A method for preparing a product comprising a substrate with at least one patterned layer

Abstract

A patterned multilayer film is prepared from a first film comprising a support layer and a second film comprising a conductive layer. The preparation process includes a first printing step in which the support layer of the first film is pre-printed in relief according to the desired patterns, followed by a second lamination step in which the first film with the pre-printed support layer is laminated to the second film containing the conductive layer to form the multilayer film, followed by a third step in which the conductive layer of the pre-printed / laminated multilayer film is subjected to a milling step to selectively remove predetermined portions of this conductive layer to form the patterned multilayer film, said predetermined portions having a structure corresponding to the pre-printed relief patterns. Figure 1

Description

Title of the invention: Method for preparing a product comprising a substrate with at least one patterned layer

[0001] The present invention relates to a method and device for preparing a product comprising a substrate with at least one patterned layer.

[0002] A known method for manufacturing conductors and electrical components on substrates consists of applying a layer of conductive material, illustratively a metal and / or a metal alloy and / or a doped resin, onto a substrate and then removing the undesirable parts of said layer by etching with chemical substances.

[0003] This process has many disadvantages, including the number of steps and the time required for its completion, as well as the use and management of the chemical substances used in the process.

[0004] EP1665912 and WO2022223539 describe similar methods that allow to eliminate the need for chemical substances. In these processes, a printing plate presses the desired pattern onto a conductive top layer placed above a dielectric base, and a milling cylinder mechanically removes the raised pattern from the top layer, leaving the base intact. This mechanical removal of material from the conductive top layer, performed simultaneously with the pressing of the desired pattern onto the material, thus allows the desired conductive pattern to remain on the material.

[0005] Although these processes are advertised as particularly effective for creating conductive patterns on materials with a conductive layer, the simultaneous management of patterned cliché cylinder and milling equipment generates complexity in the implementation of the process while making certain achievements difficult or even impossible.

[0006] Thus, improving a device and a method that facilitates the manufacturing of a structure / pattern on a multilayer material, in a simple, fast and reliable way, remains an important challenge which the present invention advantageously addresses as explained in the remainder of the description of the present invention. Description of the invention

[0007] The invention is defined by the independent claims.

[0008] Embodiments are presented in the dependent claims and in the description and figures.

[0009] According to a first aspect, the invention relates to a method for preparing a patterned multilayer film from a first film comprising a support layer and a second film comprising a conductive layer, the process comprising a first printing step in which the support layer of the first film is pre-printed in relief according to the desired patterns, followed by a second lamination step in which the first film with pre-printed support layer is laminated by the second film comprising the conductive layer to form the multilayer film, followed by a third step in which the conductive layer of the pre-printed / laminated multilayer film is subjected to a milling step to selectively remove predetermined parts of this conductive layer to form the patterned multilayer film, said predetermined parts having a structure corresponding to the pre-printed relief patterns.

[0010] It is therefore the pre-printed relief which conditions the parts of the conductive layer which are removed during the milling step.

[0011] In one execution mode, the thicknesses of the predetermined parts are variable.

[0012] This process makes it possible to do away with the patterned cliché cylinders of the prior art in which the patterned cliché cylinders are in the form of a cylindrical support having a patterned envelope surface; with the patterns comprising raised parts which correspond to the parts of material which must be removed and hollow parts which correspond to the parts of material which must be retained.

[0013] Although the present process requires three distinct steps, its implementation has proven simple, quick, and reliable, while also offering numerous other advantages, including improved precision of the patterns to be produced and enhanced mechanical strength of the patterned multilayer film. The process also allows for milling (and therefore pattern creation) near the ends of the multilayer film.

[0014] According to an advantageous aspect, the process can be carried out continuously in the corresponding device.

[0015] The first film (also called the support film) comprises a support layer. It is advantageously flexible and can be in the form of a reel or roll of continuous tape; alternatively, it can be in the form of sheets, in which case a flexible or rigid film is possible. Thus, the first film can advantageously be supplied from a tape reel or roll or from a magazine containing a plurality of stacked sheets.

[0016] The second film (also called the conductive film) comprises a conductive layer. It is advantageously flexible and can be in the form of a continuous tape reel or roll or in the form of sheets. Thus, the second film can advantageously be supplied from a tape reel or unwinding reel or from a magazine containing a plurality of stacked sheets.

[0017] The support layer of the first film is advantageously made of a dielectric material.

[0018] The conductive layer of the second film is the layer of the multilayer film which must be provided with a pattern or structure.

[0019] Milling

[0020] The term "milling" refers to any suitable milling technique adapted to selectively remove predetermined portions of at least one conductive layer from a multilayer film; these predetermined portions of the conductive layer of said film thus represent the patterns and may also be of varying thicknesses, insofar as it is desired to remove part of the thickness of the conductive layer, all of it, and / or all of it and part of the thickness of the underlying layer (substrate). The milling process uses a milling cutter that encompasses all rotating bodies having an abrasive surface or a milling envelope equipped with teeth, grains, or abrasive particles, for example, sand, diamond particles, or other similar materials.

[0021] The milling cutter can advantageously be in the form of a milling cylinder, for example in the form of a cylindrical milling wheel, with cutting teeth extending along an axial direction of a cylinder envelope surface, for example helically or straight along the axial direction.

[0022] The patterns or structures made in the conductive layer of the multilayer film can vary both in the direction of advancement of the film in the device and in the transverse direction of said device.

[0023] Selective removal of predetermined parts of the conductive layer can be carried out in a single milling step or partially during several consecutive milling steps.

[0024] After the single milling step or the final milling step, at least part of the thickness of the conductive layer, the entire conductive layer, or the entire conductive layer and part of the thickness of the support layer, was cut out by selectively removing predetermined parts, revealing the desired patterns.

[0025] Since the multilayer film can advantageously include layers other than the support layer and the conductive layer, the milling can also include the removal of material from other layers, such as one or more cover layers overlying the conductive layer or one or more underlying layers of the conductive layer.

[0026] In one embodiment, a single milling cutter will suffice to perform the single step or the plurality of milling steps.

[0027] As an alternative, a plurality of identical or different strawberries may be provided.

[0028] Support layer

[0029] The support layer of the first film is therefore advantageously made of a dielectric material. This first film and / or its support layer may themselves be multilayered; they may thus include one or more dielectric films. This first film and / or its support layer, or, more generally, the dielectric material, may be made of paper or a plastic material, for example, paper, polyethylene terephthalate, polycarbonate, polyimide, and / or polyethylene polynaphthalate.

[0030] This support film may advantageously have a thickness greater than or equal to 20 microns, for example greater than or equal to 35 microns.

[0031] This support film may advantageously have a thickness less than or equal to 200 microns, for example less than or equal to 100 microns.

[0032] In the illustration whereby the entire conductive layer and a portion of the support layer have been cut out by selectively removing predetermined sections to reveal the desired patterns, it is obvious to those skilled in the art that the thickness of the support layer will have been reduced in the areas of said patterns. In order to guarantee the integrity of the film and, by way of illustration, at least 75% of the thickness of the support layer, for example, at least 90% of said thickness is retained.

[0033] Conductive layer

[0034] The conductive layer of the second film may advantageously be made of one or more metals, a metallic alloy, and / or a conductive polymer. This second film and / or its conductive layer may themselves be multilayered. This second film and / or its conductive layer may be made of aluminum, copper, copper-clad aluminum, tin, gold, silver, nickel, carbon, and / or a corresponding alloy, for example, a copper alloy or a copper-nickel alloy.

[0035] This conductive film may advantageously have, before the milling step, a thickness greater than or equal to 5 microns, for example greater than or equal to 40 microns.

[0036] This conductive film may advantageously have, before the milling step, a thickness less than or equal to 150 microns, for example less than or equal to 100 microns.

[0037] The multilayer film may also include one or more additional layers to the support and conductive layers.

[0038] By way of illustration, the conductive layer can be covered with a protective layer.

[0039] This protective layer can advantageously be formed of a dielectric material which will advantageously be selected from the dielectric materials already described for the support layer; this material may be identical or different from that of the support layer. The presence of a protective layer or any other layer placed above the conductive layer to be milled will necessitate that it also be milled when creating the patterns.

[0040] The multilayer film may also include one or more additional conductive layers, the material of which will advantageously be selected from the conductive materials already described above for the conductive layer to be milled; this material may be identical or different from that of the conductive layer to be milled.

[0041] The additional conductive layer(s) may have substantially the same thickness as the conductive layer to be milled, or a different thickness (lower or higher).

[0042] This additional conductive layer or layers can advantageously be arranged as an intermediate conductive layer sandwiched between the support layer and an additional intermediate dielectric layer. In this arrangement, the conductive layer to be milled is positioned above this intermediate dielectric layer.

[0043] Alternatively, the support layer can be disposed between the conductive layer to be milled and the additional conductive layer.

[0044] The embossing step therefore consists of pre-printing the substrate layer of the first substrate film with the desired embossed pattern. Any suitable printing method may be used, provided that it allows the embossed pattern to be created on the side of the substrate film on which the lamination with the conductive film will be carried out.

[0045] Optionally, the embossing step is followed by a drying step at the end of which the thickness of the printed and dried printing product is equal to or greater than 4 microns, equal to or greater than 5 microns, equal to or greater than 15 microns, or equal to or greater than 40 microns.

[0046] Optionally, the embossing step is followed by a drying step at the end of which the thickness of the printed and dried printing product is equal to or greater than the thickness of the conductive layer to be milled.

[0047] Optionally, the embossing step is followed by a drying step at the end of which the thickness of the printed and dried printing product is less than 250 microns, or less than or equal to 100 microns.

[0048] Optionally, in which the thicknesses of the predetermined parts are variable.

[0049] Optionally, the printed product is digitally printed by inkjet printing.

[0050] PRINTING PRODUCT

[0051] In one embodiment, the printed product may consist of 3D varnish; it may also consist of hot melt inks / glues (hardening at room temperature).

[0052] In one embodiment, the printing product comprises a thermoplastic material, for example a thermoplastic polymer, and optionally, a thermosetting material. This printing product, pre-printed on the support layer of the backing film, guarantees the design of the future milled pattern and thus of the prepared multilayer patterned film.

[0053] By way of illustration and not limitation, this printing product may be composed of toner and / or ink and / or varnish; it is preferably dielectric.

[0054] By way of illustration and not limitation, in the case of a varnish, it may be solvent-based, aqueous, or UV-based. When it is UV-based, it may be cross-linked using LEDs and / or UV radiation.

[0055] According to a particular embodiment, the printing product is of the UV ink and / or UV varnish type, comprising a thermosetting material as well as the thermoplastic material; the presence of at least one photoinitiator in the composition of the printing product is also preferred. It is the presence of this thermosetting material that characterizes the fact that the corresponding ink / varnish exhibits thermosetting behavior. According to a particular embodiment, the pre-printed printing product (and therefore the pre-printed pattern) is crosslinked before the milling step. This can be achieved by ensuring that the polymer network of the printing product is at its optimum in terms of three-dimensional density through the reaction of all the photoinitiator sites.This can also result in thermosetting behavior, meaning that the thermosetting part of the varnish no longer has a glass transition temperature Tg but only a destruction temperature; thus, this thermosetting polymer present in the varnish will never become soft and will not develop a sticky surface because it will be completely dry to the touch.

[0056] Thus, according to certain embodiments, the claimed process comprises, after the printing step of the printed product and before milling, an activation step (for example, using UV rays) for cross-linking the printed product (the ink and / or varnish). This activation step will advantageously take place before or during the lamination step, preferably before lamination.

[0057] The addition of a thermoplastic material to the printing product made it possible to improve the selective adhesion between the printed pattern and the support film.

[0058] In a particular embodiment, the printing product, preferably of the ink / varnish type, comprises at least 5% by weight of thermoplastic material, per For example, at least 10% by weight, preferably at least 15% by weight. Even if high concentrations of thermoplastic material are conceivable, the printing product, preferably of the ink / varnish type, will preferably comprise less than 40% by weight, for example less than 30% by weight, preferably less than 25% by weight of thermoplastic material.

[0059] Thus, in a particular embodiment, the printing product, preferably of the ink / varnish type, comprises at least 60% by weight, for example at least 70% by weight, preferably at least 75% by weight of material intended to be thermosetting.

[0060] Thus, in an embodiment particularly applicable to varnishes / inks, the thermoplastic material is characterized by a Tg value less than 60°C, for example less than 50°C, preferably less than 40°C.

[0061] Since the ink / varnish type printing product includes only limited quantities of thermoplastic material, it is evident that the Tg of the printing product will, after deposition (and crosslinking), have a value that will be different from the Tg of the thermoplastic material included in said product.

[0062] When the printing product is a toner, its thermoplastic material content is generally greater than 30% by weight, greater than 40% by weight, or even greater than 50% by weight.

[0063] In a particular embodiment, the printing product is an ink or a varnish. After deposition / curing, this printing product is in the form of a film which is advantageously characterized by a Tg value between -20°C and 200°C, for example between 0°C and 200°C, for example between 10 and 50°C, for example between 15°C and 40°C.

[0064] In a particular embodiment, the printing product is a toner. After deposition, for example by xerography, this printed printing product is in the form of a film which is advantageously characterized by a Tg value between 0°C and 200°C, for example between 40°C and 120°C, for example between 40°C and 70°C.

[0065] The temperature (Tg) of the film of the printed / (cured) printing product (varnish / ink / toner) will be measured by any suitable method. By way of illustration, we will mention differential scanning calorimetry (DSC), which is a well-established thermal analysis method for measuring various temperatures and transition states.

[0066] By way of illustration, the polymer sample will be subjected to a temperature ramp of approximately 10°C / min, the heat flux of which is measured in Watts. The glass transition temperature marks the change from the glassy to the rubbery state of the material, which is an endothermic phenomenon. Therefore, to determine the value of Tg, it is sufficient to wait for the observation of a decrease in the heat flux. thermal resistance is determined as a function of temperature, followed by the use of a tangential method. The value obtained corresponds to the Tg of the polymer using the DSC method.

[0067] The sample used for the measurement may advantageously come from the material constituting the printing product after printing and crosslinking.

[0068] In one embodiment, any UV-based UV-based system usable in the field of non-contact printing, and more particularly in the field of digital non-contact printing using piezoelectric printheads, can advantageously be used. Inkjet deposition is well known to those skilled in the art and can be carried out according to a known inkjet deposition technique, preferably the drop-on-demand (DOD) technique, which consists of creating overpressure using a piezoelectric component that bends under the effect of an electrical voltage to reduce the volume of the ink reservoir and thus eject a drop of varnish.

[0069] While there are no real restrictions on the choice of UV varnish suitable for inkjet deposition for use within the scope of the present invention, it is nevertheless advantageous to select certain characteristics in order to use varnishes that maximize the final result. It is therefore clear that preference will be given to the use of UV varnishes compatible with inkjet nozzles.

[0070] This implies that the choice of non-contact UV printing varnish, preferably a UV varnish for inkjet nozzles (preferably for piezoelectric printheads), will preferably be made according to one or more of the criteria indicated below: - a varnish viscosity of less than 500 mPa.s at 25°C, preferably less than 200 mPa.s at 25°C, preferably less than 100 mPa.s at 25°C, for example less than 50 mPa.s at 25°C; and / or - the absence in the varnish of components with a particle size greater than or equal to 50 µm, preferably the absence of components with a particle size greater than or equal to 10 µm, and even more preferably the absence of components with a particle size greater than or equal to 1 µm. Indeed, the varnishes used are preferably systematically filtered to guarantee the safety and reliable operation of the print heads; and / or - a surface tension of the varnish between 10 mN / m and 50 mN / m at 25°C, preferably between 18 and 25 mN / m at 25°C in order to ensure efficient spreading on a wide range of substrates.

[0071] Thus, in certain embodiments, the varnish (for coating the surface of a substrate and deposited by inkjet printing) will have a composition that preferably meets one or more of the criteria indicated below: - the presence of at least one monofunctional or difunctional acrylate curable monomer, or a mixture of two or more monofunctional and / or difunctional acrylate curable monomers, preferably in a content greater than 50% by weight, for example in a content between 60 and 85% by weight of the varnish; and / or - the absence in the varnish of urethane-based compounds, and / or - the absence in the varnish of curable acrylate monomer of only acrylate functionality, and whose functionality is greater than 3; and / or - the presence of a photoinitiator, preferably in a content of between 2 and 10% by weight of the varnish; and / or - the presence of a surfactant, preferably in a concentration of between 0.1 and 3% by weight of the varnish; and / or - the presence of passive (non-reactive) resins, preferably in a content of between 5 and 20% by weight of the varnish; and / or - the presence of modified acrylate amine, preferably in a content of between 2 and 10% by weight of the varnish; and / or - the varnish composition preferably being solvent-free • preferably free from water and organic solvents such as, for example, methyl isobutyl ketone, methyl ethyl ketone, dimethyl ketone, isopropyl alcohol, isobutyl alcohol, n-butyl alcohol, ethyl acetate, n-butyl acetate, ethyl cellosolve, butyl cellosolve and other similar solvents.

[0072] According to one embodiment, the sum of the varnish components mentioned above will preferably represent at least 70% by weight of the varnish, preferably at least 85% by weight, for example at least 95% by weight, or even the entire varnish.

[0073] According to a preferred, but not limiting, method of operation, the determination of the physical parameters of the components or composition of the UV varnish is carried out at the indicated temperatures and under typical Earth surface pressure conditions, preferably on the order of one atmosphere (1013 m bar). Viscosity can thus be measured using a HAAKE Viscotester 550 viscometer equipped with a Cup NV and a Rotor NV, which are known measuring instruments marketed by Thermo Fisher, incorporating a temperature control system connected to a thermostatically controlled bath that maintains the varnish sample at a temperature of 25 °C. Similarly, surface tension is measured using a DSA 100 tensiometer with the droplet method, marketed by KRUSS.Particle size and conductivity are respectively measured using a particle size measuring device called MASTERSIZER 2000, marketed by the. MALVERN company, and on the other hand a CYBERSCAN CON 1 1 conductivity meter from EUTECH INSTRUMENTS with a reference measuring cell ECCONSEN91 W / 35608-50 whose cell constant is K=1 .0.

[0074] Among the curable monofunctional acrylate monomers that can advantageously be used in varnishes, examples include monoacrylates and / or compounds derived from said monoacrylates, taken individually or in mixtures of two or more of said compounds. For illustrative purposes, aliphatic alkyl monoacrylates and / or their derivatives, in particular aliphatic alkyl monoacrylates having more than five carbon atoms, and / or their derivatives, are given. Also given for illustrative purposes are aromatic alkyl monoacrylates and / or their derivatives, in particular aromatic alkyl monoacrylates having more than five carbon atoms and / or their derivatives.Examples include, but are not limited to, 2-(2-ethoxyethoxy)ethyl acrylate "EOEOEA", phenol ethoxylated monoacrylate, Cyclic Trimethylopropane Formal Acrylate "CTFA", octyl-decyl-acrylate "ODA" (which also has the property of restricting surface tension in varnish), tridecyl acrylate "TDA", octyl acrylate, isodecyl acrylate "IDA", 3,3,5-trimethyl cyclohexyl acrylate, iso-octyl acrylate "IOA", isobomyl acrylate "IBA", 3,3,5-trimethyl cyclohexanol acrylate "TMCHA", tetrahydrofurfuryl acrylate "THFA", and / or a mixture of two or more of the aforementioned compounds.

[0075] Among the difunctional diacrylate curable monomers that can advantageously be used in varnishes, diacrylates and / or compounds derived from said diacrylates, taken individually or in mixtures of two or more of said compounds, may be cited by way of example. By way of illustration, aliphatic alkyl diacrylates and / or their derivatives, in particular aliphatic alkyl diacrylates having more than five carbon atoms, and / or their derivatives, may be cited. By way of illustration, aromatic alkyl diacrylates and / or their derivatives, in particular aromatic alkyl diacrylates having more than five carbon atoms, and / or their derivatives, may also be cited.Examples include, but are not limited to, triethylene glycol diacrylate (TIEGDA), tripropylene glycol diacrylate (TPGDA), dipropylene glycol diacrylate (DPGDA), polyethylene glycol diacrylate, polypropylene glycol diacrylate, propoxylated neopentylglycol diacrylate, hexanediol diacrylate (HDDA), esterdiol diacrylate (EDDA), 3-methyl 1,5-pentanediol diacrylate (MPDA), polybutadiene diacrylate (PBDDA), decanediol diacrylate (DDDA), tricyclodecanedimethanol diacrylate (TCDDMDA), tetraethylene glycol diacrylate (TTEGDA), and / or a mixture of two or more of the aforementioned compounds.

[0076] PRINTED PATTERN

[0077] Any suitable method may be used for relief printing. Examples include, but are not limited to, screen printing, inkjet printing, and xerography. etc... Depending on the specific method of execution, the printed product is digitally printed, for example, by inkjet printing or xerography, preferably by inkjet printing. This inkjet printing allows for the very precise embossing of areas or patterns, depending on the composition of the printed product. Toner xerography is another option well known to those skilled in the art.

[0078] This printing step will therefore advantageously be digital, for example by inkjet printing of varnish / ink or by electrophotographic printing (xerography) of toner.

[0079] An advantageous feature of the claimed process and device is that the digitally printed relief pattern consists of a printing product (varnish / ink / toner) which is compatible in terms of surface tension with the support layer of the support film (in particular with its porosity), which results in a high resolution of the printed pattern which will generate high precision of the pattern when milling the second film, in particular the conductive layer of the second film of the multilayer film.

[0080] When the printing product is an ink or varnish, inkjet printing techniques in relief of the printing pattern will be preferred, for example using piezoelectric print heads, adapted according to the printing product.

[0081] The areas (and therefore the patterns) can advantageously be any kind of desired geometric shape; they can theoretically be made of different materials, for example inks and / or varnishes and / or toner, although it is preferable to use only one type of dielectric printing product when embossing.

[0082] In one embodiment, thanks to the illustrated printing techniques, the thickness of the printed printing product can advantageously be variable; this makes it possible to obtain a patterned film whose conductive characteristics are precisely controlled.

[0083] By way of illustration and not limitation, we will cite a thickness of the film of printing product (ink / varnish / toner) deposited / dried and measured before milling equal to or greater than the thickness of conductive layer to be milled.

[0084] By way of illustration, the thickness of the printing product film is equal to or greater than 4 microns, for example equal to or greater than 5 microns, for example equal to or greater than 15 microns, for example equal to or greater than 40 microns; and / or a thickness of the printing product film (ink / varnish / toner) deposited / dried and measured before milling less than 250 microns, for example less than or equal to 100 microns.

[0085] According to a second aspect, the invention relates to a device for preparing a patterned multilayer film from a laminated multilayer film comprising a support layer from a first film and at least one conductive layer from a second film, the device comprising at least one embossing station in which the support layer of the first film is pre-printed in relief according to the desired patterns and a lamination station in which the first pre-printed film and a second film with a conductive layer are laminated and a milling station configured to selectively remove predetermined parts of this conductive layer from the obtained pre-printed / laminated multilayer film, said predetermined parts having a structure corresponding to the embossed preprints.

[0086] The device is therefore configured so that, during its use, the embossed preprint of the support film of the multilayer film generates a corresponding relief on the opposite part of the film as it passes through the milling station, a corresponding relief which can be selectively milled in order to produce the patterned multilayer film.

[0087] The method and device described in the aspects of the present invention can be used to produce the patterned multilayer film.

[0088] Thus, according to a third aspect, the invention relates to a patterned multilayer film prepared by the claimed process.

[0089] Thus, according to a fourth aspect, the invention relates to a patterned multilayer film prepared using the claimed device.

[0090] The patterned multilayer film can advantageously be used as an electronic component and therefore advantageously used in fields where electronic components are useful, for example for heating elements, radiators, LED lighting, cable harnesses, flexible printed circuits, etc. Figures

[0091] [Fig. 1] Fig. 1 represents an example of an embodiment of the device and method of preparation of a patterned multilayer film related to the invention.

[0092] [Fig.2] Fig.2 represents an example of an embodiment of the milling device / cleaning 7 and the corresponding process related to the invention.

[0093] [Fig.3] Fig.3 represents two examples of film production (FILM I and FILM I) II) in connection with the invention.

[0094] By way of illustration, [Fig. 1] describes the roll-to-roll type device for the multilayer film in strip form and is read from right to left. It describes a backing film unwinder 1, a preferred optional strip guide device 2, a preferred optional registration device 3, and a printing device 4 (preferably a system inkjet), a drying device 5, a preferred optional control device 6, a conductor film unwinder 12, an illumination device 13, a milling / cleaning device 7, a preferred optional web guiding device 8, a preferred optional control device 9, a patterned multilayer film rewinder 10, and control means 11 for the device. These control means are preferably computer-based; these computer-based means advantageously control the various workstations and also collect information from the various sensors installed along the device in order to synchronize the successive steps.

[0095] The registration device 3 may advantageously include camera(s), sensor(s) and / or scanner(s) enabling the synchronization of operations and in particular the positioning of the embossed print using a computer file representing said pattern according to registration marks located on the film.

[0096] The 4-point inkjet printing system may include a print bar or a set of print heads operating in scanning mode. In scanning mode, the machine may include magazines (consisting of rollers that can move apart and together) for storing a portion of the web (called "buffers") to allow continuous operation of the milling system. Preferably, the ink / vemis used is colored to facilitate optical verification of print quality with the control device 6.

[0097] The control device 9 allows the quality of the treated film production to be verified. It advantageously includes an optical control and / or a thickness control device.

[0098] The aforementioned computer means do not need to be detailed in this application and may, for example, be integrated into the device or housed in a separate device. The sensors provide, for example, information on film position, film configuration information, and information on areas to be printed and / or milled, and / or validation information following a correctly performed or incorrect operation. Certain information necessary for implementing the invention may also be pre-recorded in the computer means (for example, via input on an interface by an operator). Such information may, for example, concern the shape and / or dimensions of the films (e.g., their thickness), the location of the patterns to be printed and / or milled, the thickness of the ink and / or varnish layer, the drying power, etc.However, it is generally preferred that sensors measure or verify such information.

[0099] In the illustration according to [Fig. 1], the films are therefore unwound / rewound in reel-to-reel type devices. Alternatively, the support films awaiting printing and, optionally, the conductive films, can be in substrate form of the sheet type and generally, in a manner known per se, placed in at least one input area, for example an input magazine with a storage capacity defined according to the nature of the substrate and the requirements for printing and / or lamination. In one embodiment, an input magazine is designed to accept several dozen, hundreds, or even thousands of substrates of varying nature, thickness, and dimensions (for example, and without limitation, from a format with sides on the order of a centimeter, for example, an A10 format, or more precisely, a credit card format; up to a format with sides on the order of several meters, for example, an AO format or a 2 x 2 meter format).Once the printing / laminating / milling processes are complete, the processed substrates are directed to an output area, for example, stored in at least one output magazine, which generally has the same storage capacity as the input magazine. A suitable substrate transport system through the printing / laminating / milling stations is also included in this illustration.

[0100] By way of illustration, [Fig. 2] describes an example of an embodiment of the milling / cleaning device 7 and the corresponding method related to the invention. This device 7 advantageously comprises an input tension adjustment device 71 for the film to be milled, an output tension adjustment device 72 for the milled / cleaned film, a milling device 73, an optional and preferred cleaning device 74, an optional and preferred suction device 76, and a counter-pressure roller 75.

[0101] The milling / cleaning device 7 may advantageously include one or more milling rollers adjustable in speed and distance from the counter-pressure roller(s) 75. Several milling rollers allow for progressive milling which limits the risk of tear-out.

[0102] The milling / cleaning device 7 may advantageously include one or more cleaning systems composed, for example, of suction brushes, or of electrostatic systems.

[0103] The inlet tension adjustment device 71 of the milling film and the outlet tension adjustment device 72 of the milled / cleaned film are advantageously motorized. They participate in the movement of the film and allow its tension to be adjusted.

[0104] Fig. 3 represents two examples of film production.

[0105] It can be seen in the left part of the figure - at the top, the support film with its support layer having been printed in three places by the printing of the raised varnish / ink patterns; said relief being of identical thickness in this realization; - in the lower part the printed / laminated film with its printed backing film and its conductive film

[0106] It can be seen in the right-hand part of the figure - in the upper part, the printed / laminated / milled film after superficial milling; - in the lower part, the same film printed / laminated / milled after a deeper milling.

[0107] This application describes various technical features and advantages with reference to the Figures and / or various embodiments. Those skilled in the art will understand that the technical features of a given embodiment can in fact be combined with features of another embodiment unless the contrary is explicitly stated, or it is obvious that such features are incompatible, or that the combination does not provide a solution to at least one of the technical problems mentioned in this application. Furthermore, the technical features described in a given embodiment can be isolated from the other features of that embodiment unless the contrary is explicitly stated.

[0108] It should be obvious to those skilled in the art that the present invention permits embodiments in many other specific forms without departing from the scope of the invention as claimed. Therefore, the present embodiments should be considered illustrative, but may be modified within the scope defined by the attached claims, and the invention should not be limited to the details given above.

Claims

Demands

1. A method for preparing a patterned multilayer film from a first film comprising a support layer and a second film comprising a conductive layer, the method comprising a first printing step in which the support layer of the first film is pre-printed in relief according to the desired patterns, followed by a second lamination step in which the first film with pre-printed support layer is laminated by the second film comprising the conductive layer to form the multilayer film, followed by a third step in which the conductive layer of the pre-printed / laminated multilayer film is subjected to a milling step to selectively remove predetermined portions of this conductive layer to form the patterned multilayer film, said predetermined portions having a structure corresponding to the embossed pre-prints.

2. A method for preparing a multilayer film according to claim 1 in which the support layer is made of a dielectric material.

3. A method for preparing a multilayer film according to claim 2 in which the dielectric material is formed of paper or a plastic material, for example paper, polyethylene terephthalate, polycarbonate, polyimide and / or polyethylene polynaphthalate.

4. A method for preparing a multilayer film according to any one of the preceding claims wherein the support layer film has a thickness greater than or equal to 20 microns, or greater than or equal to 35 microns.

5. A method for preparing a multilayer film according to any one of the preceding claims wherein the support layer film has a thickness less than or equal to 200 microns, or even less than or equal to 100 microns.

6. A method for preparing a multilayer film according to any one of the preceding claims, wherein the conductive layer is formed of one or more metals, a metallic alloy and / or a conductive polymer.

7. A method for preparing a multilayer film according to claim 6, wherein the conductive layer is made of aluminum, of copper, copper-clad aluminum, tin, gold, silver, nickel, carbon, a corresponding alloy, a copper alloy, and / or a copper-nickel alloy.

8. A method for preparing a multilayer film according to any one of the preceding claims wherein, before the milling step, the conductive layer has a thickness greater than or equal to 5 microns, or greater than or equal to 40 microns.

9. A method for preparing a multilayer film according to any one of the preceding claims wherein, before the milling step, the conductive layer has a thickness less than or equal to 150 microns, or less than or equal to 100 microns.

10. A method for preparing a multilayer film according to any one of the preceding claims wherein the milling step is carried out by means of a milling cutter (7) in the form of a milling cylinder, for example in the form of a cylindrical milling wheel, with cutting teeth extending along an axial direction of an envelope surface of the cylinder, for example helically or straight along the axial direction.

11. A method for preparing a multilayer film according to any one of the preceding claims, wherein the embossing step is carried out using a printing product that is a 3D varnish.

12. A method for preparing a multilayer film according to any one of the preceding claims, wherein the embossing step is followed by a drying step at the end of which the thickness of the printed and dried print product is equal to or greater than 4 microns, equal to or greater than 5 microns, equal to or greater than 15 microns, or equal to or greater than 40 microns.

13. A method for preparing a multilayer film according to any one of the preceding claims, wherein the embossing step is followed by a drying step at the end of which the thickness of the printed and dried printing product is equal to or greater than the thickness of the conductive layer to be milled.

14. A method for preparing a multilayer film according to any one of the preceding claims, wherein the embossing step is followed by a drying step at the end of which the thickness of the printed and dried printed product is less than 250 microns, or less than or equal to 100 microns.

15. A method for preparing a multilayer film according to any one of the preceding claims wherein the thicknesses of the predetermined parts are variable.

16. A method for preparing a multilayer film according to any one of the preceding claims, wherein the printed product is digitally printed by inkjet printing.

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