Method for applying a protective layer, protective layer itself and semi-finished product with a protective layer

Abstract

A method for applying a winding protection layer (4) for the production of a semi-finished product (1) of organic electronic components, comprising a layer stack (3) on a substrate film (2) optionally with a barrier function, wherein the winding protection layer (4) protects the layer stack (3) before and during the final production of the semi-finished product from environmental influences and damage caused by handling, characterized in that the method is a continuous roll-to-roll process in a vacuum, which comprises the following steps: - application of a water- and solvent-free protective layer material (5), which is at least temporarily fluid during the application phase, crosslinkable or curable, compatible with the layer stack (3) in the fluid and solid phases as well as with the conditions during the roll-to-roll process, and which has a viscosity of at least 10 mPa·s and at most 5·105 mPa·s during the application phase, by means of a printing process,which includes at least one of the processes screen printing, flexographic printing, plotting, inkjet printing, slot nozzle printing or a process suitable for 3D printing, - area-wide or selective local crosslinking or curing of the protective layer material (5) by at least one of the processes UV crosslinking, thermal crosslinking, cooling or drying.

Description

Field of invention

[0001] The invention relates to a protective layer, also referred to as a winding protective layer, and a method for applying a protective layer in a continuous roll-to-roll process for the production of a damage-free handleable semi-finished product of organic electronic components, in particular optoelectronic components, such as solar cells or LEDs, TFTs, etc. State of the art

[0002] Organic electronics is a subfield of electronics that uses electronic circuits made from electrically conductive polymers or smaller organic compounds.

[0003] A key characteristic of organic electronics is the use of microelectronic components on substrates made of organic films, as well as conductive traces and components fabricated from conductive organic molecules (organic semiconductors). The organic materials are applied to the films in the form of thin films or small volumes, either printed, bonded, coated, vapor-deposited, or otherwise. All methods used for electronics on ceramic or semiconducting substrates are also suitable for manufacturing these thin layers.

[0004] Optoelectronic components are widely used today in everyday and industrial environments. Components with organic layers are of particular interest, as their flexible structure allows them to be arranged on curved or domed surfaces.

[0005] Organic electronics is redundant to silicon technology in many application areas, but offers advantages such as low cost, making it suitable for disposable electronics, and low overall component thickness, which facilitates integration. The fabrication of these thin films is possible under much milder conditions, allowing the use of flexible plastic films as substrates and thus enabling the creation of inherently flexible and, in some cases, stretchable components.

[0006] Organic light-emitting diodes (OLEDs) are also known; because they do not require backlighting, they can be made very thin and therefore flexible. Solar cells with organic active layers, which are also flexible, are another well-known technology. These organic active layers can be composed of polymers, as described, for example, in US patent 7,825,326 B2, or small molecules, as described in EP patent 2,385,556 A1. Further applications include light sensors and field-effect transistors.

[0007] The electronic components comprise at least two electrodes, one of which is applied to the substrate and the other, serving as a counter electrode, is applied to the side facing away from the substrate. At least one photoactive layer, preferably an organic photoactive layer, is located between the electrodes. Further layers, such as transport layers, may be arranged between the electrodes.

[0008] While polymers are characterized by the fact that they are not vaporizable and can therefore only be applied from solutions, small molecules are usually vaporizable and can be processed solvent-free by evaporation or sublimation with or without carrier gas.

[0009] The advantage of such organic-based components over conventional inorganic-based components, especially semiconductors like silicon or gallium arsenide, lies in the sometimes extremely high optical absorption coefficients of organic materials, up to 2 × 10⁻⁶. 5 cm –1 This opens up the possibility of producing very thin components with minimal material and energy expenditure. Further technological aspects include low costs, the ability to manufacture flexible, large-area components on plastic films, and the virtually unlimited design possibilities and the unlimited availability of organic chemistry.

[0010] A solar cell converts light energy into electrical energy, while an OLED converts electrical energy into light. The term "photoactive" also refers to the conversion of light energy into electrical energy and vice versa. Unlike inorganic solar cells, organic solar cells do not directly generate free charge carriers from light. Instead, excitons, i.e., electrically neutral excited states (bound electron-hole pairs), are formed first. Only in a second step are these excitons separated into free charge carriers, which then contribute to the electric current flow. Known designs of organic solar cells are disclosed, for example, in WO 2004 083 958 A2, WO 2006 092 135 A1, WO 2006 092 134 A1, EP 107 25 079 A1, WO 2010 139 804 A1, and WO 2011 064 330 A1.

[0011] The production of optoelectronic components is carried out depending on the organic materials used in the active organic layer by sputtering, spin coating or printing, as well as by vapor deposition (CVD, OVPD) and by structuring measures such as laser structuring or wet lithographic structuring.

[0012] A roll-to-roll process is understood to be a continuous process, in contrast to a batch process in which individual components are processed sequentially. Generally, a continuous process means that a technical manufacturing process is carried out without interruptions. Preferably, the substrate or component being manufactured is continuously fed into the process. Specifically, this means that at least semi-finished parts, components, or parts are produced in more than one process step using a continuous process, for example, a substrate film made from a carrier film with a conductive layer stack. The roll-to-roll process is characterized, for example, by a continuous belt of plastic film, such as PET or PEN.Materials are applied to this tape to form electronic components, in particular by vapor deposition, printing, coating, sputtering or plasma deposition, and structured by, for example, laser cutting, etching, scratching or cutting.

[0013] One problem with the roll-to-roll manufacturing of optoelectronic components with organic layers is that the substrates are separated only by electrical insulation, typically introduced through laser, lithographic-chemical, or mechanical processes. The substrates are on the roll and, once they leave the continuous roll-to-roll process, must be both separated from each other and adequately sealed against external environmental influences for completion.

[0014] While it is advantageous for complete production to use several consecutive roll-to-roll systems, which can be operated under atmospheric, inert, or low-pressure conditions as required, in order to reduce the complexity of the individual systems, it is also practical to use one roll-to-roll system for the production of the organic components and another system for their subsequent encapsulation, since the process environments of these two production steps can differ significantly. The process separation occurs, for example, after the complete deposition and structuring of the functional organic components (see German patent application DE 10 2012 106 607 A1).

[0015] However, a problem arises because the already completed layers must always be protected from moisture, solvents, and / or mechanical stress between processing steps. Furthermore, the adhesion between the organic layer stack and the counter electrode is usually weak, which means that winding and unwinding the continuous substrate along with the complete layer stack is highly likely to damage the organic components located on the continuous substrate.

[0016] To protect the semi-finished product, a protective layer is therefore required (see, for example, the publications DE 10 2004 024 461 A1, DE 10 2011 075 081 A1 and DE 10 2010 014 299 A1). This ensures damage-free transfer to a subsequent machine and more robust further processing of the semi-finished product, even when contact on both sides of the film is possible.

[0017] In current technology, a polymer film is applied as a protective layer. However, without special measures, such as elaborate drying, a prefabricated film exhibits high moisture content. This leads to damage to the moisture-sensitive component being covered.

[0018] Other methods for forming a top layer are known, but cannot be used for producing a protective layer according to the preamble of the invention. For example, the method described in German patent DE 10 2008 026 216 B4 involves applying a lacquer, but its solvent content, which damages the layer stack, makes the method unsuitable for the present purpose. Furthermore, it is known from German patent DE 10 2009 025 123 A1 to apply layers by extruding a polymer from a slot die. The relatively high temperatures required to melt the polymer and the mechanical stress resulting from the extrusion process mean that this method is also unsuitable for applying a protective layer intended to directly cover the organic layer stack. Summary of the invention; Technical task

[0019] There is therefore a particular need to develop methods for applying a permanent protective layer to the counter electrode of a layer stack of an electronic component, characterized by the absence of any negative interactions with the layer stack of the electronic component being protected. Furthermore, the method should be integrable into the roll-to-roll processes used to manufacture the organic semi-finished product.

[0020] The object of the present invention is therefore to provide a semi-finished product with a protective layer, so that the layer stack of the electronic component is protected from environmental influences and damage during further processing during the final assembly phase. Neither the applied protective layer itself nor the method for producing or applying the protective layer may have adverse effects on the further processing of the semi-finished product or on the functional layers of the layer stack to be protected. Furthermore, it is required that the method for producing the protective layer be simple, flexible, and cost-effective, and that it can be integrated into the roll-to-roll process.

[0021] Another task is to specify the properties of the protective layer and the method for applying the protective layer. Technical solution: Method for applying a protective layer

[0022] The problem is solved by a method for applying a protective layer in a continuous roll-to-roll process for the production of a semi-finished product of organic electronic components, comprising a layer stack on a substrate film, wherein the protective layer protects the layer stack from environmental influences and damage caused by handling before and during final production, wherein a protective layer material that is at least temporarily fluid, crosslinkable or curable during the application phase and compatible with the layer stack in the fluid and solid phases as well as with the conditions during the roll-to-roll process is applied in such a way that a functional protective layer is formed.The material is compatible with the layer stack if it does not have any adverse effects on the layer stack; the material is compatible with the process if it neither causes disturbances in the process flow nor changes itself due to the conditions during the process flow in a way that would be detrimental to the material itself, the layer stack, or the process.

[0023] A preferred embodiment provides that the semi-finished product to be coated with the protective layer is an optoelectronic component. This includes emissive components such as OLEDs or energy converters such as photovoltaic modules and light sensors, but also field-effect transistors.

[0024] A particularly preferred embodiment comprises, as the layer stack to be protected, an optoelectronic device comprising at least two electrodes, wherein one electrode is applied to a substrate which optionally includes a barrier function against water vapor, oxygen, or water, and the other electrode is applied as a counter electrode on the side facing away from the substrate, further comprising at least one photoactive layer between the electrodes. Preferably, the layer stack to be protected is produced predominantly by evaporating or sublimating small molecules with or without a carrier gas onto a substrate. The layer stack to be protected may also include further functional layers, for example, transport or passivation layers.

[0025] It has proven beneficial to use protective layer materials that are water- and solvent-free in their liquid state. This prevents or reduces the release / dissolution of organic materials from the layer stack, for example through diffusion.

[0026] Furthermore, optimal adaptation to the conditions in the manufacturing process of the semi-finished product is provided, so that the application of the protective layer can take place under lower pressure, i.e. negative pressure.

[0027] Furthermore, it is planned that the manufacturing process for applying the protective layer will take place in a vacuum, preferably in a rough or fine vacuum.

[0028] Alternatively, the adaptation can also be achieved by pretreating the printing material, e.g. by outgassing dissolved gases before use in a vacuum.

[0029] An alternative embodiment of the inventive method provides that the protective material is applied with or without a carrier gas.

[0030] In a preferred embodiment, the functional protective layer is produced with a thickness of at least 50 nm and at most 200 µm, particularly preferably with a thickness of at least 5 µm and at most 100 µm.

[0031] However, applying the protective layer material using a printing process has proven particularly advantageous. A wide variety of materials are available for printing, allowing selection based on criteria that specifically consider compatibility with the layer stack and the intended process conditions. This avoids printing materials containing solvents or moisture incompatible with the organic layer stack, where evaporation is intended to cure the applied layer. Instead, other methods adapted to the requirements of the layer stack are used to crosslink (cure) the protective layer material after printing. Solvent-free inks are preferred.

[0032] The printing process must include at least one of the following methods: screen printing, flexographic printing, slot die printing, plotting, inkjet printing, or a method suitable for 3D printing. Screen printing is suitable for quickly coating large areas. It allows for level adjustment and the use of thick-film technology (several hundred nm). Inkjet printing, in turn, is easy to use. Plotting is particularly advantageous for polymer LEDs because it is easy to use, allows for coating large areas, and also enables level adjustment.

[0033] By using processes employed in 3D printing, it is particularly easy to give the resulting protective layer a desired topography. In 3D printing, the structure is built up using computer-controlled technology from one or more liquid or solid materials according to predefined dimensions and shapes (CAD). Physical or chemical hardening or melting processes take place during the build process. Typical materials for 3D printing include plastics, synthetic resins, ceramics, and metals – thus representing a very broad spectrum of usable materials. In particular, the inventive process comprises the following methods.

[0034] In one embodiment of the invention, the Fused Deposition Modeling (FDM) process has proven effective. This rapid prototyping manufacturing method involves building a workpiece layer by layer from a meltable plastic. This process is based on the liquefaction of a wire-like plastic or wax material by heating. Upon subsequent cooling, the material solidifies. Material is applied by extrusion using a heating nozzle that can move freely within the build plane. According to the prior art, layer thicknesses range from 0.025 to 1.25 mm. This allows the protective layer according to the invention to be easily textured. A particular advantage over other polymer extrusion methods is the small amount of material that exits the heating nozzle at any one time.This allows the heat input to the substrate, such as the layer stack, to be controlled even if the material temperature is potentially higher. In this way, the amount of hot protective coating material applied to a specific location within a given time can be precisely adjusted to ensure that the substrate temperature does not exceed a certain limit. Once the applied material has cooled sufficiently in a given area, more material can be applied to achieve the desired layer thickness or texture.

[0035] Another 3D printing method suitable for carrying out the present invention is Multi Jet Modeling. The term Multi Jet Modeling (MJM) (also Polyjet Modeling) refers to a rapid prototyping method in which a model is built up layer by layer by a print head with several linearly arranged nozzles, functioning similarly to the print head of an inkjet printer. Due to the small size of the droplets produced by these systems, even fine details and thin layers can be reproduced. A print resolution of 450 dpi and higher is technically possible. UV-sensitive photopolymers are suitable materials for a protective layer produced in this way. These printing materials, in the form of monomers, are polymerized immediately after printing using UV light, thereby changing from a liquid state to a solid state.By using a two-head system, different materials can also be combined, for example to combine different properties or to achieve an optical effect.

[0036] The crosslinking or curing of the protective layer material comprises at least one of the following processes: UV crosslinking, as previously described in relation to Multi Jet Modeling; thermal crosslinking, preferably through the local application of a heat source that does not damage the layer stack; and drying. Drying in this context does not refer to drying by the evaporation of water or solvents, as water or solvents in the protective layer material would damage the layer stack.

[0037] A protective layer material is used that is water- and solvent-free in its liquid state to prevent damage to the organic layer stack. Preferably, the protective layer material is electrically insulating, at least after crosslinking. Furthermore, it is advantageous if the protective layer material has a vapor pressure lower than the ambient pressure used in the manufacturing process. This prevents undesirable evaporation of the protective layer material under the potentially low pressure during roll-to-roll processing in the respective plant.

[0038] According to the invention, it is provided that at least one of the material groups thermoplastics, thermosets or elastomers is used as the protective layer material.

[0039] Furthermore, according to the invention, at least one of the material groups phenolic resins, amino resins, unsaturated polyester resins, vinyl ester resins, epoxy resins, silicone resins (e.g., silicon acrylate-based resins), epoxysiloxanes, dicyclopentadiene or diallyl phthalate resins is provided as a protective layer material.

[0040] Furthermore, according to the invention, aromatic, aliphatic, halogen-free or halogen-containing polyolefins, or aromatic, aliphatic, saturated or unsaturated polyesters, or polyamides, or polyurethanes, or phenol-formaldehyde resins or poly(organo)siloxanes are used as protective layer materials.

[0041] Investigations have shown that the protective coating material to be applied must have a certain minimum viscosity to prevent it from running off the layer stack during the manufacturing process if no special edge restraints are provided. It has proven particularly advantageous if the viscosity of the protective coating material during application is at least 10 mPa·s, preferably greater than 50 mPa·s, and most preferably greater than 10 2 mPa·s is located.

[0042] Furthermore, to ensure a fluid application of the protective layer material, it is essential to ensure that the protective layer material has a corresponding maximum viscosity during application so that the protective layer material can still be applied cleanly according to the invention, and that manufacturing-related irregularities, for example from laser processing, are completely embedded. If the viscosity of the protective layer material is too high, there is a risk that the cover contacts will be pressed into the underlying layers of the stack, leading to undesirable damage. It has proven particularly advantageous if the viscosity of the liquid protective layer material is at most 5 × 10⁻⁶. 5 mPa·s, particularly preferably at a maximum of 10 4 mPa·s is; most preferably a maximum of about 10 3 mPa·s is located.

[0043] Alternatively, the protective layer material used can be pre-polymerized to achieve a certain minimum viscosity.

[0044] It has proven particularly advantageous if the functional protective layer fulfills at least one of the additional functions of smoothing the layer stack, leveling the height with the layer stack, improving the adhesion of an encapsulation and keeping contact points clear, or if it contains added getters.

[0045] Height leveling can be used, for example, to obtain a semi-finished product with a uniform layer thickness. This is achieved by applying more protective coating material to areas that are lower due to the manufacturing process than to higher areas, such as the stack of layers. After the protective coating has been applied, the semi-finished product is planar.

[0046] This facilitates subsequent processing, such as embedding between rigid materials.

[0047] In contrast, according to the invention, smoothing the layer stack is understood to mean providing the semi-finished product with a protective layer so that small manufacturing-related "burrs" are smoothed out, but an approximately uniform thickness of the protective layer is applied, so that the protective layer covers the optoelectronic component and manufacturing-related discontinuities are concealed. This results in a semi-finished product with a protective layer that is not perfectly planar. Fig. Figure 13 shows the difference between leveling (a) and smoothing (b). The areas of the dashed circles in the smoothing section are intended to highlight the difference between the terms.

[0048] In both processes, smoothing the layer stack and leveling the height, it must be ensured that the optoelectronic component is covered at least to the extent that the unevenness caused by the manufacturing process, for example by the laser processing of the cover electrode, is covered.

[0049] The adhesion of the subsequent encapsulation to the protective layer can be improved by giving the protective layer a suitable structure, for example, a rough structure to improve adhesive adhesion. Furthermore, it would be possible to connect the encapsulation to the protective layer by means of a positive fit, preferably by incorporating complementary structures into the protective layer and the encapsulation.

[0050] Furthermore, according to the invention, an additional layer is applied to the protective layer. This layer is selected to prevent the electrode from detaching from the stack during unwinding, particularly during longer storage times until further processing.

[0051] The additional layer can be temporarily applied in the form of a film, so that it can be removed again during further processing when the semi-finished product is unrolled.

[0052] Alternatively, the additional layer can also be applied as a permanent layer, for example, to promote adhesion during subsequent encapsulation. The materials for the additional layer are selected from those of the protective layer. Alternatively, transparent inorganic materials can also be used.

[0053] According to the invention, an additional layer is applied to the layer stack of the optoelectronic component before the protective layer is applied, in order to incorporate attractive additional functions, such as light coupling.

[0054] Another advantage is the ease with which contact points can be kept clear. Without having to cover them beforehand or subsequently remove a protective layer, the surface can be coated during the printing process – particularly flexibly with all printhead-based printing methods – in such a way that the area of ​​the contacts and / or busbars is kept free of protective layer material from the outset and is not printed on.

[0055] In this context, it is also intended to ensure that the contacts remain unobstructed even if the chosen printing method does not initially allow for this. This is particularly relevant when applying the protective coating material using a wide-slot nozzle, which covers the entire surface across the nozzle width with the liquid protective coating material, without the possibility of excluding individual areas. If crosslinking is then carried out by a UV lamp or another suitable radiation source, this can be done selectively so that the intended contact areas remain uncrosslinked and can be easily wiped, rinsed, or otherwise freed from the liquid protective coating material, while the remaining areas are already crosslinked and firmly bonded to the substrate.

[0056] Furthermore, it is provided that at least one getter is added. A getter is essentially a reactive material that generally serves to bind unwanted substances such as water or oxygen. On the surface of a getter, gas molecules form a direct chemical bond with the atoms of the getter material, or the gas molecules are held by sorption. According to the present invention, a corresponding effect is to be achieved by introducing or adding a getter material to the protective layer to be applied, i.e., to the protective layer material. It is also provided that the getter material is applied to at least the layer stack in a separate step before the protective layer material is applied.

[0057] Such a getter can keep unwanted substances, such as penetrating moisture, away from the layer stack. This again demonstrates the superiority of the inventive method, because in a finished film, as applied as a protective layer according to the prior art, a getter material incorporated into the film would already be "consumed" before application, since the film constantly absorbs moisture and releases it to the getter. The same is true for a separately applied getter material. While the getter would then partially "dry" the damp film, it would no longer be available to absorb any additional moisture that has penetrated the film and to protect a layer stack.

[0058] One embodiment of the protective layer according to the invention provides that the functional protective layer includes, as one of its additional functions, the preparation of optical effects that take effect after encapsulation. This can, for example, include a layer that enhances light input or output. The aforementioned printing processes enable the production of a texture that supports these effects. protective layer

[0059] The object of the invention is further achieved by a protective layer for use in a continuous roll-to-roll process for the production of a semi-finished product of organic electronic components, comprising a layer stack on a substrate film. The protective layer protects the layer stack from environmental influences and damage caused by handling before and during final production. A particular advantage is that several consecutive roll-to-roll lines can be used for complete production, operated under atmospheric, inert, or low-pressure conditions as required. This reduces the complexity and size of the individual lines.For example, it is advantageous to use a roll-to-roll system for the production of the organic components and another system for their subsequent encapsulation, as the process environments of these two production steps can differ significantly. The process separation occurs, for instance, after the complete deposition and structuring of the functional organic components. The already produced layers are protected from solvents and / or mechanical stress between the work steps by the protective layer according to the invention. Furthermore, damage to the organic layer stack, which can be caused by the manufacturing-related low adhesion between the organic layer stack and the electrode during the winding and unwinding of the continuous substrate, is avoided because the protective layer prevents or hinders detachment.In accordance with the invention, it is also provided that at least one of the previously described methods is used for its production, and that the functional protective layer comprises one of the materials that meets the aforementioned requirements.

[0060] Another function of the protective layer is the complete embedding of particles and material build-up from the laser structuring, to prevent short circuit paths caused by these being pressed into the underlying organic layer stacks.

[0061] In one embodiment of the invention, the protective layer according to the invention covers the entire stack of organic layers.

[0062] In another embodiment of the invention, the protective layer does not cover the area of ​​the busbar and / or the contacts.

[0063] It is also advisable to apply an additional layer before rolling up the semi-finished product, which prevents the substrate underside of the semi-finished product roll, wound against the additional layer, from adhering to the semi-finished product roll despite longer storage times in a large roll winding.

[0064] This additional layer can be applied either permanently or temporarily. According to the invention, "temporary" means that this additional layer can be removed without leaving any residue during further processing of the semi-finished product, and that the removal of the additional layer does not cause any damage to the functional layers of the stack and / or the protective layer.

[0065] A film, for example, can be used as a temporary additional layer. Alternatively, a varnish, a material selected from the materials of the protective layer, or other transparent materials with a low affinity to the polymer substrate film can be applied as a permanent additional layer. Semi-finished product with protective layer

[0066] Another solution to the problem according to the invention is an organic electronic roll-to-roll semi-finished product on a continuous substrate with at least one optoelectronic component, comprising a substrate, an electrode arranged on the substrate, an organic layer stack and a counter electrode on the side of the layer stack facing away from the substrate, at least one photoactive organic layer between the electrode and the counter electrode, and a protective layer on the side of the at least one optoelectronic component facing away from the substrate, wherein the protective layer completely covers the organic layer stack, consists of a solvent-free, silicone-based composition which must be clear, i.e., largely transparent in the visible spectral range, and may also contain fillers, and is linked by UV or electron irradiation or thermally.is electrically insulating and is deposited in a continuous process, for example by printing, even in a vacuum.

[0067] A particularly preferred embodiment comprises, as the layer stack to be protected, an optoelectronic device, preferably an organic optoelectronic device, comprising at least two electrodes, wherein one electrode is applied to the substrate, which may include a barrier function against water vapor, oxygen, or water, and the other is applied as a counter electrode on the side facing away from the substrate, further comprising at least one photoactive layer between the electrodes. Preferably, the layer stack to be protected is produced predominantly by evaporating or sublimating small molecules with or without a carrier gas onto a substrate. The layer stack to be protected may also include further functional layers, for example, transport or passivation layers.

[0068] The invention further relates to a method for applying this protective layer, which can be integrated into the roll-to-roll production of such an organic electronic semi-finished product. Following the continuous roll-to-roll process, a transfer to a downstream machine can take place, in which further processing steps are carried out. After completion of the roll-to-roll process, only one semi-finished product is available, for example, consisting of at least three consecutive organic electronic photovoltaic and / or electrochromic modules, which were produced on a flexible substrate such as PET film using a roll-to-roll process. For the subsequent processing steps, sections of the semi-finished product of a suitable length can be used in addition to the entire roll.

[0069] The protective layer according to the invention, the roll-to-roll production process according to the invention, as well as the semi-finished product according to the invention, can also be transferred to other organic semiconducting components and their methods for production in a roll-to-roll process.

[0070] Preferably, the essential characteristics of the usable polymer composition are that it does not cause damage to the organic layers, as already described above.

[0071] The invention combines advantageous individual components, some of which are known from the prior art, in a new way, with the specific selection of these components proving particularly advantageous. This combination, in its interaction, represents a novel application of these individual components. Brief description of the drawings

[0072] Further details, features and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. These show:

[0073] Fig. 1: schematically an embodiment of a semi-finished product according to the invention in sectional view;

[0074] Fig. 2: schematically an embodiment of a plant for the production of a semi-finished product according to the invention in a roll-to-roll process;

[0075] Fig. 3: schematically an embodiment of the inventive method with application of the protective layer material by a printing device and subsequent crosslinking;

[0076] Fig. 4: schematically an embodiment of the inventive method, wherein a special topography is achieved;

[0077] Fig. 5: schematically a semi-finished product in which the protective layer has interruptions for electrical contact;

[0078] Fig. 6: schematically the application of an additional layer between the layer stack and the protective layer to incorporate further additional functions into the semi-finished product or to improve the adhesion of the protective layer to the layer stack;

[0079] Fig. 7: schematically the application of an additional layer to the protective layer to reduce unwanted damage during the rolling up and down of the semi-finished product;

[0080] Fig. 8: schematically a combination of Fig. 6 and Fig. 7

[0081] Fig. 9 and Fig. 10: schematically the application of a protective layer without or including the busbars;

[0082] Fig. 11: schematically a variant of applying a temporary additional layer to the protective layer;

[0083] Fig. 12 and Fig. 13: Scanning electron microscope images of applied protective materials on layer stacks with laser-processed electrodes;

[0084] Fig. 14: schematically comparing height compensation and smoothing by the applied protective layer on a stack of layers Description of the embodiments

[0085] Fig. Figure 1 schematically shows an embodiment of a semi-finished product according to the invention. 1 in sectional view, where a substrate 2 It is recognizable on which a layer stack 3 , which forms an organic electronic component. Both are coated with the protective layer. 4 covered up.

[0086] It becomes apparent here that the protective layer according to the invention can already be applied without further ado. 4It offers advantages over the conventional protective layer applied as a separate film. For example, the edges of the layer stack are 3 completely free of the protective layer 4 enclosed, as these also form the edge of the layer stack 3 It flows around the surface. This ensures better stability of the layer stack. 3 on the substrate 2 and prevents the layer stack from separating. 3 from the substrate 2 , for example when rolling up and unrolling.

[0087] Fig. Figure 2 schematically shows an embodiment of a plant for the production of a semi-finished product according to the invention. 1 in a roll-to-roll process. The substrate is... 2 on a roll 10 rolled up and therefore runs almost continuously into the closed system 20One. There, the layer stack for manufacturing the electronic component is formed according to the technological specifications and under the required conditions. Preferably, the layer stack is manufactured 3 under vacuum, so that in the system 20 There is very low pressure.

[0088] The semi-finished product thus created 1 will be applied to the role 11 wound up. This allows the semi-finished product to be wound up. 1 further processing, possibly in sections, is carried out. Because of the protective layer provided by the invention, the semi-finished product... 1 neither by rolling it onto the roll 11 , nor damaged by contact between surfaces. The protective layer on the semi-finished product prevents both. 1 .

[0089] Fig. Figure 3 schematically shows an embodiment of the inventive method with application of the protective layer material. 5 by a pressure device 6 and subsequent networking to produce a semi-finished product 1 The printing device 6 is particularly preferred as a wide slot die, as shown here. The substrate film moves in this process. 2 with the previously formed layer stack 3 in feed direction 8 under the pressure device 6 through. Meanwhile, the pressure device releases 6 continuously a surge of protective coating material 5 across the entire processing width, which thereby affects the substrate film 2 with the layer stack 3 overdraws.

[0090] This allows protection across the entire width of the substrate. 2 the protective layer material 5can be applied. This ensures efficient process control, high productivity, and uniform formation of the protective layer. 4 .

[0091] So that the liquid, for example monomeric, protective layer material 5 a solid protective layer 4 For the formation of a cross-linked structure, curing requires cross-linking. According to the preferred embodiment of the process, this cross-linking is induced by UV radiation, which is supplied by a cross-linking device. 7 releases when the protective layer material is 5 It is a polymer material that can be crosslinked by UV radiation, which is the preferred material. The crosslinking device 7 is adjacent to the printing device 6 arranged.

[0092] In one embodiment of the inventive method, the entire width of the resulting protective layer is exposed simultaneously. However, other forms of exposure are also provided, which, for example, offer the possibility of local omissions by means of an exposure perpendicular to the feed direction. 8 movable networking device 7 or by the separate controllability of individual UV light sources on the strip-shaped crosslinking device 7 .

[0093] Fig. Figure 4 schematically shows an embodiment of the method according to the invention, whereby a special topography is achieved. Over the layer stack 3 A protective layer will be applied 4 using the printing device 6 , which is the protective layer material 5 The coating is applied in a sufficient thickness. Curing is then carried out using the crosslinking agent, which is not visible here.

[0094] The special feature here, however, is that above the substrate 2 , where there is no layer stack 3 The protective coating material is applied in such a quantity and thickness as to compensate for the height difference. The result is a uniform, level surface of the protective coating. 4 , regardless of whether only the substrate 2 or the layer stack 3 is located under the protective layer.

[0095] According to the illustrated embodiment of the pressure device 6 , a wide slot nozzle, the slot must be modified accordingly and be inhomogeneous so that it forms a thinner protective layer in a central area 4 causes, but thicker protective layers in the peripheral areas 4 leaves behind. The design of the printing device also offers a good way to achieve such or other inhomogeneous topography. 6as a printhead, as shown in the following Fig. 5 is shown.

[0096] Fig. Figure 5 schematically shows a semi-finished product 1 , in the feed direction 8 is carried through a production facility and in which the protective layer 4 exhibits breaks that affect electrical contact points 9 This serves the purpose of creating a conductive connection for later contacting of the finished component. The production of the protective layer 4 This is done by means of a printhead that controls the printing device 6 forms. This moves perpendicular to the feed direction. 8 of the substrate 2 .

[0097] The printing device can be used in this process. 6 not only a topography similar to that in Fig. not only the 4 depicted, but also individual points, such as the contact point. 9, excluding from the coating with the protective layer material. In the preferred embodiment, the printing device has 6 at the same time the networking facility 7 so that the application and networking of the protective layer 4 can be done in one step.

[0098] Fig. Figure 6 schematically shows an embodiment of a semi-finished product according to the invention. 1 in sectional view, where a substrate 2 It is recognizable on which a layer stack 3 , which forms an organic electronic component, is structured and includes an additional layer Z1. Everything is covered with the protective layer. 4 The additional layer Z1 fulfills an additional function outside the electrical functionality of the electronic component, e.g., getter action, light coupling, or adhesion between the electrode and the protective layer. 4 .

[0099] Fig. Figure 7 schematically shows an embodiment of a semi-finished product according to the invention. 1 in sectional view, where a substrate 2 It is recognizable on which a layer stack 3 , which forms an organic electronic component. Both are coated with the protective layer. 4 The protective layer is covered by an additional layer Z2, which in turn is covered by an additional layer Z2. This additional layer has a further function to complement the protective layer's properties, for example, to promote adhesion for a subsequent lamination process of a barrier film, or to deposit encapsulation layers to complete the semi-finished product, or to add a non-stick layer to improve the winding and unwinding of the semi-finished product or its storage in the wound state. Depending on the specific design, the additional layer Z2 can be either a deposited layer or a temporary release film. 401 represent.

[0100] Fig. Figure 8 shows a schematic representation of a semi-finished product 1 in sectional view, where a substrate 2 It is recognizable on which a layer stack 3 , which forms an organic electronic component, and includes an additional layer Z1. Everything is covered with the protective layer. 4 covered, which in turn is covered by an additional layer Z2. The properties of the additional layers Z1 and Z2 are exemplified in the explanation of Fig. 6 and Fig. 7 described.

[0101] Fig. Figure 9 schematically shows an embodiment of a semi-finished product according to the invention. 1 in cross-sectional view, wherein a substrate with a conductive electrode 201 It is recognizable that a layer stack structured with the aid of lasers is present. 301(The laser structuring is indicated by small "v" shapes on the surface of the layer stack), which forms an organic electronic component, on whose surface material deposits and / or particles are present due to the laser structuring and other process properties. Furthermore, a busbar 40 applied for contacting the organic electronic component. The protective layer 4 In this case, it is applied in such a way that at least the functional and structured organic area of ​​the semi-finished product is covered.

[0102] Fig. Figure 10 schematically shows an embodiment of a semi-finished product according to the invention. 1 in sectional view, wherein a substrate with optional barrier and with conductive electrode 201 It is recognizable that a layer stack structured with the aid of lasers is present. 301, which forms an organic electronic component, on whose surface material deposits and / or particles are present due to laser structuring and other process properties. In addition, a busbar 40 applied for contacting the organic electronic component. The protective layer 4 In this case, it is applied in such a way that both the functional organic area and the busbar are covered. According to Fig. 5. Individual areas on the busbar can be kept free for later contact.

[0103] Fig. Figure 11 schematically shows another embodiment of a plant for the production of a semi-finished product according to the invention. 1 in the role-to-role procedure according to Fig. 2. The one in the appendix 20 created semi-finished product 1 In this embodiment, it is combined with an additional layer Z2, which in this case consists of a separate film.401 is formed, wound up.

[0104] Fig. Figure 12 shows a scanning electron microscopy image of a semi-finished product according to Fig. 9. Shown is a section showing a laser-structured electrode layer. The application of high energy to separate the electrode causes it to bend slightly. It can be seen that the protective layer 4 The solution flows perfectly around the protruding electrode edge, and the subsequent cross-linking leads to a fixation of the electrode protrusion. It is evident to a person skilled in the art that the protrusions are embedded in a protective layer that is initially liquid. 4 This is advantageous compared to the use of a polymer film according to the prior art, since with the latter there is a risk that the ridges will be pressed against the organic layer stack and thus lead to undesirable short-circuit paths.

[0105] Fig. Figure 13 shows another scanning electron microscopy image of a semi-finished product according to Fig. 9. Another section showing a laser-structured electrode layer is visible. The high energy input used to separate the electrode causes it to bend slightly. Additionally, a piece of the electrode, cut out from somewhere within the laser channel, remains on the component. It can be seen that the protective layer 4The coating has once again flowed perfectly around the protruding electrode edge and, moreover, fixed the detached electrode fragment that remained on the component. The advantage of using a protective layer that is very thick and initially fluid compared to the layer stack of the organic electronic component is immediately apparent to anyone skilled in the art. In subsequent processing, a surface smoothed in this way is much easier to handle and significantly reduces the technological challenges for the following processes.

[0106] Fig. Figure 14 illustrates the two properties of height equalization and smoothing of the layer stack. It is clearly visible that a substrate is present in both illustrations. 2 on which a layer stack 3 The one is arranged with a protective layer 4is covered. In leveling (a), a clearly recognizable planar semi-finished product with a protective layer is obtained. In contrast, in smoothing (b), a protective layer of approximately the same thickness is applied, so that all unevenness is covered. Reference symbol list 1 semi-finished product 2 Substrate / substrate film with optional barrier function 201 Substrate with optional barrier function and conductive electrode 3 layer stacks 301 laser-structured layer stack with material protrusions 4 protective layers 401 temporary protective film Z1 Additional layer 1 Z2 Additional layer 2 5 Protective layer material 6 Printing device 7 Networking facility 8 Feed direction 9 Contact point 10 rolls (substrate) 11 rolls (semi-finished product) 20 Annex 40 busbar QUOTES INCLUDED IN THE DESCRIPTION

[0107] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0108] US 7825326 B2

[0006] EP 2385556 A1

[0006] WO 2004083958 A2

[0010] WO 2006092135 A1

[0010] WO 2006092134 A1

[0010] EP 10725079 A1

[0010] WO 2010139804 A1

[0010] WO 2011064330 A1

[0010] DE 102012106607 A1

[0014] DE 102004024461 A1

[0016] DE 102011075081 A1

[0016] DE 102010014299 A1

[0016] DE 102008026216 B4

[0018] DE 102009025123 A1

[0018]

Claims

[1] Method for applying a protective layer ( 4 ) within the framework of a continuous roll-to-roll process for the production of a semi-finished product ( 1 ) organic electronic components comprising a layer stack ( 3 ) on a substrate film ( 2 ) optionally with barrier function, wherein the protective layer ( 4 ) the layer stack ( 3 ) protects against environmental influences and damage caused by handling before and during final production, characterized by that by means of an application through a fluid, crosslinkable or curable material that is at least temporarily fluid during the application phase and compatible with the layer stack ( 3 ) protective layer material compatible in fluid and solid phases as well as with the conditions during the roll-to-roll process ( 5 ) is applied in such a way that a functional protective layer is formed ( 4 ) forms, whereby the liquid protective layer material ( 5) is water- and solvent-free. [2] Method according to claim 1, wherein the functional protective layer ( 4 ) with a thickness of at least 50 nm and at most 200 µm. [3] Method according to any of the preceding claims, wherein the functional protective layer ( 4 ) with a thickness of at least 5 µm and at most 100 µm. [4] Method according to any of the preceding claims, wherein the application of the protective layer material ( 5 ) in a printing process. [5] Method according to claim 4, wherein the printing method comprises at least one of the methods screen printing, flexographic printing, plotting or inkjet printing or a method suitable for 3D printing and the crosslinking or curing of the protective layer material ( 5 ) includes at least one of the processes UV crosslinking, thermal crosslinking, cooling and drying. [6] Method according to claim 4, wherein for the application of the protective layer material ( 5 ) a slot nozzle is provided, followed by a crosslinking process which includes one of the following methods: UV crosslinking, thermal crosslinking and drying. [7] Method according to any one of the preceding claims, wherein the protective layer material ( 5 ) is free of water and solvents in its liquid state and has a vapor pressure that is below the ambient pressure provided for in the manufacturing process. [8] Method according to claim 7, wherein at least one of the material groups thermoplastics, thermosets or elastomers is used as the protective layer material ( 5 ) is planned. [9] Method according to claim 7, wherein at least one of the material groups phenolic resins, amino resins, unsaturated polyester resins, vinyl ester resins, epoxy resins, silicone resins, dicyclopentadiene, or diallyl phthalate resins is used as the protective layer material ( 5) is planned. [10] Method according to claim 7, wherein the protective layer material ( 5 ) aromatic, aliphatic, halogen-free or halogenated polyolefins; aromatic, aliphatic, saturated or unsaturated polyesters; polyamides, epoxy resins, epoxysiloxanes, polyurethanes, phenol-formaldehyde resins or poly(organo)siloxanes. [11] Method according to claim 7, characterized by that at least one protective layer material used ( 5 ) is prepolymerized to achieve a specific minimum or maximum viscosity. [12] Method according to claim 7, wherein the protective layer material ( 5 ) a minimum viscosity of approximately 10 mPa·s, preferably of approximately 10 2 mPa·s. [13] Method according to any one of claims 7 to 12, wherein a combination of several materials of the material groups mentioned in any one of claims 7 to 12 is used as the protective layer material. [14] Method according to one of the preceding claims, characterized in that, after the application of the functional protective layer ( 4 ), an additional layer (Z2) on the functional protective layer ( 4 ) is applied so that the functional protective layer ( 4 ) during further processing of the semi-finished product, it does not deviate from the layer stack ( 3 ) dissolves or acts as a subsequent bonding agent in encapsulation. [15] Method according to claim 15, wherein the material of the additional layer (Z2) is selected from the material groups corresponding to the protective layer material ( 5 ) is selected. [16] Method according to claim 15, wherein the material of the additional layer (Z2) is applied as a transparent or semi-transparent material. [17] Method according to claim 15, wherein the additional layer (Z2) is a temporary film ( 401) is applied, and can be removed without residue before further processing to a later state, whereby the layer stacks ( 3 ) is not damaged during unwinding, preferably as a removable material, for example a film. [18] Method according to any of the preceding claims, wherein busbars are applied before or after the application of the protective layer ( 4 ) are applied. [19] Method according to any of the preceding claims, wherein the functional protective layer ( 4 ) at least one of the additional functions height compensation with the layer stack ( 3 ), smoothing the layer stack ( 3 ), improved adhesion of an encapsulation and keeping contact points clear ( 9 ) fills or adds or in a previous process step at least onto the layer stack ( 3 ) has applied getter material. [20] Method according to any one of the preceding claims, wherein the semi-finished product ( 1 ) is an organic optoelectronic component. [21] Method according to claim 20, wherein the semi-finished product ( 1 ) is an organic optoelectronic device, preferably an organic photoactive device, with a stack consisting of several layers, wherein at least the photoactive layer or layers consist partially or completely of small organic molecules, which are preferably applied by evaporation. [22] Method according to claim 20, wherein the functional protective layer ( 4 ) as additional functions includes the preparation of optical effects that take effect after encapsulation. [23] Method according to any one of the preceding claims, wherein the protective layer material ( 5 ) is applied under negative pressure, preferably in a vacuum. [24] Protective layer ( 4) for use in a continuous roll-to-roll process for the production of a semi-finished product ( 1 ) organic electronic components comprising a layer stack ( 3 ) on a substrate film ( 2 ) optionally with barrier function, wherein the protective layer ( 4 ) the layer stack ( 3 ) protects against environmental influences and damage caused by handling before and during final production, characterized by that the functional protective layer ( 4 ) comprises a material applied according to one of the preceding claims. [25] Protective layer according to claim 24, wherein the protective layer completely covers the organic layer stack. [26] Protective layer according to claim 24, wherein the protective layer does not cover the areas of the busbar and / or the contacts. [27] Protective layer ( 4) according to one of claims 24 to 26, wherein a further material (Z2) is applied to the protective layer. [28] Organic electronic roll-to-roll semi-finished product ( 1 ) on a continuous substrate ( 2 ) comprising at least one optoelectronic component, a substrate ( 2 ) with optional barrier function, one on the substrate ( 2 ) arranged electrode, an organic layer stack ( 3 ) and a counter electrode on the substrate ( 2 ) far side of the layer stack ( 3 ), at least one photoactive organic layer between the electrode and the counter electrode, and a protective layer ( 4 ) on the substrate ( 2 ) opposite side of the at least one optoelectronic component, characterized by that the protective layer ( 4 ) the organic layer stack ( 3) completely or to the extent that only the contacts are not uncovered, whereby the protective layer material ( 5 ) consists of a water- and solvent-free composition, which can be both clear and transparent and may contain fillers, and is linked by UV, electron irradiation or thermally, acts as an electrical insulator and is deposited in a continuous process [29] Organic electronic roll-to-roll semi-finished product ( 1 ) according to claim 28, characterized by that the optoelectronic device is an organic optoelectronic device comprising a layer stack with at least two electrodes, further comprising at least one photoactive layer, preferably as an organic photoactive layer, between the electrodes, wherein the layers are preferably applied by evaporating small organic molecules.

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