Patent Description:
RFID tags and labels (collectively referred to herein as "devices") are widely used to associate an object with an identification code. RFID devices generally have a combination of antennae and analog and/or digital electronics, which may include, for example, communications electronics, data memory, and control logic. For example, RFID tags are used in conjunction with retail security systems, security locks in cars, for access control to buildings, and for tracking inventory and parcels. Various examples of RFID tags and labels are known in the art.

Automatic identification of products has become commonplace. For example, the ubiquitous technology used for automatic identification products is RFID. RFID uses labels or "tags" that include electronic components that respond to radio frequency ("RC") commands and signals to provide identification of each tag wirelessly. Generally, RFID tags and labels comprise an integrated circuit ("IC", or chip) attached to an antenna that responds to a reader using radio waves to store and access the information in the chip.

One of the obstacles to more widespread adoption of RFID technology is the cost of RFID tags and difficulties for optimization of economical manufacturing of RFID tags. Increased demand for RFID tags has manufacturers continuously seeking cost reduction and manufacturing simplification and speed. One area for which cost reduction and manufacturing simplification and speed are sought concerns antenna components for RFID devices. Flexible antenna materials such as metallic or metallic containing wires provide many advantageous properties and characteristics, including strength, flexibility and good RF-energy conduction. However, these favorable properties and characteristics are not fully utilized due to the relative slowness and costliness of manufacturing or assembly techniques for transforming flexible materials such as wires into shaped components suitable for antenna use on RFID or other devices. Current methods typically use a dispensing head that moves over a stationary substrate, which methods are relatively slow particularly when compared with other current technology used in methods of making antennas for RFID devices and other devices.

Assembly difficulties tend to increase as RFID chips and their components become smaller. For example, to interconnect the relatively small contact pads on the chips with the antennas, intermediate structures variously referred to as "straps," "interposers," and "carriers" are sometimes used to facilitate manufacture. Interposers for example typically include conductive leads or pads that are electrically coupled to the contact pads of the chips for coupling to the antennas. Depending on intended use or other requirements, antennas will be assembled to or with these types of components.

Document <CIT> describes a method of forming an inlay comprising an antenna wire having two end portions and a site for a transponder chip, comprising the steps of mounting the wire to a surface of substrate; and leaving the end portions of the antenna wire free-standing, as loops adjacent terminal areas of a site on the substrate for the transponder chip. Further, an embedding tool for mounting the wire on the substrate is described.

Document <CIT> describes a method and an apparatus for making radio frequency (RF) inlays.

Document <CIT>describes a wireless communication device coupled to a wave antenna that provides greater increased durability and impedance matching.

Generally, aspects or embodiments of the present disclosure combing using a wire dispenser head moving in one direction to dispense wire and/or other components over a substrate running in a different direction under continuous roll-to-roll process. Such approaches include methods that result in the ability to create antennas at relatively high speeds and relatively low costs.

Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriate manner.

A web of substrate material is generally indicated at <NUM> in <FIG>. This web is provided for the purpose of receiving wire components and serving as the backing or support for structure sized, shaped and configured for use as a component of an RFID device. The web translates in a linear direction of motion as illustrated by the arrow marking <NUM> on <FIG> through the use of a suitable translating mechanism available in the art. This linear direction translation of the web is considered to be along a first directional axis. For example, a roll of web material can be unrolled along a horizontal path as illustrated in <FIG> and collected after receiving added components as discussed herein. Alternatively, the web and added components can move to another processing station. Mechanical support for lateral movement or translation of the web typically is provided in accordance with machinery, devices or structures known in the art such as conveying systems.

This action can be considered to follow a roll-to-roll approach whereby an element (a web in this instance) traverses a path following the first directional axis and receives additions to the web along the path of the web. Typical web materials include cellulosic structures such as paper, fabric or polymers, for example polyesters such as polyethylene terephthalate (PET), or other web suitable materials providing properties needed for the specific function intended for use of the resulting assembly including the web <NUM>.

A dispensing head and its action are schematically shown in <FIG> at <NUM> and by opposing direction arrowhead points <NUM> and <NUM>, with the dispensing head moving along the thus illustrated path between limits such as at <NUM> and <NUM>. In this embodiment, the dispensing head <NUM> can be considered to oscillate between points <NUM> and <NUM> along a pathway having a designated directional axis (second directional axis) that is different from the first directional axis followed by movement of the web <NUM>. As generally illustrated in <FIG>, <FIG> and <FIG>, for example, the dispensing head has an outlet <NUM> in <FIG> that is closely spaced from a surface, such as the illustrated receptor surface <NUM>, of the web <NUM>. The combination of dispensing head action with translational movement of the web provides a "cross-web" motion which "draws" a defined shape of dispensed material (wire) onto the web surface, for example the rounded "saw tooth" shape of wire lengths that are illustrated in <FIG>.

A supply of flexible material that is suitable for use as the antenna-functional material of an antenna, particularly of an antenna for an RFID device such as a passive RFID device, is dispensed by the dispenser by way of the outlet <NUM> of the dispenser head <NUM> of the of the as generally shown in <FIG> or other embodiments. A suitable supply of flexible material is a wire or other flexible conductor material. These flexible conductors or wires are made of antenna-functional material such as metals including copper, aluminum, alloys, solid or braided, coated or uncoated metals, polymers with metal coatings and/or loadings and other materials known in the art for the particular antenna of the intended device such as an RFID device. A useful characteristic of wire material over printed or otherwise applied materials is the flexibility of the typical wire. Using wire for an antenna such as an RFID antenna provides advantages of strength, flexibility and good conductivity of radio-frequency (RF) energy. Such antennas are especially suitable for inclusion in RFID tags. In a typical arrangement, the outlet <NUM> is suitable for passing the wire <NUM> out of the dispenser head; for example, the shape cross-sectional shape of the outlet <NUM> can follow the shape of the wire, typically circular but other shapes are possible. Also, the perimeter of the outlet <NUM> typically is slightly larger than the wire to assist in close placement of the wire onto the web <NUM> without substantial frictional drag on passage of the wire out of the outlet <NUM>.

As illustrated in various embodiments, including that of <FIG>, the web's first directional axis and the dispenser outlet's second directional axis delineate movement in two separate dimensions. In this embodiment, the first and second directional axes are substantially perpendicular to each other. When these diverse movements are combined, the result is formation of non-linearly shaped wire lengths <NUM>. Because the formation of such shapes is achieved by flowing action in multiple dimensions, the formation of the shaped wire lengths <NUM> is according to a high-speed method when compared with other antenna-formation technology. Also, this movement action achieves net relative motion placing the wire onto the web <NUM> in a controlled fashion.

By way of further explanation of the interaction between the movement of the web <NUM> along the first directional axis and movement of the dispenser head along the second directional axis, reference is had to <FIG> as an example of a specific effect possible by this interaction. The antenna configuration is created as the wire transfers from the dispenser head onto the moving web. Using an approximate "sine wave" analogy, the relative movement of the dispenser head while dispensing the wire creates an "amplitude" type of formation along the sine wave, and the relative speed of the web or substrate creates the "period" of the "wavelength" formation along the sine wave. The result of a particular embodiment that does in fact approximate a sine wave pattern is shown in <FIG>.

When it is desired to conserve adhesive and reduce stiffness of the intermediate antenna component, the coated substrate or web <NUM> of <FIG> is replaced with a substrate or web 11a in <FIG> which applies adhesive in only discrete areas along the web. An illustrative embodiment in this regard provides a plurality of patterned adhesive areas <NUM>, which can be printed onto or otherwise positioned on the receptor surface 18a of the web 11a. The positioning of the patterned adhesive areas <NUM> is such that the shaped wire length <NUM> from the dispenser head deposits the wire <NUM> onto the adhesive area <NUM>. In the case where the adhesive areas <NUM> are shaped generally according to the shape of the shaped wire lengths, the adhesive receives the entire pattern of the wire with a reduced adhesive footprint such as avoiding full adhesive placement between adjacent peaks of the wire shape. Alternatively, the adhesive areas can be more simply shaped, for example a rectangle, and positioned along the length of the web such that the adhesive areas <NUM> accommodate all of the shaped wire lengths while allowing more leeway in the degree of exactness in placement of the shaped wire lengths on the adhesive areas during commercial manufacturing.

<FIG> shows an embodiment that interrupts the wire dispensing by any suitable approach in order to place the shaped wire lengths as discrete shaped wire lengths 22a, 22b onto the web <NUM>. Interrupting can be carried out by severing the wire before deposit onto the web, severing being by laser cutting action, by blade cutting action, by heat cutting action, for example. By interrupting before or at the time of deposit onto the web, the flow of antenna components according to this approach does not require severance action after deposit onto the web, but the flow of a plurality of such components is ready for use in the next processing step or steps or as a ready-to-use antenna component such as for an RFID device. In effect, discrete sections 22a, 22b for example of antenna are placed in already-shaped form onto the web <NUM>. In an embodiment, severing can take place within or at the outlet of a dispensing and severing head <NUM> that oscillates in a manner similar to that of dispenser head <NUM>, and between limit points <NUM> and <NUM>.

It will be appreciated that the shaped wire lengths <NUM>, whether provided as discrete wire sections 22a, 22b shaped wire lengths or not, usually will be secured to the web <NUM> to provide a supported antenna or other shaped wire length that is supported for further handling or assembly. Securement can be by action of an adhesive whereby the shaped wire length is deposited onto and onto or with an adhesive in order to hold the shaped wire length in place. Or securement can be by other members and actions. When an adhesive is used, same can be throughout the web receptor surface <NUM> or on only a portion of the web, such as at discrete locations or in discrete patterns. When applied in discrete locations, adhesive printing techniques can be used.

<FIG> illustrates a web assembly containing a web base <NUM> of materials noted herein concerning the substrate or web <NUM>. This embodiment web assembly has a layer of adhesive <NUM> previously applied over the web base <NUM> so the wire is dispensed onto an adhesive surface that is not yet set and thus capable to securing the wire onto the web. As can be seen in <FIG>, when the wire <NUM> is dispensed from the dispenser head <NUM> the wire engages the adhesive in a manner to effectively hold the shaped wire lengths <NUM>, 22a, 22b onto the web. In some embodiments, the shaped wire lengths remain visible above the adhesive layer <NUM>; in other embodiments, the shaped wire lengths <NUM>, 22a, 22b "sink" into the adhesive which is still tacky at that time or that is cured in a manner to hold the wire in place. Details of the interaction between adhesive and shaped wire lengths will vary depending on the type of adhesive and its properties, including its viscosity.

If the shaped wire lengths are fully encapsulated into the adhesive, it may be useful for performance purposes to utilize an adhesive having suitable conductivity properties so avoid interference with desired properties such as those of RFID antenna components. In this <FIG> embodiment, the web base <NUM> is pre-coated with an adhesive such as a pressure sensitive adhesive or hot melt adhesive of types generally known in the art. Whether or not the shaped wire lengths become enveloped in the adhesive will depend on the thickness of the adhesive, its viscosity, the pressure, temperature and other conditions. It will be understood that if the thickness of the adhesive on the web is less than the diameter of the wire, some portion of the wire will be exposed and not fully enveloped.

<FIG> illustrates an adhesive-containing embodiment having a web base <NUM> that is not pre-coated either as presented as the web or at a work station upstream of the wire dispenser. This embodiment dispenses an adhesive onto the web base <NUM> at the same time as the adhesive <NUM> is deposited. The adhesive deposit also can follow the pattern laid out by the combined action of oscillation of the dispenser and flow of the web <NUM>. This embodiment may include a particular dispensing head <NUM> having a dispensing outlet <NUM> that simultaneously accommodates the wire <NUM> and the adhesive <NUM>. This can include having the dispensing outlet <NUM> in engagement with the web base so as to reduce adhesive build up or interference with the movement or flow of the web base <NUM>. Also, the adhesive can be dispensed through the same aperture of the dispensing head <NUM> or through a separate aperture adjacent to the wire dispensing location. The result is a dispensed wire and adhesive combination in the form of adhesive-coated wire shaped lengths <NUM>, which adhesive coating can be full or partial on the shaped wire lengths.

Since the adhesive is essentially extruded with the wire according to this approach, it is very likely the wire will become coated by the adhesive regardless of the amount in contact with the web surface. It can be considered that the <FIG> approach places the adhesive with enhanced efficiency, placing the adhesive where it is needed, reducing stiffness and cost.

The <FIG> embodiment substitutes for adhesive securing or supplements adhesive use with a mechanical system and approach. Shaped wire lengths <NUM> are dispensed onto a web base <NUM> through a suitable dispenser head <NUM>. In this illustration, the mechanical securement is achieved through the use of a plurality of attachment members <NUM> that are applied with the assistance of an applicator <NUM>. When the attachment members <NUM> are stiches or form stiches, the applicator <NUM> is a stitching head, for example. In connection with this embodiment, advantageous securement is enhanced by placing the applicator <NUM> closely downstream in proximity with the dispensing head of the wire dispenser <NUM>.

The embodiments illustrated in <FIG> are relatively simple; either flood coat the web with the adhesive to provide a continuous sheet of adhesive on a web, or present the adhesive in a pattern, typically by printing action, that is effectively an image of the shaped wire to be deposited. This patterned adhesive is more specifically exemplified by the embodiment of <FIG> where the adhesive layer <NUM> is in the form of the adhesive pattern <NUM> along the web 11a of <FIG>.

It can be desired to embed the wire in the adhesive, either fully or partially, to make the shaped wire lengths more resistant to the environment, such as washing, or to mechanical stress detaching the wire from the substrate. If so, the flooding approach that coats the web with adhesive, if done uniformly along all or much of the web, requires more adhesive than if a patterned adhesive approach were used. This increases costs and, especially for fabric applications, reduces flexibility desired for many fabric applications. In this sense, the approach of <FIG> that provides the adhesive patterns <NUM> at a thickness to embed the shaped wire lengths <NUM> both protects the wire well while saving on adhesive cost and improving flexibility when compared with the flooding approach. Concerning the embodiments illustrated in <FIG>, this inherent coating approach protects the shaped wire lengths better than other approaches that may not result in fully encased shaped wire lengths such as flood coating of the web with a thinner layer of adhesive to save cost and enhance flexibility in the final RFID device.

The embodiments illustrated in <FIG> and <FIG> form what might be considered an intermediate component in making an RFID device. These embodiments create antenna components in a system of creating RFID components added at a later stage to manufacture the final RFID device. This is a typical approach for manufacturing RFID tags, and the antenna component is coupled to the RFID element at a later stage, on the same line or a separate line.

According to an alternative approach, the RFID device can be formed in what might be considered a single step, and an embodiment of this approach is illustrated in <FIG> essentially re-orders the process of which embodiments in <FIG> and <FIG> are examples, in that the RFID element is applied first to the web, or is created on the web, and the antenna is formed onto the RFID element. Typical RFID elements are chips, and the approach is suitable for other RFID elements selected according to the end use objectives and specifications.

With specific reference to <FIG>, the shaped wire lengths, dispensed according to the various dispensing embodiments noted herein or others not explicitly disclosed, are dispensed over an RFID element. A series of RFID elements <NUM> are positioned on or applied to the web base <NUM>, or are themselves created on the web. The RFID elements are positional along and spaced on the web so as to be in alignment with the wire dispensing head <NUM> as the RFID element moves to the dispensing head. When the web base <NUM> having a dispensing head <NUM> therealong translates the RFID elements <NUM> to the outlet of the dispensing head <NUM>, shaped wire lengths <NUM> are deposited onto respective RFID elements <NUM> and secured thereto, typically with the assistance of a coupling structure <NUM>. Suitable coupling structures can be those generally known in the art. Such securing is by coupling for forming a series of RFID components <NUM> that include an RFID element such as chip suitably coupled to an antenna and secured to web material.

As will be appreciated by those skilled in the art, the coupling feature can be achieved in various manners. Included are the following. The RFID elements <NUM> may have a coupling structure such as magnetic loops and/or pads <NUM> attached to the RFID elements <NUM>. Coupling between shaped wire lengths <NUM> and the RFID element loops, pads or other coupling structures or interposers can be by magnetic fields, by electric fields, by a combination of both magnetic and electric fields, or by a conductive connection using a conductive adhesive. Alternatively, the shaped wire lengths designed to function as antennas can be welded to the RFID element or an interposer for the RFID element.

Another alternative embodiment is illustrated in <FIG> wherein the wire dispenser has both cross-web and web-directional axis movement, the latter usually to a lesser amount than the cross-web action. Web <NUM> moves in the left-to-right direction as shown by the arrow in <FIG>. Similar to other embodiments, for example that of <FIG>, the dispenser head <NUM> moves according to opposing direction arrowhead points <NUM> and <NUM>, with the dispensing head moving along the thus illustrated cross-web path or directional axis, oscillating given distances between or short of point or points <NUM> and <NUM>. In this embodiment, the dispensing head <NUM> oscillates between points <NUM> and <NUM> along a pathway having a designated directional axis (second directional axis) that is different from movement of the web <NUM> along the first directional axis.

This <FIG> embodiment adds a third directional axis movement partially or fully between arrowhead points <NUM> and <NUM>. When moving toward point <NUM>, the dispenser head <NUM> moves against the direction of web movement, thereby allowing the dispensing wire to move backwards along the web. Usually this movement is for a relatively short distance to achieve limited distance movement essentially defined by the maximum deflection of the head to the point <NUM>. For example, when the dispenser head moves against the web direction for approximately <NUM> along the third directional axis, this combined with the cross-web motion along the second directional axis will dispense shaped wire lengths or antennas with sections where the wire had moved backwards and/or had moved at <NUM> degrees to the web direction, or along the first directional axis, by combining two motions to compensate for the web moving for a limited distance along the third directional axis.

The shaped wire length <NUM> provides an example of the "drawing' of wire shapes that can be achieved with this embodiment. Sections <NUM> which can be considered perpendicular to the web flow along the first directional axis are achieved by movement of the dispenser head <NUM> along the second directional axis while combining the effects of moving toward point <NUM> along the third directional axis while the web continues to move in the opposite direction along the first directional axis. Sections such as at <NUM>, which are generally parallel to the web flow along the first directional axis, are achieved by no or substantially movement of the dispenser head along the second directional axis. Sections such as curves <NUM> can be formed by combination movement along all three directional axes, with movement along the third directional axis is generally in the web direction. What can be considered undercut curve sections <NUM> can be formed by combination movement along all three directional axes, with movement along the third directional axis being generally opposite to the web direction along the first directional axis followed by the web <NUM>.

In a typical embodiment, the first and third directional axes are generally parallel to each other and substantially perpendicular to the second directional axis or cross-web direction. Other embodiments could vary these relationships to achieve particular "drawing" effects, while another embodiment features the first and third directional axes being strictly parallel to each other and each being strictly perpendicular to the second directional axis.

From the above, it will be understood that this mechanism and system allows for flexible manufacture of shaped flexible wire lengths useful as RFID antennas for RFID devices. The method and system achieve these advantageous results in significantly less time than possible using other methods and systems for manufacturing such shaped flexible wire lengths, including on supportive and/or functional webs.

It will be understood that the movements and/or oscillations described herein are capable of being controlled by suitable movement generators and controllers. For example, software can be incorporated in a suitable control system that allows the operator to select among numerous combinations of web flow speed, oscillation speeds and lengths, and combinations of same in order to rapidly form the antennas according to desired shape and size parameters. It is possible to vary such parameters as desired and to provide a flow of antenna components that are shaped as selected, each being consistent in size, shape and quality from antenna component to antenna component according to the selected configuration and parameters.

Claim 1:
An RFID device assembly method, comprising:
selecting a web (<NUM>) having a receptor surface (<NUM>) and translating the web (<NUM>) along a first directional axis under continuous roll-to-roll process to form a translating web (<NUM>);
providing a plurality of RFID elements (<NUM>) positioned on the receptor surface (<NUM>);
providing a dispenser with a dispenser head (<NUM>) and positioning the dispenser head (<NUM>) at a location spaced from the receptor surface of the translating web (<NUM>), the dispenser being associated with a supply of wire (<NUM>);
oscillating the dispenser head (<NUM>) in at least one direction that is along a second directional axis, the second direction being perpendicular to the first directional axis, while dispensing wire (<NUM>) from the supply of wire (<NUM>) through the dispensing head (<NUM>) and onto the web (<NUM>);
said translating of the web (<NUM>), said oscillating of the dispenser head (<NUM>) and said dispensing of wire (<NUM>) combine to deposit a flow of shaped wire lengths (<NUM>) onto the translating web (<NUM>) to form a flow of shaped wire lengths (<NUM>) onto respective RFID elements (<NUM>) on the web receptor surface (<NUM>); and
securing the deposit of shaped wire lengths (<NUM>) onto the web (<NUM>) to form a flow of RFID element and antenna component assemblies as RFID devices.