Coil component and card equipped therewith
The coil component with magnetic bodies and a coil conductor structure addresses the reduced coupling issue by enhancing the magnetic coupling between the IC module and the coil conductor, improving communication efficiency.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TDK CORP
- Filing Date
- 2024-12-26
- Publication Date
- 2026-07-08
Smart Images
Figure 2026113905000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a coil component and a card including the same.
Background Art
[0002] Patent Document 1 discloses a card including a metal layer having a through hole, an IC module disposed in the through hole of the metal layer and having a chip antenna, an antenna that is RF-coupled to the chip antenna, and a ferrite layer disposed between the IC module and the antenna and having a through hole provided in a portion overlapping the chip antenna.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, in the structure described in Patent Document 1, there is a problem that the coupling between the antenna and the chip antenna of the IC module is reduced mainly due to the influence of the metal layer.
[0005] The present disclosure describes a technique for suppressing the influence of metal in a coil component including a magnetic material and a coil.
Means for Solving the Problems
[0006] A coil component according to an embodiment of the present disclosure includes a first magnetic body having a through hole, a second magnetic body overlapping the through hole of the first magnetic body, and a coil conductor positioned between the first magnetic body and the second magnetic body. The coil conductor includes a first turn portion, at least a part of an opening region of the first turn portion of the coil conductor overlaps the through hole of the first magnetic body, and at least a part of the conductor of the first turn portion of the coil conductor overlaps the second magnetic body.
Effects of the Invention
[0007] According to this disclosure, a technique is provided for suppressing the influence of metal in a coil component including a magnetic material and a coil. [Brief explanation of the drawing]
[0008] [Figure 1] Figure 1 is a schematic perspective view showing the external appearance of an IC card 2 equipped with a coil component according to one embodiment of the present disclosure. [Figure 2] Figure 2 is an exploded perspective view illustrating the structure of an IC card 2 equipped with a coil component 1. [Figure 3] Figure 3 is a schematic cross-sectional view illustrating the structure of an IC card 2 equipped with a coil component 1. [Figure 4] Figure 4 is a schematic plan view illustrating the configuration of the coil pattern CP. [Figure 5] Figure 5 is a schematic cross-sectional view along the CC line shown in Figure 4. [Figure 6] Figure 6 is a schematic perspective view of the IC module 60 as seen from the back side. [Figure 7] Figure 7 is a schematic diagram showing the state in which the IC card 2 and the card reader 6 are communicating. [Figure 8] Figures 8(a) to 8(e) are schematic cross-sectional views showing several examples of the shape and positional relationship of the first magnetic material 31, the second magnetic material 32, and the first circular portion 71 of the coil pattern CP in the coil component 1 according to this embodiment. [Figure 9] Figure 9 is a schematic cross-sectional view illustrating the structure of an IC card 3 equipped with a coil component 1a according to a modified example. [Figure 10] Figure 10 is a schematic plan view illustrating the configuration of the coil pattern CP included in coil component 1a according to a modified example. [Figure 11] Figures 11(a) to (d) are schematic cross-sectional views showing several examples of the shape and positional relationship of the first magnetic material 31, the second magnetic material 32, and the first circular portion 71 of the coil pattern CP in a modified coil component 1a. [Figure 12] Figures 12(a) to (e) are schematic cross-sectional views showing the structure of the coil components in samples A to E, respectively. [Figure 13] Figure 13 is a table showing the evaluation results for samples A through E. [Modes for carrying out the invention]
[0009] The embodiments of this disclosure will be described in detail below with reference to the attached drawings.
[0010] Figure 1 is a schematic perspective view showing the external appearance of an IC card 2 equipped with a coil component according to one embodiment of the present disclosure.
[0011] The IC card 2 shown in Figure 1 is a plate-like body with the Y direction as the longitudinal direction, the X direction as the short direction, and the Z direction as the thickness direction, and has an upper surface 2a and a back surface 2b that constitute the XY plane. An IC module, which will be described later, is built into the IC card 2, and the terminal electrodes E of the IC module are exposed on the upper surface 2a of the IC card 2.
[0012] Figures 2 and 3 are a substantially exploded perspective view and a substantially cross-sectional view, respectively, illustrating the structure of the IC card 2 equipped with the coil component 1 according to this embodiment.
[0013] The IC card 2 shown in Figures 2 and 3 has a structure in which a plastic plate 10, a second magnetic material 32, a coil pattern CP, a first magnetic material 31, and a metal plate 40 are stacked in this order from the back surface 2b to the top surface 2a. The coil pattern CP and the second magnetic material 32 are supported by an insulating layer 21, the first magnetic material 31 is supported by an insulating layer 23, and the insulating layer 21 and the insulating layer 23 are bonded together via an insulating layer 22.
[0014] The plastic plate 10 is made of a resin material that does not obstruct magnetic flux. The outer surface of the plastic plate 10 constitutes the back surface 2b of the IC card 2. The metal plate 40 is made of a metal material such as stainless steel or titanium. The outer surface of the metal plate 40 constitutes the upper surface 2a of the IC card 2. An IC module 60 is disposed inside the through hole 41 provided in the metal plate 40. Thus, the IC card 2 is a card in which a metal plate is used for the main body. The metal plate 40 constitutes the first card base material, and the plastic plate 10 constitutes the second card base material.
[0015] The coil component 1 according to the present embodiment is composed of a first magnetic body 31, a second magnetic body 32, and a coil pattern CP. The coil component 1 is disposed between the plastic plate 10 and the metal plate 40 such that the first magnetic body 31 faces the metal plate 40 and the second magnetic body 32 faces the plastic plate 10.
[0016] The coil pattern CP includes a first turn portion 71 and a second turn portion 72. In the example shown in FIG. 3, a part of the first turn portion 71 is embedded in the insulating layer 21. Also, in the example shown in FIG. 3, a part of the second turn portion 72 is embedded in the insulating layer 21, and the remaining part of the second turn portion 72 is embedded in the insulating layer 22. The insulating layer 21 is made of, for example, an acrylic resin, the insulating layer 22 is made of, for example, a urethane resin, and the insulating layer 23 is made of, for example, a PET (polyethylene terephthalate) resin.
[0017] The first magnetic material 31 and the metal plate 40 are provided with through holes 31a and 41, respectively. These through holes 31a and 41 overlap in the Z direction, which is the stacking direction. At least a portion of the opening region 71a of the first circumferential portion 71 of the coil pattern CP overlaps with the through holes 31a of the first magnetic material 31 and the through holes 41 of the metal plate 40. The opening region 71a of the first circumferential portion 71 is a region corresponding to the inner diameter of the first circumferential portion 71 and is located inside the innermost circumferential turn of the first circumferential portion 71. Through holes may also be provided in the insulating layers 22 and 23 at positions overlapping with the through holes 31a and 41. The plastic plate 10 and the insulating layer 21 are bonded via an adhesive layer 51. The metal plate 40 and the first magnetic material 31 are bonded via an adhesive layer 52. Examples of materials for the adhesive layers 51 and 52 include acrylic double-sided tape, thermosetting resin, and thermoplastic resin.
[0018] The second magnetic material 32 is positioned to overlap with the through-hole 31a of the first magnetic material 31 and the through-hole 41 of the metal plate 40, so as to overlap with at least a portion of the conductor pattern constituting the first circular portion 71 of the coil pattern CP. The first magnetic material 31 and the second magnetic material 32 may be sheet-like members made of the same material. In the example shown in Figure 3, a gap corresponding to the thickness of the second magnetic material 32 is shown between the adhesive layer 51 and the insulating layer 21, but in areas where the second magnetic material 32 is not present, the adhesive layer 51 and the insulating layer 21 may be in close contact.
[0019] Figure 4 is a schematic plan view illustrating the configuration of the coil pattern CP. Note that line AA in Figure 4 indicates the cross-sectional position shown in Figure 3.
[0020] The coil pattern CP shown in Figure 4 is composed of a conductor pattern consisting of multiple turns. Both the outer peripheral end CPa and the inner peripheral end CPb of the coil pattern CP are open and not connected to any other conductive members. Therefore, the coil pattern CP is electrically floating. The coil pattern CP may also be composed of a coated conductor, where the core conductor is covered with an insulating coating such as resin.
[0021] Each of the multiple turns constituting the coil pattern CP has a second circumferential portion 72 that circulates along the outer edge of the first magnetic material 31 so as to overlap with the first magnetic material 31, a first circumferential portion 71 located in the opening region 72a surrounded by the second circumferential portion 72 and circulating in the opposite direction to the second circumferential portion 72, and connecting portions 73, 74 that connect the first circumferential portion 71 and the second circumferential portion 72. The opening region 72a of the second circumferential portion 72 is a region corresponding to the inner diameter of the second circumferential portion 72 and is a region located inside the innermost circumferential turn of the second circumferential portion 72. The coil pattern CP may have one or more turns that do not include one or both of the first circumferential portion 21 and the second circumferential portion 22. Here, if we define position B shown in Figure 4 as the start and end points of each turn, then one end of the first loop section 71 and one end of the second loop section 72 in each turn are connected via the first connecting section 73, and the other end of the first loop section 71 in each turn and the other end of the second loop section 72 of another turn adjacent to that turn are connected via the second connecting section 74.
[0022] In the example shown in Figure 4, the number of turns in the conductor pattern constituting the coil pattern CP is approximately 3 turns. The first circular portion 71 of the coil pattern CP is a part that protrudes toward the opening region 72a surrounded by the second circular portion 72 of the coil pattern CP. In other words, each turn of the coil pattern CP is composed of a second circular portion 72 of less than 1 turn, a first circular portion 71 of less than 1 turn, and a first connecting portion 73 and a second connecting portion 74 that connect them.
[0023] In the examples shown in Figures 3 and 4, the conductor pattern constituting the first circular portion 71 of the coil pattern CP overlaps with the through-hole 31a of the first magnetic material 31. As a result, the first circular portion 71 of the coil pattern CP overlaps with the IC module 60 placed in the through-hole 41 of the metal plate 40 in the Z direction via the through-hole 31a of the first magnetic material 31. In the example shown in Figure 4, since the first circular portion 71 of the coil pattern CP is approximately circular and the edge of the through-hole 31a of the first magnetic material 31 is approximately square, the first circular portion 71 of the coil pattern CP does not follow the edge of the through-hole 31a of the first magnetic material 31. As a result, the first circular portion 71 of the coil pattern CP is less affected by the metal plate 40 via the through-hole 31a of the first magnetic material 31, and losses due to the metal plate 40 are reduced.
[0024] The second loop portion 72 of the coil pattern CP functions as an antenna coil that connects to an external card reader during actual use. The first loop portion 71 of the coil pattern CP functions as a coupling coil that connects to the IC module 60. The first loop portion 71 of the coil pattern CP may also function as an antenna coil that connects to the card reader. For example, if the resonant frequency of the coil pattern CP is set to a frequency band of 13.56 MHz or near 13.56 MHz, near-field communication (NFC) becomes possible between an external card reader and the IC card 2. [0] Furthermore, if the outer peripheral end CPa of the coil pattern CP is taken as the starting point and the inner peripheral end CPb of the coil pattern CP is taken as the ending point, when viewed from the direction shown in Figure 4, the second loop portion 72 of the coil pattern CP rotates clockwise, and the first loop portion 71 of the coil pattern CP rotates counterclockwise. In other words, the directions of rotation of the first circulating section 71 and the second circulating section 72 are opposite to each other. As a result, for example, in turn 721 where the second circulating section 72 is located on the outermost circumference of each turn, the first circulating section 71 will be located on the innermost circumference of each turn.
[0025] As shown in Figure 3, in this embodiment, the second magnetic material 32 is provided at a position that overlaps with the first circular portion 71 of the coil pattern CP in a plan view from the Z direction. The second magnetic material 32 is locally arranged at a position that overlaps with the conductor pattern constituting the first circular portion 71 of the coil pattern CP, and with the opening region 71a of the first circular portion 71 of the coil pattern CP, and does not overlap with the conductor pattern constituting the second circular portion 72 of the coil pattern CP. In the example shown in Figure 3, the first magnetic material 31 and the second magnetic material 32 do not overlap, but it is acceptable for parts of them to overlap. The second magnetic material 32 can increase the inductance of the first circular portion 71 of the coil pattern CP.
[0026] Figure 5 is a schematic cross-sectional view along the CC line shown in Figure 4.
[0027] In the example shown in Figure 5, the coil pattern CP is composed of a main body 81 which is a metal layer and a seed portion 82 which is a conductive resin layer. The surface S1 located in the +Z direction of the coil pattern CP is made of the main body 81, and the surface S2 located in the -Z direction of the coil pattern CP is made of the seed portion 82. A part of the main body 81 is embedded in the insulating layer 21. In the portion of the coil pattern CP that constitutes the first circumference 71, the seed portion 82 is exposed. The seed portion 82, which is a conductive resin layer, has a higher electrical resistance than the main body 81 which is a metal layer. Therefore, by making the surface S2 of the coil pattern CP exposed from the insulating layer 21 out of the seed portion 82 which is a conductive resin layer, the occurrence of short-circuit failures between the first circumference 71 of the coil pattern CP and the IC module 60 is suppressed. On the other hand, in the portion of the coil pattern CP that constitutes the second circumference 72, the remaining part of the main body 81 and the seed portion 82 are embedded in the insulating layer 22.
[0028] Figure 6 is a schematic perspective view of the IC module 60 as seen from the back side.
[0029] As shown in Figure 6, the IC module 60 comprises a module substrate 61, an IC chip 62 mounted or embedded on the module substrate 61, and a coupling coil 63. The IC chip 62 is protected by being covered with a dome-shaped protective resin 64. The protective resin 64 is made of an insulating material. Terminal electrodes E, as shown in Figure 1, are provided on the surface side of the module substrate 61. The IC module 60 having this configuration is housed in a through hole 41 provided in the metal plate 40. When the IC module 60 is housed in the through hole 41, the coupling coil 63 of the IC module 60 and the first circular portion 71 of the coil pattern CP are magnetically coupled. Since the first circular portion 71 of the coil pattern CP that is magnetically coupled with the coupling coil 63 is connected to the second circular portion 72 of the coil pattern CP which functions as an antenna coil, communication between the IC module 60 and the outside becomes possible via the coil pattern CP.
[0030] As a result, as shown in Figure 7, by placing the back side 2b of the IC card 2 facing the card reader 6, communication can be established between the card reader 6 and the IC chip 62. In other words, the card reader 6 is coupled to the coupling coil 63 of the IC module 60 via the coil pattern CP, thereby enabling communication with the IC chip 62.
[0031] Furthermore, in this embodiment, since the second magnetic material 32 is provided at a position overlapping with the first circular portion 71 of the coil pattern CP, the coupling between the coupling coil 63 of the IC module 60 and the first circular portion 71 of the coil pattern CP is enhanced. Moreover, since the second magnetic material 32 is locally arranged at a position overlapping with the first circular portion 71 of the coil pattern CP, and the second magnetic material 32 is not provided at a position overlapping with the second circular portion 72 of the coil pattern CP, it is possible to suppress interference with communication between the second circular portion 72 of the coil pattern CP, which functions as an antenna coil, and the card reader 6.
[0032] Figures 8(a) to 8(e) are schematic cross-sectional views showing several examples of the shape and positional relationship of the first magnetic material 31, the second magnetic material 32, and the first circular portion 71 of the coil pattern CP in the coil component 1 according to this embodiment.
[0033] In the example shown in Figure 8(a), the planar positions of the inner circumference edge of the through hole 31a of the first magnetic material 31, the outer circumference edge of the second magnetic material 32, and the outer circumference edge of the outermost turn of the first circumference portion 71 of the coil pattern CP are approximately coincidental. In this case, the opening region 71a of the first circumference portion 71 of the coil pattern CP and the entire conductor pattern constituting the first circumference portion 71 overlap with the through hole 31a of the first magnetic material 31 and the second magnetic material 32. The thickness T1 of the first magnetic material 31 and the thickness T2 of the second magnetic material 32 may be approximately the same. The distance L2 between the second magnetic material 32 and the conductor pattern constituting the first circumference portion 71 of the coil pattern CP may be shorter than the distance L1 between the first magnetic material 31 and the conductor pattern constituting the first circumference portion 71 of the coil pattern CP. According to this, the effect of improving the inductance by the second magnetic material 32 is enhanced, and the decrease in coupling between the coupling coil 63 of the IC module 60 and the first circular portion 71 of the coil pattern CP, which is caused by the presence of the first magnetic material 31, is suppressed. In this example, the second magnetic material 32 overlaps with each turn of the first circular portion 71, but it is acceptable if it does not overlap with a portion of the outermost turn.
[0034] In the example shown in Figure 8(b), the planar size of the second magnetic material 32 is enlarged compared to the example shown in Figure 8(a). As a result, the second magnetic material 32 includes not only the portion that overlaps with the opening region 71a of the first circular portion 71 of the coil pattern CP and the conductor pattern constituting the first circular portion 71, but also the portion that overlaps with the outer region of the first circular portion 71 of the coil pattern CP. Therefore, the second magnetic material 32 includes the portion located outside the outermost turn of the first circular portion 71 of the coil pattern CP. Furthermore, the portion of the second magnetic material 32 that overlaps with the outer region of the first circular portion 71 of the coil pattern CP also overlaps with the first magnetic material 31.
[0035] In the example shown in Figure 8(c), the planar size of the second magnetic material 32 is reduced compared to the example shown in Figure 8(a). As a result, a portion of the conductor pattern constituting the first circular portion 71 of the coil pattern CP does not overlap with the second magnetic material 32. Furthermore, the size of the second magnetic material 32 is smaller than the size of the through-hole 31a of the first magnetic material 31, so that the first magnetic material 31 and the second magnetic material 32 do not overlap.
[0036] In the example shown in Figure 8(d), the planar size of the through-hole 31a of the first magnetic material 31 is enlarged compared to the example shown in Figure 8(a). As a result, the through-hole 31a of the first magnetic material 31 has a portion that does not overlap with the second magnetic material 32 and the first peripheral portion 71 of the coil pattern CP.
[0037] In the example shown in Figure 8(e), the thickness T2 of the second magnetic material 32 is reduced compared to the example shown in Figure 8(a). As a result, the thickness T2 of the second magnetic material 32 is thinner than the thickness T1 of the first magnetic material 31. By reducing the thickness of the locally placed second magnetic material 32, the flatness of the coil component 1 can be maintained, and when the coil component 1 is sandwiched between the metal plate 40 and the plastic plate 10 via the adhesive layers 51 and 52, steps are less likely to occur within the card.
[0038] In any of the structures shown in Figures 8(a) to 8(e), the inductance of the first circular portion 71 of the coil pattern CP is increased by providing the second magnetic material 32. This makes it possible to suppress the decrease in coupling between the first circular portion 71 of the coil pattern CP and the coupling coil 63 of the IC module 60 due to the influence of the metal plate 40.
[0039] Figure 9 is a schematic cross-sectional view illustrating the structure of an IC card 3 equipped with a modified coil component 1a. Figure 10 is a schematic plan view illustrating the configuration of the coil pattern CP included in the modified coil component 1a. The DD line shown in Figure 10 indicates the cross-sectional position in Figure 9.
[0040] The coil pattern CP shown in Figures 9 and 10 differs from the coil pattern CP shown in Figures 3 and 4 in that the diameter of the first circular portion 71 is enlarged, so that a portion of the conductor pattern constituting the first circular portion 71 overlaps with the first magnetic material 31, and the planar size of the second magnetic material 32 is also enlarged, so that a portion of the second magnetic material 32 overlaps with the first magnetic material 31. With this configuration, a portion of the conductor pattern constituting the first circular portion 71 of the coil pattern CP overlaps with both the first magnetic material 31 and the second magnetic material 32.
[0041] As illustrated by the coil pattern CP shown in Figures 9 and 10, a portion of the conductor pattern constituting the first circular portion 71 and a portion of the second magnetic material 32 may overlap with the first magnetic material 31. This makes it possible to further increase the inductance of the first circular portion 71 of the coil pattern CP.
[0042] Figures 11(a) to (d) are schematic cross-sectional views showing several examples of the shape and positional relationship of the first magnetic material 31, the second magnetic material 32, and the first circular portion 71 of the coil pattern CP in a modified coil component 1a.
[0043] In the example shown in Figure 11(a), the outer edge of the second magnetic material 32 and the planar position of the outer edge of the outermost turn of the first circular portion 71 of the coil pattern CP are approximately coincidental. In this case, the opening region 71a of the first circular portion 71 of the coil pattern CP and the entire conductor pattern constituting the first circular portion 71 overlap with the second magnetic material 32. In contrast, a portion of the conductor pattern constituting the first circular portion 71 overlaps with the through hole 31a of the first magnetic material 31, and the remaining portion overlaps with the through hole 31a of the first magnetic material 31. The thickness T1 of the first magnetic material 31 and the thickness T2 of the second magnetic material 32 may be approximately the same. In this example, the second magnetic material 32 overlaps with each turn of the first circular portion 71, but it is acceptable if a portion of the outermost turn does not overlap.
[0044] In the example shown in Figure 11(b), the planar size of the second magnetic material 32 is enlarged compared to the example shown in Figure 11(a). As a result, the second magnetic material 32 includes not only the portion that overlaps with the opening region 71a of the first circular portion 71 of the coil pattern CP and the conductor pattern constituting the first circular portion 71, but also the portion that overlaps with the outer region of the first circular portion 71 of the coil pattern CP. Therefore, the second magnetic material 32 includes the portion located outside the outermost turn of the first circular portion 71 of the coil pattern CP.
[0045] In the example shown in Figure 11(c), the planar size of the second magnetic material 32 is reduced compared to the example shown in Figure 11(a). As a result, a portion of the conductor pattern constituting the first circular portion 71 of the coil pattern CP does not overlap with the second magnetic material 32. Furthermore, the size of the second magnetic material 32 may be the same as the size of the through-hole 31a of the first magnetic material 31, or it may be smaller than the size of the through-hole 31a of the first magnetic material 31.
[0046] In the example shown in Figure 11(d), the thickness T2 of the second magnetic material 32 is reduced compared to the example shown in Figure 11(a). As a result, the thickness T2 of the second magnetic material 32 is thinner than the thickness T1 of the first magnetic material 31.
[0047] In any of the structures shown in Figures 11(a) to (d), the inductance of the first circular portion 71 of the coil pattern CP is increased by providing the second magnetic material 32. This makes it possible to suppress the decrease in coupling between the first circular portion 71 of the coil pattern CP and the coupling coil 63 of the IC module 60 due to the influence of the metal plate 40.
[0048] While preferred embodiments of this disclosure have been described above, it goes without saying that this disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of this disclosure, and such modifications are also included within the scope of this disclosure.
[0049] For example, in the above embodiment, the coil conductor is composed of a coil pattern supported by an insulating layer 21, but a coil conductor made by winding a wire may also be used.
[0050] The technology relating to this disclosure includes, but is not limited to, the following configuration examples.
[0051] A coil component according to one embodiment of the present disclosure comprises a first magnetic body having a through hole, a second magnetic body overlapping the through hole of the first magnetic body, and a coil conductor located between the first magnetic body and the second magnetic body, wherein the coil conductor includes a first circular portion, at least a portion of the opening region of the first circular portion of the coil conductor overlaps the through hole of the first magnetic body, and at least a portion of the conductor of the first circular portion of the coil conductor overlaps the second magnetic body. As a result, the inductance of the first circular portion of the coil conductor is increased, making it possible to reduce the influence of eddy currents generated in the metal plate even when a metal plate or the like is placed on the opposite side of the coil conductor from the first magnetic body.
[0052] In the above-described coil component, the coil conductor may further include a second circular portion that circles along the outer edge of the first magnetic material, and a connecting portion that connects the first circular portion and the second circular portion. In this case, the second circular portion of the coil conductor functions as an antenna coil.
[0053] In the above-described coil component, the entire conductor of the first loop of the coil conductor may overlap with the second magnetic material. This makes it possible to further increase the inductance of the first loop of the coil conductor.
[0054] In the above coil component, the second magnetic material may have a portion that overlaps with the first magnetic material. This makes it possible to further increase the inductance of the first circumference of the coil conductor. In this case, a portion of the conductor pattern of the first circumference of the coil conductor may overlap with both the first and second magnetic materials. Even in this case, the inductance of the first circumference of the coil conductor is increased by the overlap of the conductor pattern of the first circumference of the coil conductor with the second magnetic material.
[0055] In the above-described coil component, the second magnetic material may have a portion located outside the outermost turn of the first circumference of the coil conductor. This makes it possible to further increase the inductance of the first circumference of the coil conductor.
[0056] In the above coil component, the second magnetic material may be thinner than the first magnetic material. This makes it possible to reduce the overall thickness of the coil component.
[0057] In the above coil component, the distance between the second magnetic material and the first circumference of the coil conductor may be shorter than the distance between the first magnetic material and the first circumference of the coil conductor. This enhances the inductance improvement effect of the second magnetic material.
[0058] A card according to one embodiment of the present disclosure comprises the above-described coil component. This makes it possible to provide a card with enhanced communication characteristics.
[0059] The above card further comprises a first card substrate made of metal and a second card substrate made of resin, wherein the first card substrate has through holes, the coil component is placed between the first and second card substrates, the first magnetic material faces the first card substrate, the second magnetic material faces the second card substrate, and the through holes of the first card substrate may overlap with the through holes of the first magnetic material. This makes it possible to provide a metal card that can communicate with an external card reader from the second card substrate side.
[0060] The above card may further include an IC module, at least a portion of which is positioned inside a through-hole in the first card substrate. This makes it possible to magnetically couple the IC module with the first circular portion of the coil conductor. [Examples]
[0061] The IC card 2 described using Figures 1 to 5 was actually fabricated, and the communication range with the card reader was measured. The frequency used for communication was 13.56 MHz. There were five types of samples, A to E, and all of them were identical except for the planar size and thickness of the second magnetic material 32.
[0062] Figures 12(a) to (e) are schematic cross-sectional views showing the structure of the coil components in samples A to E, respectively.
[0063] As shown in Figure 12(a), sample A does not have the second magnetic material 32. The thickness of the first magnetic material 31 is 80 μm.
[0064] As shown in Figure 12(b), in sample B, the second magnetic material 32 is positioned only where it overlaps with the opening region 71a of the first circular portion 71 of the coil pattern CP. The second magnetic material 32 does not overlap with the conductor pattern that constitutes the first circular portion 71 of the coil pattern CP. The thickness of the second magnetic material 32 is 80 μm. The other configurations are the same as in sample A.
[0065] As shown in Figure 12(c), in sample C, the second magnetic material 32 overlaps not only with the opening region 71a of the first circular portion 71 of the coil pattern CP, but also with the entire conductor pattern constituting the first circular portion 71 of the coil pattern CP. The other configurations are the same as in sample B.
[0066] As shown in Figure 12(d), in sample D, the size of the second magnetic material 32 is larger than in sample C, and a portion of the second magnetic material 32 overlaps with the first magnetic material 31. The other configurations are the same as in sample C.
[0067] As shown in Figure 12(e), in sample E, the thickness of the second magnetic material 32 has been reduced to 30 μm. The other components are the same as those in sample C.
[0068] The evaluation results are shown in Figure 13. As shown in Figure 13, sample A, which does not have the second magnetic material 32, and sample B, in which the second magnetic material 32 is placed only in a position that overlaps with the opening region 71a of the first circular portion 71 of the coil pattern CP, both had a communication range of 43 mm. In contrast, in samples C to E, in which the second magnetic material 32 overlaps with the conductor pattern constituting the first circular portion 71 of the coil pattern CP, the communication range was expanded to 47 to 48 mm. Sample D had a slightly longer communication range than sample C. Sample E, although the thickness of the second magnetic material 32 was reduced, had the same communication range as sample C. [Explanation of symbols]
[0069] 1,1a Coil component 2,3 IC cards 2a Top of IC card 2b Back of IC card 6 Card Readers 10 Plastic Plates 21-23 Insulating layer 31 First magnetic body 31a Through hole in the first magnetic material 32 Second magnetic body 40 Metal Plates 41 Through holes in metal plates 51,52 Adhesive layer 60 IC modules 61 Module board 62 IC chips 63 Coupling coil 64 Protective resin 71 First lap 71a Opening region of the first circular section 72 Second lap 72a Opening region of the second circular section 73, 74 Connection part 81 Main body 82 Seed section 721 turns CP coil pattern Outer edge of CPa coil pattern CPb coil pattern inner edge S1,S2 surface
Claims
1. A first magnetic material having through holes, A second magnetic material that overlaps with the through hole of the first magnetic material, A coil conductor located between the first magnetic material and the second magnetic material, Equipped with, The coil conductor includes a first circular portion, At least a portion of the opening region of the first peripheral portion of the coil conductor overlaps with the through hole of the first magnetic material, At least a portion of the conductor of the first circular portion of the coil conductor overlaps with the second magnetic material. Coil components.
2. The coil conductor further includes a second circular portion that circles along the outer edge of the first magnetic material, and a connecting portion that connects the first circular portion and the second circular portion. The coil component according to claim 1.
3. The entire conductor of the first circular portion of the coil conductor overlaps with the second magnetic material. The coil component according to claim 1.
4. The second magnetic material has a portion that overlaps with the first magnetic material. The coil component according to claim 1.
5. A portion of the conductor in the first circular portion of the coil conductor overlaps with both the first magnetic material and the second magnetic material. The coil component according to claim 4.
6. The second magnetic material has a portion located outside the outermost turn of the first circular portion of the coil conductor, The coil component according to claim 1.
7. The second magnetic material is thinner than the first magnetic material. The coil component according to claim 1.
8. The distance between the second magnetic material and the first circular portion of the coil conductor is shorter than the distance between the first magnetic material and the first circular portion of the coil conductor. The coil component according to claim 1.
9. A card comprising the coil component described in any one of claims 1 to 8.
10. A first card base material made of metal, A second card base material made of resin, Furthermore, The first card substrate has through holes, The coil component is placed between the first card substrate and the second card substrate. The first magnetic material faces the first card substrate, The second magnetic material faces the second card substrate, The through-holes in the first card substrate overlap with the through-holes in the first magnetic material. The card according to claim 9.
11. The card according to claim 10, further comprising an IC module in which at least a portion is disposed inside the through-hole of the first card substrate.