Method, system and apparatus for making short run radio frequency identification tags and labels

ES 2 646 830 T3

DESCRIPTION

Manufacturing method of conductive structures

The present invention relates to the field of conductive assemblies and to methods for making such assemblies. More specifically, the present invention relates to a method for producing a band of conductive structures. The conductive structures can be used in the production of antennas for RFID circuits, photovoltaic arrays, reflector assemblies, or other constructions.

Conductive laminates such as laminated foils are used in a number of applications ranging from microwave packaging to smart cards. Typically, such laminates are manufactured by punching, stamping, and other mechanical processes that generally lend themselves to high speed situations where a relatively simple shape or pattern can be created.

The increasing demand for circuits has created a need for a manufacturing method that can quickly and efficiently produce such circuits. Such a method is described on one occasion in US Patent Application No.^or2007/0171129 A1. This method includes the steps of providing a reinforced laminated metallic foil, having a layer of the metallic foil bonded to a reinforcing layer, and a carrier layer bonded to the laminated metallic foil. The method includes the step of using a rotary die cutter to cut an antenna pattern through the laminated metal foil to the carrier layer. The method is concluded by removing an unwanted portion of the laminated metal foil matrix to provide a laminated metal foil antenna disposed on the carrier layer.

A rotary die cutter has been used to produce various structures because it is faster and cheaper. However, die cutters have low resolution and are currently limited to having a minimum distance between the cutting lines of approximately 1mm. A further problem with using a die cutter to cut a construction that requires high precision and tolerance is that the cylindrical die used by the rotary die cutter cannot be changed quickly or easily. Consequently, the design is not easily interchangeable, and therefore it is often not economically feasible to produce small batches of a particular design due to the need to constantly change the die heads. Also, any design change would require a long lead time, as a new cylindrical die must be manufactured each time the design is changed. This can lead to a large inventory of die heads, the storage of which can take up valuable factory space.

What is needed, therefore, is an efficient system and method for producing intricate patterns in conductive materials without the above disadvantages associated with conventional cutting devices.

The embodiments of the present invention described below are not intended to be exhaustive or limit the invention to the precise forms described in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art can appreciate and understand the principles and practices of the present invention.

In a preferred embodiment, the present invention is directed to the use of a laser to cut one or more patterns in a conductive layer to create structures that can be further modified for use in a variety of applications, such as radio frequency identification devices. (RFID). An example of a suitable laser for use in the present invention includes a ytterbium laser, which pulses at 48 KHz with a wavelength of approximately 1024 nm. Ideally, the laser energy is not evident at the surface of the substrate. This means that the use of the laser does not cause any damage, discoloration or roughness of the surface.

In the present invention, optical brighteners, or other registration marks or initiators (collectively referred to as registration marks) may be used in cooperation with a pattern or adhesive layer to determine the placement or position of the registration marks to be used in the formation of conductive structures.

In the exemplary embodiment of the present invention, a method is provided for patterning a plurality of registration marks and simultaneously patterning a conductive layer on a pre-patterned adhesive layer. Registration marks are detected by a laser. Once detected, a cutting mechanism is activated that cuts a pattern, or a plurality of patterns, in the conductive layer to form a conductive structure, such as an antenna. In an alternative embodiment to the above, registration marks can be used to place a microprocessor chip which can then in turn be used by the laser cutter at the location of the area to shape the antenna pattern.

In yet another embodiment, a first pattern is provided that can be formed by a die-stamping or cold stamping process, and then subsequently finished by laser cutting more intricate patterns to provide a final pattern.

ES 2 646 830 T3

In one embodiment of the present invention, a conductive intermediate assembly is provided that includes a substrate having a first and a second face. A pattern of an adhesive is provided on the first face of the substrate. A conductive layer, such as a metallic foil, is applied over the adhesive pattern. The conductive layer has at least one first pattern formed in the layer, where the at least one first pattern corresponds to the pattern of the adhesive.

The patterns used in connection with the practice of the present invention can be formed by laser cutting. The laser cutter is controlled by a computer, and in addition to the above, the computer-driven system can be used to create advertising print marks, such as symbols, names, trademarks, logos, manufacturing information, other intricate patterns, and the like. The system can also be used to control a printing or imaging press, such as an ink jet or laser printer, to provide additional printed markings to the substrate on which the conductive structure has been formed. Thus, a complete system is provided having a relatively small footprint for generating small batches or quantities of custom materials such as hangtags, tickets, labels, and the like.

Other features and advantages of the present invention will be apparent to those skilled in the art from the following detailed description. It is to be understood, however, that the detailed description of the various specific embodiments and examples, while indicating preferred embodiments and other embodiments of the present invention, are provided by way of illustration and not by way of limitation.

These, in addition to other objects and advantages of this invention, will be more fully understood and appreciated with reference to the following more detailed description of the presently preferred embodiments of the invention, in conjunction with the accompanying drawings, of which:

FIGURE 1 represents a cross section of the web produced in accordance with the present invention before patterning;

FIGURE 1A shows an example of a conductive structure produced in accordance with the present invention; FIGURE 2 depicts a partial selection of a strip after patterning by a cutting mechanism having a plurality of conductive laminates disposed on the surface of the strip; FIGURE 3 illustrates a methodology for creating the conductive structures of the present invention;

FIGURE 4 is a schematic view showing the process for creating the band depicted in FIGURE 1;

FIGURE 5 depicts a roll-to-roll process for manufacturing a standard conductive structure in accordance with one aspect of the present invention; and FIGURE 6 provides a substrate produced in accordance with the present invention.

The present invention is now illustrated in greater detail by the following detailed description, which represents the best currently known mode of carrying out the invention. However, it should be understood that this description is not to be used to limit the present invention, but is instead provided for the purpose of illustrating the general features of the invention.

The present invention relates to a unique and efficient method for producing intermediate assemblies that can be used in the creation of circuits, antennas, photovoltaic modules and other specialized intricately shaped conductive structures. The present invention provides a method in which registration marks are used for the purpose of aligning a laser cutter, and a pattern so that at least one conductive structure can be formed in a conductive material. The present invention also describes the use of optical brighteners as registration marks, or in addition to registration marks, to indicate the placement of conductive structures.

Registration mark printing and adhesive coating may also take place simultaneously, substantially simultaneously, or sequentially in order to rapidly and efficiently produce conductive structures in accordance with the present invention.

The present invention may additionally, or alternatively, utilize the registration marks for placement of a microprocessor chip prior to commencement of ablation or laser cutting (see FIGURE 1A). In this embodiment, the laser can use the chip as a registration mark to guide the laser in cutting the conductive pattern in the thin sheet layer.

FIGURE 1 illustrates a cross-sectional view of web 10 to be produced in accordance with the present invention. A substrate 11 with a first face 13 and a second face 15 has an adhesive layer 20 provided on at least a section of the first face 13 of the substrate 11. The adhesive layer 20 in one embodiment is provided in a pattern that will correspond to the shape of the conductive structure to be formed into the conductive foil or laminate (see FIGURE 1A). A conductive layer 120 is then provided over adhesive layer 20. Conductive or thin sheet layer 120 adheres only to those areas of the adhesive that

ES 2 646 830 T3 are provided in the form of a pattern. That is, some sections of the thin sheet layer will not be attached to the substrate, while other sections, due to the patterning of the adhesive, will adhere to the substrate. The pattern of the adhesive can be seen, for example, ending at line 17 in FIGURE 1, such that a portion of the thin sheet 120 does not adhere to the substrate 11, indicated by the non-adhesive area 121. An example of a conductive pattern 50 is shown in FIGURE 1A. The conductive pattern 50 has an area 55 that can be used to attach a microprocessor chip or tape to the formed structure.

As used herein, the term "conductive layer" can include a thin metallic foil layer or a thin metallic foil combined with one or more additional layers such as a backing layer, a carrier layer, adhesive, layer of cover or the like.

The substrate 11 can be made of any material or combination of materials that allows the substrate 11 to be flexible to facilitate the manufacture of the substrate 11 as a continuous web that can be wound into a roll for use in a roll-to-roll process ( see FIGURES 4 and 5). Examples of such substrate materials include, but are not limited to, polyester films, polyethylene terephthalate films, polyimide films, fabrics (woven, nonwovens, synthetics, natural), fabrics or paper materials (cardstock, paper bond, recycled paper, etc.).

It should be understood that while the present invention is described as a roll-to-roll arrangement utilizing a web, the invention may be practiced in a sheet feed configuration, in which a stack of sheets of material is used as the supply. of the starting material.

Conductive layer 120 can be made of any conductive material, such as aluminum, copper, silver, gold, metal alloys, and the like. Combinations of conductive materials can be used. In addition, the conductive material can be created by printing conductive ink, etching, or other suitable processes.

The adhesive layer may be a general purpose permanent pressure sensitive adhesive, a pressure activated adhesive, or another suitable adhesive. The adhesive layer can be applied to the substrate by coating with or printing a pattern, such as flexographic ink jet printing, integral coating, or other suitable method.

Reference is now made to FIGURE 2 which shows a web 10 to be produced in accordance with the present invention after patterning by a cutting mechanism, such as a laser. A band 10 is provided having a number of conductive structures 22 provided on the upper surface 12 of band 10, after the remaining matrix, the unconnected sections of the conductive foil, has been removed. To form the conductive structure 22, the web 10 was provided with a series of registration marks 14 along one of the first and second lateral edges 16 and 18 of the web extending longitudinally over the adhesive (no show). It should be understood that registration marks may be provided along both sides or edges of the substrate, or at other locations on the substrate.

The registration marks 14 may further be provided in one embodiment on the first face 13 of the substrate 11, prior to the coating of the adhesive on the first face 13 of the substrate 11, provided that a transparent adhesive coating layer is used to allow detection of registration marks 14. That is, the clear coating, if applied over the markings, would allow the markings to be visible, such as by a scan by a machine vision system, through the coating. The registration marks 14 assist in the alignment of the conductive structures 22 and are modeled by a printer. Typically, the registration marks 14 are provided in a machine direction which is the direction in which the web or sheets travel through the machine. The registration marks may be provided with optical brighteners to facilitate the detection of the marks.

FIGURE 3 provides a block diagram for an exemplary method for creating a plurality of conductive structures 22 on a web 10 in accordance with the present invention, applying a plurality of registration marks 14 and at least one conductive pattern 24. In step 300, a substrate 11 is provided having a first and a second face. An adhesive layer 20 (shown in broken lines and not covered by conductive layer 22 for the purpose of illustration) is provided on the first face 13 of the substrate 11. An adhesive layer 20 is provided on the first face 13 of the substrate 11 by flow coating. A series of registration marks are also printed on the first side of the substrate. A conductive layer 120 (see FIGURE 1) is provided over adhesive layer 20.

The areas of the adhesive corresponding to the patterns to be formed are desensitized in step 310 where conductive structures are not to be formed. In step 301, certain areas of the adhesive layer are "desensitized", by a UV source or a printing varnish (not shown). As a result, the adhesive layer 20 will have separate areas designated as "desensitized" and "active." An active area of ​​the adhesive will maintain its tack and allow the thin or conductive sheet layer to adhere to the adhesive, while a desensitized area loses its tack and the thin sheet or conductive layer will not adhere to the adhesive.

ES 2 646 830 T3

By desensitizing certain areas of the adhesive layer 20, specifically, those areas 21 around the locations where the conductive structures 22 are to be formed by the active areas of the adhesive layer 20, will be substantially surrounded by the desensitized adhesive. A cutting tool is used to cut the patterns 24 in the conductive layer 120 for a conductive structure 22. In a preferred embodiment, the cutting mechanism is a laser. It should be understood, however, that the cutting pattern 24 can be achieved using other cutting devices, which may pre-cut a section of the pattern prior to laser cutting of more intricate patterns.

In step 320 the conductive layer is laminated or adhered to those sections of the adhesive that remain adherent. At step 330, a plurality of patterns are cut into the conductive layer to form a plurality of conductive structures.

Excess conductive layer 120 material that is provided over the desensitized areas of adhesive layer 20 is removed by removing the remaining matrix of conductive layer 120 from the desensitized areas of adhesive layer 20. It should be noted that the matrix, particularly if a thin metal foil is used, it is 100% recyclable.

In one embodiment of the present invention, optical brighteners 23 are used in cooperation with registration marks to activate the cutting mechanism to cut at least one pattern 24 in conductive layer 120 for conductive structure 22. Optical brighteners 23 may be provided in or around the area of ​​the registration marks 14, which is along the marginal or lateral areas to activate the laser to begin cutting the conductive substrates. In one embodiment, optical brighteners 23 may be mixed into the pattern of the adhesive layer 20. In another embodiment, a pattern of optical brighteners 23 may also be printed on top of the pattern of the adhesive layer 20 rather than being mixed into the adhesive layer 20 itself. In another embodiment, a specific pattern of optical brighteners 23 can be printed on the first face 13 of the substrate 11 before the adhesive layer 20 is provided on the first layer 13 of the substrate 11, then a transparent or at least partially transparent adhesive, it is applied to the substrate so that the optical brighteners 23 are visible through the adhesive layer 20 and can be recognized by the cutting apparatus.

Additional optical brighteners 23 may also be provided in a particular shape or around the area in which the conductive structure 22 is to be shaped, so that complementary laser cutting can take place, such as cutting of areas to form the section of chip placement or bonding.

Optical brighteners 23 may be provided in the form of a specific pattern, such as columns, and / or rows with certain geometric shapes to activate the cutting mechanism to cut a pattern at each location of an optical brightener registration mark for a conductive structure 22 in conductive layer 120. The conductive layer 120 when over the adhesive layer 20 does not cover the area occupied by the registration marks 14 and / or optical brighteners 23 to allow the cutting mechanism to detect the registration marks to align the plurality of conductive structures with registration marks. When the optical brighteners 23 are used as registration marks 14, it is possible to model the adhesive 20 and the registration marks 14 simultaneously, thus providing a more efficient method by reducing the number of steps required to construct the conductive structures.

The registration marks 14 can be printed using a wide variety of inks on each individual optical brightener 23. In an alternative embodiment, the registration marks 14 of the present invention may further be created from sections of the conductive layer or fragments of thin-foil laminates that are placed in a particular area to be detected by the scanning device. cut.

In an exemplary embodiment, the optical brighteners 23 are a fluorescent powder, approximately 1% of the total weight of the adhesive pattern and more preferably the fluorescent powder comprises 5% of the total weight of the adhesive. The optical brighteners 23 and the adhesive layer 20 can be created from the same plates and printing blanket so that the optical brighteners 23 and the adhesive pattern 20 are generated simultaneously. In other embodiments of the present invention, the optical brighteners 23 may have a unique fluorescent powder color or may include UV-detectable elements.

Conductive layer 120 has at least one pattern 24 corresponding to at least one section of adhesive layer 20. The present invention contemplates the possibility of a plurality of patterns, ie patterns produced in a single or multiple lines. The cutter can be used to create an additional area for the attachment of an integrated circuit, and to finish the cut of additional patterns to add some variability to the design. With regard to the placement of the chip, tapes can be placed on the thin sheet that are to facilitate the alignment of the chip so that it is more easily connected to an attachment point. The bonding pattern 24 is approximately 100 microns wide.

In another embodiment, a further pattern may be produced in another area of ​​the conductive layer to form a barcode, company logo, or some other variable printed data or marks.

ES 2 646 830 T3

Attention is now directed to Figure 4 which provides a possible scheme for producing web 10 as illustrated in FIGURE 1. The web of material, such as paper, plastic, cloth or fabric, is unwound from a roll 30. A printer 32 can be used to apply the registration marks to the web for subsequent scanning by the adhesive coating and cutting stations. An adhesive applicator 34 applies the adhesive as a full coating of the web. Next, a UV source 36 is directed onto the adhesive to desensitize selected areas of the adhesive, those areas outside the areas corresponding to the patterns to be created in the conductive layer, leaving active areas where conductive structures 22 will be. conformed. A roll 40 laminates a conductive layer 38, such as a thin sheet that is fed from a strong unwound 37 to the active areas of the adhesive coated web 10. A pattern 24 is cut by a laser cutter 42 into the conductive layer. It should be noted that the laser energy does not nick or mark the underlying substrate band.

Once the pattern 24 is cut into the conductive layer or thin sheet 38, the remaining sections of the conductive layer that are not in contact with the active areas of the adhesive layer are removed by a stripper 44 and rewinder 46. The Collected material, for example a thin sheet, is 100% recyclable because the thin sheet has not been contaminated with the adhesive, since the adhesive has been desensitized before its application. Band 10 is rewound at 48. The web 10 after forming the individual conductive structure or laminated sheet 22, can be sent through the cutter (not shown), to separate the conductive structures or laminated sheets from each other, or the web can be collected and cut at a later time. Strip 10 may further undergo a second or third or more cuts depending on the particular end use to be made of the conductive substrate.

The laser cutter 42 can further cut marks printed on the thin sheet, such as trademarks, trade names, logos or other information in a separate area to add some variability and personalization to the web as will be described herein.

A further schematic illustration of a roll-to-roll process by which a web 10 of conductive structures 22 can be created is illustrated in FIGURE 5. A web 90 is dispensed by an unwinder 95 from a web roll 100 and fed to a first cutting station, for example a laser, a rotary cutter or a cold stamping roll or a die 100 having a rotating die 150 if the station is a stamping or cold stamping unit. The first cutter can be used to remove large segments of material from the conductive structure to be shaped. Web 90 exits a first cutter 110, and is fed to a laser cutter 175. A laser cut path 215 is programmed into a computer 177 that controls laser cutter 175. The computer controlled cutter can do all the cutting that is needed or can alternatively be reserved for cutting more intricate patterns or for any finishing cut.

Continuing with FIGURE 5, web 155 exits laser cutter 175 and is fed to separator 180, if necessary. When provided, the spacer 180 separates the matrix band or the remaining conductive material or thin sheet 190 from the shaped conductive structures 22 to create a band 185 of conductive structures. The band 185 of conductive structures has a succession of structures 22 disposed on a carrier layer 185. The conductive structure web 185 is wound onto a roll 195 by a first rewinder 200, while the die web 190 is wound onto a die roll 210 by a second rewinder 205.

Reference is now made to FIGURE 6, which includes a substrate 400, having a first part 410 and a second part 420. The first part 410 is provided with a conductive structure 430 such as an RFID device / antenna and the second part 420 it is endowed with printed 440 trademarks such as the retailer's name, logo or other information such as trademarks, trade names, designs, patterns or the like. Each of the 430 conductive structures and printed markings is produced by laser cutting.

Substrate 400 may further include first and second sections 440, 450, respectively. The first section 440, is composed of the first and second parts 410, 420, respectively, and the second section 450 can be folded over the first section 440 along a fold line 455 to form one of a hang tag, ticket, label or similar. The second section 450 may further be provided with printed markings 460 which may refer to the consumer product to which the substrate is attached in the form of a hang tag, for example.

It will be appreciated, therefore, in accordance with the present invention, that a highly advantageous method of manufacturing a conductive substrate has been provided. While the invention has been described in connection with what is presently considered the most practical and preferred embodiment, it will be apparent to those skilled in the art that the invention is not to be limited to the described embodiment, and that many modifications and equivalent arrangements of they can be carried out within the scope of the invention, the scope of which will be in accordance with the broadest interpretation of the appended claims to encompass all equivalent structures and products.

ES 2 646 830 T3

Reference is now made to FIGURE 6, which includes a substrate 400, having a first part 410 and a second part 420. The first part 410 is provided with a conductive structure 430 such as an RFID device / antenna and the second part 420 it is endowed with printed 440 trademarks such as the retailer's name, logo or other information such as trademarks, trade names, designs, patterns or the like. Each of the 430 conductive structures and printed markings is produced by laser cutting.

Substrate 400 may further include first and second sections 440, 450, respectively. The first section 440 is composed of the first and second parts 410, 420, respectively, and the second section 450 can be folded over the first section 440 along a fold line 455 to form one of a hangtag, ticket, label or similar. The second section 450 may also be provided with imprinted markings 460 which may refer to the consumer product to which the substrate is attached in the form of a hang tag, for example.

It will therefore be appreciated, in accordance with the present invention, that a highly advantageous method of manufacturing a conductive substrate has been provided. While the invention has been described in connection with what is presently considered the most practical and preferred embodiment, it will be apparent to those skilled in the art that the invention is not to be limited to the described embodiment, and that many modifications and equivalent arrangements of they can be carried out within the scope of the invention, the scope of which will be in accordance with the broadest interpretation of the appended claims to encompass all equivalent structures and products.

The inventors hereby declare their intention to rely on the Doctrine of Equivalents to determine and evaluate the reasonably fair scope of their invention, since it pertains to any apparatus, method or article that does not materially depart from, but is outside the literal scope of the invention as set forth in the following claims.