UHF radio tag and associated production method

Abstract

The invention relates to a UHF radio tag (1) comprising a transponder unit (11) and a support (12) made of a flexible and dielectric material to which the transponder unit is attached, the latter comprising an integrated circuit (111) and a conductive structure (112) electrically connected to the integrated circuit, wherein: - the support has two main faces (121, 122) opposite one another, and - the conductive structure comprises a via (1120) and two conductive tracks (1121, 1122), of which a first one extends over one of the two main faces of the support and a second one extends over the other one of the two main faces of the support at least partially in line with the first one, the conductive tracks being electrically connected to one another by the at least one via through the support, each via (1120) being crimped onto the support.

Description

[0001] “UHF radio tag and associated manufacturing process”

[0002] TECHNICAL FIELD

[0003] The present invention relates generally to radio frequency identification (RFID) devices or UHF radio tags and methods of manufacturing RFID devices or UHF radio tags. The present invention finds particular application in the affixing of UHF radio tags to packaging or products where there is little space to do so.

[0004] STATE OF THE ART

[0005] It is indeed of definite interest to be able to have UHF radio tags of a sufficiently small size to: a. present low visibility, and / or b. present a better hold on a product or packaging of small dimensions, and / or c. allow easier and discreet integration, for example between the layers of a cardboard constituting packaging, and / or d. be easier to integrate inside a product by an in-mould labelling process, and / or e. be more discreet than previous solutions, in particular when integrated under decorative films covering containers such as bottles (fruit juices, sodas, etc.) and flasks (hygiene or cleaning products, etc.).

[0006] In particular, in the clothing industry, it would be desirable to be able to insert a UHF radio tag into the hem of a garment, especially a lightweight one, without it being felt by the wearer of the garment. However, it is understood that the general problem set out above extends to a good number of other manufactured products and / or packaging where an insufficiently small UHF radio tag may be a problem, including: a. cosmetic products and / or packaging (eyeliner, lipstick, etc.), b. pharmacy products and / or packaging (syringes, bottles, etc.), c. office products and / or packaging, such as office supplies and school supplies (pens, erasers, etc.), and d.electronic products and / or packaging for which manufacturers must maintain compact packaging and space to include legal recommendations and instructions for use (electronic accessories, such as Bluetooth® headphones, SIM cards, etc.).

[0007] It should be noted that an additional difficulty arises, in the clothing industry, from the fact that clothes are intended to be cleaned, and in particular in a washing machine; thus, the proposed UHF radio tag should, preferably, retain its radiofrequency performance after two standard washes (i.e. at 60°C for two hours).

[0008] One purpose of using such UHF radio tags could be to enable "on-the-fly" inventory in stores (like any UHF radio tag), as well as to provide an anti-theft function.

[0009] To ensure these two radio frequency functions, the radio tag must operate in the ultra-high frequency (UHF) band. More specifically, a UHF radio tag must meet a number of specifications, for example those defined by the Auburn University standard and known under one of the names "Spec W", "Spec O", "Spec Y", or "Spec B1". For example, such a radio tag must preferably have a POTF (for "Power on Tag Forward") value strictly less than -16 dBm (decibel-milliwatts) in the ETSI (866 - 868 MHz) and FCC (902 - 928 MHz) bands.

[0010] The proposed UHF radio tag should therefore preferably offer a compromise between radio frequency performance and dimensions as small as possible, with, for the clothing industry, the additional constraint of resistance to washing.

[0011] Furthermore, since the quantities of UHF radio tags to be produced must be very large and the manufacturing cost must be as low as possible, it is desirable that the UHF radio tags can be obtained by a manufacturing process optimized in these respects. In this sense, it should be noted here that the manufacturing of UHF radio tag antennas benefits from relying on chemical etching of an aluminum layer, a mechanism that is well known and mastered in industry and is low cost, particularly relative to any conductive ink printing technique for forming the antenna. In this context, it is also understood that reducing the dimensions of UHF radio tags would optimize their costs in terms of the quantities of materials required for their manufacture.

[0012] Furthermore, it is known, from the patent document referenced WO 2004 / 086289 A2, an RFID device operating in the high frequency (HF) range, and not that of ultra-high frequencies (UHF), comprising a transponder unit and a support based on a flexible and dielectric material to which the transponder unit is fixed, the latter comprising an integrated circuit and a conductive structure electrically connected to the integrated circuit, in which: a. The support has two main faces opposite each other. b.The conductive structure comprises two conductive tracks, a first conductive track extending over one of the two main faces of the support and a second conductive track extending over the other of the two main faces of the support at least partly in line with the first conductive track, and the first conductive track and the second conductive track being electrically connected to each other by at least one via through the support. c. The two conductive tracks are configured to together form a closed loop made of an electrically conductive material allowing the device to communicate data and receive electrical energy for operation by induction.

[0013] According to the patent document referenced WO 2004 / 086289 A2, the perforations through which the vias extend are created by laser ablation configured to pierce the flexible support, and the perforations are then filled with silver-based conductive ink during a printing step optionally comprising the printing of one of the two conductive tracks.

[0014] The HF radio tag according to the patent document referenced WO 2004 / 086289 A2, as well as its manufacturing method, have at least the disadvantage that the conditions (temperature, viscosity, effusion, etc.) for operational filling of the perforations with conductive ink are difficult to meet, and make the proposed solution unsuitable for industrial exploitation.

[0015] Furthermore, because the conductive tracks according to the patent document referenced WO 2004 / 086289 A2 are configured to form an inductive loop, the radio tag described therein, in particular with reference to its figures 9A and 9B, is intended for use at high frequencies (HF) and is unsuitable for use at ultra-high frequencies (UHF).

[0016] SUMMARY

[0017] To achieve this objective, according to an embodiment of a first aspect of the invention, a UHF radio tag is provided, and in particular operating in the frequency range between 800 and 1000 MHz, comprising a transponder unit and a support based on a flexible and dielectric material to which the transponder unit is fixed, the latter comprising an integrated circuit and a conductive structure electrically connected to the integrated circuit, in which: a. The support has two main faces opposite each other, and b.The conductive structure comprises at least one via and at least two conductive tracks, a first conductive track extending over one of the two main faces of the support and a second conductive track extending over the other of the two main faces of the support at least partly in line with the first conductive track and the first conductive track and the second conductive track being electrically connected to each other by said at least one via through the support, c. The UHF radio tag being such that at least one via, preferably each via, is crimped onto the support.

[0018] As an alternative to the above statement, according to an embodiment of the first aspect of the invention, a radio tag is provided comprising a transponder unit and a support based on a flexible and dielectric material to which the transponder unit is fixed, the latter comprising an integrated circuit and a conductive structure electrically connected to the integrated circuit, in which: a. The support has two main faces opposite each other, and b. The conductive structure comprises at least one via at least two conductive tracks of which a first conductive track extends on one of the two main faces (of the support and a second conductive track extends on the other of the two main faces of the support at least partly in line with the first conductive track and the first conductive track and the second conductive track being electrically connected to each other by said at least one via through the support, c.The radio tag being such that at least one via, preferably each via, is crimped onto the support and that the radio tag, and more particularly its conductive structure, is configured to operate in the ultra-high frequency range, and in particular in the frequency range between 800 and 1000 MHz.

[0019] As an alternative to the above statements, according to an embodiment of the first aspect of the invention, a radio tag is provided comprising a transponder unit and a support based on a flexible and dielectric material to which the transponder unit is fixed, the latter comprising an integrated circuit and a conductive structure electrically connected to the integrated circuit, in which: a. The support has two main faces opposite each other, and b. The conductive structure comprises at least one via and at least two conductive tracks, a first conductive track extending on one of the two main faces (of the support and a second conductive track extending on the other of the two main faces of the support at least partly in line with the first conductive track and the first conductive track and the second conductive track being electrically connected to each other by said at least one via through the support, c.The radio tag being such that at least one via, preferably each via, is crimped onto the support and that the radio tag, and more particularly its conductive structure, is configured to satisfy at least one of the performance specifications defined by the Auburn University ARC program and known as “Spec W”, “Spec O”, “Spec Y”, or “Spec B1”.

[0020] A "via crimped onto the support" means that the via is the product of a crimping step applied to the support. Note here that it is deemed to fall within the ordinary skills of the person skilled in the art to determine whether or not a given via was obtained by a crimping step. In other words, there are clear differences between a via obtained by crimping and a via obtained by another technique, and the person skilled in the art knows how to distinguish them, whether the crimping was carried out with or without the addition of material.

[0021] According to a second aspect of the invention, a method is provided for manufacturing a UHF radio tag, and in particular operating in the frequency range between 800 and 1000 MHz, comprising a transponder unit and a support based on a flexible and dielectric material to which the transponder unit is fixed, the latter comprising an integrated circuit and a conductive structure electrically connected to the integrated circuit, the method comprising the steps of: a. Providing the support on which at least two conductive tracks extend, a first conductive track extending on one of two main faces of the support and a second conductive track extending on the other of the two main faces of the support at least partly in line with the first conductive track, then b. Transferring the integrated circuit onto the support so that the integrated circuit is electrically connected to the first conductive track, and c.Crimping at least one via configured to electrically connect the first conductive track and the second conductive track together through the support. d. Such that at least the first conductive track, the second conductive track and the at least one via together form a conductive structure and the integrated circuit and the conductive structure together form a transponder unit of the UHF radio tag.

[0022] As an alternative to the above statement, according to an embodiment of the second aspect of the invention, a method is provided for manufacturing a radio tag comprising a transponder unit and a support based on a flexible and dielectric material to which the transponder unit is fixed, the latter comprising an integrated circuit and a conductive structure electrically connected to the integrated circuit, the method comprising the steps of: a. Providing the support on which at least two conductive tracks extend, a first conductive track extending on one of two main faces of the support and a second conductive track extending on the other of the two main faces of the support at least partly in line with the first conductive track, then b. Transferring the integrated circuit onto the support so that the integrated circuit is electrically connected to the first conductive track, and c.Crimping at least one via configured to electrically connect the first conductive track and the second conductive track together through the support. d. Such that at least the first conductive track, the second conductive track and said at least one via together form a conductive structure, that the integrated circuit and the conductive structure together form a transponder unit of the radio tag and that the radio tag, and more particularly its conductive structure, is configured to operate in the ultra-high frequency range, and in particular in the frequency range between 800 and 1000 MHz.

[0023] As an alternative to the above statements, according to an embodiment of the second aspect of the invention, a method is provided for manufacturing a radio tag, in particular operating in the frequency range between 800 and 1000 MHz, comprising a transponder unit and a support based on a flexible and dielectric material to which the transponder unit is fixed, the latter comprising an integrated circuit and a conductive structure electrically connected to the integrated circuit, the method comprising the steps of: a. Providing the support on which at least two conductive tracks extend, a first conductive track extending on one of two main faces of the support and a second conductive track extending on the other of the two main faces of the support at least partly in line with the first conductive track, then b.Transferring the integrated circuit onto the carrier such that the integrated circuit is electrically connected to the first conductive track, and c. Crimping at least one via configured to electrically connect the first conductive track and the second conductive track together through the carrier. d. Such that at least the first conductive track, the second conductive track, and the at least one via together form a conductive structure, the integrated circuit and the conductive structure together form a transponder unit of the radio tag, and the radio tag, and more particularly its conductive structure, is configured to meet at least one of the performance specifications defined by the Auburn University ARC program and known as “Spec W,” “Spec O,” “Spec Y,” or “Spec B1.”

[0024] The invention according to these different aspects introduced above makes it possible to take advantage of the thickness of the support so that the conductive structure distributed on either side of the support creates a capacitive coupling allowing the radio tag to operate in the ultra-high frequency range. A UHF radio tag is thus proposed which, while allowing an “on-the-fly” inventory of the labeled products, can have a reduced size compared to the UHF radio tags known from the prior art. Therefore, relative to the latter, the radio tag proposed here can: a. have low visibility, and / or b. have a better hold on a product or packaging of small dimensions, and / or c. allow easier and more discreet integration, for example between the layers of a cardboard constituting a packaging, and / or d.be easier to integrate inside a product using an in-mold labeling process, and / or e. be more discreet than previous solutions, particularly when integrated under decorative films covering containers such as bottles (fruit juices, sodas, etc.) and flasks (hygiene or cleaning products, etc.).

[0025] According to an example of the second aspect of the invention, the step of providing the support comprises at least one chemical etching of an aluminum layer deposited on the support to form at least one, preferably each, of said at least two conductive tracks. According to another example of the second aspect of the invention, as an alternative or in addition to the previous example, the step of crimping at least one via comprises, preferably for each interconnection zone between the two conductive tracks, a step of crimping three vias aligned with each other along a straight line having an angular deviation a of between 0 and 10°, for example substantially equal to 2°, relative to a main extension direction of at least one of said two conductive tracks, each interconnection zone having for example: a. a width of between 0.3 and 1 mm, preferably substantially equal to 0.5 mm, and / or b.a length less than 10 mm, preferably substantially equal to 6 mm.

[0026] In particular, the invention according to these different aspects introduced above makes it possible, through its use in the clothing industry, to label clothing items by inserting a UHF radio tag as proposed in the hem of a garment, in particular a light one, without it being able to be felt by the wearer of the garment, while retaining its radiofrequency performance after two standard washes (i.e. at 60°C for two hours).

[0027] It is understood that the proposed UHF radio tag may be of a sufficiently small size for its use as labeling: a. of cosmetic products and / or packaging (eyeliner, lipstick, etc.), b. of pharmacy products and / or packaging (syringes, bottles, etc.), c. of office products and / or packaging, such as office supplies and school supplies (pens, erasers, etc.), and d. of electronic products and / or packaging for which manufacturers must keep packaging of small size and space to write legal recommendations and instructions for use (electronic accessories, such as Bluetooth® headphones, SIM cards, etc.).

[0028] Furthermore, since the size of the proposed UHF radio tags is reduced, they can be obtained by a manufacturing process optimized in terms of the quantity of material to be provided for their manufacture. Note that, in this respect in particular, the manufacture of the antennas of the proposed UHF radio tags can advantageously be based on chemical etching of an aluminum layer, a mechanism that is well known and mastered in industry and at low cost, in particular relative to any conductive ink printing technique for forming the antenna.

[0029] In this context, it is also understood that the present invention makes it possible to optimize the manufacturing costs of UHF radio tags.

[0030] BRIEF DESCRIPTION OF THE FIGURES

[0031] The aims, objects, as well as the characteristics and advantages of the invention will emerge more clearly from the detailed description of an embodiment thereof which is illustrated by the following accompanying drawings in which:

[0032] Figure 1 represents a schematic view in longitudinal section of a UHF radio tag according to a first embodiment of the invention.

[0033] Figure 2 represents a schematic longitudinal sectional view of a UHF radio tag according to a second embodiment of the invention. Figure 3 represents a schematic top view of an area of ​​the UHF radio tag according to the invention at the level of an electrical connection via between the conductive track visible in the figure and the conductive track located on the opposite face (not visible) of the support.

[0034] Figure 4A is a top view (with dimensions in mm) of an embodiment of a first conductive track of the UHF radio tag which is intended to be connected directly to the integrated circuit of the UHF radio tag.

[0035] Figure 4B is a top view (with dimensions in mm) of an embodiment of a second conductive track of the UHF radio tag which is intended to extend at least partly in line with the first conductive track illustrated in Figure 4A.

[0036] The drawings are given as examples and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily to the scale of practical applications. In particular, the relative thicknesses of the different elements illustrated are not necessarily representative of reality.

[0037] DETAILED DESCRIPTION

[0038] Before commencing a detailed review of embodiments of the invention, optional features of the first aspect of the invention which may optionally be used in combination or alternatively are set out below:

[0039] According to one example, at least one, preferably each, via is located at an area in which the first conductive track extends in line with the second conductive track.

[0040] According to one example, the first conductive track extends at all points in line with the second conductive track and / or the second conductive track does not extend at all points in line with the first conductive track.

[0041] According to one example, the conductive structure has a total length greater than 120 mm, preferably greater than 150 mm, and / or a width of between 0.1 and 1 mm, preferably substantially equal to 0.5 mm, and / or a thickness of between 5 and 20 pm, preferably substantially equal to 10 pm.

[0042] According to one example, the support has a length of between 70 and 150 mm and / or a width of between 0.5 and 1 mm, for example substantially equal to 1 mm, and / or a thickness of between 15 and 80 μm, preferably substantially equal to 38 μm or 50 μm.

[0043] According to one example, at least one via, preferably each via, has an average transverse dimension substantially less than or equal to 0.5 mm.

[0044] In one example, the conductive structure is made of aluminum.

[0045] In one example, the material from which the support is made is polyethylene terephthalate (PET) or paper.

[0046] According to one example, the support comprises, or even consists of, a thin film based on said flexible and dielectric material, preferably a film with a thickness of less than 100 μm, for example substantially equal to 50 μm.

[0047] According to one example, the conductive structure comprises two conductive tracks among which a first conductive track extending on the first main face of the support is that by which the conductive structure is electrically connected to the integrated circuit and a second conductive track extends on the second of the two main faces of the support at least partly in line with the first conductive track.

[0048] According to one example, the first conductive track has two ends, a first end of which is electrically connected to the second conductive track by at least one first via through the support and a second end is electrically connected to the second conductive track by at least one second via through the support.

[0049] According to the preceding example, at least one of the first conductive track and the second conductive track has, at each of its ends: a. a width of between 0.3 and 1 mm, preferably substantially equal to 0.5 mm, and / or b. a length of less than 10 mm, preferably substantially equal to 6 mm.

[0050] According to an example: a. the first conductive track has, along its length, a variable width, preferably regularly, or even periodically, between at least two values ​​different from each other, including a first value between 0.1 and 0.5 mm, preferably substantially equal to 0.2 mm, and a second value between 0.3 and 1 mm, preferably substantially equal to 0.5 mm, the wider parts of the first conductive track preferably taking a substantially square shape, and / or b. the second conductive track has a substantially constant width and substantially between 0.3 and 1 mm, preferably substantially equal to 0.5 mm.

[0051] According to the preceding example, the first conductive track comprising a plurality of zones of smaller width and a plurality of zones of larger width: a. A spacing between two zones of larger width is between 0.5 and 5 mm, preferably substantially equal to 1 mm, and / or b. The plurality of zones of larger width comprises between 10 and 100 zones, preferably between 20 and 50 zones, for example substantially 30 zones.

[0052] According to one example, the two ends of the first conductive track extend on either side and at a distance from the integrated circuit. Preferably, the first conductive track is symmetrical relative to a section plane passing through the integrated circuit.

[0053] According to one example, the second conductive track has a length strictly greater than the length of the first conductive track, preferably their centers being located at right angles to each other.

[0054] According to one example, the conductive structure further comprises two additional conductive tracks extending on the first main face of the support at a distance from the first conductive track and in which the second conductive track has two ends among which a first end is electrically connected to a first of the two additional conductive tracks by at least a third via through the support and a second end is electrically connected to a second of the two additional conductive tracks by at least a fourth via through the support. According to one example, each connection between two conductive tracks located on either side of the support comprises three vias aligned with each other along a straight line having an angular deviation a of between 0 and 10°, for example substantially equal to 2°, relative to a main extension direction of at least one of said two conductive tracks.

[0055] An element "at least partly in line with" another element relative to a support of these elements means that the orthogonal projections of said elements according to the thickness of the support overlap at least partially.

[0056] A film based on a material A means a film comprising this material A and possibly other materials.

[0057] A parameter that is "substantially equal to / greater than / less than" a given value means that this parameter is equal to / greater than / less than the given value, within plus or minus 20% or even 10% of this value. A parameter that is "substantially between" two given values ​​means that this parameter is at least equal to the smallest given value, within plus or minus 20% or even 10% of this value, and at most equal to the largest given value, within plus or minus 20% or even 10% of this value.

[0058] The term "ultra high frequency" (UHF) refers to frequencies in the radio spectrum band between 300 MHz and 3,000 MHz, i.e. wavelength frequencies between 1 m and 0.1 m.

[0059] A preferred embodiment of the invention is described below with reference to the accompanying figures.

[0060] Referring to Figure 1, the preferred embodiment of the first aspect of the invention constitutes a UHF radio tag 1.

[0061] Commonly, such a radio tag 1 comprises a transponder unit 11 and a support 12. Preferably, the support 12 is here based on a flexible and dielectric material, such as polyethylene terephthalate (PET) or paper. The transponder unit 11 is fixed to the support 12. The transponder unit 11 comprises an integrated circuit 111 (or electronic chip) and a conductive structure 112 electrically connected to the integrated circuit 111. The electrical connection of the integrated circuit 111 with the conductive structure 112 can be carried out according to the various techniques known for this purpose, and in particular by a wire wiring technique or, preferably, by a so-called flip chip technique. The support 12 has two main faces 121 and 122 opposite each other and separated, by construction, by a distance equal to the thickness of the support 12.The thickness of the support 12 can of course be constant, the distance separating them from the two main faces 121 and 122 of the support 12 can also be constant. The present invention is not, however, limited to a support 12 of constant thickness.

[0062] The conductive structure 112 comprises at least two conductive tracks 1121 and 1122, a first conductive track 1121 of which extends over a first main face 121 of the support 12 and a second conductive track 1122 of which extends over the second main face 122 of the support 12. The two conductive tracks 1121 and 1122 extend at least partly in line with each other; in other words, their orthogonal projections relative to the main faces 121 and 122 of the support 12 at least partially coincide with each other.

[0063] The conductive structure 112 also comprises at least one via 1120, preferably at least two vias 1120, configured to interconnect the first conductive track 1121 and the second conductive track 1122 through the thickness of the support 12.

[0064] The UHF radio tag 1 according to the preferred embodiment of the invention is essentially such that at least via 1120, preferably each via 1120, is crimped onto the support 12; in other words, each via 1120 is obtained by a crimping step. Such a crimping step may for example comprise all or part of an implementation of the crimping technique disclosed in the patent application referenced US 2018 / 0287324 A1. The technique disclosed in this document is a crimping technique without adding material, but other crimping techniques, in particular with adding material, are conceivable. The principle remains the same; this involves making a perforation through the support 12 and through at least one of the first conductive track 1121 and the second conductive track 1122, at the level of electrical connection zones of the conductive tracks between them, these zones being located in line with one another relative to the support 12.

[0065] Each via 1120 preferably extends through the support 12 in a main direction orthogonal, at least locally, to the main surfaces 121 and 122 of the support 12; it follows that each via 1120 is preferably located at the level of an area in which the first conductive track 1121 extends in line with the second conductive track 1122.

[0066] The conductive structure 112 can thus form a dipole antenna (also called a “dipole”), that is to say a radio antenna consisting of at least two metal strands and powered in its middle, intended to transmit or receive electromagnetic energy and / or radiofrequency signals carrying information, and in particular identification information. The dipole antenna that constitutes the conductive structure 112 must here allow at least one identification of each radio tag by an identification technology operating in the ultra high frequency (UHF) domain.

[0067] One of the objectives pursued by the present invention is to enable labeling of clothing products allowing their inventory on the fly, without constituting a hindrance for the wearer of the product (hence the necessary flexibility of the support 12). With this in mind, it is envisaged to insert the UHF radio tag 1 into a hem. A longitudinal shape, particularly narrow and not very thick, is more practical for this purpose; however, the support 12 delimits the extent of the conductive tracks 1 121 and 1122 which extend therein, and the dimensions of the conductive tracks, as well as the distance which separates them, must allow applications in the ultra high frequency range, which assumes that these dimensions respect certain minima. There is therefore a compromise to be found, a compromise to which the invention provides a response through the considerations below.

[0068] Preferably, the support 12 has a length of between 70 and 150 millimeters and / or a width substantially of between 0.5 and 1 mm, for example substantially equal to 1 mm. The length of each of the conductive tracks 1121 and 1122 cannot exceed the length of the support 12. Similarly, the width of each of the conductive tracks 1121 and 1122 cannot exceed the width of the support 12. On the other hand, the conductive tracks 1121 and 1122, extending on either side of the support 12, can advantageously have a cumulative / total length greater than the length of the support 12. To do this, it is sufficient for each of the conductive tracks 1121 and 1122 to extend strictly over more than half the length of the support 12. Preferably, each conductive track 1121 and 1122 extends over at least 70%, preferably 80%, and even more preferably 90%, of the length of the support 12.

[0069] The conductive structure 112 may thus have a total length greater than the length of the support 12, and more particularly greater than 120 mm, preferably greater than 150 mm. The width of the conductive tracks 1121 and 1122 is necessarily less than the width of the support 12; it is conceivable that the width of each conductive track is between 0.1 and 1 mm, but it will preferably be substantially equal to 0.5 mm, so as to be able to generate a capacitive coupling on which the physics implemented by the UHF type radio tags is based. Note here that the width of at least one of the two conductive tracks 1121 and 1122 is not necessarily constant; we will return to this point below with reference to FIG. 4A.

[0070] In order to ensure the generation of said capacitive coupling, other parameters are also important, including in particular the distance which separates the two conductive tracks 1121 and 1122, in other words the thickness of the support 12, and of course the thickness of the conductive tracks 1121 and 1122.

[0071] More particularly, the support 12 preferably has a thickness of between 15 and 80 microns, preferably between 40 and 70 microns, typically a thickness substantially equal to 38 or 50 microns. The conductive tracks 1121 and 1122 are therefore maintained between them at a distance of between 40 and 70 microns, preferably substantially equal to 50 microns, conducive to observing the aforementioned capacitive coupling.

[0072] The thickness of the conductive tracks 1121 and 1122 is typically between 5 and 20 microns, preferably substantially equal to 10 microns, which corresponds to the typical thickness of conductive tracks manufactured from etched aluminum, a well-known and industrially mastered technique for forming conductive tracks.

[0073] It should be noted that the conductive tracks 1121 and 1122 may have the same average width and the same thickness, without this being necessary. Preferably, the conductive tracks 1121 and 1122 do not have the same length, in particular so as to contribute to satisfactory capacitive coupling between them. Preferably, as illustrated in FIG. 1, the second conductive track 1122 is longer than the first conductive track 1121. Typically, the second conductive track 1122 may have a length at least 10%, preferably at least 20%, greater than the length of the first conductive track 1121.

[0074] Still with reference to FIG. 1, it is envisaged that the conductive tracks 1121 and 1122 are centered relative to each other in their length, in such a way that the orthogonal projection of the second conductive track 1122 extends, in its length, on either side of the orthogonal projection of the first conductive track 1121, by portions of lengths equal to each other.

[0075] Each via 1120, obtained by crimping, preferably does not have an average transverse dimension greater than the width of the support 12, but, on the contrary, has an average transverse dimension less than or equal to the width of the conductive tracks 121 and 122, or preferably substantially less than or equal to 0.5 mm. This advantageously prevents the crimped vias 1120 from stiffening the UHF radio tag 1 according to the first aspect of the invention.

[0076] As illustrated in Figure 1, the first conductive track 1121 has two ends by which it is, according to the preferred embodiment of the invention, connected to the second conductive track 1122. In other words, the first conductive track 1121 is preferably connected to the second conductive track 1122 by two vias 1120 crimped at the ends of the first conductive track 1121. The ends of the first conductive track 1121 therefore constitute a preferred interconnection zone of the first conductive track 1121 with the second conductive track 1122. It is understood here that it is at the level of the interconnection zones between conductive tracks, and not necessarily at other levels, that each of the conductive tracks 1121 and 1122 preferably has a width substantially greater than or equal to the average transverse dimension of the vias 1120.Typically, the first conductive track 1121 and the second conductive track 1122 may have, at each zone by which it is interconnected to the other track, a. a width of between 0.3 and 1 mm, preferably substantially equal to 0.5 mm, and / or b. a length of less than 10 mm, preferably substantially equal to 6 mm. We will return to this point below with reference to FIGS. 4A and 4B, but note here that the length of each interconnection zone between two conductive tracks is preferably greater than the width of this zone.

[0077] In this way, and with reference to FIG. 3, it is possible to produce not one via 1120 per interconnection zone, but a plurality of vias 1120 distributed over this zone, so as to ensure that the crimping step leads to electrical contact between the two tracks, if necessary by multiplying these interconnections. As illustrated in FIG. 3, three crimped vias 1120 may be provided per interconnection zone between the two conductive tracks, which may advantageously be aligned along a straight line forming an angle α which may be zero, but preferably less than 10°, for example substantially equal to 2°, relative to a main extension direction of the conductive tracks at the level of the zone.The method of manufacturing the UHF radio tag 1 according to the second aspect of the invention is thus made robust to inaccuracies in the alignment of the support 12 and / or the conductive tracks in the crimping device implemented.

[0078] Furthermore, still as illustrated in FIG. 1, the integrated circuit 111 is preferably connected to the first conductive track 1121 at the center of the latter, so that the first conductive track 1121 extends on either side of the integrated circuit 111 by portions of equal lengths. These portions may also be identical or different from each other.

[0079] With reference to FIG. 2, the conductive structure 112 may further comprise two additional conductive tracks 1123 and 1124 extending on the first main face 121 of the support 12 at a distance from the first conductive track 1121. And, the second conductive track

[0080] 1122 extending on the second main face 122 of the support 12 by portions in line with which the first conductive track 1121 does not extend, these portions may each comprise an interconnection zone with one of the two additional conductive tracks 1123 and 1124 by a crimped via 1120. In order to take full advantage of the length of the second conductive track 1122, these interconnection zones with the two additional conductive tracks

[0081] 1123 and 1124 are preferably located at its ends. Similarly, one and / or the other of the two additional conductive tracks 1123 and 1124 are preferably connected to the second conductive track 1122 by one of their ends, and more particularly by their ends closest to those of the support 12. The conductive structure 112 then comprises at least four vias 1120. In this way, each of the two additional conductive tracks 1123 and 1124 can extend at least partly in line with the second conductive track 1122, and thus participate in increasing the aforementioned capacitive coupling. It will be noted that the cumulative / total length of the conductive structure 112 is further advantageously increased, while the length of the support 12 can be the same as in the first embodiment illustrated in FIG. 1.Alternatively, it can be considered that, thanks to the two additional conductive tracks 1123 and 1124, the same cumulative length of the conductive tracks 1121, 1122, 1123 and 1124 can be achieved on a support 12 of shorter length. The two additional conductive tracks 1123 and 1124 thus operate a folding of the dipole antenna which it is understood can make it possible to increase the capacitive coupling of the UHF radio tag 1, in particular at a constant length of support 12, and / or to reduce the dimensions of the support 12, and in particular its length, at constant capacitive coupling.

[0082] Note that it is of course possible to provide other additional conductive tracks, in particular electrically connected to the two additional conductive tracks 1123 and 1124 mentioned above by vias specific to these interconnections, and if necessary at the level of interconnection zones which are not located at the right of the second conductive track 1122.

[0083] The above description is based on sectional views of the UHF radio tag 1 according to the first aspect of the invention. Figures 4A and 4B advantageously supplement the first illustrations which constitute in particular Figures 1 and 2, by representing only the first conductive track 1121 and the second conductive track 1122, respectively, but in top view. These illustrations have the additional advantage of making it possible to show the dimensions in millimeters of each part of each of the conductive tracks 1121 and 1122 illustrated.

[0084] As illustrated in FIG. 4A, the first conductive track 1121 may have, along its length, a variable width. Preferably, and still as illustrated in FIG. 4A, the variation in width of the first conductive track 1121 is regular, or even periodic, over at least part of its length, and more particularly over two parts of its length extending from interconnection pads with the integrated circuit 111. It can be seen in fact, in FIG. 4A, that the first conductive track 1121 is in fact made up of two parts intended to extend respectively on either side of the integrated circuit 111 and whose facing ends form pads, i.e. contact recovery zones of the conductive track with the integrated circuit 111.

[0085] Still with reference to FIG. 4A, the width of the first conductive track 1121 may more particularly vary between at least two values ​​different from each other, including a first value between 0.1 and 0.5 mm, preferably substantially equal to 0.2 mm, and a second value between 0.3 and 1 mm, preferably substantially equal to 0.5 mm. In addition, the wider parts of the first conductive track 1121 preferably take a substantially square shape, it being understood that any other shape is possible.

[0086] Unlike the first conductive track 1121, and with reference to FIG. 4B, the second conductive track 1122 preferably has a constant width, typically substantially between 0.3 and 1 mm, preferably substantially equal to 0.5 mm. It follows that the main generatrices of the first and second conductive tracks 1121 and 1122 can be strictly located in line with each other, without each point of one of the two conductive tracks being located in line with a point of the other of the two conductive tracks. More particularly, in the example illustrated in FIGS. 4A and 4B, the first conductive track 1121 can extend at all points in line with the second conductive track 1122, but the second conductive track 1122 does not extend at all points in line with the first conductive track 1121.

[0087] It will be noted, in view of FIG. 4A, that the ends 1121a to 1121b of the first conductive track 1121 which constitute, as already mentioned above, interconnection zones with the second conductive track 1122 have the greater of the two width values ​​of the first conductive track 1121. The dimensions indicated for illustrative purposes in FIG. 4A of these interconnection zones fall within the ranges of values ​​previously indicated for these zones, in particular with regard to the average transverse dimension of each via 1120. It will also be noted, in view of FIG. 4B, that the interconnection zones 1122a and 1122b of the second conductive track 1122 with the first conductive track 1121 preferably have the same width as that of the first conductive track 1121 at its ends 1121a and 1121b.

[0088] With reference to Figure 4A, the first conductive track 1121 comprising a plurality of zones of smaller width and a plurality of zones of larger width: a. A spacing between two zones of larger width may be between 0.5 and 5 mm, and may preferably be substantially equal to 1 mm, and / or b. The plurality of zones of larger width may comprise between 10 and 100 zones, preferably between 20 and 50 zones, and comprise for example substantially 30 zones, where appropriate intended to be distributed on either side of the integrated circuit 111.If the dimensions of each of the two conductive tracks 1121 and 1122 may be different from those indicated in FIGS. 4A and 4B, it will be noted that it is particularly advantageous, in particular to ensure satisfactory capacitive coupling between these two conductive tracks, that one of the two has a geometry in the main extension plane of the support 12 different from the geometry of the other of the two conductive tracks.

[0089] If the first aspect of the invention relates to a UHF radio tag 1 as described above, the invention also relates, according to a second aspect, to a method of manufacturing such a UHF radio tag.

[0090] More particularly, the manufacturing method according to the second aspect of the invention may comprise the following steps consisting of: a. Providing the support 12 on which at least two conductive tracks 1121, 1122, 1123, 1124 extend, a first conductive track 1121 of which extends on one 121 of two main faces 121, 122 of the support 12 and a second conductive track 1122 extends on the other 122 of the two main faces 121, 122 of the support 12 at least partly in line with the first conductive track 1121, then b. Transferring the integrated circuit 111 onto the support 12 so that the integrated circuit 111 is electrically connected to the first conductive track 1121, and c. Crimp at least one via 1120 configured to electrically connect the first conductive track 1121 and the second conductive track 1122 to each other through the support 12.

[0091] In this way, at least the first conductive track 1121, the second conductive track 1122 and said at least one via 1120 together form a conductive structure 112 and the integrated circuit 111 and the conductive structure 112 together form a transponder unit 11 of the UHF radio tag 1.

[0092] It will be noted that steps b and c can be implemented in one order or the other. It is therefore understood that the manufacturing method according to the second aspect of the invention lends itself to the manufacturing of an intermediate product, comprising the support 12, the conductive tracks and the vias 1120, which can be delivered, in B to B, to another player in the sector who will be responsible for functionalizing the dipole antenna constituted by the conductive structure 112, in particular by transferring the integrated circuit 111 onto the first conductive track 1121 of the conductive structure 112.

[0093] Furthermore, the step of providing the support 12 may advantageously comprise at least one chemical etching of an aluminum layer deposited on the support 12 to form at least one, preferably each, of said at least two conductive tracks 1121, 1122, 1123 and 1124. In other words, the manufacturing method according to the second aspect of the invention is compatible with a technique for forming conductive tracks which is known and well mastered industrially, which represents a definite advantage relative to any technique for forming conductive tracks by printing a conductive ink, for example.

[0094] Thanks to the manufacturing method according to the second aspect of the invention, it is now possible to produce UHF 1 radio tags according to the first aspect of the invention in very large quantities, with a very low manufacturing cost. It should be remembered here that such UHF 1 radio tags can provide, in addition to an on-the-fly inventory, an anti-theft function.

[0095] The present invention therefore makes it possible to design and manufacture a UHF radio tag 1, which is efficient and compact, by using the two main faces of the support 12, the latter therefore being comparable to an inlay, and by making use of electrical connection techniques by crimping.

[0096] The invention is not limited to the embodiments previously described and extends to all embodiments covered by the invention.

[0097] In this sense, let us note that, rather than a variation in the width of the first conductive track 1121 in its length, it is conceivable that this track is of a substantially constant width, but undulates on either side of the main direction of extension of the first conductive track 1121, in particular so that, here again, the second conductive track 1122 does not extend at all points in line with the first conductive track 1121.

[0098] Note also that the vias 1120 are not necessarily filled (with electrically conductive material); alternatively, each via can form a blind hole or a through hole in the support 12.

[0099] Furthermore, it should be noted that the UHF radio tag 1 according to the first aspect of the invention may be free of an electrical power supply device, such as a battery. In other words, the UHF radio tag 1 according to the first aspect of the invention may be passive.

[0100] It should be noted that the flexibility of the support is more required when it comes to labeling clothing without causing discomfort to the wearer, than when the UHF 1 radio tag is intended to be overmolded in a product or packaging or inserted into a rigid product or packaging.

[0101] Furthermore, if the preferred embodiment of the invention as described above takes an essentially longitudinal shape, it is conceivable that this shape has at least one bend.

[0102] If the different embodiments illustrated in the figures comprise a minimum of two vias 1120, the present invention extends to a UHF radio tag 1 comprising only a single via 1120 and to its manufacturing method.

Claims

Claims 1. UHF radio tag (1) comprising a transponder unit (11) and a support (12) based on a flexible and dielectric material to which the transponder unit (11) is fixed, the latter comprising an integrated circuit (111) and a conductive structure (112) electrically connected to the integrated circuit (111), in which: • The support (12) has two main faces (121, 122) opposite each other, and • The conductive structure (112) comprises at least one via (1120) and at least two conductive tracks (1121, 1122, 1123, 1124) of which a first conductive track (1121) extends on one (121) of the two main faces (121, 122) of the support (12) and a second conductive track (1122) extends on the other (122) of the two main faces (121, 122) of the support (12) at least partly in line with the first conductive track (1121) and the first conductive track and the second conductive track being electrically connected to each other by said at least one via (1120) through the support (12), • The UHF radio tag (1) being characterized in that at least one via (1120), preferably each via (1120), is crimped onto the support.

2. UHF radio tag (1) according to the preceding claim, in which the conductive structure (112) has a total length greater than 120 mm, preferably greater than 150 mm, and / or a width of between 0.1 and 1 mm, preferably substantially equal to 0.5 mm, and / or a thickness of between 5 and 20 pm, preferably substantially equal to 10 pm.

3. UHF radio tag (1) according to any one of the preceding claims, in which the support (12) has a length of between 70 and 150 mm and / or a width of between 0.5 and 1 mm, for example substantially equal to 1 mm, and / or a thickness of between 15 and 80 pm, preferably substantially equal to 38 or 50 pm.

4. UHF radio tag (1) according to any one of the preceding claims, in which at least one via (1120), preferably each via (1120), has an average transverse dimension substantially less than or equal to 0.5 mm.

5. UHF radio tag (1) according to any one of the preceding claims, in which the conductive structure (112) is based on aluminum.

6. UHF radio tag (1) according to any one of the preceding claims, in which the conductive structure (112) comprises two conductive tracks (1121, 1122) among which a first conductive track (1121) extending on the first main face (121) of the support (12) is that by which the conductive structure (112) is electrically connected to the integrated circuit (111) and a second conductive track (1122) extends on the second (122) of the two main faces (121, 122) of the support (12) at least partly in line with the first conductive track (1121).

7. UHF radio tag (1) according to the preceding claim, in which the first conductive track (1121) has two ends (1121 a, 1121 b) among which one first end (1121 a) is electrically connected to the second conductive track (1122) by at least one first via (1120) through the support (12) and a second end (1121 b) is electrically connected to the second conductive track (1122) by at least one second via (1120) through the support (12).

8. UHF radio tag (1) according to the preceding claim, in which at least one of the first conductive track (1121) and the second conductive track (1122) has, at each of its ends (1121 a, 1121 b, 1122a, 1122b): • a width of between 0.3 and 1 mm, preferably substantially equal to 0.5 mm, and / or • a length less than 10 mm, preferably substantially equal to 6 mm.

9. UHF radio tag (1) according to any one of the three preceding claims, in which: • the first conductive track (1121) has, along its length, a variable width, preferably regularly, or even periodically, between at least two values different from each other, including a first value between 0.1 and 0.5 mm, preferably substantially equal to 0.2 mm, and a second value between 0.3 and 1 mm, preferably substantially equal to 0.5 mm, the wider parts of the first conductive track (1121) preferably taking a substantially square shape, and / or • the second conductive track (1122) has a substantially constant width and substantially between 0.3 and 1 mm, preferably substantially equal to 0.5 mm.

10. UHF radio tag (1) according to the preceding claim, in which, the first conductive track (1121) comprising a plurality of zones of smaller width and a plurality of zones of larger width: • A spacing between two zones of greater width is between 0.5 and 5 mm, preferably substantially equal to 1 mm, and / or • The plurality of zones of greater width comprises between 10 and 100 zones, preferably between 20 and 50 zones, for example substantially 30 zones.

11. UHF radio tag (1) according to any one of the five preceding claims, in which the second conductive track (1122) has a length strictly greater than the length of the first conductive track (1121), preferably their centers being located in line with each other.

12. UHF radio tag (1) according to any one of the six preceding claims, wherein the conductive structure (112) further comprises two additional conductive tracks (1123, 1124) extending on the first main face (121) of the support (12) at a distance from the first conductive track (1121) and in which the second conductive track (1122) has two ends (1122a, 1122b) among which a first end (1122a) is electrically connected to a first (1123) of the two additional conductive tracks by at least a third via (1120) through the support (12) and a second end (1122b) is electrically connected to a second (1124) of the two additional conductive tracks by at least a fourth via (1120) through the support (12).

13. UHF radio tag (1) according to any one of the preceding claims, in which each connection between two conductive tracks (1121, 1122, 1123, 1124) located on either side of the support (12) comprises three vias (1120) aligned with each other along a straight line having an angular deviation a of between 0 and 10°, for example substantially equal to 2°, relative to a main direction of extension of at least one of said two conductive tracks.

14. Method for manufacturing a UHF radio tag (1) comprising a transponder unit (11) and a support (12) based on a flexible and dielectric material to which the transponder unit (11) is fixed, the latter comprising an integrated circuit (111) and a conductive structure (112) electrically connected to the integrated circuit (111), the method comprising the steps of: • provide the support (12) on which at least two conductive tracks (1121, 1122, 1123, 1124) extend, of which a first conductive track (1121) extends on one (121) of two main faces (121, 122) of the support (12) and a second conductive track (1122) extends on the other (122) of the two main faces (121, 122) of the support (12) at least partly in line with the first conductive track (1121), then • transferring the integrated circuit (111) onto the support (12) so that the integrated circuit (11) is electrically connected to the first conductive track (1121), and • crimp at least one via (1120) configured to electrically connect the first conductive track (1121) and the second conductive track (1122) together through the support (12), • such that at least the first conductive track (1121), the second conductive track (1122) and said at least one via (1120) together form a conductive structure (112) and that the integrated circuit (111) and the conductive structure (112) together form a transponder unit (11) of the UHF radio tag (1).

15. Manufacturing method according to the preceding claim, wherein the step of providing the support (12) comprises at least one chemical etching of an aluminum layer deposited on the support (12) to form at least one, preferably each, of said at least two conductive tracks (1121, 1122, 1123, 1124). According to one example, the step of crimping at least one via (1120) comprises, preferably for each interconnection zone between the two conductive tracks, a step of crimping three vias (1120) aligned with each other along a straight line having an angular deviation a of between 0 and 10°, for example substantially equal to 2°, relative to a main extension direction of at least one of said two conductive tracks, each interconnection zone having for example: - a width of between 0.3 and 1 mm, preferably substantially equal to 0.5 mm, and / or - a length less than 10 mm, preferably substantially equal to 6 mm.

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