Patent Description:
While various combinations of metal and glass layers in transaction cards have been disclosed, such as in <CIT>, the combination of metal and glass provides unique opportunities for new constructions to meet the continued desire in the field for metal-containing cards with unique aesthetics and maximized operability in contactless mode.

<CIT> discloses the preamble of claim <NUM> and illustrates for example a secured holographic magnetic tape comprising a magnetic layer for encoding data, an embossable layer for embossing a hologram, and a metal layer. The metal layer comprises a plurality of sections forming a pattern based on a predetermined magnetic signature of the tape.

Further advantageous embodiments are defined in the dependent claims.

Referring now to <FIG>, portion <NUM> of a transaction card comprises a substrate <NUM>, a discontinuous metal stratum <NUM> comprising a plurality of isolated features <NUM>, and a transaction module <NUM>. As referred to herein, the transaction module may be any module configured for conducting any type of transaction, capable of contact-only, contactless-only, or dual interface (contact and contactless) interaction with a card reader, and in particular a transaction module configured for conducting financial transactions (sometimes referred to as a "payment module"), such as are commonly found in credit cards, debit cards, and the like. Contactless modules typically use radio frequency (RF) communications and comprise radio frequency identification (RFID) integrated circuits that operate in compliance with the ISO/IEC <NUM> international standard for contactless smart card communications. The invention is not limited to any particular type of transaction card, or transaction module, however.

Substrate <NUM> is preferably a glass layer, such as but not limited to a flexible or conformable glass, such as an aluminosilicate, borosilicate, boro-aluminosilicate glass, sapphire glass, or ion-exchange-strengthened glass. Numerous examples of such flexible or conformable glasses are known in the art, and are favored for their shatter-resistant properties and strength. Such glasses are also denser than traditional plastic layers found in some transaction cards, and therefore lend additional heft or weight to the overall look and feel of a card. Although preferred embodiments comprise flexible or conformable glass compositions, the term "glass" as used herein refers to any material having any non-polymeric chemical composition (i.e. non-plastic), typically inorganic, and typically containing SiO2 as a primary component, that is transparent or semi-transparent, including amorphous non-crystalline compounds as well as crystalline compounds, sometimes also referred to as "crystal. " Additionally, acceptable glass layers may include glass varieties known as "safety glass," including laminated glass (comprising one or more layers each of glass and plastic, typically held together by an interlayer), toughened (tempered) glass and engraved glass. While glass layers having transparency or semi-transparency may have certain advantages, embodiments of the invention may include embodiments with cores comprising other non-metal or non-plastic materials (e.g. ceramic) that are opaque or only translucent. Although depicted as a monolithic layer, the core layer may comprise a composite of multiple material layers, including multiple glass layers of the same or different types of glass.

Discontinuous metal stratum <NUM> is preferably comprises a plurality of isolated metal features <NUM>. The term "stratum" is used herein consistent with the Latin meaning of something "spread or laid down," to reflect that in at least some embodiments, the isolated metal features do not form a contiguous layer in the same way as a bulk metal layer or foil layer. In other embodiments, disclosed herein later, however, the discontinuous metal stratum may indeed comprise a layer with an adequate amount of electrical eddy current disruption between adjacent metal regions, but may form a contiguous layer. In some embodiments, the isolated metal features are isolated from the moment of formation, whereas in others, a metal layer may be processed to create the electrical eddy current disruption between features, which may comprise a distance of empty space that provides isolation.

Suitable metals for the metal stratum may include aluminum, silver, copper, gold, rhodium, tungsten, titanium and alloys of the foregoing, including alloys that contain nonmetallic elements (e.g. titanium nitride), including non-metallic elements for creating a desired color effect, but the invention is not limited to any particular metal or metal alloy. For example, numerous colored surface coatings in different colors may be obtained, e.g., via PVD, such as: gold (TiN), rose gold (ZrN), bronze (TiAlN), blue (TiAlN), black (TiAlCN), as well as a dark red (ZrN). The metal features may also or instead be heat treated to obtain a desired color. Although depicted as having a round cross section, it should be understood that the features may have any cross section. Likewise, while depicted as having a frustoconical shape in longitudinal section, the features may have any geometry in longitudinal section, including hemispherical, and having round or flat tops. The term "isolated" is intended to mean that each metal feature is separated from adjacent metal features by at least a predetermined minimum distance "d" as depicted in <FIG>. Preferably, the predetermined minimum distance between adjacent features is a distance calculated to avoid bridging of energy between adjacent halftone dots in the presence of less than a predetermined level of energy. In embodiments in which the metal features are not isolated, the features otherwise have a sufficient degree of electrical eddy current disruption relative to one another to avoid syncing of eddy currents of adjacent metal regions at the predetermined level of energy in a way that disrupts the communications for processing the transaction at a desired distance between the card and the card reader. The predetermined energy level may coincide with the typical maximum rated field strength of a contactless transaction card reader. For example, the typical energy density found in a Point of Service (POS) terminal for contactless processing a transaction card at the extremes may include a range of <NUM> - <NUM> A/m<NUM> (amperes per square meter).

The plurality of isolated metal features in the discontinuous metal stratum preferably form a halftone pattern. The halftone pattern may be defined by the plurality of metal features evenly distributed across the surface of the card, or the plurality of metal features may have an uneven distribution, wherein the uneven distribution forms a halftone image. As is known in the art, halftone is a technique that uses a plurality of dots so small and spaced so closely together that the human eye interprets the plurality of dots as a continuous-tone. The size and/or spacing of the halftone dots may also be varied to generate a gradient-like effect between light tones and dark tones. Halftoning is typically used as a reprographic technique, such as in the field of printing, in which the gradient of tones between light and dark may be used to form grayscale images. Likewise, combinations of grayscale images printed with different color inks (e.g. Cyan, Yellow, Magenta and black in a CYMK color scheme) in halftone patterns may be combined to form full color printed content. In traditional printing, the gradient between light and dark may span from lighter tones in which each printed "dot" is isolated from each adjacent dot, to darker tones in which the printed dots are so close together that the adjacent dots of ink connect to one another with holes comprising the absence of ink being isolated from one another. In embodiments of the invention in which isolation between the metal features is essential to minimize effects caused by the metal stratum on RF communications, a majority or at least substantial portions of metal features preferably conform a metallization pattern in which each "dot" in the halftone pattern is isolated from adjacent dots. However, in embodiments in which gradients in tone are combined to create a visual image, at least some portions of the halftone image may comprise portions of the metallization pattern in which some of the halftone dots connect to another other. In general, however, the metallization pattern is disposed to avoid creating a continuous path of metal within at least select areas of the card, and preferably between an edge of the card and the periphery of the payment module. A combination of a halftone pattern of discrete metal features in one area, and discontinuities in a bulk or foil metal in another area, may also be provided.

The metal features may be deposited by any method known in the art, including but not limited to physical or chemical vapor deposition processes by which the dots are created directly on the glass substrate, deposition of a solid layer or a foil on the substrate and etching away metal from the between the remaining features, or printing, such as using inkjet, lithographic, or additive manufacturing (i.e. 3D printing) processes. For example, in one embodiment, a photoresist may be disposed on the substrate, exposed through a mask with actinic radiation (e.g. UV) to cure the exposed portions of the photoresist, and the uncured portions removed. Then, the metal may be deposited using a deposition process (e.g. CVD or PVD) that creates the metal features on the substrate in the areas where there is no photoresist, and deposits the metal on the photoresist where the photoresist remains. The photoresist is then removed, leaving the metal features. In the foregoing, the mask is a negative mask that allows the actinic radiation through holes in the mask that coincide to the spaces between the metal features, so that the cured photoresist remains on the substrate in the areas where it is not desired to deposit the metal features. In another process, a continuous metal layer is disposed on the substrate, such as with a PVD or CVD process, a photoresist deposited over the metal layer, and the resist exposed to actinic radiation through a positive mask that has holes corresponding to the metal features. The uncured photoresist is removed, and an etching process is conducted, which etches away the metal in the areas not protected by the photoresist. The photoresist is then removed, leaving the metal features, In still other embodiments, the metal features may be formed from continuous solid metal layer, and unwanted portions of the metal removed by focused energy, such as a laser or an e-beam (focused electron beam), leaving only the metal features. In still other embodiments, the metal features may be formed by metal particles contained in a curable or sinterable resin. In another embodiment, dot-shaped or wire-like metal nanostructures may be prepared in an array as a self-assembled monolayer on a diblock copolymer template, as described in <NPL>).

Although embodiments with isolated metal features have been primarily described, it should be understood that inverse designs may also provide sufficient electrical eddy current disruption between metal regions to permit sufficient RF transmissivity through the discontinuous metal stratum. For example, as shown in <FIG>, an array of holes <NUM> in metal layer <NUM> may be coupled with one or more elongated discontinuities or slits, such as one or more lines <NUM>, one or more of which preferably extends to a periphery of the card or which is in communication with a non-metal area that extends to the periphery of the card. Multi-slit designs in a metal layer are described, generally in <CIT>, titled "DI METAL TRANSACTION DEVICES AND PROCESSES FOR THE MANUFACTURE THEREOF". In another embodiment that provides open space between metal features in which at least some of the open space is isolated from and not in communication with adjacent open space, a micro- or nano-mesh may be prepared and bonded to the substrate. Such metal mesh patterns may also benefit from the use of multiple slits or elongated discontinuities to break up metal regions that would otherwise form interconnected metal regions, and eddy currents associated therewith, extending across a relatively large portion of the card.

It should be understood that although in some embodiments card portion <NUM> may comprise a freestanding card without more, in other embodiments portion <NUM> may include one or more additional decorative or functional layers not depicted in <FIG>, including printed layers, protective layers, and layers containing other functional or aesthetic features common to transaction cards, including but not limited to security features such as holograms, codes (such as bar codes or QR codes), magnetic stripes, signature blocks, printed layers, embossed layers, embedded electronics, and the like. Methods for embedding electronics in cards, generally, are described in <CIT>, published under <CIT>, and related applications to which priority is claimed or that claim priority therefrom. Additional layers may also include one or more of: a printed ink layer, a laminated layer, a laser patterned layer, a coated layer, a photolithographic layer, a printed OLED layer, or a vacuum deposited layer. The relative sizes of the various features as depicted in <FIG> (and in any of the figures herein depicted) are not intended to be to scale.

Referring now to <FIG>, a card embodiment is depicted comprising card portion <NUM>, comprising first glass layer <NUM>, discontinuous metal stratum <NUM> disposed on one surface of glass layer <NUM>, and a metallized antenna <NUM> disposed on the opposite surface of the glass layer. Transaction module <NUM> is disposed in the first glass layer <NUM>. In other embodiments, additional decorative or functional layers may be present in any portion of the stack, such as a protective coating <NUM> (preferably clear) over the metallized antenna <NUM>, such as UV- or thermally-cured polymeric compounds, sometimes referred to as potting compounds. The metallized booster antenna <NUM> may be transparent, such as formed from indium tin oxide (ITO). The metallized antenna <NUM> may be created by any method known in the art, including deposition of a continuous metal stratum on the glass surface, and etching away portions of the metal to leave the desired antenna structure. The booster antenna <NUM> inductively couples with or is physically electrically connected to the transaction module <NUM> to improve communication performance.

Referring now to <FIG>, a card embodiment <NUM> is depicted having a first glass layer <NUM>, a discontinuous metal stratum <NUM> as described above, and a second glass layer <NUM>, with a transaction module <NUM> disposed in the first glass layer <NUM>. The metal stratum <NUM> is disposed on the first glass layer <NUM> between the first glass layer <NUM> and the second glass layer <NUM>. This location of the discontinuous metal stratum <NUM> as an inner stratum sandwiched between outer layers of glass layers <NUM>, <NUM> protects the metal stratum <NUM> from wear and tear. In other embodiments, additional decorative or functional layers may be present in any portion of the stack. Although the transaction module <NUM> is depicted as disposed entirely in the first glass layer <NUM>, other embodiments may include the transaction module <NUM> extending through the discontinuous metal stratum <NUM> into the second glass layer <NUM>. While the transaction module <NUM> is depicted as having a top surface flush with an outer surface of the card <NUM>, such as is typical for contact or dual interface modules, a contactless-only module may be disposed entirely beneath the top surface of the card <NUM>. Exemplary cards having the designs as described herein may include cards with transaction modules that are contact only, contactless only, or dual interface (DI).

Referring now to <FIG>, card embodiment <NUM> has a first glass layer <NUM>, a discontinuous metal stratum <NUM> as described above, a protective layer <NUM>, and a transaction module <NUM> disposed in the first glass layer <NUM> with a top surface flush with the top surface of the protective layer <NUM>. The protective layer <NUM> as depicted fills gaps between the metal features <NUM> and is disposed over the discontinuous metal stratum <NUM>. It should be understood that in some embodiments, the protective layer <NUM> may fill gaps between the metal features <NUM> but not extend as a covering over the discontinuous metal stratum <NUM>, and in other embodiments, the protective layer <NUM> may extend over the discontinuous metal stratum <NUM> but not between the metal features <NUM>. In still other embodiments, the protective layer <NUM> may only partially fill gaps between the metal features <NUM>. Protective layer <NUM> is preferably a non-metal layer that acts as an electrical isolator and insulator, and the effects of the isolation and insulation may enable a smaller spacing between features with less interference with RF communications than without the isolation / insulation layer. In other embodiments, additional decorative or functional layers may be present in any portion of the stack. To the extent necessary or desired, the protective layer <NUM> may comprise an IR-blocking compound, particularly in any implementations that benefit from such a blocker in order to confirm to card ATM standards. For example, the embodiment depicted in <FIG> may include a metallized antenna layer as depicted in <FIG>, with or without a protective layer <NUM> over the metallized antenna layer.

Referring now to <FIG>, card embodiment <NUM> includes a first glass layer <NUM>, a discontinuous metal stratum <NUM>, a payment module <NUM> disposed in the first glass layer <NUM>, a second glass layer <NUM>, and a metallized antenna layer <NUM> disposed over the second glass layer <NUM>. The discontinuous metal stratum <NUM> and the metallized antenna <NUM> are both disposed on the inner surfaces of the respective first and second glass layers <NUM>, <NUM> facing one another, and may include a non-metal layer <NUM> (e.g. a PVC, PET, or other polymer layer and/or an adhesive layer) disposed between the discontinuous metal stratum <NUM> and the metallized antenna <NUM> to insulate and isolate the antenna layer <NUM> from the discontinuous metal stratum <NUM>. Layer <NUM>, on the outer surface of the second glass layer <NUM> may comprise a printed ink layer, a laminated layer, a laser patterned layer, a coated layer, a photolithographic layer, a printed OLED layer, or a vacuum-deposited layer. Additional decorative or functional layers may also be present in any portion of the stack. In some embodiments, the laminated layer may be a metal layer, preferably an RF invisible or nearly invisible metal layer, such as an otherwise continuous metal layer having one or more discontinuities in the nature of elongated slits, as described in <CIT>, referenced above.

Although not limited to any particular constructions, the metal features <NUM> are preferably disposed on the glass layer with a density of at least <NUM> dots per inch (DPI) (<NUM> dots per centimeter (dpcm)), and may be in a range of the current technical upper limit of e-beam lithography, and more preferably in a range of <NUM>-<NUM> DPI (<NUM>-<NUM> dpcm), in embodiments in which the halftone pattern is intended to give the discontinuous layer an opaque visual appearance. Notably, the term DPI (or dpcm) typically relates to the number of dots per unit of linear horizontal measure, whereas LPI (or lines per inch) typically relates to the number of horizontal lines per unit of linear vertical measure in printing processes. Many printing processes have different capabilities in one direction relative to the other. As used herein, the metrics DPI or dpcm are intended to refer to either or both horizontal or vertical dimensions, with horizontal referring to the relatively longer dimension of a card, and vertical referring to the relatively shorter dimension of a card.

Other embodiments may include features <NUM> with a size large enough to be visually perceptible to the human eye to form an intended pattern, which may include geometric arrangements of dots, or visual patterns formed using pointillist artistic techniques that create an image. Features <NUM> may be provided in combinations of different types of metal, or metal and non-metal, with the different types of features having different color tones for graphical/artistic purposes. For example, dots may range from a metal with a silver tone (e.g. Aluminum) to a metal with a black tone (e.g. black ruthenium or black nickel) to create a <NUM>-tone graphic.

The use of more than two different color tones may be used to create visual images with the different tones, including with tones to create or approximate <NUM>-color printed images. For example, a color palate of metallic substances, such as ZrN (red), TiAlN (blue), TiN (gold), and TiAlCN (black) may be used to approximate the corresponding separations of a CMYK image. In combinations of metal and non-metal, the non-metal may comprise, for example, an ink with the same tone as the metal, so that visual effects incorporating darker tones may be formed by non-metal features in order to permit the metal features to remain at a predetermined spacing. In other embodiments, non-metal inks may be used in combination with a metal halftone pattern to fill in for one or more colors in a <NUM>-color separation. For example, a <NUM>-color image may be formed of a combination of features in yellow and black formed from a conductive (or relatively more conductive) metal (e.g. gold for yellow and black nickel for black) and magenta and cyan formed from non-conductive (or relatively less conductive) ink. In other embodiments, however, darker tones and lighter tones may be formed solely by metal features, with some areas in relatively darker tones comprising metal halftone dots that are not entirely separated from one another within the dark tonal area, and relatively lighter tonal areas in which the plurality of metal halftone dots are all separated from one another.

Relatively lighter and darker areas may be formed by FM or AM dot frequency modulation, wherein FM modulation entails using the same size dot throughout a visual pattern, wherein changes in spacing of the dots to form changes in tone, and AM modulation entails using different size dots at a same relative spacing on center to form changes in tone. Combinations of AM and FM modulation, such as are known in the field of halftone printing, may also be used, such as in which AM modulation is used for one part of the tonal range and FM modulation used for another.

Although discussed primarily herein with respect to use of a plurality of electrically insulated features on a glass layer, it should be understood that the methods as described herein may be performed on any type of substrate, including non-glass transparent (or translucent) polymer substrates, such as but not limited to polyethylene terephthalate (PET), including but not limited to high-density polyester (HDPE), low density polyester (LDPE), and glycol-modified polyester (PETG)), polycarbonate, acrylic (polymethlamethacrylate), butyrate (cellulose acetate butyrate), glass-reinforced epoxy laminate material (e.g. FR4), polypropylene, and polyether ether ketone (PEEK), as well as non-transparent / non-translucent substrates, including ceramic. In some embodiments, it may be desirable to use a halftone pattern as described herein to hide underlying layers, such as layers with discontinuities, such as described in <CIT>, titled DI METAL TRANSACTION DEVICES AND PROCESSES FOR THE MANUFACTURE THEREOF, and in <CIT>, published under <CIT>, (status: pending), which claims priority to <CIT>, both titled DI CAPACITIVE EMBEDDED METAL CARD.

Embodiments may comprise a combination of a first transparent layer having a discontinuous metal stratum comprising isolated metal features and a second transparent layer comprising a discontinuous metal stratum comprising a metal layer with a plurality of discontinuities. Cards may also include one or more transparent layers with a discontinuous stratum comprising isolated metal features in one area of the stratum and continuous metal region with a plurality of discontinuities in another area. Some regions of a transparent layer may have an absence of metal to permit transparency to another layer of the card (including transparency in a first metal stratum on a first surface of the layer that permits visibility of a second metal stratum on a second surface of the layer). Multiple transparent layers, each with corresponding discontinuous strata covering less than all of one or more surfaces of each layer, may include areas of transparency that provide visibility to an underlying surface or layer in a combination of patterns that create to create a <NUM>-dimensional optical effect. Thus, for example, as depicted in <FIG>, card <NUM> may have a first transparent layer <NUM>, in which transaction module <NUM> is embedded. A second transparent layer <NUM> may have a first discontinuous metal stratum <NUM> disposed on a first surface thereof, and an absence of metal in area <NUM>, that permits visibility of second discontinuous metal stratum <NUM> on the opposite surface of layer <NUM>. Although not shown, a further transparent (non-metallized) area in stratum <NUM> may be present that permits visibility to an additional underlying layer (not shown). In embodiments having transparent portions, the transparent portions may be rendered sufficiently non-transmissive (i.e. to meet the ISO/IEC <NUM> standard) for blocking the infrared (IR) wavelengths used by card-sensing devices (e.g. automatic teller machines (ATMs), which typically use LEDs with <NUM> or <NUM> wavelengths). IR blocking capabilities may be conferred by additives in the transparent materials that form the substrate (or another layer), a coating, or a layer having IR-filtering properties.

Claim 1:
A transaction card, comprising:
a first layer (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>);
and a discontinuous metal stratum (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>), characterised in that the discontinuous metal stratum is disposed on a first surface (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) of the first layer (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and comprises a plurality of isolated metal features (<NUM>, <NUM>, <NUM>) that form a halftone pattern; and in that the transaction card further comprises
a contact, contactless, or dual interface transaction module (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) disposed in the first layer (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and electrically isolated from the discontinuous metal stratum (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>).