METHOD FOR PRODUCING A MULTI-LAYER BODY AND A MULTI-LAYER BODY

Description

[0001] The invention relates to a method for producing a multilayer body and to a multilayer body.

[0002] It is known to provide sensors, in particular touch sensors, in plastic films. Such a sensor film is described, for example, in DE 10 2011 111 506 A1. This sensor film has a carrier film to which transparent conductor tracks are applied. By appropriately arranging or superimposing these conductor tracks, capacitive touch sensors are formed in the sensor film. Documents US 2016 / 0192474 A1, US 2003 / 0121767 A1, DE 203 08 525 U1, DE 203 07 486 U1, US2006104037A1, and US 6,824,321 B1 each describe a multilayer body and a method for producing the multilayer body using a thermoforming process. The document JP 6 140 769 B2 describes a multilayer body whose surface relief is caused by a deformation mechanism based on tension / compression mechanisms, piezoelectric materials, or microelectronic-mechanical system elements.

[0003] When using such sensors, it may be necessary or desirable to combine the electrical functionality with additional optical or decorative elements.

[0004] It is an object of the present invention to provide an improved method for producing a multilayer body and an improved multilayer body which provides a sensor functionality.

[0005] The object is achieved by a method for producing a multi-layer body according to claim 1.

[0006] Furthermore, the object is achieved by a multi-layer body according to claim 11.

[0007] Such a method for producing a multilayer body and such a multilayer body are characterized by the fact that, through the selection of the process parameters and the materials used for the components of the multilayer body, such as the components of the sensor films and / or the substrate, a surface relief is created on the first surface of the substrate facing away from the sensor film. The sensor film and the sensor area of ​​the sensor film are thus protected from environmental influences by the substrate. Since the substrate is manufactured separately before being combined with the sensor film, dimensionally stable and chemically resistant materials can be used for the substrate, which are not compatible with the processes used in the production of the sensor film for producing the delicate conductor tracks for providing the sensor functionality.Furthermore, during the production of the substrate, additional decorative designs can be incorporated into and / or applied to the substrate, which also do not have to be compatible with the "sensitive" process conditions during the production of the sensor foils. Furthermore, the method according to the invention ensures that a surface relief is formed on the surface of the substrate facing away from the sensor foil, which, when used as a user interface, provides appropriate protection or, if appropriate, a corresponding decorative design for the sensor functionality. The corresponding surface design can be "controlled" by the sensor foil. It is not necessary to use additional registration processes or the like and to create separate embossing dies for forming the surface relief.Rather, a register-accurate arrangement of the surface relief to the sensor functionality can be created in a simple manner without additional process engineering effort.

[0008] Advantageous embodiments of the invention are described in the subclaims.

[0009] In particular, it is possible that at least one sensor film of the one or more sensor films is preferably designed and / or provided as a transfer film, as a laminating film, as an in-mold film, as a label, as an in-mold label and / or as a sensor label.

[0010] Preferably, when providing at least one of the one or more sensor films, the shape, in particular the contour and / or the relief, of the at least one sensor film is modified. Furthermore, the shape, in particular the contour and / or the relief, of the at least one sensor film is modified by molding at least one surface relief, wherein the at least one surface relief is molded into one or more layers of the sensor film, in particular by means of methods selected from thermal replication, UV replication, laser ablation, embossing, punching, cutting, and injection molding.

[0011] Further preferably, the shape, in particular the height relief and / or the contour, of the at least one sensor film is modified by applying one or more elements to a base film of the sensor film, which are preferably applied by means of one or more of the following methods: printing, in particular printing a lacquer and / or by means of 3D printing, casting, laminating or gluing a single-layer or multi-layer film element, in particular a plastic label, applying a fabric, in particular glass fiber fabric, applying a fiber material, in particular an organic fiber material, back-injection molding, applying the one or more elements by means of a transfer method, in particular a hot or cold embossing method.

[0012] It is further possible that one or more plastic labels and / or one or more functional elements are applied as one or more elements, in particular to a first surface of a base film of the sensor film, wherein the first surface of the base film preferably faces the first surface of the sensor film and / or the first surface of the base film preferably partially forms the first surface of the sensor film.

[0013] It is also possible for one or more plastic labels and / or one or more functional elements to be applied, in particular, to one or more of the one or more plastic labels and / or functional elements applied to the first surface of the base film of the sensor film. Further preferably, the one or more plastic labels and / or functional elements are applied to the base film in the sensor region of the sensor film and completely or partially overlap the sensor region, in particular projected onto the plane spanned by the first surface of the at least one sensor film.

[0014] It is also possible for the sensor film to have, in particular, at least one connection region and / or at least one contact region for contacting, in particular for electrical contacting, one or more sensor elements arranged in the sensor region, and for the one or more plastic labels and / or functional elements to be applied to the base film in the sensor region of the sensor film and to preferably completely or partially overlap the sensor region, in particular projected onto the plane spanned by the first surface of the at least one sensor film, but preferably not to overlap the connection region and / or the contact region of the sensor film.

[0015] It is further possible that the at least one connection area has one or more contact areas, in particular for electrical contacting.

[0016] Preferably, one or more sensor films of the one or more sensor films consist of only one or more sensors. However, to form the surface relief in the first surface of the substrate, it has proven advantageous for one or more sensor films of the one or more sensor films to be constructed from multiple layers. Such layers preferably comprise one or more plastic labels and / or one or more functional elements in any desired sequence starting from the first surfaces of the respective sensor films, wherein one or more functional elements of the one or more functional elements are designed as 3D elements or as functional elements extending in all spatial directions.

[0017] Furthermore, it is possible for one or more sensor films of the one or more sensor films to comprise one or more additional, preferably printed, haptic elements. Haptic elements in particular have tactilely detectable structures or other properties. One or more haptic elements of the one or more haptic elements are designed as functional elements extending in all spatial directions and / or are haptically detectable, in particular by human fingertips and / or thumbtips.

[0018] It is possible to accommodate the at least one connection region and / or contact region of the sensor film by means of tool adaptations. In particular, the at least one connection region and / or contact region is at least partially not back-injected and protrudes in particular like a flag from the rest of the multilayer body and / or the single-layer or multi-layer substrate, wherein the connection region and / or contact region protrudes in particular such that it can be guided to a mating contact to which the at least one connection region and / or contact region can be connected. Preferably, a non-back-injected connection region and / or contact region in the form of a flag is not provided at the edge of the multilayer body and / or the single-layer or multi-layer substrate.Preferably, the connection region and / or contact region, in particular the flag-like connection region and / or contact region, protrudes from one or more surfaces and / or surface regions of the multilayer body and / or the single-layer or multilayer substrate. Further preferably, the multilayer body and / or the single-layer or multilayer substrate is attached to or inserted into other elements of an electrical device at one or more edge regions, wherein, in particular, the possibility of contacting the at least one connection region and / or contact region, in particular the at least one electrical connection region and / or contact region, preferably remains intact.

[0019] Furthermore, it is possible that contact pins are used as a contacting method, so that at least one sensor without a connection area and / or contact area is subsequently contacted by means of contact pins.

[0020] Furthermore, it is possible to design the length of the contact area in such a way that the contact area is led out laterally and, in particular, is naturally imprinted, wherein such an imprint is preferably taken into account in the design.

[0021] During lamination, it is possible to vary the laminating temperature and / or laminating pressure during the lamination process. For example, lamination can begin with a low laminating temperature and then increase it gradually or unevenly, and / or begin with a low laminating pressure and then increase it gradually or unevenly. Other variations in laminating pressure and / or laminating temperature over the lamination process are also possible.

[0022] Preferably, one or more of the functional elements are formed by an element that performs an electrical and / or optical function, in particular by a light guide. Such a light guide consists in particular of a plastic, preferably of one or more PMMA (PMMA = polymethyl methacrylate) and / or one or more PC (PC = polycarbonate) and / or glass. Furthermore, it is possible for such a light guide or a plurality of such light guides to be arranged and / or applied and / or formed in and / or between and / or on one or more sensor films of the one or more sensor films.

[0023] It has proven advantageous to design one or more of the functional elements as light guides. This enables, in particular, targeted light guidance in the multilayer body in combination with the formation of the surface relief in the first surface of the substrate.

[0024] Furthermore, it is possible to use fabrics made of natural, plant-based and / or synthetic fabrics, preferably glass fiber fabrics and scrims, more preferably plant-based relief-forming sheets, such as wood veneers, as functional elements, whereby the fabric reliefs corresponding to the fabrics or the fabric contours are formed, in particular additionally, in the first surface of the substrate as part of the surface relief or as a surface relief.

[0025] It is possible that the application of the one or more sensor films to the second surface of the substrate is preferably carried out by means of lamination, wherein the lamination temperature is preferably between 80°C and 300°C, in particular between 100°C and 300°C, preferably between 120°C and 240°C, wherein in particular the lamination speed is between 0.125 m / min and 10 m / min, preferably between 0.25 m / min and 7.5 m / min, particularly preferably between 0.125 m / min and 5 m / min.

[0026] "Laminating temperature" is understood to mean, in particular, the surface temperature or the temperature at a point or area inside one or more sensor films and / or the substrate during lamination.

[0027] It is possible for the at least one sensor film of the one or more sensor films, in particular the at least one sensor film of the one or more sensor films comprising at least one decorative layer of the one or more decorative layers, to be applied to the second surface of the substrate, in particular to the second surface of the substrate comprising at least one decorative layer of the one or more decorative layers, preferably by means of an embossing process, a rolling process and / or a back-injection process.

[0028] In particular, one or more decorative layers of the one or more decorative layers have a layer thickness between 0.01 mm and 10 mm, in particular between 0.1 mm and 2.5 mm, preferably between 0.25 mm and 1.25 mm, and / or between 0.1 mm and 10 mm, in particular between 0.25 mm and 2.5 mm, preferably between 0.25 mm and 1.25 mm.

[0029] It has proven advantageous to apply or apply the one or more sensor films preferably to the second surface of the substrate, in particular a substrate comprising one or more decorative films, preferably by means of embossing processes, rolling processes and / or back-injection processes.

[0030] Furthermore, it is also possible that during thermoforming of the layer sequence the surface relief is formed in particular by means of deep drawing and heating of the substrate, wherein the substrate is preferably heated to a surface temperature between 80°C and 300°C, in particular between 90°C and 250°C, preferably between 100°C and 300°C, wherein in particular the core temperature of the substrate is between 120°C and 160°C, preferably between 100°C and 180°C, particularly preferably between 80°C and 200°C, and / or wherein a pressure, in particular an overpressure between 1 bar and 6 bar, in particular between 2 bar and 5 bar, preferably between 2 bar and 3.5 bar, is applied. This pressure acts on the substrate in particular from one of the two sides. From the corresponding other substrate side, a vacuum, i.e. a negative pressure, is preferably additionally applied, which is preferably between 0.1 bar and 0.9 bar, in particular between 0.2 bar and 0.8 bar.For example, an overpressure can act from the front of the substrate and a negative pressure from the back of the substrate or vice versa, that is to say that a negative pressure is preferably applied from the front of the substrate and an overpressure from the back of the substrate.

[0031] The term "lamination temperature" refers in particular to the temperature at a point or area inside the layer sequence, in particular at the geometric center of the layer sequence, during deep drawing or heating of the layer sequence.

[0032] This makes it possible in particular for the surface relief to be preferably formed in the first surface of the substrate, wherein the surface relief is preferably formed by the shaping, in particular by contour and / or height relief, of the one or more sensor films.

[0033] Furthermore, this preferably achieves that the previous additional marking of the sensor area, for example, by subsequently applied pictograms, is replaced by optical and / or haptic surface reliefs, which are or are formed on the first surface of the substrate. Such a novel marking, in particular, does not require an additional process step, since these are formed by the one or more sensor films and / or further films, layers, labels, in particular plastic labels, and / or elements, in particular functional elements, preferably 3D elements, during thermoforming and can thus be integrated into the surface design of the resulting multilayer body.

[0034] Furthermore, new design freedoms are preferably created in such a way that the one or more sensor films and / or further films, layers, labels, in particular plastic labels, and / or elements, in particular functional elements, preferably 3D elements, can be integrated harmoniously into the multi-layer body.

[0035] Furthermore, this preferably achieves that, in contrast to the previous additional markings of the sensor area, for example by subsequently applied pictograms, which are "worn off" or worn out over time, the marking according to the invention is more resistant to such long-term stresses or long-term use.

[0036] Furthermore, this particularly ensures that the position and geometric extent of the "active" sensor area, particularly in the plane spanned by the multilayer body and / or particularly perpendicular to this plane, can be detected haptically and / or optically. The undesirable effect of the tracing of one or more sensor films and / or other films, layers, labels, particularly plastic labels, and / or elements, particularly functional elements, preferably 3D elements, is preferably utilized to avoid the need to apply additional "virtual" subsequently applied control elements such as buttons or switches as decoration, such as subsequently applied pictograms.

[0037] To date, sensors have been bonded primarily behind deep-drawn parts, requiring the end customer and / or user to be specifically informed of the sensory functionality, as this functionality would otherwise remain undetected. The user and / or end customer is regularly alerted to the sensory functionality by means of separate, subsequently applied pictograms, which are preferably located at the corresponding positions on the side of the component facing the user. In particular, this generally requires an additional process step for applying or creating such pictograms.

[0038] Preferably, the layer sequence, in particular a layer sequence comprising one or more decorative films, is formed from one or more PC and / or one or more PMMA.

[0039] It is further possible that the layer sequence, in particular the layer sequence comprising the one or more decorative films, is preferably not formed from glass fiber-filled or plastic fiber-filled PC and / or PMMA.

[0040] Furthermore, it is possible that the substrate, in particular the substrate comprising the one or more decorative films, is in particular not formed from blends or mixtures of ABS and / or PC and / or pure ABS and / or pure polyamide and / or blends or mixtures thereof.

[0041] During thermoforming of the layer sequence, the surface relief is preferably formed by laminating the layer sequence, wherein the laminating temperature is preferably between 80°C and 300°C, in particular between 100°C and 260°C, preferably between 120°C and 240°C, wherein in particular the laminating speed is between 0.125 m / min and 10 m / min, preferably between 0.25 m / min and 10 m / min, particularly preferably between 0.5 m / min and 10 m / min, and / or preferably between 0.25 m / min and 7.5 m / min.

[0042] It has proven advantageous that a substrate is preferably provided as the substrate which preferably has a layer thickness, in particular an average layer thickness, of between 125 µm and 3500 µm, in particular between 400 µm and 1500 µm, preferably between 600 µm and 1100 µm, before thermoforming and / or that a substrate is preferably provided as the substrate which preferably has a layer thickness, in particular an average layer thickness, of between 125 µm and 3500 µm, in particular between 400 µm and 1500 µm, preferably between 600 µm and 1100 µm, after thermoforming.

[0043] Preferably, the substrate, in particular the substrate comprising the one or more decorative layers, consists of a material, preferably a solid material, without air inclusions.

[0044] It has proven to be advantageous if the substrate, in particular the substrate comprising the one or more decorative layers, is not made of foam and / or a foam-like material or substance, since, for example, the mechanical behavior of a foam and / or a foam-like material is unknown or can only be determined with great effort and the inclusions enclosed or contained in the foam or the foam-like material, in particular air inclusions, negatively influence the electrical properties, in particular the electrical conductivity and the capacitance, of the one or more sensor films.

[0045] Furthermore, it is possible that a substrate having a first melting temperature is preferably provided as the substrate and a sensor film having a second melting temperature is preferably provided as the sensor film, wherein in particular the first melting temperature is lower, preferably lower by a factor of 1 to 3, more preferably lower by a factor of 1.3 to 2.5, than the second melting temperature, wherein the substrate preferably consists of a biaxially stretched PET or polyethylene terephthalate.

[0046] The term "melting temperature" or melting point is understood in particular to mean the temperature at which a material and / or substance melts and, as a result, preferably changes from a solid state to a liquid state.

[0047] It is also possible that a substrate having a first softening temperature is preferably provided as the substrate and a sensor film having a second softening temperature is preferably provided as the sensor film, wherein in particular the first softening temperature is lower, preferably lower by a factor of 1 to 3, more preferably lower by a factor of 1.3 to 2.8, than the second softening temperature.

[0048] "Softening temperature" or softening point is understood here in particular to be the temperature at which a material and / or substance begins to flow, preferably under predetermined conditions. In this case, the material and / or substance is heated in particular until it changes from the solid state to the liquid state. Softening temperature is understood here in particular to be the Vicat softening temperature (VST), preferably measured with a test force of 50 N, i.e., preferably VSTB.

[0049] It has proven advantageous that the variable process parameters, such as temperature and / or pressure, in particular mechanical pressure, of the thermoforming process are preferably predetermined such that the softening or plasticization of the substrate, in particular the substrate comprising one or more decorative films, occurs at lower temperatures, in particular softening temperatures and / or melting temperatures, and / or pressures, in particular mechanical pressures, than the softening or plasticization of the one or more sensor films.

[0050] Tests have shown that the melting temperature of the substrate, in particular the substrate comprising the one or more decorative films, is preferably lower than the melting temperature of the one or more sensor films. For example, the melting temperature of a substrate, in particular a substrate comprising one or more decorative films, consisting of PC is between 220°C and 230°C, and / or, for example, the melting temperature of one or more sensor films consisting of PET is 255°C, in particular between 250°C and 260°C.

[0051] Furthermore, tests have shown that the change in the height of the provided substrate with a laminated sensor, preferably a substrate with a laminated sensor with a predetermined layer thickness, due to thermoforming has in particular a functional relationship to the layer thickness of the applied sensor film, wherein this functional relationship is in particular a second degree polynomial of the form y = a x 2< + b x + c, preferably with the parameters a = 0.0035; b = 0.4832, c = 38.19; and preferably the variables x = layer thickness of the applied sensor label, y = height of the formation at the location of the sensor label in comparison to the remaining substrate surface without the sensor label after thermoforming.

[0052] It has been shown here that the one or more sensor films act in particular as heat insulators during thermoforming, preferably during deep drawing. During thermoforming of the layer sequence, the layer sequence is preferably heated from the direction of the second surfaces of the one or more sensor films or from the second surface of the substrate, so that the heat flow into the substrate, in particular the substrate comprising the one or more decorative films, is preferably smaller in the one or more regions in which the one or more sensor films rest on the first surface of the one or more sensor films than in the regions in which the one or more sensor films do not rest on the first surface of the one or more sensor films.

[0053] Preferably, the layer sequence before thermoforming has a curvature with a minimum or maximum radius of curvature and / or with an average radius of curvature of not less than 1.5 mm, preferably not less than 1 mm.

[0054] "Curvature" refers specifically to a local deviation of a curve from a straight line. The curvature of a curve refers specifically to a change in direction per traversed length and / or distance of a sufficiently short curve segment or curve profile. The curvature of a straight line is zero everywhere. A circle with a radius r has the same curvature everywhere, namely 1 / r. For most curves, the curvature changes from one point to the next. In particular, the curvature changes continuously from one point to the next, so that the curves, in particular, exhibit no kinks and / or discontinuities. The curvature of a curve at a point P thus indicates how much the curve deviates from a straight line in the immediate vicinity of point P. The magnitude of the curvature is called the radius of curvature, and this corresponds to the inverse of the magnitude of a local radius vector.The radius of curvature is the radius of the circle that best approximates the point of contact and / or tangency P of a curve in a local neighborhood.

[0055] Preferably, the layer sequence is modified during thermoforming such that the layer sequence preferably after thermoforming has a curvature with a minimum or maximum radius of curvature and / or with an average radius of curvature of not less than 1.5 mm, preferably not less than 1 mm.

[0056] It is preferably nevertheless possible to integrate optical markings for the user in the form of pictograms incorporated or applied in decorative layers into the multi-layer body in such a way that these pictograms are arranged in the sensor area or overlap the sensor area and / or are arranged outside the sensor area.

[0057] Furthermore, it is possible to provide a substrate as the substrate and / or at least one sensor film, preferably at least one sensor film, comprising one or more decorative layers, wherein the decorative layers in particular have one or more pictograms in one or more regions, preferably in the sensor region. Preferably, one or more of the one or more pictograms overlap or complement each other to form an overall pictogram.

[0058] In particular, one or more of the pictograms of the one or more pictograms or the overall pictogram are each designed as a motif, a graphically designed outline, a figurative representation, a picture, a visually recognizable image, a symbol, a logo, a portrait, a pattern, an alphanumeric character, a text and / or the like.

[0059] It is also possible to form the surface relief formed in the first surface of the substrate in such a way that it forms one or more pictograms which can be detected optically and / or haptically, in particular by means of a human fingertip or thumbtip.

[0060] It is possible for the substrate to have, in particular, one or more transparent regions, wherein, in particular, the transmittance of the substrate between the first surface of the substrate and the second surface of the substrate in the one or more transparent regions in a wavelength range visible to the human eye is greater than 1%, preferably greater than 2%, more preferably greater than 4%, and / or less than 99%, preferably less than 95%, more preferably less than 92%.

[0061] Furthermore, it is possible for one or more of the decorative films to have, in particular, pigmented and / or colored and / or metallized and / or partially metallized layers. Preferably, partially transparent or transparent decorative films are combined with transparent sensor films in order to provide, at least in some regions, a degree of transmittance or light permeability and / or a controlled and / or predetermined degree of emissivity, particularly when viewing the multilayer body from the first surface.

[0062] Preferably, the transparent regions are clearly transparent, meaning in particular uncolored and / or have the color of the substrate, or colored, matte with fillers, and / or colored, or are in particular a combination, in particular a region-wise combination of region-wise different transparencies and / or colorations, of the above properties. Such clearly transparent regions comprise in particular one or more regions of the sensor region or the entire sensor region.

[0063] It is possible for the multilayer body to have transparent regions extending over all layers so that, for example, a light source can be detected by an observer in transmitted light through the multilayer body.

[0064] In particular, the gloss levels of the one or more decorative layers or the substrate or the one or more sensor films are between 2 @60°, in particular 2 GU at a measuring angle of 60°, and 160 @60°, in particular 160 GU at a measuring angle of 60°, where "GU" is to be understood in particular as "gloss units".

[0065] It is further possible to arrange one or more or all decorative films, pictograms, plastic labels, functional elements, transparent areas and / or sensor films in register with each other or with one or more or all decorative films, pictograms, plastic labels, functional elements, transparent areas and / or sensor films, in particular to form a registered overall design.

[0066] Register or registration, or register accuracy or registration precision, is understood to mean the positioning accuracy of two or more elements and / or layers relative to one another. The register accuracy should be within a specified tolerance and as small as possible. At the same time, the register accuracy of several elements, sub-areas, in particular one or more first sub-areas, films and / or layers relative to one another is an important feature for increasing process reliability. The precise positioning is achieved in particular by means of markings, in particular by means of sensory, preferably optically detectable registration marks or register marks. These markings, in particular registration marks or register marks, preferably represent either special separate elements or areas or layers or are preferably themselves part of the elements or areas or layers to be positioned.

[0067] Preferably, the one or more sensor films are aligned using one or more templates to the alignment and / or positioning of the one or more decorative layers. The sensor films are aligned, in particular, to register marks present in the decorative layers and are preferably positioned in this way depending on the design. Furthermore, it is particularly possible to align the sensor films to pictograms of the decorative layers, which are preferably printed separately and / or on the back and / or from the second surface of the substrate and / or are already present in the decorative layers, such as, for example, closed geometric pictograms, in particular circles and / or polygons.

[0068] It is possible that a substrate is preferably provided as the substrate which comprises one or more layers selected from: layers comprising pigments, color layers, metal layers, metallized layers, in particular partially metallized layers, transparent layers, translucent layers, opaque layers.

[0069] According to the invention, it is provided that the one or more sensor films each have one or more sensor elements, in particular capacitive and / or resistive sensor elements, in the at least one sensor region and that the one or more sensor films each have at least one connection region and / or contact region for contacting one or more of the sensor elements.

[0070] It is also possible that a sensor film is preferably provided as the sensor film, which in particular has a base film and one or more electrically conductive layers applied and / or introduced onto the base film, in particular consisting of a metallic material.

[0071] Preferably, the one or more electrically conductive layers in the sensor region form one or more sensor electrodes for forming one or more of the sensor elements, in particular for forming one or more capacitive sensor elements and / or one or more resistive sensor elements and / or that the one or more electrically conductive layers preferably have one or more contact electrodes in the connection region and / or contact region for contacting, in particular for electrical contacting, the one or more sensor electrodes.

[0072] In particular, the one or more sensor electrodes, in particular one or more active sensor regions of the one or more sensor electrodes, have a transparency with a transmittance of more than 60%, in particular more than 80%, for the human eye and / or are each formed by a network of thin conductor tracks with a conductor track width between 3 µm and 60 µm, in particular between 4 µm and 60 µm, particularly preferably between 4 µm and 50 µm.

[0073] In particular, a sensor film is provided as the sensor film, which preferably has a layer thickness between 10 µm and 300 µm, in particular between 50 µm and 200 µm, preferably between 60 µm and 150 µm.

[0074] It has proven advantageous for the layer sequence to have a capacitance of at most 200 pF, preferably at most 150 pF, and more preferably at most 100 pF, at least in the sensor region. This enables, in particular, a touch function in the sensor region, preferably by means of a human fingertip and / or a human thumbtip.

[0075] In particular, it is also possible for sensor cells without a tail lead, preferably small sensor cells without a tail lead, more preferably directly contactable sensor cells, to have a capacitance of a maximum of 7 pF, in particular a maximum of 5 pF, particularly preferably a maximum of 3 pF, and / or for sensors with a tail, in particular large sensors with a tail, to have a capacitance of 12 pF to 70 pF, preferably if they are injected, wherein the capacitances are preferably even higher if the decorative layers are slightly conductive.

[0076] The single-layer or multi-layer substrate can optionally be printed on one or both sides. To enable the touch function or the sensor function of the applied sensor film or films, it is advantageous for the multi-layer body to have a capacitance of a maximum of 200 pF, with the measured value preferably taking into account the intrinsic capacitance of a measuring device, in particular a measuring head. The measuring device can, for example, be a so-called "self-capacitance" measuring head, which measures the intrinsic capacitance of a structure connected to the measuring head.

[0077] Furthermore, it is advantageous if the values ​​corrected by the measuring device preferably have a maximum capacitance of 150 pF, in particular to enable sufficient sensor sensitivity and / or sensor functionality through the layers of the multi-layer body.

[0078] The measurement method preferably involves a capacitive test or measurement of an ohmically connected film test piece. The film test piece, for example, a touch sensor, has, in particular, connection areas and / or contact areas for contacting, which are preferably connected to touch surfaces or sensor electrodes via thin conductor tracks. The touch surfaces or sensor electrodes form a first half and a second half of a coplanar capacitor.

[0079] Furthermore, the measuring head preferably comprises contact pins for ohmic contacting, a resonant circuit chip, which has a specific frequency, in particular depending on the connected capacitance, and evaluation electronics, which preferably determines the output frequency and transmits it, in particular, to a connected processing unit. The frequency determined in this way is therefore preferably a measure of the additional capacitance connected to the measuring head. The additional capacitance connected is, in particular, the capacitance of the connected coplanar capacitor or the touch sensor.

[0080] The capacitance of the coplanar capacitor preferably depends on the type of coplanar plates present, for example, their area, shape, and / or spacing, as well as, in particular, on dielectric or conductive environments and / or layers above and below the respective coplanar plates. If a conductive object, such as a human finger, is then approached, the coplanar capacitor or touch sensor preferably changes its measurable capacitance depending on the distance between the conductive object and the coplanar capacitor or touch sensor. This particularly tests the functionality, especially the faultlessness, of the coplanar capacitor or touch sensor. Preferably, a non-touched capacitance is sufficient as a functional criterion if a certain minimum value is reached.

[0081] Preferably, a similar sensor, particularly in terms of design, is used to determine the dielectric or conductive properties of a printed layer. For this purpose, comparative measurements are preferably first performed on known materials, such as a 1 mm thick PMMA plate as a non-conductive material and, for example, a metallized foil or carbon layer with known sheet resistances, particularly as a fully conductive material. High-resistance conductive printed layers then preferably lie between these two materials with their measured values, which makes it possible, in particular, to draw conclusions about their conductivity and thus their touch interference susceptibility.

[0082] It is possible for the sensor region to comprise at least one edge region at least partially surrounding the sensor region, in particular an annular edge region, in particular an annular edge region, in which the one or more sensor electrodes are not present, wherein the edge region preferably surrounds the circumference of the sensor region from the outside or from the inside and / or follows the circumference of the sensor region and / or completely or partially overlaps the circumference of the sensor region.

[0083] Preferably, the sensor area or the active touch area is located only within the surface relief and in particular not on the surface relief itself.

[0084] Furthermore, it is possible for the edge region to preferably have a width, in particular a radial width, of between 0.25 mm and 5 mm, preferably between 0.5 mm and 5 mm, and / or for the annular edge region, in particular the circular edge region, to preferably have a ring width of between 0.25 mm and 5 mm, preferably between 0.5 mm and 2 mm. Preferably, the edge region does not have any elements for contacting one or more sensor elements arranged in the sensor region.

[0085] It is also possible that the surface relief formed on the first surface of the substrate is preferably haptically and / or optically detectable and / or that the surface relief formed on the first surface of the substrate is preferably haptically but not optically detectable or is preferably optically but not haptically detectable.

[0086] In particular, experiments have shown that the surface relief formed on the first surface of the substrate has a maximum height difference and / or an average height difference between a local minimum of the surface relief or a global minimum of the surface relief and a local maximum of the surface relief or a global maximum of the surface relief, which is less than 5000 µm, in particular less than 2000 µm, preferably less than 1000 µm.

[0087] Preferably, the surface relief formed on the first surface of the substrate has a maximum height difference and / or an average height difference between a local minimum of the surface relief or a global minimum of the surface relief and a local maximum of the surface relief or a global maximum of the surface relief, which is greater than or equal to 50 µm, in particular greater than 25 µm, preferably greater than 10 µm.

[0088] It is possible that the surface relief formed on the first surface of the substrate is preferably formed as Braille, in particular as one or more letters, one or more numbers, one or more words, and / or one or more sentences in Braille.

[0089] Preferred embodiments of the multilayer body are mentioned below.

[0090] Preferably, the one or more sensor films in the sensor area, in particular in regions or over the entire area, have one or more films and / or one or more layers selected from: base film, plastic label, functional elements, in particular light guide, decorative layer, electrically conductive layer, in particular metallic layer, adhesive layer, adhesion promoter layer, wherein the one or more electrically conductive layers each have one or more sensor electrodes and / or one or more contact electrodes.

[0091] It is possible for the one or more sensor films to have one or more sensor electrodes and / or one or more contact electrodes in the sensor region, wherein the sensor electrodes and / or the contact electrodes, in particular projected onto the plane spanned by the first surface of the at least one sensor film, are arranged next to one another and / or do not overlap one another and / or, in particular when viewed parallel to a surface normal defined by the plane of the multi-layer body, one or more sensor electrodes of the one or more sensor electrodes overlap with one or more contact electrodes of the one or more contact electrodes.

[0092] Furthermore, it is possible that the surface relief, in particular projected onto the plane spanned by the first surface of the at least one sensor film, is at least partially composed of one or more straight, curved, circular-arc-shaped and / or circular elevations and / or depressions, in particular in the sensor area.

[0093] It is also possible that the surface relief, in particular projected onto the plane spanned by the first surface of the at least one sensor film, is formed at least partially with one or more linear, spiral and / or elliptical elevations and / or depressions, in particular in the sensor region.

[0094] Furthermore, it is also possible that the surface relief, in particular in the sensor area, is designed such that one or more elevations of the one or more elevations and / or one or more depressions of the one or more depressions, in particular in the sensor area, each have a constant or varying flank angle and / or a constant or varying width and / or a constant or varying height or depth and / or a constant or varying curvature.

[0095] In particular, the shape of one or more elevations of the one or more elevations and / or one or more depressions of the one or more depressions, in particular projected onto the plane spanned by the first surface of the at least one sensor film, preferably in the sensor area, is in each case selected or combined from: line, straight line, motif, image, triangle, wave, square, polygon, curved line, circle, oval, trapezoid, parallelogram, rhombus, cross, sickle, branch structure, star, ellipse, fractal pattern, random pattern, pseudo-random pattern, wherein the one or more elevations and / or the one or more depressions in particular overlap and / or complement one another.

[0096] Preferably, one or more elevations of the one or more elevations and / or one or more depressions of the one or more depressions are formed over the course, in particular in the plane spanned by the first surface of the at least one sensor film, of the respective elevations and / or depressions in such a way that one or more of the heights of the elevations and / or one or more depths of the depressions, in particular perpendicular to the plane spanned by the second surface of the substrate, do not have a variation or at least have a variation in sections, wherein the variation is selected from: wave-shaped, symmetrical, asymmetrical, periodic, aperiodic, discrete, continuous, stepped.

[0097] The invention is explained below using several exemplary embodiments with the aid of the accompanying drawings. In the drawings: Fig. 1 shows a schematic representation of a layer sequence Fig. 2 shows a schematic representation of a multi-layer body Fig. 3 shows a schematic representation of a layer sequence Fig. 4 shows a schematic representation of a multi-layer body Fig. 5 shows a schematic representation of a diagram Fig. 6 shows a schematic representation of a multi-layer body Fig. 7 shows a schematic representation of a multi-layer body Fig. 8 shows a schematic representation of a multi-layer body Fig. 9 shows a schematic representation of a multi-layer body Fig. 10 shows a schematic representation of a multi-layer body Fig. 11 shows a schematic representation of a multi-layer body Fig. 12 shows a schematic representation of a sensor film Fig. 13 shows a schematic representation of a sensor film Fig. 14 shows a schematic representation of a sensor film Fig. 15 shows a schematic representation of a sensor film Fig.16 shows a schematic representation of a substrate Fig. 17 shows a schematic representation of a layer sequence Fig. 18 shows a schematic representation of a multi-layer body Fig. 19 shows a schematic representation of a multi-layer body Fig. 20 shows a schematic representation of a multi-layer body.

[0098] Fig. 1 shows a layer sequence 4 comprising a substrate 2 and a sensor film 3 in cross-section. The sensor film 3 lies on the substrate 2, with the first surface 3a of the sensor film 3 lying on the second surface of the substrate 2.

[0099] Furthermore, it is possible that as substrate 2 in particular a substrate 2 having a first melting temperature is provided and as sensor film 3 a sensor film 3 having a second melting temperature is provided, wherein in particular the first melting temperature is lower, preferably lower by a factor of 1 to 3, more preferably lower by a factor of 1.3 to 2.5, than the second melting temperature.

[0100] In particular, a substrate 2 having a first softening temperature is provided as substrate 2 and a sensor film 3 having a second softening temperature is provided as sensor film 3, wherein in particular the first softening temperature is lower, preferably lower by a factor of 1 to 3, more preferably lower by a factor of 1.3 to 2.8, than the second softening temperature.

[0101] The Figure 2shows a multilayer body 1 comprising a substrate 2 and a sensor film 3 in cross section, wherein the first surface 2a of the substrate 2 forms a surface relief 5. Here, the surface relief 5 is determined by the shape 6 of the sensor film 3.

[0102] The multilayer body 1 is preferably produced by a process comprising the following steps: Providing a single-layer or multi-layer substrate 2 with a first surface 2a and a second surface 2b, Providing one or more sensor films 3, each comprising at least one sensor region 30 and having a first surface 3a and a second surface 3b facing away from the first surface 3a, Applying the one or more sensor films 3 to the second surface 2b of the substrate 2 such that the first surface 3a of the respective sensor film rests at least partially on the second surface 2b of the substrate 2, Thermoforming a layer sequence 4 comprising the substrate 2 and the one or more sensor films 3 applied to the second surface 2b of the substrate 2 such that during thermoforming a surface relief 5 is formed on the first surface 2a of the substrate 2, which surface relief 5 is formed by the shaping 6, in particular contour and / or height relief,one or more of the one or more sensor foils 3 is intended. ,

[0103] In particular, the Figure 1 here the layer sequence 4, which results from the application of the sensor film 3 to the second surface 2b of the substrate 2, wherein the first surface 3a of the sensor film 3 rests on the second surface 2b of the substrate 2.

[0104] Preferably, a substrate 2 is provided which preferably has a layer thickness, in particular an average layer thickness, between 125 µm and 3500 µm, in particular between 400 µm and 1500 µm, preferably between 600 µm and 1100 µm, before thermoforming.

[0105] According to the invention, a substrate 2 is provided which, after thermoforming, preferably has a layer thickness, in particular an average layer thickness, between 125 µm and 3500 µm, in particular between 400 µm and 1500 µm, preferably between 600 µm and 1100 µm.

[0106] Preferably, a sensor film 3 is provided which in particular has a layer thickness between 10 µm and 300 µm, in particular between 50 µm and 200 µm, preferably between 60 µm and 150 µm.

[0107] It is possible that the application of the sensor film 3 to the second surface 2b of the substrate 2 is carried out in particular by means of lamination, wherein the lamination temperature is between 80°C and 300°C, in particular between 100°C and 300°C, preferably between 120°C and 240°C, wherein in particular the lamination speed is between 0.125 m / min and 10 m / min, preferably between 0.25 m / min and 7.5 m / min, particularly preferably between 0.125 m / min and 5 m / min.

[0108] Further preferred is the Figure 2 the multilayer body 1 after thermoforming of the Figure 1shown layer sequence 4 comprising the substrate 2 and the sensor film 3 applied to the second surface 2b of the substrate 2, wherein during thermoforming a surface relief 5 is formed on the first surface 2a of the substrate 2, which is determined by the shape 6 of the sensor film 3.

[0109] It has proven particularly advantageous that during thermoforming of the layer sequence 4 the surface relief 5 is formed by deep drawing and heating of the substrate 2, wherein the substrate is preferably heated to a surface temperature between 80°C and 300°C, in particular between 90°C and 250°C, preferably between 100°C and 300°C, wherein in particular the core temperature of the substrate is between 120°C and 160°C, preferably between 100°C and 180°C, particularly preferably between 80°C and 200°C, and / or wherein a pressure, in particular an overpressure between 1 bar and 6 bar, in particular between 2 bar and 5 bar, preferably between 2 bar and 3.5 bar, is applied. This pressure acts on the substrate in particular from one of the two sides.A vacuum, i.e., a negative pressure, is preferably applied from the corresponding other substrate side, which is preferably between 0.1 bar and 0.9 bar, in particular between 0.2 bar and 0.8 bar. For example, an overpressure can be applied from the front side of the substrate and a negative pressure from the back side of the substrate, or vice versa, meaning that a negative pressure is preferably applied from the front side of the substrate and an overpressure from the back side of the substrate.

[0110] It is preferably also possible that during thermoforming of the layer sequence 4 the surface relief 5 is formed by laminating the layer sequence 4, wherein the laminating temperature is preferably between 80°C and 300°C, in particular between 100°C and 260°C, preferably between 120°C and 240°C, wherein in particular the laminating speed is between 0.125 m / min and 10 m / min, preferably between 0.25 m / min and 10 m / min, particularly preferably between 0.5 m / min and 10 m / min, and / or preferably between 0.25 m / min and 7.5 m / min.

[0111] It is also possible for the multi-layer body 1 to comprise a single-layer or multi-layer substrate 2 having a first surface 2a and a second surface 2b and one or more sensor films 3, each comprising at least one sensor region and having a first surface 3a and a second surface 3b facing away from the first surface 3a, wherein the one or more sensor films 3 are arranged on the second surface 2b of the substrate 2, wherein the first surface 3a of the sensor film 3 rests on the second surface 2b of the substrate 2, and wherein a surface relief 5 is formed on the first surface 2a of the substrate 2, which is determined by the shape 6, in particular contour and / or height relief, of one or more of the one or more sensor films 3.

[0112] Preferably, a substrate 2 is provided as substrate 2 and / or a sensor film 3 is provided as sensor film 3, which comprise one or more decorative layers, wherein in particular the decorative layers have one or more pictograms in one or more areas, preferably in the sensor area, wherein one or more pictograms of the one or more pictograms overlap or complement each other to form an overall pictogram.

[0113] The Figure 3 shows a layer sequence 4 comprising a sensor film 3 and a substrate 2 in cross-section, wherein the substrate 2 has a decorative layer 41. Here, the decorative layer 41 is preferably applied to the surface of the substrate 2 facing the sensor film 3 or to the substrate 2 from the side of the second surface 2b of the substrate 2. The first surface 3a of the sensor film 3 lies, in particular, in regions on the second surface 2b of the substrate 2.

[0114] In particular, the decorative layer 41 has a layer thickness between 0.01 mm and 10 mm, in particular between 0.1 mm and 2.5 mm, preferably between 0.25 mm and 1.25 mm, and / or between 0.1 mm and 10 mm, in particular between 0.25 mm and 2.5 mm, preferably between 0.25 mm and 1.25 mm.

[0115] It is possible that the sensor film 3 is applied to the second surface of the substrate 2 comprising the decorative layer 41, in particular by means of an embossing process, a rolling process and / or a back-injection process.

[0116] It is also possible that a substrate 2 is preferably provided as substrate 2 which comprises one or more layers selected from: layers comprising pigments, color layers, metal layers, metallized layers, in particular partially metallized layers, transparent layers, translucent layers, opaque layers.

[0117] The Figure 4shows a multilayer body 1 comprising a substrate 2 in cross section, wherein the substrate 2 has a decorative layer 41 applied to the surface of the substrate 2 facing the sensor film 3, and a sensor film 3, wherein the first surface 2a of the substrate 2 forms a surface relief 5. Here, the surface relief 5 is determined by the shape 6 of the sensor film 3.

[0118] Preferably, the shape 6 of the at least one sensor film 3 is modified when providing the sensor film 3.

[0119] Further preferred is the Figure 3 here the layer sequence 4, which results from the application of the sensor film 3 to the second surface 2b of the substrate 2, wherein the first surface 3a of the sensor film 3 rests at least partially on the second surface 2b of the substrate 2.

[0120] Particularly preferred is the Figure 4the multilayer body 1 after thermoforming of the Figure 3 shown layer sequence 4 comprising the substrate 2 and the sensor film 3 applied to the second surface 2b of the substrate 2, wherein during thermoforming a surface relief 5 is formed on the first surface 2a of the substrate 2, which is determined by the shape 6 of the sensor film 3.

[0121] In this case, the surface relief 5 formed on the first surface 2a of the substrate 2 during thermoforming has a height difference h to the original plane of the first surface 2a of the substrate 2 in the Figure 3 shown layer sequence 4. The layers in the Figure 4 The height difference shown is in particular the difference between the absolute maximum of the surface relief 5 and the absolute minimum of the surface relief 5 along a direction which is in particular parallel to the direction defined by the plane of the Figure 4shown multilayer body 1. Preferably, the absolute minimum of the surface relief 5 corresponds to the plane spanned by the second surface 2a of the substrate 2 outside the surface relief 5.

[0122] In particular, experiments have shown that the surface relief 5 formed on the first surface 2a of the substrate 2 preferably has a maximum height difference and / or an average height difference between a local minimum of the surface relief 5 or a global minimum of the surface relief 5 and a local maximum of the surface relief 5 or a global maximum of the surface relief 5, which is less than 5000 µm, in particular less than 2000 µm, preferably less than 1000 µm.Furthermore, it is possible that the surface relief 5 formed on the first surface 2a of the substrate 2 preferably has a maximum height difference and / or an average height difference between a local minimum of the surface relief 5 or a global minimum of the surface relief 5 and a local maximum of the surface relief 5 or a global maximum of the surface relief 5, which is greater than or equal to 50 µm, in particular greater than 25 µm, preferably greater than 10 µm.

[0123] The Figure 5 and Table 1 show the results of a series of measurements as a function of the variables x and y, with the measurement series comprising four measurement points (indicated by squares). The variable x corresponds to the layer thickness of the sensor film 3 applied to the substrate 2, and the variable y corresponds to the layer thickness of the substrate 2 after thermoforming. In particular, the substrate 2 had a layer thickness of y 0 = 750 µm before thermoforming. Table 1 Layer thickness of substrate before thermoforming Layer thickness of sensor film Height h (especially h shown in Fig. 4 ) y 0 [µm] x [µm] y 1 [µm] 750 98 122 750 170 214 750 250 381 750 500 1150

[0124] It has been shown in particular that the change in the height of the provided substrate with a laminated sensor, preferably a substrate with a laminated sensor with a predetermined layer thickness, as a result of thermoforming has in particular a functional relationship to the layer thickness of the applied sensor film, wherein this functional relationship is in particular a second degree polynomial of the form y = a x 2< + b x + c, preferably with the parameters a = 0.0035; b = 0.4832, c = 38.19; and preferably the variables x = layer thickness of the applied sensor label, y = height h of the formation at the location of the sensor label in comparison to the remaining substrate surface without the sensor label after thermoforming.

[0125] The Figure 6shows a multilayer body 1 comprising a sensor film 3 and a substrate 2 in cross-section, wherein the sensor film 3 is applied in regions to the second surface 2b of the substrate 2. Furthermore, a surface relief 5 is formed in the first surface 2a of the substrate 2. The multilayer body 1 and in particular the sensor film 3 further have a sensor region 30, which is surrounded in particular by one closed or two non-contiguous edge regions 30'. Preferably, the edge region 30' is arranged in a ring shape, in particular annular, around the sensor region 30, wherein the sensor region 30 is in particular circular in shape.

[0126] In particular, the sensor film 3 has one or more sensor elements, in particular capacitive and / or resistive sensor elements, in the sensor region 30. Further preferably, the sensor film 3 has a connection region and / or contact region for contacting, in particular for electrical contacting, one or more of the sensor elements.

[0127] Preferably, a sensor film 3 is provided which has a base film and one or more electrically conductive layers applied and / or introduced onto the base film, in particular consisting of a metallic material.

[0128] It is possible for the one or more electrically conductive layers in the sensor region 30 to form one or more sensor electrodes for forming one or more of the sensor elements, in particular for forming one or more capacitive sensor elements and / or one or more resistive sensor elements, and / or for the one or more electrically conductive layers in the connection region and / or contact region to have one or more contact electrodes for contacting the one or more sensor electrodes.

[0129] Furthermore, it is possible for the sensor region 30 to comprise at least one at least partially enclosing edge region, in particular an annular edge region, in particular an annular edge region, in which the one or more sensor electrodes are not present, wherein the edge region preferably encloses the circumference of the sensor region 30 from the outside or from the inside and / or follows the circumference of the sensor region 30 and / or completely or partially overlaps the circumference of the sensor region 30, wherein the edge region preferably has a width, in particular a radial width, between 0.25 mm and 5 mm, preferably between 0.5 mm and 5 mm, and / or that the annular edge region, in particular the annular edge region, preferably has a ring width between 0.25 mm and 5 mm, preferably between 0.5 mm and 2 mm.

[0130] The Figure 7 shows the Figure 6shown multilayer body in cross-section, except that the present multilayer body 1 has functional elements 33 in the edge regions 30', which are arranged in particular between the second surface 2 of the substrate 2 and the first surface 3a of the sensor film 3. A surface relief 5 is formed in the first surface 2a of the substrate 2, which follows the shape 6. The shape 6 is provided in particular by the sensor film 3 and the functional elements 33.

[0131] In particular, it is possible for the shape 6, in particular the contour and / or the relief, of the sensor film 3 to be modified by molding at least one surface relief, wherein the at least one surface relief is molded into one or more layers of the sensor film, in particular by means of one or more methods selected from: thermal replication, UV replication, laser ablation, punching, cutting, embossing, injection molding. The surface relief is preferably introduced into the first surface 3a and / or the second surface 3b of the sensor film 3.

[0132] Furthermore, it is possible for the shape, in particular the height relief and / or the contour, of the sensor film 3 to be modified by applying one or more elements, in particular by applying the functional elements 33, to the base film of the sensor film 3, which are applied in particular by means of one or more of the following methods: printing, in particular printing a lacquer and / or by means of 3D printing, laminating a single-layer or multi-layer film element, in particular a plastic label, applying a fabric, in particular glass fiber fabric, applying a fiber material, in particular an organic fiber material, back-injection molding, applying the one or more elements by means of a transfer method, in particular a hot or cold embossing method.

[0133] It is possible that the functional elements 33 are applied in particular to a first surface of a base film of the sensor film 3, wherein preferably the first surface of the base film faces the first surface 3a of the sensor film 3 and / or partially forms the first surface 3a of the sensor film.

[0134] Furthermore, it is possible for the functional elements 33 to be applied to one or more of the functional elements 33 applied to the first surface of the base film of the sensor film 3.

[0135] It is also possible for the functional elements 33 to be applied to the base film in the sensor region 30 of the sensor film 3 and to completely or partially overlap the sensor region 30, in particular projected onto the plane spanned by the first surface 3a of the at least one sensor film 3, in particular a flat or curved plane.

[0136] The Figure 8 shows the Figure 6 shown multilayer body in cross-section, except that the present multilayer body 1 has a curvature. Furthermore, the surface relief 5 formed in the first surface 2a of the substrate 2 has a curvature which in particular follows the curvature of the multilayer body 1.

[0137] It is possible that the layer sequence 4 underlying the multilayer body 1 preferably has a curvature with a minimum or maximum radius of curvature and / or with an average radius of curvature of not less than 1.5 mm, preferably not less than 1 mm, before thermoforming.

[0138] Furthermore, it is possible that the layer sequence 4 underlying the multilayer body 1 is modified during thermoforming such that the layer sequence 4 after thermoforming or the multilayer body 1 has a curvature with a minimum or maximum radius of curvature and / or with an average radius of curvature of not less than 1.5 mm, preferably not less than 1.0 mm.

[0139] Preferably, the layer sequence 4 and / or the multi-layer body 1 have different or identical curvatures in different directions.

[0140] The Figure 9 shows the Figure 7The multilayer body shown comprises the elements 33 in cross section, except that the present multilayer body 1 has a curvature. Furthermore, the surface relief 5 formed in the first surface 2a of the substrate 2 has a curvature that follows, in particular, the curvature of the multilayer body 1 and the shape 6 determined by the sensor film 3 and the functional elements 33.

[0141] The Figure 10 shows the Figure 9shown curved multilayer body in cross section, except that the present multilayer body 1 does not have functional elements 33 at the edges of the sensor film 3, but rather with different distances to the edges of the sensor film 3. Furthermore, the surface relief 5 formed in the first surface 2a of the substrate 2 has a curvature which in particular follows the curvature of the multilayer body 1 and the shape 6 determined by the sensor film 3 and the functional elements 33.

[0142] The Figure 11 shows the Figure 10shown curved multilayer body in cross-section, except that the present multilayer body 1 has functional elements 33 at the edges of the sensor film 3, has functional elements 33 at different distances from the edges of the sensor film 3 and has light guides 34 which are arranged in particular between the functional elements 33 on the first surface 3a of the sensor film 3. Furthermore, the surface relief 5 formed in the first surface 2a of the substrate 2 has a curvature which follows in particular the curvature of the multilayer body 1 and the shape 6 determined by the sensor film 3, the functional elements 33 and the light guide 34.

[0143] Preferably, one or more of the functional elements 33 are formed by an element which provides an electrical and / or optical function, in particular is formed by a light guide.

[0144] The Figure 12shows a sensor film 3 comprising a sensor region 30 and a connection region, which preferably ends in a contact region 37, as well as a first surface 3a and a second surface 3b in cross section. Furthermore, the sensor film 3 has a flat or planar shape 6. The sensor film 3 preferably comprises a base film.

[0145] It is possible that the sensor film 3 has the contact region 37 in particular for contacting, in particular for electrical contacting, one or more sensor elements arranged in the sensor region 30.

[0146] The Figure 13 shows the Figure 12 shown sensor film in cross section, except that the present sensor film 3 has a plastic label 32 lying in the sensor area 30 on the first surface 3a of the sensor film 3.

[0147] The Figure 14 shows the Figure 13shown sensor film comprising the plastic label 32 in cross section, except that the present sensor film 3 has functional elements 33 applied in the sensor area 30 on the surface of the plastic label 32 facing away from the sensor film 3.

[0148] In particular, the plastic label 32 and / or the functional elements 33 are applied as elements to the first surface of the base film of the sensor film 3, wherein the first surface of the base film faces the first surface 3a of the sensor film 3 and / or partially forms the first surface 3a of the sensor film 3.

[0149] Preferably, one or more plastic labels 32 and / or one or more functional elements 33 are applied to the plastic label 32 applied to the first surface of the base film of the sensor film 3 and / or to the functional elements 33 applied to the first surface of the base film of the sensor film.

[0150] It is possible for the plastic label 32 and / or the functional elements 33 to be applied in particular to the base film in the sensor region 30 of the sensor film 3 and to completely or partially overlap the sensor region 30, in particular projected onto the plane spanned by the first surface 3a of the at least one sensor film 3, in particular a flat or curved plane.

[0151] Furthermore, it is possible for the sensor film 3 to have the contact region 37, in particular for contacting one or more sensor elements arranged in the sensor region 30, and for the plastic label 32 and / or the functional elements 33 to be applied to the base film in the sensor region 30 of the sensor film 3 and preferably to completely or partially overlap the sensor region 30, in particular projected onto the plane spanned by the first surface 3a of the at least one sensor film 3, in particular a flat or curved plane, but not to overlap the contact region 37 of the sensor film 3.

[0152] The Figure 15 shows the Figure 14shown sensor film comprising the plastic label 32 and the functional elements 33 in cross section, except that the present sensor film 3 has a functional element 33 and a light guide 34 applied in the sensor area 30 on the surface of the plastic label 32 facing away from the sensor film 3.

[0153] The Figure 16 shows a substrate 2 comprising two decorative layers 41 in cross section, wherein the two decorative layers 41 are in particular each applied to the substrate 2 from the side of the first surface 2a of the substrate 2 and are applied to the substrate 2 from the side of the second surface 2b of the substrate 2.

[0154] The Figure 17 shows that in the Figure 16 shown substrate 2 comprising two decorative layers 41 and the Figure 13shown sensor film 3 comprising a plastic label 32 as a layer sequence 4 in cross section, wherein the side of the plastic label 32 facing away from the sensor film 3 rests in regions on the second surface 2b of the substrate 2.

[0155] The Figure 18 shows the Figure 17 shown layer sequence 4 after thermoforming as a multi-layer body 1 in cross section, wherein in the first surface 2a of the substrate 2 of the multi-layer body 1 a surface relief 5 is formed, which is determined in particular by the shape 6 of the surface of the plastic label 32 facing away from the sensor film 3.

[0156] The Figure 19 shows that in the Figure 14 shown substrate 2 comprising two decorative layers 41 and the Figure 141 shows the sensor film 3 shown, comprising a plastic label 32 and the functional elements 33, as a multilayer body 1 after thermoforming in cross-section, wherein the side of the plastic label 32 facing away from the sensor film 3 rests partially on the second surface 2b of the substrate 2. Furthermore, the surface relief 5 in the first surface 2a of the substrate 2 of the multilayer body 1 follows, in particular, the shape 6 determined by the sensor film 3, the plastic label 32, and the functional elements 33.

[0157] The Figure 20 shows the Figure 19shown multilayer body in cross section, except that the present multilayer body 1 or the substrate 2 comprising the two decorative layers 41 has two transparent regions 10. The functional elements are preferably designed as light guides 34. Viewed from the first surface 2a of the substrate 2, the light emitted by the light guides 43 can preferably be detected by a viewer through the transparent regions 10 of the substrate 2 comprising the two decorative layers 41. The transparent regions 10 are preferably integrated into the surface relief 5 in such a way that the light guides 34 can be detected in particular from the side of the first surface 2a of the substrate 2 of the multilayer body 1.

[0158] It is possible for the substrate 2 to have one or more transparent regions or the transparent regions 10, wherein in particular the transmittance of the substrate 2 between the first surface 2a of the substrate 2 and the second surface 2b of the substrate 2 in the one or more transparent regions or the transparent regions 10 in a wavelength range visible to the human eye is greater than 1%, preferably greater than 2%, more preferably greater than 4%, and / or less than 99%, preferably less than 95%, more preferably less than 92%.

[0159] Furthermore, it is also possible that the one or more sensor electrodes, in particular one or more active sensor regions of the one or more sensor electrodes, which are arranged in particular in the sensor film 3, have a transparency with a transmittance of more than 60%, in particular more than 80%, for the human eye and / or are each formed by a network of thin conductor tracks with a conductor track width between 3 µm and 60 µm, in particular 4 µm and 60 µm, particularly preferably between 4 µm and 50 µm.

[0160] It has proven advantageous for the touch functionality of the multilayer body 1 that the layer sequence 4 underlying the multilayer body has a capacitance of at most 200 pF, preferably at most 150 pF, more preferably at most 100 pF, at least in the sensor region 30.

[0161] Furthermore, it is advantageous that the surface relief 5 formed on the first surface 2a of the substrate 2 is preferably haptically and / or optically detectable and / or that the surface relief 5 formed on the first surface 2a of the substrate 2 is in particular haptically but not optically detectable or is optically but not haptically detectable or is haptically and not optically detectable or is optically and not haptically detectable.

[0162] Preferably, the surface relief 5 formed on the first surface of the substrate 2 is formed as Braille, in particular as one or more letters, one or more numbers, one or more words, and / or one or more sentences in Braille.

[0163] Furthermore, it is possible for the sensor film 3 to have one or more films and / or one or more layers in the sensor region 30, in particular in regions or over the entire surface, selected from: base film, plastic label 32, functional elements 33, in particular light guide 34, decorative layer 41, electrically conductive layer, in particular metallic layer, adhesive layer, adhesion promoter layer, wherein the one or more electrically conductive layers each have one or more sensor electrodes and / or one or more contact electrodes.

[0164] It is also possible for the sensor film 3 to have one or more sensor electrodes and / or one or more contact electrodes in the sensor region 30, wherein the sensor electrodes and / or the contact electrodes, in particular projected onto the plane spanned by the first surface 3a of the at least one sensor film 3, in particular a flat or curved plane, are arranged next to one another and / or do not overlap one another and / or, in particular when viewed parallel to a surface normal defined by the plane of the multi-layer body, one or more sensor electrodes of the one or more sensor electrodes overlap with one or more contact electrodes of the one or more contact electrodes.

[0165] Furthermore, it is possible that the surface relief 5, in particular projected onto the plane spanned by the first surface 3a of the sensor film 3, in particular a flat or curved plane, is composed at least partially of one or more straight, curved, circular-arc-shaped and / or circular elevations and / or depressions, in particular in the sensor region 30.

[0166] Furthermore, it is also possible that the surface relief 5, in particular projected onto the plane spanned by the first surface 3a of the sensor film 3, in particular a flat or curved plane, is formed at least partially with one or more linear, spiral and / or elliptical elevations and / or depressions, in particular in the sensor region 30.

[0167] Preferably, the surface relief 5, in particular in the sensor region 30, is formed such that preferably one or more elevations of the one or more elevations and / or one or more depressions of the one or more depressions, in particular in the sensor region 30, each have a constant or varying flank angle and / or a constant or varying width and / or a constant or varying height or depth and / or a constant or varying curvature.

[0168] In particular, the shape of one or more elevations of the one or more elevations and / or one or more depressions of the one or more depressions, in particular projected onto the plane spanned by the first surface 3a of the sensor film 3, in particular a flat or curved plane, preferably in the sensor region 30, is in each case selected or combined from: line, straight line, motif, image, triangle, wave, square, polygon, curved line, circle, oval, trapezoid, parallelogram, rhombus, cross, sickle, branch structure, star, ellipse, random pattern, pseudo-random pattern, wherein the one or more elevations and / or the one or more depressions in particular overlap and / or complement one another.

[0169] It is possible for one or more elevations of the one or more elevations and / or one or more depressions of the one or more depressions to be formed over the course, in particular in the plane spanned by the first surface 3a of the sensor film 3, in particular a flat or curved plane, of the respective elevations and / or depressions in such a way that one or more of the heights of the elevations and / or one or more depths of the depressions, in particular perpendicular to the plane spanned by the second surface 2b of the substrate 2, do not vary or at least do so in sections, wherein the variation is selected from: undulating, symmetrical, asymmetrical, periodic, aperiodic, discrete, continuous, stepped. List of reference symbols:

[0170] 1 Multilayer body 10 Transparent area 2 Substrate 2a First surface 2b Second surface 3 Sensor film 3a First surface 3b Second surface 30 Sensor area 30 Edge area 31 Base film 31a First surface 31b Second surface 32 Plastic label 33 Functional element 34 Light guide 35 Sensor element 36 Sensor electrodes 36 Contact electrodes 37 Contact area 4 Layer sequence 41 Decorative layer 42 Electrically conductive layers 50 a Elevation 50 b Depression 5 Surface relief 6 Shaping 7 Surface relief h Height difference x Variable y Variable

Claims

1. Method for producing a multi-layer body (1), wherein the method comprises the following steps: providing a single-layered or multi-layered substrate (2) with a first surface (2a) and a second surface (2b), providing one or more sensor films (3), which each comprise at least one sensor region (30) and have a first surface (3a) and a second surface (3b) facing away from the first surface (3a), applying the one or more sensor films (3) onto the second surface (2b) of the substrate (2) in such a way that the first surface (3a) of the respective sensor film lies at least in regions on the second surface (2b) of the substrate (2), thermoforming a layer sequence (4) comprising the substrate (2) and the one or more sensor films (3) applied to the second surface (2b) of the substrate (2) in such a way that a surface relief (5) is formed on the first surface (2a) of the substrate (2) during thermoforming, which surface relief is determined by the shaping (6), in particular contour and / or elevation relief, of one or more of the one or more sensor films (3), wherein the one or more sensor films (3) each have one or more capacitive and / or resistive sensor elements in the at least one sensor region (30), and wherein the one or more sensor films (3) each has at least one connection region and / or contact region (37) for contacting one or more of the sensor elements (35), characterised in that, when providing at least one sensor film (3) of the one or more sensor films (3), the elevation relief of the at least one sensor film is modified, wherein a substrate (2) is provided as a substrate (2), which, after thermoforming, has a layer thickness, in particular an average layer thickness, between 125 µm and 3500 µm, in particular between 400 µm and 1500 µm, preferably between 600 µm and 1100 µm, and wherein the surface relief (5) formed on the first surface (2a) of the substrate (2) has a maximum elevation difference and / or an average elevation difference between a local minimum of the surface relief (5) or a global minimum of the surface relief (5) and a local maximum of the surface relief (5) or a global maximum of the surface relief (5) which is less than 5000 µm, in particular less than 2000 µm, preferably less than 1000 µm.

2. Method according to claim 1, characterised in that, when providing at least one sensor film (3) of the one or more sensor films (3), the contour and the elevation relief of the at least one sensor film (3) is modified.

3. Method according to one of claims 1 or 2, characterised in that one or more sensor films of the one or more sensor films (3) are preferably provided as a transfer film, as a laminating film, as an in-mould film, as a label, as an in-mould label and / or as a sensor label.

4. Method according to one of the preceding claims, characterised in that the shaping (6), in particular the contour and / or the elevation relief, of the at least one sensor film (3) is modified by moulding at least one surface relief (7), wherein the at least one surface relief (7) is moulded into one or more layers of the sensor film (3), in particular by means of one or more methods, selected from: thermal replication, UV replication, laser ablation, punching or cutting, injection moulding.

5. Method according to one of the preceding claims, characterised in that the shaping, in particular the elevation relief and / or the contour, of the at least one sensor film (3) is modified by applying one or more elements to a base film (31) of the sensor film (3), which are applied in particular by means of one or more of the following methods: printing, in particular imprinting a varnish and / or by means of 3D printing, laminating one of a single- or multi-layered film element, in particular a plastic label, applying a fabric, in particular glass fibre fabric, applying a fibre material, in particular an organic fibre material, back injection moulding, applying the one or more elements by means of a transfer process, in particular a hot or cold stamping process, preferably, that one or more plastic labels (32) and / or one or more functional elements (33) are applied onto a first surface (31a) of a base film (31) of the sensor film (3) as one or more elements, wherein the first surface (31a) of the base film (31) faces the first surface (3a) of the sensor film (3) and / or partially forms the first surface (3a) of the sensor film (3), wherein it is preferably provided that one or more plastic labels (32) and / or one or more functional elements (33) are applied onto one or more of the one or more plastic labels (32) and / or functional elements (33) applied onto the first surface (31a) of the base film (31) of the sensor film (3), in particular, the one or more plastic labels (32) and / or functional elements (33) are applied onto the base film (31) in the sensor region (30) of the sensor film (3), and completely or partially overlap the sensor region (30), in particular projected onto the plane spanned by the first surface (3a) of the at least one sensor film (3).

6. Method according to one of the preceding claims, characterised in that a substrate (2) having a first melting temperature is provided as a substrate (2) and a sensor film (3) having a second melting temperature is provided as a sensor film (3), wherein in particular the first melting temperature is lower, preferably lower by a factor of 1 to 3, further preferably lower by a factor of 1.3 to 2.5, than the second melting temperature.

7. Method according to one of the preceding claims, characterised in that a substrate (2) having a first softening temperature is provided as a substrate (2) and a sensor film (3) having a second softening temperature is provided as a sensor film (3), wherein in particular the first softening temperature is lower, preferably lower by a factor of 1 to 3, further preferably lower by a factor of 1.3 to 2.8, than the second softening temperature.

8. Method according to one of the preceding claims, characterised in that the change in the height of the provided substrate with laminated sensor, preferably a substrate with a laminated sensor with a predetermined layer thickness, in particular has a functional correlation to the layer thickness of the applied sensor film due to the thermoforming, wherein this functional correlation is in particular a second-degree polynomial in the form y=a·x2 + b·x + c, preferably with the parameters a=0.0035; b=0.4832, c=38.19, and preferably the variables x = layer thickness of the applied sensor label, y = height, in particular a height h, of the moulding at the location of the sensor label in comparison to the rest of the substrate surface without a sensor label after the thermoforming.

9. Method according to one of the preceding claims, characterised in that a sensor film (3) is provided as a sensor film (3) which has a base film (31) and one or more electrically conductive layers (42) applied onto and / or introduced into the base film (31), in particular consisting of a metallic material.

10. Method according to claim 9, characterised in that the one or more electrically conductive layers (42) form one or more sensor electrodes (36) in the sensor region (30) to form one or more of the sensor elements (35), in particular to form one or more capacitive sensor elements and / or form one or more resistive sensor elements, and / or that the one or more electrically conductive layers (42) in the connection region and / or contact region (37) have one or more contact electrodes (36') for contacting the one or more sensor electrodes (36).

11. Multi-layer body (1) comprising a single-layered or multi-layered substrate (2) having a first surface (2a) and a second surface (2b) and one or more sensor films (3), which each comprise at least one sensor region (30) and have a first surface (3a) and a second surface (3b) facing away from the first surface (3a), manufactured by a method according to one of claims 1 to 10, wherein the one or more sensor films (3) are arranged on the second surface (2b) of the substrate (2), wherein the first surface (3a) of the respective sensor film (3) lies at least in regions on the second surface (2b) of the substrate (2), and wherein a surface relief (5) is moulded on the first surface (2a) of the substrate (2), which surface relief is determined by the shaping (6), in particular contour and / or elevation relief, of one or more sensor films of the one or more sensor films (3), wherein the one or more sensor films (3) each have one or more capacitive and / or resistive sensor elements in the at least one sensor region (30), and wherein the one or more sensor films (3) each have at least one connection region and / or contact region (37) for contacting one or more of the sensor elements (35), wherein a substrate (2) is provided as a substrate (2) which, after thermoforming, has a layer thickness, in particular an average layer thickness, of between 125 µm and 3500 µm, in particular between 400 µm and 1500 µm, preferably between 600 µm and 1100 µm, and wherein the surface relief (5) formed on the first surface (2a) of the substrate (2) has a maximum elevation difference and / or an average elevation difference between a local minimum of the surface relief (5) or a global minimum of the surface relief (5) and a local maximum of the surface relief (5) or a global maximum of the surface relief (5) which is less than 5000 µm, in particular less than 2000 µm, preferably less than 1000 µm.

12. Multi-layer body according to claim 11, characterised in that one or more sensor films of the one or more sensor films (3) are preferably formed as a transfer film, as a laminating film, as an in-mould film, as a label, as an in-mould label and / or as a sensor label.

13. Multi-layer body (1) according to claim 11 or 12, characterised in that the one or more sensor films (3) in the sensor region (30), in particular in regions or across the whole surface, have one or more films and / or one or more layers, selected from: a base film (31), a plastic label (32), functional elements (33), in particular light guides (34), a decorative layer (41), an electrically conductive layer (42), in particular a metallic layer, an adhesive layer, a bonding agent layer, wherein the one or more electrically conductive layers each have one or more sensor electrodes (36) and / or one or more contact electrodes (36').

14. Multi-layer body (1) according to one of claims 11 to 13, characterised in that the one or more sensor films (3) in the sensor region (30) have one or more sensor electrodes (36) and / or one or more contact electrodes (36'), wherein the sensor electrodes (36) and / or the contact electrodes (36'), in particular projected onto the plane spanned by the first surface (3a) of the at least one sensor film (3), are arranged next to one another and / or do not overlap and / or, in particular when viewed parallel to one of the surface normals defined by the plane of the multi-layer body, one or more sensor electrodes of the one or more sensor electrodes (36) overlap with one or more contact electrodes of the one or more contact electrodes (36').