Membrane and method for producing the same

Abstract

The invention relates to a film (1), a method for producing the film (1), and an electrical functional element. The film (1) comprises a carrier substrate (2), an adhesion promoter layer (4) for applying the film (1) to a target substrate (10), and at least one electrically conductive layer (3), wherein the at least one electrically conductive layer (3) forms an electrically functional structure in a functional region (21), wherein the at least one electrically conductive layer (3) forms at least one contact structure in at least one contact region (20) for contacting the electrically functional structure, and wherein the adhesion promoter layer (4) at least partially does not cover the at least one contact region (20) when viewed perpendicularly to a plane defined by the carrier substrate (2), or wherein the adhesion promoter layer (4) is applied over the entire surface when viewed perpendicularly to a plane defined by the carrier substrate (2).

Description

[0001] This application is a divisional application of an invention patent application with an application date of November 21, 2016, application number 201680081103.2, international application number PCT / EP2016 / 078349, and invention name “Membrane and method for manufacturing membrane”. Technical Field

[0002] The invention relates to a membrane, a method for producing a membrane, the use of a membrane for application to a target substrate and a method for producing an electrical functional element. Background Art

[0003] Combined input and output devices such as touch screens, also called sensor screens, have a variety of applications. Thus, by using a touch screen, it is possible, for example, to control a computer program by touching the touch screen. For this purpose, a touch sensor field that detects contact is usually arranged on a display element, such as a liquid crystal display. The touch sensor field thus makes it possible to control the image generated by the display element. Therefore, other input devices such as a computer mouse or keyboard are not required or are only required for special applications. Due to its usually smooth surface, the touch sensor field is less susceptible to dirt and is easier to clean than other input devices. In addition, it allows the user to perform intuitive operation. Therefore, touch sensors are used in a variety of ways, for example in mobile phones, especially smart phones, as well as PDAs, tablet computers, automatic teller machines, ticket machines, arcade machines and game consoles, and also in household appliances or motor vehicles.

[0004] In order to manufacture such a touch screen, the touch sensor is bonded to a target substrate, such as a display element, by means of a separate adhesive film. The adhesive film has a non-self-supporting adhesive layer here, which is arranged between two so-called lining layers. In order to apply the touch sensor, a lining layer of the adhesive film is removed in a first step and the adhesive layer is subsequently bonded to the touch sensor. In a second step, the remaining lining layer is removed and the touch sensor is bonded to the target substrate. Because the manufacturing process is usually performed manually, it is not always possible to ensure the same manufacturing quality. For example, the precise positioning of the touch sensor when applied to the target substrate is prone to error. The peeling of each working step, especially the lining layer, and the application of the adhesive layer to the touch sensor or the touch sensor to the target substrate without inclusions also require high time and manpower consumption. Especially in mass production, in order to realize a manufacturing process that is as uninterrupted as possible, providing various primary products also requires high logistics costs. Summary of the invention

[0005] The object of the present invention is now to provide a membrane which avoids the disadvantages of the prior art.

[0006] This object is achieved by a film having a carrier substrate, an adhesion promoter layer for applying the film to a target substrate, and at least one electrically conductive layer, wherein the at least one electrically conductive layer forms an electrically functional structure in a functional region, wherein the at least one electrically conductive layer forms at least one contact-making structure in at least one contact-making region for contact-making of the electrically functional structure, and when viewed perpendicularly to a plane defined by the carrier substrate, the adhesion promoter layer at least partially does not cover the at least one contact-making region, or when viewed perpendicularly to a plane defined by the carrier substrate, the adhesion promoter layer is applied over the entire surface, wherein:

[0007] a1) the at least one electrically conductive layer is arranged between the carrier matrix and the adhesion promoter layer, or b1) the adhesion promoter layer is arranged on the side of the carrier matrix facing away from the at least one electrically conductive layer, and

[0008] c1) An adhesion promoter layer is provided on the surface of the film.

[0009] The object is also achieved by a method for producing a membrane, in particular a membrane according to the invention, wherein the method comprises the following steps, which are carried out in particular in the following order:

[0010] a) providing a carrier matrix;

[0011] b) applying at least one electrically conductive layer to the carrier substrate, wherein the at least one electrically conductive layer forms an electrically functional structure in the functional region, wherein the at least one electrically conductive layer forms at least one contact structure in at least one contact region for contacting the electrically functional structure;

[0012] c) applying an adhesion promoter layer for applying the film to a target substrate in such a way that, when viewed perpendicularly to a plane defined by the carrier substrate, the adhesion promoter layer at least partially does not cover the at least one contact-making region, or, when viewed perpendicularly to a plane defined by the carrier substrate, the adhesion promoter layer is applied over the entire surface, wherein

[0013] a1) the at least one electrically conductive layer is arranged between the carrier matrix and the adhesion promoter layer, or b1) the adhesion promoter layer is arranged on the side of the carrier matrix facing away from the at least one electrically conductive layer, and

[0014] c1) An adhesion promoter layer is provided on the surface of the film.

[0015] The object is also achieved by a use of the film according to the invention, namely for application to a target substrate. The object is also achieved by a method for producing an electrical functional element, wherein the method comprises the following steps: a) providing the film according to the invention; b) applying the film to the target substrate. The object is also achieved by an electrical functional element having the film according to the invention.

[0016] It has been confirmed here that the film according to the present invention improves the manufacturing process of electrical functional elements, such as touch screens. In this way, the film according to the present invention enables the film to be applied directly to the target substrate without other intermediate steps and / or other intermediate products. This enables a faster manufacturing process and reduces the cost in manufacturing. Since the adhesion promoter layer does not cover the at least one contact-making area at least partially, it is ensured that the electrical functional structure can be reliably and firmly contacted after the film is applied to the target substrate. Because the contact-making area is not attached to the target substrate in the area without the adhesion promoter layer, the contact-making area is easy to access for contact-making. It is also possible to reduce waste compared to the case of using an adhesive film including a non-self-supporting adhesive layer arranged between two so-called lining layers, because for example, it is not necessary to perform the error-prone and complex adaptation of the adhesive film that has existed so far alone to the target substrate, nor is it necessary to perform the manual adaptation of the adhesive film to the touch sensor. Manufacturing costs can thus be reduced. The film according to the present invention also enables industrial mass production. In this way, for example, the film can be applied to the target substrate over its entire surface by means of a hot laminating machine. In hot lamination, pressure and heat are applied to individual, in particular loose layers of the stack in order to connect the individual layers of the stack inseparably to one another and thereby form a composite. In this case, pressure and / or heat are applied to the stack, for example, by means of a planar tool. Alternatively or additionally, rollers can also be provided as tools, for example, which can apply pressure and / or heat to the stack with line contact in the roller gap. This can further reduce time, labor and logistical costs and at the same time ensure that the same manufacturing quality is achieved. In this way, the present invention makes it possible to manufacture electrical functional elements, such as displays including touch sensors, at low cost and at the same time makes it possible to securely and reliably contact electrical functional structures, which, for example, provide a touch area function.

[0017] In this context, a region is understood to mean a defined surface of a layer or film, which is occupied by the layer or film when viewed perpendicularly to a plane defined by the carrier substrate. Thus, for example, the at least one electrically conductive layer has a functional region and at least one contacting region, wherein each of the regions occupies a defined surface when viewed perpendicularly to the plane defined by the carrier substrate.

[0018] It has proven to be feasible to arrange the at least one electrically conductive layer between the carrier matrix and the adhesion promoter layer.

[0019] The adhesion promoter layer can thus be arranged on the side of the at least one electrically conductive layer facing away from the carrier substrate. The adhesion promoter layer can thus be applied in step c) in such a way that the at least one electrically conductive layer is arranged between the carrier substrate and the adhesion promoter layer. Since the adhesion promoter layer is arranged on the surface of the film, the film can be applied directly to the target substrate, and it is also ensured that the electrical functional structures can be reliably contacted.

[0020] The adhesion promoter layer can also be arranged on the side of the carrier substrate facing away from the at least one electrically conductive layer. Thus, in step c), the adhesion promoter layer can be arranged on the side of the carrier substrate facing away from the at least one electrically conductive layer.

[0021] When viewed perpendicularly to the plane defined by the carrier substrate, the adhesion promoter layer is preferably applied over the entire surface. The adhesion promoter layer is thus advantageously arranged in the functional area and the contact-making area. In addition, the adhesion promoter layer can also be applied over the entire surface to the carrier substrate in such a way that no other layers are arranged between the carrier substrate and the adhesion promoter layer.

[0022] The adhesion promoter layer preferably covers the functional area at least in part. In step c), the adhesion promoter layer can be applied in such a way that the adhesion promoter layer covers the functional area at least in part. This ensures that the functional area adheres to the target substrate.

[0023] Adhesion here means that the film is attached to the target substrate in such a way that a predetermined minimum adhesion force is achieved, which allows the film to be reliably attached to the target substrate. The adhesion force here is at least so strong that the film will not be separated from the semi-finished product or finished product with the applied film and the target substrate in normal use. However, the adhesion force here does not have to be so strong that the film cannot be separated from the target substrate even when a large amount of force is consumed, for example when it is torn off. Such an adhesion force can thus be set so that the film can be separated from the target substrate mechanically without damaging the target substrate or the film.

[0024] The adhesion promoter layer advantageously covers at least 30%, preferably at least 50%, further preferably at least 70% of the functional area.

[0025] Furthermore, the adhesion promoter layer may not cover the at least one contact area over its entire surface. It is thus possible that, when viewed perpendicularly to a plane defined by the carrier substrate, the entire at least one contact area is not covered by the adhesion promoter layer. This makes it possible to reliably and securely contact an electrical functional structure that, for example, provides a touch field function.

[0026] Advantageously, the adhesion promoter layer does not cover a region adjoining the at least one contact-making region when viewed perpendicularly to a plane defined by the carrier substrate.

[0027] It is also advantageous if the region adjacent to the at least one contact region has a width of at least 0.2 mm, preferably at least 0.5 mm, further preferably at least 1 mm, and further preferably at least 2 mm. The width here refers to the distance between the interface formed by the at least one contact region and the region adjacent to the at least one contact region and the interface formed by the adhesion promoter layer and the region adjacent to the at least one contact region.

[0028] This makes it easier to make contact with the electrically functional structure, since the area in which the membrane is not attached to the target substrate is enlarged. Since this area is directly adjacent to the contact-making area, for example, the membrane can be lifted in the contact-making area during the contact-making process, thereby making the contact-making structure more accessible and thus further facilitating the contact-making. It is possible that the area adjacent to the at least one contact-making area is movable, thereby making the at least one contact-making area liftable.

[0029] According to another embodiment of the present invention, the adhesion promoter layer is a layer of a polymer and / or a copolymer, in particular containing polymethyl(meth)acrylate (PMMA), polyester, polyurethane (PU) or polyvinyl chloride (PVC).

[0030] Less preferably, the adhesion promoter layer protects a natural resin, preferably rosin, a phenolic resin, an isocyanate (NCO)-crosslinked binder, such as melamine-formaldehyde-condensation resin (MF), melamine-phenol-formaldehyde resin (MPF), melamine-polyester, melamine-urea-formaldehyde resin (UMF), poly(organo)siloxane or a radiation-curing binder.

[0031] The term "binding agent" refers here to a material through which solids, especially in fine dispersion, can be connected to one another or to a base. In this way, the binding agent can be added to the solids to be bonded in the form of a liquid.

[0032] The adhesion promoter layer advantageously has a layer thickness of between 0.1 μm and 50 μm, preferably between 0.25 μm and 25 μm, further preferably between 0.5 μm and 7 μm.

[0033] It is also advantageous if the adhesion promoter layer comprises one or more layers. It is thus possible that the adhesion promoter layer comprises two layers, in particular a first adhesion promoter layer and a second adhesion promoter layer. This allows the adhesion of the film to the target substrate to be optimized. In particular, the second adhesion promoter layer, which is arranged between the first adhesion promoter layer and the target substrate, can be coordinated, for example, with the material of the target substrate, while the first adhesion promoter layer can be coordinated with the material of the layer of the film adjoining the first adhesion promoter layer, for example a protective lacquer layer. Thus, by appropriately selecting the first and second adhesion promoter layers, the adhesion of the film to the target substrate can be optimized.

[0034] Advantageously, the adhesion promoter layer is made of such a material, which is highly transparent after the film is applied to the target substrate, and the adhesion promoter layer is especially made of such a material, which has a transmittance of more than 85%, preferably more than 90%, for the light in the wavelength range between 380nm and 780nm after the film is applied to the target substrate. Thus, for example, it can be achieved that the light in the wavelength range between 380nm and 780nm emitted by the target substrate will not be significantly weakened in its intensity due to the adhesion promoter layer. In addition, the visual information of the target substrate can be clearly seen through the film applied to the target substrate. Thus, for example, it can be achieved that the resolution and color reproduction of the display to which the film is applied are not changed for the observer.

[0035] The adhesion promoter layer can have a turbid visual appearance in a state not yet applied on the target substrate and is therefore not (yet) highly transparent. The turbid appearance may be produced, for example, due to the difference in the refractive index of the adhesion promoter layer and the surrounding air and / or due to the surface roughness of the adhesion promoter layer, especially the surface roughness on the side of the adhesion promoter layer away from the at least one conductive layer. The surface roughness may scatter the incident light and thus produce a turbid visual effect. Such surface roughness may be produced in particular due to the coating method used when applying the adhesion promoter layer. For example, the surface roughness can be formed by the printing pattern of the gravure anilox roller or screen printing tool. In contrast, the adhesion promoter layer is highly transparent after the film is applied to the target substrate, because the adhesion promoter layer is melted and / or becomes flattened by pressure, especially by means of hot lamination, so that the surface roughness of the adhesion promoter layer no longer appears as interference in the appearance. The refractive index difference between the adhesion promoter layer and the material adjacent to it can also be eliminated according to the refractive index of the target substrate. As a result, the optical boundary surface between the adhesion promoter layer and the target substrate is no longer visible.

[0036] Transparency here refers to the property of a substance that allows light in the wavelength range visible to the human eye, in particular in the wavelength range between 380 nm and 780 nm to pass through. The term "highly transparent" therefore describes the property of a substance that allows light in the wavelength range visible to the human eye, in particular in the wavelength range between 380 nm and 780 nm to pass through almost without attenuation and essentially without hindrance. A highly transparent layer therefore has essentially no perceptible light absorption for a human observer, so that a reduction in light intensity when light passes through the layer is barely perceptible to a human observer.

[0037] Turbidity refers here to the property of a substance that light in the wavelength range visible to the human eye, in particular in the wavelength range between 380 nm and 780 nm, cannot penetrate the substance unimpeded. A turbid layer prevents light from penetrating the layer unimpeded, for example, by scattering properties. Light can also be absorbed and / or reflected in a turbid layer. A turbid layer can, for example, produce a milky visual effect for a human observer, so that other layers arranged below the turbid layer are perceived as, for example, smeared and / or obscured.

[0038] In addition, it is advantageous that the adhesion promoter layer is made of such a material, which is clear after the film is applied to the target substrate, and in particular, the adhesion promoter layer is made of such a material, which makes less than 8%, preferably less than 4%, of the light in the wavelength range between 380nm and 780nm turn due to scattering after the film is applied to the target substrate. Thus, it can be achieved, for example, that the image produced by the target substrate, such as a display, will not be substantially affected by the film applied to the target substrate for a human observer. Like this, due to the small scattering of the adhesion promoter layer and the material of the adhesion promoter layer itself, it can be guaranteed that if the film is applied to the display, the image produced by the display will not be felt as blurred or smeared for a human observer. Thus, especially in high-resolution displays with a pixel density of more than 200ppi (ppi=Pixelper Inch, pixels per inch), it is possible to achieve an outstanding and faithful look and feel of the image produced by the display through the film.

[0039] As explained above, in the state before application to the target substrate, the adhesion promoter layer can have light scattering properties due to the surface roughness of the adhesion promoter layer and thus have a cloudy visual appearance. The adhesion promoter layer is clear in particular when the film has been applied to the target substrate and the adhesion promoter layer is melted and / or smoothed, for example, by heat and / or pressure supplied by hot lamination, so that the surface roughness of the adhesion promoter layer is no longer disruptive in the visual effect. That is to say, due to physical and / or chemical changes in the adhesion promoter layer during or after application of the film to the target substrate, the adhesion promoter layer becomes highly transparent and / or clear.

[0040] The adhesion promoter layer can be formed by a hot melt adhesive, a cold adhesive or a radiation-curable adhesive, in particular an adhesive that can be cured by means of electromagnetic radiation and / or electron radiation.

[0041] In addition, the bonding agent layer is designed in a pattern, especially in a rectangle, a rounded rectangle or a themed shape, so that the pattern of the bonding agent layer designed in a pattern can be adapted to the structure of the target substrate.

[0042] The adhesion promoter layer can also be applied in a grid, in particular a one-dimensional or two-dimensional grid. In this way, the adhesion promoter layer can be applied in a dot grid or a line grid. During the application of the film to the target substrate, the grid formed by the adhesion promoter layer is flattened so that the transparency of the film is not negatively affected by the adhesion promoter layer applied in a grid.

[0043] The film advantageously has a transmittance of more than 75%, preferably more than 80%, further preferably more than 85%, and still further preferably more than 90% for light in the wavelength range between 380 nm and 780 nm, at least in the functional region of the at least one electrically conductive layer after being applied to the target substrate.

[0044] Here, the transmittance describes the permeability of the film for light in the wavelength range between 380nm and 780nm. The light incident on the film is partially reflected at the air-film interface and at the interfaces of the film layers. In addition, the light incident on the film is partially absorbed when crossing the film. The remaining portion of the light is emitted through the film and emitted again on the opposite side of the film. In order to determine the transmittance τ, the quotient of the light intensity I behind the film and the light intensity I0 in front of the film is calculated. The transmittance τ is a measure of the intensity that describes the "allowed to pass through" and has a value between 0 and 1. The transmittance is usually related to the wavelength of the incident light. Therefore, in addition to the transmittance value, the wavelength range is also given.

[0045] As explained above, the adhesion promoter layer can have a cloudy visual appearance before the film is applied to the target substrate, for example due to surface roughness. In particular, the surface roughness is leveled during the application process, so that the adhesion promoter layer is highly transparent and / or clear after application to the target substrate, so that the cloudy visual appearance of the adhesion promoter layer disappears and the film as a whole has a transmittance of more than 75%, preferably more than 80%, more preferably more than 85%, and even more preferably more than 90% for light in the wavelength range between 380 nm and 780 nm, at least in the functional area of ​​the at least one electrically conductive layer. As will be explained later, it is advantageous to apply the film to a target substrate with a known transmittance and then determine the total transmittance of the electrical functional element formed by the target substrate and the film.

[0046] According to another embodiment of the invention, the film has a release layer, wherein the release layer at least partially covers the at least one contact-making area when viewed perpendicularly to the plane defined by the carrier substrate. It is possible that the method further comprises the following step: e) applying the release layer in such a way that the release layer at least partially covers the at least one contact-making area when viewed perpendicularly to the plane defined by the carrier substrate. In this way, the release layer prevents adhesion of the at least one contact-making area.

[0047] Furthermore, it is advantageous if the carrier substrate and / or the at least one electrically conductive layer and / or the release layer and / or the protective lacquer layer are embodied in a transparent manner.

[0048] The release layer can also cover the at least one contact-making region over its entire surface.

[0049] Furthermore, the release layer can cover a region adjoining the at least one contact-making region.

[0050] Furthermore, the release layer can ensure that the film does not adhere to the target substrate in the region with the release layer. Thus, the release layer can prevent the at least one contact region from adhering to the target substrate, in particular preventing the at least one contact region from adhering to the target substrate due to hot lamination of the film onto the target substrate.

[0051] The release layer is preferably made of wax, polyethylene (PE), polypropylene (PP), cellulose derivatives or poly(organo)siloxanes.

[0052] The aforementioned wax may be a natural wax, a synthetic wax or a combination thereof. The aforementioned wax may be, for example, palm wax. The aforementioned cellulose derivative may be, for example, cellulose acetate (CA), cellulose nitrate (CN), cellulose acetate butyrate (CAB) or a mixture thereof. The aforementioned poly(organic)siloxane may be, for example, a silicone binder, a polysiloxane binder or a mixture thereof.

[0053] Less preferably, the release layer comprises a natural resin, preferably rosin, a phenolic resin, a halogen-containing homopolymer, such as polyvinyl chloride (PVC), polyvinyl fluoride (PVF), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF) or polyvinylidene chloride (PVDC), a polyester, such as polybutylene terephthalate (PBT), polyethylene terephthalate (PCT), polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polycarbonate (PC), polyester carbonate (PEC), polyacrylate (PAC) or unsaturated polyester resins (UP), polymer carbonates, such as polymethyl (meth) acrylate (PMMA), isocyanate (NCO) crosslinked binders, such as melamine-formaldehyde-condensation resins (MF), melamine-phenol-formaldehyde-resins (MPF), melamine-polyesters, melamine-urea-formaldehyde-resins (UMF), polyolefins other than PP or PE, such as polymethylpentene (PMP), polyisobutylene (PIB) or polybutylene (PB), copolymers made of PVC, PMMA, PU, ​​poly(organo)siloxanes and polyolefins other than PP or PE.

[0054] To a lesser extent, the release layer also contains a radiation-hardening binder.

[0055] The release layer preferably has a layer thickness between 0.1 μm and 10 μm, preferably between 0.1 μm and 5 μm. This small layer thickness is advantageous, since electrical contact can be made to the at least one contact area covered by the release layer, in particular by means of adapter elements and / or connecting elements and / or contact elements, for example by means of contact springs, ZIF plugs (ZIF=Zero Insertion Force), crimp contacts, flexible crimp contacts, ACF bonds (Anisotrope Conductive Film) or conductive rubber connectors (ZEBRA). In this case, the release layer is advantageously partially penetrated in the electrical contact structure, in particular by the adapter element and / or connecting element and / or contact element, so that the release layer no longer locally has an effect that hinders electrical contact, in particular electrical insulation. It is advantageous here that when contact is made, in particular by means of mechanical and physical forces of the adapter element and / or the connecting element and / or the contact element, the electrically insulating release layer is destroyed in such a way that conductivity is generated in particular between the at least one contact area and the adapter element and / or the connecting element and / or the contact element. This is achieved, for example, by means of a contact spring or by shrinkage. In addition, the ZIF contact also mechanically produces a "cutting effect", thereby also enabling electrical contact to be made to the at least one contact area covered by the release layer. In the ACF bonding, the metal pigments in the adhesive layer can penetrate the release layer when the film is pressed, so that electrical contact can also be achieved using the ACF bonding.

[0056] Furthermore, it is also possible that the electrical contacting does not necessarily have to take place by means of an electrical connection between the at least one contacting region and the adapter element and / or the connecting element and / or the contact element and / or the contact layer, in particular the target substrate. Thus, the electrical contacting can also be achieved by means of a capacitive coupling between two contact surfaces, for example the at least one contacting region and the target contacting region, in particular the contact layer of the target substrate, wherein at least one insulating layer is provided between the contact surfaces.

[0057] According to another embodiment of the invention, the film has a protective lacquer layer.

[0058] Advantageously, the protective lacquer layer at least partially covers the at least one electrically conductive layer when viewed perpendicularly to the plane defined by the carrier substrate. It is also advantageous if the following step is carried out between step b) and step c): - the protective lacquer layer is applied in particular in such a way that the protective lacquer layer at least partially covers the at least one electrically conductive layer when viewed perpendicularly to the plane defined by the carrier substrate. In this way, the protective lacquer layer can protect the at least one electrically conductive layer from mechanical, physical and / or chemical environmental influences.

[0059] When viewed perpendicularly to a plane defined by the carrier substrate, the protective lacquer layer covers the at least one electrically conductive layer over the entire surface in the functional region.

[0060] The film may also have one or more protective lacquer layers.

[0061] In particular, the protective lacquer layer protects the other layers of the film against mechanical, physical and / or chemical environmental influences or the influence of other process steps, and the protective lacquer layer forms the outermost layer of the film or the semi-finished product or finished product, in particular the electrical functional element, to which the film is applied.

[0062] Advantageously, the protective lacquer layer has a layer thickness of between 0.1 μm and 50 μm, preferably between 0.25 μm and 25 μm, further preferably between 0.5 μm and 15 μm.

[0063] The protective lacquer layer is preferably a transparent protective lacquer layer, in particular a protective lacquer layer made of PMMA, polyester, PU or PVC.

[0064] To a lesser extent, the protective lacquer layer protects natural resins, preferably rosin, phenolic resins, isocyanate (NCO)-crosslinked binders, such as MF, MPF, melamine polyester, UMF, polyolefins other than PP or PE, such as PMP, PIB or PB.

[0065] It is also advantageous if the protective lacquer layer is arranged between the at least one conductive layer and the adhesion promoter layer. The protective lacquer layer can also be applied in such a way that the protective lacquer layer is arranged between the at least one conductive layer and the adhesion promoter layer. In this way, the protective lacquer layer can be arranged on the side of the at least one conductive layer facing away from the carrier substrate.

[0066] Furthermore, the membrane may have a construction in the following order:

[0067] -Carrier matrix

[0068] - at least one conductive layer

[0069] - Protective paint

[0070] - Adhesion promoter layer.

[0071] Furthermore, a protective lacquer layer can be arranged between the at least one electrically conductive layer and the carrier substrate. In this case, the electrically conductive layer is embedded and protected between the protective lacquer layer and the adhesion promoter layer. The protective lacquer layer and the adhesion promoter layer are preferably made of lacquers with similar physical properties, in particular regarding mechanical deformability and stretchability. This makes it possible that the embedded electrically conductive layer is not damaged, for example torn, in the event of a strong deformation of the film, so that the electrical functionality is preserved. Furthermore, by embedding the electrically conductive layer as described above, delamination of the layers is also prevented.

[0072] The film can also have a primer layer, in particular a vapor-depositable primer layer for metallization. The primer layer is advantageously arranged between the protective lacquer layer and the at least one electrically conductive layer.

[0073] The primer layer is advantageously a layer of a polymer and / or a copolymer, in particular comprising polymethyl(meth)acrylate (PMMA), polyester, polyurethane (PU) or polyvinyl chloride (PVC).

[0074] Less preferably, the primer layer comprises a natural resin, preferably rosin, a phenolic resin, an isocyanate (NCO)-crosslinked binder, for example melamine-formaldehyde-condensation resin (MF), melamine-phenol-formaldehyde resin (MPF), melamine-polyester, melamine-urea-formaldehyde resin (UMF), poly(organo)siloxane or a radiation-curing binder.

[0075] The primer layer preferably has a layer thickness of between 0.1 μm and 5 μm, preferably between 0.1 μm and 2 μm.

[0076] Furthermore, the membrane may have a construction in the following order:

[0077] -Carrier matrix

[0078] - Protective paint

[0079] - Primer layer

[0080] - at least one conductive layer

[0081] - Adhesion promoter layer.

[0082] It is furthermore advantageous if the film is a transfer film.

[0083] The transfer film advantageously comprises a carrier layer, in particular a carrier substrate, and a transfer layer which can be detached from the carrier layer, in particular the carrier substrate.

[0084] A separating layer is advantageously arranged between the carrier layer, in particular the carrier substrate, and the transfer layer, which separating layer makes it possible to peel the transfer layer off the carrier layer, in particular the carrier substrate.

[0085] In this way, only the transfer layer can be applied to the target substrate, in particular by means of hot embossing.

[0086] However, it is also possible not to remove the carrier layer, in particular the carrier matrix, after application to the target substrate, so that the carrier layer, in particular the carrier matrix, also remains on the target substrate.

[0087] Furthermore, the film can have a separating layer. It is possible that the separating layer is a one-layer or multi-layer separating layer. Preferably, the separating layer is arranged between the carrier substrate and the protective lacquer layer. This makes it possible, for example, to peel off the carrier substrate after the film has been applied to the target substrate. This makes it possible to achieve a better deformability and / or stretchability of the applied film, since the thicker and less deformable and / or less stretchable carrier substrate has been removed. The protective lacquer layer assumes the function of a protective film.

[0088] The separating layer is preferably a wax layer and / or a polymer layer such as a lacquer crosslinked with acrylates and / or melamine formaldehyde resins. The separating layer preferably has a layer thickness of less than 1 μm.

[0089] Advantageously, it can be provided that the adhesion between the carrier substrate and the protective lacquer layer is 20% to 80%, preferably 30% to 70%, smaller than the adhesion between the protective lacquer layer and the primer layer and / or the at least one conductive layer and / or the adhesion promoter layer due to the separating layer arranged between the carrier substrate and the protective lacquer layer.

[0090] Like this, it is possible that the adhesion between the carrier substrate and the protective lacquer layer is 20% to 80% less, preferably 30% to 70% less, than the adhesion between the layers of the transfer layer due to the separation layer arranged between the carrier substrate and the protective lacquer layer, and the layers of the transfer layer are especially selected from the following group: protective lacquer layer, primer layer, at least one conductive layer, one or more decorative layers, adhesion promoter layer, intermediate adhesion layer, dielectric layer, darkening layer and contact strengthening layer. The adhesion is determined using the tensile testing machine Zwick Z005 of the German company Zwick GmbH & Co. KG, Ulm. For this purpose, the transfer film is flatly bonded to the support below. Then the layer to be peeled off is peeled off at right angles by tensile testing. The peeling force is determined by a dynamometer.

[0091] Thus, the membrane may have a construction in the following order:

[0092] -Carrier matrix

[0093] -Separation layer

[0094] - Protective paint

[0095] - Primer layer

[0096] - at least one conductive layer

[0097] - Adhesion promoter layer.

[0098] In the embodiment variant of the film as a transfer film, since the adhesion promoter layer does not cover the at least one contacting region, the electrically functional structure can also be contacted after the film has been applied to the target substrate, so that an electrical connection can be established, for example, by means of the contacting method described above. In addition, the optional separating layer makes it possible to at least partially peel off the carrier substrate, thereby further improving the subsequent contacting possibilities, since the film in this embodiment variant is not always bonded to the edge of the carrier substrate.

[0099] Furthermore, reinforcing elements can be applied, in particular after removal of the carrier matrix, in order to increase the mechanical stability of the applied transfer layer.

[0100] According to a further embodiment variant, the target substrate has a contact layer, in particular the at least one contact region for an electrical contact-making film.

[0101] The contact layer is preferably applied directly to the target substrate.

[0102] Furthermore, the contact layer can have at least one connecting element.

[0103] Furthermore, the contact layer can also have at least one adapter element and / or contact element.

[0104] This means that the target substrate preferably already has at least one connecting element and / or adapter element and / or contact element, in particular the at least one contact-making region for an electrical contact-making foil.

[0105] The contact layer is advantageously arranged in at least one target contact area of ​​the target substrate. Preferably, the at least one target contact area of ​​the target substrate forms a corresponding part of the at least one contact area of ​​the film. It is advantageous that the at least one target contact area of ​​the target substrate and the at least one contact area of ​​the film are preferably congruently overlapped after the film is applied to the target substrate, and the at least one target contact area of ​​the target substrate and the at least one contact area of ​​the film overlap in particular at least partially after the film is applied.

[0106] In addition, the target substrate may have at least one third conductive layer. Preferably, the at least one third conductive layer has a plurality of conductor tracks. Thus, the at least one third conductive layer may have a conductive structure, in particular conductor tracks, which are preferably arranged in a grid. The grid may be regular or irregular. The grid may in particular be composed of grid elements, such as line and / or surface elements.

[0107] Furthermore, the at least one third electrically conductive layer may also include further electrical components.

[0108] The at least one third electrically conductive layer of the target substrate is advantageously electrically connected to the at least one contact layer.

[0109] Thus, the target substrate can be equipped with conductor tracks and / or other electrical components, for example. These conductor tracks can then advantageously be electrically connected to other electrical components in a known manner by means of plug contacts or other known contact-making methods. Preferably, this can be done by means of laser direct structuring (LDS) or by means of printed contacts, in particular by means of screen printing contacts, or also by means of contact layers, for example, applied by means of lamination and / or hot or cold embossing. Thus, the target substrate can be, for example, a circuit board.

[0110] This makes it possible to electrically connect the at least one third conductive layer of the target substrate to the functional region of the conductive layer of the membrane via the contact region of the membrane by means of the contact layer. That is, the contact layer on the target substrate forms corresponding contacts with the contact region of the membrane.

[0111] Furthermore, it is advantageous if the contact layer, in particular the at least one connecting element and / or the adapter element and / or the contact element and / or the at least one third electrically conductive layer is produced and / or applied by means of laser direct structuring (LDS) and / or by printing, in particular by means of screen printing.

[0112] Furthermore, it is also possible for the contact layer, in particular the at least one connecting element and / or adapter element and / or contact element to be applied by means of lamination and / or hot or cold embossing.

[0113] It is also possible that the contact layer, in particular the at least one connecting element and / or adapter element and / or contact element, is formed on a target substrate made of an electrically conductive paste, in particular a carbon paste, which contains silver (Ag), gold (Au), aluminum (Al), copper (Cu), chromium (Cr) and / or other electrically conductive metals. In addition, the electrically conductive paste, in particular the carbon paste, can have a binder, which in particular has rosin and / or phenolic resins, polymers and copolymers. The binder of the electrically conductive paste, in particular the carbon paste, is a natural resin, preferably rosin, phenolic resin, polymers and copolymers, which are composed of PVC, PMMA, PU, ​​polyester, isocyanate (NCO) crosslinked binders, such as MF, MPF, melamine polyester, UMF. Less preferred are binders of the electrically conductive paste containing poly(organic)siloxanes and copolymers and / or radiation-cured binders.

[0114] Furthermore, the film can be printed with adhesive lacquer completely or partially in the at least one contact-making region in a pattern, for example in a grid. Thus, the film can have adhesive lacquer in the at least one contact-making region.

[0115] Alternatively, it is also possible for the film to have no adhesive lacquer in the at least one contact-making region or to completely omit adhesive lacquer in places in the region of the contacts.

[0116] Therefore, preferably, when the film is applied to the target substrate provided with the contact layer, an electrical (pressure) contact between the film and the target substrate is produced (by heat and pressure), in particular in the at least one contact area and / or the target contact area. Here, the electrical (pressure) contact can be permanently effected by gluing, in particular by an adhesive lacquer.

[0117] Furthermore, an ACF bonding tape can be introduced between the at least one contact-making area of ​​the film and the at least one target contact-making area of ​​the target substrate. This can further improve the electrical connection in the contact-making area. It is advantageous here that the application process (heat and pressure) also corresponds as far as possible to a conventional ACF bonding process.

[0118] In addition advantageously, the contact layer of the target matrix is ​​designed to, so that two or more films can be applied to the target matrix. Like this, the contact layer of the target matrix can have a connecting element and / or an adapter element and / or a contact element, to connect at least two films for electrical contact.

[0119] In this way, the target substrate can also have a contact layer for contacting the first film in a first target contacting region and a contact layer for contacting the second film in a second target contacting region.

[0120] Advantageously, the target substrate to which the at least two films are to be applied already has a contact layer which is designed such that a two-layer sensor can be applied which comprises a film for the x-layer and a film for the y-layer.

[0121] In this way, the electrical contacts and contact leads for the double-layer sensor including the x-layer and the y-layer can also be arranged as described above on the target substrate to which the at least two films are to be applied. Preferably, the x-layer and the y-layer are each formed by a film according to the invention. First, preferably, the first sensor layer, for example the x-layer, is applied to the target substrate with the aid of the film according to the invention and electrical contact is established. Advantageously, the first sensor layer is applied to the target substrate with an exact fit relative to the contact layer, in particular relative to the at least one connecting element and / or adapter element and / or contact element of the target substrate, for in particular electrical contacting the first sensor layer.

[0122] It is thus possible that in a first step the first film is applied to the target substrate in such a way that the at least one contact-making region of the first film overlaps at least in places with a target contact-making region of the contact layer for contacting the first film.

[0123] Preferably, in a separate step, a second sensor layer, for example a y-layer, is then applied to the target substrate in a precise fit relative to the first sensor layer or relative to the contact layer, in particular the at least one connecting element and / or adapter element and / or contact element of the target substrate, by means of the film according to the invention, in particular for electrical contacting of the second sensor layer. It is possible here to dispense with bonding between the sensor layers, for example by means of OCA. The fit accuracy, that is to say the position accuracy of the second sensor layer relative to the first sensor layer, is preferably ±350 μm, more preferably ±150 μm in the x-direction and the y-direction, in order to achieve the desired function of the sensor.

[0124] It is thus possible that in a second step the second film is applied to the target substrate in such a way that the at least one contact-making region of the second film at least partially overlaps the target contact-making region of the contact layer for contacting the second film.

[0125] Preferred embodiments of the at least one contact region and / or the at least one contact structure are mainly described below.

[0126] The at least one contact-making structure for contacting electrical functional structures is preferably an electrical terminal, in particular a plug.

[0127] The at least one electrically conductive layer advantageously has a contact strengthening layer.

[0128] Furthermore, it is advantageous if the at least one electrically conductive layer comprises, at least in places in the at least one contact-making region, a contact strengthening layer, wherein the contact strengthening layer protects the at least one contact-making region against mechanical, physical and / or chemical environmental influences.

[0129] In this way, the following steps can be implemented between step b) and step c): - applying the contact strengthening layer (7) in such a way that the at least one conductive layer (3) has the contact strengthening layer (7), in particular the at least one conductive layer (3) has the contact strengthening layer (7) at least partially in the at least one contact connection area (20).

[0130] The contact strengthening layer improves the durability of the at least one contact region because the contact region is protected by the contact strengthening layer, for example, against corrosion or scratches. In addition, the mechanical stability of the contact region, in particular the bending stability and / or flexural stability, can also be improved.

[0131] Furthermore, the contact reinforcing layer can cover the at least one contact-making region over the entire surface.

[0132] The at least one contact region may also have one or more contact regions separated from each other. Separation here means that the contact regions are spaced apart from each other, in particular the contact regions are at least 0.1 mm, preferably at least 0.2 mm, further preferably at least 0.5 mm apart from each other.

[0133] Furthermore, it is advantageous if the contact strengthening layer has a layer thickness of between 0.1 μm and 100 μm, preferably between 0.25 μm and 25 μm, further preferably between 0.5 μm and 10 μm.

[0134] The contact reinforcement layer can be formed by an electrically conductive paste, in particular a carbon paste, which contains silver (Ag), gold (Au), aluminum (Al), copper (Cu), chromium (Cr) and / or other electrically conductive metals. It is also possible that the electrically conductive paste, in particular a carbon paste, has a binder, in particular rosin and / or phenolic resin, polymers and copolymers.

[0135] Binders for conductive pastes, in particular carbon pastes, are natural resins, preferably rosin, phenolic resins, polymers and copolymers consisting of PVC, PMMA, PU, ​​polyester, isocyanate (NCO)-crosslinked binders, such as MF, MPF, melamine polyester, UMF.

[0136] To a lesser extent, the conductive paste has a binder of poly(organo)siloxanes and copolymers and / or a radiation-curing binder.

[0137] Advantageously, the adhesion promoter layer, the protective lacquer layer, the release layer and / or the contact reinforcing layer are applied by means of gravure printing, screen printing, relief printing or casting technology.

[0138] The preferred design of the at least one conductive layer and / or the electrical functional structure is mainly described below:

[0139] According to another embodiment of the invention, the electrically functional structure forms a touch sensor area, in particular a capacitive sensor area, which provides a touch area function. The electrically functional structure can also form a resistive or inductive sensor area.

[0140] The touch sensor area is here understood to be a contact-sensitive sensor which enables the control of an electrical functional element, such as a PDA. The touch sensor area is also understood to be a multi-touch sensor area which can process multiple simultaneous contacts, for example for enlarging and rotating an image which is displayed on a display, in particular arranged below the touch sensor area.

[0141] In a preferred embodiment, it is provided that the film has at least two electrically conductive layers, in particular a first electrically conductive layer and a second electrically conductive layer.

[0142] The at least two electrically conductive layers are advantageously arranged at least partially overlapping each other when viewed perpendicularly to a plane defined by the carrier substrate.

[0143] In this way, in particular, multilayer touch sensors can be produced, which can also process multiple simultaneous contacts, for example for enlarging and rotating images. For example, the second conductive layer can be provided on a second carrier film, which is applied to the first conductive layer, in particular bonded, in particular by means of an adhesion promoter layer and / or an intermediate adhesive layer and / or by means of a primer layer and / or an adhesive layer. The primer layer and / or the adhesive layer can be formed by a hot melt adhesive, a cold adhesive or a radiation-curable adhesive, in particular an adhesive that can be cured by means of electromagnetic radiation and / or electron radiation.

[0144] When applying the second conductive layer to the first conductive layer, it is expedient to achieve the relative positioning of the two conductive layers in a precise manner in coordination with each other, in particular with a tolerance of less than 0.25 mm, preferably with a tolerance of less than 0.1 mm, so as to produce an undisturbed touch function. It is thus possible to arrange the at least two conductive layers in a precise manner in coordination with each other, in particular with a tolerance of less than 0.25 mm, preferably less than 0.1 mm relative to each other. The conductive layers here in particular have conductive structures, in particular conductor tracks, which are preferably arranged in a grid. The grid can be regular or irregular. The grid can in particular consist of grid elements, such as line and / or surface elements. Here, the grid elements can form so-called sensor rows.

[0145] According to another embodiment of the present invention, the at least one conductive layer and / or the two conductive layers have a plurality of conductor tracks.

[0146] Conductor tracks here preferably refer to the structured conductive layer and the conductive areas of the at least one conductive layer and / or the two conductive layers. The conductor tracks are applied in particular in such a way that sufficient transparency for the human eye is retained, that is to say the conductor tracks are designed so that they are not perceptible to a human observer, since they are below the resolution capability of the human eye. Despite the use of narrow conductor tracks, sufficient conductivity is achieved, in particular a conductivity comparable to that of a layer of indium tin oxide (ITO). Preferably, the at least one conductive layer, in particular the conductor tracks, occupies less than 30% of the carrier substrate, preferably less than 20%, further preferably less than 10%, and further preferably less than 5%.

[0147] The conductor tracks are advantageously spaced apart from one another, in particular the conductor tracks have a width of between 0.2 μm and 20 μm, preferably between 4 μm and 15 μm, and are at a distance from one another of more than 10 μm, preferably more than 20 μm, so that the conductor tracks are below the resolution capability of the human eye.

[0148] Advantageously, the conductor lines of the first conductive layer and the second conductive layer are respectively arranged according to a wire grid, wherein in particular the wire grids are rotated 90° relative to each other. Thus, the first conductive layer and the second layer each have a wire grid consisting of conductor lines spaced apart from each other. The first conductive layer and the second layer are preferably arranged one on top of the other in such a way that the two wire grids are arranged at a right angle, i.e. 90°, relative to each other. Preferably, electrical leads and / or contact connection elements are arranged in the edge regions of the two wire grids. Preferably, these edge regions are precisely arranged relative to each other, in particular in the direction of the coordinate axes x and y, with a tolerance fit of less than 0.25 mm, preferably less than 0.1 mm, wherein the plane defined by the coordinate axes x and y is parallel to the plane defined by the carrier substrate.

[0149] In another preferred embodiment, the conductor paths of the first conductive layer and the second conductive layer are structured, in particular structured in such a way that the conductor paths of the first conductive layer and the second conductive layer are composed of a plurality of surface elements, preferably rhombus or oblique square surface elements. For example, it is possible that the first conductive layer and the second layer each have a so-called diamond structure. The diamond structure is formed along a linear conductor path by a plurality of, in particular, rhombus-shaped surface elements. In this case, the first conductive layer and the second layer each have a plurality of diamond structures spaced apart from each other. The first conductive layer and the second layer are arranged one on top of another in such a way that the two diamond structures are arranged at right angles, i.e., 90°, relative to each other. In this case, the surface elements of the first conductive layer are arranged on the "gap" in the free gap between the surface elements of the second conductive layer. In this case, the linear conductor paths of the conductive layer cross in the gap between the surface elements. In this preferred embodiment, the accurate position of the surface elements relative to each other is particularly important and the surface elements are advantageously arranged precisely relative to each other, in particular in the direction of the x and y coordinates, with a tolerance fit of less than 0.25 mm, preferably less than 0.1 mm.

[0150] It is possible here that the conductor path is formed in the area of ​​the surface element according to the shape of the surface element, so that the material forming the conductive layer fills the surface element over the entire surface. It is also possible that the conductor path extends along the surface element, so that the conductor path surrounds the surface element at least partially. In this way, the surface element can be formed by a conductive layer over the entire surface or a conductive layer that is only present locally, especially in an array, which is composed of conductive grid elements and especially transparent non-conductive surface areas between the grid elements. The grid forming the grid element can be regular or irregular. Due to this grid structure, the surface element can be particularly translucent and the surface occupancy of the grid element can be less than 50%.

[0151] Furthermore, it is also possible that the conductive structures of the first electrically conductive layer and the second layer, which are formed by the structured electrically conductive layers and / or electrically conductive regions of the electrically conductive layers, also each have different geometries and / or sizes.

[0152] Advantageously, the contact-making regions, in particular the contact-making structures, of the at least two electrically conductive layers merge into a common contact-making region, thereby making it possible to facilitate contact-making from the outside.

[0153] It is also possible that the common contact area is electrically contacted by means of an adapter element. Thus, for example, it is possible to fix an especially flexible adapter element to the common contact area, which adapter element electrically contacts the contact points in the common contact area and is electrically conductively connected to another contact element on the outside. The contact between the common contact area and the adapter element is preferably realized by means of an electrically conductive adhesive, in particular by means of an ACF bond (ACF=Anisotropie Conductive Film). Here, the electrically conductive adhesive can form a connecting element. The other contact element can be, for example, a standardized plug connector, such as a ZIF connector (ZIF=Zero Insertion Force).

[0154] Advantageously, the conductors consist of a metal, in particular silver (Ag), gold (Au), aluminum (Al), copper (Cu) or chromium (Cr), with a layer thickness of between 1 nm and 100 nm, preferably between 2.5 nm and 75 nm, further preferably between 5 nm and 50 nm. However, it is also possible for the conductors to have a layer thickness of between 100 nm and 5 μm.

[0155] The conductor tracks can also be formed from a conductive paste containing silver (Ag), gold (Au), copper (Cu) and / or carbon.

[0156] Furthermore or additionally, the at least one conductive layer may have at least one ITO (InSnO x = Indium-Tin-Oxide = In2O3: SnO2) and AZO (AlZnO x = aluminum-zinc-oxide = Al:ZnO). The ITO and / or AZO layer is preferably applied over the entire surface by means of magnetron atomization, sputtering or (vacuum) spraying and to a lesser extent by means of CVD and PVD methods and preferably has a layer thickness of 1 nm to 100 μm, more preferably 10 nm to 10 μm.

[0157] Preferably, the ITO and / or AZO layer is arranged directly adjacent to the electrically conductive layer of the metallic material.

[0158] Advantageously, in step b), the at least one electrically conductive layer is a metal layer, and step b) has the further steps of: - vapor-depositing the metal layer; - structuring the metal layer by locally removing the metal layer, in particular by means of photolithography. Thus, in order to form the at least one electrically conductive layer, the carrier substrate is preferably provided with the electrically conductive layer over the entire surface, for example by vapor-depositing or sputtering the metal layer and then, by positive or negative etching or by means of a washing method, the electrically conductive layer is accordingly locally removed again in order to form the electrical functional structures and contact-connecting structures. It is also possible to apply the at least one electrically conductive layer to the carrier substrate by means of a spray mask, by embossing an electrically conductive material and / or by electrically reinforcing the printed structure, in a shape that corresponds to the functional structures and / or contact-connecting structures.

[0159] Preferably, the film comprises a dielectric layer and / or a semiconducting layer which is arranged between a first electrically conductive layer of the at least one electrically conductive layer and a second electrically conductive layer of the at least one electrically conductive layer.

[0160] It is also possible that the at least one conductive layer has a force sensor, in particular for measuring pressure. It is thus possible that, in addition to the x and y coordinates of the position of the contact on a plane determined by the x and y coordinates, which are generated, for example, by a touch sensor area, in particular a capacitive sensor area, the contact strength in the form of a z coordinate (the z coordinate is perpendicular to the x and y coordinates) can also be determined. This allows x, y and z information about the contact to be generated. The z information can be used, for example, to control an electrical functional element of the applied membrane, depending on whether the z information exceeds a predetermined threshold value. Preferably, the force sensor, in particular a force sensor for measuring pressure, is a piezoelectric thin layer. It is also possible that the force sensor is a piezoresistive pressure sensor and / or a piezoelectric pressure sensor. In addition, the force sensor can be an actuator, in particular a key, wherein each of the actuators has at least two electrical states depending on the force acting on the actuator.

[0161] Furthermore, it is possible that the at least one electrically conductive layer has at least partially a surface relief structure, in particular a matte structure. It is thereby possible to deflect light incident on the at least one electrically conductive layer by diffraction, scattering and / or reflection, thereby avoiding the perception that the electrically conductive layer reflects light, in particular by direct specular reflection. Thus, for example, a display with the film applied thereto appears uniformly black in the switched-off state.

[0162] It is also possible that one or more optically effective layers, in particular darkening layers and / or layers with light-scattering properties, at least partially cover the at least one conductive layer when viewed perpendicularly to the plane defined by the carrier matrix. This makes it possible to further reduce the possible visibility of the at least one conductive layer, in particular in the event of direct specular reflection. Thus, for example, the darkening layer absorbs the incident light, whereby the proportion of light reflected by the at least one conductive layer is reduced or reflection is completely avoided. By means of the layer with light-scattering properties, the proportion of light reflected by the at least one conductive layer is also reduced. The layer with light-scattering properties is, for example, a layer having a matte structure with randomly selected relief parameters.

[0163] Furthermore, it is advantageous if the carrier matrix has a layer thickness of between 2 μm and 250 μm, preferably between 23 μm and 125 μm. However, it is also possible for the carrier matrix to have a layer thickness of less than 2 μm.

[0164] The film advantageously has a thickness overall perpendicular to a plane defined by the underside of the carrier substrate of a maximum of 150 μm, preferably 100 μm, further preferably 75 μm.

[0165] Preferably, the carrier substrate is a transparent carrier substrate, in particular a transparent carrier substrate made of PET, PMMA, PC, acrylonitrile butadiene styrene (ABS), PU or glass.

[0166] It is possible for the carrier matrix to be formed from a hybrid material which has a plastic layer and a layer composed of a fiber material.

[0167] The carrier substrate can also be made of a textile, for example a woven fabric.

[0168] Furthermore, the target substrate can be another one-layer or multilayer film. Here, by applying the film according to the invention to the target substrate in the form of the other one-layer or multilayer film, a semi-finished product for further processing is preferably produced.

[0169] According to another embodiment of the invention, the film has at least one intermediate adhesive layer. Thus, one or more further layers can be applied to the film, wherein the one or more further layers are attached via the intermediate adhesive layer.

[0170] Preferably, the at least one electrically conductive layer is arranged between the carrier substrate and the at least one intermediate adhesive layer.

[0171] Furthermore, the at least one intermediate adhesive layer can be arranged on a side of the carrier substrate facing away from the at least one electrically conductive layer. Thus, the method can also have the following step: f) applying the intermediate adhesive layer, in particular, in such a way that the at least one electrically conductive layer is arranged between the carrier substrate and the at least one intermediate adhesive layer and / or when viewed perpendicularly to a plane defined by the carrier substrate, the at least one intermediate adhesive layer at least partially does not cover the at least one contact-making region.

[0172] It is also advantageous if, when viewed perpendicularly to a plane defined by the carrier substrate, the at least one intermediate adhesive layer at least partially does not cover the at least one contact-making area. By ensuring that the intermediate adhesive layer at least partially does not cover the at least one contact-making area, it is ensured that after the film is applied to the target substrate, the electrically functional structure can be contacted reliably and securely.

[0173] It is also expedient if the intermediate adhesive layer does not cover the at least one contact-making region over the entire surface.

[0174] Furthermore, it is advantageous if the intermediate adhesive layer at least partially covers the functional region.

[0175] It is also possible that the at least one intermediate adhesion layer is substantially arranged in the same area as the adhesion promoter layer when viewed perpendicularly to the plane defined by the carrier matrix, in particular the at least one intermediate adhesion layer is substantially arranged to coincide with the adhesion promoter layer when viewed perpendicularly to the plane defined by the carrier matrix.

[0176] The intermediate adhesive layer advantageously has a layer thickness of between 0.1 μm and 50 μm, preferably between 0.25 μm and 25 μm, further preferably between 0.5 μm and 7 μm. Preferably, the intermediate adhesive layer is a primer layer and / or an adhesive layer consisting of a hot melt adhesive, a cold adhesive or a radiation-curable adhesive, in particular an adhesive that can be cured by means of electromagnetic radiation and / or electron radiation. The intermediate adhesive layer is preferably applied by means of gravure printing, screen printing, relief printing or casting technology.

[0177] The film may also have one or more decorative layers.

[0178] Preferably, the one or more decorative layers are arranged on the side of the carrier substrate facing away from the at least one conductive layer. For this reason, the film can have an intermediate adhesive layer in particular to improve the adhesion of the one or more decorative layers. In this way, for example, the intermediate adhesive layer can be applied to the carrier substrate and / or the at least one conductive layer. The one or more decorative layers are applied to the carrier substrate by means of the intermediate adhesive layer. The decorative layer can be applied to the intermediate adhesive layer or directly to the carrier substrate by means of different methods. It is particularly advantageous that the decorative layer has a protective layer as the last layer on the side of the carrier substrate facing away from the at least one conductive layer, which protects the decorative layer, especially from the strong pressure and thermal effects acting, for example, during injection molding and / or lamination. In addition, the protective layer provides protection to prevent mechanical damage, such as scratches, etc., which may occur during the processing process. The protective layer can also contain a film made of a polymer and in particular self-supporting, which is preferably composed of PET, PC or PMMA or of glass or fabric, which remains on the decoration and constitutes a component of a semi-finished product or a finished product.

[0179] Advantageously, the one or more decorative layers are arranged substantially in the same region as the adhesion promoter layer and / or the intermediate adhesion layer, and in particular substantially congruently with the adhesion promoter layer and / or the intermediate adhesion layer when viewed perpendicularly to a plane defined by the carrier substrate.

[0180] Thus, the one or more decorative layers can be applied locally on the side of the carrier substrate facing away from the at least one electrically conductive layer in such a way that they cover essentially the same surface as the adhesion promoter layer on the other side of the carrier substrate. This ensures that the contact-making areas on the side of the carrier substrate facing away from the at least one electrically conductive layer that are not covered by the adhesion promoter layer remain exposed in the same (projected) surface area and that the film can thus form a so-called tail including the contact-making areas, which can be electrically contacted in a particularly simple manner in a subsequent processing step, for example by means of a plug connection.

[0181] The decorative layer or layers can also be arranged on that side of the adhesion promoter layer and / or the intermediate adhesive layer which faces away from the carrier substrate.

[0182] Furthermore, it is also possible for the decorative layer or layers to be arranged on a side of the at least one electrically conductive layer facing away from the carrier substrate.

[0183] The one or more decorative layers are preferably applied substantially congruently with the adhesion promoter layer and in particular the at least one contact area is also uncovered. It may also be advantageous if the decorative layer has a protective layer as the last layer on the side of the at least one electrically conductive layer and / or the intermediate adhesive layer facing away from the carrier substrate, which protects the decorative layer, in particular from strong pressure and thermal effects acting, for example, during injection molding and / or lamination. The protective layer also provides protection against mechanical damage, such as scratches, etc., that may occur during the processing process. The protective layer may also contain a polymeric and in particular self-supporting film, preferably made of PET, PC or PMMA or of glass or fabric, which remains on the decoration and forms a component of the finished product.

[0184] The at least one intermediate adhesive layer is advantageously arranged between the carrier substrate and the decorative layer or layers.

[0185] The one or more decorative layers preferably have at least one layer selected from the group consisting of a protective layer, a color lacquer layer, a metal layer, a reflective layer, a replication lacquer layer, a transparent layer, a carrier layer and / or a layer generating a changing visual effect.

[0186] Thus, the one or more decorative layers can, for example, comprise a printed layer, in particular composed of an opaque and / or colored ink, which forms an outer frame around the functional area. The decorative layer can also be applied in a covering film and in particular covering the functional area over the entire surface or in parts and / or in a grid. The decorative layer can form a uniform surface and / or a continuous pattern and / or a single picture theme. The decorative layer can be opaque and / or translucent and / or transparent over the entire surface or in parts, in particular transparently dyed.

[0187] Thus, for example, the one or more decorative layers can be applied, in particular embossed and / or printed onto the adhesion promoter layer and / or the intermediate adhesion layer. The one or more decorative layers can be applied, for example, by hot embossing and / or by cold embossing and / or by heat transfer and / or by different lamination methods and / or other known methods, to the side of the adhesion promoter layer and / or the intermediate adhesion layer facing away from the carrier matrix. Thus, for example, the film can be provided with a decorative layer or decoration, so that the film has a decoration in addition to the function in the form of a touch sensor area provided by the electrical functional structure. The one or more decorative layers can include other layers, for example protective lacquer layers and / or colored layers and / or metal layers and / or transparent reflective layers and / or replica lacquer layers and / or different types of layer structures that generate varying visual effects.

[0188] Furthermore, it is possible for the one or more decorative layers to have at least two decorative layers, in particular a first decorative layer and a second decorative layer.

[0189] It is also possible that the one or more decorative layers are arranged on the side of the carrier substrate facing away from the at least one electrically conductive layer and also on the side of the at least one electrically conductive layer facing away from the carrier substrate. Thus, for example, it is possible that a first decorative layer is arranged on a first side of the carrier substrate and a second decorative layer is arranged on a side of the carrier substrate opposite the first side, so that the one or more decorative layers are arranged on both sides of the carrier substrate.

[0190] It is also advantageous that at least two decorative layers interact in such a way that special visual effects, such as a visual stereoscopic effect and / or a special visual superposition effect, are generated. For example, a first decorative layer facing the observer can form a color filter layer of a second decorative layer facing away from the observer, i.e., located below it in the viewing direction, which is, for example, a colored layer. It is also possible to achieve superposition effects or combination effects with two patterns, which are supplemented by moiré patterns or other supplementary combination patterns are generated in the superposition.

[0191] In addition, variable visual combination effects can be achieved, which are first produced by the superposition of at least two decorative layers. It may be advantageous that the decorative layers are spaced apart from each other, for example because in particular a carrier matrix and a conductive layer and, if necessary, other layers, in particular transparent layers, are arranged between the decorative layers. Such a distance may be advantageous in particular for producing a three-dimensional and / or variable visual effect. The three-dimensional effect can be produced, for example, in that an optically transparent layer is embedded in the viewing direction before and / or after the decorative layer and / or as a component of the decorative layer. The optically transparent layer preferably has the same layer thickness as the corresponding decorative layer or has a layer thickness that is several times thicker than the corresponding decorative layer, the layer thickness of the optically transparent layer being in particular between 0.5 μm and 500 μm, preferably between 10 μm and 100 μm. The optically transparent layer is preferably made of an optically transparent lacquer and / or of an optically transparent film that preferably contains PET, PMMA or PC.

[0192] For example, a changing visual effect can be achieved by arranging the aforementioned optically transparent layer as a spacer layer between a reflective layer and a semi-transparent reflective layer and causing interference effects in this layer structure, which can be seen by viewing angle-dependent and / or illumination angle-dependent color change effects. Such interference layer structures are known as Fabry-Perot film structures.

[0193] Furthermore, it is advantageous if at least one of the one or more decorative layers has, at least in places, a surface relief, in particular a haptic and / or tactilely perceptible surface relief.

[0194] It is also possible that, by structuring the optically transparent layer and / or the protective layer and / or the one or more decorative layers, a surface morphology, in particular a surface relief structure, is generated, which in particular achieves a tactile or tactile effect. It is also possible that the surface relief structure produces a diffractive and / or refractive visual effect. These surface relief structures can be produced by additional locally printed paint or mechanical or optical structuring of the layer surface. The mechanical structuring can be a replica structure formed using a correspondingly shaped embossing tool. The optical structuring can be laser ablation. In addition, photolithographic methods can also be used to produce these structures. The structural depth for this tactile effect is in particular 1 μm to 2000 μm, preferably 50 μm to 2000 μm. The structural depth for the diffraction or refraction effect is in particular 0.1 μm to 20 μm, preferably 0.1 μm to 5 μm.

[0195] It is also possible to only imitate such a tactile surface undulation structure, because the real tactile structure is usually mechanically sensitive, especially to scratches and / or wear, and is also easier to get dirty than a smooth surface. For this reason, it is reasonable to introduce the tactile structure into the corresponding surface and / or apply it thereto, as described above. A transparent cover layer can then be applied to the surface, which seals the tactile structure and has a smooth surface outward. The cover layer is preferably highly transparent and thicker than the height of the tactile structure, preferably at least twice as thick. In addition, the cover layer preferably has a refractive index that deviates by at least 0.2 compared to the layer with the tactile structure below it, so as to provide an optical interface, thereby improving the visibility of the tactile structure. For this reason, the cover layer can contain nanoscale particles, which are used to modulate the refractive index, and the particles are composed of one or more components, which are selected from TiO2, SiO2, Sn- or metal chalcogenides (oxides\sulfides), and the cover layer can also contain metals Au, Ag, Cu.

[0196] The tactilely perceptible and / or only visually simulated tactile surface relief structure can correspond to the functional touch sensor area, that is to say highlight or mark its functional area, so that the touch function can be felt "blindly". However, it is also possible to provide a tactilely perceptible and / or only visually simulated tactile structure over the entire surface in order to achieve a certain surface property of the target substrate, in particular in conjunction with its other visual perception. Both possibilities can also exist in combination. Thus, for example, it is possible to combine a wood decoration with a tactile wood texture, modifying the wood texture in the area of ​​the touch function, in particular in the functional area, in terms of structural depth and / or other structural parameters, so that within the texture, the touch sensor area is perceptible to the user.

[0197] The membrane may also have a construction in the following order:

[0198] -Carrier matrix

[0199] -Separation layer

[0200] - Protective paint

[0201] - Primer layer

[0202] - at least one conductive layer

[0203] -Intermediate adhesive layer

[0204] - the one or more decorative layers

[0205] - Adhesion promoter layer.

[0206] The film can also comprise an adhesive layer on that side of the carrier substrate which faces away from the at least one electrically conductive layer.

[0207] The film can therefore have an adhesion promoter layer on one side of the carrier substrate and an adhesive layer on the other side of the carrier substrate, so that the film can be applied to another substrate by means of the adhesive layer. The film can be applied to the other substrate, for example, by means of hot lamination or by means of back injection. In particular, during back injection of the film, the at least one electrically conductive layer and / or the one or more decorative layers are protected by the carrier substrate from the injected injection molding material and in particular from the harsh process conditions associated with high pressures and high temperatures during the injection molding process.

[0208] It is also advantageous that the film has at least one alignment mark to determine the relative orientation or position of the functional area of ​​the film, especially the at least one conductive layer and / or the at least one contact connection area. Alignment or alignment accuracy refers to the arrangement structure of the layers stacked or side by side relative to each other in the case of maintaining the desired position tolerance. It can be ensured by the alignment mark that the film can be applied to the target substrate in the case of maintaining the desired position tolerance. Preferably, the alignment mark is formed by a printed material and / or a magnetic or conductive material. The mark can be, for example, an optically readable alignment mark, which is distinguished from the background by its color tone, its opacity or its reflective properties. But the alignment mark can also be an alignment mark detectable by a magnetic or conductive sensor. The alignment mark is detected by an optical sensor, especially a camera, a magnet sensor or a mechanical sensor, a capacitive sensor or a conductive sensor, and then the application of the film can be controlled by the alignment mark. It is thus possible to arrange the film position accurately on the target substrate by the alignment mark. Thus, the same manufacturing quality of, for example, a touch screen can be improved and the waste caused by the wrong positioning of the film on the target substrate can be further reduced at the same time.

[0209] Preferably the film is a thermally laminated film.

[0210] Next, a method for manufacturing an electrical functional element and a preferred design of the electrical functional element are mainly described:

[0211] It is also advantageous if, in step b), the film is applied from a roll to the target substrate by means of hot lamination, in particular at a film web speed of between 1.5 m / min and 3.5 m / min. It is possible for the roll to have a film web as raw material, which comprises a plurality or a large number of films, in particular films according to the invention. This makes it possible, in particular, to further improve industrial mass production. Thus, for example, the film can be applied to the target substrate over its entire surface by means of a hot laminator, thereby further reducing the time, labor and logistics costs and at the same time ensuring that the same production quality is achieved.

[0212] It is also advantageous that in step b) the film from the sheet is applied to the target substrate by means of hot lamination. It is possible that the sheet has a plurality or a large number of films, in particular according to the invention, as raw material. This makes it possible, in particular, to further improve industrial mass production. For example, the film can be applied to the target substrate over its entire surface by means of a hot laminator, thereby further reducing the time, labor and logistics costs and at the same time ensuring that the same production quality is achieved.

[0213] The sheet or sheet can also have only one film, in particular according to the invention, as raw material. A plurality of such printed sheets, each comprising a film, can be present in a silo, in particular as a stack, and can be fed individually to a hot laminator and / or injection molding machine, which can be operated, for example, with a reciprocating or rolling motion, for application to a target substrate. The application to the target substrate can then be achieved with positional accuracy, as described above, by means of alignment marks on the film.

[0214] It is also advantageous that, before being applied to the target substrate, one or more films, in particular according to the invention, are separately arranged releasably on an intermediate substrate, which can be present as a roll or as a sheet. The intermediate substrate can be, for example, a paper coated with silicone or a film web provided with a peeling layer. In this way, in a subsequent heat transfer step and / or in a subsequent injection molding process, one or more films can be transferred from the intermediate substrate to the target substrate together or separately by means of the applied heat and / or pressure. Subsequently, the intermediate substrate can be removed, in particular, from the film fixedly attached to the target substrate.

[0215] Furthermore, it is possible to carry out the hot lamination at a temperature in the range of between 80°C and 300°C, preferably between 200°C and 290°C, further preferably between 240°C and 270°C and / or at an embossing pressure in the range of between 200 bar and 2000 bar, preferably between 500 bar and 1500 bar.

[0216] It is also possible that, as an alternative to hot lamination, in step b), the film is applied to the target substrate by spraying in a molding material, wherein the molding material in particular forms the target substrate. In this way, the film can be fixedly connected to the molding material via the adhesion promoter layer.

[0217] The membrane can also be connected to another substrate by injection molding material.

[0218] It is also advantageous, especially when the film is designed as a transfer film, to apply the film to the target substrate by means of hot embossing in step b). It is possible here to apply the film from a roll or a printed sheet or a sheet to the target substrate by means of hot embossing.

[0219] It is possible that the roll has as raw material a film web comprising a plurality or a plurality of films, in particular according to one of the films of the invention, and / or that the printed sheet has as raw material a plurality or a plurality of films, in particular according to the invention. This makes it possible, in particular, to further improve industrial mass production. For example, the film can be applied to the target substrate over its entire surface by means of a hot laminator, thereby further reducing the time, labor and logistics costs and at the same time ensuring that the same production quality is achieved.

[0220] Furthermore, it is expedient if the embossing temperature is in the range of 80° C. to 250° C., preferably in the range of 100° C. to 200° C., and / or the embossing pressure is 0.5 kN / cm 2 Up to 10kN / cm 2 It is also suitable that the embossing time is in the range of 1 ms to 2000 ms, preferably in the range of 1 ms to 500 ms.

[0221] Furthermore, it is possible that the further substrate and / or the target substrate is flat and / or has a one-dimensionally curved and / or a two-dimensionally curved and / or a three-dimensionally curved shape.

[0222] It is also possible to shape the film and / or the electrical functional element, in particular the electrical functional element formed from the target substrate and the film, in particular to shape it three-dimensionally.

[0223] Advantageously, the shaping is carried out by a shaping process, preferably by deep drawing, hot forming, high pressure forming and / or by means of a tape casting process. Preferably, the target substrate and / or the intermediate substrate has a layer thickness of a maximum of 1 mm, preferably 500 μm, so that the electrical functional element formed by the film and the target substrate is shapeable.

[0224] In the following, preferred shaping processes for shaping films and / or electrical functional elements are mainly described, wherein in particular the electrical functional element is formed by a film arranged, in particular applied, on a target substrate:

[0225] Preferably, the membrane and / or the electrical functional element are formed by deep drawing. Advantageously, the membrane and / or the electrical functional element are formed in a forming mold corresponding to the desired forming geometry with the aid of a vacuum, in particular a negative pressure of up to 1 bar, and / or with the aid of an overpressure, in particular an overpressure between 1 bar and 3 bar.

[0226] Furthermore, it is possible to shape the film and / or the electrical functional element by means of thermoforming. Advantageously, the shaping process or the process parameters of the shaping process of the film and / or the electrical functional element correspond to the shaping process / shaping parameters of deep drawing, wherein the shaping is carried out with additional temperature assistance, in particular at a temperature between 120° C. and 300° C., preferably at a temperature between 190° C. and 250° C., for example when using ABS material. It is possible here that the carrier matrix and / or the target matrix contains ABS material.

[0227] The film and / or the electrical functional element can also be formed by means of high pressure forming. Advantageously, the forming of the film and / or the electrical functional element is carried out here with the aid of overpressure, in particular at an overpressure of between 1 bar and 300 bar, preferably between 10 bar and 150 bar, in a forming mold corresponding to the desired forming geometry. It is expedient here to form with the aid of additional temperature, preferably at a temperature in the range of the glass transition temperature of the film used. Advantageously, for example when using ABS material, the temperature is here between 120° C. and 300° C., preferably between 190° C. and 250° C.

[0228] By means of the above-mentioned forming process, a three-dimensional stretching of up to 200% is preferably carried out. In particular, when the parameters are optimized for the corresponding system, a stretching of up to 300% can also be achieved, wherein in many cases of use, a stretching between 20% and 50% is sufficient.

[0229] Furthermore, it is possible for the film and / or the electrical functional element which has been shaped or pre-shaped by means of the above-described shaping process to be pre-injected and / or back-injected in a subsequent injection molding process.

[0230] It is also possible that the film and / or the electrical functional element are shaped and / or deformed by means of an injection molding process. Advantageously, the film and / or the electrical functional element are introduced into the injection mold in a flat state by a roll or by a printed sheet or sheet or by a single sheet and deformed by means of an injection molding method, in particular wherein the molding is carried out by closing the mold and also by spraying in the molding material. In particular, the injection pressure is related to the component geometry and / or the component size here. For example, it is possible that the injection pressure is 500 bar and the injection temperature is between 180°C and 380°C, wherein the injection pressure and the injection temperature are related to the injection molding material. It is also suitable that the film and / or the electrical functional element introduced into the injection mold are heated by means of the film and / or the electrical functional element, for example, at a temperature between 30°C and 300°C, preferably between 80°C and 150°C, before the closing process of the injection mold. It is also possible that the film and / or the electrical functional element are matched or fixed to the cavity by means of a clamping frame and / or a vacuum and / or an overpressure.

[0231] It is also advantageous if the film and / or the electrical functional element is formed by “pushing” the film and / or the electrical functional element onto an already three-dimensionally preformed component.

[0232] Advantageously, the membrane and / or the electrical functional element is "slipped on" during the treatment process by vacuuming the control membrane and / or the electrical functional element onto the already three-dimensionally preformed component while applying an overpressure. Preferably, the already three-dimensionally preformed component to be slipped on is previously subjected to temperature. It is expedient here for the overpressure to be between 1 bar and 50 bar, preferably between 3 bar and 15 bar, and / or for the temperature to be between 30° C. and 300° C., preferably between 100° C. and 180° C.

[0233] Preferably, the film and / or the electrical functional element has a stretchability of more than 20%. Such a high stretchability cannot be achieved with conventional functional films, for example by means of the above-mentioned forming and / or deformation processes, especially because carrier films such as PET do not have sufficient deformability and / or the conductive structure breaks after a small deformation, especially when stretched by more than 20%. Here, it is shown that the stretching is improved by the film according to the invention. In this way, by the multi-layer structure of the film according to the invention, in particular by embedding the at least one conductive layer between multiple paint layers according to the sandwich system as described above, it is achieved that the mechanical stretching and / or deformation can be influenced in a targeted manner, for example, in that the area of ​​the film determined by the thickness of the adaptation layer and / or the paint formula can be designed to be more flexible or less flexible. Therefore, it is preferred to achieve the desired stretchability of more than 20% here.

[0234] In the above-mentioned three-dimensional deformation, it is also advantageous that the electrically functional structure membrane and / or the electrically functional element can be electrically, especially galvanically contacted from the outside, for which purpose the electrical contacts must be accessible for contacting. Alternatively, inductive and / or capacitive coupling, especially coupling via antennas, can be used. As stated above, the membrane according to the invention enables stable and reliable contacting of the electrically functional structure.

[0235] Furthermore, it is possible that the adhesion promoter layer is made of a material whose visual appearance changes from turbid to highly transparent and / or clear during and / or after step b). It is thus possible that during the application of the film to the target substrate, the adhesion promoter layer melts due to the supplied heat and / or the adhesion promoter layer is flattened by means of pressure, so that the surface roughness of the adhesion promoter layer that is present in the state where the film has not been applied is flattened during and / or after the application. The visual appearance of the adhesion promoter layer thus changes from turbid to highly transparent and / or clear.

[0236] After the film is applied to the target substrate, the film and the target substrate form an electrical functional element. Advantageously, after the film is applied to the target substrate, the adhesion promoter layer of the film is highly transparent, especially the adhesion promoter layer of the film has a transmittance of more than 85%, preferably more than 90% for light in the wavelength range between 380nm and 780nm, and / or the adhesion promoter layer of the film is a clear adhesion promoter layer, especially the proportion of light in the wavelength range between 380nm and 780nm that is diverted by the adhesion promoter layer of the film through scattering is less than 8%, preferably less than 4%. The film can also have a transmittance of more than 75%, preferably more than 80%, further preferably more than 85%, and further preferably more than 90% for light in the wavelength range between 380nm and 780nm at least in the functional area of ​​the at least one conductive layer. Thus, for example, an outstanding and faithful look and feel of the image produced by the display can be achieved, and the film is applied to the display.

[0237] It is also possible that the electrical functional element is a functional element for information processing, in particular a mobile phone, such as a smartphone or a PDA, a tablet computer, an ATM, a ticket machine, an arcade machine, a game machine, an operating part of a household appliance or a motor vehicle or, for example, a touch screen. It is also possible that the electrical functional element is an input device, in particular a touch pad. However, it is also possible that the electrical functional element is a semi-finished product, which is installed as a finished product or in a finished product in further processing steps. In this way, the film can be applied to a glass layer, for example, and the electrical functional element formed by the glass layer and the film can be installed, for example, in a ticket machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0238] Exemplary embodiments of the invention are explained below by way of example with reference to drawings which are not true to scale.

[0239] Figures 1a to 1f A cross-sectional view of the membrane is schematically shown;

[0240] Figure 2a and Figure 2b A cross-sectional view of the membrane is schematically shown;

[0241] Figure 3 A cross-sectional view of the membrane is schematically shown;

[0242] Figures 4a to 4c A cross-sectional view of the membrane is schematically shown;

[0243] Figure 5a to Figure 5c A cross-sectional view of the membrane is schematically shown;

[0244] Figures 6a to 6c A cross-sectional view of the membrane is schematically shown;

[0245] Figure 7 A cross-sectional view of the membrane is schematically shown;

[0246] Figure 8 A cross-sectional view of the membrane is schematically shown;

[0247] Fig. 9 A cross-sectional view of the membrane is schematically shown;

[0248] Fig.10 A cross-sectional view of the membrane is schematically shown;

[0249] Fig.11a Schematic diagram of a top view of a conductor track

[0250] Fig.11b Schematically shown Fig.11a An enlarged portion of

[0251] Fig.12 A schematic top view of a conductor line is shown;

[0252] Fig.13 A cross-sectional view of the membrane is schematically shown;

[0253] Fig.14 Schematically showing a top view of the membrane;

[0254] Fig.15a and Fig.15b Schematically showing the method steps for producing an electrical functional element;

[0255] Fig.16a and Fig.16b Schematically showing the method steps for producing an electrical functional element;

[0256] Fig.17a and Fig.17b Schematically showing the method steps for producing an electrical functional element;

[0257] Fig.18a and Fig.18b Schematically showing the method steps for producing an electrical functional element;

[0258] Fig.19a and Fig.19b Schematically showing the method steps for producing an electrical functional element;

[0259] Fig.20a and Fig.20b Schematically showing the method steps for producing an electrical functional element;

[0260] Fig.21a and Figure 21b Schematically showing the method steps for producing an electrical functional element;

[0261] Fig.22a and Figure 22b Schematically showing the method steps for producing an electrical functional element;

[0262] Figures 23a to 23d Schematically showing a top view of a target substrate, a membrane, and an electrical functional element;

[0263] Figures 24a to 24e The method steps for producing the membrane are schematically shown;

[0264] Fig.25a and Fig.25b The method steps for producing the membrane are schematically shown;

[0265] Figures 26a to 26c Schematically showing method steps for forming a membrane and / or an electrically functional element; DETAILED DESCRIPTION

[0266] Figure 1a A film 1 is shown having a carrier matrix 2 , an electrically conductive layer 3 and an adhesion promoter layer 4 .

[0267] The carrier matrix 2 is preferably a layer of PET, PMMA, PC, ABS, PU, ​​glass or fabric. The carrier matrix 2 can also be formed from a hybrid material having a plastic layer and a fabric, in particular a fiber material, such as paper, cotton or other layers made of natural or artificial fibers. The carrier matrix 2 preferably has a layer thickness of between 2 μm and 250 μm, preferably between 23 μm and 125 μm. Figure 1a The carrier substrate 2 shown in FIG. 1 is a transparent layer PET with a layer thickness of 75 μm.

[0268] Transparency here refers to the property of a substance that allows light in the wavelength range visible to the human eye to pass through, in particular in the wavelength range between 380 nm and 780 nm.

[0269] The conductive layer 3 is preferably a metal layer, in particular a layer composed of silver (Ag), gold (Au), aluminum (Al), copper (Cu) or chromium (Cr). The conductive layer 3 preferably has a layer thickness between 1 nm and 100 nm, more preferably between 2.5 nm and 75 nm, and even more preferably between 5 nm and 50 nm. The layer thickness of the conductive layer 3 can also be between 100 nm and 5 μm. The conductive layer 3 can also be composed of a conductive paste containing silver (Ag), gold (Au), copper (Cu) and / or carbon. Figure 1a The conductive layer 3 shown in FIG. 5 is a layer of Ag with a layer thickness of 50 nm.

[0270] The conductive layer 3 is shaped in such a way that the conductive layer 3 has a plurality of conductor tracks, which have a width 26 of between 0.2 μm and 20 μm, preferably between 4 μm and 15 μm, and are at a distance 27 from one another that is greater than 10 μm, preferably greater than 20 μm, so that the conductor tracks are below the resolution capability of the human eye. Conductor tracks here preferably refer to the structured conductive layer and the conductive areas of the at least one conductive layer 3. The conductor tracks are applied in such a way that sufficient transparency for the human eye is retained, that is to say the conductor tracks are designed in such a way that they are not noticeable to a human observer because the conductor tracks are below the resolution capability of the human eye. Despite the use of narrow conductor tracks, sufficient electrical conductivity, in particular comparable to a layer of indium tin oxide (ITO), is achieved. Preferably, the at least one conductive layer 3, in particular the conductor tracks, occupies less than 30%, preferably less than 20%, further preferably less than 10%, and further preferably less than 5% of the carrier substrate 2. In Figure 1a In FIG. 2 , the width 26 of the conductor tracks formed by the conductive layer 3 is 5 μm and the distance 27 of the conductor tracks formed by the conductive layer 3 is 15 μm.

[0271] The conductive layer 3 forms an electrical functional structure in the functional area 21, which forms a touch sensor area, in particular a capacitive sensor area. It is also possible that the electrical functional structure forms a resistive or inductive sensor area. The touch sensor area provides a touch area function. The touch sensor area is here a contact-sensitive sensor that enables control of an electrical functional element, such as a smartphone, a game console or a ticket vending machine. The touch sensor area is also a multi-touch sensor area that can process multiple simultaneous contacts, for example for enlarging and rotating an image, in particular for displaying the image on a display that is arranged below the touch sensor area and is not shown in detail here.

[0272] The conductive layer 3 furthermore has a contact region 20. The contact region 20 forms a contact structure for electrically contacting a functional structure. The contact structure in the functional region 20 is, for example, an electrical terminal in the form of a plug. It is also possible that the contact structure has so-called pins, contacts and / or pins. The contact region 20 is Figure 1a The conductive layer 3 has an area of ​​0.3 mm×2.0 mm. It is also possible that the conductive layer 3 forms one or more contact areas 20 separated from each other. Separation here means that the contact areas are spaced apart from each other and are thus also electrically insulated from each other, in particular the contact areas are at least 0.1 mm, preferably at least 0.2 mm, and further preferably at least 0.5 mm apart from each other.

[0273] The adhesion promoter layer 4 is preferably a layer of a polymer and / or copolymer, in particular comprising PMMA, polyester, PU or PVC, having a layer thickness of between 0.1 μm and 50 μm, preferably between 0.25 μm and 25 μm, further preferably between 0.5 μm and 7 μm. Figure 1a The adhesion promoter layer 4 shown in FIG. 5 is a layer of a PVC copolymer having a layer thickness of 4 μm.

[0274] As in Figure 1a As shown in FIG. 1 , the conductive layer 3 is arranged between the carrier matrix 2 and the adhesion promoter layer 4. That is, the adhesion promoter layer 4 is arranged on the side of the at least one conductive layer 3 facing away from the carrier matrix 2. The membrane 1 has an upper side 40 and a lower side 41, wherein the adhesion promoter layer 4 is arranged on the upper side 40. As shown in FIG. Figure 1a As shown in FIG. 1 , an adhesion promoter layer 4 is arranged on the surface of the film 1 .

[0275] The adhesion promoter layer 4 is arranged in the region 22. The region 22 completely covers the Figure 1a In the functional region 21, the functional structure formed by the conductive layer 3 is shown. In the region 23, no adhesion promoter layer 4 is provided. The region 23 has a contact-making region 20 of the conductive layer 3, so that the adhesion promoter layer 4 does not cover the contact-making region 20 over the entire surface. The region 23 does not adhere to the target substrate when the film 1 is applied to the target substrate, so that in particular the contact-making region 20 is accessible after the film 1 is applied to the target substrate and can reliably contact the electrical functional structure.

[0276] However, it is also possible that the adhesion promoter layer 4 does not completely cover the functional region 21 . Thus, the adhesion promoter layer 4 can, for example, cover at least 30%, preferably at least 50%, further preferably at least 70% of the functional region 21 .

[0277] The adhesion promoter layer 4 is preferably made of a material that is highly transparent after the film 1 is applied to the target substrate. The term "highly transparent" describes the property of a substance that allows light in the wavelength range visible to the human eye, in particular in the wavelength range between 380 nm and 780 nm, to pass through almost unimpeded and without any hindrance. A highly transparent layer therefore has a light absorption that is essentially imperceptible to a human observer, so that a reduction in light intensity when light passes through the layer is almost imperceptible to a human observer.

[0278] The adhesion promoter layer 4 is thus preferably made of a material which, after being applied to the target substrate, has a transmittance of more than 85%, preferably more than 90%, for light in the wavelength range between 380 nm and 780 nm.

[0279] The bonding agent layer 4 is preferably made of a material which is clear after the film 1 is applied to the target substrate, so that after the film 1 is applied to the target substrate, less than 8%, preferably less than 4%, of the light in the wavelength range between 380 nm and 780 nm is deflected by the bonding agent layer 4 by scattering.

[0280] As explained above, the adhesion promoter layer 4 can have light-scattering properties in the state before it is applied to the target substrate, in particular due to the surface roughness of the adhesion promoter layer 4, which can be generated, for example, by the path of process steps for applying the adhesion promoter layer 4. When the film 1 is applied to the target substrate and the adhesion promoter layer 4 is melted and / or flattened, for example by means of heat and / or pressure supplied by hot lamination, the adhesion promoter layer 4 is now particularly highly transparent and / or clear, so that the surface roughness of the adhesion promoter layer 4 no longer appears to be disruptive in the external appearance. That is to say, due to the physical and / or chemical changes of the adhesion promoter layer 4 during or after the film 1 is applied to the target substrate, the adhesion promoter layer 4 is highly transparent and / or clear.

[0281] The locally applied adhesion promoter layer 4 is preferably a layer of hot melt adhesive, cold adhesive or radiation-curable adhesive, in particular an adhesive that can be cured by electromagnetic radiation and / or electron radiation. Radiation-curable adhesives are cured, for example, by UV light and / or IR light (UV = ultraviolet light; IR = infrared light).

[0282] Figure 1b A film 1 is shown which has a carrier matrix 2 , an electrically conductive layer 3 , a protective lacquer layer 6 , a contact reinforcing layer 7 and an adhesion promoter layer 4 .

[0283] The protective lacquer layer 6 is preferably a layer of PMMA, polyester, PU or PVC, which has a layer thickness between 0.1 μm and 50 μm, preferably between 0.25 μm and 25 μm, further preferably between 0.5 μm and 15 μm. Figure 1bThe protective lacquer layer 6 shown in FIG. 1 is a transparent layer of PAC with a layer thickness of 5 μm.

[0284] The protective varnish layer 6 covers the conductive layer 3, but does not cover the contact area 20. Thus, the protective varnish layer 6 covers the functional area 21 formed by the conductive layer 3, but does not cover the contact area 20. Figure 1b As shown, the protective lacquer layer 6 is arranged on the side of the electrically conductive layer 3 facing away from the carrier substrate 2. That is to say, the protective lacquer layer 6 is arranged between the electrically conductive layer 3 and the adhesion promoter layer 4.

[0285] The contact reinforcement layer 7 is preferably a layer composed of an electrically conductive paste, in particular a carbon paste, which contains silver (Ag), gold (Au), aluminum (Al), copper (Cu), chromium (Cr) and / or other electrically conductive metals. It is also possible that the electrically conductive paste, in particular a carbon paste, has a binder, in particular rosin and / or phenolic resin, polymers and copolymers.

[0286] A binder is a material by which solids can be connected to one another or to a base, especially in fine dispersion. It is possible to add the binder in liquid form to the solids to be bonded.

[0287] The binder of the conductive paste, in particular the carbon paste, is a natural resin, preferably rosin, phenolic resin, polymers and copolymers consisting of PVC, PMMA, PU, ​​polyester, isocyanate (NCO) crosslinked binders, such as MF, MPF, melamine polyester, UMF. To a lesser extent, the conductive paste contains binders of poly(organo)siloxanes and copolymers thereof and / or radiation-curing binders.

[0288] The lacquers and pastes may, for example, be solvent-based or be present as water-based emulsions, dispersions or suspensions.

[0289] The contact strengthening layer 7 preferably has a layer thickness of between 0.1 μm and 100 μm, preferably between 0.25 μm and 25 μm, further preferably between 0.5 μm and 10 μm.

[0290] exist Figure 1b The contact strengthening layer 7 shown in FIG. 1 is a layer of carbon paste with a layer thickness of 4.5 μm.

[0291] Here, a contact strengthening layer 7 is applied to the contact connection region 20 of the conductive layer 3. The conductive layer 3 has the contact strengthening layer 7 in the contact connection region 20. Figure 1bAs shown in FIG, the contact strengthening layer 7 is applied over the entire surface in the contact-making region. However, it is also possible to apply the contact strengthening layer 7 only locally in the contact-making region 20. The contact strengthening layer 7 protects the contact-making region 20 or the contact-making structure formed in the contact-making region 20 from mechanical, physical and / or chemical environmental influences.

[0292] As in Figure 1b As shown in , the adhesion promoter layer 4 is present in region 22 and is not present in region 23. When observed perpendicularly to the plane defined by the carrier substrate 2, the adhesion promoter layer 4 is therefore not present in region 24 surrounded by region 23. Region 24 is adjacent to the contact-making region 20 and does not have an adhesion promoter layer 4. The adhesion promoter layer 4 is applied only in region 22 and does not cover the region 24 adjacent to the contact-making region 20. When the film 1 is applied to the target substrate, the film 1 is therefore attached to the target substrate only in region 22. In region 23 having regions 20 and 24, the film 1 is not attached to the target substrate, so that the contact-making region 20 is accessible. In addition, region 23 can be lifted, wherein the region 24 adjacent to the contact-making region 20, for example, performs a hinge function to lift region 23.

[0293] Region 24 preferably has a width of at least 0.2 mm, preferably at least 0.5 mm, further preferably at least 1 mm, still further preferably at least 2 mm. Figure 1b The region 24 shown in the figure has a width of 1 mm. The width of the region 24 can be selected according to the requirements of the target substrate or according to further processing steps after applying the film 1 to the target substrate, to which the film 1 should be applied. The width here refers to the distance between the interface 42 formed by the contact area 20 and the region 24 adjacent to the contact area 20 and the interface 43 formed by the adhesion promoter layer 4 and the region 24 adjacent to the contact area 20.

[0294] About Figure 1b For the design of other layers in the embodiment, please refer to the above embodiment.

[0295] Figure 1c The film 1 is shown, which comprises a carrier matrix 2 , an electrically conductive layer 3 , an adhesion promoter layer 4 , a release layer 5 , a protective lacquer layer 6 and a contact reinforcing layer 7 .

[0296] The peeling layer 5 is preferably a layer of wax, polyethylene (PE), polypropylene (PP), cellulose derivatives or poly(organic)siloxanes. The aforementioned wax may be a natural wax, a synthetic wax or a combination thereof. The aforementioned wax is, for example, palm wax. The aforementioned cellulose derivative is, for example, cellulose acetate (CA), cellulose nitrate (CN), cellulose acetate butyrate (CAB) or a mixture thereof. The aforementioned poly(organic)siloxane is, for example, a silicone binder, a polysiloxane binder or a mixture thereof. The peeling layer 5 preferably has a layer thickness between 0.1 μm and 10 μm, preferably between 0.01 μm and 5 μm. Figure 1c The release layer 5 shown in FIG. 5 is a layer of PE wax dispersion with a layer thickness of less than 1 μm.

[0297] As in Figure 1c As shown in FIG, the release layer 5 covers the entire area 24 adjacent to the contact-making area 20. The contact-making area 20 is only partially covered by the release layer 5. However, it is also possible that the release layer covers the entire area of ​​the contact-making area 20. It is also possible to apply the release layer in the contact-making area 20, but not in the area 24 adjacent to the contact-making area 20, entirely or at least partially.

[0298] The release layer 5 prevents the area to which the release layer 5 is applied from adhering to the target substrate to which the film 1 is applied. Figure 1c The film 1 shown in FIG. 1 adheres to the target substrate in region 22 after application to the target substrate, but does not adhere to the target substrate in region 23 with regions 20 and 24. The release layer 5 can thus ensure that the region with the release layer 5 does not adhere to the target substrate, for example, by thermal lamination onto the target substrate.

[0299] About Figure 1c For other layer designs in the embodiment, please refer to the above-mentioned embodiment.

[0300] Advantageously, after being applied to the target substrate, the film 1 has a transmittance of more than 75%, preferably more than 80%, further preferably more than 85%, and still further preferably more than 90% at least for light in the wavelength range between 380 nm and 780 nm in the functional area formed by the conductive layer 3.

[0301] The transmittance describes here the permeability of the film 1 for light in the wavelength range between 380 nm and 780 nm. The light incident on the film 1 is partially reflected at the air-film 1 interface and at the interfaces of the layers of the film 1. In addition, the light incident on the film 1 is partially absorbed when traversing the film 1. The remaining portion of the light is transmitted through the film 1 and is emitted again on the opposite side of the film 1. In order to determine the transmittance τ, the quotient of the light intensity I behind the film and the light intensity I0 in front of the film is calculated. The transmittance τ is a measure of the "allowed to pass" intensity and has a value between 0 and 1. The transmittance is usually related to the wavelength of the incident light.

[0302] As explained before, the adhesion promoter layer 4 can have a cloudy visual appearance before the film 1 is applied to the target substrate, which is caused in particular by the surface roughness of the adhesion promoter layer 4. After the film 1 is applied to the target substrate, the surface roughness is flattened, for example by heat supplied during the application process that can melt the adhesion promoter layer 4 and / or by the applied pressure, which flattens the adhesion promoter layer by pressing against the target substrate. As a result, the adhesion promoter layer is highly transparent and / or clear, especially after application to the target substrate, so that the cloudy visual appearance disappears and high transmission values ​​of the applied film 1 can be achieved. Therefore, it is preferred to measure the transmittance of the film 1 after application to the target substrate as explained below.

[0303] If the film 1 is applied, for example, to a target substrate of PMMA and the total transmittance of the electrical functional element formed by the target substrate and the film 1 is then determined, a total transmittance of 84.6% is obtained. This total transmittance is obtained both in the measurement of the side of the PMMA target substrate 10 and in the measurement of the side of the carrier substrate 2 of the film 1. The PMMA target substrate has a transmittance of 93.6% here. The measuring instrument Byk Gardener Haze-Gard Plus of BYK-Gardner GmbH in Geretsried, Germany, is used to measure the total transmittance and the transmittance of the PMMA target substrate.

[0304] Figure 1d The film 1 is shown, which comprises a carrier matrix 2 , an electrically conductive layer 3 , an adhesion promoter layer 4 , a release layer 5 , a protective lacquer layer 6 and a contact reinforcing layer 7 .

[0305] exist Figure 1d The membrane 1 shown in Figure 1c The film shown in FIG. 1 is different in that the protective lacquer layer 6 is Figure 1d In this way, Figure 1d The protective lacquer layer 6 shown in FIG. 1 has a layer thickness of 10 μm.

[0306] Figure 1eThe film 1 is shown, which comprises a carrier substrate 2 , a first electrically conductive layer 3 a , a protective lacquer layer 6 , a second electrically conductive layer 3 b , an adhesion promoter layer 4 , a release layer 5 and a contact strengthening layer 7 .

[0307] The first conductive layer 3a is shaped in such a way that the first conductive layer 3a has a large number of conductor lines, which extend in the y direction and are formed in a strip shape. The second conductive layer 3b is shaped in such a way that the second conductive layer 3b has a large number of conductor lines, which extend in the x direction and are also formed in a strip shape. The conductor lines of the first conductive layer 3a can be formed as sensor conductor lines here and the conductor lines of the second conductive layer can be formed as driver conductor lines, wherein the first conductive layer 3a and the second conductive layer 3b are electrically insulated from each other by the protective lacquer layer 6. In addition, it is possible that the conductor lines of the first conductive layer 3a and the second layer are shaped in a rhombus. In addition, it is possible that the conductor lines of the first conductive layer 3a form the y sensor of the touch sensor and the conductor lines of the second conductive layer 3b form the x sensor of the touch sensor. It is also possible that the conductor lines of the first conductive layer and the conductor lines of the second conductive layer are shaped differently, especially the conductor lines have different widths and / or different distances. For other designs of the conductor lines, please refer to the above embodiments.

[0308] As in Figure 1e , the film 1 has an adhesion promoter layer 4 in region 22 and no adhesion promoter layer in region 23. In the contacting region 20, a release layer 5 is also applied to the contact reinforcing layer 7, wherein the release layer covers the contacting region 20 over its entire surface. After application to the target substrate, the film 1 adheres to the target substrate in region 22, and in region 23 with region 20, the film 1 does not adhere to the target substrate, so that the contacting region 20 is accessible.

[0309] about Figure 1e For the design of other layers, please refer to the above-mentioned embodiment.

[0310] Figure 1f The film 1 is shown, which comprises a carrier substrate 2 , a first electrically conductive layer 3 a , a dielectric layer 8 , a second electrically conductive layer 3 b , a protective lacquer layer 6 , an adhesion promoter layer 4 , a release layer 5 and a contact strengthening layer 7 .

[0311] About Figure 1f The design of the layers 2, 3a, 3b, 4, 5, 6 and 7 in the embodiment of the present invention is referred to above. Figure 1f As shown in FIG, a dielectric layer 8 is arranged between the first conductive layer 3a and the second conductive layer 3b. The dielectric layer is preferably a layer of PE, PTFE or ceramic having a layer thickness between 0.1 μm and 100 μm, preferably between 0.25 μm and 25 μm, and more preferably between 0.5 μm and 10 μm. Figure 1fThe dielectric layer shown in is a layer of PE with a layer thickness of 6 μm. It is also possible that the layer 8 is a semiconducting or insulating layer.

[0312] As in Figure 1f As shown in FIG, the film 1 has an adhesion promoter layer 4 in the region 22 and no adhesion promoter layer in the region 23. Figure 1f As shown in FIG, there is a release layer 5 not only in the contact area 20 but also in the area 24 adjacent to the contact area 20. The release layer is applied over the entire surface in the areas 20 and 24. After being applied to the target substrate, the film 1 is attached to the target substrate in the area 22, and in the area 23 with the areas 20 and 24, the film 1 is not attached to the target substrate, so that the contact area 20 is accessible. In addition, the film 1 can be lifted in the area 23 after being applied to the target substrate, so that reliable and stable contact can be made. The area 24 can act as a movable hinge here to lift the contact area 20.

[0313] Figure 2a and Figure 2b A further embodiment variant of a membrane 1 according to the invention is shown, which comprises a carrier matrix 2 , an electrically conductive layer 3 and an adhesion promoter layer 4 .

[0314] The surface undulation structure is shaped Figure 2a The conductive layer 3 is shown in FIG. Figure 2a In the embodiment, a metal layer, for example aluminum, is first applied locally to the carrier substrate 2 over the entire surface. The surface relief structure of the metal layer 3 can then be produced by etching the metal with acid, by laser structuring the surface or by mechanical surface treatment. The aforementioned laser structuring of the surface is carried out, for example, by removing, in particular ablating, the metal on the surface of the metal layer with the help of a solid-state laser, such as an Nd:YAG laser. The above-mentioned mechanical surface treatment is preferably a mechanical roughening method such as friction, sanding, brushing or similar. Such a surface treatment of the metal layer can be carried out over the entire metal layer 3 or only locally. Figure 2a In the embodiment, the metal layer 3 has a surface relief structure in the entire functional area 21, but does not have a surface relief structure in the contact connection area 20. After the surface treatment, the metal layer 3 is structured to produce a conductor track. The metal layer 3 can be structured, that is, locally removed, for example, by a metal removal method, such as etching or washing, to produce a conductor track.

[0315] As in Figure 2a, the adhesion promoter layer 4 is present in region 22 and absent in region 23, so that after application to the target substrate, the film 1 adheres to the target substrate in region 22 and does not adhere to the target substrate in region 23 with the contact region 20. The contact region 20 is therefore accessible after application to the target substrate.

[0316] about Figure 2a For other designs of the middle layers 3 and 4 or the design of the layer 2 , reference is made here to the above-described embodiments.

[0317] exist Figure 2b The film 1 shown in FIG. Figure 2a The film 1 shown in FIG. 1 is different in that the conductive layer 3 does not have a surface relief structure, but a darkening layer 9 is applied to the conductive layer 3. The darkening layer 9 is preferably a layer with a dark color, which absorbs light incident on the darkening layer 9. The darkening layer 9 can be applied here by means of conventional coating methods, such as printing, doctor blade or projection. The conductive layer 3 and the carrier matrix 2 can also have different wettabilities, for example, so that the wettability of the colored paint providing the darkening layer 9 is selected so that it only adheres well to the conductor line formed by the conductive layer 3. The darkening layer 9 can also be selectively applied to the conductor line by means of a thermal transfer method. In this way, the conductor line can be selectively heated by a lamp, wherein the molten colored material is preferably deposited on the heated conductor line. However, it is also possible that the layer 9 is a layer with light scattering properties. For this reason, the layer with light scattering properties preferably has a surface relief structure, especially a matte structure with randomly selected relief parameters. However, it is also possible that the layer 9 is a layer with a surface relief structure that absorbs light, such as a moth-eye structure.

[0318] Figure 3 The film 1 is shown, which comprises a carrier substrate 2 , a conductive layer 3 , an intermediate adhesive layer 11 , decorative layers 12 a and 12 b , an adhesion promoter layer 4 , a release layer 5 and a contact reinforcement layer 7 .

[0319] As in Figure 3 As shown in FIG, the intermediate adhesive layer 11 is arranged on the side of the conductive layer facing away from the carrier substrate 2. In addition, the intermediate adhesive layer 11 covers the functional area 21 formed by the conductive layer 3, but does not cover the contact area 20. In addition, the intermediate adhesive layer 11 is arranged between the conductive layer and the first decorative layer 12a.

[0320] The intermediate adhesive layer 11 is preferably an adhesive layer composed of a primer layer and / or a hot melt adhesive, a cold adhesive or a radiation-curable adhesive, in particular an adhesive that can be cured by electromagnetic radiation and / or electron radiation. It is also possible that the intermediate adhesive layer 11 has PMMA, polyester, PU or PVC. The intermediate adhesive layer 11 is preferably applied by gravure printing, screen printing, relief printing or casting technology with a layer thickness between 0.1 μm and 50 μm, preferably between 0.25 μm and 25 μm, and further preferably between 0.5 μm and 7 μm. Figure 3 The intermediate adhesive layer 11 shown in FIG. 1 is a hot melt adhesive layer with a layer thickness of 5 μm.

[0321] As in Figure 3 As shown in FIG. 2 , the decorative layers 12a and 12b are arranged in the same region 22 as the adhesion promoter layer 4, so that when viewed perpendicularly to the plane defined by the carrier substrate 2, the decorative layers 12a and 12b are arranged congruently overlapping the adhesion promoter layer 4 and / or the intermediate adhesive layer 11. This ensures that, despite the presence of the additional decorative layers 12a and 12b, the contacting region is accessible for reliable and stable contacting of the electrical functional structure.

[0322] exist Figure 3 The decorative layer 12a shown in is preferably a replication lacquer layer. The replication lacquer layer is made, for example, of a thermoplastic lacquer into which a surface relief structure is at least partially replicated by means of heat and pressure through the action of an embossing tool. It is also possible that the replication lacquer layer is formed from a UV-crosslinkable lacquer and that the surface relief structure is replicated into the replication lacquer layer by means of UV rays. In this case, the surface relief structure is replicated into the unhardened replication lacquer layer by the action of an embossing tool and the replication lacquer layer is hardened directly during or after the replication by irradiation with UV rays. It is also advantageous if the replication lacquer layer has a layer thickness of between 0.2 μm and 4 μm, preferably between 0.3 μm and 2 μm, further preferably between 0.4 μm and 1.5 μm. Figure 3 The decorative layer 12 a shown in FIG. 1 is a replication lacquer layer of a UV-crosslinkable lacquer with a layer thickness of 1.25 μm.

[0323] exist Figure 3The decorative layer 12b shown in is preferably a reflective layer. The reflective layer is preferably a metal layer composed of chromium, aluminum, gold, copper, silver or an alloy of such metals, which is evaporated in a vacuum with a layer thickness of 0.01 μm to 0.15 μm. It is also possible that the reflective layer is formed by a transparent reflective layer, preferably a thin or finely structured metal layer or by an HRI or LRI dielectric layer (English, high refraction index -HRI, low refraction index -LRI). Such a dielectric reflective layer is made, for example, of a evaporated layer with a thickness of 10 nm to 150 nm and composed of metal oxides, metal sulfides, such as titanium dioxide, etc. It is also possible that the reflective layer is only implemented locally. In this way, it is possible that there is a partial metallization, which, for example, forms a metallic text or a nanotext. In Figure 3 The decorative layer 12 b shown in FIG. 1 is a metal layer of copper with a layer thickness of 10 nm.

[0324] about Figure 3 For the design of other layers, please refer to the above-mentioned embodiment.

[0325] Figure 4a The film 1 is shown, which comprises a carrier substrate 2 , a conductive layer 3 , an intermediate adhesive layer 11 , a decorative layer 12 c , an adhesion promoter layer 4 and a contact reinforcing layer 7 .

[0326] As in Figure 4a As shown in FIG. , the adhesion promoter layer 4 is arranged on that side of the carrier substrate 2 which faces away from the electrically conductive layer.

[0327] Furthermore, the adhesion promoter layer 4 is applied over the entire surface when viewed perpendicularly to the plane defined by the carrier substrate 2. However, it is also possible that no adhesion promoter layer 4 is provided in the region 23a overlapping the contact-making region 20 of the conductive layer 3. Figure 4a 4a and 4b. This allows the adhesion of the film 1 to the target substrate to be optimized. Layer 4a can be used for material optimization of the carrier substrate 2 and layer 4b for material optimization of the target substrate, to which the film 1 should be applied with the aid of the adhesion promoter layer 4.

[0328] As in Figure 4a As shown in FIG, the intermediate adhesive layer 11 is arranged on the side of the conductive layer 3 facing away from the carrier substrate 2. In addition, the intermediate adhesive layer 11 covers the functional area 21 formed by the conductive layer 3, but does not cover the contact area 20. In addition, the intermediate adhesive layer 11 is arranged between the conductive layer t and the first decorative layer 12c.

[0329] As in Figure 4aAs shown in FIG. 2 , the decorative layer 12 c is arranged in the same region as the intermediate adhesive layer 11 , so that the decorative layer 12 c is arranged congruently with the intermediate adhesive layer 11 when viewed perpendicularly to a plane defined by the carrier substrate 2 .

[0330] In particular, it is thereby achieved that despite the presence of the additional decorative layer 12 c , the contact region 20 can be contacted reliably and securely.

[0331] The decorative layer 12c is preferably a transparent colored lacquer layer. For this purpose, the decorative layer 12c contains pigments and / or pigments, which give the decorative layer 12c, for example, a color filter effect.

[0332] The decorative layer 12c preferably forms a pattern. The pattern can be, for example, a graphic outline, a figurative representation, an image, a theme, a symbol, a logo, a portrait, an alphanumeric symbol, a text and the like. It is also possible that the pattern has differently colored pattern elements.

[0333] However, it is also possible that the decorative layer 12c is a printed layer, in particular composed of an opaque and / or colored ink. The printed layer can, for example, form a frame around the functional area 21 or can be printed in a pattern, for example in a linear manner.

[0334] About Figure 4a For the design of other layers, please refer to the above-mentioned embodiment.

[0335] Figure 4b The film 1 is shown, which comprises a carrier substrate 2 , a conductive layer 3 , an intermediate adhesive layer 11 , decorative layers 12 c and 12 d , an adhesion promoter layer 4 and a contact reinforcing layer 7 .

[0336] The decorative layer 12d is preferably a transparent carrier layer made of PET, PMMA, PC, ABS, PU, ​​glass, fabric or a hybrid material having a plastic layer and a layer of fabric, in particular a fiber material, such as paper, cotton or other natural or artificial fibers. The carrier layer preferably has a layer thickness of between 2 μm and 250 μm, preferably between 23 μm and 125 μm. Figure 4b The decorative layer 12d shown in FIG. 1 is a transparent layer of PET with a layer thickness of 25 μm. Figure 4b As shown in FIG. 1 , the decorative layer 12 d is also arranged congruently with the intermediate adhesive layer 11 , so that the contact-making region remains accessible and electrical functional structures can be contacted reliably and securely.

[0337] about Figure 4b For the design of other layers, please refer to the above-mentioned embodiment.

[0338] Figure 4cA film 1 is shown which comprises a carrier substrate 2 , a conductive layer 3 , an intermediate adhesive layer 11 , decorative layers 12 c , 12 d and 12 e , an adhesion promoter layer 4 and a contact reinforcing layer 7 .

[0339] The decorative layer 12e is preferably a transparent colored lacquer layer. For this purpose, the decorative layer 12e contains pigments and / or pigments, which give the decorative layer 12e, for example, a color filter effect. If, for example, the decorative layer 12c is also formed as a transparent colored lacquer layer, as explained above, a color filter effect, in particular a color mixing effect, is produced for the observer through the interaction of the two decorative layers 12c and 12e. However, it is also possible, for example, that the decorative layer 12c and the decorative layer 12e are printed layers, which each form a pattern. Here, the two decorative layers 12c and 12e can interact in such a way that a moiré effect is produced for the observer and a predetermined moiré pattern can be discerned. The decorative layer 12d can act here, for example, as a transparent spacer layer. As in Figure 4b As shown in FIG, the decorative layer 12 e is also arranged congruently with the intermediate adhesive layer 11 , so that the contact-making region remains accessible.

[0340] about Figure 4c For the design of other layers, please refer to the above-mentioned embodiment.

[0341] Figure 5a A film 1 is shown which comprises a carrier substrate 2 , a conductive layer 3 , an intermediate adhesive layer 11 , decorative layers 12 c , 12 d and 12 f , an adhesion promoter layer 4 and a contact reinforcing layer 7 .

[0342] As in Figure 5a As shown in , the bonding agent layer 4 can be applied over the entire surface. However, it is also possible that the bonding agent layer 4 is not present in the region 23a. This further improves the accessibility of the contact-making region, since the corresponding surface region 23a is freely exposed on both sides, which surface region can be particularly easily electrically contacted in the subsequent processing steps, for example by means of a plug connection.

[0343] The decorative layer 12f is preferably a partially printed optically transparent paint layer. The decorative layer 12f produces a tactile and / or tactile effect due to the surface relief structure. That is, the decorative layer 12f is tactile and / or tactile detectable. In addition, it is also possible that the surface relief structure of the decorative layer 12f produces a diffractive and / or refracting visual effect. It is also possible that the surface relief structure is produced by mechanical structuring or optical structuring of the layer surface, especially by means of a laser. Mechanical structuring can be a replication using a correspondingly shaped embossing tool. Optical structuring can be laser ablation. In addition, photolithography methods can also be used to produce structures. The structural depth of the tactile and / or tactile perceptible surface relief structure is preferably between 1μm and 2000μm, and further preferably between 50μm and 2000μm. The structural depth for the diffraction or refraction effect is preferably between 0.1μm and 20μm, and further preferably between 0.1μm and 5μm.

[0344] As in Figure 5a As shown in FIG. 1 , the decorative layer 12 f is arranged on the decorative layer 12 d . Furthermore, the decorative layers 12 c , 12 d and 12 f are arranged on the same side of the carrier substrate 2 .

[0345] about Figure 5a For the design of other layers, please refer to the above-mentioned embodiment.

[0346] Figure 5b A film 1 is shown which comprises a carrier substrate 2 , a conductive layer 3 , an intermediate adhesive layer 11 , decorative layers 12 c , 12 d , 12 e and 12 f , an adhesion promoter layer 4 and a contact reinforcing layer 7 .

[0347] about Figure 5b The design of the middle layer here refers to the above-mentioned implementation method.

[0348] Figure 5c A film 1 is shown which comprises a carrier substrate 2 , a conductive layer 3 , an intermediate adhesive layer 11 , decorative layers 12 a , 12 b and 12 f , an adhesion promoter layer 4 , a release layer 5 and a contact strengthening layer 7 .

[0349] As in Figure 5c , the decorative layer 12f is arranged on the side of the carrier substrate 2 facing away from the conductive layer 3. The decorative layers 12a and 12b are, in contrast, arranged on the side of the carrier substrate 2 facing the conductive layer 3 or on the side of the conductive layer 3 facing away from the carrier substrate 2.

[0350] About Figure 5c The design of the middle layer here refers to the above-mentioned implementation method.

[0351] Figure 6aA film 1 is shown which comprises a carrier substrate 2 , a conductive layer 3 , an intermediate adhesive layer 11 , decorative layers 12 d , 12 g , 12 h and 12 i , an adhesion promoter layer 4 and a contact reinforcing layer 7 .

[0352] As in Figure 6a As shown in the figure, the decorative layers 12d, 12g, 12h and 12i are arranged in the same region as the intermediate adhesive layer 11, so that when viewed perpendicularly to the plane defined by the carrier substrate 2, the decorative layers 12d, 12g, 12h and 12i are arranged to be congruently overlapped with the intermediate adhesive layer 11. In particular, this makes it possible to reliably and securely contact the contact region 20 despite the presence of the additional decorative layers 12d, 12g, 12h and 12i.

[0353] The decorative layers 12g, 12h and 12i here form, for example, a thin-film layer system. The decorative layer 12g is a semi-transparent reflective layer, preferably a very thin and thereby semi-transparent metal layer, for example a layer of chromium with a layer thickness of 5 nm. The decorative layer 12h is a spacer layer, which is preferably made of a transparent dielectric, for example MgF2, SiO2 or a polymer. The layer thickness of the spacer layer is preferably selected here so that for a certain viewing angle for λ in the wavelength range of visible light, the condition that the layer thickness is equal to λ / 2 or λ / 4 is met, that is, the optical thickness of the decorative layer 12h is in the range of half or a quarter of the wavelength of the light and thereby generates a viewing angle-dependent color shift effect in the range of light visible to the human eye when light reflected back from the interface between the decorative layer 12g and the spacer layer 12h on the one hand and the interface between the spacer layer 12h and the decorative layer 12i on the other hand interferes. The decorative layer 12i is a metallic reflective layer, preferably an opaque metal layer, for example a layer of aluminum with a layer thickness of 30 nm.

[0354] about Figure 6a For the design of other layers, please refer to the above-mentioned embodiment.

[0355] Figure 6b and Figure 6c Film 1 including carrier substrate 2 , conductive layer 3 , intermediate adhesive layer 11 , decorative layers 12 d , 12 j , and 12 h , adhesion promoter layer 4 , and contact reinforcement layer 7 are shown respectively.

[0356] The decorative layer 12h is a transparent layer, which acts as a spacer layer. The spacer layer 12h creates a visual three-dimensional effect. Figure 6b and Figure 6cAs shown in , the decorative layer 12h can be arranged behind and / or in front of the decorative layer 12j in the viewing direction. However, it is also possible that the decorative layer 12h is arranged, for example, between two decorative layers. The optically transparent layer 12h has a layer thickness, which is a multiple of the layer thickness of the decorative layer 12j. However, it is also possible that the layer thickness of the decorative layer 12h is substantially equal to the layer thickness of the decorative layer 12j. Preferably, the layer thickness of the optically transparent layer 12h is between 0.5μm and 500μm, further preferably between 10μm and 100μm. The optically transparent layer 12h is composed, for example, of an optically transparent paint and / or an optically transparent film, in particular a film made of PET, PMMA or PC.

[0357] The decorative layer 12j can be, for example, a metallic layer, for example an aluminum layer with a layer thickness of 20 nm. Advantageously, the decorative layer 12j is realized in regions and forms a pattern.

[0358] about Figure 6b and Figure 6c For the design of other layers, please refer to the above-mentioned embodiment.

[0359] Figure 7 The film 1 is shown, which comprises a carrier substrate 2 , a separating layer 13 , a protective lacquer layer 6 , an electrically conductive layer 3 , an intermediate adhesive layer 11 , a release layer 5 , decorative layers 12 a and 12 b , an adhesion promoter layer 4 and a contact reinforcing layer 7 .

[0360] The separation layer 13 is preferably a wax layer and / or a polymer layer composed of a lacquer crosslinked with, for example, acrylates and / or melamine formaldehyde resins. Preferably, the separation layer 13 has a layer thickness of less than 1 μm. Figure 7 The separation layer 13 shown in FIG. 1 is a wax layer with a layer thickness of 0.5 μm.

[0361] It is possible that the film 1 is a transfer film having a carrier layer, in particular a carrier matrix 2, and a transfer layer 70 that can be peeled off from the carrier layer, in particular the carrier matrix 2. Advantageously, a separating layer 13 is arranged between the carrier layer, in particular the carrier matrix 2, and the transfer layer 70, which allows the transfer layer 70 to be peeled off from the carrier layer, in particular the carrier matrix 2. It is thus possible to apply only the transfer layer 70 to the target substrate, in particular by means of hot embossing. Figure 7 In the embodiment, the transfer layer 70 is composed of a separation layer 13, a protective lacquer layer 6, a conductive layer 3, an intermediate adhesive layer 11, a release layer 5, decorative layers 12a and 12b, an adhesion promoter layer 4 and a contact strengthening layer 7. The separation layer 13 can be removed after applying the transfer layer of the film 1 to the target substrate.

[0362] Furthermore, it is possible that the separating layer 13 is a one-layer or multi-layer separating layer. Preferably, the separating layer 13 is arranged between the carrier substrate 2 and the protective lacquer layer 6 .

[0363] It is thus possible that after the film 1 has been applied to the target substrate and after the carrier substrate 2 and the separating layer 13 have been removed, the protective lacquer layer 6 forms the outermost layer and protects the electrically conductive layer 3 from environmental influences. It can also be achieved that the carrier substrate 2 can be peeled off after the film 1 has been applied to the target substrate. This can achieve even better deformability and / or stretchability of the applied film, since the relatively thick and less deformable and / or less stretchable carrier substrate 2 has been removed. The protective lacquer layer 6 assumes the function of protecting the film 1.

[0364] about Figure 7 For the design of other layers, please refer to the above-mentioned embodiment.

[0365] Figure 8 The film 1 is shown including a carrier substrate 2 , a separating layer 13 , a protective lacquer layer 6 , a primer layer 14 , a conductive layer 3 , an intermediate adhesive layer 11 , a release layer 5 , decorative layers 12 a and 12 b , an adhesion promoter layer 4 and a contact reinforcing layer 7 .

[0366] Advantageously, the primer layer 14 is a vapor-depositable primer layer for metallization, which is arranged in particular between the protective lacquer layer 6 and the electrically conductive layer 3 .

[0367] The primer layer 14 is preferably a layer of a polymer and / or copolymer, in particular comprising polymethyl (meth)acrylate (PMMA), polyester, polyurethane (PU) or polyvinyl chloride (PVC). Less preferably, the primer layer 14 comprises a natural resin, preferably rosin, phenolic resin, an isocyanate (NCO)-crosslinked binder, for example melamine-formaldehyde-condensation resin (MF), melamine-phenol-formaldehyde resin (MPF), melamine-polyester, melamine-urea-formaldehyde resin (UMF), poly(organo)siloxane or a radiation-curing binder.

[0368] Furthermore, the primer layer 14 preferably has a layer thickness of between 0.1 μm and 5 μm, further preferably between 0.1 μm and 2 μm.

[0369] exist Figure 8 The primer layer 14 shown in FIG. 1 is a layer of PMMA with a layer thickness of 1.5 μm.

[0370] Advantageously, it can be provided that the adhesion between the carrier substrate 2 and the protective lacquer layer 6 is 20% to 80%, preferably 30% to 70%, smaller than the adhesion between the protective lacquer layer 6 and the primer layer 14 and / or the at least one electrically conductive layer 3 and / or the adhesion promoter layer 4 due to the separating layer 13 provided between the carrier substrate 2 and the protective lacquer layer 6 .

[0371] Like this, it is possible that the adhesion between the carrier substrate 2 and the protective lacquer layer 6 is 20% to 80% less, preferably 30% to 70% less, than the adhesion 13 between the layers of the transfer layer due to the separation layer arranged between the carrier substrate 2 and the protective lacquer layer 6, which is especially selected from a group including a protective lacquer layer, a primer layer, at least one conductive layer, one or more decorative layers, an adhesion promoter layer, an intermediate adhesion layer, a dielectric layer, a darkening layer and a contact strengthening layer. The adhesion is determined by means of a tensile testing machine Zwick Z005 of Zwick GmbH & Co. KG of Ulm, Germany. For this purpose, the transfer film is flatly bonded to the support below. Then the layer to be peeled off is peeled off by a tensile test at right angles. The peeling force is determined by a dynamometer.

[0372] about Figure 7 For the design of other layers, please refer to the above-mentioned embodiment.

[0373] Fig. 9 A film 1 is shown which comprises a carrier substrate 2 , a conductive layer 3 , an intermediate adhesive layer 11 , decorative layers 12 a and 12 b , an adhesion promoter layer 4 and a contact reinforcing layer 7 .

[0374] As in Fig. 9 As shown in , the carrier film 2 ends flush with the other layers of the film 1 at both ends. Fig. 9 As shown in FIG. 2 , the adhesion promoter layer 4 is present in the region 22 and is absent in the region 20 .

[0375] Furthermore, it is possible to print the film 1 completely or partially in a pattern, for example in a grid, with an adhesive lacquer in the contact-making region 20 . In this way, the adhesive lacquer can be applied to the contact reinforcing layer 7 .

[0376] The adhesive lacquer is preferably an electrically conductive adhesive lacquer.

[0377] Alternatively, it is also possible that the film 1 does not have an adhesive lacquer in the contacting region 20. Therefore, after the film 1 is applied to the target substrate, an electrical (pressure) contact between the film 1 and the target substrate is produced (by heat and pressure), especially in the contacting region 20. It is possible here that the electrical (pressure) contact acts permanently via the adhesion, especially via the adhesive lacquer.

[0378] About Fig. 9 The design of the middle layer here refers to the above-mentioned implementation method.

[0379] Fig.10 The film 1 is shown, which comprises a carrier substrate 2 , a separating layer 13 , a protective lacquer layer 6 , an electrically conductive layer 3 , an intermediate adhesive layer 11 , decorative layers 12 a and 12 b , an adhesion promoter layer 4 and a contact reinforcing layer 7 .

[0380] exist Fig.10 The membrane 1 shown in FIG. 1 can also be Fig. 9 As shown in the film shown in FIG, the contact area 20 is completely or partially printed with adhesive lacquer in a pattern. Fig.10 As shown in , the carrier layer 2 protrudes beyond the other layers of the film on one side. This makes it possible to simply peel off the carrier film 2 after applying the film 1 to the target substrate. The separating layer 6 arranged between the carrier layer 2 and the protective lacquer layer 6 makes it possible to peel off the carrier layer 2.

[0381] About Fig.10 The design of the middle layer here refers to the above-mentioned implementation method.

[0382] Fig.11a A top view of conductor tracks 31, 32 is shown. The conductor tracks 31, 32 form a correspondingly shaped conductive layer 30 made of silver. The conductor tracks 31, 32 have a width 26 between 0.2 μm and 20 μm, preferably between 4 μm and 15 μm, and have a distance 27 from each other greater than 10 μm, preferably greater than 20 μm, so that the conductor tracks 31, 32 are below the resolution capability of the human eye. The conductor track 31a is formed by the first conductive layer and the conductor track 32a is formed by the second conductive layer. The conductor track 31a forms the driver conductor track here and the conductor track 32a forms the sensor conductor track. The driver conductor track is loaded with an alternating current, for example, by means of a driver circuit. The capacitance generated at the intersection of the conductor tracks 31a and 32a changes, for example, when a finger touches the film with the conductive layer 30. This is detected by the sensor conductor track 32a by means of a sensor circuit connected to the sensor conductor track 32a and the position of the touch or the capacitance change is determined.

[0383] Fig.11b Show Fig.11a An amplified local 30v. Fig.11b As shown in FIG, the conductor line 32 formed by the conductive layer forms three contact areas separated from each other. The three contact areas have a minimum distance of 0.5 mm from each other, for example, so as to achieve electrical insulation of the contact areas. A contact reinforcement layer 7 is applied to the conductor line 32. Fig.11b The contact strengthening layer 7 shown in FIG. 1 is a layer of carbon conductive paint with a layer thickness of 4.5 μm. Fig.11b The surface area occupied by the contact reinforcement layer 7 shown in FIG. has a size of 0.3 mm×2.0 mm. The surface area occupied by the contact reinforcement layer 7 protrudes at least partially beyond the conductor track 32 widened in the end area. As a result, the contact area formed by the conductor track 32 can be enlarged as long as the electrical connection between the contact area and the contact reinforcement layer 7 is ensured.

[0384] Fig.121 shows a top view of another design variant of the conductor tracks 31, 32. The conductor tracks 31, 32 are formed here by a correspondingly shaped conductive layer 30 made of silver. Fig.12 As shown in FIG. 1 , the conductor lines 31a of the first conductive layer and the conductor lines 32a of the second conductive layer are structured, in particular, structured so that the conductor lines 31a, 32a of the first conductive layer and the second conductive layer form a plurality of surface elements 33. The surface elements 33 are Fig.12 The first conductive layer and the second conductive layer are each formed in a rhombus or rhombus shape, so that the first conductive layer and the second conductive layer each have a so-called diamond structure. Fig.12 , the diamond structure is formed by a plurality of rhombus-shaped surface elements 33 along linear conductor paths 31, 32. Here, the first conductive layer and the second layer each have a plurality of diamond structures spaced apart from each other. The first conductive layer and the second layer are arranged one on top of the other in such a way that the two diamond structures are arranged at right angles, i.e., 90° relative to each other. Here, the surface elements 33 of the first conductive layer are arranged on the "gap" in the free gap between the surface elements 33 of the second conductive layer, wherein the linear conductor paths 31, 32 of the conductive layer cross in the gap between the surface elements. In this embodiment variant, the exact position of the surface elements 33 relative to each other is particularly important and the surface elements 33 are preferably arranged accurately relative to each other with a tolerance fit of less than 0.25 mm, preferably less than 0.1 mm.

[0385] As in Fig.12 As shown in , the conductor lines 31, 32 are shaped in the area of ​​the surface element 33 according to the shape of the surface element 33, so that the surface element is filled with the material of the conductive layer over its entire surface. It is also possible that the conductor lines extend only along the surface element, so that the surface element is only surrounded at least partially by the conductor lines. The conductor lines then extend, for example, partially straight and then extend triangularly in the area of ​​the surface element. In addition, the conductor lines 31, 32 are as shown in Fig.12 A conventional grid arrangement is shown in FIG. , wherein the conductive layer is at least semi-transparent due to the gridding.

[0386] Fig.13 The film 1 is shown, which comprises a first electrically conductive layer 3 a , a second electrically conductive layer 3 b , a carrier substrate 2 , a protective lacquer layer 6 , an adhesion promoter layer 4 , an intermediate adhesive layer 11 and a contact-making region 7 .

[0387] As in Fig.13 As shown in FIG, conductive layers 3a and 3b are provided on each carrier substrate 2. A protective lacquer layer 6 is applied locally to the second conductive layer 3b, but not to the contact-making areas. An intermediate adhesive layer 11 is applied locally to the first conductive layer 3a. The intermediate adhesive layer 11 covers the functional areas formed by the conductive layer 3, but not to the contact-making areas. As shown in FIG. Fig.13As shown in FIG, the carrier substrate 2 together with the second conductive layer 3b is applied to the first conductive layer 3a by means of an adhesion promoter layer 4 and an intermediate adhesive layer 11. The intermediate adhesive layer 11 can also be a protective lacquer layer, so that the first conductive layer and the second layer 3a and 3b are arranged one on top of the other only via the adhesion promoter layer 4. The conductive layers 3a and 3b are arranged on Fig.13 The first conductive layer 3a and the second conductive layer 3b are preferably positioned with precise fit relative to one another, in particular with a tolerance of less than 0.25 mm, preferably with a tolerance of less than 0.1 mm. Preferably, the conductive layers 3a, 3b have conductor tracks, as already explained, which are arranged in a grid. The grid can be regular or irregular. The grid can be composed in particular of grid elements, such as line and / or surface elements. The grid elements can form so-called sensor rows.

[0388] about Fig.13 For the design of other layers, please refer to the above-mentioned embodiment.

[0389] Fig.14 3a is a first conductive layer, which can be contacted in the contact area 20a. 3b is a second conductive layer, which can be contacted in the contact area 20b. The conductive layers 3a, 3b can be, for example, Fig.13 , respectively arranged on the carrier substrate 2. If the two conductive layers 3a and 3b are now arranged one above the other, as shown in the top view in 3a, b, the two contact areas 20a, 20b are now arranged side by side and thus form a common contact area 20c. With regard to the overlapping arrangement of the conductive layers 3a and 3b, reference is made to the above-mentioned embodiments. The common contact area 20c is electrically contacted, for example, by means of an adapter element 51. The adapter element 51 is preferably a flexible adapter element 51, which electrically contacts the contact points in the common contact area 20c and is electrically conductively connected to another contact element 52 on the outside. The contact between the common contact area 20c and the adapter element 51 is preferably carried out by means of a connecting element 50 composed of an electrically conductive adhesive, in particular by means of an ACF bond (ACF = anisotropic conductive film). The other contact element 52 can be, for example, a standardized plug connector, such as a ZIF connector (ZIF = no insertion force).

[0390] Fig.15a and Fig.15b The method steps for producing an electrical functional element are shown. Fig.15a The use of the film 1 according to the invention is shown for application to a target substrate 10. The target substrate 10 can be, for example, a display. With regard to the design of the layers of the film 1, reference is made to the above-described embodiments. Fig.15aAs shown in FIG, the film does not have an adhesion promoter layer 4 in region 23. Region 23 thus forms a tail region in which the contact-making region 20 is located. Fig.15b As shown in FIG. 1 , the film 1 is applied to a target substrate 10, thereby forming an electrical functional element. If, for example, the electrical functional structure forms a touch sensor area, in particular a capacitive sensor area providing a touch area function, and the target substrate is a display, a touch screen can be produced, for example. Fig.15a In the unapplied state shown in FIG. 1 , it is possible that the adhesion promoter layer 4 has a cloudy visual appearance, for example due to the surface roughness of the adhesion promoter layer 4 . After applying the film 1 to the target substrate 10 , as in Fig.15b As shown in , the adhesion promoter layer 4 is now preferably highly transparent and clear, because for example the surface roughness of the adhesion promoter layer 4 is leveled by the application process. The application of the film 1 can be carried out by hot lamination. In addition, it is possible that the film 1 from the roll is applied to the target substrate 10 by means of hot lamination. The film web speed is preferably between 1.5m / min and 3.5m / min here. Preferably, hot lamination is carried out at a temperature in the range between 80°C and 300°C, preferably between 200°C and 290°C, further preferably between 240°C and 270°C, and / or with an embossing pressure in the range between 200 bar and 2000 bar, preferably between 500 bar and 1500 bar.

[0391] exist Fig.15b The electrical functional element shown in the figure can be lifted in the tail area 23, so that the contact area 20 is reliably accessible and can be reliably contacted in other steps. In the area 22 with the adhesion promoter layer 4, the film 1 is attached to the target substrate 10. In the area 22, the adhesion of the film 1 is at least so strong that the film 1 will not be detached from the target substrate 10 during normal use. For example, the adhesion is tesa firm, that is to say, the adhesion is so great that the adhesive tape tesa 4104 fixed on the film 1 by the 90° pulling method cannot be removed from the target substrate 10. The layers 2, 3, 6 and 4 of the film 1 are transparently implemented, so that the target substrate 10 is well visible to human observers through the film 1. If the target substrate 10 is, for example, a thin glass layer or a transparent layer of PMMA, the electrical functional element formed by the film 1 and the thin glass layer or PMMA layer is generally transparent. An electrical functional element composed of the film 1 and the PMMA layer can thus have a transmittance of 84.6% for light in the wavelength range between 300 nm and 800 nm, preferably between 380 nm and 780 nm, wherein the PMMA layer alone has a transmittance of 93.6%.

[0392] Fig.16a and Fig.16bThe method steps for producing an electrical functional element are shown. Fig.16a and Fig.16b Corresponds to Fig.15a and Fig.15b , the difference is that the film 1 additionally has a release layer 5. The release layer 5 ensures that the film 1 does not adhere to the target substrate 10 in the area 23. For the design of the release layer 5, refer to the above-mentioned embodiment. Fig.16b The membrane 1 shown in FIG. 1 can thus also be used as in Fig.15b In the region 23 with the contact-making region 20 , the film 1 is lifted, as shown in FIG. 2 . In the region 22 , on the other hand, the film 1 adheres to the target substrate 10 .

[0393] Fig.17a and Fig.17b The method steps for producing an electrical functional element are shown. Fig.17a and Fig.17b Corresponds to Fig.15a and Fig.15b , the difference is that the film 1 additionally has a peeling layer 5, an intermediate adhesive layer 11 and decorative layers 12a and 12b. For the design of the layers 5, 11, 12a and 12b, refer to the above-mentioned embodiment. Fig.17b The membrane 1 shown in FIG. 1 can thus also be used as in Fig.15b In the region 23 with the contact-making region 20 , the film 1 is lifted, as shown in FIG. 2 . In the region 22 , on the other hand, the film 1 adheres to the target substrate 10 .

[0394] Fig.18a and Fig.18b The method steps for producing an electrical functional element are shown. Fig.18a The use of the film 1 according to the invention is shown for application to a target substrate 10. With regard to the design of the layers of the film 1, reference is made to the above-described embodiments. Fig.18a As shown in FIG, the film 1 has an adhesion promoter layer 4 over the entire surface, but no intermediate adhesive layer 11 and decorative layer 12c are applied in the contact-making area. However, it is also possible that the adhesion promoter layer 4 is not present in the area 23a, so that the contact-making area can be lifted off the target substrate 10, for example, to further facilitate contact-making. As shown in FIG. Fig.18b As shown in FIG. 1 , the film 1 is applied to a target substrate 10, thereby forming an electrically functional element. Fig.18a In the unapplied state shown in FIG. 1 , it is possible that the adhesion promoter layer 4 has a cloudy visual appearance, for example due to the surface roughness of the adhesion promoter layer 4 . After applying the film 1 to the target substrate 10 , as in Fig.18bAs shown in , the adhesion promoter layer 4 is now preferably highly transparent and clear, because, for example, the surface roughness of the adhesion promoter layer 4 is smoothed by the application process. The film 1 can be applied by hot lamination as already explained. It is also possible that, as an alternative to hot lamination, the film 1 is applied to the target substrate 10 by spraying in an injection molding material, wherein the injection molding material in particular forms the target substrate 10. In this way, it is possible that the film 1 is fixedly connected to the injection molding material via the adhesion promoter layer 4.

[0395] According to the design of target matrix 10, for example, it is possible that the electric function element formed by film 1 and target matrix 10 is a mobile phone, for example a smart phone or PDA, tablet computer, automatic teller machine, automatic ticket machine, arcade machine, game machine, household appliance or operating part of motor vehicle or for example touch screen. It is also possible that the electric function element is an input device, especially touch pad. It is also possible that the electric function element formed by film 1 and target matrix 10 is a semi-finished product, which is installed as finished product or installed in the finished product in other processing steps. Aforesaid electric function element is preferably used for information processing, wherein for example, detects described information in the form of contact position by the electric function structure consisting of touch sensor area.

[0396] Fig.19a and Fig.19b The method steps for producing an electrical functional element are shown. Fig.19a The use of the film 1 according to the invention is shown for application to a target substrate 10. With regard to the design of the layers of the film 1, reference is made here to the above-described embodiments. Fig.19a As shown in FIG, the film 1 has no adhesion promoter layer 4 in the region 23. The region 23 thus forms the tail region in which the contact-making region 20 is located. Fig.19b As shown in FIG. 1 , the film 1 is applied to a target substrate 10, thereby forming an electrical functional element. Fig.19a In the unapplied state shown in FIG. 1 , it is possible that the adhesion promoter layer 4 has a cloudy visual appearance, for example due to the surface roughness of the adhesion promoter layer 4 . After applying the film 1 to the target substrate 10 , as in Fig.19b As shown in , the adhesion promoter layer 4 is now preferably highly transparent and clear, because, for example, the surface roughness of the adhesion promoter layer 4 is smoothed by the application process. The film 1 can be applied by hot embossing. It is possible here that the film from a roll or a printed sheet or a sheet is applied to the target substrate by means of hot embossing. Preferably, the hot embossing is carried out at an embossing temperature between 80° C. and 250° C., preferably between 100° C. and 200° C., and / or at a pressure of 0.5 kN / cm 2 Up to 10kN / cm 2 In addition, it is also suitable that the stamping time is in the range of 1 ms to 2000 ms, preferably in the range of 1 ms and 500 ms. After applying the film 1 to the target substrate, as in Fig.19b , the carrier substrate 2 is removed. As described above, the carrier substrate 2 can be peeled off because the adhesion between the carrier substrate 2 and the protective lacquer layer 6 is 20% to 80%, preferably 30% to 70% smaller than the adhesion 13 between the protective lacquer layer 6 and other applied layers of the film, in particular the conductive layer 3 of the intermediate adhesive layer 11 and / or the decorative layers 12a and 12b and / or the adhesion promoter layer 4, due to the separation layer provided between the carrier substrate 2 and the protective lacquer layer 6. Preferably, the adhesion between the carrier substrate 2 and the protective lacquer layer 6 is also smaller than the adhesion between the applied layers of the film, in particular the conductive layer 3 of the intermediate adhesive layer 11 and / or the decorative layers 12a and 12b and / or the adhesion promoter layer 4, and the target substrate 10, due to the separation layer 13 provided between the carrier substrate 2 and the protective lacquer layer 6, so that when the carrier substrate 2 is peeled off, the applied layers of the film 1 are not detached from the target substrate 10.

[0397] exist Fig.19b The electrical functional element shown in the figure can be lifted in the tail region 23, so that the contacting region 20 can be reliably approached and can be reliably contacted in further steps. In the region 22 with the adhesion promoter layer 4, the film 1 adheres to the target substrate 10. In the region 22, the adhesion of the film 1 is at least so strong that the film 1 will not detach from the target substrate 10 during normal use.

[0398] Fig.20a and Fig.20b The method steps for producing an electrical functional element are shown. Fig.20a and Fig.20b Corresponds to Fig.19a and Fig.19b , the difference is that the film 1 additionally has a primer layer 14. Regarding the design of the layer, reference is made to the above-mentioned embodiment. In addition, as in Fig.20b As shown in FIG, the carrier substrate 2 is not removed after applying the film 1 to the target substrate. Fig.20b The membrane 1 shown in FIG. 1 can thus also be used as in Fig.19b In the region 23 with the contact-making region 20 , the film 1 is lifted, as shown in FIG. 2 . In the region 22 , on the other hand, the film 1 adheres to the target substrate 10 .

[0399] Fig.21a and Figure 21b The method steps for producing an electrical functional element are shown. Fig.21a The use of the film 1 according to the invention is shown for application to a target substrate 10. With regard to the design of the layers of the film 1, reference is made to the above-described embodiments. Fig.21a As shown in FIG. 2 , the film 1 has no adhesion promoter layer 4 in the region 20 .

[0400] As in Fig.21aAs shown in the figure, the target substrate 10 has a contact layer 15, in particular, the at least one contact area 20 for the electrical contact film 1. Preferably, the contact layer 15 is applied directly to the target substrate 10. In addition, it is possible that the contact layer 15 has at least one connecting element, in particular an electrical connector, such as a plug. It is also possible that the contact layer 15 has at least one adapter element and / or contact element. That is to say, the target substrate 10 preferably already has a contact structure in the form of a contact layer 15, in particular, the at least one contact area 20 for the electrical contact film 1.

[0401] As in Fig.21a As shown in FIG. 1 , the contact layer 15 is arranged in the region 20. The region 20 thus constitutes a target contact area, which forms a mating part of the contact area 20 of the membrane 1. The target contact area of ​​the target substrate 10 and the contact area 20 of the membrane 1 are as shown in FIG. Fig.21a As shown in FIG. 1 , in particular, they overlap congruently after application of the film 1 to the target substrate 10. Furthermore, it is also possible that the target contacting region 20 of the target substrate 10 and the contacting region 20 of the film 1 overlap at least in places after application of the film 1.

[0402] In addition, the target matrix 10 is as Fig.21a The conductive layer 3c shown in FIG. 3 has a plurality of conductor lines, which are preferably arranged in a grid. The grid can be regular or irregular. The grid can be constructed in particular from grid elements, such as line and / or surface elements.

[0403] Furthermore, it is also possible for the electrically conductive layer 3 c to have other electrical components, such as antennas, capacitors and inductors.

[0404] As in Fig.21a As shown in FIG, the conductive layer 3c is electrically connected, in particular galvanically connected, to the contact layer 15. It is also possible that the conductive layer 3c is connected to the contact layer 15 via capacitive and / or inductive coupling.

[0405] The contact layer 15 and / or the conductive layer 3c are Fig.21a Preferably, the contact layer 15 and / or the electrically conductive layer 3 c are applied to the target substrate 10 by means of printing, in particular by means of screen printing. Furthermore, it is also possible to produce the contact layer 15 and / or the electrically conductive layer 3 c on the target substrate 10 by means of laser direct structuring (LDS).

[0406] The contact layer 15 is preferably made of an electrically conductive paste, in particular a carbon paste, which preferably contains silver (Ag), gold (Au), aluminum (Al), copper (Cu), chromium (Cr) and / or other electrically conductive metals. It is also possible that the electrically conductive paste, in particular a carbon paste, has a binder, which in particular has rosin and / or phenolic resin, polymers and copolymers. The binder of the electrically conductive paste, in particular the carbon paste, is a natural resin, preferably rosin, phenolic resin, polymers and copolymers made of PVC, PMMA, PU, ​​polyester, isocyanate (NCO) crosslinked binder, for example MF, MPF, melamine polyester, UMF.

[0407] Less preferred are electrically conductive pastes having binders of poly(organo)siloxanes and copolymers thereof and / or radiation-curing binders.

[0408] As in Figure 21b As shown in FIG. 1 , the film 1 is applied to a target substrate 10 , wherein the target substrate 10 has a contact layer 10 and a conductive layer 3 c as described above.

[0409] By applying the film 1 to the target substrate 10, the conductive layer 3c of the target substrate 10 is electrically connected to the functional structure of the conductive layer 3 of the film 1 via the contact area 20 of the film 1 by means of the contact layer 15. That is, the contact layer 15 on the target substrate 10 forms the mating contact of the contact area 20 of the film 1.

[0410] It is also possible that the film 1 is completely or partially patterned, for example in a grid, with adhesive lacquer. Preferably, when the film 1 is applied to a target substrate 10 provided with a contact layer 15, an electrical (pressure) contact (by heat and pressure) between the film 1 and the target substrate 10 is produced, in particular in the at least one contact region 20 and / or the target contact region. It is thus possible to produce an electrical contact between the contact layer 15 of the target substrate 10 and the contact region 20 of the film 1. The electrical (pressure) contact is permanently reinforced by the adhesive portion, in particular by the adhesive lacquer. The adhesive lacquer is advantageously an electrically conductive adhesive lacquer.

[0411] Furthermore, it is possible to introduce an ACF bonding tape between the contact-making region 20 of the film 1 and the target contact-making region of the target substrate 10. This can further improve the electrical connection in the contact-making region 20. It is advantageous here that the application process (heat and pressure) also corresponds essentially to a conventional ACF bonding process.

[0412] As in Fig.21a and Figure 21b , the membrane 1 has no tail region which can be easily lifted, for example, formed by a protruding carrier matrix. Fig.21a and Figure 21bThe film 1 shown in FIG. 1 also does not require such a tail region, since it is applied directly to the target substrate 10, which already has mating contacts due to the contact layer 15, by means of which an electrical connection can be established between the conductive layer 3 of the film 1 and the conductive layer 3 c of the target substrate 10. Therefore, no tail region is required in this embodiment.

[0413] about Fig.21a and 21b The design of the layers in here refers to the above-mentioned implementation method.

[0414] Fig.22a and Figure 22b The method steps for producing an electrical functional element are shown. Fig.22a and Figure 22b Corresponds to Fig.21a and Figure 21b , the difference is that the membrane 1 additionally has a separation layer 13 and a protective lacquer layer 6. Regarding the design of the layers, reference is made to the above-mentioned embodiments. Fig.22a As shown in FIG, the carrier substrate 2 is designed to protrude so that Figure 22b As shown in FIG. 1 , the carrier substrate 2 can be easily removed after the film 1 has been applied to the target substrate 10. Fig.22a The membrane 1 shown in FIG. Fig.21a The film 1 shown in FIG. 1 is likewise applied to a target substrate 10 provided with a contact layer 15 , whereby an electrical connection is produced between the electrically conductive layer 3 of the film 1 and the electrically conductive layer 3 c of the target substrate 10 .

[0415] Figures 23a to 23d A top view of the target substrate 10 , the membrane 1 and the electrical functional element is shown.

[0416] so Fig.23a Target substrate 10 is shown, to which a contact layer is applied. The contact layer here has a connecting element 50. Preferably, the connecting element 50 is an integrated ZIF contact, which, as in Fig.23a As shown in FIG. 1 , the target substrate 10 is connected to the ACF contact area by means of a conductor line. In addition, it is possible that the target substrate 10 is transparent. The contact layer with the connecting element 50 is Fig.23a The contact layer of the target substrate 10 is designed here so that the two films can be applied to the target substrate 10. The target substrate 10 to which the two films are to be applied is Fig.23a A contact layer is already present in the sensor, which is designed in such a way that a two-layer sensor can be applied, comprising a film for the x layer and a film for the y layer.

[0417] Figure 23b The membranes 1 are shown, which together form a double-layer sensor. Figure 23bIn one embodiment, the x layer is formed in the film 1 and the y layer is formed in the film 1. It is possible, for example, that the x layer has an x ​​sensor of a touch sensor, which detects the x coordinate of a touch, and the y layer has a y sensor of a touch sensor, which detects the y coordinate of a touch. With regard to the design of the film 1, reference is made to the above-described embodiments.

[0418] As in Fig.23c As shown in , firstly, a first film 1, preferably with a first sensor layer, for example an x-layer, is applied to a target substrate 10 and electrical contact is established, in particular by means of an ACF bond. Advantageously, the first film 1, in particular the contact-making region of the first film, is applied with precise fit to a contact layer of the target substrate 10, in particular the connecting element 50 of the contact layer, in particular for electrically contacting the contact-making region of the first film, which contact layer is applied to the target substrate.

[0419] As in Fig.23d As shown in , preferably in a separate step, a second film 1 with a second sensor layer, for example a y-layer, is then applied with a connection element 50 that is precisely matched to the first film 1 or to a contact layer, especially a contact layer, of a target substrate 10, which is applied to the target substrate 10 for the purpose of, in particular, electrically contacting the contact contact area of ​​the second film 1. It is possible here that the adhesion between the sensor layers, for example, by means of OCA, can be omitted. The matching accuracy, that is to say the position accuracy of the second film relative to the first film in the x and y directions, is preferably ±350 μm, more preferably ±150 μm, in order to achieve the desired functionality of the electrical functional element, for example a touch sensor.

[0420] Figures 24a to 24e The method steps for producing the membrane 1 are shown. For this purpose, as in Fig.24a As shown in , a carrier matrix 2 is provided.

[0421] Then as Figure 24b As shown in , a conductive layer 3 is applied to a carrier substrate 2 at least partially. The conductive layer 3 is, for example, a metal layer of copper. The metal layer 3 is applied here at least in the following areas, which later constitute the functional area 21 and the contact connection area 20. The metal layer 3 is preferably applied by means of a vacuum metallization method, that is, the metal layer 3 is evaporated onto a possibly pretreated carrier substrate 2. The pretreatment of the carrier substrate 2 can be, for example, a corona or plasma treatment or the application of one or more layers of an adhesion promoter layer. In this way, for example, copper is heated to a temperature near the boiling point as a raw material. The individual atoms, atomic clusters or molecules of copper that escape here swim through the vacuum chamber and are deposited on the opposite, cooler carrier substrate 2. Thus, a thin layer of evaporated metal is formed on the carrier substrate 2. By using a mask, it is possible to evaporate the metal layer 3 locally. In addition, it is possible to increase the layer thickness of the thin copper layer formed by vacuum metallization by reinforcing the current.

[0422] As in Fig.24c As shown in, the metal layer 3 applied on the whole surface is then structured. For this reason, the technology of photolithography is preferably used, that is to say that the metal layer 3 is locally removed again by positive or negative exposure and corrosion or by a washing method corresponding to the formation of the electrical functional structure in the functional area 21 and the contact structure in the contact area 20. In this way, for example, a photoresist layer is first applied to the metal layer 3 for structuring the metal layer 3. The photoresist layer is then exposed by means of a mask and a lamp, such as a mercury vapor lamp or a laser, such as an excimer laser, wherein the exposed area corresponds to the area where the metal layer 3 should be removed. The exposed area of ​​the photoresist layer is then removed and an etching step is then implemented, which removes the metal layer 3 in the following area, in which the photoresist layer is removed. The remaining photoresist layer is then removed.

[0423] In the next optional step, as in Fig.24d , a protective lacquer layer 6 and a contact strengthening layer 7 are applied. The protective lacquer layer 6 and the contact strengthening layer 7 are poured in locally, for example by means of a slot casting machine (=nozzle). Fig.24d The contact strengthening layer 7 shown in FIG. 1 is a layer of carbon conductive paint. Fig.24d The protective lacquer layer 6 shown in is a layer of PAC. However, it is also possible to apply the protective lacquer layer 6 and the contact reinforcing layer 7 by means of gravure printing, for example reverse engraving or reverse coating, screen printing or relief printing, for example pad printing or flexographic printing.

[0424] The layers 4 , 5 , 6 and 7 are preferably dried physically, so that it is advantageous to dry them first, in particular before applying a further layer.

[0425] As in Fig.24e As shown in , the adhesion promoter layer 4 is then applied in the region 22. In contrast, no adhesion promoter layer 4 is applied in the region 23. The adhesion promoter layer 4 can be printed. Suitable printing methods are gravure printing, screen printing or relief printing methods. However, it is also possible to cast the adhesion promoter layer 4 in the region 22, for example by means of a slot casting machine. Alternatively, as in Fig.24e As shown in , the release layer 5 can be printed, for example, by screen printing. The release layer 5 can also be applied by another printing method, such as gravure or relief printing. The release layer 5 can also be applied by a slot casting machine. Fig.24eThe film 1 shown in FIG. 1 adheres to the target substrate in the region 22 with the adhesion promoter layer 4 after the film 1 is applied to the target substrate. In the region 23 with the contact area 20, on the other hand, the film 1 does not adhere to the target substrate. The above-described coating method can, as already explained, lead to surface roughness of the adhesion promoter layer 4, so that the adhesion promoter layer 4 has, for example, light-scattering properties in the state not yet applied to the target substrate. In particular, after the film 1 is applied, the adhesion promoter layer 4 is highly transparent, because the adhesion promoter layer 4 is melted, for example, by means of hot lamination and / or is flattened by means of pressure, so that the surface roughness of the adhesion promoter layer 4 no longer appears in a disturbing way in the visual appearance.

[0426] Fig.25a and Fig.25b The method steps for producing the membrane 1 are shown. For this purpose, as in Fig.25a , decorative layers 12c and 12d are provided. As already explained, the decorative layer 12c can be, for example, a transparent colored lacquer layer, which is arranged on the decorative layer 12d, which can be formed as a transparent carrier layer. The decorative layers 12c and 12d are applied to the intermediate adhesive layer 11 by means of hot embossing. However, it is also possible that the decorative layers 12c and 12d are applied to the intermediate adhesive layer 11, for example by means of cold embossing and / or by means of a heat transfer method and / or by means of a different lamination method. As shown in Fig.25b As shown in FIG. , the carrier layer 12 d remains on the membrane 1 here.

[0427] Furthermore, it is also possible to remove the carrier layer 12d so that Fig.25b Only the decorative layer 12 c remains on the film 1 .

[0428] Figures 26a to 26c The method steps for forming a film and / or an electrical functional element are schematically shown.

[0429] Fig.26a A film 1 is shown, which is implemented in multiple layers as stated above. With regard to the design of the layers, reference is made here to the above-mentioned embodiments. It is also possible that the film 1 has already been applied to a target substrate and / or an intermediate substrate, so that an electrical functional element is formed from the film 1 and the target substrate and / or the intermediate substrate. The film 1 and / or the electrical functional element can be shaped, in particular, by means of the shaping process described below. Preferably, the target substrate and / or the intermediate substrate has a layer thickness of a maximum of 1 mm, preferably 500 μm, so that the electrical functional element can be shaped.

[0430] Advantageously, the shaping takes place by means of a shaping process, preferably by means of deep drawing, hot forming, high pressure forming or by means of an injection molding process.

[0431] Preferably, the film 1 and / or the electrical functional element are formed by deep drawing. Figure 26bHere, for example, the film 1 is shown after forming by deep drawing. Advantageously, the film 1 and / or the electrical functional element is formed here by means of a vacuum, in particular at a negative pressure of up to 1 bar, and / or with the aid of an overpressure, in particular at an overpressure between 1 bar and 3 bar, in a forming mold corresponding to the desired forming geometry.

[0432] Furthermore, it is possible to shape the film 1 and / or the electrical functional element by means of thermoforming. Advantageously, the shaping process or the process parameters of the shaping process of the film 1 and / or the electrical functional element correspond to the shaping process / process parameters of deep drawing, wherein, for example, when using ABS material, the shaping is carried out with additional temperature assistance, in particular at a temperature between 120° C. and 300° C., preferably between 190° C. and 250° C. It is possible here that the carrier matrix and / or the target matrix comprises ABS material.

[0433] It is also possible to shape the membrane 1 and / or the electrical functional element by means of high pressure forming.

[0434] Advantageously, the shaping of the membrane 1 and / or the electrical functional element is carried out here with the aid of overpressure, in particular at an overpressure between 1 bar and 300 bar, preferably between 10 bar and 150 bar, in a shaping mold corresponding to the desired shaping geometry. It is expedient here that the shaping is carried out with additional temperature assistance, preferably at a temperature in the range of the glass transition temperature of the membrane 1 used.

[0435] Advantageously, the temperature is here between 120° C. and 300° C., preferably between 190° C. and 250° C., for example when using ABS material.

[0436] By means of the above-described forming process, a three-dimensional stretching of the film 1 and / or the electrical functional element of up to 200% is preferably achieved. It is also possible, especially when the parameters are optimized for the corresponding system, to achieve a stretching of up to 300%, wherein a stretching between 20% and 50% is sufficient in many cases of use.

[0437] As in Fig.26c As shown in FIG. 1 , a film 1 previously formed or preformed, for example by deep drawing, is back-injected with injection molding material 60 in a subsequent injection molding process.

[0438] It is also possible that the film 1 and / or the electrical functional element are formed and / or deformed by means of an injection molding process. Advantageously, the film 1 and / or the electrical functional element are introduced into the injection molding tool in a flat state by a roll or from a printed sheet or sheet or by a single sheet and deformed by means of an injection molding method, wherein in particular the molding is carried out by closing the mold and also by spraying in the molding material. In particular, the injection pressure is related to the component geometry and / or the component size here. For example, it is possible that the injection pressure is 500 bar and the injection molding temperature is between 180°C and 380°C, wherein the injection pressure and the injection molding temperature are related to the injection molding material. It is also suitable that the film 1 and / or the electrical functional element introduced into the injection mold are heated by means of heating the film 1 and / or the electrical functional element, for example, at a temperature between 30°C and 300°C, preferably between 80°C and 150°C, before the closing process of the injection mold. It is also possible that the film 1 and / or the electrical functional element are installed in the cavity by means of a clamping frame and / or a vacuum and / or an overpressure fit.

[0439] It is also advantageous that the film 1 and / or the electrical functional element is formed by "slipping" the film 1 and / or the electrical functional element onto the already three-dimensionally preformed component. Advantageously, the "slipping" of the film 1 and / or the electrical functional element is carried out during the process by controlling the vacuum suction of the film 1 and / or the electrical functional element onto the already three-dimensionally preformed component and simultaneously using an overpressure. Preferably, the already three-dimensionally preformed component to be slipped on is previously subjected to temperature. It is suitable here that the overpressure is between 1 bar and 50 bar, preferably between 3 bar and 15 bar, and / or the temperature is between 30°C and 300°C, preferably between 100°C and 180°C.

[0440] Preferably, the film 1 and / or the electrical functional element has a stretchability of more than 20%. Such a high stretchability cannot be achieved with conventional functional films, for example, by means of the above-mentioned forming and / or deformation processes, especially because carrier films such as PET are not sufficiently deformable and / or the conductive structure breaks after a small deformation, especially when stretched by more than 20%. It is shown here that the stretching is improved by the film 1 according to the invention. Thus, by the multi-layer structure of the film 1 according to the invention, especially by the at least one conductive layer embedded between multiple paint layers according to the sandwich system as described above, the mechanical stretching and / or deformation can be specifically influenced, in that, for example, by adapting the layer thickness or the paint formula, a certain area of ​​the film 1 can be designed to be more flexible or less flexible. Therefore, it is preferred to achieve the desired stretchability of more than 20% here.

[0441] It is also advantageous in the above-mentioned three-dimensional deformation that the electrically functional structure membrane 1 and / or the electrically functional element can be electrically contacted from the outside, in particular electrically, for which purpose the electrical contacts must be accessible for contacting. Alternatively, inductive and / or capacitive coupling, in particular coupling via antennas, can be achieved. As stated above, the membrane 1 according to the invention enables stable and reliable contacting of the electrically functional structure. Reference numerals list

[0442] 1 film

[0443] 2 Carrier Matrix

[0444] 3. 3a, 3b, 3c, 30 conductive layer

[0445] 4 Adhesion enhancer layer

[0446] 5 Peeling Layer

[0447] 6 Protective paint layer

[0448] 7Contact reinforcement layer

[0449] 8 Dielectric Layers

[0450] 9 Darkening Layer

[0451] 10 Target Matrix

[0452] 11Intermediate Adhesion Layer

[0453] 12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, 12i, 12j decorative layer

[0454] 13 Separation layer

[0455] 14 Primer Layer

[0456] 15 Contact layer

[0457] 20, 20a, 20b, 20c contact area

[0458] 21 Functional Areas

[0459] Areas 22, 23, 23a, 24, 25

[0460] 26 Guide track width

[0461] 27 Guide track distance

[0462] 30v local

[0463] 31, 32, 31a, 32a conductor lines

[0464] 33 face elements

[0465] 40 upper side

[0466] 41 lower side

[0467] 42, 43 interface

[0468] 50 connection elements

[0469] 51 adapter element

[0470] 52 contact elements

[0471] 60 Injection molding materials

[0472] 70 transfer layers

Claims

1. A film (1) comprising a carrier substrate (2), an adhesion promoter layer (4) for applying the film (1) to a target substrate (10), and at least one electrically conductive layer (3), wherein the at least one electrically conductive layer (3) forms an electrically functional structure in a functional region (21), wherein the at least one electrically conductive layer (3) forms at least one contact structure in at least one contact region (20) for contacting the electrically functional structure, and the adhesion promoter layer (4) is applied over the entire surface when viewed perpendicularly to a plane defined by the carrier substrate (2), wherein: The adhesion promoter layer (4) is arranged on the side of the carrier substrate (2) facing away from the at least one electrically conductive layer (3), and The adhesion promoter layer is arranged on the surface of the film. The adhesion promoter layer (4) is formed by a cold adhesive or a radiation-curable adhesive applied by gravure, screen printing, relief printing or casting technology, The adhesion promoter layer (4) is made of a material that is highly transparent after being applied to the target substrate (10), and The adhesion promoter layer (4) comprises two layers, namely a first adhesion promoter layer and a second adhesion promoter layer, wherein the second adhesion promoter layer is arranged between the first adhesion promoter layer and the target substrate (10).

2. The membrane (1) according to claim 1, characterized in that The film (1) comprises a release layer (5), wherein the release layer (5) at least partially covers the at least one contact-making region (20) when viewed perpendicularly to a plane defined by the carrier substrate (2).

3. The membrane (1) according to claim 2, characterized in that The release layer (5) covers a region (24) adjacent to the at least one contact-making region (20).

4. The membrane (1) according to claim 2 or 3, characterized in that The release layer ( 5 ) has a layer thickness between 0.1 μm and 10 μm.

5. The membrane (1) according to any one of claims 1 to 3, characterized in that The adhesion promoter layer ( 4 ) is a layer of a polymer and / or a copolymer.

6. The membrane (1) according to any one of claims 1 to 3, characterized in that The adhesion promoter layer ( 4 ) has a layer thickness between 0.1 μm and 50 μm.

7. The membrane (1) according to any one of claims 1 to 3, characterized in that The adhesion promoter layer (4) is made of a material which, after being applied to the target substrate (10), has a transmittance of more than 85% for light in the wavelength range between 380 nm and 780 nm.

8. The membrane (1) according to any one of claims 1 to 3, characterized in that The adhesion promoter layer (4) is made of a material which, after being applied to the target substrate (10), deflects less than 8% of light in the wavelength range between 380 nm and 780 nm by scattering.

9. The membrane (1) according to any one of claims 1 to 3, characterized in that The adhesion promoter layer (4) is formed from an adhesive that can be cured by electromagnetic radiation and / or electron radiation.

10. The membrane (1) according to any one of claims 1 to 3, characterized in that The membrane (1) has a protective lacquer layer (6).

11. The membrane (1) according to claim 10, characterized in that When viewed perpendicularly to a plane defined by the carrier substrate (2), the protective lacquer layer (6) at least partially covers the at least one electrically conductive layer (3).

12. The membrane (1) according to claim 11, characterized in that The protective lacquer layer ( 6 ) has a layer thickness of between 0.1 μm and 50 μm.

13. The membrane (1) according to claim 10, characterized in that The protective lacquer layer (6) is a transparent protective lacquer layer.

14. The membrane (1) according to claim 10, characterized in that The protective lacquer layer (6) is arranged between the at least one electrically conductive layer (3) and the adhesion promoter layer (4).

15. The membrane (1) according to any one of claims 1 to 3, characterized in that The at least one contacting structure for contacting an electrical functional structure is an electrical terminal.

16. The membrane (1) according to any one of claims 1 to 3, characterized in that The at least one conductive layer (3) has a contact strengthening layer (7).

17. The membrane (1) according to claim 16, characterized in that The at least one electrically conductive layer (3) comprises the contact reinforcement layer (7) at least in places in the at least one contact-making region (20), wherein the contact reinforcement layer protects the at least one contact-making region (20) against mechanical, physical and / or chemical environmental influences.

18. The membrane (1) according to claim 16, characterized in that The contact strengthening layer (7) has a layer thickness between 0.1 μm and 100 μm.

19. The membrane (1) according to claim 16, characterized in that The contact strengthening layer (7) is formed by a conductive paste containing silver, gold, aluminum, copper, chromium and / or other conductive metals.

20. The membrane (1) according to any one of claims 1 to 3, characterized in that After being applied to a target substrate (10), the film (1) has a transmittance of more than 75% for light in the wavelength range between 380 nm and 780 nm at least in the functional region (21) of the at least one electrically conductive layer (3).

21. The membrane (1) according to any one of claims 1 to 3, characterized in that The electrically functional structure constitutes a touch sensor area, and the touch sensor area provides a touch area function.

22. The membrane (1) according to any one of claims 1 to 3, characterized in that The film (1) has at least two conductive layers, namely at least a first conductive layer (3a) and a second conductive layer (3b).

23. The membrane (1) according to claim 22, characterized in that When viewed perpendicularly to a plane defined by the carrier substrate (2), the at least two electrically conductive layers are arranged at least partially overlapping.

24. The membrane (1) according to claim 22, characterized in that The at least two conductive layers are arranged to precisely match each other.

25. The membrane (1) according to any one of claims 1 to 3, characterized in that The at least one electrically conductive layer (3) has a plurality of conductor tracks (31, 32).

26. The membrane (1) according to claim 22, characterized in that The at least two electrically conductive layers have a plurality of conductor tracks (31, 32).

27. The membrane (1) according to claim 25, characterized in that The conductor paths (31, 32) are spaced apart from one another.

28. The membrane (1) according to claim 26, characterized in that The conductor lines (31, 32) of the first conductive layer (3a) and the second conductive layer (3b) are respectively arranged according to a wire grid.

29. The membrane (1) according to claim 26, characterized in that The conductor tracks (31, 32) of the first conductive layer (3a) and the second conductive layer (3b) are structured.

30. The membrane (1) according to claim 26, characterized in that The contact-making regions (20a, 20b) of the at least two electrically conductive layers merge into a common contact-making region (20c).

31. The membrane (1) according to claim 30, characterized in that The common contact region (20c) is electrically contacted via an adapter element (51).

32. The membrane (1) according to claim 25, characterized in that The conductor tracks (31, 32) are formed from metal with a layer thickness of between 1 nm and 100 nm.

33. The membrane (1) according to claim 25, characterized in that The conductor tracks (31, 32) are formed from a conductive paste containing silver, gold, copper and / or carbon.

34. The membrane (1) according to any one of claims 1 to 3, characterized in that The film (1) has at least one intermediate adhesive layer (11).

35. The membrane (1) according to claim 34, characterized in that The at least one electrically conductive layer (3) is arranged between the carrier substrate (2) and the at least one intermediate adhesive layer (11).

36. The membrane (1) according to claim 34, characterized in that The at least one intermediate adhesive layer (11) is arranged on a side of the carrier substrate (2) facing away from the at least one electrically conductive layer (3).

37. The membrane (1) according to claim 34, characterized in that When viewed perpendicularly to a plane defined by the carrier substrate (2), the at least one intermediate adhesive layer (11) at least partially does not cover the at least one contact-making region (20).

38. The membrane (1) according to claim 34, characterized in that The intermediate adhesive layer (11) at least partially covers the functional area (21).

39. The membrane (1) according to claim 37, characterized in that The intermediate adhesive layer (11) does not cover the at least one contact-making region (20) over the entire surface.

40. The membrane (1) according to claim 34, characterized in that When viewed perpendicularly to a plane defined by the carrier substrate (2), the at least one intermediate adhesion layer (11) is arranged substantially in the same region (22) as the adhesion promoter layer (4).

41. The membrane (1) according to any one of claims 1 to 3, characterized in that The film has one or more decorative layers (12a-j).

42. The membrane (1) according to claim 41, characterized in that The one or more decorative layers (12a-j) are arranged on a side of the carrier substrate (2) facing away from the at least one electrically conductive layer (3) and / or the one or more decorative layers (12a-j) are arranged on a side of the at least one electrically conductive layer (3) facing away from the carrier substrate (2).

43. The membrane (1) according to claim 34, characterized in that The film has one or more decorative layers (12a-j), and the at least one intermediate adhesive layer (11) is arranged between the carrier substrate (2) and the one or more decorative layers (12a-j).

44. The membrane (1) according to claim 41, characterized in that The one or more decorative layers (12a-j) comprise at least one layer selected from the group consisting of a protective layer, a colored lacquer layer, a metal layer, a reflective layer, a replication lacquer layer, a transparent layer, a carrier layer and / or a layer producing a variable visual effect.

45. The membrane (1) according to claim 41, characterized in that At least one of the one or more decorative layers (12a-j) has a surface relief structure at least partially.

46. ​​The membrane (1) according to claim 41, characterized in that The film (1) has at least one intermediate adhesive layer (11), and the one or more decorative layers (12a-j) are arranged in substantially the same region (22) as the adhesion promoter layer (4) and / or the intermediate adhesive layer (11).

47. The membrane (1) according to any one of claims 1 to 3, characterized in that The film (1) comprises a primer layer (14).

48. The membrane (1) according to claim 47, characterized in that The primer layer ( 14 ) has a layer thickness of between 0.1 μm and 5 μm.

49. The membrane (1) according to any one of claims 1 to 3, characterized in that The membrane (1) comprises a separation layer (13).

50. The membrane (1) according to claim 49, characterized in that The separation layer (13) is arranged between the carrier matrix (2) and the at least one electrically conductive layer (3).

51. The membrane (1) according to claim 49, characterized in that The membrane (1) comprises a protective lacquer layer (6), the separating layer (13) being arranged between the carrier substrate (2) and the protective lacquer layer (6).

52. The membrane (1) according to claim 51, characterized in that The adhesion between the carrier substrate (2) and the protective lacquer layer (6) is 20% to 80% lower than the adhesion between the protective lacquer layer (6) and / or the at least one electrically conductive layer (3) and / or the adhesion promoter layer (4) due to the separating layer (13) arranged between the carrier substrate (2) and the protective lacquer layer.

53. The membrane (1) according to any one of claims 1 to 3, characterized in that The carrier matrix ( 2 ) has a layer thickness of between 2 μm and 250 μm.

54. The membrane (1) according to any one of claims 1 to 3, characterized in that The carrier substrate (2) is a transparent carrier substrate.

55. The membrane (1) according to any one of claims 1 to 3, characterized in that The carrier matrix (2) is formed from a hybrid material comprising a plastic layer and a layer made of a fiber material.

56. The membrane (1) according to any one of claims 1 to 3, characterized in that The film (1) can be formed using a forming process.

57. The membrane (1) according to claim 56, characterized in that The film (1) can be formed by deep drawing, thermoforming, high pressure forming or by injection molding.

58. A method for producing a membrane (1), said membrane being a membrane according to any one of claims 1 to 57, wherein said method comprises the following steps: a) providing a carrier matrix (2); b) applying at least one electrically conductive layer (3) to the carrier substrate (2), wherein the at least one electrically conductive layer (3) forms an electrically functional structure in the functional region (21), wherein the at least one electrically conductive layer (3) forms at least one contact structure for contacting the electrically functional structure in at least one contact region (20); c) applying an adhesion promoter layer (4) for applying the film (1) to a target substrate (10) in such a way that the adhesion promoter layer (4) is applied over the entire surface when viewed perpendicularly to a plane defined by the carrier substrate (2), wherein the adhesion promoter layer (4) is arranged on the side of the carrier substrate (2) facing away from the at least one electrically conductive layer (3), and The adhesion promoter layer is arranged on the surface of the film. The adhesion promoter layer (4) is formed by a cold adhesive or a radiation-curable adhesive applied by gravure, screen printing, relief printing or casting technology, The adhesion promoter layer (4) is made of a material that is highly transparent after being applied to the target substrate (10), and The adhesion promoter layer (4) comprises two layers, namely a first adhesion promoter layer and a second adhesion promoter layer, wherein the second adhesion promoter layer is arranged between the first adhesion promoter layer and the target substrate (10).

59. The method according to claim 58, characterized in that In step b), the at least one conductive layer (3) is a metal layer, and step b) further comprises the following steps: Evaporation of metal layer; The metal layer is structured by removing the metal layer locally.

60. The method according to claim 58, characterized in that The following steps are carried out between step b) and step c): The contact strengthening layer (7) is applied in such a way that the at least one electrically conductive layer (3) comprises the contact strengthening layer (7).

61. The method according to any one of claims 58 to 60, characterized in that The following steps are further performed between step b) and step c): A protective lacquer layer (6) is applied.

62. The method according to any one of claims 58 to 60, characterized in that The method further comprises the following steps: e) applying the release layer (5) in such a way that, when viewed perpendicularly to a plane defined by the carrier substrate (2), the release layer (5) at least partially covers the at least one contact-making region (20).

63. The method according to any one of claims 58 to 60, characterized in that The method further comprises the following steps: f) Applying an intermediate adhesive layer (11).

64. The method according to any one of claims 58 to 60, characterized in that The film (1) has a protective lacquer layer (6), and / or the film (1) includes a release layer (5), wherein the release layer (5) at least partially covers the at least one contact-making area (20) when viewed perpendicularly to a plane defined by a carrier substrate (2), and / or the film (1) has at least one intermediate adhesion layer (11), and / or the at least one conductive layer (3) has a contact reinforcement layer (7), and the protective lacquer layer (6), the release layer (5), the intermediate adhesion layer (11) and / or the contact reinforcement layer (7) are applied by gravure printing, screen printing, relief printing or casting technology.

65. The method according to any one of claims 58 to 60, characterized in that The method further comprises the following steps: g) Applying one or more decorative layers (12a-j).

66. The method according to claim 65, characterized in that In step g), the one or more decorative layers (12a-j) are applied in such a way that the one or more decorative layers (12a-j) are arranged in essentially the same region (22) as the adhesion promoter layer (4) and / or the intermediate adhesive layer (11).

67. The method according to claim 65, characterized in that The one or more decorative layers (12a-j) are applied using hot embossing, cold embossing, thermal transfer and / or lamination.

68. Use of the film (1) according to any one of claims 1 to 57 for application to a target substrate (10).

69. A method for producing an electrical functional element, wherein the method comprises the following steps: a) providing a film (1) according to any one of claims 1 to 57; b) Applying the film (1) to the target substrate (10).

70. The method according to claim 69, characterized in that In step b), the film (1) is applied from a roll to a target substrate (10) by means of hot lamination.

71. The method according to claim 70, characterized in that In step b), the film (1) from the sheet is applied to the target substrate (10) by means of hot lamination.

72. The method according to claim 70 or 71, characterized in that The hot lamination is carried out at a temperature in the range between 80° C. and 300° C. and / or at an embossing pressure in the range between 200 and 2000 bar.

73. The method according to claim 69, characterized in that In step b), the film ( 1 ) is applied to the target substrate by injection molding material.

74. The method according to any one of claims 69 to 71, characterized in that The adhesion promoter layer ( 4 ) is made of a material whose visual appearance changes from cloudy to highly transparent and / or clear during and / or after step b).

75. The method according to claim 69, characterized in that In step b), the film is applied to the target substrate using hot embossing.

76. The method according to claim 75, characterized in that The embossing temperature is in the range of 80°C to 250°C and / or the embossing pressure is 0.5 kN / cm 2 Up to 10kN / cm 2 and / or the printing time is in the range of 1 ms to 2000 ms.

77. Electrical functional element comprising a membrane (1) according to any one of claims 1 to 57.

78. The electrical functional element according to claim 77, characterized in that The adhesion promoter layer (4) of the film (1) has a transmittance of more than 85% for light in the wavelength range between 380 nm and 780 nm, and / or the adhesion promoter layer (4) of the film (1) deflects less than 8% of the light in the wavelength range between 380 nm and 780 nm by scattering.

Images