RFID module and wireless communication device

Abstract

This RFID module comprises: a substrate; an RFIC chip disposed on a first main surface side of the substrate; a first coil conductor disposed on the first main surface side of the substrate; and a first conductor pattern connecting one end of the RFIC chip and one end of the first coil conductor. The first coil conductor has a plurality of coil element bodies each having a first end portion, a second end portion, and a conductor portion extending from the first end portion in an opposite direction from the substrate to form an opening and extending to the second end portion, the coil element bodies being arranged in a line such that the respective openings overlap each other when viewed from a direction orthogonal to opening surfaces; and a second conductor pattern disposed on the first main surface and connected to the coil element bodies to form a coil shape. The other end of the RFIC chip is connected to the other end of the first coil conductor. In the opening, a second width on the opposite side of a first width on the side of the first end portion and the second end portion from the substrate is longer than the first width.

Description

RFID module and wireless communication device

[0001] The present invention relates to an RFID module having a substrate on which a coil conductor is mounted, and a wireless communication device including the same.

[0002] Conventionally, products are managed by attaching an RFID (Radio-Frequency Identification) module to the product. One type of RFID module has an RFIC (Radio-Frequency Integrated Circuit) chip and a coil conductor that functions as an antenna, both of which are disposed on an insulating substrate.

[0003] For example, Patent Document 1 proposes an RFID module having a coil conductor in which coil elements are arranged in a row, and Patent Document 2 proposes an RFID tag (wireless communication device) in which a power supply module (RFID module) is disposed inside a spring coil.

[0004] International Publication No. WO 2018 / 235714 International Publication No. WO 2018 / 101315

[0005] The resonant frequency band can be widened by magnetically coupling the RFID module and spring coil disclosed in Patent Documents 1 and 2. The resonant frequency band can be further widened by widening the coil opening of the RFID module, but this increases the size of the RFID module.

[0006] An object of the present invention is to provide an RFID module and a wireless communication device that can widen the coil opening without increasing the module size.

[0007] An RFID module according to one aspect of the present invention includes a substrate having a first and second principal surfaces facing each other, an RFIC chip disposed on the first principal surface of the substrate, a first coil conductor disposed on the first principal surface of the substrate, and a first conductor pattern connecting one end of the RFIC chip to one end of the first coil conductor. The first coil conductor has a first end, a second end, and a conductor portion extending from the first end in a direction away from the substrate, forming an opening, and extending to the second end. The first coil conductor includes a plurality of coil elements arranged in a row so that a predetermined winding axis passes through the opening, and a second conductor pattern disposed on the first principal surface and connecting to the coil elements to form a coil shape. The other end of the RFIC chip is connected to the other end of the first coil conductor. In the opening, a second width on the side opposite the substrate is longer than a first width on the first and second end sides.

[0008] A wireless communication device according to one aspect of the present invention includes the RFID module described above and a second coil conductor wound around the outer periphery of the RFID module and having an axial length longer than that of the first coil conductor.

[0009] According to the present invention, it is possible to provide an RFID module and a wireless communication device that are capable of widening the coil opening without increasing the module size.

[0010] Graph showing communication characteristics of wireless communication devices of the first embodiment and the comparative example; Front view of a coil element in a first modified example of the first embodiment;

[0011] Each of the embodiments described below shows a specific example of the present invention, and the present invention is not limited to this configuration. Furthermore, the numerical values, shapes, configurations, steps, and step orders specifically shown in the following embodiments are examples and do not limit the present invention. Among the components in the following embodiments, components that are not described in the independent claims that represent the highest concepts are described as optional components. Furthermore, in all embodiments, the configurations in each modification are the same, and the configurations described in each modification may be combined with each other.

[0012] (Embodiment 1) Next, a schematic configuration of an RFID module 1 according to the present invention will be described. FIG. 1 is a perspective view of an RFID module 1 according to an embodiment of the present invention. FIG. 2 is a perspective side view of the RFID module 1 according to the embodiment. In the figures, the X-Y-Z coordinate system is used to facilitate understanding of the invention and does not limit the invention. The X-axis direction indicates the longitudinal direction of the RFID module 1, the Y-axis direction indicates the depth (width) direction, and the Z-axis direction indicates the thickness direction. The X, Y, and Z directions are perpendicular to one another. Furthermore, in the embodiment, the positive direction of the Z axis is the upward direction, and the negative direction of the Z axis is the downward direction.

[0013] The RFID module 1 of the first embodiment includes a laminated substrate 3, a first coil conductor 5 and an RFIC chip 7 disposed on a first main surface 3a, which is the upper surface of the laminated substrate 3, and a resin layer 9 that seals the first coil conductor 5 and the RFIC chip 7. A second main surface 3b, which is the lower surface of the laminated substrate 3, and the first main surface 3a face each other.

[0014] 3, the RFID module 1 can be used as a wireless communication device 100 with a longer wireless communication distance by being placed inside a second coil conductor 10, which is a spring coil. The first coil conductor 5 inside the RFID module 1 and the second coil conductor 10 wound around the outer periphery of the RFID module 1 are magnetically coupled, causing the second coil conductor 10 to function as an antenna.

[0015] Next, reference is made to Figures 4 and 5. Figure 4 is a partially enlarged cross-sectional view of Figure 2, and Figure 5 is a vertical cross-sectional view taken along the arrow V in Figure 1.

[0016] The laminated substrate 3 has a first substrate layer 11, a second substrate layer 13, and a third substrate layer 15, with the third substrate layer 15 serving as the bottom substrate layer, the second substrate layer 13 being stacked on the third substrate layer 15 toward the first coil conductor 5, and the first substrate layer 11 being further stacked on the second substrate layer 13. The first substrate layer 11 to the third substrate layer 15 are each insulating, and are, for example, a glass epoxy substrate or a ceramic substrate.

[0017] The third main surface 11a of the first base layer 11 corresponds to the first main surface 3a of the laminated substrate 3. A fourth main surface 11b on the second main surface 3b side of the first base layer 11 is in contact with a fifth main surface 13a on the first main surface 3a side of the second base layer 13. A sixth main surface 13b on the second main surface 3b side of the second base layer 13 is in contact with a seventh main surface 15a on the first main surface 3a side of the third base layer 15. An eighth main surface 15b, which is the lower surface of the third base layer 15, faces the seventh main surface 15a and corresponds to the second main surface 3b of the laminated substrate 3.

[0018] A first resist layer 16 is laminated on the first main surface 3 a of the laminated substrate 3, and a second resist layer 17 is laminated on the second main surface 3 b of the laminated substrate 3. The first resist layer 16 prevents short-circuiting of electrodes and wiring arranged on the first base layer 11, and the second resist layer 17 covers and protects the lower ends of first interlayer connection conductors 55 and second interlayer connection conductors 57, which will be described later. The first resist layer 16 and the second resist layer are, for example, insulating resin layers.

[0019] The resin layer 9 seals the first coil conductor 5 and the RFIC chip 7, and is laminated on the third main surface 11a of the first base layer 11 and the first resist layer 16. The resin layer 9 is made of a general sealing resin such as epoxy resin. The cross-sectional shape of the RFID module 1 perpendicular to the longitudinal direction is, for example, a rounded rectangle. This shape allows the second coil conductor 10, which has a circular opening, to be closer to the first coil conductor 5 of the RFID module 1.

[0020] Next, reference will be made to Figures 1 and 5 to 7. Figure 6 is a front view of the coil body of the first embodiment, and Figure 7 is a perspective view of the coil body of the first embodiment.

[0021] 1 , the first coil conductor 5 has a plurality of coil elements 21. In the RFID module 1, the first coil conductor 5 is configured to be wound around a winding axis WA by the plurality of coil elements 21 and a second conductor pattern 25 arranged on the third main surface 11 a, which is the upper surface of the first base layer 11, and the first coil conductor 5 functions as an antenna. The number of turns and dimensions of the first coil conductor 5 may be changed according to the communication characteristics.

[0022] 6 and 7, the coil element 21 includes a first end 31, a second end 32, a conductor portion 33, and an opening 34. The coil element 21 is a conductive linear metal block.

[0023] The first end 31 is connected to a first electrode 26 arranged on the laminated substrate 3 via solder 40, and the second end 32 is connected to a second electrode 27 arranged on the laminated substrate 3 via solder 40. The conductor portion 33 extends from the first end 31 in the direction opposite to the laminated substrate 3, forms an opening 34, and extends to the second end 32.

[0024] The conductor portion 33 includes a first bent portion 35 , a first straight portion 36 , a second bent portion 37 , a second straight portion 38 , and a third straight portion 39 .

[0025] First bent portion 35 stands from the inner end of first end portion 31 on the side opposite laminate substrate 3 and extends at an incline outward when viewed from winding axis WA. An inclination angle θ1 of first bent portion 35 with respect to first end portion 31 is 80 degrees or less. An upper end of first bent portion 35 connects to first straight portion 36.

[0026] The first straight portion 36 extends from the inner end of the first end 31 via the first bend 35 in a direction intersecting with the laminated substrate 3. The upper end of the first straight portion 36 bends inward to connect to one end of the third straight portion 39. The outer end of the first end 31 protrudes outward beyond the first straight portion 36, and the outer end of the second end 32 protrudes outward beyond the second straight portion 38. In this way, the outer ends of the first end 31 and the second end 32 each protrude furthest outward in the coil body 21.

[0027] Second bent portion 37 stands from the inner end of second end 32 on the side opposite laminate substrate 3 and extends at an incline outward when viewed from winding axis WA. An inclination angle θ1 of second bent portion 37 with respect to second end 32 is 80 degrees or less. An upper end of second bent portion 37 connects to second straight portion 38.

[0028] The second straight portion 38 extends from the inner end of the second end 32 via the second bend 37 in a direction intersecting with the laminate substrate 3. The upper end of the second straight portion 38 bends inward to connect to the other end of the third straight portion 39. The first straight portion 36 and the second straight portion 38 may extend parallel to each other. The first straight portion 36 is positioned more inward than the outer end of the first end 31, and the second straight portion 38 is positioned more inward than the outer end of the second end 32.

[0029] The third linear portion 39 connects the upper end of the first linear portion 36 and the upper end of the second linear portion 38. The third linear portion 39 may extend parallel to the first main surface 3a of the laminated substrate 3.

[0030] Each coil element 21 is fixed to a first electrode 26 and a second electrode 27, respectively, and the direction perpendicular to the opening surface of each coil element 21 defines a winding axis WA. The openings 34 of each coil element 21 are arranged in a row so as to overlap when viewed perpendicular to the opening surface. When the first coil conductor 5 is mounted on the first base layer 11, each first straight portion 36 of each coil element 21 is arranged on one side of the winding axis WA of the first coil conductor 5, and each second straight portion 38 is arranged on the other side of the winding axis WA. The winding axis WA extends in a direction parallel to the arrangement direction of each coil element 21 (see FIGS. 1 and 6 ). The first end 31 and second end 32 of each coil element 21 serve as connection portions when the coil element 21 is mounted on the first base layer 11.

[0031] In the opening 34 of the coil element 21, the second width W2 on the side opposite to the laminated substrate 3 is longer than the first width W1 on the side of the first end 31 and second end 32. The first width W1 may be the distance between the inner end of the first bent portion 35 and the inner end of the second bent portion 37. The second width W2 is also the width along the third straight portion 39, and it can be said that the width of the opening 34 along the third straight portion 39 is the longest. In this way, the area of ​​the opening 34 can be increased by increasing the opening width on the side away from the laminated substrate 3.

[0032] The coil body 21 has a size in which, for example, the first width W1 is 0.15 mm and the second width W2 is 0.225 mm. The height H1 from the lower ends of the first end portion 31 and the second end portion 32 to the lower end of the third straight portion 39 is 0.30 mm.

[0033] Next, the laminated substrate 3 will be described with reference to Fig. 8. Fig. 8 is a plan view showing each base material of the laminated substrate 3. Fig. 8(a) is a plan view showing the third main surface 11a of the first base material layer 11, the uppermost layer. Fig. 8(b) is a plan view showing the fifth main surface 13a of the second base material layer 13, the middle layer. Fig. 8(c) is a perspective plan view seen through the fifth main surface 13a of the second base material layer 13, the middle layer. Fig. 8(d) is a plan view showing the seventh main surface 15a of the third base material layer 15, the lowermost layer.

[0034] 8( a), on the third main surface 11a, which is the top surface of the first base layer 11, there are arranged first lands 41 and second lands 43 connected to the first terminals 7a and second terminals 7b of the RFIC chip 7, respectively, and a second conductor pattern 25 forming a coil shape by connecting to each of the multiple coil elements 21. The second conductor pattern 25 has a plurality of first electrodes 26, a plurality of second electrodes 27, wiring conductors 28, 29, and 30, and an auxiliary electrode 45.

[0035] The wiring conductor 28 connects the first electrode 26 on one side (the positive side in the Y-axis direction) to the second electrode 27 on the other side (the negative side in the Y-axis direction), which is shifted by one electrode in the positive direction of the X-axis. The first land 41 and the second land 43 are each metal electrodes, and are in contact with and electrically connected to the first terminal 7 a and the second terminal 7 b of the RFIC chip 7, respectively. The first terminal 7 a and the second terminal 7 b of the RFIC chip 7 are each input / output terminals. The second electrode 27 farthest from the first land 41 is electrically connected to the auxiliary electrode 45 via the wiring conductor 29. The first electrode 26 closest to the first land 41 is electrically connected to the second land 43 via the wiring conductor 30.

[0036] 8(b), an electrode 47 is disposed below the first land 41 and the second land 43 on the fifth main surface 13a, which is the upper surface of the second base layer 13. The electrode 47 faces the first land 41 and the second land 43, and capacitance is generated between the electrode 47 and the first land 41 and the second land 43.

[0037] As shown in FIG. 8C, auxiliary electrodes 49 and 51 and a first conductor pattern 53 are arranged on a sixth main surface 13b, which is the lower surface of the second base layer 13.

[0038] In the laminated substrate 3, a first interlayer connection conductor 55 and a second interlayer connection conductor 57 are formed to penetrate the first base material layer 11 and the second base material layer 13, respectively. The first interlayer connection conductor 55 is a conductive via that connects from the first land 41 to the electrode 47 and the auxiliary electrode 49. The second interlayer connection conductor 57 is a conductive via that connects the auxiliary electrode 45 and the auxiliary electrode 51.

[0039] The first and second interlayer connection conductors 55, 57 are, for example, conductors formed by solidifying (metallizing) a conductive paste filled in holes provided in the insulating first base layer 11 and second base layer 13, but may also be plated through holes. The first and second interlayer connection conductors 55, 57 are arranged opposite to each other in the longitudinal direction of the first base layer 11 and second base layer 13, respectively.

[0040] The extension direction of the wiring pattern is folded back at the folded back portion 53b of the first conductor pattern 53. The first conductor pattern 53 is, for example, a meander pattern having straight line patterns 53a extending in the longitudinal direction of the second base layer 13 (the longitudinal direction of the laminate substrate 3) and folded back portions 53b where the extension direction of the straight line patterns 53a is folded back. The first conductor pattern 53 has three or more odd number of straight line patterns 53a and folded back portions 53b, and connects the auxiliary electrode 49 and the auxiliary electrode 51.

[0041] 8( d ), the third base layer 15 is disposed below the second base layer 13. By including the third base layer 15 on which the second main surface 3 b side of the second base layer 13 is laminated in the laminated substrate 3, the first conductor pattern 53 is covered by the third base layer 15, and therefore, it is possible to prevent the first conductor pattern 53 from being rubbed and peeled off. Note that the first interlayer connection conductor 55 and the second interlayer connection conductor 57 reach the seventh main surface 15 a, which is the upper surface of the third base layer 15.

[0042] The first electrode 26, the second electrode 27, the wiring conductors 28, 29, 30, the first land 41, the second land 43, the auxiliary electrode 45, the electrode 47, the auxiliary electrodes 49, 51, and the first conductor pattern 53 are each a conductor, for example, a copper foil patterned by photolithography.

[0043] Next, the effect of widening the resonant frequency band of the RFID module 1 and wireless communication device 100 of embodiment 1 will be described with reference to Fig. 6, Fig. 9, and Fig. 10. Fig. 9 is a front view of a coil body 210 of a comparative example, and Fig. 10 is a graph showing the communication characteristics of the wireless communication device 100 of embodiment 1 and the comparative example.

[0044] In the coil element 210 of the RFID module in the comparative example, a first bent portion 350 rises at approximately 90 degrees from the inner end of the first end 310 and connects to a first straight portion 360. Furthermore, a second bent portion 370 rises at approximately 90 degrees from the inner end of the second end 320 and connects to a second straight portion 380. Therefore, in the opening 340, the first width Wa on the first end 310 and second end 320 side is equal to the second width Wb on the side opposite the laminate substrate 3 from the first width Wa. The first width Wa and the second width Wb are 0.15 mm. The height Ha from the bottom ends of the first end 310 and second end 320 to the bottom end of the third straight portion 390 is 0.30 mm.

[0045] Figure 10 shows graph GH1, which shows the frequency characteristics of the radiation intensity of a wireless communication device 100 equipped with an RFID module 1 including a coil body 21, and graph GH2, which shows the frequency characteristics of the radiation intensity of a wireless communication device equipped with an RFID module including a coil body 210.

[0046] 3, the second coil conductor 10 includes two coil portions: a first coil portion 101 and a second coil portion 102. The second coil portion 102 houses the RFID module 1. The first coil portions 101 extend in the axial direction of the winding axis of the second coil portion 102.

[0047] The spring coil parameters of the wireless communication devices of the first embodiment and the comparative example are the same. The first coil portion 101 of the second coil conductor 10 has a length of 8.0 mm, a diameter of 0.46 mm, a coil pitch of 0.7 mm, and a coil wire diameter of 0.12 mm. The second coil portion 102 of the second coil conductor 10 has a length of 3.0 mm, a diameter of 0.76 mm, a coil pitch of 0.5 mm, and a coil wire diameter of 0.12 mm.

[0048] Furthermore, as size parameters of the RFID module 1, for example, the length of the first coil conductor 5 of the RFID module 1 is 2.4 mm, the coil pitch is 0.16 mm, and the coil cross-sectional dimensions are 0.05 × 0.05 mm. These parameters also have the same specifications as the comparative example. The frequency characteristics of the radiation intensity of the wireless communication device simulated under these conditions are shown in FIG. 10.

[0049] 10, resonance point A1 is the low-frequency side resonance frequency of the wireless communication device 100 including the RFID module 1 of embodiment 1, and resonance point A2 is the low-frequency side resonance frequency of the wireless communication device including the comparative coil body 210. Resonance point B1 is the high-frequency side resonance frequency of the wireless communication device 100 including the RFID module 1, and resonance point B2 is the high-frequency side resonance frequency of the wireless communication device including the comparative coil body 210.

[0050] The resonant frequency band AC1 of the wireless communication device 100 of the first embodiment is about 100 MHz wider than the resonant frequency band AC2 of the wireless communication device using the comparative coil body 210. In this way, by increasing the area of ​​the opening 34 of the coil body 21, the communication frequency bands of the RFID module 1 and the wireless communication device 100 can be widened.

[0051] As described above, the RFID module 1 of embodiment 1 includes a laminated substrate 3 having a first principal surface 3 a and a second principal surface 3 b facing each other, an RFIC chip 7 arranged on the first principal surface 3 a side of the laminated substrate 3, a first coil conductor 5 arranged on the first principal surface 3 a side of the laminated substrate 3, and a first conductor pattern 53 connecting one end of the RFIC chip 7 and one end of the first coil conductor 5.

[0052] The first coil conductor 5 has a first end 31, a second end 32, and a conductor portion 33 extending from the first end 31 in a direction opposite to the laminate substrate 3, forming an opening 34, and extending to the second end 32, and has a plurality of coil bodies 21 arranged in a row so that the openings 34 overlap when viewed from a direction perpendicular to the opening plane, and a second conductor pattern 25 arranged on the first main surface 3a and connecting to the coil bodies 21 to form a coil shape. The other end of the RFIC chip 7 is connected to the other end of the first coil conductor 5, and at the opening 34, a second width W2 on the opposite side to the laminate substrate 3 is longer than a first width W1 on the first end 31 and second end 32 sides.

[0053] According to the RFID module 1 having this configuration, the area of ​​the opening 34 of the coil element 21 when viewed from a direction perpendicular to the opening surface can be increased without increasing the size of the RFID module 1. As a result, for example, when the RFID module 1 is housed inside the second coil conductor 10, the increased area of ​​the opening 34 narrows the coil spacing between the first coil conductor 5 and the second coil conductor 10, thereby increasing the mutual inductance (amount of coupling) between the first coil conductor 5 and the second coil conductor 10. As a result, the frequency interval between the two resonance points can be widened, and the communication frequency band of the wireless communication device 100 can be widened.

[0054] The wireless communication device 100 includes an RFID module 1 and a second coil conductor 10 wound around the outer periphery of the RFID module 1 and having an axial length longer than that of the first coil conductor 5.

[0055] The second coil conductor 10 also functions as an antenna due to magnetic field coupling between the first coil conductor 5 and the second coil conductor 10 of the RFID module 1. The mutual inductance (amount of coupling) between the first coil conductor 5 and the second coil conductor 10 can be increased, thereby widening the communication frequency band of the wireless communication device 100.

[0056] Furthermore, since the first coil conductor 5 has a linear shape, the area of ​​the opening 34 can be made larger within the limited region in the resin layer 9 .

[0057] Next, a first modification of the embodiment will be described with reference to FIG. 11 . FIG. 11 is a front view of a coil body 21A according to the first modification of the first embodiment. The shape of the conductor portion 33A of the coil body 21A according to the first modification is trapezoidal, unlike the shape of the coil body 21A according to the first embodiment. That is, the first straight portion 36A according to the first modification is formed by integrating the first bent portion 35 and the first straight portion 36 according to the first embodiment, and extends linearly after bending from the first end 31. The second straight portion 38A according to the first modification is formed by integrating the second bent portion 37 and the second straight portion 38 according to the first embodiment, and extends linearly after bending from the second end 32. Therefore, the first straight portion 36A and the second straight portion 38A form the oblique side of the trapezoidal shape when viewed from the winding axis WA, and the third straight portion 39 forms the upper side of the trapezoidal shape. The width W2A of the opening 34A along the third straight portion 39 is the longest. Even with this configuration, the same effects as those of the RFID module 1 of the embodiment can be obtained.

[0058] Next, an RFID module 1B according to a second embodiment will be described with reference to Fig. 12 and Fig. 13. Fig. 12 is a perspective view showing an outline of an RFID module 1B according to a second embodiment. Fig. 13 is a vertical cross-sectional view taken along the arrow XIII in Fig. 12.

[0059] The conductor portion 33 of the first coil conductor 5 in embodiment 1 is linear, but the conductor portion 33B of the first coil conductor 5B in embodiment 2 is curved. Except for this point and points described below, the RFID module 1 in embodiment 1 and the RFID module 1B in embodiment 2 are the same in configuration, so a description of the common configuration will be omitted.

[0060] The conductor portion 33B in the second embodiment has a curved shape, which allows it to fit the outer shape of the resin layer 9, which has rounded corners. For example, by making the upper portion of the conductor portion 33B arc-shaped, it can be brought closer to the second coil conductor 10 outside the RFID module 1B. This strengthens the magnetic field coupling between the first coil conductor 5B of the RFID module 1B and the second coil conductor 10, and widens the communication frequency band of the wireless communication device 100B.

[0061] Although the Ω-shaped conductor portion 33B is shown as an example in FIGS. 12 and 13, the shape of the conductor portion 33B is not limited to this, and the lower portion may be linear and the upper portion may be arc-shaped.

[0062] The present invention is not limited to the above-described embodiments, but can be modified as follows.

[0063] In each of the above-described embodiments, the cross-sectional shape of the RFID module 1 perpendicular to the longitudinal direction is, for example, a rounded rectangle with rounded corners, but this is not limited to this. The cross-sectional shape of the RFID module 1 perpendicular to the longitudinal direction may also be a rectangle with corners, or the external shape of the RFID module 1 may be a rectangular parallelepiped. In this case, since the second coil conductor 10 is wound around the rectangular parallelepiped RFID module 1, the coil opening surface may also be a rectangle.

[0064] Although the present invention has been described in various embodiments with a certain degree of detail, the disclosure of these embodiments may vary in structural details, and variations in the combination and order of elements in the various embodiments may be realized without departing from the scope and spirit of the invention as claimed.

[0065] An RFID module according to a first aspect of the present invention includes a substrate having a first and second principal surfaces facing each other, an RFIC chip disposed on the first principal surface of the substrate, a first coil conductor disposed on the first principal surface of the substrate, and a first conductor pattern connecting one end of the RFIC chip to one end of the first coil conductor. The first coil conductor has a first end, a second end, and a conductor portion extending from the first end in a direction away from the substrate, forming an opening, and extending to the second end. The first coil conductor includes a plurality of coil elements arranged in a row so that their openings overlap when viewed perpendicular to the opening plane, and a second conductor pattern disposed on the first principal surface and connected to the coil elements to form a coil shape. The other end of the RFIC chip is connected to the other end of the first coil conductor. In the opening, a second width on the side opposite the substrate relative to the first width is longer than a first width on the first and second end sides.

[0066] In the wireless communication device of this aspect, the second width of the opening of the coil element body on the side opposite the substrate is longer than the first width between the first end and second end of the first coil conductor. Therefore, the area of ​​the opening of the coil element body as viewed from a direction perpendicular to the opening can be increased without increasing the size of the RFID module. As a result, for example, when an RFID module is housed inside the second coil conductor, the increased area of ​​the opening of the coil element body can bring the first coil conductor inside the RFID module closer to the second coil conductor outside the RFID module. This strengthens the magnetic field coupling between the first coil conductor and the second coil conductor, widening the frequency interval between the two resonance points and widening the communication frequency band.

[0067] According to the second aspect, in the RFID module of the first aspect, the conductor portion comprises a first straight portion extending from the first end in a direction intersecting the substrate, a second straight portion extending from the second end in a direction intersecting the substrate, and a third straight portion connecting the first straight portion and the second straight portion.

[0068] According to the third aspect, in the RFID module of the second aspect, the first straight line portion and the second straight line portion form the oblique sides of a trapezoid when viewed from a direction perpendicular to the opening surface, and the third straight line portion forms the upper side of the trapezoid.

[0069] According to a fourth aspect, in the RFID module of the third aspect, the width of the opening is greatest along the third linear portion.

[0070] According to a fifth aspect, in the RFID module of the first aspect, the conductor portion has a curved shape.

[0071] According to a sixth aspect, in the RFID module of the fifth aspect, the conductor portion has an Ω shape when viewed from a direction perpendicular to the opening surface.

[0072] According to a seventh aspect, in an RFID module of any one of the first to sixth aspects, the second conductor pattern has a plurality of first electrodes each connected to a first end of each of the plurality of coil bodies, a plurality of second electrodes each connected to a second end of each of the plurality of coil bodies, and a wiring conductor connecting the second electrodes and the first electrode connected to the first end of an adjacent coil body having a second end connected to the second electrode.

[0073] According to an eighth aspect, in the RFID module of any one of the first to seventh aspects, first and second lands are electrodes arranged on the first main surface side of the substrate, one end of the RFIC chip is connected to the first land, the other end of the RFIC chip is connected to the second land, the first land and one end of the first conductor pattern are connected, and the other end of the first coil conductor is connected to the second land.

[0074] According to a ninth aspect, the RFID module includes the RFID module according to any one of the first to eighth aspects, and a second coil conductor wound around the outer periphery of the RFID module and having an axial length longer than that of the first coil conductor.

[0075] According to this aspect of the wireless communication device, an RFID module having a large opening area of ​​the coil body when viewed from a direction perpendicular to the opening surface is housed in the second coil conductor without increasing the size of the RFID module, thereby strengthening the magnetic field coupling between the first coil conductor and the second coil conductor and widening the communication frequency band.

[0076] REFERENCE SIGNS LIST 1 RFID module 3 Laminated substrate 3a First main surface 3b Second main surface 5 First coil conductor 7 RFIC chip 7a First terminal 7b Second terminal 9 Resin layer 10 Second coil conductor 11 First base material layer 11a Third main surface 11b Fourth main surface 13 Second base material layer 13a Fifth main surface 13b Sixth main surface 15 Third base material layer 15a Seventh main surface 15b Eighth main surface 16 First resist layer 17 Second resist layer 21, 21A Coil element body 25 Second conductor pattern 26 First electrode 27 Second electrode 28, 29, 30 Wiring conductor 31 First end 32 Second end 33 Conductor portion 34 Opening 35 First bent portion 36 First straight portion 37 Second bent portion 38 Second straight portion 39 Third straight portion 40 Solder 41 First land 43 Second land 45 Auxiliary electrode 47 Electrode 49, 51 Auxiliary electrode 53 First conductor pattern 53a Linear pattern 53b Folded portion 55 First interlayer connection conductor 57 Second interlayer connection conductor 100, 100B Wireless communication device 101 First coil portion 102 Second coil portion WA Winding axis

Claims

1. An RFID module comprising: a substrate having first and second principal surfaces opposing each other; an RFIC chip arranged on the first principal surface side of the substrate; a first coil conductor arranged on the first principal surface side of the substrate; and a first conductor pattern connecting one end of the RFIC chip and one end of the first coil conductor, wherein the first coil conductor has: a first end, a second end, and a conductor portion extending from the first end in a direction opposite to the substrate, forming an opening, and extending to the second end, the first coil conductor having a plurality of coil elements arranged in a row so that their openings overlap when viewed from a direction perpendicular to the opening surface; and a second conductor pattern arranged on the first principal surface and connecting to the coil elements to form a coil shape, wherein the other end of the RFIC chip is connected to the other end of the first coil conductor, and at the opening, a second width on the side opposite to the substrate relative to the first width is longer than a first width on the first end and second end sides.

2. The RFID module according to claim 1, wherein the conductor portion comprises: a first straight portion extending from the first end in a direction intersecting the substrate; a second straight portion extending from the second end in a direction intersecting the substrate; and a third straight portion connecting the first straight portion and the second straight portion.

3. The RFID module according to claim 2, wherein the first straight line portion and the second straight line portion form the oblique side of a trapezoid when viewed from a direction perpendicular to the opening surface, and the third straight line portion forms the upper side of the trapezoid.

4. The RFID module according to claim 3, wherein the width of the opening is greatest along the third linear portion.

5. The RFID module according to claim 1, wherein the conductor portion has a curved shape.

6. The RFID module according to claim 5, wherein the conductor portion is Ω-shaped when viewed from a direction perpendicular to the opening surface.

7. An RFID module as described in any one of claims 1 to 6, wherein the second conductor pattern has: a plurality of first electrodes each connected to the first end of each of the plurality of coil bodies; a plurality of second electrodes each connected to the second end of each of the plurality of coil bodies; and a wiring conductor connecting the second electrodes and the first electrode connected to the first end of a coil body adjacent to the coil body having the second end connected to the second electrode.

8. An RFID module according to any one of claims 1 to 7, comprising first and second lands which are electrodes arranged on the first main surface side of the substrate, one end of the RFIC chip connected to the first land and the other end of the RFIC chip connected to the second land, the first land and one end of the first conductor pattern connected, and the other end of the first coil conductor connected to the second land.

9. A wireless communication device comprising: an RFID module according to any one of claims 1 to 8; and a second coil conductor wound around the outer periphery of the RFID module and having an axial length longer than that of the first coil conductor.

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