JP2007243296A - Rfid tag and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an RFID tag which is so object-free that it can be attached, irrespective of the type of an object such as a conductive object or non-conductive object while it has a simple structure in which an antenna pattern and an IC chip are provided on the surface of the RFIC tag, and to provide a method of manufacturing the same and an attaching method thereof. <P>SOLUTION: The RFID tag is provided with a dielectric substrate, a ground conductor provided on one main surface of this dielectric substrate, a patch conductor provided on the other main surface of the dielectric substrate and having a formed slot, electric connections each extending from an opposite portion of the slot to the inside, and an IC chip arranged in the inside of the slot and connected to the electric connection portion. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, the RFID tag receives a command signal transmitted from a radio frequency identification (hereinafter referred to as RFID) reader / writer, and the tag information stored in the memory in the RFID tag is determined according to the information of the command signal. RFID tags of UHF band and microwave band RFID systems that are used for biometric / article entry / exit management, logistics management, etc. The present invention relates to the manufacturing method and the installation method.

  The RFID system is a system that performs wireless communication between an RFID tag including an IC chip and an RFID reader / writer. There are two types of RFID tags: an active type tag that is equipped with a battery and is driven by the electric power, and a passive type tag that is driven by receiving electric power from a reader / writer. Since the active type has a battery compared to the passive type, there are advantages such as communication distance and communication stability, but there are also disadvantages such as complicated structure, larger size, and higher cost. In addition, with recent improvements in semiconductor technology, IC tags for passive tags have become smaller and higher performance, and the use of passive tags in a wide range of fields is expected. In the passive induction tag, in the electromagnetic induction method applied to the RFID tag of the long wave band and the short wave band, a voltage is applied to the RFID tag by the electromagnetic induction action between the transmission antenna coil of the reader / writer and the antenna coil of the RFID tag. The IC chip is activated by this voltage to enable communication. Therefore, the RFID tag operates only within the induction electromagnetic field by the RFID reader / writer, and the communication distance becomes about several tens of centimeters.

  In addition, in radio frequency RFID tags such as UHF band and microwave band, the radio wave communication method is applied, and power is supplied to the IC chip of the RFID tag by radio waves, so the communication distance is about 1 to 8 m. And has improved significantly. Therefore, it is possible to read multiple RFID tags at once or read a moving RFID tag, which was difficult to realize with long wave band and short wave band RFID systems with short communication distances. It is thought to spread. For example, Patent Document 1 and Patent Document 2 disclose high frequency passive tags such as UHF band and microwave band.

  Conventionally, in the RFID tag technology, an IC chip 67 is mounted on a dipole antenna 66 shown in FIG. 12 of Patent Document 1 (66 is a dipole antenna and 67 is an IC chip), thereby operating as an RFID system tag. And a half-wavelength microstrip line resonator 13 shown in FIG. 2 of Patent Document 2 (13 is a half-wavelength microstrip line resonator, 14 is a dielectric substrate, and 15 is a ground conductor plate). Since the IC chip is connected to the ground conductor plate 15, even if there is a metal object (conductor) on the ground conductor plate 15 side, the radiation characteristics of the antenna are hardly affected. Some can be pasted.

Japanese Patent Laying-Open No. 2003-249820 (FIG. 12)

Japanese Patent Laid-Open No. 2000-332523 (FIG. 3)

  However, when the RFID tag of Patent Document 1 is attached to a conductive object (conductor) such as a metal object or installed in the vicinity thereof, the dipole antenna 1 does not operate due to the influence of the conductive object, or the communication distance is long. There was a problem that it would be extremely lowered. The RFID tag disclosed in Patent Document 2 can be installed on a metal object (conductor), but has a structure in which an IC chip is connected between a half-wavelength microstrip line resonator and a ground conductor plate. In addition, it is necessary to embed an IC chip inside the dielectric substrate, which causes problems such as a complicated structure and difficulty in manufacturing and an increase in manufacturing cost.

  The present invention has been made in order to solve the above-described problems, and has a simple structure in which an antenna pattern and an IC chip are provided on the surface of an RFID tag and an IC chip does not need to be embedded in a dielectric substrate. It is an object of the present invention to provide an RFID tag that can be installed regardless of a conductive object or a non-conductive object, a manufacturing method thereof, and an installation method thereof.

  The RFID tag according to the invention of claim 1 is provided with a dielectric substrate, a ground conductor portion provided on one main surface of the dielectric substrate, and a slot provided on the other main surface of the dielectric substrate. A patch conductor portion, an electrical connection portion extending inward from an opposing portion of the slot, and an IC chip disposed inside the slot and connected to the electrical connection portion. is there.

  The RFID tag according to a second aspect of the present invention is the RFID tag according to the first aspect, wherein the slot is formed in a central portion of the patch conductor portion and has an elongated shape.

  An RFID tag according to a third aspect of the present invention is the RFID tag according to the first aspect, wherein the slot is formed so as to be wide in the opposite direction from the position where the IC chip is disposed.

  An RFID tag according to a fourth aspect of the present invention is the RFID tag according to any one of the first to third aspects, wherein an adhesive layer capable of adhering to a metal is provided on the opposite side of the ground conductor portion and the dielectric substrate.

  According to a fifth aspect of the present invention, there is provided a RFID tag manufacturing method comprising: a conductor portion forming step of forming a ground conductor portion and a patch conductor portion on one main surface and another main surface of a dielectric substrate; A slot forming step for forming a slot in the slot, an electrical connection portion forming step for forming an electrical connection portion extending from the opposite portion of the slot at the same time as the slot formation, and an IC chip disposed in the slot And a connecting step of connecting the IC chip to the electrical connecting portion.

  The RFID tag installation method according to the invention of claim 6 is a ground conductor portion provided on one main surface of the dielectric substrate, a patch conductor portion provided on the other main surface of the dielectric substrate, and having a slot formed thereon, An RFID tag comprising an electrical connection part extending inward from an opposite part of the slot and an IC chip disposed inside the slot and connected to the electrical connection part, wherein the dielectric is formed on the ground conductor part The RFID tag is placed on the metal by providing an adhesive layer capable of adhering to the metal on the opposite side of the substrate.

  As described above, according to the first aspect of the invention, since the IC chip disposed inside the slot is connected to the electrical connection portion extending from the opposing portion of the slot to the inside, The IC chip is disposed at a position where the electric field in the thickness direction is 0, and there is little adverse effect on the symmetry of the radiation pattern of the patch conductor portion when performing wireless communication with the reader / writer. Is connected to the feeding point, the feeding loss can be greatly reduced, and an RFID tag with an improved communicable distance can be obtained. Furthermore, by forming the electrical connection portion, it is possible to obtain an RFID tag in which the size of an IC chip that can be placed is not limited even when the width of the slot size change is limited.

  According to the invention of claim 2, since the slot is formed in the central portion of the patch conductor portion and has a long and narrow shape, an RFID tag having little adverse effect on the symmetry of the radiation pattern of the patch conductor portion can be obtained. it can.

  According to the invention of claim 3, the slot is formed so as to be wide in the opposite direction from the position where the IC chip is arranged, that is, since the slot is tapered, the communicable bandwidth is reduced. A broadband RFID tag can be obtained.

  According to the invention of claim 4, since the ground conductor portion is provided with the adhesive layer that can be bonded to the metal on the opposite side of the dielectric substrate, it can be installed regardless of whether it is a conductor or a non-conductor. An RFID tag capable of wireless communication with a writer can be obtained.

  According to the invention of claim 5, a conductor portion forming step of forming a ground conductor portion and a patch conductor portion on one main surface and another main surface of the dielectric substrate, respectively, and a slot is formed inside the patch conductor portion A slot forming step, an electrical connection portion forming step for forming an electrical connection portion extending from an opposing portion of the slot at the same time as the slot formation, and an IC chip disposed in the slot, and the IC A connecting step of connecting the chip to the electrical connecting portion, so there is no need to mount the IC chip in a dielectric substrate or to fill the periphery of the IC chip with a connection terminal of the IC chip and Since the electrical connection part, which is the connection part (contact part) with the dielectric substrate, can be formed simultaneously with the patch conductor part, and the conductor pattern is formed on the other main surface (front surface) of the dielectric substrate, The method of manufacturing the RFID tag and feasible RFID tag in the same printed circuit board processing step using the antenna can be obtained.

  According to the invention according to claim 6, since the RFID tag is installed on the metal by providing the ground conductor portion with an adhesive layer that can be bonded to the metal on the side opposite to the dielectric substrate, the installation object is not limited to a conductor or a non-conductor. An RFID tag installation method that can be installed can be obtained.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to FIGS. 1 is a configuration diagram of an RFID tag according to Embodiment 1, FIG. 1 (a) is a surface view of a dielectric substrate, and FIG. 1 (b) is a partial cross-sectional view along line AA ′ of the dielectric substrate. 1C is a partial cross-sectional view taken along line AA ′ of the dielectric substrate, FIG. 2 is a basic configuration diagram of the RFID system, FIG. 2A is an RFID system diagram, and FIG. 3 is a functional block diagram of the RFID tag, FIG. 3 is an electric field diagram of the RFID tag, FIG. 4 is a characteristic impedance diagram of the RFID tag according to the first embodiment, and FIG. 5 is an exposed view of electrical connection parts of the RFID tag according to the first embodiment. 5A is a two-terminal diagram, FIG. 5B is a four-terminal diagram, and FIG. 5C is a line AA ′ of the dielectric substrate of FIGS. 5A and 5B. FIG. 6 is a partial cross-sectional view, FIG. 6 is an enlarged view of a slot of the RFID tag according to the first embodiment, FIG. 6A is a state before mounting an IC chip, and FIG. 1 to 4, reference numeral 1 denotes a dielectric substrate, 2 denotes a ground conductor formed on one main surface (back surface) of the dielectric substrate 1, and 3 denotes another dielectric substrate 1. The patch conductor portion 4 formed on the main surface (surface), 4 is an elongated rectangular slot formed in a part of the patch conductor portion 3, and 5 extends inward from the opposite portion of the slot 4 An electrical connection portion that is electrically continuous with the conductor portion 3, 6 is an IC chip disposed in the slot 4 and connected to the electrical connection portion 5, and 7 is an electrical connection portion 5 formed on the IC chip 6. Connection terminal. Depending on the characteristic impedance of the IC chip 6, the shape of the slot 4 required for impedance matching may be longer than the size of the patch conductor portion 3, so that the slot 4 is not limited to the elongated shape. .

  8 is an RFID tag, 9 is an RFID reader / writer that performs wireless communication with the RFID tag, 10 is an antenna unit provided in the RFID tag 8, and 11 is a transmission wave from the RFID reader / writer 9 received by the antenna unit 10. Is an analog unit that transmits a transmission wave to a subsequent digital circuit, 12 is an A / D conversion unit that performs A / D conversion of the transmission wave, and 13 is an RFID that smoothes the transmission wave received by the antenna unit 10 by a rectifier circuit and generates power A power supply control unit for supplying power and controlling power to each circuit of the tag, 14 is mounted on the RFID tag 8, a memory unit storing tag information such as individual identification information, 15 is a demodulation unit for demodulating a transmission wave, Reference numeral 16 denotes a control unit that controls a circuit in the IC chip 6 including the memory unit 14 using the transmission wave demodulated by the demodulation unit 15, and 17 denotes a control unit 16 that is pulled out from the memory unit 14. 18 is a digital unit composed of a demodulating unit 15, a control unit 16, and a modulating unit 17, and 19 is a D / A converter for a signal coming from the modulating unit and sends it to the analog unit 11. The / A conversion unit 20 is a dummy pad unit. In addition, the patch conductor part 3 does not need to be square, and may be circular or elliptical. In addition, in the RFID tag 8, a circuit subsequent to the antenna unit 11 is constructed in the IC chip 6. In the drawings, the same reference numerals denote the same or corresponding parts, and detailed descriptions thereof are omitted.

  First, the basic operation of the RFID system will be described with reference to FIG. The tag information is stored in the memory unit 14 of the RFID tag 8 in accordance with the use of the RFID system (biological / article entry / exit management and logistics management), and the RFID reader / writer 9 has its own transmission / reception area. The tag information can be updated / written or read when the RFID tag 8 is present or moved (attached to a living body / article subject to entry / exit management or physical distribution management). The RFID reader / writer 9 transmits a command signal for instructing the RFID tag 8 to update, write, or read from the antenna portion of the RFID reader / writer 9 to the RFID tag 8 as a transmission wave. The antenna unit 10 of the RFID tag 8 receives the transmission wave, and the transmission wave is detected and stored (smoothed) by the power supply control circuit 13 to generate an operation power supply for the RFID tag 8, and the operation power supply to each circuit of the RFID tag 8. Supply. Further, the command signal of the transmission wave is demodulated by the demodulator 15. The control unit 16 processes data from the instruction content of the demodulated command signal, and instructs the memory unit 14 to update / write and / or read tag information. A return wave obtained by modulating the read signal output from the unit 14 by the modulation unit 10 is transmitted from the antenna unit 10 to the antenna unit of the RFID reader / writer 9 via the analog unit 11, and the RFID reader / writer 9 receives the read signal. To obtain desired information.

  Next, the structure / manufacturing method and operation of the RFID tag according to the first embodiment will be described with reference to FIGS. In order to form the antenna portion 10 of the RFID tag for wireless communication with the RFID reader / writer 9, a conductor layer is formed on the main surface of the dielectric substrate 1 (conductor portion forming step). The conductor layer on one main surface (back surface) is the ground conductor portion 2 of the RFID tag, and the conductor layer on the other main surface (front surface) is the patch conductor portion 3 having the slots 4. Note that the dielectric substrate 1 may be exposed from the patch conductor portion 3 by the slot 4, and the exposed portion of the dielectric substrate 1 may be coated. The slot 4 is formed in the central portion of the patch conductor portion 3 so that the radiation pattern of the patch conductor portion 3 is good (slot formation step). The dimensions of the slot 4 and the patch conductor portion 3 are the same as those of the patch conductor portion 3. In order to excite, the frequency used in the RFID system is adjusted so that impedance matching between the IC chip 6 described later can be achieved. Note that the thickness and relative dielectric constant of the dielectric substrate 1 are greatly related to the adjustment, so that a desired radiation pattern and gain can be obtained by adjusting and designing these conditions. Further, the electrical connection portion 5 is formed in a part of the patch conductor portion 3 and extends from two sides (long sides of the slot 4 shown in FIG. 1) opposite to the slot 4 toward the center of the patch conductor portion 3. The patch conductor portions 3 are electrically continuous with each other (electrical connection portion forming step), and may be formed simultaneously with the slot formation. The IC chip 6 shown in FIG. 1C is disposed at the position where the electric field in the thickness direction of the substrate is 0 in the center between the electrical connection portions 5 in the slot 4, and is electrically connected to the electrical connection portion 5 by the connection terminals 7. Connected (connection process). Here, the conductor layer (the ground conductor portion 2, the patch conductor portion 3, the electrical connection portion 5) is formed by etching, vapor deposition, milling, or the like, or a printed matter on a film is adhered to the dielectric substrate 1 or the like. A method for processing a printed circuit board is used. On the other hand, since the IC chip 6 can be mounted by using a technique such as thermocompression bonding, an RFID tag having a simple structure can be manufactured only by processing the main surface (front surface / back surface) of the dielectric substrate 1, and the yield can be increased. Can be reduced and manufacturing costs can be reduced. In addition, positioning when mounting the IC chip 6 on the connection terminal 7 and the electrical connection portion 5 may be performed by providing a minute slot (not shown) near the center of the slot 4. There is almost no influence on the electrical characteristics of the tag 8.

  FIG. 3 shows the electric field between the ground conductor part 2 and the patch conductor part 3, and since such an electric field is formed between the conductors, the electric field runs between the opposing portions of the slot 4, and the potential difference is Arise. Therefore, the position where the electric field in the thickness direction of the dielectric substrate 1 is 0 can be used as a feeding point (electrical connection portion 5) of the IC chip, and the feeding loss can be greatly reduced, and the radiation pattern of the patch conductor portion 3 can be reduced. Thus, an RFID tag having a reduced communicable distance and a small adverse effect on the symmetry of the image can be obtained. FIG. 4 shows a change in characteristic impedance of the RFID tag 8 due to a change in the dimensional difference d at the four corners between the ground conductor portion 2 and the patch conductor portion 3, and the horizontal axis d indicates the dimensional difference d using the RIFD tag. What is represented by the wavelength ratio of the frequencies, and R [Ω] and X [Ω] on the vertical axis indicate the real part and the imaginary part of the characteristic impedance, respectively. Here, the dimensional difference between the ground conductor portion 2 and the patch conductor portion 3 refers to the dielectric substrate 1 from the end of the patch conductor portion 3 shown in FIG. 1 (FIG. 4 shows the area of the dielectric substrate 1 and the ground conductor portion. 2 indicates the length d to the end of the same area. Therefore, it can be seen from FIG. 4 that when d is 0.1λ or more, the impedance of the RFID tag 8 is almost constant. Regardless of the non-conductor, and even when floating in the air, the performance does not deteriorate, and wireless communication with the RFID reader / writer 9 becomes possible.

  Here, the RFID tag 8 having the IC chip 6 excited by the patch conductor portion 3 according to the first embodiment will be described using the basic operation of the RFID system described above. “The RFID reader / writer 9 is updated / updated. A command signal for instructing the RFID tag 8 to perform writing, reading, etc. is transmitted as a transmission wave from the antenna portion of the RFID reader / writer 9 to the RFID tag 8. This is a radiation portion of the dielectric substrate 1 constituting the RFID tag 8. When the patch conductor portion 3 receives the transmission wave, a potential difference is generated between the opposing portions of the slot 4, and the transmission wave is supplied to the IC chip 6. The transmission wave supplied to the IC chip 6 is transmitted by the power supply control circuit 13. The power is detected and stored (smoothed) to generate the operating power of the RFID tag 8, the operating power is supplied to each circuit (IC chip 6) of the RFID tag 8, and the operating power is transmitted from the transmission wave. And the tag information is updated / written and / or read from / to the memory unit 14 from the instruction content of the demodulated command signal, and the read signal output from the memory unit 14 is used as a reply wave. The return wave is transmitted from the patch conductor part 3 which is a radiation part to the RFID reader / writer 9 by going back the same path as the transmission wave is supplied to the IC chip 6, and the antenna part of the RFID reader / writer 9 receives the return wave. Thus, it is understood that the same operation as the basic operation of the RFID system can be performed without any problem. Note that the contents of wireless communication data performed by the RFID system may be conventional or new, and the ground conductor portion 2 is formed on the back surface of the dielectric substrate 1. By directing the back side to the installation target surface, it is possible to manufacture a simple structure RFID tag that can be installed regardless of whether the installation target is a conductor or non-conductor at low cost. It can be used in a wide range of fields such as management, equipment management, and car entrance / exit management, and can be installed even if the object to be installed or the surface of the object to be installed is a conductor such as a metal object.

  Details of the mounting of the IC chip 6 as one element for realizing an RFID tag that can be manufactured at a low cost with a simple structure will be described with reference to FIGS. 5 and 6 show the RFID tag 8 before the IC chip 6 is mounted on the electrical connection portion 5 except for FIG. 6B. It is efficient to form the electrical connection portion 5 at the same time when the patch conductor portion 3 and the slot 4 are formed. However, the shape and size of the electrical connection portion 5 must match the number of connection terminals 7 and the characteristic impedance of the IC chip 6 to be mounted. . For example, in order to achieve impedance matching, in addition to fine adjustment of the shape of the slot 4, when there are two legs of the connection terminal 7, as shown in FIG. In the case where two electrical connection portions 5 having a width capable of matching the impedance of the connection terminal are formed and the number of the legs of the connection terminal 7 is four, as shown in FIG. Then, two electrical connection portions 5 having a width capable of impedance matching of the connection terminals are formed, two of the legs of the connection terminal 7 are connected, and the remaining two legs are connected to the dummy pad portion 20. As shown in FIGS. 5B and 6A, the dummy pad portion 20 is not electrically connected to the patch conductor portion 3 and the electrical connection portion 5. 6B is a perspective view of the IC chip 6 when the IC chip 6 is mounted. From FIG. 6B, the dummy pad portion 20 is independent not only electrically but also in radio waves. It can be seen that this is just a dummy pad portion for placing the remaining two legs of the connection terminal 7. It is efficient to perform the forming method simultaneously with the formation of the electrical connection portion 5, and as described above, a general printed board processing method can be used, and the specification of the IC chip 6 can be flexibly changed. Since it can respond, an RFID tag with a simple structure can be manufactured at low cost. Note that the number of dummy pad portions 20 is not limited to two, and may not be provided depending on the number of connection terminals 7 of the IC chip 6.

Embodiment 2. FIG.
A second embodiment of the present invention will be described with reference to FIGS. 7 is a configuration diagram of an RFID tag according to the second embodiment, FIG. 8 is a configuration diagram of the RFID tag according to the second embodiment, FIG. 9 is an enlarged view of a slot of the RFID tag according to the second embodiment, and FIG. ) Is before the IC chip is mounted, FIG. 9B is after the IC chip is mounted, FIG. 10 is a configuration diagram of the RFID tag according to the second embodiment, and in FIGS. An electrical length adjusting part 22 provided in a cutout shape at the end of the IC, a tapered slot formed so as to be wide in the opposite direction from the position where the IC chip 6 is disposed, and a patch conductor part 3 The slot is formed so as to have an angle with respect to the sides of the patch conductor 3 and radiates circularly polarized waves to the patch conductor portion 3 using a degenerate separation method. In the drawings, the same reference numerals denote the same or corresponding parts, and detailed descriptions thereof are omitted.

  The structure and operation of the RFID tag according to Embodiment 2 will be described with reference to FIGS. The second embodiment relates to the method of adjusting the electrical length of the RFID tag, the transmission and reception of circularly polarized waves by widening and degenerate separation, and the basic configuration and effects of the invention are the same as those of the first embodiment. FIG. 7 relates to a method for adjusting the electrical length of the RFID tag. The major difference from the RFID tag of FIG. 1 is that the electrical length is adjusted in the shape of a notch on the side of the patch conductor portion 3 as shown. This is the patch conductor portion 3 in which the portion 21 is formed. Since the electrical length adjusting portion 21 is provided at a position perpendicular to the slot 4, the effective electrical length of the patch conductor portion 3 is longer than the apparent length, and even if the operating frequency of the RFID system is fixed, Since the size of the patch conductor portion 3 can be reduced, the overall dimensions of the RFID tag 8 can be reduced. Since the length of the electrical length adjusting unit 21 can be changed if it is less than the length of the patch conductor portion 3, the overall size of the RFID tag 8 is increased to a business card size by adjusting the length and the degree of cutting. It is also possible to make the dimensions suitable for the installation target within a certain range. In addition to the adjustment of the electrical length adjusting unit 21, the thickness and relative dielectric constant of the dielectric substrate 1, the dimensions of the patch conductor unit 3, and the slot 4 are greatly related to the same as in the first embodiment. By adjusting and designing in accordance with the conditions, the dimensions of the RFID tag 8 and the desired radiation pattern and gain can be obtained. Further, it may be provided only on one side of the patch conductor portion 3.

  FIGS. 8 and 9 relate to the broadening of the RFID tag, and the slot 22 has a tapered shape whose width increases in the opposite direction from the position where the IC chip 6 is disposed. Compared with the slot 4 of FIG. 1, the opposite portion of the slot 4 is formed with a constant width in the opposite direction except for the electrical connection portion 5. Since the slot 22 has a tapered shape as described above, it is possible to increase the frequency of use of the RFID tag, and the band can be selected by adjusting the dimension in which the taper expands. Therefore, since the communication band of the RFID system can be widened, impedance matching is easy and not only deterioration of yield due to manufacturing errors can be reduced, but also impedance changes due to adhesion of water drops or dirt depending on the surrounding environment where the RFID tag 8 is installed. RFID tags having strong environmental resistance can be obtained. As shown in FIGS. 9A and 9B, the mounting of the IC chip is the same as the description of FIGS. 6A and 6B of the first embodiment, and thus the description thereof is omitted. The dummy pad portion 20 may not be necessary depending on the number of legs of the connection terminal 7 provided on the IC chip 6.

  FIG. 10 is related to circularly polarized wave transmission / reception by degenerate separation of the RFID tag. The major difference from the RFID tag of FIG. 1 is that the position of the slot 23 is relative to the patch conductor portion 3 as shown in FIG. Inclined. Compared to the slot 4 of FIG. 1, the slot 23 is formed with an inclination of about 45 ° around the IC chip 6 (the direction of inclination is determined by whether the radio wave to be transmitted / received is dextrorotatory or levorotatory). ). Since the slot 23 is provided at such a position, the slot 23 operates as a degenerate separation element (perturbation element) of the patch conductor portion 3. That is, an RFID tag capable of transmitting and receiving circularly polarized waves having a radiation pattern close to a radiation pattern in which the phase of the same radiation pattern is shifted by π / 2 on the radiation pattern of the RFID tag of FIG. 1 can be obtained. In addition, even when circularly polarized radio waves are used for radio communication of the RFID system, it is possible to cope. In general, the degenerate separation element is formed with an inclination of about 45 ° with respect to the patch conductor portion 3. However, in order to obtain a good radiation pattern due to the influence of the feeding point, the inclination angle is about 45 °. Instead, it is necessary to make fine adjustments. However, in the present invention, since the feeding point (IC chip 6) is provided at a position where the electric field becomes 0, the width of fine adjustment becomes relatively narrow, and the adjustment becomes easy. Further, the method of adjusting the electrical length of the RFID tag, the widening of the band, and the circularly polarized wave transmission / reception by degenerate separation in Embodiment 2 can be implemented in combination.

Embodiment 3 FIG.
A third embodiment of the present invention will be described with reference to FIGS. 11 is a configuration diagram of an RFID tag according to the third embodiment, FIG. 11A is a patch conductor surface of the RFID tag, FIG. 11B is a ground conductor surface (without an adhesive layer) of the RFID tag, and FIG. (C) is a grounding conductor surface of the RFID tag (with an adhesive layer), FIG. 12 is a configuration diagram of the RFID system according to Embodiment 3, and in FIGS. 11 and 12, 24 is an adhesive layer, 25 is It is an installation surface. In the drawings, the same reference numerals denote the same or corresponding parts, and detailed descriptions thereof are omitted. The RFID tag 8 in FIG. 11 is provided with an adhesive layer 24 on the surface of the ground conductor portion 2, and the adhesive layer 24 may be made of an adhesive, a double-sided tape, or the like. Be free. The installation surface 25 shown in FIG. 12 is a surface of an article or the like according to applications such as logistics management, warehouse management, equipment management, and car entrance / exit management regardless of metal or non-metal. The RFID tag 8 having the adhesive layer 24 attached to the installation surface 25 can perform wireless communication with the RFID reader / writer 9 because the patch conductor portion 3 has a smaller area than the dielectric substrate 1. This is because a change in characteristic impedance of the RFID tag 8 due to the influence when the installation position of the ground conductor or the RFID tag 8 is on the conductor is small because of the structure of the RFID tag 8 as described above. Therefore, it is possible to obtain a method of installing an RFID tag that can be installed even if the installation surface 25 is a metal or non-metal. The communication distance varies depending on the dimensions of the RFID tag 8 and the like.

It is a block diagram of the RFID tag by Embodiment 1 of this invention. 1 is a basic configuration diagram of an RFID system according to the present invention. It is an electric field diagram of the RFID tag of this invention. It is a characteristic impedance figure of the RFID tag by Embodiment 1 of this invention. It is an electrical connection part exposure figure of the RFID tag by Embodiment 1 of this invention. It is a slot enlarged view of the RFID tag by Embodiment 1 of this invention. It is a block diagram of the RFID tag by Embodiment 2 of this invention. It is a block diagram of the RFID tag by Embodiment 2 of this invention. It is a slot enlarged view of the RFID tag by Embodiment 2 of this invention. It is a block diagram of the RFID tag by Embodiment 2 of this invention. It is a block diagram of the RFID tag by Embodiment 3 of this invention. It is a block diagram of the RFID system by Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Dielectric substrate, 2 ... Ground conductor part, 3 ... Patch conductor part, 4 ... Slot, 5 ... Electrical connection part,
6 ... IC chip, 7 ... connection terminal, 8 ... RFID tag, 9 ... RFID reader / writer,
DESCRIPTION OF SYMBOLS 10 ... Antenna part, 11 ... Analog part, 12 ... A / D conversion part, 13 ... Power supply control part,
14 ... Memory unit, 15 ... Demodulation unit, 16 ... Control unit, 17 ... Modulation unit, 18 ... Digital unit,
19 ... D / A converter, 20 ... dummy pad, 21 ... electrical length adjuster,
22 ... slot (tapered), 23 ... slot (degenerate separation), 24 ... adhesive layer,
25 ... Installation surface

Claims (6)

A dielectric substrate, a ground conductor portion provided on one main surface of the dielectric substrate, a patch conductor portion provided on the other main surface of the dielectric substrate, in which a slot is formed, and an opposing portion of the slot An RFID tag comprising: an electrical connection portion extending inside; and an IC chip disposed inside the slot and connected to the electrical connection portion. The RFID tag according to claim 1, wherein the slot is formed in a central portion of the patch conductor portion and has an elongated shape. 2. The RFID tag according to claim 1, wherein the slot is formed to be wide in a reciprocal direction from a position where the IC chip is disposed. The RFID tag according to any one of claims 1 to 3, wherein the ground conductor portion is provided with an adhesive layer capable of adhering to a metal on the opposite side of the dielectric substrate. Conductor portion forming step for forming a ground conductor portion and a patch conductor portion on one main surface and another main surface of the dielectric substrate, a slot forming step for forming a slot inside the patch conductor portion, and formation of the slot At the same time, an electrical connection portion forming step for forming an electrical connection portion extending from the opposite portion of the slot to the inside thereof, and a connection for arranging the IC chip in the slot and connecting the IC chip to the electrical connection portion An RFID tag manufacturing method comprising the steps. A ground conductor provided on one main surface of the dielectric substrate, a patch conductor formed on the other main surface of the dielectric substrate, and formed with a slot, and an electrical connection portion extending inward from an opposing portion of the slot An RFID tag including an IC chip disposed inside the slot and connected to the electrical connection portion, wherein an adhesive layer capable of adhering to a metal is provided on the ground conductor portion on the side opposite to the dielectric substrate. An RFID tag installation method for installing the RFID tag on the metal.

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