film such as Cu. Therefore, the DCR of the coil device can be further reduced.

(L) In this embodiment, a plurality of large-diameter loops BL1, BL2, BL3, BL4 and a plurality of small-diameter loops SL1, SL2, SL3, SL4 are alternately arranged in the Y-axis direction, and are alternately connected in sequence. This constitutes a helical coil. With this configuration, it is possible to easily configure a coil device having a large number of turns for a small size. In addition, a coil device having a small occupied area (particularly, a dimension in the Y-axis direction) relative to the number of turns can be realized. Also, with this configuration, the conductor that does not contribute to the inductance can be shortened, so that the DCR of the coil device can be further reduced.

(M) The wireless IC device 101 has a structure in which the wiring board 1 is embedded in the resin member 10 so that the second main surface PS2 of the wiring board 1 and the second surface VS2 of the resin member 10 are on the same plane. A part of the radial loop connection conductor is routed across the second main surface PS2 and the second surface VS2. Therefore, it is easy to connect the large diameter bridge conductor and the large diameter loop connection conductor.

(N) In the present embodiment, the plurality of large-diameter loop connection conductors Bj1, Bj2, Bj3, Bj4 are conductors mainly formed in the inside of the wiring board 1 and the second main surface PS2, and a plurality of small-diameter loop connections The conductors Sj1, Sj2, and Sj3 are conductors formed mainly on the inside of the wiring board 1 and the first main surface PS1. In this configuration, the large-diameter loop connection conductors Bj1, Bj2, Bj3, Bj4 and the small-diameter loop connection conductors Sj1, Sj2, Sj3 can be easily configured by using the conductor formed on the wiring board 1.

(O) In this embodiment, the large-diameter bridge conductors Bb1, Bb2, Bb3, and Bb4 and the small-diameter bridge conductors Sb1, Sb2, Sb3, and Sb4 are arranged without gaps along the Y-axis direction as viewed from the Z-axis direction. Has been. With this configuration, the magnetic flux generated in the coil device hardly leaks from the gap between the large-diameter bridge-shaped conductor and the small-diameter bridge-shaped conductor that are adjacent to each other. Therefore, a coil device having a high inductance value can be configured. Further, when the coil device is used as a coil antenna, magnetic field coupling can be performed with a relatively wide positional relationship with respect to the coil antenna on the communication partner side. Since the magnetic flux is more difficult to leak from the gap between the large-diameter bridge-shaped conductor and the small-diameter bridge-shaped conductor adjacent to each other, the edge of the large-diameter bridge-shaped conductor in the Y-axis direction and the small-diameter bridge are viewed from the Z-axis direction. It is preferable that the edge portion in the Y-axis direction of the shaped conductor partially overlaps (see FIG. 7A).

(P) In the present embodiment, the large-diameter bridge conductors Bb1, Bb2, Bb3, and Bb4 and the small-diameter bridge conductors Sb1, Sb2, Sb3, and Sb4 are gaps along the Y-axis direction when viewed from the X-axis direction. There is no array. As described above, with this configuration, a coil device having a high inductance value can be configured. Further, when the coil device is used as a coil antenna, magnetic field coupling can be performed with a relatively wide positional relationship with respect to the coil antenna on the communication partner side. In order to make it more difficult for magnetic flux to leak from the gap between the large-diameter bridge-shaped conductor and the small-diameter bridge-shaped conductor that are adjacent to each other, the edge portion in the Y-axis direction of the large-diameter bridge-shaped conductor It is preferable that the edge portion in the Y-axis direction of the shaped conductor partially overlaps (see FIG. 7B).

  In addition, in this embodiment, although the structural example of coil device CD1 provided with the resin member 10 was shown, it is not limited to this structure. The coil device may not be provided with the resin member 10. In that case, the large-diameter connection conductors 51, 52, 53, and 54 and the small-diameter connection conductors 61, 62, 63, and 64 may be metal members that are not supported by any support such as a hoop material or a metal post.

  In the present embodiment, the large-diameter bridge conductors Bb1, Bb2, Bb3, Bb4 and the small-diameter bridge conductors Sb1, Sb2, Sb3, Sb4 are perpendicular to the first main surface PS1 of the wiring board 1. Although shown, it is not limited to this. The large-diameter bridge conductors Bb1, Bb2, Bb3, Bb4 and the small-diameter bridge conductors Sb1, Sb2, Sb3, Sb4 need only be non-parallel to the first main surface PS1 of the wiring board 1. It suffices if the angle formed with one principal surface PS1 exceeds 0 ° and is less than 90.

  In the present embodiment, an example of a wireless IC device in which the RFIC 3 is mounted on the first main surface PS1 of the wiring board 1 is shown, but the present invention is not limited to this configuration. In addition to the RFIC 3, a surface mount component such as a chip capacitor may be mounted on the first main surface PS 1 of the wiring board 1.

  In the present embodiment, the configuration example including four large-diameter loops and four small-diameter loops is shown, but the present invention is not limited to this. The number of large diameter loops and the number of small diameter loops need not be the same. The number of large-diameter loops and the number of small-diameter loops may be 1, and one large-diameter loop and one small-diameter loop may be connected to form a two-turn helical coil. Further, a spiral coil may be formed by connecting one small diameter loop to one large diameter loop.

  In the present embodiment, each of the plurality of large-diameter bridge conductors Bb1, Bb2, Bb3, and Bb4 has substantially the same shape, and each of the plurality of small-diameter bridge conductors Sb1, Sb2, Sb3, and Sb4 has approximately the same shape. Although a certain configuration example is shown, the present invention is not limited to this. In the range where the functions and effects of the present invention are exhibited, the plurality of large-diameter bridge conductors may have different shapes, and the plurality of small-diameter bridge conductors may have different shapes. In view of ease of manufacturing the coil device CD1, etc., it is preferable that each of the plurality of large-diameter bridge conductors has substantially the same shape, and each of the plurality of small-diameter bridge conductors has substantially the same shape. preferable.

  The wireless IC device 101 according to the present embodiment is manufactured by, for example, the following process. 8 and 9 are cross-sectional views sequentially showing the manufacturing process of the wireless IC device 101. FIG.

  First, as shown in (1) in FIG. 8, the wiring board 1 is prepared. Specifically, conductor patterns 91 and 92 and mounting electrodes 81 and 82 (land patterns) for mounting RFIC are formed on the first main surface PS1 of the wiring board 1. Further, in the thickness direction of the wiring board 1, an interlayer connection conductor V <b> 1 connected to the conductor pattern 91 and formed inside the wiring board 1 is formed.

  Thereafter, the conductive bonding material 4 such as solder paste is formed on the mounting electrodes 81 and 82 for mounting the RFIC, the conductor patterns 91 and 92 for mounting the metal posts, and the like. At this time, no conductor pattern is formed on the second main surface PS2 side of the wiring board 1.

  The wiring board 1 is, for example, a glass epoxy board or an epoxy thermosetting printed wiring board, but may be a polyimide board or other thermoplastic board or ceramic board formed with a thick film pattern. The wiring board 1 may be a single layer substrate or a multilayer substrate. The mounting electrodes 81 and 82 and the conductor patterns 91 and 92 linear conductor patterns are formed by patterning a metal foil having a small specific resistance such as Cu or Ag, but the plating film is formed on the first main surface PS1 of the wiring board 1. Or a pattern obtained by patterning a conductive paste. For example, the cross-sectional dimensions of the mounting electrodes 81 and 82 and the conductor patterns 91 and 92 are 18 μm × 100 μm. After performing these patterning, it is preferable to perform plating of Cu or the like to increase the total film thickness to 40 to 50 μm. The interlayer connection conductor V <b> 1 is a through hole in which a plating film is provided on the inner wall of a through hole that penetrates the wiring board 1, for example.

  Next, as shown in (2) in FIG. 8, components such as the RFIC 3, the third metal post 32, and the fourth metal post 42 are mounted on the wiring board 1 through conductive bonding materials such as solder. . Specifically, after mounting each component on the first main surface PS1 of the wiring board 1 with a mounter, these components are soldered by a reflow process. Through this process, the RFIC 3, the third metal post 32, the fourth metal post 42, and the like are electrically connected to the wiring board 1 and structurally joined.

  RFIC3 is a packaged RFIC chip for an RFID tag. Each of the third metal post and the fourth metal post is a cylindrical post made of Cu. The third metal post and the fourth metal post are not limited to those having Cu as a main component, but those having Cu as a main component are preferable in terms of conductivity and workability.

  Next, as shown in (3) in FIG. 8, the same height as the third metal post 32 and the fourth metal post 42 (at least the height at which the RFIC 3 and the first main surface PS1 of the wiring board 1 are embedded). The resin member 10B is formed (covered with resin). Specifically, an epoxy resin or the like is applied to a predetermined height (more than the height of the third metal post 32 and the fourth metal post 42), and then the surface of the resin member 10B is polished planarly. Then, the heads of the first metal post 32 and the second metal post 42 are exposed. An epoxy resin or the like is applied to a predetermined height (not more than the height of the metal post), and then the resin member 10B is polished (or cut) together with the metal post in a planar manner on the surface of the resin member 10B. The head of the metal post may be exposed.

  The resin member 10B may be provided by applying a liquid resin, or may be provided by stacking semi-cured sheet-like resins.

  Thereafter, the small-diameter connection conductor 62 and the like are formed on the surface of the resin member 10B. Specifically, a conductor film such as a Cu film is formed by plating or the like on the third surface VS3 of the resin member 10B where the heads of the third metal post 32 and the fourth metal post 42 are exposed, and this is formed into a photoresist. Patterning is performed by film formation and etching. Further, the small-diameter connection conductor 62 and the like may be formed by screen printing a conductive paste. As a result, the small diameter connecting conductor is connected between the second end of the third metal post and the second end of the fourth metal post.

  After that, it is preferable to form a plating film on the small-diameter connection conductor 62 or the like by plating with Cu or the like. In the case of a Cu plating film, an Au plating film may be further formed on the surface of a plating film such as Cu. By these things, the film thickness of the small diameter connecting conductor 62 etc. becomes thick, those DCR becomes small, and conductor loss can be reduced. Thereby, the DCR of the small-diameter connection conductor 62 and the like can be reduced to the same extent as the DCR of the third metal post 32 and the fourth metal post 42 and the like. That is, since the element body at this stage has the small-diameter connection conductor exposed on the outer surface, the thickness of the small-diameter connection conductor can be selectively increased by immersing the element body 300A in the plating solution. .

  Thereafter, as required, a protective resin film (such as a solder resist film) for preventing oxidation is formed on the surface of the resin member 10B where the small-diameter connection conductor 62 and the like are formed.

  In addition, said process is processed with a mother substrate state. After the above steps, the mother substrate is separated into individual element bodies 300A (individual pieces).

  Next, as shown in (4) in FIG. 8, the element body 300A is mounted on the support base 7 having an adhesive layer or the like. In the element body 300A, the second main surface PS2 side of the wiring board 1 is mounted on the support base 7 via an adhesive layer. Thereby, the wiring board 1 is mounted in a state of being firmly fixed to the support base 7.

  Thereafter, as shown in (5) in FIG. 9, the first end side of the first metal post 12 and the like and the first end side of the second metal post 22 and the like are set to the support base 7 side in a standing state. Implement. Thus, the first metal post 12 and the second metal post 22 are mounted in a state of being firmly fixed to the support base 7.

  The adhesive layer included in the support base 7 is, for example, an adhesive resin. Each of the first metal post and the second metal post is a cylindrical post made of Cu. The first metal post and the second metal post are not limited to those having Cu as a main component, but those having Cu as a main component are preferable in terms of conductivity and workability.

  Next, as shown in (6) and (7) in FIG. 9, the resin member 10 </ b> A to the same height as the first metal post 12, the second metal post 22, etc. (at least the height at which the entire element body 300 </ b> A is embedded). Is formed (coated with resin). Specifically, the resin member 10A coated with an epoxy-based resin or the like at a predetermined height (the height of the metal post) is planarized to the polishing line PL1 shown in FIG. By polishing (or cutting), heads such as the first metal post 12 and the second metal post 22 are exposed from the surface of the resin member 10A. The resin member 10 </ b> A formed on the support base 7 may be equal to or less than the height of the first metal post 12, the second metal post 22, and the like.

  Further, as shown in (6) and (7) in FIG. 9, the support base 7 is removed from the resin member 10A, the base body 300A, and the like, and the heads and interlayer connection of the first metal post 12 and the second metal post 22 and the like. The conductor V1 and the like are exposed from the surface of the resin member 10A. Specifically, the resin member 10A is polished (or cut) in a planar manner to the polishing line PL2 indicated by (6) in FIG. 9 together with the support base 7, the wiring board 1, and the metal post. Heads such as the first metal post 12 and the second metal post 22 and the interlayer connection conductor V1 are exposed from the second main surface PS2 of the wiring board 1 and the second surface VS2 of the resin member 10A.

  Next, as shown at (8) in FIG. 9, the large-diameter connection conductor 52 and the like are formed on the first surface VS1 of the resin member 10, and the second surface VS2 of the resin member 10 and the second main main portion of the wiring board 1 are formed. Conductive patterns 71 and 72 are formed on the surface PS2. Thereafter, a plating film is formed on the large-diameter connection conductor 52 and the conductor patterns 71 and 72 by plating with Cu or the like.

  Then, if necessary, a protective resin film (for prevention of oxidation) is formed on the formation surfaces of the conductor patterns 71 and 72 formed on the outer surface (second main surface PS2) of the wiring board 1 and the second surface VS2 of the resin member 10. A solder resist film).

  In addition, said process is processed with a mother substrate state. Finally, the mother board is separated into individual wireless IC device 101 units (pieces).

  According to the above manufacturing method, it is possible to easily manufacture a wireless IC device including a small coil device having a desired inductance value and excellent electrical characteristics, and particularly capable of reducing direct current resistance.

<< Second Embodiment >>
In the second embodiment, an example in which the connection relationship between the plurality of large-diameter loops and the plurality of small-diameter loops is different from that of the coil device CD1 according to the first embodiment is shown. Other configurations are substantially the same as those of the coil device CD1.

  FIG. 10 is a perspective view schematically showing each conductor portion of the coil device CD2 according to the second embodiment. FIG. 11A is a perspective view schematically showing a conductor portion of a large-diameter loop provided in the coil device CD2, and FIG. 11B schematically shows a conductor portion of a small-diameter loop provided in the coil device CD2. FIG. In FIG. 10, in order to make the structure of the coil device easier to understand, the small-diameter loop is shown by a broken line.

  The coil device CD2 includes a plurality of large diameter loops BL1, BL2, BL3, BL4 and a plurality of small diameter loops SL1, SL2, SL3, SL4.

  The plurality of large diameter loops BL1, BL2, BL3, BL4 are connected to each other to form a helical large diameter coil BC of about 4 turns, and the plurality of small diameter loops SL1, SL2, SL3, SL4 are connected to each other. A helical small-diameter SC having about 4 turns is formed.

  As shown in FIG. 11A, the extending direction (+ Y direction) from the first end Be1 to the second end Be2 of the large-diameter coil BC in the Y-axis direction is the first end Se1 of the small-diameter coil SC in the Y-axis direction. The direction opposite from the extending direction (-Y direction) toward the second end Se <b> 2 is the opposite direction. The second end Be2 of the large diameter coil BC is connected to the first end Se1 of the small diameter coil SC.

  As shown in FIG. 10, at least part of the large-diameter loop formation region BFE in the Y-axis direction overlaps the small-diameter loop formation region SFE in the Y-axis direction.

  With this configuration, it is possible to achieve the same operations and effects as those of the coil device CD1 according to the first embodiment.

  In the present embodiment, the coil device CD2 including the large-diameter coil BC of about 4 turns and the small-diameter coil SC of about 4 turns is shown, but the present invention is not limited to this. The number of turns of the large-diameter coil BC and the number of turns of the small-diameter coil can be appropriately changed as long as they are larger than one. In the present embodiment, the configuration in which one large-diameter coil BC and one small-diameter coil SC are connected is shown, but the present invention is not limited to this. A plurality of large-diameter coils and a plurality of small-diameter coils may be alternately and sequentially connected. Moreover, the number of large diameter coils and the number of small diameter coils do not need to be the same number. The plurality of large-diameter coils may have different numbers of turns, and the plurality of small-diameter coils may have different numbers of turns.

  Moreover, in 1st Embodiment, although coil device CD1 of the structure provided with a large diameter loop and a small diameter loop was shown, in this embodiment, coil device CD2 of the structure provided with a large diameter coil and a small diameter coil was shown, It is not limited to this. The coil device in this invention should just be the structure which combines two or more of a large diameter loop, a small diameter loop, a large diameter coil, and a small diameter coil. In addition, when combining two or more of a large diameter loop, a small diameter loop, a large diameter coil, and a small diameter coil, the order in which they are connected can be appropriately changed.

<< Third Embodiment >>
In the third embodiment, an example in which the structures of the large-diameter bridge-like conductor and the small-diameter bridge-like conductor are different from those of the wireless IC device 101 according to the first embodiment is shown. Other configurations are substantially the same as those of the wireless IC device 101.

  12A is a cross-sectional view of the wireless IC device 103 according to the third embodiment, and FIG. 12B is a cross-sectional view of a different part of the wireless IC device 103.

  The plurality of large-diameter bridge-shaped conductors according to the present embodiment (in FIG. 12A and FIG. 12B, the large-diameter bridge-shaped conductor Bb2 appears) are each a series of metal members, and the X-axis direction And a U-shaped (or inverted U-shaped) metal body extending in the Z-axis direction and arranged in the Y-axis direction. In the present embodiment, the entire large-diameter bridge-like conductor is embedded in the resin member 10. The large-diameter bridge-shaped conductor according to the present embodiment can be obtained by, for example, bending a Cu wire having a circular cross section into an inverted U shape and then cutting it. The cross-sectional shape is not necessarily circular, and may be a rectangle or a polygon.

  In the present embodiment, the portion extending in the Z-axis direction in the large-diameter bridge-shaped conductor corresponds to the “first columnar metal portion” and the “second columnar metal portion” in the present invention.

  A plurality of small-diameter bridge-shaped conductors according to the present embodiment (the small-diameter bridge-shaped conductors Sb1 and Sb2 appear in FIGS. 12A and 12B) are a series of metal members, respectively, in the X-axis direction. And a U-shaped (or inverted U-shaped) metal body extending in the Z-axis direction and arranged in the Y-axis direction. In the present embodiment, the entire small-diameter bridge-like conductor is embedded in the resin member 10. Moreover, in this embodiment, as shown to FIG. 12 (A) and FIG. 12 (B), a small diameter bridge-like conductor is arrange | positioned inside a large diameter bridge-like conductor seeing from a Y-axis direction. The small-diameter bridge-shaped conductor according to the present embodiment can be obtained by, for example, bending a Cu wire having a circular cross section into an inverted U shape and then cutting it. The cross-sectional shape is not necessarily circular, and may be a rectangle or a polygon.

  In the present embodiment, the portion extending in the Z-axis direction of the small-diameter bridge-shaped conductor corresponds to the “third columnar metal portion” and the “fourth columnar metal portion” in the present invention.

  The wireless IC device 103 according to the present embodiment has the following effects in addition to the effects described in the first embodiment.

(Q) In the present embodiment, the plurality of large-diameter bridge-shaped conductors and the plurality of small-diameter bridge-shaped conductors are formed of a series of metal members. With this configuration, the DCR of the large-diameter bridge-like conductor and the small-diameter bridge-like conductor can be sufficiently reduced as compared with the case of a sintered metal body obtained by firing conductive paste, a thin film metal body obtained by etching a conductive thin film, or the like. Therefore, a coil device with a higher Q value and a lower loss can be obtained.

(R) Further, in this embodiment, since a series of metal members are used for the large-diameter bridge-shaped conductor and the small-diameter bridge-shaped conductor, it is not necessary to form a coil on the multilayer substrate, and complicated wiring is routed. There is no need. Therefore, it is possible to easily realize a coil structure excellent in design freedom of the coil opening size. In addition, this configuration can reduce the number of connection points as compared with the case where a plurality of base material layers having interlayer conductors are stacked to form a connection portion in the height direction, so that the electrical reliability of the coil device is improved. Further increase.

  The wireless IC device 103 according to the present embodiment is manufactured by, for example, the following process. 13 and 14 are cross-sectional views sequentially showing the manufacturing process of the wireless IC device 103.

  First, as shown in (1) in FIG. 13, the wiring board 1 is prepared. Specifically, conductor patterns 91 and 92 and mounting electrodes 81 and 82 (land patterns) for mounting RFIC are formed on the first main surface PS1 of the wiring board 1. Further, in the thickness direction of the wiring board 1, an interlayer connection conductor V <b> 1 connected to the conductor patterns 91 and 92 and formed inside the wiring board 1 is formed.

  Thereafter, the conductive bonding material 4 such as solder paste is formed on the mounting electrodes 81 and 82 for mounting the RFIC, the conductor patterns 91 and 92 for mounting the metal posts, and the like. At this time, no conductor pattern is formed on the second main surface PS2 side of the wiring board 1.

  Next, as shown in (2) in FIG. 13, the wiring board 1 is mounted on a support base 7 having an adhesive layer or the like. As for the wiring board 1, the 2nd main surface PS2 side is mounted in the support stand 7 through the adhesion layer. Thereby, the wiring board 1 is mounted in a state of being firmly fixed to the support base 7.

  Next, as shown in (3) in FIG. 13, the RFIC 3, the plurality of small-diameter bridge-like conductors Sb2, and the like are each mounted on the wiring board 1 via a conductive bonding material such as solder. Specifically, after mounting the RFIC 3 on the first main surface PS1 of the wiring board 1 with a mounter, the RFIC 3 is soldered by a reflow process. In addition, after mounting the first end and the second end of the plurality of small-diameter bridge conductors Sb2 and the like on the first main surface PS1 of the wiring board 1, the plurality of small-diameter bridge conductors Sb2 and the like are soldered by a reflow process. Attach. By this step, the RFIC 3, the small diameter bridge conductor Sb2, and the like are electrically connected to the wiring board 1 and structurally joined.

  Each of the plurality of small-diameter bridge-like conductors is a series of metal members, for example, a Cu wire having a circular cross section bent in an inverted U shape. The plurality of small-diameter bridge-like conductors are not limited to those containing Cu as the main component, but those containing Cu as the main component are preferable in terms of conductivity and workability.

  Thereafter, as shown in (4) in FIG. 13, the first end and the second end of the plurality of large-diameter bridge conductors Bb2 and the like are mounted on the support base 7 side in an upright state. Thereby, the plurality of large-diameter bridge conductors Bb2 and the like are mounted in a state of being firmly fixed to the support base 7.

  Each of the plurality of large-diameter bridge-shaped conductors is a series of metal members, for example, a Cu wire having a circular cross section bent in an inverted U shape. The plurality of large-diameter bridge-shaped conductors are not limited to those having Cu as a main component, but those having Cu as a main component are preferable in terms of conductivity and workability.

  Next, as shown in (5) in FIG. 14, the resin member 10 is formed (covered with resin) to a height at which the RFIC 3, the large-diameter bridge conductor Bb2, the small-diameter bridge conductor Sb2, and the like are embedded. Specifically, an epoxy resin or the like is applied to a predetermined height (more than the height of the RFIC 3, the large-diameter bridge conductor Bb2, the small-diameter bridge conductor Sb2, etc.).

  The resin member 10 may be provided by application of a liquid resin, or may be provided by stacking semi-cured sheet-like resins.

  Next, as shown in (5) and (6) in FIG. 14, the support base 7 is removed from the resin member 10 and the wiring board 1 etc., and both ends (first end and second end of the large-diameter bridge-shaped conductor Bb2 etc.) are removed. And the interlayer connection conductor V1 are exposed from the surface of the resin member 10 and the wiring board 1. Specifically, the resin member 10 is polished (or cut) in a planar manner to the polishing line PL2 indicated by (5) in FIG. 14 together with the support base 7, the wiring board 1, the large-diameter bridge conductor Bb2, and the like. Thus, both ends of the plurality of large-diameter bridge conductors Bb2 and the interlayer connection conductor V1 are exposed from the second main surface PS2 of the wiring board 1 and the second surface VS2 of the resin member 10.

  Next, as shown in (7) in FIG. 14, conductor patterns 71, 72 and the like are formed on the second surface VS <b> 2 of the resin member 10 and the second main surface PS <b> 2 of the wiring board 1. Thereafter, a plating film is formed on the conductor patterns 71, 72, etc. by plating with Cu or the like.

  Then, if necessary, a protective resin film (for prevention of oxidation) is formed on the formation surfaces of the conductor patterns 71 and 72 formed on the outer surface (second main surface PS2) of the wiring board 1 and the second surface VS2 of the resin member 10. A solder resist film).

  In addition, said process is processed with a mother substrate state. Finally, the mother board is separated into individual wireless IC device 103 units (pieces).

  Further, another wireless IC device 103A according to the present embodiment is manufactured by, for example, the following process. 15 and 16 are cross-sectional views sequentially showing the manufacturing process of the wireless IC device 103A.

  First, as shown in (1) in FIG. 15, an element body 300A is prepared. The element body 300A is the same as the element body 300A shown in the first embodiment.

  Next, as shown in (2) in FIG. 15, the element body 300A is mounted on the support base 7 having an adhesive layer or the like. In the element body 300A, the second main surface PS2 side of the wiring board 1 is mounted on the support base 7 via an adhesive layer. Thereby, the wiring board 1 is mounted in a state of being firmly fixed to the support base 7.

  Thereafter, as shown in (3) of FIG. 15, the first end and the second end of the large-diameter bridge conductor Bb2 and the like are mounted on the support base 7 side in an upright state. Thereby, the large-diameter bridge-like conductor Bb2 and the like are mounted in a state of being firmly fixed to the support base 7.

  Next, as shown in (4) in FIG. 16, the resin member 10A is formed (covered with resin) to a height at which the large-diameter bridge conductor Bb2 and the like and the element body 300A are embedded. Specifically, an epoxy resin or the like is applied to a predetermined height (the height of the large-diameter bridge-like conductor Bb2 or the like and the element body 300A).

  Next, as shown in (4) and (5) in FIG. 16, the support base 7 is removed from the resin member 10 and the wiring board 1 and the like, and both ends (first and second ends) of the large-diameter bridge-shaped conductor Bb2 and the like. End) and the interlayer connection conductor V1 are exposed from the surface of the resin member 10 and the wiring board 1. Specifically, the resin member 10 is polished (or cut) in a planar manner to the polishing line PL2 indicated by (4) in FIG. 16 together with the support base 7, the wiring board 1, the large-diameter bridge conductor Bb2, and the like. As a result, both ends of the large-diameter bridge conductor Bb2 and the interlayer connection conductor V1 are exposed from the second main surface PS2 of the wiring board 1 and the second surface VS2 of the resin member 10.

  Next, as shown in (6) in FIG. 16, conductor patterns 71, 72 and the like are formed on the second surface VS <b> 2 of the resin member 10 and the second main surface PS <b> 2 of the wiring board 1. Thereafter, a plating film is formed on the conductor patterns 71, 72, etc. by plating with Cu or the like.

  Then, if necessary, a protective resin film (for prevention of oxidation) is formed on the formation surfaces of the conductor patterns 71 and 72 formed on the outer surface (second main surface PS2) of the wiring board 1 and the second surface VS2 of the resin member 10. A solder resist film).

  In addition, said process is processed with a mother substrate state. Finally, the mother board is separated into individual wireless IC device 103A units (pieces).

  Note that, as in the wireless IC device 103A shown in the present embodiment, any one of the plurality of large-diameter bridge conductors and the plurality of small-diameter bridge conductors may be a series of metal members.

  In the present embodiment, an example of the wireless IC device 103 including the resin member 10 has been described, but the present invention is not limited to this configuration. As with the wireless IC device 101 according to the first embodiment, the wireless IC device 103 in which the plurality of large-diameter bridge-shaped conductors and the plurality of small-diameter bridge-shaped conductors are a series of metal members does not include the resin member 10. There may be. Further, when the plurality of large-diameter bridge-shaped conductors are a series of metal members as in the wireless IC device 103A, a configuration without the resin member 10A may be used.

<< Fourth Embodiment >>
In the fourth embodiment, an example in which the structures of the large-diameter bridge-like conductor and the small-diameter bridge-like conductor are different from those of the wireless IC device 103 according to the third embodiment is shown. Other configurations are substantially the same as those of the wireless IC device 103.

  FIG. 17 is a cross-sectional view of the wireless IC device 104 according to the fourth embodiment.

  As shown in FIG. 17, a plurality of large diameter bridge conductors (in FIG. 17, the large diameter bridge conductor Bb2 appears) and a plurality of small diameter bridge conductors (in FIG. 17, the small diameter bridge conductor Sb2 appears). Is an arc-shaped (or inverted U-shaped) conductor.

  Therefore, the wireless IC device 104 according to the present embodiment does not include the first columnar metal part, the second columnar metal part, the third columnar metal part, and the fourth columnar metal part.

  Even in such a configuration, the basic configuration of the wireless IC device 104 is the same as that of the wireless IC device 103 according to the third embodiment, and the same operations and effects as the wireless IC device 103 are achieved.

<< Fifth Embodiment >>
The fifth embodiment is different from the wireless IC device 103 according to the third embodiment in that the second wiring board 2 and conductor patterns 73, 74, 75 and the like formed on the second wiring board 2 are further provided. Other configurations are substantially the same as those of the wireless IC device 103.

  18A is a cross-sectional view of the wireless IC device 105 according to the fifth embodiment, and FIG. 18B is a cross-sectional view of a different part of the wireless IC device 105.

  Conductor patterns 73, 74, 75, etc. are formed on the third main surface of the second wiring board 2 (the upper surface of the second wiring board 2 in FIG. 18). By mounting the second main surface of the wiring board 1 on the third main surface of the second wiring board 2, both ends of the large-diameter loop connection conductor are formed on the third main surface of the second wiring board 2. Connected to conductor pattern. Both ends of the large-diameter bridge-like conductor are connected to a conductor pattern formed on the third main surface of the second wiring board 2 via a conductive bonding material such as solder.

  In the present embodiment, the large-diameter loop connection conductor includes a conductor pattern formed on the first main surface PS1 of the wiring board 1, an interlayer connection conductor formed inside the wiring board 1, and the third wiring board 2 of the second wiring board 2. It is composed of a conductor pattern formed on the main surface. For example, the large-diameter loop connection conductor Bj2 includes a conductor pattern 91 formed on the first main surface PS1 of the wiring board 1 and an interlayer connection conductor V1 formed inside the wiring board 1, as shown in FIG. , And a conductor pattern 74 formed on the third main surface of the second wiring board 2.

  In the present embodiment, the small-diameter loop connection conductor includes a conductor pattern formed on the first main surface PS1 of the wiring board 1, an interlayer connection conductor formed inside the wiring board 1, and a third main wiring board of the second wiring board 2. It is composed of a conductor pattern formed on the surface. For example, the small-diameter loop connection conductor Sj1 includes a conductor pattern 92 formed on the first main surface PS1 of the wiring board 1, an interlayer connection conductor V2 formed inside the wiring board 1, as shown in FIG. And a conductor pattern 73 formed on the third main surface of the second wiring board 2.

  Even in such a configuration, the basic configuration of the wireless IC device 105 is the same as that of the wireless IC device 103 according to the third embodiment, and has the same operations and effects as the wireless IC device 103.

  In the present embodiment, the conductor pattern 74 formed on the third main surface of the second wiring board 2 is used as a part of the large-diameter loop connection conductor. However, the present invention is not limited to this. It is not a thing. The conductor pattern formed on the fourth main surface of the second wiring board 2 (the lower surface of the second wiring board 2 in FIG. 18), the conductor pattern formed inside the second wiring board 2, or the interlayer connection conductor has a large diameter. You may utilize for a part of loop connection conductor. The same applies to the small-diameter loop connection conductor.

<< Other Embodiments >>
In each of the above-described embodiments, the configuration example in which the winding axes AX of the plurality of large-diameter loops and the winding shafts of the plurality of small-diameter loops coincide with each other has been described. . The winding axes of the plurality of small-diameter loops do not need to completely coincide with the winding axis AX (Y-axis direction) of the plurality of large-diameter loops, and may be along the Y-axis direction. In addition, the state “along” in the first direction in the present invention means, for example, that the winding axis of the small-diameter loop is within a range of 0 ° to less than ± 45 ° with respect to the first direction (Y-axis direction).

  In each of the above-described embodiments, the small-diameter bridge-shaped conductor is shown inside the large-diameter bridge-shaped conductor as viewed from the Y-axis direction. However, the present invention is not limited to this. Absent. The inner and outer diameter dimensions of the small-diameter bridge-shaped conductor need only be smaller than the inner and outer diameter dimensions of the large-diameter bridge-shaped conductor as viewed from the Y-axis direction, and a part of the small-diameter bridge-shaped conductor has a large diameter as viewed from the Y-axis direction. It may overlap the bridge-like conductor.

  In each of the embodiments described above, the configuration in which the RFIC 3 is mounted on the first main surface PS1 of the wiring board 1 has been described. However, the present invention is not limited to this. The RFIC 3 may be mounted on the second main surface PS2 of the wiring board 1, for example, or may be built in the wiring board 1. Further, a configuration may be adopted in which a cavity is formed in either the first main surface PS1 or the second main surface PS2 of the wiring board 1, and the RFIC is accommodated in the cavity.

  Furthermore, in each embodiment shown above, although the radio | wireless IC device provided with RFIC and a coil device was shown, it is not limited to this structure. For example, a DC / DC converter module can be configured by providing a chip capacitor and an integrated circuit element for a DC / DC converter on the first main surface of the wiring board 1 provided in the coil device.

  Finally, the scope of the present invention is shown not by the embodiments described above but by the claims. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope equivalent to the claims.

AX ... winding axis CD1, CD2 of large-diameter loop ... coil device E1 ... first end E2 of coil device ... second end BC of coil device ... large-diameter coil Be1 ... first end Be2 of large-diameter coil ... large-diameter coil The second end SC of the small-diameter coil Se1, the first end Se2 of the small-diameter coil, the second ends BL1, BL2, BL3, BL4 of the small-diameter coil, the large-diameter loops Bb1Bb2, Bb3, Bb4, the large-diameter bridge conductors Bj1, Bj2, Bj3, Bj4: Large diameter loop connection conductors SL1, SL2, SL3, SL4 ... Small diameter loops Sb1, Sb2, Sb3, Sb4 ... Small diameter bridge conductors Sj1, Sj2, Sj3 ... Small diameter loop connection conductors BFE ... Large diameter loop in the first direction Forming area SFE ... small diameter loop forming area 1 in the first direction ... wiring board 2 ... second wiring board 3 ... RFIC
4 ... conductive bonding material 7 ... supports PL1, PL2 ... polishing wire PS1 ... first main surface PS2 of wiring board ... second main surface V1, V2 of wiring board ... interlayer connection conductor VS1 ... first surface VS2 of resin member ... 2nd surface 10, 10A, 10B of resin member ... Resin member 11, 12, 13, 14 ... 1st metal post 21, 22, 23, 24 ... 2nd metal post 31, 32, 33, 34 ... 3rd metal Posts 41, 42, 43, 44 ... fourth metal posts 51, 52, 53, 54 ... large diameter connection conductors 61, 62, 63, 64 ... small diameter connection conductors 71, 72, 73, 74, 75 ... conductor pattern 81, 82 ... Mounting electrodes 91, 92 ... Conductor patterns 101, 103, 103A, 104, 105 ... Wireless IC device 300A ... Element

Claims (14)

A large-diameter loop having a winding axis in the first direction and including a large-diameter bridge-shaped conductor;
A small-diameter loop having a winding axis along the first direction, and including a small-diameter bridge-like conductor disposed inside the outer diameter of the large-diameter loop as viewed from the first direction;
A wiring board having a first main surface and a second main surface that are at least partially disposed inside the large-diameter loop and are parallel to the first direction, as viewed from the first direction;
With
The large diameter loop is connected to the small diameter loop,
The large-diameter bridge-shaped conductor and the small-diameter bridge-shaped conductor are non-parallel to the first main surface,
The small-diameter bridge-shaped conductor is mounted on the first main surface,
The coil device, wherein the first end and the second end of the large-diameter bridge-shaped conductor are disposed outside the wiring board. A resin member;
The coil device according to claim 1, wherein at least a part of the large-diameter loop, the small-diameter loop, and the wiring board is embedded in a resin member.   The coil device according to claim 2, wherein the wiring board is disposed such that the first main surface is embedded inside the resin member and the second main surface is exposed from the resin member. The large-diameter loop includes a large-diameter loop connection conductor connected to a first end or a second end of the large-diameter bridge-shaped conductor,
The small-diameter loop includes a small-diameter loop connection conductor connected to the first end or the second end of the small-diameter bridge-shaped conductor,
At least a part of the large-diameter loop connection conductor is formed inside the wiring board or the second main surface,
The coil device according to any one of claims 1 to 3, wherein the small-diameter loop connection conductor is formed inside the wiring board or on the first main surface. The large-diameter bridge-shaped conductor has a first columnar metal part and a second columnar metal part extending in a direction orthogonal to the first main surface, and a large-diameter connection conductor,
The large-diameter connection conductor connects between the first end of the first columnar metal part and the first end of the second columnar metal part,
The coil device according to any one of claims 1 to 4, wherein the first columnar metal part and the second columnar metal part are arranged outside the wiring board. The small-diameter bridge-shaped conductor has a third columnar metal portion and a fourth columnar metal portion extending in a direction orthogonal to the first main surface, and a small-diameter connection conductor,
The small-diameter connection conductor connects between the first end of the third columnar metal part and the first end of the fourth columnar metal part,
The coil according to any one of claims 1 to 5, wherein a second end of the third columnar metal part and a second end of the fourth columnar metal part are respectively mounted on the first main surface of the wiring board. device.   The coil device according to any one of claims 1 to 6, wherein the large-diameter bridge-shaped conductor is a series of metal members.   The coil device according to claim 1, wherein the small-diameter bridge-shaped conductor is a series of metal members.   9. The coil according to claim 1, wherein the large-diameter bridge-shaped conductor and the small-diameter bridge-shaped conductor are arranged without a gap along the first direction in a plan view of the first main surface. device.   The large-diameter bridge-like conductor and the small-diameter bridge-like conductor are arranged without a gap along the first direction when viewed from a direction parallel to the first main surface and a direction orthogonal to the first direction. The coil device according to any one of claims 1 to 9.   The coil device according to any one of claims 1 to 10, wherein the large-diameter loop and the small-diameter loop are alternately arranged in the first direction and are alternately connected in order to form a helical coil. . The number of the large diameter loops and the number of the small diameter loops are plural,
The plurality of large-diameter loops are connected to each other to form a helical large-diameter coil,
The plurality of small-diameter loops are connected to each other to form a helical small-diameter coil,
The coil device according to claim 1, wherein the large-diameter coil is connected to the small-diameter coil. The extending direction from the first end to the second end of the large-diameter coil in the first direction is opposite to the extending direction from the first end to the second end of the small-diameter coil in the first direction. ,
A second end of the large diameter coil is connected to a first end of the small diameter coil;
The coil device according to claim 12, wherein at least a part of a formation area of the large-diameter coil in the first direction overlaps with a formation area of the small-diameter coil in the first direction. A coil device according to any one of claims 1 to 13,
RFIC mounted on the wiring board;
With
The coil device is a wireless IC device connected to an antenna port of the RFIC.

Images