JP5403353B2 - RFID tag manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing an RFID (Radio Frequency Identification) tag excellent in communication characteristics at low cost and excellent in productivity.

  In recent years, a non-contact type individual identification system using an RFID tag has been attracting attention as a system for managing the entire life cycle of goods in many business categories such as manufacturing, distribution, sales, security management, recycling, and the like. In particular, radio frequency type IC tags using UHF waves and microwaves are attracting attention due to the feature that an external antenna is attached to an IC chip and a communication distance of several meters is possible. System construction is underway for the purpose of product history management.

  RFID antennas are designed with various antennas depending on the application and operation method. The method of using an antenna in which an IC chip is electrically connected and another metal body formed through an insulating layer by an electrostatic coupling effect of a high-frequency current as an auxiliary antenna increases the communication distance, There is an effect of reducing radio wave interference when the RFID tag is in close contact. The shape of the auxiliary antenna is designed according to the purpose. In either case, the antenna and the auxiliary antenna connected to the IC chip partially overlap each other through the insulating layer to obtain the electrostatic coupling effect. Alignment is required.

  In order to realize a large quantity of merchandise distribution and article management by a non-contact type individual identification system using an RFID tag, it is necessary to attach an RFID tag to each of the merchandise. As an application for suppressing radio wave interference of a close RFID tag using an auxiliary antenna, management of a large amount of paper documents and files, electronic recording media such as CDs and DVDs, etc. can be considered, and the used RFID tags are inexpensive and expensive. Productivity is required.

  For this purpose, a method is considered in which an antenna connected to an IC chip and an auxiliary antenna are formed in advance on the front and back surfaces of a tape-like insulating layer (Patent Document 1).

JP 2008-117165 A

  However, in the above prior art, when the overlapping area of each antenna changes, the communication characteristics of the RFID also change accordingly. Therefore, in order to obtain stable communication characteristics, highly accurate alignment or one antenna It was necessary to keep the pattern large and to suppress the influence of positional deviation. FIG. 5 shows an example in which the antenna 9 and the auxiliary antenna 10 connected to the IC chip 1 are shifted and the overlapping area becomes small, and FIG. 6 shows a case in which the auxiliary antenna 10 is enlarged and the influence of positional deviation is suppressed. An example of this is shown in plan view.

  In order to obtain stable communication characteristics in the RFID tag using the auxiliary antenna as described above, the conventional example shown in FIG. 5 has a problem that it takes a long time to align the front and back surfaces of the insulating layer. In the conventional example shown in FIG. 2, there is a problem that the antenna cannot be formed with a narrow pitch, and it is difficult to produce an inexpensive and highly productive RFID tag.

  The present invention has been made in view of the above, and an object of the present invention is to provide an RFID tag production method capable of realizing low-cost and high productivity and obtaining stable communication characteristics.

The present invention relates to the following.
1. An IC chip for wireless communication, a first antenna electrically connected to the IC chip and provided with a matching circuit, and at least a part of the first antenna so that electrostatic coupling occurs with the first antenna. And a second antenna having a gap so as to include a region corresponding to the matching circuit of the first antenna, the RFID tag being formed in an overlapping manner via an insulating layer, An antenna tape formed by separately forming a plurality of the first antennas on one surface of an insulating layer and integrating the plurality of second antennas on the other surface of the insulating layer. Forming a plurality of IC chips at predetermined positions on the first antenna of the antenna tape to form an electrically connected RFID tag tape; and Method of manufacturing the RFID tag, characterized in that and a step of separating the FID tag.
2. 2. The RFID tag manufacturing method according to 1 above, wherein the second antenna is formed in two strips in the same direction as the longitudinal direction of the antenna tape, and the first antenna of the second antennas The length in the direction perpendicular to the longitudinal direction of the antenna tape in the non-overlapping region is longer than the length in the direction perpendicular to the longitudinal direction of the antenna tape in the region overlapping with the first antenna in the second antenna. A method for manufacturing an RFID tag, wherein
3. 3. The RFID tag manufacturing method according to 1 or 2 above, wherein an operating frequency of the IC chip is in a range of 850 MHz to 2.45 GHz.
4). 4. The method of manufacturing an RFID tag according to any one of 1 to 3, wherein the first antenna is a dipole antenna.
5. 5. The method of manufacturing an RFID tag according to any one of 1 to 4, wherein an arrangement pitch of the first antenna in the longitudinal direction of the antenna tape is 5 mm or less.
6). 6. The RFID tag manufacturing method according to any one of 1 to 5 above, wherein the length of the first antenna is 30 mm or less and the length of the second antenna is 60 mm or less. RFID tag manufacturing method.

  Since the RFID tag manufacturing method according to the present invention can easily align the first antenna and the second antenna, it is inexpensive and highly productive, and the overlapping area between the first antenna and the second antenna is high. Therefore, it is possible to realize an RFID tag capable of stabilizing communication characteristics affected by electrostatic coupling between both antennas.

It is a top view which shows the RFID tag tape which is the elongate state of the RFID tag of this invention. It is sectional drawing along A-A '. It is sectional drawing to which the IC chip mounting part vicinity was expanded. It is a top view which shows the individual state of the RFID tag of this invention. It is an example which shows the RFID tag tape which is the elongate state of the conventional RFID tag. It is an example which shows the RFID tag tape which is the elongate state of the conventional RFID tag.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In the RFID tag manufacturing method of the present invention, first, an IC chip is mounted on a long antenna tape on which a first antenna and a plurality of second antennas that are individually separated are formed. Joint. In the present invention, the first antenna refers to an antenna to which an IC chip is connected, and the second antenna is a so-called auxiliary antenna that is provided via the first antenna and an insulating layer and is not connected to the IC chip. Say what. The term “long” refers to a film-like substrate or the like in which one of the vertical and horizontal directions is twice or more longer than the other. For example, it is wound up like a tape wound around a winding core. The direction becomes longer than the width direction. An antenna tape is a tape formed by forming a first antenna on one surface of an insulating layer and a second antenna on the other surface so that the tape is wound around a winding core. The thing before mounting.

  FIG. 1 is a schematic plan view of the RFID tag tape 7 in which the IC chip 1 is mounted on the antenna tape 6, and FIG. 2 is a schematic cross-sectional view along A-A ′ of FIG. 1. The first antenna 2 on which the IC chip 1 is mounted is formed on the upper surface of the insulating layer 4 and on the lower surface of the insulating layer 4 in two strips along the longitudinal direction of the insulating layer 4 (that is, the longitudinal direction of the antenna tape 6). The second antenna 3 is formed. The first antenna 2 is formed individually for each RFID tag, and the second antenna is formed integrally with a plurality of RFID tags. A gap G3 is provided between the two second antennas 3 formed in a band shape. Here, the RFID tag tape 7 refers to a state after the IC chip 1 is mounted at a predetermined position of the antenna tape 6, that is, a state before being separated into individual RFID tags to be in a single piece state. That is, it is a long state in which individual RFID tags are continuously connected.

  The first antenna 2 and the second antenna 3 overlap with each other through the insulating layer 4 at portions H1 and H2 in FIG. When the electric coupling occurs, the second antenna 3 functions as an auxiliary antenna for the first antenna 2.

  FIG. 3 is a schematic sectional view showing an example of the structure in the vicinity of the IC chip 1 mounting portion. The IC chip 1 is provided with a plurality of external electrodes 1A, and each external electrode 1A is electrically connected to a predetermined position of the first antenna 2 in a flip chip structure. A sealing resin 5 is filled between the IC chip 1 and the first antenna 2 and the insulating layer 4 to increase the bonding strength between the IC chip 1 and the first antenna 2 and the insulating layer 4. The electrical connection between the IC chip 1 and the first antenna 2 is not limited to the flip chip structure, but is preferable in that the RFID tag can be thinned.

  In the long RFID tag tape 7 formed as described above, the gap portion I of the first antenna is cut as shown by BB ′ and CC ′ in FIG. The shape after the separation is shown in FIG. Separation into individual RFID tags 8 can be performed, for example, by cutting with a cutting blade or the like every time the antenna tape 6 is unwound by a predetermined length. The manufacturing method of the RFID tag 8 according to the present invention is such that the IC chip 1 is attached to a long antenna tape 6 in which a first antenna 2 that is individually separated and a second antenna 3 in which a plurality of antennas are integrated are formed. After the RFID tag tape 7 is formed by mounting and electrical joining, the first antenna 2 and the second antenna 3 can be easily aligned by separating and cutting into individual RFID tags 8. In addition, since the overlapping area of the first antenna 2 and the second antenna 3 can be made constant, the communication characteristics affected by the electrostatic coupling between the two antennas 2 and 3 can be stabilized, that is, inexpensive. Thus, the RFID tag 8 with high productivity and excellent communication characteristics can be realized.

  Regarding the operating frequency of the IC chip, since the RFID tag obtained in the present invention uses the electrostatic coupling effect, it is preferable to be in the microwave band in the range of 850 MHz to 2.45 GHz.

  The first antenna structure is preferably a linear dipole type. By using a linear dipole antenna, the arrangement pitch in the longitudinal direction of the antenna tape can be reduced. For example, by using an IC chip of about 0.5 mm square and setting the width of the first antenna to about 3 mm, it is possible to make the arrangement pitch 5 mm or less, which is an effect of the present invention at low cost and productivity. It is suitable for the manufacture of high RFID. If the width of the first antenna is about 1.5 mm, the arrangement pitch can be 3 mm or less, which is more preferable.

  Regarding the length of the first antenna and the second antenna, for example, when the operating frequency of the IC chip is 2.45 GHz, the length of the first antenna is 30 mm or less, and the length of the second antenna is 60 mm. Assuming the following, the communication characteristics of the RFID tag obtained according to the present invention are not much different from those of a general half-wave dipole antenna, and generally occur when a plurality of RFID tags are in close contact with each other. This is preferable because it is possible to suppress deterioration in communication characteristics due to mutual interference between tags.

  EXAMPLES Hereinafter, although the suitable Example of this invention is described, this invention is not limited to a following example.

  First, a long base made of an insulating film made of polyethylene naphthalate (PEN) with a thickness of 25 μm and bonded with a hard aluminum foil with a thickness of 20 μm on the front surface and a hard aluminum foil with a thickness of 30 μm on the back surface. Materials were prepared.

  Next, after forming an etching resist on the front and back aluminum foil surfaces by gravure printing, etching is performed with a ferric chloride aqueous solution, and the surface has a T-shaped matching circuit on the IC chip mounting portion. Two strip-shaped second antennas were formed so as to have a gap in the center region in the width direction (perpendicular to the longitudinal direction) of the long base material on the back surface.

  Detailed dimensions of the first and second antennas will be described with reference to FIGS. In this embodiment, the width D of the first antenna 2 is 1.5 mm, the length E is 25 mm, and the arrangement pitch F is 2.4 mm. Further, the length G1 and G2 of each of the strip antennas of the second antenna 3 is 16 mm, the gap G3 is 13 mm, and the overall length G of the second antenna 3 is 45 mm. The overlapping lengths H1 and H2 of the first antenna 2 and the second antenna 3 are 6 mm, and the entire width of the antenna tape 6 is 70 mm.

  Next, Au bumps serving as external terminals of an IC chip for RFID having an operating frequency of 2.45 GHz (Muchip, manufactured by Renesas Technology Corp., and Muchip is a registered trademark of Hitachi, Ltd.) are connected to the T-shape of the first antenna. Alignment was performed with a flip chip structure at a predetermined position of the matching circuit portion of the mold, and bonding was performed by applying ultrasonic waves. The gap between the IC chip and the first antenna was filled with a sealing resin (RC091, manufactured by Hitachi Chemical Co., Ltd.), and heat cured at 120 ° C. for 2 hours. Through the above process, 16,000 IC chips were mounted on an antenna tape of about 40 m to form an RFID tag tape, and then wound around a paper core.

  Next, the RFID tag tape wound around the paper core is unwound little by little, and the gap portion of the first antenna is sequentially cut with a cutting blade, and 16,000 RFID tags having a long side of 70 mm and a short side of 2.4 mm are obtained. Obtained.

  Since the RFID tag described in this embodiment includes a small first antenna and a second antenna having an auxiliary antenna function due to the electrostatic coupling effect, a plurality of RFID tags are in close contact with each other at an interval of about 3 mm. However, radio wave interference of the RFID tag can be suppressed. Because the area of the overlapping portion of the first antenna and the second antenna can be kept constant, the variation in communication characteristics is small, and the length of the short side can be reduced to 2.4 mm. Productivity was realized.

  The RFID tag produced in this embodiment can be used for management of paper documents, files, electronic recording media such as CDs and DVDs.

1: IC chip 1A: external electrode 2: first antenna 3: second antenna 4: insulating layer 5: sealing resin 6: antenna tape 7: RFID tag tape 8: RFID tag 9: antenna on which an IC chip is mounted 10: Auxiliary antenna D: Width of first antenna E: Length of first antenna F: Arrangement pitch of first antenna G: Length of second antenna G1, G2: Band-shaped second antenna Length G3: Gap H1 between the second antennas in the band shape, H2: Overlapping length between the first antenna and the second antenna I: Gap between the first antennas

Claims (6)

An IC chip for wireless communication, a first antenna electrically connected to the IC chip and provided with a matching circuit, and a portion of the first antenna so that electrostatic coupling occurs with the first antenna. A method of manufacturing an RFID tag having a second antenna that is formed so as to overlap with an insulating layer and includes a gap so as to include a region corresponding to the matching circuit of the first antenna ,
A plurality of the first antennas are separately formed on one surface of the long insulating layer, and a plurality of the second antennas are integrally formed on the other surface of the insulating layer. Forming an antenna tape;
Mounting a plurality of IC chips at predetermined positions on the first antenna of the antenna tape to form an electrically connected RFID tag tape;
Separating the RFID tag tape into individual RFID tags;
The manufacturing method of the RFID tag characterized by having. It is a manufacturing method of the RFID tag according to claim 1,
The second antenna is formed in two strips in the same direction as the longitudinal direction of the antenna tape, and the second antenna has a region perpendicular to the longitudinal direction of the antenna tape in a region that does not overlap with the first antenna. A method for manufacturing an RFID tag, wherein a length of the region of the second antenna that overlaps with the first antenna is longer than a length in a direction perpendicular to a longitudinal direction of the antenna tape . An RFID tag manufacturing method according to claim 1 or 2,
The RFID tag manufacturing method, wherein an operating frequency of the IC chip is in a range of 850 MHz to 2.45 GHz. An RFID tag manufacturing method according to any one of claims 1 to 3,
The RFID tag manufacturing method, wherein the first antenna is a dipole antenna. An RFID tag manufacturing method according to any one of claims 1 to 4,
The RFID tag manufacturing method, wherein an arrangement pitch of the antenna tape in the longitudinal direction of the first antenna is 5 mm or less. An RFID tag manufacturing method according to any one of claims 1 to 5,
An RFID tag manufacturing method, wherein the length of the first antenna is 30 mm or less and the length of the second antenna is 60 mm or less.

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