JP5061712B2 - Non-contact IC tag manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a non-contact IC tag. More specifically, the present invention relates to a method for manufacturing two or more types of non-contact IC tags using different interposers for the same antenna element in a method for manufacturing a non-contact IC tag including a one-wavelength loop antenna or a half-wave dipole antenna.

  The non-contact IC tag is also referred to as an RFID (Radio Frequency Identification), and relates to a tag that includes an IC chip that holds information capable of identifying an individual and can read this information by wireless communication in a non-contact manner. Such IC tags are used in fields such as transportation and distribution, warehouses, factory process management, and handling of luggage.

In recent years, in addition to the conventional 13.56 MHz band or microwave band (2.45 GHz) non-contact IC tag, it has become possible to use the UHF band (952 M to 955 MHz) in Japan due to the revision of the law. Band non-contact IC tags are being put to practical use.
The UHF band IC tag can be collectively read from a long distance (3 to 5 meters) as compared to the electromagnetic induction type 13.56 MHz band non-contact IC tag. Further, the microwave band IC tag can communicate at a distance of 1 to 1.5 meters, and is expected to be widely used in applications that take advantage of these features in the future.

  Japan's frequency band where UHF band IC tags can be used is 2 MHz from 952 M to 954 MHz for the high output type and 3 MHz from 952 M to 955 MHz for the low output type due to the revision of the law in 2005. In the classification of radio waves, the UHF band indicates 300 M to 3 GHz, but in the case of a non-contact IC tag, it often refers to a tag using 860 M to 960 MHz. The IC tag using the 2.45 GHz band included in the above range is not usually called an UHF band IC tag but is a microwave band IC tag.

  By the way, since the non-contact IC tag is used by being attached to an article that is a dielectric material, when actually used, the non-contact IC tag has a resonance frequency designed on the assumption that radio waves are radiated to free space (vacuum). Thus, it is known that the resonance frequency at the time of attachment to the adherend changes somewhat (about 1 to 40 MHz). Since the change in the resonance frequency deteriorates the reading performance with respect to the reader / writer, the communication distance decreases as a result. In particular, when pasted on milk or liquor packs, plastic bottled liquids, radishes, rubber tires or other objects with high water content or dielectrics, the electromagnetic wave passing through the antenna element decreases and the induced power decreases. Is remarkable. In this case, there is a problem that the communication distance is extremely reduced, and communication with the reader / writer (R / W) cannot be secured.

Generally, the frequency characteristics of the non-contact IC tag label are determined by the stray capacitance of the IC chip or circuit and the external environment (such as the dielectric constant of the adherend as described above). The non-contact IC tag cannot be changed or replaced later. This is because the capacitance (C component) of the IC chip and the inductance (L component) of the antenna circuit can be predicted to some extent, but the state of the adherend cannot be predicted. Depending on the condition of the adherend, various non-contact IC tags having different resonance frequencies can be used, that is, many types of non-contact IC tag labels having different resonance frequencies can be manufactured and prepared, but they are attached to articles. At this time, it is troublesome and practically impossible to investigate the characteristics and select a suitable one from a variety of non-contact IC tag labels.
Further, even when substantially the same frequency is used, if the amount of memory mounted on the IC chip is insufficient in a specific application that requires a larger amount of information, another type of IC chip is used. You may need to use

  In view of this, the present invention provides a fixed antenna element, prepares multiple types of interposers suitable for the antenna element, and selects and uses an interposer suitable for an appropriate frequency and application according to the situation. It is intended. By doing so, a large number of antenna labels on which only planar antenna elements having a fixed shape are formed are prepared in advance, and an interposer that can obtain an optimum frequency according to the adherend and the situation of use is selected, or Even at the same frequency, an IC chip interposer suitable for the purpose can be selected and attached to the antenna label for use.

Regarding the non-contact IC tag interposer, there are prior arts such as Patent Document 1 and Patent Document 2. However, Patent Document 1 is only about the idea of bonding between two thin metal film antennas to complete an RFID, and describes that the frequency is adjusted by selecting and using the interposer itself. Not.
Patent Document 2 describes an RFID tag, and the RFID tag portion is considered to correspond to the interposer of the present application. However, since the RFID tag portion is intended to be used for different antenna patterns, it is different from being applied to antenna elements having the same shape and characteristics as in the present application. In addition, in the moving body identification system which consists of a dipole antenna, there exists patent document 3 as prior art which performs impedance adjustment, maintaining the directivity of an antenna, but the frequency adjustment method is different from this application.

JP 2000-311233 A JP 2007-52660 A JP 2004-104344 A

As described above, in UHF band non-contact IC tags, the frequency often varies depending on the dielectric constant of the adherend. In this case, it is not impossible to prepare many types of completed non-contact IC tags and select them according to the situation, but it is difficult as an actual problem. In addition, as in Patent Document 2, it is conceivable to prepare and use a plurality of types of antenna patterns for a certain RFID unit, but it is troublesome to prepare many types of antenna patterns in advance.
Therefore, in the present invention, a plurality of types of interposers capable of reducing the substrate area to a smaller size are prepared, and the optimum applicable interposer is selected and used for the same planar antenna element according to the situation of the adherend. It is intended to do.

One of the gist of the present invention for solving the above-mentioned problems consists of a non-contact tag IC chip having different characteristics and an impedance adjustment pattern between power supply terminal terminals of planar antenna elements having the same shape and characteristics formed on the base film. In a manufacturing method for obtaining two or more kinds of non-contact IC tags that can be mounted within a predetermined frequency of UHF band or microwave band by mounting an interposer, a circuit for connecting the IC chip and its circuit end as an impedance adjustment pattern A non-contact IC tag manufacturing method is characterized by using a circuit comprising a circuit for short-circuiting between them.

According to the second aspect of the present invention, an interposer having an impedance adjustment pattern different from an IC chip for a non-contact tag having the same characteristics is mounted between power supply terminal terminals of planar antenna elements having the same shape and characteristics formed on the base film. In a manufacturing method for obtaining two or more types of non-contact IC tags that can communicate within a predetermined frequency in the UHF band or microwave band, a circuit connecting the IC chip and a circuit end thereof are short-circuited as an impedance adjustment pattern. A non-contact IC tag manufacturing method characterized by using a circuit .

In the non-contact IC tag manufacturing method, the planar antenna element can be a single wavelength loop antenna or a half wavelength dipole antenna, and the predetermined frequency can be 952 MHz to 955 MHz. . It is also preferable that the peak of the antenna gain of the manufactured non-contact IC tag is within the predetermined frequency .

In the non-contact IC tag manufacturing method of the present invention, a large number of IC tag labels on which only the same planar antenna element is formed are prepared in advance, and are appropriately selected from various interposers according to the situation of the adherend. Since a suitable interposer can be selected and used, it is possible to eliminate waste that must be provided with a variety of completed IC tags.
Since the obtained non-contact IC tag is composed of the same planar antenna element, there is a feature that the directivity is not greatly changed even if the frequency characteristic is changed.

In the manufacturing method of claim 1, since an interposer comprising an IC chip for a non-contact tag with different characteristics and an impedance adjustment pattern is used, the selection range of the interposer is widened, and a non-contact IC tag suitable for the frequency and intended use can be obtained. It is done.
In the manufacturing method according to the second aspect, since the interposer including the IC chip for the non-contact tag and the impedance adjustment pattern having the same characteristics is used, restrictions on use due to the different IC chips can be reduced.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a plan view showing a planar antenna element of a non-contact IC tag, FIG. 2 is a diagram showing an example of an interposer used in the present invention, and FIG. 3 is a state diagram in which the interposer is mounted on a one-wavelength loop antenna. 4 and 5 are diagrams illustrating the frequency characteristics of the antenna input impedance, FIG. 6 is a diagram illustrating the antenna gain of the IC tag, and FIG. 7 is a diagram illustrating the return loss.
FIG. 8 is a state diagram in which an interposer is mounted on a half-wave dipole antenna, FIG. 9 is a diagram showing the antenna gain of the IC tag, and FIG. 10 is a diagram showing the return loss.

FIG. 1 is a plan view showing a planar antenna element of a non-contact IC tag. FIG. 1A shows a one-wavelength loop antenna, and FIG. 1B shows a half-wave dipole antenna.
In the case of a one-wavelength loop antenna, as shown in FIG. 1A, an antenna pattern 2 having an uneven shape bent on the surface of the label substrate 10 is formed. For the antenna label 1a, for example, a plastic substrate having a size that accommodates the antenna pattern 2 having a width H1 of 40 to 45 mm and a length L1 of 70 to 80 mm is used. Connection ends 2a and 2b to which an interposer is attached are formed at the end (feeding portion) of the antenna pattern 2. The total length of the antenna pattern 2 and the total length of the line including the IC chip of the interposer are formed to be approximately one wavelength of the communication frequency by the UHF band.

  The antenna pattern 2 is often formed by photoetching a base material obtained by laminating an aluminum foil or a copper foil to the label base material 10. A metal foil having a thickness of about 10 to 20 μm is used. The connection end portions 2a and 2b of the antenna pattern 2 need to have exposed metal surfaces, but other portions may be covered with a protective film. The label substrate 10 usually has an adhesive layer protected with a release paper on the opposite side of the antenna pattern 2 and is adhered to the adherend with the adhesive. However, it may be used without using an adhesive layer.

In the case of a half-wave dipole antenna, the left and right antenna patterns 3L and 3R are formed on the surface of the label substrate 10 as shown in FIG. 1B, and an interposer is attached to the end (feeding portion) of the antenna pattern 3. Connection end portions 3a and 3b are formed. In the case of FIG. 1B, the total length of the line is about 90 mm, but the operation is a half-wave dipole antenna. The manufacturing method and materials used for the antenna pattern 3 are the same as in the case of the one-wavelength loop antenna.
However, the shapes of the antenna patterns 2 and 3 are examples, and any pattern can be used as long as predetermined characteristics are obtained. The half-wave dipole antenna may also have a general line shape or a bent shape.

2A and 2B are diagrams illustrating an example of an interposer used in the present invention. FIG. 2A is a plan view, and FIG. 2B is a cross-sectional view taken along line AA in FIG.
The interposer 4 includes a non-contact IC tag IC chip 5 and an impedance adjustment pattern (also referred to as “matching circuit”) 6. The IC chip 5 includes a storage area for holding data and a circuit unit for controlling transmission and reception. Connection ends 4a and 4b attached to the antenna patterns 2 and 3 are provided at both ends of the lines 7a and 7b. The lines 7a and 7b and the impedance adjustment pattern 6 of the interposer 4 are often manufactured by photo-etching a metal foil laminated on the surface of the label base 20 like the antenna pattern.
The characteristics of the interposer 4 are changed depending on the shape and length of the IC chip 5 and the impedance adjustment pattern 6.

  As shown in the sectional view of FIG. 2B, the IC chip 5 is mounted between the lines 7a and 7b guided from the connection ends 4a and 4b. The IC chip 5 is fixed to the lines 7a and 7b with a conductive adhesive or the like. The IC chip 5, the lines 7a and 7b, and the connection ends 4a and 4b are preferably attached to the exposed connection ends 2a and 2b of the antenna label 1a so that they face the antenna label substrate 10 side. . In this case, the interposer label base material 20 is effective for protecting the IC chip 5 and the connection end portions 4a and 4b. An anisotropic conductive adhesive 8 is applied to the surface of the label substrate 20 including the surfaces of the connecting end portions 4a and 4b. Of course, the conductive adhesive 8 may be used for connection with ultrasonic waves or the like. The interposer 4 is usually in the form of a band in which a plurality of units are continuous, and can be continuously attached with a label applicator or the like.

  As described above, according to the present invention, the interposer 4 including the IC chip 5 for the non-contact tag having the different characteristics or the same characteristics and the impedance adjustment pattern 6 is mounted between the power feeding portion terminals of the planar antenna elements having the same shape and the same characteristics. An object of the present invention is to obtain two or more types of non-contact IC tags that can communicate within a predetermined frequency in the UHF band.

The UHF band is assumed to be 950 MHz to 956 MHz in Japan. Actually, the band of 952 MHz to 955 MHz is allocated, and the band of 950 MHz to 951 MHz and 955 MHz to 956 MHz uses the frequencies on both sides, respectively. It is considered as a free band to prevent interference. The ability to communicate within a predetermined frequency in the UHF band means that communication can be performed at a frequency within the range when the IC tag 1 is attached to the adherend.
Considering the change of about 1 to 40 MHz depending on the adherend as described above, a fluctuation of about 40 MHz (± 20 MHz centering on one IC tag) is required, and the destination in Japan and the United States or Europe In consideration of this difference, it is also necessary to be able to change within a range of about 140 MHz (± 70 MHz centered on one IC tag).
The UHF band is the above band in Japan, but is 902 MHz to 928 MHz in the United States, and 865 MHz to 868 MHz in Europe. Therefore, these bands are also predetermined frequencies in the UHF band. Of course, two or more types may be two types or more.

(Interposer for A chip)
3 shows a state in which the interposer 4 is attached to the connection ends 2a and 2b of the one-wavelength loop antenna 2 in FIG. 1A, and FIG. 3A shows a state in which the A-chip interposer 4A is attached. FIG. 3B shows the IC tag 1B in a state where the B chip interposer 4B is mounted. The antenna pattern 2 had a width H1 of 42.0 mm and a length L1 of 74.0 mm. The line width of the antenna is 1 mm. A 20 μm thick polyethylene terephthalate (PET) sheet was used for the label substrate 10 of the antenna label 1a, and an aluminum foil of 15 μm thickness was used for the metal foil. Interposers 4A and 4B were also made of the same material and the same thickness.

The A chip 5 of the IC tag 1A in FIG. 3A is a UHF band non-contact IC tag chip, and the optimum antenna input impedance is 30 + j110Ω (manufacturer nominal value).
The total line length of the antenna pattern 2 and the impedance adjustment pattern (matching circuit) 6 was about 330 mm including the bent portion of the antenna pattern 2.

  FIG. 4 is a diagram showing the frequency characteristics of the antenna input impedance of the IC tag 1A. It is a simulation calculation result by the finite element method (the same applies below). The solid line in FIG. 4 indicates the real part of the impedance, and the dotted line indicates the imaginary part. At 953 MHz, the input impedance is about 30 + j120Ω. For the optimum antenna input impedance value, a numerical value that does not cause a problem in practice is shown.

(B chip interposer)
The B chip 5 of the IC tag 1B in FIG. 3B is a UHF band non-contact IC tag chip, and the optimum antenna input impedance is 20 + j 200Ω (manufacturer nominal value).
The total line length of the antenna pattern 2 and the impedance adjustment pattern (matching circuit) 6 was about 339 mm including the bent portion of the antenna pattern 2. The interposer 4B is different from the interposer 4A in terms of the distance between the circuit connected to the chip 5 and the matching circuit 6 that short-circuits it, the connection position, and the like.

  FIG. 5 is a diagram showing the frequency characteristics of the antenna input impedance of the IC tag 1B. The solid line shows the real part of the impedance, and the dotted line shows the imaginary part of the impedance. At 953 MHz, it is about 19 + j208Ω. Also in this case, a numerical value that does not cause a problem in practice is shown for the optimum antenna input impedance value.

  FIG. 6 is a diagram showing the antenna gain of the IC tags 1A and 1B, and FIG. 7 is a diagram showing the return loss. In both figures, a solid line indicates an IC tag using an A chip, and a dotted line indicates an IC tag using a B chip. As shown in FIG. 6, it can be seen that both IC tags 1A and 1B have a gain peak near 953 MHz. As the gain value is higher, the communication distance as the IC tag becomes larger, so that it can be seen that the design is suitable as a tag for 953 MHz.

Further, as shown in FIG. 7, it can be seen that both IC tags 1A and 1B have a return loss valley in the vicinity of 953 MHz. As the return loss goes down on the graph, it means that the IC chip and the antenna are matched and the loss is small. Therefore, it can be seen that both the IC tags 1A and 1B are designed appropriately for 953 MHz.
From the above results, it can be seen that it is possible to manufacture an IC tag with substantially the same frequency characteristic of 953 MHz by mounting different interposers with different types of IC chips mounted on planar antenna elements having the same shape and characteristics. It was. Of course, it is obvious that IC tags 1 having different frequency characteristics within a predetermined frequency can be obtained.

(Interposer for C chip)
FIG. 8 shows a state in which a C-chip interposer is mounted on the half-wave dipole antenna 3, and FIG. 8A shows the connection ends 3 a and 3 b of the half-wave dipole antenna 3 in FIG. The IC tag 1C with the chip interposer 4C attached, and FIG. 8B shows the IC tag 1D with the C chip interposer 4D attached.
In FIG. 8 (see FIG. 1B), the antenna pattern 2 has a width H2 of 20 mm and a length L2 of 88 mm. A PET sheet having a thickness of 20 μm was used for the label substrate 10 of the antenna label 1a, and an aluminum foil having a thickness of 15 μm was used for the metal foil. Interposers 4C and 4D were also made of the same material and the same thickness.

  The IC chips 5 of the interposers 4C and 4D have the same antenna input impedance 30 + j120Ω, and only the impedance adjustment pattern 6 is different. The IC tag 1C in FIG. 8A is equipped with an interposer 4C designed for 915 MHz, and the IC tag 1B in FIG. 8B is equipped with an interposer 4C designed for 865 MHz. 915 MHz is designed for the United States (USA), and 865 MHz is designed for Europe.

FIG. 9 is a diagram showing the antenna gain of the IC tags 1C and 1D, and FIG. 10 is a diagram showing the return loss. In both figures, the solid line indicates the IC tag 1C (915 MHz) using the interposer 4C, and the dotted line indicates the IC tag 1D (865 MHz) using the interposer 4D.
As shown in FIG. 9, it can be seen that there is a gain peak at a lower frequency for 865 MHz than for 915 MHz. The higher the gain, the greater the communication distance as an IC tag, and it can be seen that the design is as desired.

As shown in FIG. 10, it can be seen that there is a valley in the vicinity of the planned frequency for both 915 MHz and 865 MHz. As the return loss goes down on the graph, the IC chip 5 and the antenna element are matched and the loss is small. Therefore, both design examples are designed appropriately for the planned frequency band. You can see that
From the above, it can be seen that even when IC chips having the same characteristics are mounted on the same antenna element, IC tags adapted to different frequencies can be manufactured by changing the shape of the impedance adjustment pattern 6 of the interposer.
The interposer 4D used in the IC tags 1C and 1D in FIG. 8 is different from the interposer 4C in terms of the distance between the circuit connected to the chip and the matching circuit short-circuiting it, the connection position, and the like. . The above difference has a great influence on the characteristics of the IC tag.

It is a top view which shows the planar antenna element of a non-contact IC tag. It is a figure which shows an example of the interposer used by this invention. It is a state figure which attached the interposer to the 1 wavelength loop antenna. It is a figure which shows the frequency characteristic of antenna input impedance. It is a figure which shows the frequency characteristic of antenna input impedance. It is a figure which shows the antenna gain of an IC tag. It is a figure which shows the return loss. FIG. 6 is a state diagram in which an interposer is attached to a half-wave dipole antenna. It is a figure which shows the antenna gain of an IC tag. It is a figure which shows the return loss.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 IC tag 1a, 1b Antenna label 2, 3 Antenna pattern, planar antenna element 4 Label-like interposer 4a, 4b Connection end 5 IC chip 6 Impedance adjustment pattern 7a, 7b Line 8 Anisotropic conductive adhesive 10 Label base material 20 Label substrate

Claims (6)

An interposer consisting of an IC chip for a non-contact tag with different characteristics and an impedance adjustment pattern is mounted between power supply terminals of planar antenna elements having the same shape and the same characteristics formed on the base film, and the UHF band or microwave band. In a manufacturing method for obtaining two or more kinds of non-contact IC tags capable of communicating within a predetermined frequency , an impedance adjustment pattern comprising a circuit to which the IC chip is connected and a circuit for short-circuiting between the circuit ends is used. A method for manufacturing a non-contact IC tag. An interposer consisting of an impedance adjustment pattern different from an IC chip for a non-contact tag having the same characteristics is mounted between power supply terminals of planar antenna elements having the same shape and characteristics formed on the base film, and the UHF band or microwave band. In a manufacturing method for obtaining two or more types of non-contact IC tags that can communicate within a predetermined frequency , an impedance adjustment pattern that includes a circuit that connects the IC chip and a circuit that short-circuits the circuit ends is used . A method of manufacturing a non-contact IC tag, which is characterized. 3. The method of manufacturing a non-contact IC tag according to claim 1, wherein the planar antenna element is a one-wavelength loop antenna. 3. The method of manufacturing a non-contact IC tag according to claim 1, wherein the planar antenna element is a half-wave dipole antenna. 3. The method for manufacturing a non-contact IC tag according to claim 1, wherein the predetermined frequency is 952 MHz to 955 MHz. 3. The method of manufacturing a non-contact IC tag according to claim 1, wherein the peak of the antenna gain of the manufactured non-contact IC tag is within the predetermined frequency.

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