RF tag

Abstract

To provide an RF tag which has excellent communication stability even if it has a hole on an antenna part.SOLUTION: An RF tag 100 comprises: a base material 110; an antenna part 120 which has a substantially rectangular conductive region 120a disposed on the base material 110; a semiconductor device 130, disposed on the base material 110, which is electrically bonded to the antenna part 120; a collector part 140 which electrically bonds the antenna part 120 to the semiconductor device 130; and a covering material 150 which covers the antenna part 120, the semiconductor device 130, and the collector part 140. The antenna part 120 has one or more non-conductive regions 120b. In a width direction D1 of the antenna part 120, a total width occupied by the non-conductive regions 120b is less than 90%. A shortest distance between the collector part 140 and the non-conductive regions 120b is equal to or higher than 0.30% of a length of the waves outputted by the antenna part 120.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to an RF tag. [Background technology]

[0002] Conventionally, RF (Radio Frequency) tags equipped with IC chips and antennas have been used for product management in retail stores. These RF tags are attached to products and a dedicated data reading and writing device is used to read and write product data, allowing for product entry / exit management, inventory management, rental management, etc., and because RF tags are equipped with IC chips, they can manage a wealth of information together with the product, such as not only the product code but also the arrival date, person in charge, etc.

[0003] From the viewpoint of traceability and efficient inventory management, UHF RF tags are rapidly becoming more commonplace, being attached to a variety of products such as food, miscellaneous goods, clothing, and metal parts. RF tags generally use metal materials with high electrical conductivity, so the radio wave radiation efficiency is nearly 100%. For this reason, for normal RF tags, it is necessary to design an antenna shape that resonates in the UHF band according to the size and dielectric constant of the affixed material so that a long communication distance can be achieved at UHF frequencies.

[0004] A technology has also been proposed in which such RF tags are formed with a conductive pattern in which the antenna portion is miniaturized, thereby improving the invisibility of the conductive pattern (see, for example, Patent Document 1). With this technology, the antenna portion, which occupies most of the area of ​​the RF tag, can be made transparent, preventing the affixing of the RF tag from obscuring the information on the product package. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP2016-105624 Public Relations Summary of the Invention [Problem to be solved by the invention]

[0006] By the way, manufacturers of clothing, leather and bags, in particular, are hoping to make holes in the antenna of the RF tag mounted on the tag of the product in order to avoid damaging the brand image.However, since general UHF band RF tags are made of metal material several millimeters wide and are designed to fit the material to which they are attached, there is a problem that the antenna part is damaged or broken by the hole for passing the string through, which significantly reduces the communication distance.

[0007] The present invention has been made in consideration of the above problems, and has an object to provide an RF tag that has excellent communication stability even if the antenna portion has a hole. [Means for solving the problem]

[0008] That is, the present invention is as follows. [1] A substrate; an antenna portion having a substantially rectangular conductive region disposed on the base material; a semiconductor element disposed on the base material and electrically connected to the antenna portion; a current collecting portion that electrically connects the antenna portion and the semiconductor element; a covering material that covers the antenna portion, the semiconductor element, and the current collecting portion; The antenna portion has one or more non-conductive regions, In the width direction of the antenna portion, a total width W occupied by the non-conductive regions is less than 90%; The shortest distance L between the current collecting portion and the non-conducting region is 0.30% or more of the wavelength λ output by the antenna portion. RF tag. [2] In the non-conducting region closest to the current collecting portion, the ratio (W' / L) of the maximum width W' to the shortest distance L is 70 or less; The RF tag described in [1]. [3] The conductive region contains at least one metal selected from the group consisting of copper, aluminum, silver, gold, and zinc. The RF tag described in [1]. [4] The conductive region is formed of a substantially rectangular metal film or a thin metal wire extending in a substantially rectangular shape. The RF tag described in [1]. [5] The line width of the metal thin wire is 0.25 μm or more and 200 μm or less. The RF tag described in [4]. [6] The pitch interval of the metal thin wires is 1.0 μm or more and 300 μm or less. The RF tag described in [4]. [7] A through hole is provided that passes through the coating material to the substrate, The through hole is formed so as to penetrate at least a part of the non-conductive region. The RF tag described in [1]. Effect of the Invention

[0009] According to the present invention, it is possible to provide an RF tag that has excellent communication stability even if the antenna portion has a hole. [Brief description of the drawings]

[0010] [Figure 1A] FIG. 1 is a perspective view illustrating an embodiment of an RF tag 100 according to the present invention. [Figure 1B] FIG. 1 is a perspective view illustrating an embodiment of an RF tag 100 according to the present invention. [Diagram 2] FIG. 1B is an enlarged view of region S in FIG. 1A. [Figure 3A] 2 is a plan view showing an embodiment of an antenna unit 120. FIG. [Figure 3B] 2 is a plan view showing an embodiment of an antenna unit 120. FIG. [Figure 3C] 2 is a plan view showing an embodiment of an antenna unit 120. FIG. [Figure 4] 11 is a diagram showing the relationship between non-conductive areas and communication stability in an example and a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Below, we will explain in detail the embodiment of the present invention (hereinafter referred to as the "present embodiment"). However, the present invention is not limited to this embodiment, and various modifications are possible without departing from the gist of the present invention.

[0012] 1. RF tags The RF tag 100 of this embodiment comprises a substrate 110, an antenna section 120 having a substantially rectangular conductive region 120a arranged on the substrate 110, a semiconductor element 130 arranged on the substrate 110 and electrically connected to the antenna section 120, a current collecting section 140 electrically connecting the antenna section 120 and the semiconductor element 130, and a covering material 150 covering the antenna section 120, the semiconductor element 130, and the current collecting section 140, wherein the antenna section 120 has one or more non-conductive regions 120b, and in a width direction D1 of the antenna section 120, a total width W occupied by the non-conductive regions 120b is less than 90%, and a shortest distance L between the current collecting section 140 and the non-conductive region 120b is 0.30% or more of the wavelength λ output by the antenna section 120.

[0013] In this embodiment, "RF tag" is an abbreviation for "Radio Frequency tag" and refers to a tag that has an antenna and is capable of transmitting and receiving a specific frequency. Note that RF tags may also be called other names, such as electronic tags, IC tags, wireless tags, and RF tags. In this embodiment, "RF tag" refers to a tag that is used together with a corresponding reader and is capable of transmitting or receiving data contactlessly between the reader. Such contactless transmission or transmission is preferably performed by radio waves. Note that the reader may also function as a writer (write).

[0014] In this embodiment, an RF tag 100 is shown which is a passive tag that does not have a built-in battery and operates using radio waves received from a reader / writer as its energy source. However, the RF tag 100 of this embodiment may also be an active tag which further has a built-in battery (not shown) and uses the power as a power source for transmission / reception and for the internal circuitry, or a semi-passive tag which has a built-in sensor and a battery as a power source for the sensor.

[0015] 1A and 1B are perspective views showing one embodiment of the RF tag 100 of this embodiment. Fig. 1A shows an embodiment in which the antenna section 120 is made of a mesh of thin metal wires, and Fig. 1B shows an embodiment in which the antenna section 120 is made of a metal plate. Fig. 2 shows an enlarged view of an area S in Fig. 1A. Figs. 3A to 3C show plan views showing embodiments of the antenna section 120. Hereinafter, the RF tag 100 of this embodiment will be described with reference to these figures.

[0016] 1.1. Base material The material of the substrate 110 is not particularly limited, but examples thereof include inorganic substrates such as glass; and organic substrates such as acrylic acid ester, methacrylic acid ester, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, nylon, aromatic polyamide, polyether ether ketone, polysulfone, polyethersulfone, polyimide, and polyetherimide.

[0017] Among these, polyethylene terephthalate, polyimide, or polyethylene naphthalate is preferable. By using polyethylene terephthalate, the productivity (cost reduction effect) for manufacturing the RF tag 100 is more excellent, and the adhesion between the base material 110 and the antenna unit 120 tends to be more improved. Furthermore, by using polyimide, the heat resistance of the RF tag 100 tends to be more improved. Furthermore, by using polyethylene naphthalate, the adhesion between the base material 110 and the antenna unit 120 tends to be more excellent.

[0018] The substrate 110 may be made of one material or may be a laminate of two or more materials. When the substrate 110 is a multilayer body in which two or more materials are laminated, the substrate 110 may be a laminate of organic substrates or inorganic substrates, or a laminate of an organic substrate and an inorganic substrate.

[0019] The substrate 110 may be transparent. In this embodiment, "transparent" means that the visible light transmittance is 80% or more. The visible light transmittance of the substrate 110 is preferably 90% or more, and more preferably 95% or more. The upper limit of the visible light transmittance of the substrate 110 is not particularly limited, but may be 100% or less. The visible light transmittance can be measured in accordance with JIS K 7361-1:1997.

[0020] The thickness of the substrate 110 is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 250 μm or less, and even more preferably 25 μm or more and 150 μm or less.

[0021] 1.2.Antenna section The antenna unit 120 has a substantially rectangular conductive region 120a disposed on the substrate 110, and one or more non-conductive regions 120b. The conductive region 120a is a region that is electrically connected to the current collecting unit 140. On the other hand, the non-conductive region 120b is a region where the conductive material that constitutes the antenna unit 120 is not present, and is a region that is not electrically connected to the current collecting unit 140.

[0022] The antenna unit 120 may be made of a mesh of fine metal wires as shown in Fig. 1A, or may be made of a metal plate as shown in Fig. 1B. By making the antenna unit 120 of a mesh of fine metal wires, the visibility of the antenna is reduced and the transparency of the antenna unit is further improved. This allows the RF tag 100 to be attached without damaging the appearance of the product. Furthermore, by making the antenna unit 120 of a metal plate, there is a tendency for communication stability to be maintained even if the antenna unit has a hole.

[0023] 3A to 3C are plan views showing aspects of the antenna unit 120. As shown in Fig. 3A, the non-conductive region 120b may be a hole of any size and shape, as shown in Fig. 3B, the non-conductive region 120b may be in the shape of any letter, number, symbol, pattern, or the like, or as shown in Fig. 3C, the non-conductive region 120b may be a large notch or the like formed in the conductive region 120a.

[0024] The non-conductive area 120b may be discontinuous or continuous. For example, as shown in Fig. 3A, by arranging discontinuous holes irregularly, the non-conductive area 120b can be used as a unique ID like Braille. Also, as shown in Fig. 3B, any continuous letters, numbers, symbols, etc. may be written.

[0025] In the width direction D1 of the antenna unit 120, the total width W occupied by the non-conductive regions 120b is less than 90%. Here, the "total width W occupied by the non-conductive regions 120b in the width direction D1" is filled at any position in the longitudinal direction D2. Specifically, as shown in FIG. 3A, when there is one non-conductive region 120b1 in the width direction D1, it means the width W1 of the non-conductive region 120b1, and when there are multiple non-conductive regions 120b2, 120b3 in the width direction D1, it means the total width (W2+W3) of the widths of the multiple non-conductive regions 120b2, 120b3. By keeping the total width W within the above range, the stability of communication is maintained even if the antenna unit has a hole.

[0026] The width direction D1 may be a direction parallel to the short sides of the substantially rectangular conductive region 120a, and the length direction D2 may be a direction parallel to the long sides of the substantially rectangular conductive region 120a.

[0027] The total width W may be 1% or more and 85% or less, 5% or more and 85% or less, 10% or more and 80% or less, 15% or more and 75% or less, 20% or more and 70% or less, 25% or more and 65% or less, or 30% or more and 60% or less.

[0028] Furthermore, the shortest distance L between the current collecting portion 140 and the non-conductive region 120b is 0.30% or more of the wavelength λ output by the antenna portion 120. Here, "the shortest distance L between the current collecting portion 140 and the non-conductive region 120b" means the shortest distance between the boundary between the current collecting portion 140 and the non-conductive region 120b as shown in Fig. 3A, and in the case where there are multiple non-conductive regions 120b, means the shortest distance L between the current collecting portion 140 and the boundary of the non-conductive region 120b4 that is closest to the current collecting portion 140. By keeping the shortest distance L within the above range, the stability of communication is maintained even if the antenna portion has a hole.

[0029] The wavelength λ is not particularly limited, but for example, assuming the UHF band (920 MHz), it is 326 mm. The range of such a wavelength λ is, for example, 860 to 960 MHz.

[0030] The shortest distance L is 0.40% or more, 0.50% or more, 0.75% or more, 1.00% or more, 1.25% or more, 1.50% or more, 2.00% or more, or 3.00% or more of the wavelength λ output by the antenna unit 120. There is no particular limit to the upper limit of the shortest distance L, but considering that the non-conductive region 120b is formed in the conductive region 120a, the length from the current collecting unit 140 to the end of the conductive region 120a becomes the upper limit of the shortest distance L.

[0031] Furthermore, there is a tendency that the stability of communication is more easily maintained even if the antenna portion has a hole if there is no large non-conductive region 120b near the current collecting portion 140. From this viewpoint, in the non-conductive region 120b closest to the current collecting portion 140, the ratio (W' / L) of the maximum width W' to the shortest distance L is preferably 70 or less, and may be 1 to 65, 2 to 60, 3 to 55, 4 to 50, 5 to 45, 6 to 40, or 7 to 35. By having the ratio (W' / L) of 70 or less, the stability of communication is maintained even if the antenna portion has a hole.

[0032] In addition, here, "the maximum width W' in the nearest non-conductive region 120b" refers to, for example, the diameter of the non-conductive region 120b4 in Fig. 3A. In other words, the width W' can be determined by identifying one nearest non-conductive region 120b and determining the maximum width of that region in the width direction D1.

[0033] The metal constituting the conductive region 120a of the antenna portion 120 is not particularly limited, but may be, for example, at least one metal selected from the group consisting of copper, aluminum, silver, gold, and zinc. Among these, silver or copper is preferable, and copper is more preferable.

[0034] The length of the width direction D1 of the conductive region 120a is preferably 5 mm to 30 mm, 6 mm to 26 mm, 7 mm to 22 mm, or 8 mm to 18 mm. The length of the longitudinal direction D2 of the conductive region 120a is preferably 25 mm to 75 mm, 30 mm to 70 mm, 35 mm to 65 mm, 40 mm to 60 mm, or 45 mm to 65 mm.

[0035] Here, the length in the width direction D1 and the length in the longitudinal direction D2 of the conductive region 120a may both be the maximum length in the width direction D1 and the maximum length in the longitudinal direction D2 of the outer shape of one conductive region 120a.

[0036] By having the length in the width direction D1 and the length in the longitudinal direction D2 of the conductive region 120a fall within the above ranges, the stability of communication is maintained even if the antenna portion has a hole.

[0037] The conductive region 120a may be formed of a metal film having a substantially rectangular shape as shown in FIG. 1B, or may be formed of a thin metal wire extending in a substantially rectangular shape as shown in FIG. 1A. Of these, it is preferable that the conductive region 120a be formed of a thin metal wire extending in a substantially rectangular shape. This creates a large number of branching points in the antenna section 120, making it easier to maintain conduction even if the antenna section is damaged. Therefore, even if the antenna section has a hole, the stability of communication tends to be maintained.

[0038] Fig. 2 shows an enlarged view of region S in Fig. 1A. As shown in Fig. 2, when conductive region 120a is a thin metal wire extending in a substantially rectangular shape, antenna section 120 has antenna pattern 121 and an opening 122. The outer edge shape of antenna pattern 121 is designed so that antenna section 120 responds to a predetermined frequency. The thin conductive wires constituting antenna pattern 121 are electrically conductive to each other within the region of antenna section 120.

[0039] The antenna pattern 121 is, for example, a grid made of thin conductive wires. The unit shape of the grid is not particularly limited, but may be, for example, a triangle; a quadrangle such as a square, a rectangle, or a rhombus; a pentagon; a hexagon; or a combination of a plurality of polygons. FIG. 2 shows a grid whose unit shape is a quadrangle.

[0040] The line width W4 of the thin metal wire is preferably 0.25 μm to 200 μm, 0.25 μm to 100 μm, 0.5 μm to 50 μm, 0.5 μm to 30 μm, or 0.5 μm to 15 μm. By setting the line width W4 of the thin metal wire within this range, the visibility of the thin metal wire decreases, the visibility of the antenna unit 120 can be decreased, and the stability of communication tends to be maintained even if the antenna unit has a hole.

[0041] The pitch interval P of the metal thin wires is preferably 1.0 μm or more and 500 μm or less, 1.0 μm or more and 300 μm or less, 1.0 μm or more and 300 μm or less, 10 μm or more and 250 μm or less, or 50 μm or more and 200 μm or less. When the pitch interval P is 1.0 μm or more, the transmittance tends to be further improved. Also, when the pitch interval P is 1.0 μm or more, the stability of communication tends to be maintained even if the antenna part has a hole.

[0042] 2, when the conductive region 120a is formed of thin metal wires extending in a substantially rectangular shape, the conductive region 120a has an opening 122. However, the opening 122 in the conductive region 120a does not correspond to the non-conductive region 120b of this embodiment. From this point of view, the minimum area of ​​each non-conductive region 120b is larger than the maximum area of ​​the opening 122. Specifically, the maximum area of ​​the opening 122 is preferably 0.36 mm 2 Less than 0.25mm 2 Less than 0.16mm 2 Less than 0.09mm 2 Less than 0.04mm 2 The minimum area of ​​each non-conducting region 120b is preferably 0.50 mm 2 Above 1.00mm 2 Above 2.00mm 2 Above 3.00mm 2 That's all.

[0043] In addition, when the antenna pattern 121 is a square grid pattern, the aperture ratio can be made 99% by setting the pitch P1 of the antenna pattern 121 with a line width of 1 μm to 200 μm. Note that the pitch P1 means the sum of the line width W4 and the distance between the conductive thin lines.

[0044] The thickness H1 of the thin metal wire constituting the antenna pattern 121 is preferably 10 nm or more and 750 nm or less, 25 nm or more and 500 nm or less, or 50 nm or more and 250 nm or less. When the thickness H1 of the thin metal wire is 10 nm or more, the stability of communication tends to be maintained even if the antenna part has a hole. On the other hand, when the thickness H1 of the thin metal wire is 750 nm or less, the transmittance tends to be further improved at a wide viewing angle.

[0045] The visible light transmittance T1 of the antenna unit 120 is preferably 75% or more and 99.9% or less, and more preferably 80% or more and 99.5% or less. The visible light transmittance can be measured by calculating the transmittance in the visible light range (360 to 830 nm) in accordance with the total light transmittance of JIS K 7361-1:1997. The visible light transmittance T1 of the antenna unit 120 tends to be further improved by reducing the line width of the antenna pattern or improving the pitch interval P.

[0046] 1.3.Semiconductor Devices The semiconductor element 130 is disposed on the substrate 110 and electrically joined to the antenna section 120. The semiconductor element 130 is not particularly limited, but may be an integrated circuit such as a memory element. A known semiconductor element 130 may be used depending on the application of the RF tag 100. The configuration of the semiconductor element 130 is not particularly limited, but may have functional sections such as a memory section, a power supply rectifier section, a receiver section, a controller section, and a transmitter section.

[0047] 1.4. Current collector The current collecting section 140 electrically joins the antenna section 120 and the semiconductor element 130. The current collecting section 140 is electrically connected to the antenna section 120, and is a section that collects, toward the semiconductor element 130, electricity generated by the antenna section 120 in response to radio waves of a predetermined frequency.

[0048] 1.5.Coating material The covering material 150 covers the antenna unit 120, the semiconductor element 130, and the current collecting unit 140. The covering material 150 is not particularly limited, but examples of the covering material that can be used include thermosetting resins such as phenolic resin, thermosetting epoxy resin, thermosetting polyimide, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyurethane, diallyl phthalate resin, and silicone resin; UV-curable resins such as urethane acrylate, acrylic resin acrylate, epoxy acrylate, silicone acrylate, and UV-curable epoxy resin; and commercially available coating agents.

[0049] Furthermore, a substrate can be attached via an adhesive using the curable resin or a commercially available acrylic resin, and the resulting substrate can be used as the covering material 150. Here, the substrate is not particularly limited, and examples thereof include inorganic substrates such as glass, and organic substrates such as acrylic acid esters, methacrylic acid esters, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, nylon, aromatic polyamide, polyether ether ketone, polysulfone, polyether sulfone, polyimide, and polyetherimide.

[0050] By using such a covering material 150, the covering material 150 tends to have transparency and exhibit good adhesion to the antenna section 120 and the base material 110.

[0051] 1.6.Through holes The RF tag 100 of this embodiment has a through-hole (not shown) that penetrates from the covering material 150 to the base material 110, and the through-hole may be formed so as to penetrate at least a part of the non-conductive region 120b. Such a through-hole can be used as a hole for passing a string of a product tag through, for example.

[0052] By providing the non-conductive region 120b as in this embodiment, a through hole can be formed in that portion using a hole puncher or the like. On the other hand, in the case where the non-conductive region 120b does not exist as in the case of conventional RF tags, a through hole is formed in the conductive region 120a using a hole puncher or the like, but forming a through hole in the antenna portion, which is a thin metal wire or metal plate, may damage the RF tag or cause communication to become unstable due to damage to the antenna portion 120. In contrast, by forming a through hole in the non-conductive region 120b formed in advance using a hole puncher or the like, it is possible to avoid damage to the RF tag or damage to the antenna portion 120.

[0053] 2. Manufacturing method of RF tags The manufacturing method of the RF tag 100 of this embodiment may include a film formation step of forming a precursor thin film on the substrate 110 using a plate by plate printing, a heating step of baking the precursor thin film to produce the antenna section 120, and a covering step of covering with a covering material. The precursor thin film may be formed by various methods such as a dry method using a vacuum device or the like, or a wet method using ink or the like.

[0054] In the film forming step, the portion on which the precursor thin film is formed becomes the conductive region 120a, and the portion on which the precursor thin film is not formed becomes the non-conductive region 120b.

[0055] Furthermore, if necessary, a through hole (not shown) may be formed penetrating from the covering material 150 to the base material 110 so as to penetrate at least a portion of the non-conductive region 120b. EXAMPLES

[0056] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0057] 1. Creating RF tags 20 parts by mass of cuprous oxide nanoparticles with a primary particle size of 21 nm, 4 parts by mass of a dispersant (manufactured by Big Chemie, product name: Disperbyk-145), 1 part by mass of a surfactant (manufactured by Seimi Chemical, product name: S-611), and 75 parts by mass of ethanol were mixed to prepare an ink containing 20% ​​by mass of cuprous oxide nanoparticles.

[0058] First, ink was applied to the surface of the transfer medium, and then the ink-coated surface of the transfer medium was brought into contact with a plate having grooves of a thin metal line pattern, and a portion of the ink on the surface of the transfer medium was transferred to the convex surface of the plate. After that, the surface of the transfer medium coated with the remaining ink was brought into contact with a transparent substrate, and the ink in the form of a thin metal line pattern was transferred onto the substrate. Through this process, a precursor thin film was produced. The thickness of this precursor thin film was 680 nm, the line width was 3 μm, and the pitch was 60 μm. Polyethylene terephthalate (PET) was used as the transparent substrate.

[0059] Next, a plasma was generated by microwaves generated at an output of 1.5 kW in an atmosphere containing 3% hydrogen by volume and 97% helium by volume under reduced pressure, and the plasma was reacted with the precursor thin film for 300 seconds to form an antenna part and a current collecting part. The pattern in the antenna part was a square grid with a line width W4 of 3.0 μm, an opening width W of 57 μm, a pitch of 60 μm, and a visible light transmittance T1 of 84%. Each antenna part (conductive region) was a rectangle with a short side of 10 mm and a long side of 50 mm.

[0060] When forming the precursor thin film, as shown in Table 1 below, a circular region where no film was formed and having a diameter of 3 mm, 5 mm, or 8 mm was provided at a distance L from the current collecting part, so that the antenna part also had a corresponding non-conductive region.

[0061] Then, a semiconductor element was bonded to the current collector using an anisotropic conductive paste, and a polyethylene terephthalate sheet was attached via a commercially available acrylic resin adhesive to cover the entire tag, forming a coating layer, thereby obtaining an RF tag as shown in Figure 1A. Note that the configuration of the non-conductive area of ​​the obtained RF tag follows Table 1, not Figure 1A.

[0062] [Table 1] *W is the diameter of the circle and is equivalent to W'.

[0063] 2. Communication Test Using the RF tags of each example obtained as described above, a test was conducted to measure the readable distance using the UHF band (920 MHz, wavelength 326 mm) to evaluate communication stability. For the measurement, Voyantic's Tagformance Pro was used to measure the theoretical read range forward. Figure 4 shows the relationship between the non-conductive area and the communication stability in the examples and comparative examples. The vertical axis of Figure 4 shows a relative evaluation of each example, with the measured value before the formation of the non-conductive area set to 1. [Industrial Applicability]

[0064] The RF tag of this embodiment has industrial applicability as an RF tag that can be used as a tag for apparel and the like. [Explanation of symbols]

[0065] 100... RF tag, 110... substrate, 120... antenna portion, 120a... conductive region, 120b, 120b1, 120b2, 120b3, 120b4... non-conductive region, 121... antenna pattern, 122... opening, 130... semiconductor element, 140... current collecting portion, 150... covering material

Claims

1. A substrate; an antenna portion having a substantially rectangular conductive region disposed on the base material; a semiconductor element disposed on the base material and electrically connected to the antenna portion; a current collecting portion that electrically connects the antenna portion and the semiconductor element; a covering material that covers the antenna portion, the semiconductor element, and the current collecting portion; The antenna portion has one or more non-conductive regions, In the width direction of the antenna portion, a total width W occupied by the non-conductive regions is less than 90%; The shortest distance L between the current collecting portion and the non-conducting region is 0.30% or more of the wavelength λ output by the antenna portion. RF tag.

2. In the non-conducting region closest to the current collecting portion, the ratio (W' / L) of the maximum width W' to the shortest distance L is 70 or less; The RF tag according to claim 1.

3. The conductive region contains at least one metal selected from the group consisting of copper, aluminum, silver, gold, and zinc. The RF tag according to claim 1.

4. The conductive region is formed of a substantially rectangular metal film or a thin metal wire extending in a substantially rectangular shape. The RF tag according to claim 1.

5. The line width of the metal thin wire is 0.25 μm or more and 200 μm or less. The RF tag according to claim 4.

6. The pitch interval of the metal thin wires is 1.0 μm or more and 300 μm or less. The RF tag according to claim 4.

7. A through hole is provided that passes through the coating material to the substrate, The through hole is formed so as to penetrate at least a part of the non-conductive region. The RF tag according to claim 1.

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