Method for manufacturing RFID tags

Abstract

The invention relates to the method for manufacturing at least two narrow strips (41, 42) of RFID tags, the method comprising: • forming a plurality of inlays (23) on a first film (11), these inlays being arranged parallel to a first leading edge (11a) of the first film; • cutting the first film (11) into a plurality of formats (F) comprising N inlays (23); • rotating each format (F) by 90° about a direction normal to the format (F); • forming a wide strip (30) of inlays (23) by depositing the rotated formats (F) on a second film (12); • cutting the wide strip (30) parallel to the columns (31) so as to form at least two narrow strips (41, 42) of RFID tags (20), each having a third leading edge (41a, 42a), wherein each RFID tag (20) comprises an inlay (23) perpendicular to the third leading edge (41a, 42a).

Description

[0001] "RFID label manufacturing process"

[0002] TECHNICAL FIELD

[0003] The present invention relates to the production of RFID (Radio Frequency Identification) tags. Its particularly advantageous application lies, for example, in the management of the distribution chain for industrial products.

[0004] STATE OF THE ART

[0005] RFID tags, comprising an antenna and a chip, are widely used in various applications, from inventory management to product traceability. These RFID tags are produced using strategic manufacturing processes, ultimately resulting in RFID tag strips delivered in reels or rolls with different configurations.

[0006] A commonly used configuration is the "WEL" (Wide-Edge Leading) configuration, where the antennas are arranged on a strip so that one length of the antenna is perpendicular to the direction of the strip's feed and parallel to the leading edge. The chips are typically placed onto these antennas using pick-and-place machines, offering efficient production. For high-volume RFID tag production, it is preferable to arrange the antennas in a WEL configuration with a small pitch between successive antennas. Consequently, conventional pick-and-place machines are optimized for small pitches and large strip widths, thus facilitating strip pulling through the machine.

[0007] Another RFID tag configuration exists, known as the "NEL" (Narrow-Edge Leading) configuration. In this configuration, the antennas are arranged parallel to the direction of tape feed and perpendicular to the leading edge. This configuration allows for narrow tape rolls, which are advantageous for certain applications, such as traceability of fine products. The pick-and-place method in this case can present challenges, notably the need to traverse the length of one antenna to move to the next, thus lengthening the manufacturing process. Furthermore, adjustments may be necessary to adapt the machines to the narrow tape widths, or to trim excess tape material at the end of the process to obtain narrower tapes, which can be costly.

[0008] The present invention proposes to overcome, at least in part, the drawbacks of known methods. In particular, one objective of the present invention is to optimize the manufacturing process for narrow RFID label reels.

[0009] SUMMARY

[0010] To achieve this objective, according to a first aspect of the invention, a method for manufacturing at least two narrow strips of RFID tags is provided, comprising the following steps:

[0011] • A supply of a first film having a plurality of parallel antennas, arranged such that a first principal extension direction of the antennas is parallel to a first leading edge of the first film,

[0012] • The formation of a plurality of antenna-chip assemblies, known as "inlays," on the first film, by depositing a chip on each of the antennas,

[0013] • A division of the first film along the first direction, into a plurality of formats, each format comprising N inlays, N being a positive integer greater than or equal to 2,

[0014] • A 90° rotation of each format around a direction normal to the format,

[0015] • The formation of a wide strip of inlays, by depositing the filmed formats onto a second film, such that a second principal extension direction of the N inlays is perpendicular to a second leading edge of the wide strip, and that the inlays of successive formats form N columns extending along the wide strip,

[0016] • A cutting of the wide strip parallel to the columns so as to form M narrow strips of RFID tags each having a third leading edge, M being a positive integer greater than or equal to 2 and less than or equal to N and each RFID tag comprising an inlay perpendicular to the third leading edge.

[0017] Format reorientation allows a series of inlays arranged in a WEL configuration to ultimately result in a series of labels arranged in a NEL configuration. This transition from a WEL to a NEL configuration during the RFID label manufacturing process makes it possible to use conventional methods and machines configured and optimized for WEL RFID label manufacturing to produce labels arranged in a NEL configuration. Pick-and-place methods, for example, used to deposit chips onto antennas, are optimized for the WEL configuration. This avoids scanning the length of the antennas, which is generally greater than their width, to deposit chips by moving from one antenna to the next, thus accelerating the manufacturing process.

[0018] Furthermore, this transition overcomes the limitations imposed by conventional chip deposition methods on the width of RFID tag film. Indeed, the leading edge of the antenna film feeding a pick-and-place machine must be quite wide, preferably more than 40 mm, to ensure traction of the antenna film within the machine, making it difficult to manufacture a narrow RFID tag strip. The process described above resolves this limitation by deploying a WEL configuration during chip deposition onto the antennas and then reorienting the inlays to obtain RFID tags in a NEL configuration, thus significantly reducing the leading edge width of the final strip.

[0019] Furthermore, this process allows for the production of a batch of several series or strips of NEL-type labels, which is advantageous not only for large-scale production but also for the widespread application of the labels to industrial products. A second aspect of the invention relates to a narrow strip of RFID labels having a third leading edge, each RFID label comprising an inlay perpendicular to the third leading edge, each inlay comprising an antenna and a chip, the narrow strip being wound into a narrow reel.

[0020] The RFID label roll is often integrated into an automatic labeling machine positioned within an industrial production line. It is typically loaded onto the machine, which then automatically dispenses the labels. The arrangement of the inlays perpendicular to the leading edge of the strip (or parallel to the direction of unwinding), along with the strip's narrow width, facilitates automatic pick-up and unwinding.

[0021] BRIEF DESCRIPTION OF THE FIGURES

[0022] The aims, objects, features and advantages of the invention will become clearer from the detailed description of an embodiment thereof, which is illustrated by the following accompanying drawings in which:

[0023] Figure 1 schematically illustrates, according to an example of implementation, a narrow strip of RFID tags wound on a reel.

[0024] Figures 2 to 5 schematically illustrate a top view in an XY plane of the manufacturing steps of at least one narrow strip of RFID tags.

[0025] Figure 6 schematically illustrates a top view in an XY plane of a manufacturing step for at least one narrow strip of RFID tags according to a first embodiment. Figure 7 schematically illustrates a top view in an XY plane of a manufacturing step for at least one narrow strip of RFID tags according to a second embodiment.

[0026] Figure 8 schematically illustrates, as an example, a longitudinal section in the XZ plane of an RFID tag. Figure 9 schematically illustrates, as an example, a top view in the XY plane of a manufacturing step for at least one narrow strip of RFID tags.

[0027] Figures 10 to 12 schematically illustrate an example of the manufacturing steps for at least one narrow strip of RFID tags.

[0028] Figure 13 schematically illustrates, according to an example of implementation, a narrow strip of RFID tags wound in a cross-roll.

[0029] The drawings are provided as examples and are not intended to limit the scope of the invention. They are schematic representations of the principle intended to facilitate understanding of the invention and are not necessarily to scale with practical applications. In particular, the thicknesses and / or dimensions of the various layers, patterns, and reliefs are not necessarily representative of reality.

[0030] DETAILED DESCRIPTION

[0031] Before proceeding with a detailed review of embodiments of the invention, the following are optional features that may be used in combination or alternatively:

[0032] According to one example, the narrow band has a width W nThe size ranges from 0.6 mm to 750 mm. For example, the format placement on the second film is configured so that the formats are aligned with each other using patterns present on the second film. The presence of these registration patterns on the second film allows for precise positioning of the formats relative to one another. This precise positioning ensures a consistent spacing between the RFID tags. Furthermore, it allows the antennas of two successive formats to be aligned side-by-side, forming regular antenna columns. This then enables the wide band to be cut straight parallel to the antenna columns, resulting in straight narrow bands without damaging the antennas.

[0033] In one example, the patterns could be registration marks. In another example, the patterns could be holes or centering pins.

[0034] According to one example, the supply of a first film comprising a plurality of parallel antennas is configured such that two successive antennas are separated by a distance d a greater than or equal to 2.5 mm. In the context of chip deposition on antennas using a Pick-and-Place method, for example, the distance d a The distance between two successive antennas must be minimized to optimize manufacturing time. This distance can be reduced to as little as 2.5 mm during the delivery of antennas arranged in a WEL configuration, significantly reducing the time required for this pick-and-place step.

[0035] According to one example, the second film on which the formats are placed after their rotation includes a first underlayer based on an adhesive material which allows the formats to be fixed.

[0036] In one example, the first sublayer of the second adhesive film is placed on top of a second sublayer, known as the carrier layer. In another example, the second film may include a third sublayer made of an adhesive material, which lies beneath the second sublayer.

[0037] According to one example, the adhesive material is based on Thermoplastic Polyurethane (“TPU” or “Thermoplastic Polyurethane” in English).

[0038] As an example, the third sub-layer of the second film can be protected by a fourth underlying sub-layer based on silicone, for example.

[0039] As an example, the adhesive material can be permanent or non-permanent.

[0040] According to one example, the manufacturing process for at least two narrow strips of RFID tags further includes the deposition of at least one protective layer on at least the chip of each inlay.

[0041] In one example, the protective layer covers the chip and part of the antenna of an inlay. In another example, the protective layer covers the entire inlay.

[0042] As an example, several layers of protection can be superimposed on at least the chip of each inlay.

[0043] This protective layer helps to protect the antennas and / or chips against mechanical damage, scratches, shocks and other external aggressions that could impair their operation.

[0044] In one example, the protective layer is based on an adhesive material.

[0045] In one example, the cutting of the first film and / or the wide strip is done using a laser beam.

[0046] In one example, the cutting of the first film and / or the wide strip is done using a sharp tool.

[0047] According to one example, the manufacturing process for at least two narrow strips of RFID labels further includes laminating the wide strip with inlays.

[0048] Laminating the wide strip of inlays improves the adhesion of the formats to the first film, or of the protective layer to the inlays, and improves the compactness of the wide strip of inlays.

[0049] According to one example, lamination is achieved by heating the wide strip of inlays.

[0050] According to one example, lamination is achieved by applying pressure to the wide strip of inlays.

[0051] According to one example, the lamination of the wide strip of inlays is carried out flat by scrolling the formats one after the other.

[0052] In one example, lamination is carried out continuously by conveying the wide strip of inlays between heated rollers.

[0053] In one example, the wide stripe is configured so that each narrow stripe of RFID tags comprises a single column of inlays. In this example, the resulting number M of narrow stripes equals the number N of inlay columns. The so-called "single-strand" narrow stripe comprises a single series of RFID tags, which significantly reduces the leading edge width. In another example, the format deposition on the second film is configured so that every two successive antennas in the same column of inlays overlap, thus creating continuity between the antennas in the same column.

[0054] According to one example, the format deposition on the second film is configured so that every two successive antennas of the same column of inlays are disjoint.

[0055] As an example, every two successive antennas in the same column of inlays overlap by a few millimeters. The continuity between the antennas in a column of inlays saves adhesive material and improves the compactness of the narrow coils obtained at the end of the process.

[0056] According to one example, the manufacturing process for at least two narrow strips of RFID tags further includes ultrasonic welding of the overlapping areas between the antennas of the same column.

[0057] In one example, the cutting of the wide RFID tag strip is configured so that each narrow strip of RFID tags contains at least two columns of inlays. In this example, the number M of narrow strips obtained is less than the number N of columns of inlays. The narrow strip, referred to as "multi-strand," contains at least two RFID tags across its width. Each narrow strip obtained at the end of the process undergoes a testing step, which can be costly. The larger the number of rolls, the higher the cost of this step. Manufacturing multi-strand strips reduces the costs of the testing step.

[0058] For example, the number N of inlays per format is between 2 and 150. For example, a narrow band can contain between 2 and N columns of inlays. For example, a narrow band can contain 7 or 8 columns of inlays.

[0059] As an example, the manufacturing process for at least two narrow strips of RFID tags further includes winding each narrow strip of RFID tags into a narrow reel. Winding the narrow strips of RFID tags into reels facilitates the handling and delivery of the RFID tags.

[0060] As an example, the winding of narrow strips of RFID tags into reels is done by overlapping.

[0061] As an example, narrow strips are wound into narrow reels using a cross-winding technique. In a narrow reel of RFID tags wound in an overlapping pattern, the RFID tag chips are subjected to mechanical stress. Cross-winding allows the chips to be distributed across the width of a core, for example, thus reducing the stress on the chips.

[0062] As an example, each RFID tag in the narrowband has a width W e between 0.6 mm and 5 mm.

[0063] These narrow RFID tags are designed for integration into finished products, whether in the clothing industry, pharmaceuticals (tubes, syringes), cosmetics (lipstick or eyeliner, for example), or any other industrial product requiring the integration of a thin RFID tag. For example, each RFID tag has a second length (Le) ranging from 50 mm to 250 mm.

[0064] As an example, each antenna in the narrowband RFID tag has a width W a between 0.3 mm and 3 mm. For example, the width W a the diameter of an antenna is equal to 1.5 mm.

[0065] It is specified that, within the framework of the present invention, the terms "on", "overcomes", "covers", "underlying", "opposite" and their equivalents do not necessarily mean "in contact with". Thus, for example, the deposit or application of a first layer on a second layer does not necessarily mean that the two layers are directly in contact with each other, but means that the first layer at least partially covers the second layer by being either directly in contact with it, or by being separated from it by at least one other layer or at least one other element.

[0066] The steps of the process are understood in the broad sense of carrying out a part of the process and may optionally be carried out in several sub-steps. Several embodiments of the invention implementing successive steps of the manufacturing process are described below. Unless explicitly stated, the adjective "successive" does not necessarily imply, although this is generally preferred, that the steps follow each other immediately; intermediate steps may separate them.

[0067] Furthermore, the term "step" does not necessarily imply that the actions carried out during a step are simultaneous or immediately successive. Some actions in a first step may be followed by actions related to a different step, and other actions from the first step may be repeated later. Thus, the term "step" does not necessarily refer to unitary actions that are inseparable in time and in the sequence of phases of the process.

[0068] A substrate, layer, or device "based" on a material M is understood to mean a substrate, layer, or device comprising only that material M or that material M and possibly other materials.

[0069] An orthonormal coordinate system, including the X, Y, Z axes, is shown in the attached figures.

[0070] Dimensional values ​​are understood to be within manufacturing and measurement tolerances.

[0071] The terms "approximately," "about," and "on the order of" mean, when referring to a value, "within 10%" of that value, or, when referring to an angular orientation, "within 10°" of that orientation. Thus, a direction approximately normal to a plane means a direction at an angle of 90±10° to the plane.

[0072] It is specified that, within the framework of the present invention, the thickness of a layer or substrate is measured along a direction perpendicular to the surface along which this layer or substrate has its maximum extent. The thickness is thus taken along a direction perpendicular to the principal faces of the layer or substrate on which the various layers rest. More particularly, the thickness can be taken along the Z direction. A narrow strip 41 wound onto a reel 71 is now described with reference to Figure 1, according to an exemplary embodiment.

[0073] Figure 1 illustrates a narrow strip 41 comprising at least one column 31 of RFID tags 20. Each RFID tag 20 includes an antenna 21 surmounted by a chip 22. The antennas 21, or the RFID tags 20, are arranged perpendicularly to a leading edge 41a of the narrow strip. In other words, the narrow reel 41 adopts a NEL configuration. The narrow strip 41 is wound into a narrow reel 71 around a core 134. This narrow reel 71 is intended to be delivered as a finished product. The RFID tags 20 can then be applied to industrial products and configured using an RFID reader to identify and track the tagged products.

[0074] The narrow 41-strip RFID 20-tag NEL configuration has a width W n reduced. This width W nThe reduced width facilitates the integration of the reels into automated processing or application systems. Furthermore, automated handling and reel unwinding are generally simpler for a NEL configuration than for a WEL configuration. RFID tags 20 also feature a W width. e Reduced size. Because narrow RFID tags use less material, the corresponding rolls can be less expensive to produce. Furthermore, narrow RFID tags can be advantageously applied to thin or small objects, or products with limited labeling space. Narrow RFID tags can also be more flexible and adapt more easily to curved or irregular surfaces.

[0075] The manufacturing process for such a narrow strip 41 of RFID tags is now described with reference to Figures 2 to 9. This process makes it possible to obtain in the end at least two narrow strips 41, 42, of RFID tags 20 arranged parallel to the leading edge of the strip.

[0076] As illustrated in Figure 2, the process comprises supplying a first film 11 having a first leading edge 11a along a Y direction and a first upper surface 11b surmounted by a plurality of antennas 21. Such a film 11 including antennas can be commercially available. It can be produced by an antenna supplier using a standard process, such as chemical etching of a metal like aluminum bonded to a PET (polyethylene terephthalate) film. The antennas 21 are arranged parallel to each other along the Y direction, in a WEL configuration. In other words, the antennas 21 are substantially parallel to the first leading edge 11a. The antennas 21 have a width W a , and can adopt several forms. Preferably, the antennas 21 have a straight shape with a length La greater than their width W aThe length La of the antenna is related to the RFID frequency used, and it influences several aspects of RFID communication, such as the read range and the overall efficiency of the RFID tag 20. The antennas 21 are separated by a step or a distance d a which is preferably much less than the length La of the antenna 21.

[0077] The antennas 21 of the RFID tags 20 are generally made of conductive materials. These materials are chosen because of their ability to respond to the electromagnetic waves emitted by the RFID reader. The antennas 21 can be made, for example, of copper, aluminum, silver, etc. The antennas 21 can also be made of conductive ink containing metallic particles, produced by printing on the first film 11. As other, non-limiting examples, the antennas can be manufactured by depositing conductive materials onto a substrate or film. These substrates can be, for example, paper, polyamide-based, or other suitable materials.

[0078] As illustrated in Figure 3, a chip 22 is then deposited onto each antenna 21 to form an antenna-chip assembly known as an "inlay" 23 in Anglo-Saxon terminology, or an "insert" in French. Each inlay 23 formed on the first film 11 constitutes an RFID tag

[0079] 20. Chip 22 can preferably be a UHF (Ultra High Frequency) chip, which operates in the ultra-high frequency range, generally between 860 and 960 MHz. UHF chips are better suited to applications where the reading distance exceeds 1 meter, with their range sometimes reaching up to 15 meters depending on the capabilities of the RFID reader. Other types of chips can be used, such as chips compatible with planar antennas on a flexible substrate, such as HF (High Frequency), Bluetooth, or UWB (Ultra-Wideband) antennas.

[0080] The formation of the inlays 23 is generally carried out using "Pick-and-Place" methods, where a first robot 80 grasps a chip 22 and precisely positions it on an antenna 21, according to the design specifications. The arrangement of the antennas 21 in a WEL configuration allows for the acceleration of the inlay formation 23. Indeed, during this inlay formation step, the first film 11 is conveyed to scan all the antennas 21. The direction of travel of the first film 11 is chosen along a direction X perpendicular to the direction Y. Since the antennas 21 are perpendicular to the direction of travel of the first film, the formation of two successive inlays 23 requires scanning the width W a of the antenna and the distance d a between two successive antennas. The sum W a + d a being significantly less than the length L a of the antenna

[0081] 21, the NEL configuration advantageously accelerates the inlay formation stage 23. The distance of a influences the pace of this step. Therefore, it is preferably minimized in order to speed up the process.

[0082] As illustrated in Figure 4, the first film 11 is then cut along the Y direction to form a plurality of formats F. Each format F comprises N inlays 23, N being a positive integer greater than or equal to 2, and less than or equal to 150. Figures 4 and 5 illustrate a particular example in which each format F comprises N=4 inlays 23.

[0083] As illustrated in Figure 5, following the cutting of the first film 11 into F-format, each F-format is rotated 90° around a Z direction perpendicular to the X and Y directions. This rotation of the F-formats allows the transition from a WEL configuration to a NEL configuration. The 90° rotated F-formats are then deposited one by one onto a second upper surface 12b of a second film 12 having a second leading edge 12a, to form a wide strip 30 of inlays 23. At this stage, the inlays 23 of the wide strip 30 extend along the X direction, perpendicular to the second leading edge 12a, i.e., in the NEL configuration. The F formats are deposited successively on the second film 12 so that two inlays 23 of two successive F formats are aligned side by side along the X direction. This makes it possible to form N columns 31 of aligned inlays 23, extending along the wide band 30.

[0084] As illustrated in Figure 6, the wide strip 30 is cut parallel to the columns 31 along the X direction to form M narrow strips 41, 42, where M is a positive integer greater than or equal to 2 and less than or equal to N. Each narrow strip 41, 42 has a leading edge 41a, 42a and includes at least one column 31 of inlays 23 arranged perpendicular to the leading edge 41a, 42a. The excess of the second film 12 on either side of the wide strip 30 along the Y direction can be trimmed to obtain a width W n conforming to narrow bands 41, 42.

[0085] According to a first embodiment illustrated in Figure 6, the wide strip 30 of inlays 23 is cut into M=N narrow strips 41. Each narrow strip 41 comprises a single column 31 of inlays 23, or a single RFID tag 20 per width along the X direction. This narrow strip 41 is said to be "single-strand". Figure 6 illustrates, in an example where N=4, the formation of 4 single-strand narrow strips 41.

[0086] Each RFID tag 20 has a width W e and a length Le. According to the first embodiment, a narrow single-strand strip 41 may preferably have a width W n equal to the width W e of an RFID 20 tag. This allows for a further reduction in width W e of the narrow band 41.

[0087] As illustrated in Figure 7, according to a second embodiment, the wide strip 30 can be cut into M <N bandes étroites 42, comprenant chacune au moins deux colonnes 31 d’inlays 23. Ces bandes étroites 42 dites « multibrins », comprennent chacune selon sa largeur W n Parallel to the Y direction, at least two RFID tags 20. According to this second embodiment, the width W n the narrow multi-strand strip 42 is greater than or preferably equal to the sum of the widths W e at least two RFID tags 20. Figure 7 illustrates an example in which N=4, which makes it possible to obtain, for example, two narrow multi-strand strips 42 each comprising two RFID tags 20 along the Y direction, and having a width Wn=2*W eAccording to another example (not shown), for N=4, a narrow single-strand band 41 and a narrow multi-strand band 42 comprising 3 columns 31 of inlays can be obtained. According to another example, a narrow multi-strand band 42 can comprise up to 150 columns 31 of inlays. Preferably, each narrow multi-strand band 42 can comprise 7 or 8 columns 31 of inlays 23.

[0088] Figure 8 illustrates a longitudinal section of an RFID tag 20 in an XZ plane. According to the example shown in Figure 8, the second film 12, onto which the F formats are deposited after rotation, may include a first sublayer 121 based on an adhesive material. The adhesive material allows the F formats to be fixed to the second upper surface 12b of the second film 12, thus maintaining good alignment of successive F formats during subsequent steps of the process. This first adhesive sublayer 121 may be supported by a second sublayer 122, known as the "carrier" sublayer. The second sublayer 122 is generally based on a non-adhesive material, such as silicone. An RFID tag 20 with a non-adhesive lower surface is known as a "dry inlay."

[0089] The second film 12 may further include a third sublayer 123 based on an adhesive material, underlying the second sublayer 122 or carrier layer. This third adhesive sublayer 123 allows the RFID tag 20 to be attached to a product surface, for example. An RFID tag 20 comprising an adhesive underside, i.e., a third adhesive sublayer 123, is known as a "wet inlay." This type of RFID tag constitutes a finished product ready for application.

[0090] The third adhesive underlayer 123 can be protected by a fourth underlayer 124, known as a "liner" or "release liner," or simply a coating. This fourth underlayer 124 protects the adhesive until the RFID tag 20 is applied to a surface. It is generally designed to be easily removed before the RFID tag 20 is applied.

[0091] The first and third adhesive underlayers 121, 123, can be made of the same adhesive material, or of different adhesive materials with different adhesion properties. For example, the adhesive material of the first underlayer 121 can be permanent, allowing the F-formats to be permanently fixed to the second film 12. The first underlayer 121 can be made of a non-permanent adhesive material, allowing the F-formats or RFID tags 20 to be removed or repositioned without leaving any sticky residue. The third underlayer 123 can be made of a permanent adhesive material, allowing the RFID tag 20 to be affixed to a surface in such a way that it is difficult to remove without damaging the surface.The third underlayer 123 can also be based on a pressure-sensitive, non-permanent adhesive material, allowing the RFID 20 label to be easily removed without damaging the product surface, thus enabling, for example, the RFID 20 label to be reused.

[0092] An adhesive material can be, for example, of the "hot melt" or thermofusible type, which is activated by heat and solidifies upon cooling. This type of adhesive is used for applications requiring rapid adhesion. Thus, the first underlayer 121 can be based on a thermofusible adhesive, for example, one based on Thermoplastic Polyurethane (TPU).

[0093] The process may further include depositing a protective layer 60 onto the inlays 23 of the wideband 30. This protective layer 60 encapsulates the antenna 21 and / or the chip 22 of an RFID tag 20, thereby improving their robustness against mechanical damage, scratches, impacts, and other external aggressions that could impair their operation. The protective layer 60 is configured to at least encapsulate the chip 22, which may have a reduced thickness on the order of one hundred micrometers, for example, around 130 µm. It may also encapsulate part of the antenna 21, or the entire antenna 21, as illustrated in Figure 8. Several protective layers 60 may be superimposed to further improve the robustness of the inlays 23. The protective layer 60 may be based on a plastic material or an epoxy resin. Preferably, the protective layer 60 can be based on an adhesive material.In a non-limiting way, other additional layers not illustrated may be added above inlay 23, or below inlay 23.

[0094] The process may further include a step of laminating the wide strip 30 of inlays 23. Laminating the wide strip 30 of inlays improves the adhesion of the F-shaped inlays to the second film 12. Lamination can be performed under pressure to improve the adhesion of the F-shaped inlays to the second film 12. Lamination can also be performed under heat, particularly when a first underlayer 121 based on a hot-melt adhesive is present, in order to activate the adhesive. It can be performed in the presence of the patient. The F-shaped inlays can also simply be placed in contact with other adhesive materials without the need for heat. Lamination can also be performed after the application of the protective layer 60 to improve its adhesion to the inlays 23.

[0095] Figure 5 illustrates an example in which the F-formats are arranged on the second film so that successive antennas 21 in the same column are separated from each other. Figure 9 illustrates another example, which presents an alternative approach to fixing the F-formats to the second film 12, without necessarily using an adhesive material. In this example, successive F-formats are deposited on the second film 12 so that the antennas 21 in the same column 31 of inlays 23 are in contact, thus forming a continuity between the antennas 21 in the same column 31. Two successive antennas 21 in the same column 31 may, for example, overlap by a few millimeters. According to this example, the process may further include an additional soldering step that allows the antennas 21 brought into contact to be reattached. Preferably, the soldering is carried out ultrasonically.Welding ensures continuity between the inlays 23 of the wide strip 30 without the need for adhesive. This saves adhesive material, thus reducing costs in mass production. The second film 12 can be PET-based. It can also be made of weldable materials (ultrasonic or otherwise), while being relatively insensitive to tensile stress, meaning it has little or no elongation. Furthermore, in this example, the final length of the wide strip 30, and consequently that of a narrow strip, is considerably reduced, improving the compactness of the resulting narrow rolls. This is particularly advantageous for manufacturing single-strand narrow strips 41.

[0096] Figures 10 to 12 illustrate examples of the implementation of the steps in the RFID label manufacturing process 20.

[0097] As illustrated in Figure 10, the inlay formation step 23, by depositing a chip 22 onto each antenna 21, can be carried out using a machine 100 known as a "roll-to-roll" machine. The operating principle of a roll-to-roll machine 100 is based on the continuous processing of a flexible film that is unwound from an initial reel, passes through various processing stages along a feed direction A parallel to the X direction, and is then wound onto a new reel. In the example illustrated in Figure 10, the initial reel corresponds to the first film 11, presenting a plurality of antennas 21 arranged in a WEL configuration, or perpendicular to the feed direction A of the roll-to-roll machine 100.

[0098] The first film 11 is placed on a first unwinding mandrel 131. The first film 11 is then unwound and conveyed along the forward direction A by means of a conveyor system. The conveyor system may include, for example, rollers 110, belts, or other mechanisms to keep the film moving continuously and regularly. It may also include a table 120 placed under vacuum, which keeps the upper surface 11b of the first film 11 in place and flat along its path. As the first film 11 unwinds, a first pick-and-place robot 80 grasps a chip 22 and precisely positions it on an antenna 21, and then on the next one, to form a plurality of inlays 23. The longer the distance d a The smaller the distance separating two successive antennas 21, the faster this inlay formation stage 23. The distance d a can be reduced to as little as 2.5 mm. This distance d aminimal, is wide enough to form an F-shaped edge between two successive antennas without damaging either antenna.

[0099] Once the chips 22 are correctly positioned and fixed onto the antennas 21, the first film 11 of inlays 23 can continue its journey on the vacuum table 120 to undergo further manufacturing steps. As another example, the first film 11 of inlays can be wound onto a second mandrel 132 to form an intermediate reel, which will then be unwound on another machine, for instance. The first film 11 of inlays 23 is then cut along the extension direction of the antennas 21, parallel to the Y direction, to form formats F, preferably having identical dimensions, each comprising N inlays 23. This cutting step, not shown, can be performed mechanically using a cutting tool 103 or with a laser beam.

[0100] Figure 11 illustrates, by way of example, the step of forming the wide strip 30 of inlays. A second film 12 is unwound on a Roll-to-Roll machine 100. The second film 12, comprising a first underlayer 121 based on an adhesive material, passes under a heating element 104, which serves to locally preheat the second upper surface 12b of the second film 12 to activate the adhesive material. The heating element 104 can be, for example, a hot air source or an infrared radiation source.

[0101] Once the second upper surface 12b is activated, it is conveyed to a second robot 81. The second robot 81 rotates each F format by 90°, aligns it, and places it onto the activated second upper surface 12b. The F formats are aligned to form a wide strip 30 with N columns 31 of inlays 23 arranged parallel to the direction of travel of the second film 12. The width of the second film 12 along the Y direction can be greater than or equal to that of the F formats. The excess of the second film 12 on either side of the wide strip 30 along the Y direction can be trimmed later.

[0102] The second robot 81 is advantageously equipped with at least one camera to ensure proper alignment of the F-formats. To improve the accuracy of the F-format alignment, the second film 12 can display registration marks 50. This precise positioning of the F-formats allows, on the one hand, for a regular spacing between two successive F-formats. On the other hand, it allows the antennas 21 of two successive F-formats to be aligned opposite each other, in order to form regular columns 31. The marks 50 can be, for example, registration marks, holes, or centering pins. The second robot 81 can also be a Pick-and-Place robot. The example illustrated in Figure 11 is an example of the fabrication of disjoint inlays that adhere to the second film 12 cold, which are then pressed between two rollers or plates on the second film.According to the example in which the antennas 21 of two successive formats are in contact, the wideband 30 can then be routed to an ultrasonic welder 90, in order to weld the overlapping antennas.

[0103] The wide strip of inlays 30 can then undergo a lamination step. Lamination of the wide strip of inlays 23 can be performed flat by passing the F-formats one after the other under a lamination machine 105. Alternatively, lamination can be performed continuously by conveying the wide strip of inlays 23 between heated rollers. Following lamination, the wide strip can, for example, be wound onto a third mandrel 133 or continue on to another processing step.

[0104] Figure 12 illustrates, by way of example, the step of forming a plurality of narrow strips 41, 42, of RFID tags 20, by cutting the wide strip 30 of inlays 23. The wide strip 30 is unwound onto the third mandrel 133 and conveyed by a Roi l-to-Ro II machine 100 to at least one cutting tool 103 to be cut along the length of the columns 31 parallel to the feed direction A of the machine 100. According to an example not shown, the wide strip 30 can be cut using a laser beam. Separate narrow strips 41, 42 of RFID tags 20 can thus be obtained. Figure 12 illustrates an example in which one multi-strand narrow strip 42 and two single-strand narrow strips 41 are produced. Other combinations are also possible, such as a 42 multi-strand reel with three 20 RFID tags across and a 41 narrow single-strand strip.The narrow strips 41, 42 can then each be wound onto a fourth mandrel 134 to form narrow reels 71, 72. The excess of the second film 12 on either side of the wide strip 30 along the Y direction can also be cut.

[0105] The winding of the narrow strips 41, 42 can be carried out in various ways. The narrow strip 41, 42 can be wound by overlapping, by winding the narrow strip 41, 42 in successive layers one above the other, as illustrated in Figure 1. According to another example illustrated in Figure 13, the narrow strip 41, 42 can be wound by constant pitch cross-winding. In cross-winding, the successive layers of the narrow strip 41, 42 are arranged in a crisscross pattern rather than overlapping. In this winding, the narrow strip 41, 42 is wound around a core or a fourth mandrel 134, forming alternating crossings between the successive layers. By crossing the layers, we reduce the internal stresses of the narrow band 41, 42, which can help to improve dimensional stability and minimize deformations.Thus, cross-winding reduces the mechanical stress on the chips 22 of the RFID tags 20.

[0106] The narrow strips 41, 42, wound into reels 71, 72, are intended to be delivered as finished products. The width W n The width of a narrow band can be between 0.6 mm and 750 mm. The width W e The width of an RFID tag can be between 0.6 mm and 5 mm. The width W a The diameter of an antenna 21 can be between 0.3 mm and 3 mm, preferably equal to 1.5 mm. The length La of an antenna 21 can be between 40 mm and 240 mm, and the length Le of an RFID tag 20 can be between 50 mm and 250 mm.

[0107] In light of the preceding description, it is clear that the proposed process offers a particularly efficient solution for manufacturing narrow RFID label strips in a NEL configuration. This solution is also advantageously compatible with conventional RFID label manufacturing machines.

[0108] The invention is not limited to the embodiments described above and extends to all embodiments covered by the invention. Various specific examples of manufacturing processes and configurations of narrow RFID tag strips have been described. Many other embodiments are possible, for example, by combining previously described features, without departing from the scope of the invention. Furthermore, the features described with respect to one aspect of the invention can be combined with another aspect of the invention. The invention offers various applications in the garment industry for improved inventory management, in the pharmaceutical sector for tracking tubes and syringes, and in the cosmetics industry for products such as eyeliners. It can also be integrated into any industry requiring the use of a thin label.It is important to emphasize that these applications are not limited exclusively to RFID tags, but can also include long and thin sensors, thus expanding the possibilities of use of the process described above.

Claims

Demands 1. A method for manufacturing at least two narrow strips (41, 42) of RFID tags (20) comprising the following steps: • a supply of a first film (11) having a plurality of parallel antennas (21), arranged so that a first principal extension direction of the antennas (21) is parallel to a first leading edge (11a) of the first film (11), • the formation of a plurality of antenna-chip assemblies called "inlays" (23) on the first film (11), by depositing a chip (22) on each of the antennas (21), • a cutting of the first film (11) along the first direction, into a plurality of formats (F), each format (F) comprising N inlays (23), N being a positive integer greater than or equal to 2, the process being characterized in that it further comprises: • a rotation of each format (F) by 90° around a direction normal to the format (F), • the formation of a wide strip (30) of inlays (23), by depositing the formats (F) rotated onto a second film (12), such that a second principal extension direction of the N inlays (23) is perpendicular to a second leading edge (12a) of the wide strip (30), and that the inlays (23) of the successive formats (F) form N columns (31) extending along the wide strip (30), • a cutting of the wide strip (30) parallel to the columns (31) so as to form M narrow strips (41, 42) of RFID tags (20) each having a third leading edge (41a, 42a), M being a positive integer greater than or equal to 2 and less than or equal to N and each RFID tag (20) comprising an inlay (23) perpendicular to the third leading edge (41a, 42a).

2. Method of manufacturing at least two narrow strips (41, 42) of RFID tags (20) according to the preceding claim in which, the deposition of the formats (F) on the second film (12) is configured so that the formats (F) are aligned with each other using patterns (50) present on the second film (12).

3. A method for manufacturing at least two narrow strips (41, 42) of RFID tags (20) according to any one of the preceding claims, wherein the supply of a first film (11) comprising a plurality of parallel antennas (21) is configured such that two successive antennas (21) are separated by a distance d a greater than or equal to 2.5 mm.

4. Method of manufacturing at least two narrow strips (41, 42) of RFID tags (20) according to any one of the preceding claims, wherein the second film (12) on which the formats (F) are deposited after their rotation, comprises a first underlayer (121) based on an adhesive material which allows the fixing of the formats (F).

5. Method of manufacturing at least two narrow strips (41, 42) of RFID tags (20) according to any one of the preceding claims, further comprising a deposit of at least one protective layer (60) on at least the chip (22) of each inlay (23).

6. Method of manufacturing at least two narrow strips (41, 42) of RFID tags (20) according to any one of the preceding claims, further comprising laminating the wide strip (30) with inlays (23).

7. Method of manufacturing at least two narrow strips (41, 42) of RFID tags (20) according to any one of the preceding claims, wherein the deposition of the formats (F) on the second film (12) is configured so that every two successive antennas (21) of the same column (31) of inlays (23) are disjoint.

8. Method of manufacturing at least two narrow strips (41) of RFID tags (20) according to any one of the preceding claims, wherein the cutting of the wide strip (30) is configured so that each narrow strip (41) of RFID tags (20) comprises a single column (31) of inlays (23).

9. Method of manufacturing at least two narrow strips (41) of RFID tags (20) according to the preceding claim, wherein the deposition of the formats (F) on the second film (12) is configured so that every two successive antennas (21) of the same column (31) of inlays (23) overlap, thus forming a continuity between the antennas (21) of the same column (31).

10. Method of manufacturing at least two narrow strips (41) of RFID tags (20) according to the preceding claim, further comprising ultrasonic welding of the overlap areas between the antennas (21) of the same column (31).

11. Method of manufacturing at least two narrow strips (41, 42) of RFID tags (20) according to any one of claims 1 to 7, wherein the cutting of the wide strip (30) of RFID tags (20) is configured so that each narrow strip (42) of RFID tags (20) comprises at least two columns (31) of inlays (23).

12. Method of manufacturing at least two narrow strips (41, 42) of RFID tags (20) according to any one of the preceding claims, further comprising winding each narrow strip (41, 42) of RFID tags to form a narrow reel (71, 72).

13. Method of manufacturing at least two narrow strips (41, 42) of RFID tags (20) according to the preceding claim, wherein the winding of the narrow strips (41, 42) to form narrow reels (71, 72) is carried out by crossing.

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