RFID module

Abstract

An RFID module is provided with: a substrate; a first electrode and a second electrode disposed on the substrate; a coil element, one side of which is connected to the first electrode and the other side of which is connected to the second electrode; an RFIC chip electrically connected to the first electrode and the second electrode; and a first insulating layer that covers the RFIC chip. The coil element is wound around the substrate, and at least a portion of the coil element is exposed outside the first insulating layer.

Description

Technical Field

[0001] The present invention relates to an RFID module having a substrate on which a coil conductor is mounted. Background Art

[0002] Conventionally, products are managed by attaching an RFID (Radio-Frequency Identification) module as a wireless communication device to products. As one form of RFID module, there is an RFID module in which a coil conductor functioning as an antenna is arranged on an insulating substrate together with an RFIC (Radio-Frequency Integrated Circuit) chip.

[0003] For example, Patent Document 1 proposes an RFID module including a coil conductor formed by arranging coil bodies having legs for mounting in a row.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2018-235714 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] Since the coil conductor of the RFID module disclosed in Patent Document 1 is disposed inside the mold, the opening of the coil conductor is narrow, and the communication characteristics as an antenna are degraded.

[0009] An object of the present invention is to provide an RFID module with improved communication characteristics.

[0010] Solutions for solving problems

[0011] An RFID module according to a technical solution of the present invention comprises: a substrate; a first electrode and a second electrode, which are arranged on the substrate; a coil element, one side of which is connected to the first electrode and the other side of which is connected to the second electrode; an RFIC chip, one end of which is electrically connected to the first electrode and the other end of which is electrically connected to the second electrode; and a first insulating layer, which covers the RFIC chip. The coil element is wound on the substrate, and at least a part of it is exposed outside the first insulating layer.

[0012] Effects of the Invention

[0013] According to the present invention, it is possible to provide an RFID module having improved communication characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1This is a perspective view showing a schematic structure of the RFID module according to the first embodiment.

[0015] Figure 2 is a perspective side view of the RFID module.

[0016] Figure 3 This is a longitudinal sectional view of the RFID module with the coil element omitted.

[0017] Figure 4 It is a plan view showing electrodes arranged on a substrate.

[0018] Figure 5 It is an explanatory diagram for explaining the opening area.

[0019] Figure 6 It is an explanatory diagram for explaining a method for forming a resist layer.

[0020] Figure 7 This is a plan view showing a schematic structure of an RFID module according to the second embodiment.

[0021] Figure 8 yes Figure 7 AA line section view.

[0022] Fig. 9 This is a longitudinal sectional view of the RFID module according to the third embodiment.

[0023] Fig.10 It is a top view showing electrodes arranged on a substrate according to the third embodiment.

[0024] Fig.11 This is a side view of the RFID module according to the fourth embodiment.

[0025] Fig.12 This is a longitudinal sectional view of the RFID module according to the fourth embodiment.

[0026] Fig.13 This is an equivalent circuit diagram of the RFID module according to the fourth embodiment. DETAILED DESCRIPTION

[0027] The embodiments described below all illustrate a specific example of the present invention, and the present invention is not limited to this structure. In addition, the numerical values, shapes, structures, steps, the order of steps, etc. specifically shown in the following embodiments represent an example and do not limit the present invention. Among the constituent elements of the following embodiments, the constituent elements that are not recorded in the independent claims representing the highest concept are described as arbitrary constituent elements. In addition, in all embodiments, the structures of the various modified examples are also the same, and the structures recorded in the various modified examples can also be combined separately.

[0028] (Implementation Method 1)

[0029] Next, refer to Figure 1 to Figure 3 A schematic configuration of an RFID module 1 according to Embodiment 1 of the present invention will be described. Figure 1 This is a perspective view of the RFID module 1 according to the first embodiment. Figure 2 is a perspective side view of the RFID module 1 . Figure 3 6 is a longitudinal sectional view of the RFID module 1 with the coil element 6 omitted. In the figure, the XYZ coordinate system is for the purpose of making the invention easier to understand and does not limit the invention. The X-axis direction represents the length direction of the RFID module 1, the Y-axis direction represents the depth (width) direction, and the Z-axis direction represents the thickness direction. The X-direction, the Y-direction, and the Z-direction are orthogonal to each other. In addition, in the embodiment, the positive direction of the Z-axis is described as the upward direction and the negative direction of the Z-axis is described as the downward direction.

[0030] The RFID module 1 of the embodiment includes a substrate 3, a coil element 6 and an RFIC chip 7 arranged on a first main surface 4 which is an upper surface of the substrate 3, and a resin layer 10 sealing the coil element 6 and the RFIC chip 7. The RFID module 1 is, for example, a cube or a rectangular parallelepiped.

[0031] The RFIC chip 7 has a first terminal 8 and a second terminal 9 as input / output terminals. The substrate 3 of the first embodiment is a double-sided substrate, and the second main surface 5 and the first main surface 4 as the lower surface of the substrate 3 are opposite to each other. The substrate 3 is insulating, for example, a glass epoxy substrate, a ceramic substrate, etc.

[0032] A resist layer 17 is stacked on the second main surface 5 of the substrate 3. The resist layer 17 covers and protects a first electrode 29 and a second electrode 31, which are described later and are arranged on the second main surface 5. The resist layer 17 is, for example, an insulating resin layer.

[0033] like Figure 1 and Figure 2 As shown, the coil element 6 is formed by winding the conductive wire 41 multiple times along the winding axis Wa, and the coil element 6 functions as an antenna. The communication frequency band of the RFID module 1 of the embodiment is, for example, the UHF band of 860MHz to 960MHz. The number of turns and size of the coil element 6 can also be changed in accordance with the communication characteristics.

[0034] The coil element 6 has a first end 44 connected to the first electrode 29 and a second end 45 connected to the second electrode 31. The coil element 6 is an air-core coil having a hollow inside. The pitch of the winding of the wire 41 is larger than the wire diameter of the wire 41. Thus, the coil element 6 has a gap between the wound and adjacent wires 41, so that the magnetic field generated by the coil element 6 is easily released to the outside, and magnetic field coupling is easily performed, thereby improving the communication characteristics.

[0035] The conductive wire 41 may have a conductive core wire and an insulating film covering the outer circumference of the core wire, or may be composed of only the core wire. In the case where the conductive wire 41 has an insulating film, the insulating film is stripped off the respective joining portions of the coil element 6 and the first electrode 29 and the second electrode 31, so that the core wire is joined to each electrode. The conductive wire 41 and the first electrode 29 and the second electrode 31 are fixed by heating or laser irradiation. After the conductive wire 41 is connected to either the first electrode 29 or the second electrode 31, the coil element 6 is wound around the substrate 3 and the resin layer 10, and then connected to the other of the first electrode 29 and the second electrode 31. In the case where the conductive wire 41 is composed of only the core wire, an insulating film is formed on the coil element 6 exposed from the substrate 3 and the resin layer 10.

[0036] like Figure 3 As shown, a resin layer 10 as a first insulating layer seals the RFIC chip 7 and is stacked on the first main surface 4 of the substrate 3. The resin layer 10 is formed of a common sealing resin such as epoxy resin.

[0037] Next, refer to Figure 3 and Figure 4 The substrate 3 will be described. Figure 4 It is a plan view showing the wiring electrodes on the substrate 3 . Figure 4 (a) is a plan view showing wiring electrodes on the first main surface 4 of the substrate 3 . Figure 4 (b) is a perspective plan view of the substrate 3 , showing the wiring electrodes on the second main surface 5 . Figure 4 The single-dot dash line in represents a through-hole connection.

[0038] like Figure 3 and Figure 4 As shown in (a), the first pad 19 connected to the first terminal 8 of the RFIC chip 7 by means of the solder 23 and the second pad 21 connected to the second terminal 9 of the RFIC chip 7 by means of the solder 23 are arranged on the first main surface 4 as the upper surface of the substrate 3. The electrode 27 opposite to the first pad 19 in the longitudinal direction of the substrate 3 and the conductor pattern 25 connecting the first pad 19 and the electrode 27 are also arranged on the first main surface 4 of the substrate 3. The conductor pattern 25 is, for example, a straight line shape extending in the longitudinal direction of the substrate 3.

[0039] The second interlayer connection conductor 57 and the first interlayer connection conductor 55 are formed penetrating the inside of the substrate 3. The first interlayer connection conductor 55 is a conductive via connecting the electrode 27 and the first electrode 29. The second interlayer connection conductor 57 is a conductive via connecting the second pad 21 and the second electrode 31.

[0040] The first interlayer connection conductor 55 and the second interlayer connection conductor 57 are, for example, conductors formed by curing (metallizing) a conductive paste filled in a hole provided in the insulating substrate 3, but may also be a plated through hole. The first interlayer connection conductor 55 and the second interlayer connection conductor 57 are respectively arranged opposite to each other in the longitudinal direction of each third substrate.

[0041] A first electrode 29 and a second electrode 31 connected to a first end 44 and a second end 45 of the coil element 6 are arranged on the second main surface 5 of the substrate 3. The first electrode 29 and the second electrode 31 face each other in the longitudinal direction of the substrate 3.

[0042] The first terminal 8 of the RFIC chip 7 is connected to the first end portion 44 of the coil element 6 via the solder 23 , the first pad 19 , the conductor pattern 25 , the electrode 27 , the first interlayer connection conductor 55 , and the first electrode 29 .

[0043] The second terminal 9 of the RFIC chip 7 is connected to the second end portion 45 of the coil element 6 via the solder 23 , the second pad 21 , the second interlayer connection conductor 57 , and the second electrode 31 .

[0044] An LC parallel resonant circuit is formed in the RFID module 1 to match the radio wave of the communication frequency. Therefore, when the coil element 6 receives the radio wave of the communication frequency, current flows in the RFIC chip 7 .

[0045] The portion of the conductive wire 41 of the coil element 6 that is in contact with the second main surface 5 side of the substrate 3 and the first electrode 29 and the second electrode 31 on the second main surface are covered and protected by the anti-etching layer 17. This prevents the external metal of the RFID module 1 from being short-circuited with the coil element 6, the first electrode 29, and the second electrode 31, and prevents the resonance frequency of the RFIC chip 7 from being affected.

[0046] For one turn of the wire 41 of the coil element 6, the wire 41 protrudes from the inside of one side surface of the anti-etching layer 17 of the RFID module 1 to the outside, and then is successively wound around the substrate 3 and one side surface of the resin layer 10, the upper surface of the resin layer 10, the substrate 3 and the surface of the resin layer 10 opposite to the one side surface, and again enters the inside from the surface opposite to the one side surface of the anti-etching layer 17. In this way, the coil element 6 is wound around the periphery of the resin layer 10.

[0047] Since the longitudinal section of the RFID module 1 perpendicular to the winding axis Wa of the coil element 6 is rectangular, the opening P of the coil element 6 formed by the wire 41 wound around a part of the outer periphery of the RFID module 1 is also rectangular. Figure 5 (a) is a rectangle when viewed from the winding axis Wa. Figure 5Compared with the circular coil element 91 shown in (b), when the diameter R of the circle and the length L of the side of the rectangle are the same, the opening area of ​​the rectangular opening is larger, so the antenna characteristics of the RFID module 1 of the first embodiment are better.

[0048] The manufacturing process of the RFID module 1 is described. First, on a large-sized double-sided substrate, copper foil is patterned by, for example, photolithography to form a first pad 19, a second pad 21, a conductor pattern 25, an electrode 27, a first electrode 29, and a second electrode 31 as conductors. At this time, the wiring of a plurality of RFID modules 1 is patterned.

[0049] Next, the RFIC chip 7 is mounted on each of the first pad 19 and the second pad 21, and the RFIC chip 7 of the substrate is molded using the resin layer 10. Next, the large-sized double-sided substrate after molding is singulated into modules one by one by cutting. At this time, a barrel grinding process can also be performed to remove the corners of the singulated modules. Next, as shown in FIG. Figure 6 As shown, by immersing the second main surface 5 side of the substrate 3 of the singulated module 2 in, for example, a UV curable resin liquid 101 so that the UV curable resin liquid 101 adheres to the second main surface 5 side and irradiates UV, an anti-corrosion layer 17 can be formed, and the RFID module 1 can be manufactured.

[0050] As described above, the RFID module 1 of the first embodiment includes: a substrate 3; a first electrode 29 and a second electrode 31, which are arranged on the substrate 3; a coil element 6, one side of which is connected to the first electrode 29 and the other side of which is connected to the second electrode 31; an RFIC chip 7, one end of which is electrically connected to the first electrode 29 and the other end of which is electrically connected to the second electrode 31; and a resin layer 10, which covers the RFIC chip 7. The coil element 6 is wound around the substrate 3, and at least a part of it is exposed outside the resin layer 10.

[0051] According to the RFID module 1 of this structure, since at least a part of the coil element 6 is exposed outside the resin layer 10, a part of the coil element 6 reaches the outer periphery of the RFID module 1, and the opening of the coil element 6 can be expanded. As a result, the magnetic field can be widely radiated from the coil element 6, and the communication characteristics of the coil element 6 as an antenna can be improved.

[0052] By placing the RFID module 1 in a metal coil spring, for example, the coil spring can be excited, thereby extending the communication distance.

[0053] In addition, the substrate 3 has a first main surface 4 and a second main surface 5 facing each other, an RFIC chip 7 is arranged on the first main surface 4 side, and a first electrode 29 and a second electrode 31 are arranged on the second main surface 5 side. The RFID module 1 has a resin layer 10 covering the RFIC chip 7 on the first main surface 4, and an anti-etching layer 17 covering the first electrode 29 and the second electrode 31 on the second main surface 5. The coil element 6 is wound around the substrate 3 and the resin layer 10.

[0054] Thus, the coil element 6 can be exposed to the outside of the upper surface and the side surface of the resin layer 10 , so that the opening of the coil element 6 can be increased, and the communication characteristics can be further improved.

[0055] (Implementation Method 2)

[0056] Next, refer to Figure 7 and Figure 8 An RFID module 1A according to the second embodiment will be described. Figure 7 It is a plan view showing a schematic structure of an RFID module 1A according to the second embodiment. Figure 8 yes Figure 7 AA line section view.

[0057] The substrate 3A of the second embodiment is a single-sided substrate. The RFID module 1A of the second embodiment is the same as the RFID module 1 of the first embodiment in terms of configuration other than this and the points described below, and description of the common configuration is omitted.

[0058] The thickness of the substrate 3A in the second embodiment is larger than the thickness of the substrate 3 in the first embodiment, and is, for example, about 1 mm.

[0059] The first pad 19A of the second embodiment extends from the central portion of the substrate 3A to one end side in the longitudinal direction, and the second pad 21A extends from the central portion of the substrate 3A to the other end side in the longitudinal direction. The first end 44A of the coil element 6A is connected to one end side of the first pad 19A, and the second end 45A of the coil element 6A is connected to the other end side of the second pad 21A. The first pad 19A on the central portion side of the substrate 3A is connected to the first terminal 8 of the RFIC chip 7 by means of the solder 23. The second pad 21A on the central portion side of the substrate 3A is connected to the second terminal 9 of the RFIC chip 7 by means of the solder 23.

[0060] In the first pad 19A, an insulating anti-etching layer 18 is laminated on the side opposite to the substrate 3A side, except for the connection portion connected to the first end 44A of the coil element 6A and the connection portion connected to the solder 23. In the second pad 21A, an insulating anti-etching layer 18 is laminated on the side opposite to the substrate 3A side, except for the connection portion connected to the second end 45A of the coil element 6A and the connection portion connected to the solder 23. Thus, even if the lead wire 41 of the coil element 6A is wound around the substrate 3A, the first pad 19A, and the second pad 21A from one end side of the first pad 19A, conduction between the coil element 6A and the first pad 19A and the second pad 21A can be prevented.

[0061] The conductor 41 of the coil element 6A of the second embodiment has a conductive core wire and an insulating film covering the outer periphery of the core wire. In this case, the second main surface 5A of the RFID module 1A can also be arranged on the metal surface in a manner opposite to the metal surface to communicate. In this case, the RFID module 1A can excite the metal surface to communicate. In the case where the conductor 41 is composed only of the core wire, a resin layer covering the coil element 6A on the second main surface 5A side of the substrate 3A can also be formed.

[0062] An insulating resin layer 10A covering the RFID module 1A, the first pad 19A, the second pad 21A, and the coil element 6A is laminated on the first main surface 4A side of the substrate 3A. The resin layer 10A does not need to be formed by resin molding, and can be formed by, for example, UV curing resin. In this case, since the resin layer is not formed by resin molding, the RFID module 1 can be manufactured at a low cost.

[0063] In addition, if Figure 7 As shown in FIG. 1 , the RFIC chip 7 is disposed at the center of the coil element 6A in the longitudinal direction in a plan view. Since the coil element 6A is symmetrically disposed around the RFIC chip 7, symmetrical communication characteristics can be obtained.

[0064] In addition, on the first main surface 4A side of the substrate 3A, the coil element 6A and the RFIC chip 7 do not overlap when viewed from above. This can reduce the influence of the magnetic field induced by the current flowing in the coil element 6A on the RFIC chip 7. In addition, the load applied to the RFIC chip due to the tension of the winding of the coil element can be reduced.

[0065] According to the RFID module 1A of the second embodiment, the substrate 3A has a first main surface 4A and a second main surface 5A facing each other, and an RFIC chip 7, a first pad 19A as a first electrode, and a second pad 21A as a second electrode are arranged on the first main surface 4A side. The coil element 6A is wound on the substrate 3A, and at least a part of it is exposed outside the resin layer 10A.

[0066] Thus, in the RFID module 1A of the second embodiment, similarly to the RFID module 1 of the first embodiment, at least a portion of the coil element 6A is exposed outside the resin layer 10A, so that the communication characteristics of the coil element 6 as an antenna can be improved.

[0067] (Implementation 3)

[0068] Next, refer to Fig. 9 and Fig.10 The RFID module 1B according to the third embodiment will be described. Fig. 9 It is a plan view showing a schematic structure of an RFID module 1B according to the third embodiment in which the coil element is omitted. Fig.10 It is a plan view showing electrodes arranged on the substrate 3 .

[0069] In the third embodiment, the connection point between the interlayer connection conductor and the electrode disposed on the second main surface 5 of the substrate 3 and the connection point between the electrode and the coil element 6 are located at offset positions. With respect to the structure other than this point and the points described below, the RFID module 1B of the third embodiment is the same as the RFID module 1 of the first embodiment, and the description related to the common structure is omitted.

[0070] like Fig. 9 and Fig.10 As shown in (a), a first pad 19B connected to the first terminal 8 of the RFIC chip 7 via solder 23 and a second pad 21B connected to the second terminal 9 of the RFIC chip 7 via solder 23 are arranged on the first main surface 4 which is the upper surface of the substrate 3.

[0071] The first pad 19B has an electrode 19Ba connected to the first terminal 8 of the RFIC chip 7 and an electrode 19Bb extending outward from the electrode 19Ba in the length direction of the substrate 3. The front end of the electrode 19Bb is connected to the upper end of the first interlayer connection conductor 55B penetrating the substrate 3, and the lower end of the first interlayer connection conductor 55B is connected to the first electrode 29B arranged on the second main surface 5 which is the lower surface of the substrate 3.

[0072] The second pad 21B has an electrode 21Ba connected to the second terminal 9 of the RFIC chip 7 and an electrode 21Bb extending outward from the electrode 21Ba in the length direction of the substrate 3. The front end of the electrode 21Bb is connected to the upper end of the second interlayer connection conductor 57B penetrating the substrate 3, and the lower end of the second interlayer connection conductor 57B is connected to the second electrode 31B arranged on the second main surface 5 as the lower surface of the substrate 3.

[0073] The first electrode 29B disposed on the second main surface 5 of the substrate 3 includes an electrode 29Ba connected to the first interlayer connection conductor 55B, a wiring 29Bb extending outward from the electrode 29Ba in the longitudinal direction of the substrate 3, and an electrode 29Bc connected to the end of the wiring 29Bb on the outer side. The electrode 29Bc is connected to the first end 44 of the coil element 6.

[0074] The second electrode 31B disposed on the second main surface 5 of the substrate 3 includes an electrode 31Ba connected to the second interlayer connection conductor 57B, a wiring 31Bb extending outward from the electrode 31Ba in the longitudinal direction of the substrate 3, and an electrode 31Bc connected to the end of the wiring 31Bb on the outer side. The electrode 31Bc is connected to the second end 45 of the coil element 6.

[0075] The electrode 29Ba and the wiring 29Bb of the first electrode 29B are protected by being covered by the anti-etching layer 61. In addition, the electrode 31Ba and the wiring 31Bb of the second electrode 31B are protected by being covered by the anti-etching layer 61. The connection portion between the coil element 6 and each of the electrodes 29Bc and 31Bc arranged on the second main surface 5 of the substrate 3 is exposed and is not covered by the anti-etching layer 61.

[0076] The first terminal 8 of the RFIC chip 7 is connected to the first end 44 of the coil element 6 via the solder 23, the first pad 19B, the first interlayer connection conductor 55B and the first electrode 29B. The second terminal 9 of the RFIC chip 7 is connected to the second end 45 of the coil element 6 via the solder 23, the second pad 21B, the second interlayer connection conductor 57B and the second electrode 31B.

[0077] In the electrode on the second main surface 5 of the substrate 3 connected to the interlayer connection conductor and the coil element, if the electrode and the coil element are connected on the extension line of the interlayer connection conductor, there is a possibility that the connection with the coil element is affected by the height difference of the interlayer connection conductor.

[0078] The RFID module 1B of the third embodiment includes: a first interlayer connection conductor 55B that penetrates the substrate 3 and connects the RFIC chip 7 and the first electrode 29B; and a second interlayer connection conductor 57B that penetrates the substrate 3 and connects the RFIC chip 7 and the second electrode 31B. The electrode 29Bc, which is the connection point between the first electrode 29B and the coil element 6, is located at a position on the outside of the length direction of the substrate 3 relative to the electrode 29Ba, which is the connection point between the first electrode 29B and the first interlayer connection conductor 55B. The electrode 31Bc, which is the connection point between the second electrode 31B and the coil element 6, is located at a position on the outside of the length direction of the substrate 3 relative to the electrode 31Ba, which is the connection point between the second electrode 31B and the second interlayer connection conductor 57B. In this way, since the electrode 29Ba connected to the first interlayer connection conductor 55B and the electrode 29Bc connected to the first end portion 44 of the coil element 6 are located at separate positions, it is possible to prevent the height difference of the connection portion between the first interlayer connection conductor 55B and the electrode 29Ba from affecting the connection between the first end portion 44 of the coil element 6 and the electrode 29Bc. Similarly, the height difference of the connection portion between the second interlayer connection conductor 57B and the electrode 31Ba can be prevented from affecting the connection between the second end portion 45 of the coil element 6 and the electrode 31Bc.

[0079] In the RFID module 1B of the third embodiment, the matching capacitor 11 is connected in parallel with the RFIC chip 7 at the electrode 19Ba of the first pad 19B and the electrode 21Ba of the second pad 21B. The resonant frequency of the RFID module 1B can be reduced by using the capacitance component of the capacitor 11. In addition, the RFID module 1B may also be configured without the capacitor 11.

[0080] (Implementation 4)

[0081] Next, refer to Figure 11 to Figure 13 An RFID module 1C according to a fourth embodiment will be described. Fig.11 It is a side view showing a schematic structure of an RFID module 1C according to the third embodiment. Fig.12 It is a longitudinal sectional view of the RFID module 1C. Fig.13 is an equivalent circuit diagram of the RFID module 1C.

[0082] The coil element 6C of the fourth embodiment is wound in the length direction of the substrate 3 and extends to a position outside the substrate 3 and the resin layer 10. With respect to the structure other than this point and the points described below, the RFID module 1C of the fourth embodiment is the same as the RFID module 1 of the first embodiment or the RFID module 1B of the third embodiment, and the description related to the common structure is omitted.

[0083] like Fig.12As shown, first pads 19C connected to first terminals 8 of RFIC chip 7 via solder 23 and second pads 21C connected to second terminals 9 of RFIC chip 7 via solder 23 are arranged on first principal surface 4 as the upper surface of substrate 3 .

[0084] In the longitudinal direction of the substrate 3, the outer end of the first pad 19C is connected to the upper end of the first interlayer connection conductor 55 that penetrates the substrate 3, and the lower end of the first interlayer connection conductor 55 is connected to the first electrode 29 arranged on the second main surface 5 of the substrate 3. The first electrode 29 is joined to the first connection portion 44C of the coil element 6C by, for example, solder 47. The first electrode 29 and the first connection portion 44C of the coil element 6C may be joined electrically by welding or ultrasonic waves other than solder 47.

[0085] In the longitudinal direction of the substrate 3, the outer end of the second pad 21C is connected to the upper end of the second interlayer connection conductor 57 penetrating the substrate 3, and the lower end of the second interlayer connection conductor 57 is connected to the second electrode 31 arranged on the second main surface 5 of the substrate 3. The second electrode 31 is joined to the second connection portion 45C of the coil element 6C by, for example, solder 47. The second electrode 31 and the second connection portion 45C of the coil element 6C may be joined electrically by welding or ultrasonic waves other than solder 47.

[0086] like Fig.13 As shown, the RFIC chip 7 has a feed point 7a and a capacitor C1 inside. The first terminal 8 electrically connected to one side of the feed point 7a and the capacitor C1 is connected to the first connection portion 44C of the coil element 6C via the solder 23, the first pad 19C, the first interlayer connection conductor 55 and the first electrode 29. The second terminal 9 electrically connected to the other side of the feed point 7a and the capacitor C1 is connected to the second connection portion 45C of the coil element 6C via the solder 23, the second pad 21C, the second interlayer connection conductor 57 and the second electrode 31.

[0087] The joint portion between the first electrode 29 and the first connecting portion 44C of the coil element 6C joined by solder 47 is covered and protected by an insulating resist layer 17 such as resin. The joint portion between the second electrode 31 and the second connecting portion 45C of the coil element 6C joined by solder 47 is also covered and protected by an resist layer 17.

[0088] The coil element 6C includes a first coil extension portion 6Ca and a second coil extension portion 6Cb that protrude in the longitudinal direction of the substrate 3, respectively, from the substrate 3 and the resin layer 10. Thus, the coil element 6C functions as a dipole antenna, and thus communication performance can be further improved.

[0089] As described above, according to the RFID module 1C of the fourth embodiment, the coil element 6C has the first coil extension portion 6Ca extending further toward the outside of the substrate 3 from the connection portion connected to the first electrode 29 on one side, and has the second coil extension portion 6Cb extending further toward the outside of the substrate 3 from the connection portion connected to the second electrode 31 in the direction opposite to the direction in which the first coil extension portion 6Ca extends on the other side. Thus, the communication performance of the RFID module 1C can be further improved.

[0090] The present invention is not limited to the above-described embodiments, and can be implemented in the following modified forms.

[0091] In the above-mentioned Embodiment 1, the RFIC chip 7 is arranged at the end of the substrate 3, but it is not limited to this. The RFIC chip 7 may also be arranged at the central part of the substrate 3 together with the first pad 19 and the second pad 21 as in Embodiment 2. Thus, the RFIC chip 7 is arranged at the central part of the length direction of the coil element 6 when viewed from above. When the coil element 6 is symmetrically arranged with the RFIC chip 7 as the center, symmetrical communication characteristics can be obtained. In addition, the load when the coil element 6 is connected to the first electrode 29 and the second electrode 31 can be reduced. The situation of transferring to the RFIC chip 7.

[0092] In each embodiment, the present invention is described with a certain degree of detail, but the disclosure of these embodiments may vary in structural details, and the combination and sequence of elements of each embodiment may be implemented without departing from the scope and concept of the claimed invention.

[0093] The RFID module of the first technical solution of the present invention comprises: a substrate; a first electrode and a second electrode, which are arranged on the substrate; a coil element, one side of which is connected to the first electrode and the other side is connected to the second electrode; an RFIC chip, one end of which is electrically connected to the first electrode and the other end of which is electrically connected to the second electrode; and a first insulating layer, which covers the RFIC chip. The coil element is wound on the substrate, and at least a part of it is exposed outside the first insulating layer.

[0094] According to the RFID module of this technical solution, since at least a part of the coil element is exposed outside the first insulating layer, a part of the coil element reaches the outer periphery of the RFID module, and the opening of the coil element can be enlarged. As a result, the magnetic field can be widely radiated from the coil element, and the communication characteristics of the coil element as an antenna can be improved.

[0095] According to the second technical solution, in the RFID module of the first technical solution, the coil element has a conductor wound multiple times, and the pitch of the conductor winding is larger than the wire diameter of the conductor. As a result, the coil element has a gap between the wound and adjacent conductors, so the magnetic field generated by the coil element is easily released to the outside, and magnetic field coupling is easily performed, thereby improving communication characteristics.

[0096] According to the third technical solution, in the RFID module of the first technical solution or the second technical solution, the substrate has a first main surface and a second main surface facing each other, an RFIC chip is arranged on the first main surface side, a first electrode and a second electrode are arranged on the second main surface side, a first insulating layer covering the RFIC chip is arranged on the first main surface, a second insulating layer covering at least a part of the first electrode and the second electrode is provided on the second main surface, and a coil element is wound on the substrate and the first insulating layer. Thus, a double-sided substrate can be used as the substrate, and such a structure can also realize an RFID module with improved communication characteristics.

[0097] According to the fourth technical solution, in any one of the RFID modules of the first to third technical solutions, the cross section of the first insulating layer perpendicular to the winding axis of the coil element is rectangular. Since the opening of the coil element can be set to a rectangular shape, the communication characteristics can be improved compared to the coil element with a circular opening.

[0098] According to the fifth technical solution, the substrate of the first technical solution or the second technical solution has a first main surface and a second main surface facing each other, and an RFIC chip, a first electrode, and a second electrode are arranged on the first main surface side. Thus, a single-sided substrate can be used as the substrate, and such a structure can also realize an RFID module with improved communication characteristics.

[0099] According to the sixth technical solution, in any one of the first to third technical solutions, the RFIC chip is arranged at the longitudinal center of the coil element in a plan view. Thus, the coil elements are symmetrically arranged around the RFIC chip, thereby obtaining symmetrical communication characteristics.

[0100] According to the seventh technical solution, in the RFID module of the sixth technical solution, the coil element and the RFIC chip do not overlap in a plan view on the first main surface side of the substrate. This can reduce the influence of the magnetic field induced by the current flowing in the coil element on the RFIC chip.

[0101] According to the eighth technical solution, in the RFID module of the third technical solution, there is provided: a first interlayer connection conductor, which penetrates the substrate to connect the RFIC chip and the first electrode; and a second interlayer connection conductor, which penetrates the substrate to connect the RFIC chip and the second electrode. The connection point between the first electrode and the coil element is located at a position closer to the outside of the length direction of the substrate than the connection point between the first electrode and the first interlayer connection conductor, and the connection point between the second electrode and the coil element is located at a position closer to the outside of the length direction of the substrate than the connection point between the second electrode and the second interlayer connection conductor. Thus, it is possible to reduce the situation in which the height difference between the connection part between each interlayer connection conductor and the electrode affects the connection part between the coil element and each electrode.

[0102] According to the ninth technical solution, in the RFID module of the third technical solution or the eighth technical solution, the coil element has a first coil extension portion extending from the connection portion connected to the first electrode further to the outside of the substrate 3 on one side, and has a second coil extension portion extending from the connection portion connected to the second electrode further to the outside of the substrate 3 in a direction opposite to the direction in which the first coil extension portion extends on the other side. Thus, the communication characteristics can be improved.

[0103] Description of Reference Numerals

[0104] 1. 1A, RFID module; 2. module; 3. 3A, substrate; 4. 4A, first main surface; 5. 5A, second main surface; 6. 6A, 6C, coil element; 7. RFIC chip; 7a, power supply point; 8. first terminal; 9. second terminal; 10. 10A, resin layer; 11. capacitor; 17. anti-etching layer; 18. anti-etching layer; 19. 19A, 19B, 19C, first pad; 21. 21A, 21B, 21C, second pad; 23. solder; 25. conductor pattern; 27. electrode; 29, 29B , the first electrode; 29Ba, the electrode; 29Bb, the wiring; 29Bc, the electrode; 31, 31B, the second electrode; 31Ba, the electrode; 31Bb, the wiring; 31Bc, the electrode; 41, the wire; 44, 44A, the first end; 44C, the first connecting portion; 45, 45A, the second end; 45C, the second connecting portion; 47, the solder; 55, 55B, the first interlayer connecting conductor; 57, the second interlayer connecting conductor; 61, the anti-etching layer; 91, the coil element; 101, the UV curing resin liquid; Wa, the winding axis.

Claims

1. An RFID module, wherein: The RFID module has: substrate; a first electrode and a second electrode, wherein the first electrode and the second electrode are arranged on the substrate; a coil element, one side of which is connected to the first electrode, and the other side of which is connected to the second electrode; an RFIC chip electrically connected to the first electrode and the second electrode; as well as a first insulating layer covering the RFIC chip, The coil element is wound around the substrate, and at least a portion of the coil element is exposed outside the first insulating layer.

2. The RFID module according to claim 1, wherein: The coil element has a conductive wire wound multiple times. The pitch of the wire winding is larger than the wire diameter of the wire.

3. The RFID module according to claim 1 or 2, wherein: The substrate has a first main surface and a second main surface facing each other, The RFIC chip is arranged on the first main surface side, The first electrode and the second electrode are arranged on the second main surface side, The first insulating layer is arranged on the first main surface, A second insulating layer covering at least a portion of the first electrode and the second electrode is provided on the second main surface. The coil element is wound around the substrate and the first insulating layer.

4. The RFID module according to any one of claims 1 to 3, wherein: A cross section of the first insulating layer perpendicular to the winding axis of the coil element is rectangular.

5. The RFID module according to claim 1 or 2, wherein: The substrate has a first main surface and a second main surface facing each other, The RFIC chip, the first electrode, and the second electrode are arranged on the first main surface side.

6. The RFID module according to any one of claims 1 to 3, wherein: The RFIC chip is arranged at a center portion in a longitudinal direction of the coil element in a plan view.

7. The RFID module according to claim 6, wherein: On the first main surface side of the substrate, the coil element and the RFIC chip do not overlap in a plan view.

8. The RFID module according to claim 3, wherein: The RFID module has: a first interlayer connection conductor that penetrates the substrate and connects the RFIC chip and the first electrode; and a second interlayer connection conductor that penetrates the substrate and connects the RFIC chip and the second electrode, The connection point between the first electrode and the coil element is located outside the connection point between the first electrode and the first interlayer connection conductor in the substrate length direction. A connection point between the second electrode and the coil element is located outside in the substrate longitudinal direction relative to a connection point between the second electrode and the second interlayer connection conductor.

9. The RFID module according to claim 3 or 8, wherein: The coil element has a first coil extension portion on one side extending from a connection portion connected to the first electrode further toward the outside of the substrate (3). On the other side, there is a second coil extension portion extending from a connection portion connected to the second electrode further toward the outside of the substrate (3) in a direction opposite to the direction in which the first coil extension portion extends.

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