RFID module

Abstract

This RFID module comprises: a first substrate having a first main surface and a second main surface that face each other; an RFIC chip disposed on the first main surface-side of the first substrate; a first radiation element disposed on the first main surface-side of the first substrate such that at least a part of the radiation element is set apart from the first main surface; and a second radiation element disposed on the second main surface-side of the first substrate. The second radiation element has a first end and a second end that face each other in the longitudinal direction of the first substrate. The first end is electrically connected to one terminal of the RFIC chip. The first radiation element has a third end and a fourth end that face each other in the longitudinal direction of the first substrate. The third end is electrically connected to the other terminal of the RFIC chip. The second end of the second radiation element and the fourth end of the first radiation element are electrically connected to each other. The second radiation element has a first opening.

Description

RFID module

[0001] The present invention relates to an RFID module having a substrate on which an RFIC chip is mounted.

[0002] Conventionally, manufacturing processes of mounting substrates are managed by attaching a radio-frequency identification (RFID) module, which is a wireless communication device, to the substrate. One form of RFID module is one in which an electrode functioning as an antenna is disposed on an insulating substrate together with an RFIC chip (Radio-Frequency Integrated Circuit).

[0003] For example, Patent Document 1 proposes an RFID module that includes a flat electrode as an antenna element.

[0004] International Publication No. 2009-011154

[0005] However, when an RFID module with flat electrodes is used in the manufacturing process of a mounting substrate, for example, during the heating step of the reflow process of the mounting substrate, warping may occur in the substrate due to the difference in thermal expansion coefficient between the substrate in the RFID module and the flat electrodes.If warping occurs in the substrate in the RFID module, communication performance will deteriorate.

[0006] An object of the present invention is to provide an RFID module that can suppress warping of the substrate.

[0007] An RFID module according to one aspect of the present invention includes a first substrate having a first main surface and a second main surface facing each other, an RFIC chip disposed on the first main surface side of the first substrate, a first radiating element disposed on the first main surface side of the first substrate with at least a portion thereof spaced apart from the first main surface, and a second radiating element disposed on the second main surface side of the first substrate. The second radiating element has a first end and a second end opposed to each other in the longitudinal direction of the first substrate. The first end is electrically connected to one terminal of the RFIC chip. The first radiating element has a third end and a fourth end opposed to each other in the longitudinal direction of the first substrate. The third end is electrically connected to the other terminal of the RFIC chip. The second end of the second radiating element and the fourth end of the first radiating element are electrically connected to each other. The second radiating element has a first opening.

[0008] According to the present invention, it is possible to provide an RFID module that can suppress warping of the substrate.

[0009] FIG. 1 is a longitudinal sectional view showing an outline of an RFID module according to a first embodiment; FIG. 2 is a plan view showing electrodes arranged on a substrate of the RFID module according to the first embodiment; FIG. 3 is an explanatory diagram illustrating the positional relationship between a first substrate and a second radiating element in the first embodiment; FIG. 4 is an explanatory diagram illustrating the positional relationship between a substrate and a radiating element in a comparative example; FIG. 5 is a plan view showing electrodes arranged on a substrate of the RFID module according to the second embodiment; FIG. 6 is a longitudinal sectional view showing an outline of an RFID module according to the third embodiment; FIG.

[0010] 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, the configurations in each modification of all embodiments are the same, and the configurations described in each modification may be combined with each other.

[0011] (Embodiment 1) Next, an RFID module 1 according to Embodiment 1 of the present invention will be described. FIG. 1 is a longitudinal cross-sectional view showing an outline of the RFID module 1 of Embodiment 1. FIG. 2 is a plan view showing electrodes arranged on a substrate of the RFID module 1 of Embodiment 1. FIG. 2(a) is a plan view showing the third main surface 5a of the second substrate 5. FIG. 2(b) is a perspective plan view seen through the third main surface 5a of the second substrate 5, showing the fourth main surface 5b side. FIG. 2(c) is a plan view showing the first main surface 3a of the first substrate 3. FIG. 2(d) is a perspective plan view seen through the first main surface 3a of the first substrate 3, showing the second main surface 3b side.

[0012] In the figure, 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 each other. 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 embodiment includes a first substrate 3 , a second substrate 5 , an RFIC chip 7 , and a resin layer 9 .

[0014] The first substrate 3 has a first main surface 3a which is the upper surface and a second main surface 3b which is the lower surface. The first main surface 3a and the second main surface 3b face each other. A first radiating element 13 is arranged on the first main surface 3a side of the first substrate 3, spaced apart from the first main surface 3a, and a second radiating element 11 is arranged on the second main surface 3b. The second radiating element 11 is a metal conductor and has, for example, a first opening 12 in the center of a rectangular pattern.

[0015] The second substrate 5 has a third main surface 5a which is the upper surface, and a fourth main surface 5b which is the lower surface. The third main surface 5a and the fourth main surface 5b face each other. The second substrate 5 is disposed on the first main surface 3a side of the first substrate 3, separated from the first main surface 3a. A first radiating element 13 is disposed on the third main surface 5a of the second substrate 5. The first radiating element 13 is a metal conductor, and has, for example, a second opening 14 in the center of a rectangular pattern. The first substrate 3 and the second substrate 5 are each insulating, and are, for example, a glass epoxy substrate or a ceramic substrate.

[0016] The first radiating element 13 and the second radiating element 11 function as an antenna. The communication frequency band in the RFID module 1 of embodiment 1 is, for example, the UHF band from 860 MHz to 960 MHz. The dimensions of the first radiating element 13 and the second radiating element 11 may be changed according to the communication characteristics.

[0017] The RFIC chip 7 has a first terminal 7a and a second terminal 7b which are input / output terminals. Since the RFIC chip 7 is matched to radio waves of the communication frequency within the RFID module 1, when the first radiating element 13 and the second radiating element 11 receive radio waves of the communication frequency, a current flows through the RFIC chip 7.

[0018] The resin layer 9 seals the RFIC chip 7 and the second substrate 5, and is laminated on the first main surface 3 a of the first substrate 3. The resin layer 9 is made of a general sealing resin such as an epoxy resin.

[0019] A first land 17 and a second land 19 are arranged on the first main surface 3a of the first substrate 3. The first land 17 and the second land 19 are connected to the first terminal 7a and the second terminal 7b of the RFIC chip 7 via solder 15, respectively. Two electrodes 21 are arranged on the longitudinal opposite side of the first land 17, electrically connected to the first radiating element 13 of the second substrate 5. The first substrate 3 internally includes a first interlayer connection conductor 23 that connects the first land 17 and the second radiating element 11, and two second interlayer connection conductors 25 that connect each of the two electrodes 21 and the second radiating element 11. The first interlayer connection conductor 23 and the second interlayer connection conductor 25 are, for example, conductive vias. In FIG. 2 , dashed dotted lines indicate solder connections, and dashed two dotted lines indicate connections by interlayer connection conductors.

[0020] The second land 19 is U-shaped, and one side is connected to the second terminal 7b of the RFIC chip 7, and the other side is electrically connected to the first radiating element 13. An electrode 22 electrically connected to the first radiating element 13 is arranged on the first main surface 3a of the first substrate 3.

[0021] The relationship between the line width of the second radiating element 11 and the width of the first opening 12 will be described with reference to Figures 3 and 4. Figure 3 is an explanatory diagram illustrating the positional relationship between the first substrate 3 and the second radiating element 11. Figure 3(a) shows a perspective plan view of the first substrate 3 and the second radiating element 11. Figure 3(b) shows a side view of the first substrate 3 and the second radiating element 11. Figure 4 is an explanatory diagram illustrating the positional relationship between the first substrate 3 and the radiating element 101 in a comparative example. Figure 4(a) shows a perspective plan view of the first substrate 3 and the radiating element 101. Figure 4(b) shows a side view of the first substrate 3 and the radiating element 101.

[0022] 3, the minimum value of the width Wa of the first opening 12 is larger than the line width Wb of the second radiating element 11. By forming such a first opening 12 in the second radiating element 11, it is possible to suppress warping of the first substrate 3 due to the difference in thermal expansion between the first substrate 3 and the second radiating element 11. The line width Wb of the second radiating element 11 is, for example, 200 μm or more.

[0023] The second radiating element 11 has a first end 11a and a second end 11b extending in the width direction of the first substrate 3, and a side 11c connecting the first end 11a and the second end 11b. The first end 11a, which serves as the first end, is located on the RFIC 7 side, and the second end 11b, which serves as the second end, is located on the side farther from the RFIC 7 (FIG. 2). The line widths of the first end 11a and the second end 11b are greater than that of the side 11c. Because the current flowing through the first end 11a and the second end 11b is greater than the current flowing through the side 11c, this configuration can reduce the resistance value.

[0024] The first end edge 11a is connected to the first inter-layer connecting conductor 23, and the second end edge 11b is connected to the second inter-layer connecting conductor 25. In each drawing, the diameter of each inter-layer connecting conductor is shown exaggerated for clarity, but the line width of the second radiating element 11 is at least twice the diameter of the first inter-layer connecting conductor 23 and the second inter-layer connecting conductor 25. In addition, the area of ​​the first opening 12 is at least half the size of the area surrounded by the outline 11d of the second radiating element 11.

[0025] As shown in Figure 4, when a flat radiating element 101 is arranged on the second main surface 3b of the first substrate 3, warping of the first substrate 3 may occur due to differences in thermal expansion coefficients. The high-frequency current flowing through this radiating element 101 is concentrated along the outer edge of the radiating element 101. The current density is low near the center of the radiating element 101. Therefore, even if the first opening 12 is provided in the center of the second radiating element 11 as shown in Figure 3, the high-frequency current flows concentrated along the second radiating element 11, so there is little impact on communication characteristics.

[0026] 2 , the first radiating element 13 has a third end 13a and a fourth end 13b extending in the width direction of the second substrate 5, and a side 13c connecting the third end 13a and the fourth end 13b. The third end 13a, which serves as the third end, is disposed on the RFIC 7 side, and the fourth end 13b, which serves as the fourth end, is disposed on the side farther from the RFIC 7. The line widths of the third end 13a and the fourth end 13b are greater than that of the side 13c. Because the current flowing through the third end 13a and the fourth end 13b is greater than the current flowing through the side 13c, this configuration can reduce the resistance value.

[0027] A third inter-layer connecting conductor 27 is connected to the third end edge 13a, and a fourth inter-layer connecting conductor 29 is connected to the fourth end edge 13b. The third inter-layer connecting conductor 27 and the fourth inter-layer connecting conductor 29 are, for example, conductive vias. The line width of the first radiating element 13 is at least twice the diameter of the third inter-layer connecting conductor 27 and the fourth inter-layer connecting conductor 29. The area of ​​the second opening 14 is at least 50% of the area surrounded by the outline 13d of the first radiating element 13. As with the second radiating element 11, even if the second opening 14 is provided in the center of the first radiating element 13, the high-frequency current flows concentratedly along the first radiating element 13, so there is little effect on communication characteristics.

[0028] The second substrate 5 has arranged thereon an electrode 31 connected to the third end edge 13a of the first radiating element 13 via a third inter-layer connecting conductor 27, and an electrode 33 connected to the fourth end edge 13b via a fourth inter-layer connecting conductor 29. The second substrate 5 has two third inter-layer connecting conductors 27 and two fourth inter-layer connecting conductors 29 inside. One electrode 31 is connected to the electrode 22 of the first substrate 3 via solder 15, and the other electrode 31 is connected to the second land 19 of the first substrate 3 via solder 15. The two electrodes 33 are each connected to the two electrodes 21 of the first substrate 3 via solder 15.

[0029] Furthermore, by configuring the second radiating element 11 so that its line width is larger than that of the first radiating element 13, or by configuring the first radiating element 13 so that its line width is larger than that of the second radiating element 11, the second radiating element 11 and the first radiating element 13 can be arranged to overlap in a plan view, thereby preventing deterioration of communication characteristics.

[0030] The first to fourth interlayer connection conductors 23, 25, 27, and 29 are, for example, conductors formed by solidifying (metallizing) a conductive paste filled in holes provided in the insulating first substrate 3 or second substrate 5, but may also be plated through holes.

[0031] The second radiating element 11, the first radiating element 13, the first land 17, the second land 19, and the electrodes 21, 22, 31, and 33 are each a conductor, and are formed by patterning copper foil by photolithography, for example.

[0032] With this configuration, high frequency current flows from the second terminal 7b of the RFIC chip through the first radiating element 13 and the second radiating element 11 to the first terminal 7a.

[0033] As described above, the RFID module 1 of the first embodiment includes the first substrate 3 having the first and second main surfaces 3a and 3b facing each other, the RFIC chip 7 disposed on the first main surface 3a side of the first substrate 3, the first radiating element 13 disposed on the first main surface 3a side of the first substrate 3 and spaced apart from the first main surface 3a, and the second radiating element 11 disposed on the second main surface 3b side of the first substrate 3. The second radiating element 11 has a first end edge 11a and a second end edge 11b that face each other in the longitudinal direction of the first substrate 3. The first end edge 11a is electrically connected to one of the first terminals 7a of the RFIC chip 7. The first radiating element 13 has a third end edge 13a and a fourth end edge 13b that face each other in the longitudinal direction of the first substrate 3. The third end edge 13a is electrically connected to the other of the second terminals 7b of the RFIC chip 7. The second end side 11 b of the second radiating element 11 and the fourth end side 13 b of the first radiating element 13 are electrically connected to each other, and the second radiating element 11 has a first opening 12 .

[0034] In the RFID module 1 having this configuration, the second radiating element 11 arranged on the second main surface 3b side of the first substrate 3 has a first opening 12, and the minimum value of the width Wa of the first opening 12 is greater than the line width Wb of the second radiating element 11. Because the contact area of ​​the second radiating element 11 is reduced, the force applied to the interface between the second radiating element 11 and the first substrate 3 when heated is reduced. This makes it possible to prevent warping of the first substrate 3 even if the second radiating element 11 thermally expands.

[0035] The RFID module 1 also includes a second substrate 5 having a third main surface 5a and a fourth main surface 5b facing each other, and arranged so that the first main surface 3a and the fourth main surface 5b of the first substrate 3 face each other. The RFIC chip 7 is arranged adjacent to the second substrate 5, and the first radiating element 13 is arranged on the third main surface 5a side of the second substrate 5, and the first radiating element 13 has a second opening 14. The minimum width Wd of the second opening 14 is larger than the line width We of the first radiating element 13.

[0036] According to this configuration, the first radiating element 13 arranged on the third main surface 5a side of the second substrate 5 has the second opening 14, and the minimum width Wd of the second opening 14 is larger than the line width We of the first radiating element 13, so that the ground contact area of ​​the first radiating element 13 is reduced even if the second substrate 5 thermally expands, thereby preventing warping of the second substrate 5. Furthermore, by mounting the RFIC chip 7 and the second substrate 5 on the same side of the first substrate 3, the height of the RFIC chip 7 can be reduced compared to when they are arranged on both sides.

[0037] (Embodiment 2) Next, an RFID module 1A according to embodiment 2 will be described with reference to FIGS. 5 and 6. FIG. 5 is a schematic longitudinal cross-sectional view of the RFID module 1A according to embodiment 2, taken along line A-A in FIG. 6. FIG. 6 is a plan view showing electrodes arranged on the substrates of the RFID module 1A according to embodiment 2. FIG. 6(a) is a plan view showing the third main surface 5a of the second substrate 5 and the fifth main surface 41a of the third substrate 41. FIG. 6(b) is a perspective plan view seen through the third main surface 5a of the second substrate 5, showing the fourth main surface 5b side. FIG. 6(c) is a plan view showing the first main surface 3a of the first substrate 3. FIG. 6(d) is a perspective plan view seen through the first main surface 3a of the first substrate 3, showing the second main surface 3b side.

[0038] The first radiating element 13A in the second embodiment is divided and arranged on the second substrate 5A and the third substrate 41, and the second substrate 5 in the first embodiment is divided into two substrates. Except for this point and points described below, the RFID module 1A in the second embodiment and the RFID module 1 in the first embodiment are the same in configuration, and therefore a description of the common configuration will be omitted.

[0039] The third substrate 41 has a fifth main surface 41 a that is the upper surface and a sixth main surface 41 b that is the lower surface. The third substrate 41 is disposed so that the sixth main surface 41 b faces the first main surface 3 a of the first substrate 3, and is disposed on the opposite side of the RFIC chip 7 with respect to the second substrate 5A.

[0040] The first radiating element 13A has a first conductor 13Aa arranged on the third principal surface 5a of the second substrate 5A, a second conductor 13Ab arranged on the fifth principal surface 41a side of the third substrate 41, and a third conductor 13Ac arranged on the first principal surface 3a side of the first substrate 3. The first conductor 13Aa and the second conductor 13Ab each have a concave or U-shape, and a third end edge 13a of the first conductor 13Aa and a fourth end edge 13b of the second conductor 13Ab each correspond to the bottom of the concave shape. The first conductor 13Aa and the second conductor 13Ab have second openings 14 that form recesses, and the first conductors 13Aa and the second conductors 13Ab are arranged so that their second openings 14 face each other.

[0041] Two electrodes 31 and two electrodes 35 are arranged on the fourth main surface 5b of the second substrate 5A. The two electrodes 31 and the first conductor 13Aa are connected by a third interlayer connection conductor 27. Two tip portions of the first conductor 13Aa and the two electrodes 35 are connected via two fifth interlayer connection conductors 36, respectively.

[0042] Two electrodes 33 and two electrodes 37 are arranged on the sixth main surface 41b of the third substrate 41. The two electrodes 33 and the second conductor 13Ab are connected by a fourth interlayer connection conductor 29. Two tip portions of the second conductor 13Ab are connected to the two electrodes 37 via two sixth interlayer connection conductors 38, respectively.

[0043] Two third conductors 13Ac extending in the longitudinal direction are arranged in the center of the first main surface 3a of the first substrate 3. One of the third conductors 13Ac is connected to an electrode 35 by solder 15. The other of the third conductors 13Ac is connected to an electrode 37 by solder 15. In this way, the first radiating element 13A is configured across the three substrates.

[0044] Furthermore, the second radiating element 11 has a third opening 11e at a location where it overlaps with the third conductor 13Ac across the first substrate 3. Because the second radiating element 11 and the third conductor 13Ac are at different potentials, capacitance occurs at the location where the second radiating element 11 and the third conductor 13Ac overlap in a planar view. Therefore, by forming the third opening 11e at the location where the second radiating element 11 overlaps with the third conductor 13Ac in a planar view, the generation of capacitance is suppressed, and degradation of communication characteristics is suppressed.

[0045] As described above, the RFID module 1A of the second embodiment includes the second substrate 5A having the third main surface 5a and the fourth main surface 5b facing each other and disposed so that the first main surface 3a and the fourth main surface 5b of the first substrate 3 face each other, and the third substrate 41 having the fifth main surface 41a and the sixth main surface 41b facing each other and disposed so that the first main surface 3a and the sixth main surface 41b of the first substrate 3 face each other. The RFIC chip 7 is disposed adjacent to the second substrate 5A, and the third substrate 41 is disposed on the opposite side of the RFIC chip 7 with respect to the second substrate 5A. The first radiating element 13A includes a first conductor 13Aa disposed on the third main surface 5a of the second substrate 5A, a second conductor 13Ab disposed on the fifth main surface 41a side of the third substrate 41, and a third conductor 13Ac disposed on the first main surface 3a side of the first substrate 3. The first conductor 13Aa, the second conductor 13Ab, and the third conductor 13Ac are electrically connected, and the first radiating element 13A has a second opening 14. The minimum width of the second opening 14 is larger than the line width of the first radiating element 13A.

[0046] Since the substrate facing the first substrate 3 is divided into two, the second substrate 5A and the third substrate 41, the longitudinal length of the substrate facing the first substrate 3 can be shortened, thereby further suppressing the occurrence of warping.

[0047] (Embodiment 3) Next, an RFID module 1B according to embodiment 3 will be described with reference to FIGS. 7 and 8. FIG. 7 is a schematic longitudinal cross-sectional view of the RFID module 1B according to embodiment 3, taken along line B-B in FIG. 8. FIG. 8 is a plan view showing electrodes arranged on the substrates of the RFID module 1B according to embodiment 3. FIG. 8(a) is a plan view showing the third main surface 5a of the second substrate 5 and the fifth main surface 41a of the third substrate 41. FIG. 8(b) is a perspective plan view seen through the third main surface 5a of the second substrate 5, showing the fourth main surface 5b side. FIG. 8(c) is a plan view showing the first main surface 3a of the first substrate 3. FIG. 8(d) is a perspective plan view seen through the first main surface 3a of the first substrate 3, showing the second main surface 3b side.

[0048] In the first radiating element 13B in the third embodiment, the second wiring pattern 13ba extends from the fourth end side 43b of the second conductor 13Aba arranged on the fifth main surface 41a of the third substrate 41 in the second embodiment in a direction away from the RFIC 9. Other than this point and points described below, the configuration of the RFID module 1B in the third embodiment is the same as that of the RFID module 1A in the second embodiment, and therefore a description of the common configuration will be omitted.

[0049] The second conductor 13Aba has a concave first wiring pattern 13f, and a second wiring pattern 13ba extends from the bottom of the first wiring pattern 13f in a direction away from the RFIC 9. The second wiring pattern 13ba has, for example, an L-shape. Only one fourth interlayer connection conductor 29 is arranged at the tip of the second wiring pattern 13ba. The current is largest at the short-circuit point between the first radiating element 13B and the electrode 21 and second interlayer connection conductor 25 of the first substrate 3, but the second wiring pattern 13ba can increase the L component, thereby efficiently lowering the resonant frequency.

[0050] As described above, in the RFID module 1B of embodiment 3, the second conductor 13Aba has a concave-shaped first wiring pattern 13f and a second wiring pattern 13ba extending from the first wiring pattern 13f in a direction away from the RFIC chip 7, and the fourth end is the end of the second wiring pattern 13ba.

[0051] As a result, by arranging the second wiring pattern 13ba that increases the L component in the location where the most current flows, the resonance frequency can be efficiently lowered.

[0052] (Fourth Embodiment) Next, an RFID module 1C according to a fourth embodiment will be described with reference to FIGS. 9 and 10. FIG. 9 is a schematic longitudinal cross-sectional view of the RFID module 1C according to the fourth embodiment, taken along line CC in FIG. 10. FIG. 10 is a plan view showing electrodes arranged on the substrates of the RFID module 1C according to the fourth embodiment. FIG. 10(a) is a plan view showing the third main surface 5a of the second substrate 5 and the fifth main surface 41a of the third substrate 41. FIG. 10(b) is a perspective plan view seen through the third main surface 5a of the second substrate 5, showing the fourth main surface 5b side. FIG. 10(c) is a plan view showing the first main surface 3a of the first substrate 3. FIG. 10(d) is a perspective plan view seen through the first main surface 3a of the first substrate 3, showing the second main surface 3b side.

[0053] The first radiating element 13C in the fourth embodiment has a configuration in which the second wiring pattern 13ba, which is arranged on the fifth main surface 41a of the third substrate 41 in the third embodiment, is arranged on the first main surface 3a side of the first substrate 3. Other than this point and points described below, the RFID module 1C in the fourth embodiment and the RFID module 1A in the second embodiment are the same in configuration, and therefore a description of the common configuration will be omitted.

[0054] One of the two electrodes 21 of the first substrate 3 has a third wiring pattern 13bb extending from the electrode 21 in a direction away from the RFIC chip 7. As a result, the current becomes largest at the short-circuit point between the first radiating element 13C and the electrode 21 of the first substrate 3 and the second interlayer connecting conductor 25, but the third wiring pattern 13bb can increase the L component, thereby efficiently lowering the resonant frequency. The third wiring pattern 13bb may be, for example, meander-shaped or L-shaped.

[0055] As described above, in the RFID module 1C of the fourth embodiment, the third wiring pattern 13bb, which is electrically connected to the fourth end side 13b of the second conductor 13Ab on the side farther from the RFIC chip 7, is disposed on the first main surface 3a side of the first substrate 3. The third wiring pattern 13bb extends in a direction away from the RFIC chip 7, and an end of the third wiring pattern 13bb and the second end side 11b of the second radiating element 11 are electrically connected.

[0056] As a result, by arranging the second wiring pattern 13ba that increases the L component in the location where the most current flows, the resonance frequency can be efficiently lowered.

[0057] Fifth Embodiment Next, an RFID module 1D according to a fifth embodiment will be described with reference to FIGS. 11 and 12. FIG. 11 is a schematic longitudinal cross-sectional view of the RFID module 1D according to the fifth embodiment, taken along line D-D in FIG. 12. FIG. 11 is a plan view showing electrodes arranged on the substrates of the RFID module 1D according to the fifth embodiment. FIG. 12(a) is a plan view showing the third main surface 5a of the second substrate 5 and the fifth main surface 41a of the third substrate 41. FIG. 12(b) is a perspective plan view seen through the third main surface 5a of the second substrate 5, showing the fourth main surface 5b side. FIG. 12(c) is a plan view showing the first main surface 3a of the first substrate 3. FIG. 12(d) is a perspective plan view seen through the first main surface 3a of the first substrate 3, showing the second main surface 3b side.

[0058] The first radiating element 13D in the fifth embodiment is configured such that the third wiring pattern 13bb arranged on the first main surface 3a of the first substrate 3 in the fourth embodiment is arranged, in a plan view, inside the second conductor 13Aba formed on the fifth main surface 41a of the third substrate 41. Other than this point and points described below, the RFID module 1D in the fifth embodiment and the RFID module 1C in the fourth embodiment are the same in configuration, and therefore a description of the common configuration will be omitted.

[0059] In the RFID module 1D of the fifth embodiment, the third conductor 13Ac has an electrode pattern 51 that electrically connects the first conductor 13Aa and the second conductor 13Aba, and a third wiring pattern 13bb that is electrically connected to the side of the second conductor 13Aba farther from the RFIC chip 7 and extends in a direction away from the RFIC chip 7. The third wiring pattern 13bb is arranged so that at least a portion of it overlaps with the second opening 14 in a plan view. An electrode 39 provided at an end of the sixth main surface 41b of the third substrate 41 farther from the RFIC chip 7 is connected via solder 15 to an electrode 30 provided at an end of the first main surface 3a of the first substrate 3 farther from the RFIC chip 7.

[0060] Since the second opening 14 and the third wiring pattern 13bb overlap in a planar view, it is possible to extend the wiring pattern to the end of the first substrate while preventing a decrease in the inductance value, thereby improving the antenna characteristics of the RFID module 1D.

[0061] Sixth Embodiment Next, an RFID module 1E according to a sixth embodiment will be described with reference to Fig. 13 and Fig. 14. Fig. 13 is a longitudinal cross-sectional view showing an outline of the RFID module 1E according to the sixth embodiment. Fig. 14 is a plan view of the first conductors 13Ea and the second conductors Eb of the RFID module 1E according to the sixth embodiment.

[0062] The first conductor 13Ea and the second conductor Eb of the RFID module 1E in the sixth embodiment are made of sheet metal, and the RFID module 1E does not include a second substrate or a third substrate. Except for this point and points described below, the RFID module 1E in the sixth embodiment and the RFID module 1A in the second embodiment are the same in configuration, and therefore a description of the common configuration will be omitted.

[0063] The first conductor 13Ea and the second conductor 13Eb have the same structure, and each has a rectangular first frame 61, a second frame 63 connected to divide the first frame 61 into two, an opening 64 surrounded by the first frame 61 and the second frame 63, and legs 65 extending from the four corners of the first frame toward the first substrate 3.

[0064] Since the second frame 63 is disposed near the longitudinal center of the first frame 61, the second frame 63 can function as a mounting machine suction portion when mounting the first conductors 13Ea and the second conductors 13Eb. Furthermore, when the first conductors 13Ea and the second conductors 13Eb are thin, the second frame 63 can suppress warping during sheet metal formation.

[0065] The first conductor 13Ea and the second conductor 13Eb, which are made of sheet metal, have leg portions 65 formed by crushing, harp punching, or bending. A manufacturing method for the first conductor 13Ea and the second conductor 13Eb will be described with reference to Figures 15 to 17. Here, a manufacturing method using bending will be described. Figures 15 and 16 are process diagrams for forming the first conductor 13Ea and the second conductor 13Eb, and Figure 17 is a side view taken along line E-E in Figure 16.

[0066] 15, the plate-shaped first frame 61 and leg portions 65 can be formed by stamping out a single sheet of metal. Next, as shown in FIGS. 16 and 17, the leg portions 65 are bent 90 degrees relative to the first frame 61 to form the first conductors 13Ea and second conductors 13Eb.

[0067] As described above, in the RFID module 1E of the sixth embodiment, the first radiating element 13E has the first conductor 13Ea and the second conductor 13Eb, which are metal plates, and the third conductor 13Ac, which is disposed on the first main surface 3a side of the first substrate 3. The first conductor 13Ea is disposed adjacent to the RFIC chip 7, and the second conductor 13Eb is disposed on the opposite side of the RFIC chip 7 with respect to the first conductor 13Ea. The first conductor 13Ea, the second conductor 13Eb, and the third conductor 13Ac are electrically connected to each other.

[0068] With these configurations, the first conductor 13Ea and the second conductor 13Eb on the RFIC chip 7 side from the first substrate 3 are made of sheet metal only, and since there is no substrate, warping can be prevented.

[0069] Seventh Embodiment Next, an RFID module 1F according to a seventh embodiment will be described with reference to Fig. 18 and Fig. 19. Fig. 18 is a longitudinal cross-sectional view showing an outline of an RFID module 1F according to the seventh embodiment. Fig. 19 is a plan view of a first conductor 13Fa and a second conductor Fb of the RFID module 1F according to the seventh embodiment.

[0070] The first conductor 13Fa and the second conductor Fb of the RFID module 1F in the seventh embodiment have a concave shape instead of a rectangular shape. Except for this point and points described below, the RFID module 1F in the seventh embodiment and the RFID module 1E in the sixth embodiment have the same configuration, and therefore a description of the common configuration will be omitted.

[0071] The first conductor 13Fa and the second conductor 13Fb have the same structure and each have a concave-shaped third frame 71. The third frame 71 has two side edges 71a and one bottom edge 71b. The first conductor 13Fa and the second conductor 13Fb further have a fourth frame 73 connecting each other at the center of the two side edges 71a, openings 74 and 75 surrounded by the third frame 71 and the fourth frame 73, and legs 65 extending from the four corners of the third frame 71 toward the first substrate 3. The opening 75 is a recess formed by the third frame 71 and the fourth frame 73.

[0072] Since the fourth frame 73 is disposed near the longitudinal center of the third frame 71, the fourth frame 73 can function as a mounting machine suction portion when mounting the first conductors 13Fa and the second conductors 13Fb. Furthermore, when the first conductors 13Fa and the second conductors 13Fb are thin, the fourth frame 73 can suppress warping during sheet metal formation.

[0073] As described above, in the RFID module 1F of the seventh embodiment, the first conductor 13Fa and the second conductor 13Fb have a concave third frame 71 having two side edges 71a and one bottom edge 71b, and a fourth frame 73 connecting the two side edges 71a at the center. The fourth frames 73 of the first conductor 13Fa and the second conductor 13Fb are arranged to face each other.

[0074] With these configurations, compared to the first conductor 13Ea and the second conductor 13Eb of embodiment 6, the opposing sides of the metal plate are removed leaving the leg portions 65, thereby improving the resin fluidity during resin molding of the resin layer 9.

[0075] The present invention is not limited to the above-described embodiments, but can be modified as follows.

[0076] In the fourth and fifth embodiments, the first conductor and the second conductor are disposed on the second and third substrates, respectively, but this is not limiting. As in the sixth and seventh embodiments, the first conductor and the second conductor may be formed of sheet metal without using the second and third substrates.

[0077] 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.

[0078] (Summary of the Embodiments) An RFID module according to a first aspect of the present invention includes a first substrate having a first main surface and a second main surface facing each other, an RFIC chip arranged on the first main surface side of the first substrate, a first radiating element arranged on the first main surface side of the first substrate with at least a portion thereof spaced apart from the first main surface, and a second radiating element arranged on the second main surface side of the first substrate. The second radiating element has a first end and a second end facing each other in the longitudinal direction of the first substrate. The first end is electrically connected to one terminal of the RFIC chip. The first radiating element has a third end and a fourth end facing each other in the longitudinal direction of the first substrate. The third end is electrically connected to the other terminal of the RFIC chip. The second end of the second radiating element and the fourth end of the first radiating element are electrically connected to each other. The second radiating element has a first opening.

[0079] In the RFID module of this aspect, the second radiating element disposed on the second main surface side of the first substrate has the first opening, and therefore the contact area of ​​the second radiating element with the first substrate is reduced, thereby reducing the force applied to the interface between the second radiating element and the first substrate when heated, thereby preventing warping of the first substrate even if the second radiating element thermally expands.

[0080] According to a second aspect, in the RFID module of the first aspect, the minimum width of the first opening is greater than the line width of the second radiating element.

[0081] According to a third aspect, in the RFID module of the first or second aspect, the area of ​​the first opening is equal to or greater than half the area of ​​the region surrounded by the outline of the second radiating element.

[0082] According to a fourth aspect, in an RFID module according to any one of the first to third aspects, the first substrate has an interlayer connecting conductor that electrically connects one terminal of the RFIC chip to the first end, and the line width of the second radiating element is at least twice the diameter of the interlayer connecting conductor.

[0083] According to a fifth aspect, in the RFID module of any one of the first to fourth aspects, there is provided a second substrate having a third main surface and a fourth main surface opposing each other and arranged so that the first main surface and the fourth main surface of the first substrate face each other, the RFIC chip is arranged adjacent to the second substrate, the first radiating element is arranged on the third main surface side of the second substrate, the first radiating element has a second opening, and the minimum width of the second opening is larger than the line width of the first radiating element.

[0084] According to a sixth aspect, in the RFID module of any one of the first to fifth aspects, one of the first and second radiating elements has a line width greater than the line width of the other.

[0085] According to a seventh aspect, the RFID module of any one of the first to fourth aspects includes: a second substrate having a third main surface and a fourth main surface opposing each other and disposed so that the first main surface and the fourth main surface of the first substrate face each other; and a third substrate having a fifth main surface and a sixth main surface opposing each other and disposed so that the first main surface and the sixth main surface of the first substrate face each other. The RFIC chip is disposed adjacent to the second substrate, and the third substrate is disposed on the opposite side of the RFIC chip with respect to the second substrate. The second radiating element has a first conductor disposed on the third main surface of the second substrate, a second conductor disposed on the fifth main surface side of the third substrate, and a third conductor disposed on the first main surface side of the first substrate. The first conductor, the second conductor, and the third conductor are electrically connected. The first radiating element has a second opening, and the minimum width of the second opening is greater than the line width of the first radiating element.

[0086] According to an eighth aspect, in the RFID module of the seventh aspect, the second radiating element has a third opening at a location where the second radiating element overlaps with the third conductor with the first substrate sandwiched therebetween.

[0087] According to a ninth aspect, in the RFID module of the seventh or eighth aspect, the second conductor has a concave-shaped first wiring pattern and a second wiring pattern extending from the first wiring pattern in a direction away from the RFIC chip, and the fourth end is an end of the second wiring pattern.

[0088] According to a tenth aspect, in the RFID module of the seventh or eighth aspect, a third wiring pattern electrically connected to the side of the second conductor farther from the RFIC chip is arranged on the first main surface side of the first substrate, the third wiring pattern extending in a direction away from the RFIC chip, and an end of the third wiring pattern electrically connected to the second end of the second radiating element.

[0089] According to an eleventh aspect, in the RFID module of the seventh or eighth aspect, the third conductor has a third wiring pattern that electrically connects the first conductor and the second conductor, and a fourth wiring pattern that is electrically connected to the side of the second conductor farther from the RFIC chip and extends in a direction away from the RFIC chip, and at least a portion of the third wiring pattern is arranged to overlap with the second opening in a plan view.

[0090] According to a twelfth aspect, in the RFID module of any one of the first to fourth aspects, the first radiating element has a first conductor and a second conductor that are metal plates, and a third conductor that is arranged on the first main surface side of the first substrate. The first conductor is arranged adjacent to the RFIC chip, and the second conductor is arranged on the opposite side of the RFIC chip with respect to the first conductor. The first conductor, the second conductor, and the third conductor are electrically connected.

[0091] According to a thirteenth aspect, in the RFID module of the twelfth aspect, the first conductor and the second conductor have a rectangular first frame and a second frame connected to divide the first frame into two.

[0092] According to a fourteenth aspect, in the RFID module of the twelfth or thirteenth aspect, the first conductor and the second conductor each have two side edges and one bottom edge, and include a concave third frame and a fourth frame connecting the two side edges at the center, and the fourth frames of the first conductor and the second conductor are arranged to face each other.

[0093] 1, 1A, 1B, 1C, 1D, 1F RFID module 3 First substrate 3a First main surface 3b Second main surface 5, 5A Second substrate 5a Third main surface 5b Fourth main surface 7 RFIC chip 7a First terminal 7b Second terminal 9 Resin layer 11 Second radiating element 11a First edge 11b Second edge 11c Side edge 11d Outline 11e Third opening 12 First opening 13, 13A First radiating element 13a Third edge 13b Fourth edge 13ba Second wiring pattern 13bb Third wiring pattern 13c Side edge 13d Outline 13f First wiring pattern 13Aa, 13Ea First conductor 13Ab, 13Aba, 13Eb Second conductor 13Ac Third conductor 14 Second opening 15 Solder 17 First land 19 Second land 21, 22 Electrodes 23 First interlayer connection conductor 25 Second interlayer connection conductor 27 Third interlayer connection conductor 29 Fourth interlayer connection conductor 30, 31, 33, 35 Electrodes 36 Fifth interlayer connection conductor 37 Electrode 38 Sixth interlayer connection conductor 39 Electrode 41 Third substrate 41a Fifth main surface 41b Sixth main surface 61 First frame 63 Second frame 64 Opening 65 Leg 71 Third frame 71a Side edge 71b Bottom edge 73 Fourth frame Wa Width Wb Line width

Claims

1. A first substrate having a first main surface and a second main surface opposed to each other; An RFIC chip disposed on the first main surface side of the first substrate; A first radiating element is disposed on a first main surface side of the first substrate, and at least a portion of the first radiating element is spaced apart from the first main surface; a second radiating element disposed on a second main surface side of the first substrate; the second radiating element has a first end and a second end opposed to each other in a longitudinal direction of the first substrate, the first end is electrically connected to one terminal of the RFIC chip; the first radiating element has a third end and a fourth end opposed to each other in a longitudinal direction of the first substrate; the third end is electrically connected to the other terminal of the RFIC chip; the second end of the second radiating element and the fourth end of the first radiating element are electrically connected to each other; The second radiating element has a first opening in a central portion of a closed pattern of the second radiating element. RFID module.

2. The minimum width of the first opening is greater than the line width of the second radiating element. The RFID module according to claim 1 .

3. The area of ​​the first opening is equal to or larger than half the area of ​​a region surrounded by an outline of the second radiating element. The RFID module according to claim 1 .

4. the first substrate includes an interlayer connection conductor that electrically connects one terminal of the RFIC chip and the first end portion; The line width of the second radiating element is at least twice the diameter of the interlayer connection conductor. The RFID module according to claim 1 .

5. a second substrate having a third main surface and a fourth main surface opposed to each other, the second substrate being disposed such that the first main surface and the fourth main surface of the first substrate are opposed to each other; The RFIC chip is disposed adjacent to the second substrate, the first radiating element is disposed on a third main surface side of the second substrate, the first radiating element has a second aperture; The minimum width of the second opening is greater than the line width of the first radiating element. The RFID module according to claim 1 .

6. The line width of one of the first radiating element and the second radiating element is larger than the line width of the other of the first radiating element and the second radiating element. The RFID module according to claim 1 .

7. a second substrate having a third main surface and a fourth main surface opposed to each other, the second substrate being disposed such that the first main surface and the fourth main surface of the first substrate are opposed to each other; a third substrate having a fifth main surface and a sixth main surface opposed to each other, the third substrate being disposed such that the first main surface of the first substrate faces the sixth main surface; The RFIC chip is disposed adjacent to the second substrate, the third substrate is disposed on an opposite side of the RFIC chip with respect to the second substrate; the first radiating element includes a first conductor arranged on a third main surface of the second substrate, a second conductor arranged on a fifth main surface side of the third substrate, and a third conductor arranged on a first main surface side of the first substrate; the first conductor, the second conductor, and the third conductor are electrically connected; the first radiating element has a second aperture; The minimum width of the second opening is greater than the line width of the first radiating element. The RFID module according to claim 1 .

8. The second radiating element has a third opening at a location where the second radiating element overlaps with the third conductor across the first substrate. The RFID module according to claim 7.

9. the second conductor has a first wiring pattern having a concave shape and a second wiring pattern extending from the first wiring pattern in a direction away from the RFIC chip; the fourth end portion is an end portion of the second wiring pattern; The RFID module according to claim 7.

10. a third wiring pattern electrically connected to a side of the second conductor farther from the RFIC chip, the third wiring pattern being disposed on the first main surface side of the first substrate; the third wiring pattern extends in a direction away from the RFIC chip, an end of the third wiring pattern and the second end of the second radiating element are electrically connected to each other; The RFID module according to claim 7.

11. the third conductor has an electrode pattern electrically connecting the first conductor and the second conductor, and a third wiring pattern electrically connected to a side of the second conductor farther from the RFIC chip and extending in a direction away from the RFIC chip, The third wiring pattern is disposed so as to overlap at least a portion of the second opening in a plan view. The RFID module according to claim 7.

12. the first radiating element has a first conductor and a second conductor which are metal plates, and a third conductor arranged on a first main surface side of the first substrate, the first conductor is disposed adjacent to the RFIC chip, and the second conductor is disposed on an opposite side of the RFIC chip with respect to the first conductor; the first conductor, the second conductor, and the third conductor are electrically connected to each other; The RFID module according to claim 1 .

13. The first conductor and the second conductor have a rectangular first frame and a second frame connected to the first frame so as to divide the first frame into two. The RFID module according to claim 12.

14. the first conductor and the second conductor each have two sides and one bottom side, and each have a concave third frame and a fourth frame connecting the first conductor and the second conductor at central portions of the two sides; The fourth frames of the first conductor and the second conductor are arranged to face each other. The RFID module according to claim 12.

15. The pattern of the second radiating element is rectangular. The RFID module according to claim 1 .