Imprint-free and residue-free patterned substrate

Abstract

This disclosure relates to a patterned substrate having a surface relief structure comprising a plurality of isolated and laterally separated elements of a cured polymer composition. This disclosure further relates to a stamp, system, and method of manufacture. The method comprises the steps of providing a stamp (10), depositing a fluid photocurable layer (50) onto a carrier substrate, imprinting the layer by pressing the stamp into the layer (P), selectively curing the photocurable layer while imprinting by irradiating the photocurable layer with light (L) to form a relief structure, and removing any uncured residue of the photocurable layer, if present, from the stamp and / or carrier substrate, wherein the stamp projection comprises an opaque cap (13) extending along the end face (14) of the projection, the cap comprising a polymer or composite material, preferably an elastomer or elastomer composite material.

Description

Technical Field

[0001] The present disclosure relates to a patterned substrate, specifically a substrate with a relief structure formed thereon, the relief structure comprising a plurality of isolated, laterally separated elements of a cured polymer composition. The present disclosure further relates to manufacturing stamps, systems, and methods.

Background Art

[0002] Substrates having surface relief can be used in many fields. For example, in optics (as filters), or as a scaffold for the assembly of functional multilayer structures such as 3D electrodes.

[0003] Imprinting, such as thermal imprinting which uses a heated stamp in combination with pressure, is a known method employed to impart the negative of a stamp into a thermoplastic. Alternative imprinting methods include so-called forward and reverse nanoimprinting, which typically involve supplying a curable resist between the stamp and the substrate, then curing the resist and removing the stamp.

[0004] Korean Patent Publication No. 20080098212 discloses a method involving a hard-coated stamp for providing a patterned substrate. An additional developing step is required to remove residues from the patterned substrate.

[0005] Korean Patent Publication No. 20090070946 relates to a method of reverse-imprinting a resist to provide a patterned substrate. This process requires an inhibitor coat provided at a specific position between the substrate and the resist.

[0006] Japanese Patent Publication No. 2010-158805 describes an optical imprint mold having a light-shielding film at the tip of the protruding portion of the mold. Etching with a developer is performed to remove the uncured resin between the protruding portion of the mold and the substrate.

[0007] While known processes can provide patterned substrates, there remains a need for processes that are more robust, more durable, involve fewer processing steps, and / or form substrates with less or no residue between adjacent relief elements. There also remains a need for processes that allow any residue that may be present between adjacent relief elements to be removed more easily and / or without damaging the substrate. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Korean Published Patent Publication No. 20080098212 [Patent Document 2] Korean Published Patent Publication No. 20090070946 [Patent Document 3] Japanese Patent Publication No. 2010-158805 [Non-patent literature]

[0009] [Non-Patent Document 1] Serra et al., Advanced Materials Technologies 2018, 4, 1800099 [Overview of the project] [Means for solving the problem]

[0010] Aspects of this disclosure relate to patterned substrates and methods for manufacturing the desired patterned substrate described above.

[0011] The substrate includes a carrier substrate on which a relief structure is formed, the relief structure comprising a plurality of isolated and laterally separated relief elements. The relief elements are formed from a cured composition, typically a polymer composition or a composite composition comprising a polymer matrix. The carrier substrate can be selected from a wide range of substrates, but is not limited to polymer substrates, semiconductor substrates, metal substrates, composite materials, and multilayer substrates. The cured relief can advantageously be used as a scaffold for one or more functional layers.

[0012] As will become apparent from this specification below, various substrates, including conductive substrates such as metals or metal-coated substrates, can be particularly beneficial in the manufacture of current collectors / current injectors. For example, substrates can provide electrodes (e.g., for batteries) that, among other things, provide a 3D patterned scaffold for (battery) functional materials that increases area and / or enhances current collection ability and increases surface area.

[0013] Advantageously, the substrate can be a flexible or rollable substrate. In preferred embodiments, the carrier substrate includes a flexible metal foil, or a flexible foil having a metal coating, such as copper foil, aluminum foil, or metal-coated plastic foil (e.g., PET or PEN). Alternatively, or in addition, the carrier substrate may be a polymer film on which an optional additional layer is deposited.

[0014] Advantageously, and particularly in relation to electrical applications, the carrier substrate surfaces between laterally separated protrusions may be directly accessible or, conversely, essentially free of coatings or residues from the relief manufacturing process. Removal of uncured residues from the carrier substrate surfaces between laterally separated protrusions may, if necessary, be advantageously carried out without damaging the carrier substrate and / or the laterally separated protrusions. Reducing or, conversely preventing, the presence of layers / residues that interfere with direct, electronically conductive contact with the substrate can improve performance, for example, as a current collector.

[0015] In a preferred embodiment, the substrate further includes a metallic topcoat. The topcoat is shape-conformably disposed on the polymer scaffold and can extend along the surface of the carrier substrate between laterally separated protrusions. This coating enhances the current collection / current injection area and the uniformity of current collection.

[0016] In another, or further preferred embodiment, the substrate may be what is referred to herein as a double-sided coated substrate. Double-sided coated substrates can be advantageously used in stacking and / or double-sided electrode applications, for example, in battery cell stacks. A double-sided coated substrate includes an additional second relief structure formed along the surface of the carrier substrate opposite to the first relief structure. Referring to a method for manufacturing a substrate as described below, the relief structure on the opposite side of the double-sided coated structure can be manufactured sequentially and / or simultaneously on both sides.

[0017] Substrates may be manufactured by methods using materials and systems as detailed herein. In particular, methods / systems as described enable processing of substrates under mild conditions, for example, without the possibility of contamination by developer and / or inhibitor residues as described in Korean Published Patent No. 20080098212, Korean Published Patent No. 20090070946, and Japanese Patent Application Publication No. 2010-158805. In addition, processes as described can reduce or prevent substrate degradation / etching by eliminating the need for oxidizing and / or etching agents (e.g., strong acids or bases) to remove residues.

[0018] In a further embodiment, a method is provided for manufacturing a substrate including a carrier substrate having a relief structure, preferably a patterned substrate as disclosed herein. The method includes at least i) providing a stamp having a plurality of transversely separated upright stamp projections extending from a stamp base. The stamp projections form the negative of the relief structure. In addition, the method includes ii) depositing a fluid photocurable layer on the carrier substrate. This composition may be a photocurable resist or composite material as known in the art. Alternatively, or in addition, the composition may include a thermosetting composition. With respect to thermosetting compositions, it will be understood that curing may be caused by heat, such as conductive heat or radiant heat (such as IR).

[0019] iii) After the layer is formed, there is a step of imprinting the photocurable layer. Imprinting involves pressing the stamp into the layer and bringing the tip of the stamp projection into contact with the carrier substrate, thereby displacing the fluid curable composition at a position between the substrate and the tip of the stamp projection. By bringing the tip of the stamp projection into contact with the carrier substrate, most or even substantially all of the fluid curable composition is displaced from the space between the tips of the stamp projections toward the recesses between adjacent stamp projections. Thus, apart from a very small amount of residue, there is no fluid curable composition between the substrate and the tip of the stamp projection during curing. There is a step of selectively curing the composition while the stamp is in contact with the layer. Curing may include irradiating the photocurable layer with light to form a relief structure. Advantageously, exposure may be performed through the stamp.

[0020] The stamp projection includes an opaque cap extending along the end face at the tip of the stamp projection, and the cap comprises a polymer or composite material, preferably an elastomer or an elastomer composite material. Providing the opaque cap can advantageously shield the material between the stamp tip and the substrate from curing if there is any material there. Preferably, the base and projection of the stamp are formed from a flexible elastic composition.

[0021] After curing, step v) of removing the stamp from the carrier substrate and the formed relief structure follows. Process steps (ii to v) can then be repeated on a different substrate or on a different section of the same substrate.

[0022] After removing the stamp, there may be a step vi) of removing any uncured residue of the photocurable layer from the stamp and / or the carrier substrate. Since the areas between the reliefs are shielded from photocuring in this process, the residue can be successfully removed, if any, without damaging the cured reliefs, for example using a solvent exposure / washing step. If necessary, the residue can be removed in alternative steps including, but not limited to, etching.

[0023] In addition to the method for manufacturing patterned substrates described above, which may be referred to as forward imprinting, further processes based on reverse imprinting are provided. Processes and systems based on reverse imprinting, as described herein, advantageously provide an alternative route for manufacturing substrates, thereby reducing the level of residue using the same general concepts as forward imprinting. Alternatively, or in addition, the use of reverse imprinting may reduce the amount of curable composition used. Advantageously, the stamping and processing systems may be as described, and it will be understood that, unless otherwise specified, further descriptions of features may apply to both forward imprinting and reverse imprinting processes and systems. This method based on reverse imprinting includes the steps of: a) providing a stamp having a plurality of laterally separated upright stamp projections extending from the surface of the stamp base; b) filling the recesses between the laterally separated upright stamp projections with a fluid photocurable composition; c) reverse imprinting the photocurable layer, wherein the stamp is pressed into the carrier substrate to bring the tips of the stamp projections into contact with the carrier substrate, thereby bringing the fluid photocurable composition into contact with the carrier substrate; d) selectively curing the photocurable composition while reverse imprinting, wherein light is irradiated onto the photocurable composition through the stamp, thereby transferring the fluid photocurable composition from the recesses and forming a relief structure; e) removing the stamp from the carrier substrate and the formed relief structure; and f) removing any uncured residue of the photocurable layer, if present, from the stamp and / or carrier substrate. Similar to the forward imprint method, the stamp projection includes an opaque cap extending along the end face of the tip of the stamp projection, the cap comprising a polymer or composite material, preferably an elastomer or elastomer composite material. The opaque cap advantageously shields any material between the stamp tip and the substrate from curing. Preferably, the base and projection of the stamp are formed from a flexible elastic composition.

[0024] The combination of contacting the tip of the stamp protrusion with the carrier substrate and providing an opaque cap at the tip of the stamp protrusion (for both forward and reverse imprinting) is particularly advantageous for forming a residue-free region between horizontally separated protrusions as compared to processes in which only one of these approaches is used. The inventors have found that when a substantial amount of curable composition is present between the tip of the protrusion and the carrier substrate (i.e., when the tip of the stamp protrusion is not in contact with the carrier substrate), even if the stamp protrusion is shaded, photocuring of the material between the tip of the protrusion and the substrate still occurs to some extent. This photocuring is caused, for example, by reflection of the curing radiation by the carrier substrate, diffuse reflection from adjacent regions of the curable composition, and / or stray light that reaches the space between the tip of the shaded stamp protrusion and the carrier substrate due to shading that does not completely block the curing radiation. Thus, such unintentional photocuring of the material between the stamp tip and the substrate poses a problem for the removal of this “uncured” material (i.e., material that has been unintentionally cured to some extent). Additional cleaning steps and / or corrosive chemical processes such as etching may be required for removal, thereby increasing the likelihood of damaging the cured relief and / or the carrier substrate.

[0025] In some embodiments, the cap is a composite with one or more additives, such as metals, ceramic particles or other particles (e.g., carbonaceous particles), added to a polymer matrix to improve opacity.

[0026] Since the stamp and cap are polymer-based or at least polymer-based compositions, the stamp can provide a highly conformable contact with the substrate when pressed onto it, by adapting to elastic deformation, in contrast to rigid stamps. In addition, further in contrast to rigid stamps, the stamps according to this disclosure can be applied to more durable and / or relatively brittle / sensitive substrates.

[0027] In some embodiments, the cap is limited to the end face / tip of the projection. In other or further embodiments, the cap partially extends along the side wall of the stamp projection. Partially coating the side wall of the stamp projection has been found to improve pattern clarity, for example, by blocking reflection / stray light.

[0028] In one preferred embodiment, the cap has higher rigidity than the stamp projection. Alternatively, or in addition, the cap may have higher hardness than the projection. The inventors have found that when the stamp has relatively lower rigidity and / or hardness than the cap, for example, the squeezing of the curable composition from beneath the cap is improved, so pattern clarity can be further improved with even less or no residue. In addition, the stress on the cap can be reduced, which can improve durability / operational life.

[0029] In some preferred embodiments, the photocurable composition is heated, for example, by radiation (e.g., IR) or conductivity, before and / or during imprinting. It has been found that heating the photocurable composition improves pattern clarity due to improved fluidity (decreased viscosity) and increased curing rate.

[0030] In some embodiments, the layers of the photocurable composition have a viscosity that decreases toward the carrier substrate. In this way, preferably in the case of forward imprinting, the material between the stamp protrusions can be squeezed out more effectively. Viscosity gradients can be achieved by depositing layers of photocurable compositions having different viscosities, for example, multilayer stacks. Alternatively, or in addition, a viscosity gradient in which the viscosity decreases toward the carrier substrate can be achieved by applying a temperature gradient to the layers of the photocurable composition in which the temperature increases toward the carrier substrate. Such a temperature gradient can be achieved, for example, by heating the photocurable composition from the direction of the carrier substrate before and / or during imprinting.

[0031] Similarly, in some embodiments, the flowable photocurable composition between stamp protrusions has a viscosity that increases toward the carrier substrate. Thus, although preferably related to reverse imprinting, the transfer of the photocurable composition from the stamp to the carrier substrate can be performed more effectively. The viscosity gradient can be achieved, for example, by filling the stamp recesses with layers of photocurable compositions having different viscosities, e.g., multilayer stacks. Alternatively, or in addition, a viscosity gradient in which the viscosity increases toward the carrier substrate can be achieved by applying a temperature gradient to the photocurable composition layers in which the temperature decreases toward the carrier substrate. Such a temperature gradient can be achieved, for example, by heating the photocurable composition from the direction of the stamp before and / or during imprinting.

[0032] In other or further embodiments, the steps under iii), iv) and optionally v), or in the case of reverse imprinting, the steps under c), d) and optionally e), are performed at a pressure lower than atmospheric pressure. Working at a pressure lower than atmospheric pressure can improve stamp / substrate contact and reduce the content of volatile substances in the curable composition (e.g., by removing dissolving gases).

[0033] In some preferred variations, the photocurable composition typically contains 1 to 10% by weight of an organic solvent. The inventors have found that the addition of a solvent, preferably a volatile organic solvent, can favorably induce a controllable amount of shrinkage during curing, which can be advantageous for removing the stamp.

[0034] The methods / process steps disclosed herein are not limited to rigid substrates (e.g., Si wafers). Advantageously, the carrier substrate can be an elongated web, preferably a flexible metal foil or a flexible metal-coated foil. Furthermore, in the case of forward imprinting, one or more, preferably all, of the steps of depositing a fluid photocurable layer, imprinting the photocurable layer, selectively curing the photocurable layer, removing the stamp, and removing any uncured residue of the photocurable layer may be embodied as a roll-to-roll process. Similarly, in the case of reverse imprinting, one or more, preferably all, of the steps of filling the recesses with a photocurable composition, reverse imprinting the photocurable composition, selectively curing the photocurable composition, removing the stamp, and removing any uncured residue of the photocurable layer may be embodied as a roll-to-roll step.

[0035] In some variations, the method may further include a step of coating the substrate with an adhesion-promoting layer. Depending on the properties of the carrier substrate (e.g., type of metal), adhesion promotion may be achieved by one or more of the following: self-assembled monolayers (SAMs: including, but not limited to, silanes, thiols, etc., which may be applied using, e.g., CVD), mild oxidation steps (including, but not limited to, UV / ozone, plasma, etc.), and deposition of metals and / or metal oxides (PVD, sputtering, etc.). If the patterned substrate is used for electrical applications (e.g., current collectors), it will be understood that the adhesion-promoting layer is configured to provide conductive paths in the substrate. In preferred variations, the adhesion-promoting layer includes a metal layer (e.g., a metal relatively nobler than the carrier substrate, such as gold) or a metal oxide (e.g., conductive metal oxides such as titanium nitride, zirconium nitride, and / or indium tin oxide), which can act as barriers (e.g., etch stops / sputter stops) in removing any uncured residues of the photocurable layer, if any.

[0036] If the adhesion-promoting layer is chemically inert to the carrier substrate and is provided between the carrier substrate and the relief structure, the adhesion-promoting layer can reduce or even avoid the reaction between the carrier substrate and the photocurable material of the relief structure, whereas in its absence, oxidation of the carrier substrate, for example, may occur. In this regard, preferred materials for the adhesion-promoting layer include ceramic materials such as titanium nitride, zirconium nitride, and / or indium tin oxide, or precious metals (e.g., gold).

[0037] In a further embodiment, an electrode is provided comprising a substrate including a carrier substrate and a relief structure as described herein. In the case of an electrode, the carrier substrate is preferably conductive so as to be able to act as a current collector. In addition to the substrate as described herein, the electrode may comprise additional layers on the substrate, such as a conductive layer to facilitate the transport of electrons from the relief structure to the carrier substrate, a passivation layer to prevent degradation of the active electrode material, a seed layer to facilitate the deposition of the active electrode material, a host layer for the active electrode material, and / or an SEI layer. The electrode may be an anode and / or cathode. Advantageously, the absence of residue on the surface of the carrier substrate between the upright protrusions allows for good contact (e.g., electrical contact and / or mechanical contact) between the carrier substrate and any layer that may be deposited on the carrier substrate between the protrusions of the relief structure.

[0038] Furthermore, an energy storage device (e.g., a battery) is provided, which includes one or more electrodes as described above and an electrolyte.

[0039] In a further embodiment, a stamp is provided for use in a manner such as that disclosed herein. Unless otherwise apparent from the context, the stamp comprises a stamp base having a surface provided with at least a plurality of transversely separated upright stamp projections, the stamp being provided with one or more opaque caps each extending along the end faces of the tips of the stamp projections, the caps being formed from a polymer or composite material, preferably an elastomer or elastomer composite material. Preferably, the stamp base and projections are optically transparent. This allows exposure of the photocurable composition from the stamp direction during imprinting. Exposure of the photocurable composition from the stamp direction allows the use of an opaque substrate. For example, exposure from the stamp direction allows curing of a layer of photocurable composition on, for example, a metal or metal coating foil, with the stamp in coplanar contact.

[0040] Preferably, the stamp is formed from a flexible composition. This allows the stamp to be placed outside the rollers for roll-to-roll processing. The stamp may be, for example, located outside a (single) roller or suspended between two or more rollers, for example, in the form of a belt. The advantage of providing the stamp as a belt suspended between two or more rollers compared to outside a single roller includes the possibility of conveniently scaling up the process and / or adjusting the (forward and / or reverse) imprint time. In addition, providing the stamp as a belt between two or more rollers may allow more space for additional equipment to be located on the side of the stamp, such as a heater, a radiation source for curing the photocurable composition, and / or a laser source for supplying pulsed laser light.

[0041] In some variations, the stamp features a metallic or ceramic coating extending over the cap or between the cap and the stamp projection. The coating may reduce the optical transparency of the stamp at the tip.

[0042] In other or further variations, the outer surface of the cap is provided with relatively higher hydrophobicity (e.g., a coating) than the outer surface of the upright stamp projection. Relatively higher hydrophobicity improves pattern clarity and reduces the possibility of residue between the tip and the substrate. Hydrophobicity can be imparted by the type of polymer and / or the selection of additives, as well as the addition of a single layer (thiol in the case of metals) silane, etc.

[0043] In a further embodiment, a method and system for manufacturing a stamp according to the present disclosure are provided. The method provides a stamp base having a surface on which a plurality of laterally separated upright stamp projections are provided, wherein the stamp base and projections are optically transparent, and provides coating the end faces at the tips of the stamp projections with an opaque cap, the coating comprising the steps of: applying a layer of a curable ink composition having an opaque quality when cured onto an applicator; transferring at least a portion of the ink to the tips; and then curing the ink.

[0044] Coating of the stamp tip can be performed by bringing the stamp into contact with an applicator, preferably an application roller, which has a layer of ink, preferably a layer having a predefined and appropriately controlled thickness. Controlling the thickness can allow for selective coating of the end face of the tip and / or partial coating of the sidewalls of the stamp projection. Thus, in some embodiments, the method further includes controlling the thickness of the layer in the applicator.

[0045] In some embodiments, the method further includes one or more steps of depositing a ceramic or metal coating before or after coating the ink. The coating may be provided by known means, but is not limited to PVD or electroplating (electroless plating).

[0046] In a preferred variation, a system configured to carry out a method for manufacturing a stamp comprises a source holding a certain amount of a curable ink composition having an opaque quality when cured, an applicator roller, and a receiver roller disposed in a reverse rotation relationship with respect to the applicator roller, wherein the applicator roller is configured to receive a film of the curable ink composition from the source along the outer surface of the applicator roller, and the receiver roller is configured to carry a stamp along its outer surface, the stamp including a stamp base having a surface provided with a plurality of laterally separated upright stamp projections, and the applicator roller and the receiver roller are positionable relative to each other so that the tips of the stamp projections contact the film of the curable ink composition.

[0047] In some embodiments, the system further comprises substantially rigid ridges positioned at a controllable separation distance from the outer surface of an applicator roller that forms slits for controlling the thickness of a film of a curable ink composition.

[0048] In a further embodiment, a system is provided configured to carry out a method for manufacturing a substrate including a carrier substrate having a relief structure as described herein, the system comprising an applicator, a stamp as described herein, a pressure system, and a curing system including a light source, wherein the applicator is configured to deposit a fluid photocurable layer onto the carrier substrate or to fill the recesses between laterally separated upright stamp protrusions with a fluid photocurable composition, the pressure system is configured to bring the tips of the stamp protrusions into contact with the carrier substrate, and the curing system is configured to irradiate the photocurable layer or photocurable composition with light during imprinting.

[0049] These and other features, aspects, and advantages of the apparatus, systems, and methods of this disclosure will be better understood by looking at the following description, the accompanying claims, and the accompanying drawings. [Brief explanation of the drawing]

[0050] [Figure 1A] This figure illustrates a method for manufacturing a substrate including a carrier substrate having a relief structure. [Figure 1B] Figure 1A illustrates the various stages of the method shown. [Figure 1C] Figure 1A illustrates the various stages of the method shown. [Figure 1D] Figure 1A illustrates the various stages of the method shown. [Figure 1E] This is a diagram illustrating a patterned substrate. [Figure 2] This is an example diagram of a stamp. [Figure 3] This diagram illustrates variations of patterned substrates. [Figure 4] This figure illustrates one embodiment of a fluid photocurable layer. [Figure 5A] This is a diagram illustrating a system for manufacturing patterned circuit boards. [Figure 5B] This figure illustrates details of system variations for carrying out a method for manufacturing patterned substrates. [Figure 5C] This figure illustrates details of system variations for carrying out a method for manufacturing patterned substrates. [Figure 6] This is a diagram illustrating a method for manufacturing stamps. [Figure 7] This diagram illustrates a system in the process of manufacturing stamps. [Figure 8A] This figure illustrates a further method for manufacturing a substrate including a carrier substrate having a relief structure. [Figure 8B] Figure 8A illustrates the various steps of the method shown. [Figure 8C] Figure 8A illustrates the various steps of the method shown. [Figure 8D] Figure 8A illustrates the various steps of the method shown. [Figure 8E] This is a diagram illustrating a patterned substrate. [Figure 9] This diagram illustrates a double-sided patterned substrate. [Modes for carrying out the invention]

[0051] The terminology used to describe specific embodiments is not intended to limit the invention. As used herein, “a,” “an,” and “the” are intended to include the plural unless the context clearly indicates otherwise. The term “and / or” includes any combination of one or more of the related enumerated items. The terms “includes” and / or “includes” will be understood to specify the presence of the described feature but not to exclude the presence or addition of one or more other features. When a particular step of a method is referred to as following another step, it will be further understood that, unless otherwise specified, it may follow immediately after the other step, or one or more intermediate steps may be performed before the particular step. Similarly, when a connection between a structure or components is described, this connection may be established directly or through an intermediate structure or component, unless otherwise specified.

[0052] The present invention is described more fully below with reference to the accompanying drawings, which illustrate embodiments of the invention. In the drawings, absolute and relative sizes of systems, components, layers, and areas may be exaggerated for illustrative purposes. Embodiments are described with reference to schematic and / or cross-sectional views of idealized embodiments and intermediate structures of the invention, if possible. In the description and drawings, similar numbers refer to similar elements throughout. Relative terms and their derivatives should be interpreted as referring to orientations as described thereafter or as shown in the drawings described herein. These relative terms are for illustrative purposes only and, unless otherwise stated, do not require the system to be manufactured or operated in a particular orientation.

[0053] Next, the patterned substrate, stamp, system, and manufacturing method will be described in more detail with reference to Figures 1 to 10. Referring to Figure 1, a method (100) for manufacturing a substrate 20 is presented. In a variation, the patterned substrate 20 includes a carrier substrate 21 on which a relief structure 22 is formed, the relief structure includes a plurality of isolated, laterally separated protrusions 23 formed from a cured polymer composition. Advantageously, the surfaces 29 of the carrier substrate between the laterally separated protrusions are essentially free from coatings or residues that would, when present, prevent direct, electronically conductive contact with the substrate.

[0054] As shown, this process Step 101, providing the stamp, Step 102 involves depositing a fluid photocurable layer 50 on a carrier substrate, Step 103 involves imprinting a photocurable layer, A step (104) in which a photocurable layer is selectively cured while imprinting, The step (105) may include removing the stamp from the carrier substrate and the formed relief structure.

[0055] Figure 1B illustrates a stamp 10 having a stamp base 12 and a plurality of stamp protrusions 11. The stamp protrusions are coated with opaque caps 13 limited to the end faces of the stamp protrusions 11. In a preferred embodiment, the caps have a transmittance of 10% or less to curing light over the wavelength range (e.g., UV) that triggers the photocuring of the fluid photocurable layer 50. Such caps may also be hydrophobic to the photocurable polymer (e.g., by monolayer coating or other means), so that they are repelled during imprinting, resulting in minimal or negligible residue on the stamp. Preferably, the transmittance is ≤5% or less, for example, having perfect reflectivity. Generally, the stamp and stamp protrusions 11 are formed from a polymer composition having high transmittance to curing light. Typically, or preferably, the transmittance of such a polymer composition is 80% or more, preferably 90% or more.

[0056] In variations, for example as shown in Figure 2, the stamp 10 may have one or more of the following: a tapered projection and a metal coating or a ceramic coating 16 which may be provided on the opaque cap 13 or between the stamp projection 11 and the cap (not shown). Alternatively, or in addition, the cap, metal coating or ceramic coating 16, and the stamp may extend along the sidewall 15 of the stamp projection 11, for example, over a length of up to 50% of the total height of the stamp projection 11. Both the additional coating and the extension along the sidewall reduce the transmittance of the stamp projection 11 and increase the pattern clarity in the imprint 103 step.

[0057] The fluid photocurable layer 50 has a thickness and / or fluidity such that, after imprinting, any excess material between the substrate and the tip flows to the side, for example, into the space between adjacent stamp protrusions 11, when pressure P is applied to the stamp.

[0058] As shown in Figure 1D, the amount of the fluid photocurable layer 50 between the substrate and the stamp projection 11 can be negligible. This ensures that, upon curing 104, the polymer relief is formed without any residue remaining on the surfaces 21s between adjacent relief structures. Even if there is still uncured residual photopolymer on the surfaces 21s between adjacent relief structures (during imprinting), it can be washed away after imprinting.

[0059] As shown in Figure 1D, curing is performed during imprinting, i.e., while the stamp projection 11 is in contact with the carrier substrate 21. After the stamp is removed, the substrate 20 is formed. As shown, the light (L) that causes photocuring can be supplied through the stamp while it is in contact with the substrate, so that the opaque cap 13 prevents / blocks any exposure of the curable material between the stamp projection 11 and the carrier substrate 21.

[0060] Figure 1E illustrates an exemplary patterned substrate obtained by the process. The patterned substrate 20 includes a carrier substrate 21 on which a relief structure 22 is formed, the relief structure includes a plurality of isolated, laterally separated relief elements 23 formed from a cured polymer composition. In one preferred embodiment (see, for example, Figure 3), the carrier substrate 21 includes a metal foil or a foil 21a having a metal coating 21b. Advantageously, the surfaces 21s of the carrier substrate between the laterally separated protrusions 23 can be free of coatings or residues that would prevent direct, electronically conductive contact with the substrate.

[0061] In some variations, the method may include one or more of the following steps: removing any uncured residue of the photocurable layer from the stamp and / or carrier substrate, if present; heating the photocurable layer before and / or during imprinting; adding a solvent to the fluid photocurable layer 50 before deposition; and coating the substrate with a conductive adhesion promoter or a conductive cover layer.

[0062] The substrate may be a multilayer substrate. Figure 3 illustrates a variation in which the substrate is a flexible polymer foil 21a having a metal coating 21, and the formed relief is provided with a metal topcoat 29.

[0063] In some embodiments, the fluid photocurable layer 50 has a viscosity that decreases toward the carrier substrate to facilitate the squeezing of the curable material from between the stamp projection 11 and the substrate. In some embodiments, as shown, for example in Figure 4, the fluid photocurable layer 50 consists of a multilayer stack formed from, for example, two, three, or more lower layers (50-1, 50-2, 50-n) whose viscosity decreases toward the substrate. For example, the lower layers may have gradually increasing levels of solvent. Alternatively, or in addition, such a viscosity gradient can also be achieved by applying a temperature gradient to the photocurable layer, for example, by heating the photocurable composition from the direction of the carrier substrate before and / or during imprinting, thereby increasing the temperature toward the carrier substrate.

[0064] In a further embodiment, a system 500 for manufacturing a patterned substrate 20 as disclosed herein is provided. The system comprises means configured to carry out a method 100 for manufacturing a substrate 20 including a carrier substrate 21 having a relief structure 22. According to this method, the system comprises at least, A means for depositing one layer of a fluid photocurable layer on a carrier substrate, Means for imprinting a photocurable layer, the means including a stamp as disclosed herein and a pressure system for pressing the stamp into the layer so as to bring the tip of the stamp projection into contact with a carrier substrate and thereby displace the layer at a position between the substrate and the tip of the stamp projection, The system includes a light source for irradiating a photocurable layer with light (L), preferably from the direction of the stamp, thereby forming a relief structure.

[0065] Similarly, for reverse imprinting, a system 600 for manufacturing a patterned substrate 20 as disclosed herein is provided. The system comprises means configured to execute a method 400 for manufacturing a substrate 20 including at least a carrier substrate 21 having a relief structure 22 as described herein. According to this method, the system comprises at least means for filling a recess between laterally separated upright protrusions of a stamp, as disclosed herein, with a flowable photocurable composition, means for reverse imprinting a photocurable layer, the means comprising a stamp as disclosed herein and a pressure system for pushing the stamp into the carrier substrate to contact the tips of the stamp protrusions with the carrier substrate, thereby contacting the flowable photocurable composition with the carrier substrate, and a curing system including a light source for performing light irradiation (L) on the photocurable composition, preferably from the direction of the stamp, thereby forming a relief structure.

[0066] In some preferred variations, the system 500 or 600 comprises one or more of means for removing, if present, uncured residues of the photocurable layer from the stamp and / or the carrier substrate, a heater system for heating the substrate and / or the photocurable material before and / or during imprinting, and a conveyor.

[0067] In a preferred embodiment, system 500 or 600 is embodied as a roll-to-roll system. Figure 5A illustrates a system that performs a method of manufacturing a patterned substrate using forward imprinting. This system includes a conveyor system, an applicator, and a patterning station 510. The conveyor system typically includes a feed roller 501 for holding a supply of substrate 20 in the form of an elongated web 21a, a retrieve roller 502 for recovering the patterned substrate 20 after processing, and preferably one or more auxiliary rollers for guiding the web past processing positions including an applicator 80, e.g., a slot die coater, configured to coat at least a layer of fluid photocurable layer 50, and the patterning station 510. If necessary, one or more means may be provided to control the thickness of the fluid photocurable layer 50 (e.g., a planaring roller or hard ridge 81 disposed as a controllable separator from the substrate (see Figure 7)). In a preferred embodiment, for example as illustrated, the patterning station includes at least a patterning roller 504. The patterning roller holds one or more stamps 10, as disclosed herein, along its outer surface. A pressure system, including, for example, a reverse-rotating roller 503 (or otherwise, for example, a compressible plate or belt configured to press the substrate and stamp toward each other), is provided so that the tip of the stamp can be pressed into the photocurable layer 50. While in contact, the curing system 82 exposes the fluid photocurable layer 50 to light (UV in the case of a UV-curable composition).

[0068] Similarly, Figure 5C shows a system for reverse imprinting (see method 400 below), including a conveyor system, an applicator, and a patterning station 610. A conveyor system, comprising a supply roller 601 and a recovery roller 602, guides the substrate 20 in the form of an elongated web 21a through the patterning station 610. The applicator 60 is configured to fill the recesses between laterally separated upright projections of a stamp 10, provided on the outer surface of the roller, with a fluid photocurable composition 50. A reverse-rotating roller is provided so that the stamp 10 is pressed onto the carrier substrate, bringing the tips of the stamp projections into contact with the carrier substrate, thereby bringing the fluid photocurable composition 50 into contact with the carrier substrate. While the tips of the stamp 10 are in contact with the carrier substrate, a curing system 82 exposes the fluid photocurable composition 50 to light (UV in the case of a UV-curable composition).

[0069] System 600 may be provided with means for cleaning the tip of the stamp protrusions before imprinting. Additionally, system 600 may be provided with means for forcing and / or dispensing the flowable photocurable composition 50 into the recesses before imprinting. The means for cleaning the tip of the stamp protrusions and the means for forcing / dispensing the flowable photocurable composition 50 into the recesses may be provided by separate components or may be combined. Preferably, such components are positionable at a controllable distance from the tip of the stamp protrusions. Suitable devices for cleaning the tip of the stamp protrusions and / or for forcing / dispensing the flowable photocurable composition 50 into the recesses may be rigid or may be flexible (e.g., a sponge or squeegee) and may be provided as a moving element (e.g., a wiping roller) or as a stationary element. An example of a stationary element that may be used for forcing / dispensing the flowable photocurable composition 50 into the recesses and / or for cleaning the tip of the stamp protrusions is a rigid ridge 62 (e.g., a doctor blade) as shown in FIG. 5C. A combination of a flexible element such as a squeegee for forcing / dispensing the flowable photocurable composition 50 into the recesses and then a rigid element such as a doctor blade for cleaning the tip of the protrusions is particularly provided.

[0070] In a particularly preferred embodiment, the curing system is integrated into the patterning station 510 or 610. In particular, in a preferred variation, the light source 82 is integrated into the patterning roller, as shown, for example, in FIGS. 5B and 5C. Integrating the light source into the patterning roller makes it possible to trigger the curing of the flowable photocurable layer 50 or the photocurable composition 50 during imprinting, whereby the region directly below / beneath the opaque cap 13 is shielded from the exposure.

[0071] Preferably, the carrier substrate (21) is an elongated web (21a), preferably a flexible metal foil or a flexible metal-coated foil, and the steps of depositing a flowable photocurable layer, imprinting the photocurable layer, selectively curing the photocurable layer, removing the stamp, and removing any uncured residue of the photocurable layer (or, similarly for reverse imprinting, the steps of filling the recesses with a photocurable composition, reverse imprinting the photocurable composition, selectively curing the photocurable composition, removing the stamp, and removing any uncured residue of the photocurable composition) are implemented along a roll-to-roll processing line (500 or 600).

[0072] Figures 6 and 7 illustrate, respectively, a method 200 for manufacturing a stamp 10 and a system 300 configured to execute in operation a method for manufacturing a stamp as disclosed herein.

[0073] As illustrated, the method can include providing 201 a stamp base having a surface provided with a plurality of laterally separated upright stamp protrusions, the stamp base and protrusions being optically transparent, and coating 204 the end faces at the tips of the stamp protrusions with an opaque cap 13, the coating including supplying on an applicator 303 a layer 54 of a curable ink composition 55 having an opaque quality when cured, transferring at least a portion of the ink to the tips 205, and then curing the ink 206.

[0074] A stamp base having a surface provided with a plurality of laterally separated upright stamp protrusions can be formed by conventional methods known in the art, such as from PDMS or rubber molding.

[0075] This process can be preferably carried out by the system 300 shown in FIG. 7. The system includes a source (container 301), an applicator roller 303, and a receiver roller 304.

[0076] During operation, as shown for example, the receiver roller 304 carries a stamp base having a surface provided with a plurality of upright stamp protrusions separated laterally along its outer surface. The amount of ink having an opaque quality is transferred from the container 301 to the tip of the stamp via the application roller 303 by contacting the protrusions with the carrier of the ink layer 54 on the application roller. After being transferred, the ink at the tip is cured (e.g., by light from the light source 82 as shown, or by heat) to form the opaque cap 13. When all the tips are coated, the stamp can be removed. Alternatively, the stamp can be exposed to a further processing cycle to increase the thickness of the cap. The tip can be pushed into the layer 54 over a desired distance in order to coat a part of the sidewall of the stamp protrusion (see FIG. 2) over a desired length.

[0077] As shown, the receiver roller is arranged in a reverse rotation relationship with respect to the applicator roller. The application roller and the receiver roller can be positioned relative to each other such that the tip of the stamp protrusion contacts or penetrates into the film of the curable ink composition.

[0078] In a preferred embodiment, as shown for example, the system further includes a substantially rigid raised portion 58 positionable at a controllable separation distance from the outer surface of the applicator roller to form a slit for controlling 203 the thickness of the film of the curable ink composition.

[0079] As described in relation to methods or systems for manufacturing stamps, methods and systems for manufacturing stamps may include means / steps for removing uncured residue from one or more rollers and / or stamps, and / or means / steps for heating uncured ink before or during the patterning of the stamps.

[0080] In another or further preferred embodiment, the system may include one or more transfer rollers 302 configured to transfer ink from a container to an application roller, for example, as shown in the illustration. The inventors have found that a system having at least one transfer roller for transferring ink from a container to an application roller is preferably particularly suitable for preventing coating of the surface of the stamp base between the stamp projections 11, in combination with means for controlling the thickness (t) of the film on the transfer roller (e.g., the raised portion 58).

[0081] In another embodiment, a further method for manufacturing a substrate including a carrier substrate having a relief structure is presented. In contrast to the method described above with reference to Figures 1A to 1E, this method is based on so-called reverse imprinting. Unlike forward imprinting, in reverse imprinting, the recesses between the stamp, particularly the stamp protrusions, are pre-filled with a fluid photocurable composition after the composition has been transferred to the substrate. Pre-filling the material recesses and then selectively transferring the material to the substrate, rather than pressing the stamp into a pre-deposited layer on the substrate, is less limited by squeezing out excess composition between the substrate and the tip of the stamp. Advantageously, the pre-filling of the stamp can be substantially limited to the recesses, and substantially no fluid photocurable material remains at the tip of the stamp.

[0082] Therefore, a reverse imprint method for manufacturing patterned substrates is provided.

[0083] In some embodiments, as illustrated, for example, in FIG. 8A, the method comprises: a) providing a stamp 10 having a plurality of laterally separated upright stamp protrusions 11 extending from the surface of a stamp base (12), step 401; b) filling a recess 17 between the laterally separated upright stamp protrusions with a flowable photocurable composition (50), step 402; c) reverse imprinting the photocurable layer, step 403, which comprises pushing the stamp 10 into the carrier substrate P to contact the tips of the stamp protrusions 11 with the carrier substrate 21, thereby contacting the flowable photocurable composition with the carrier substrate; d) selectively curing the photocurable composition while reverse imprinting (i.e., while the tips of the stamp protrusions 11 are in contact with the carrier substrate), step 404, which comprises irradiating light through the stamp onto the photocurable composition, thereby transferring the flowable photocurable composition from the recesses and forming a relief structure; e) removing the stamp from the carrier substrate and the formed relief structure, step 405; and optionally f) removing any uncured residues of the photocurable layer, if present, from the stamp and / or the carrier substrate, step (406), wherein the stamp (see FIG. 8B) is provided with an opaque cap 13 extending along the end face of the tip of the stamp protrusion 11, the cap comprising a polymer or polymer composite material, preferably an elastomer or elastomer composite material.

[0084] Advantageously, the stamp and the flowable photocurable composition, and further other features as described above and as shown, for example, in FIGS. 2 and 3, can be substantially the same as those described for the forward imprinting process as described with respect to FIG. 1.

[0085] The step of filling the recesses can be provided by means known in the art including, but not limited to, slot die coating and doctor blading. In a preferred variation, the recesses can be filled by transferring a photocurable composition from a pre-deposited layer. For example, it is done by pressing a stamp (such as one prepared on a carrier roller) onto a carrier substrate carrying a pre-deposited layer of a flowable photocurable material 50. To minimize the coating at the tip of the stamp protrusions, excess material can be removed, for example wiped off, using, for example, the raised portion 62 shown in FIG. 5C. Alternatively, or in addition, the excess can be limited by setting the thickness of the pre-deposited layer to correspond to the available volume within the stamp recesses. FIG. 8C illustrates the stamp after step 402 before 403, which is filling its recesses with uncured photocurable composition 50. As illustrated in FIG. 8D, in step 403, the pre-filled stamp is brought into contact with, i.e., pressed against, the carrier substrate 21. While in contact, curing occurs by light irradiation (L) through the stamp. After curing and removing the stamp, a relief structure 22 is formed on the substrate. For the patterned substrate described with respect to FIG. 1E, no residue can remain on the surface 21s of the substrate between adjacent relief elements (23).

[0086] In some embodiments related to reverse imprinting, the curable fluid composition 50 has a viscosity that increases towards the carrier substrate to facilitate transfer of the curable composition from the stamp to the carrier substrate. Similar to that described above for forward imprinting and shown in FIG. 4, the viscosity gradient is such that the viscosity increases towards the carrier substrate (i.e., opposite to the viscosity gradient that can be used for forward imprinting), and the curable composition 50 consists of a multi-layer stack formed from lower layers (50-1, 50-2, 50-n), for example, two, three, or more layers. Alternatively, or in addition, such a viscosity gradient can be achieved by applying a temperature gradient to the curable composition in which the temperature decreases towards the carrier substrate, for example, by heating the curable composition from the direction of the stamp before and / or during imprinting.

[0087] Before and / or during step 404, pulsed laser radiation can be applied to the curable composition from the direction of the stamp. Advantageously, applying pulsed laser irradiation, sometimes also referred to as laser-induced forward transfer (LIFT), smoothens the transfer of the curable composition from the stamp recesses onto the carrier substrate by vaporization of a small amount of the curable composition, thereby pushing and accelerating the non-vaporized portion of the curable composition towards the carrier substrate. The exact conditions, such as laser wavelength and pulse duration, can depend on factors such as the nature of the curable composition and the dimensions of the recesses, and can be selected by a person skilled in the art based on, for example, the information provided by Serra et al., Advanced Materials Technologies 2018, 4, 1800099.

[0088] Advantageously, in addition to smoothening the transfer of the curable composition, pulsed laser irradiation can also cause the curable composition to cure to some extent, thereby smoothing the shortening of the curing time.

[0089] For the sake of clarity and to provide a concise description, features are described herein as part of the same or separate embodiments, but it will be understood that the scope of the invention may include embodiments having combinations of all or some of the features described.

[0090] For example, in some variations, a patterned substrate is provided that includes a second relief structure formed along the surface of the carrier substrate opposite the first relief structure. FIG. 9 illustrates an exemplary substrate 21 having two different surface reliefs 22, 22-2 formed on either surface. The double-sided patterned substrate 20 shown in FIG. 9 may be particularly beneficial in double-sided electrode applications, such as in a battery cell stack.

[0091] When interpreting the appended claims, the word "comprising" does not exclude the presence of elements or acts other than those listed in a given claim, the words "a" or "an" before an element do not exclude the presence of a plurality of such elements, reference signs within the claims do not limit the scope, several "means" may be represented by the same or different items or implemented structures or functions, and any of these disclosed devices or parts thereof, unless otherwise stated, can be combined together or separated into further parts. If one claim refers to another claim, this may indicate a synergistic advantage achieved by the combination of their respective features. However, the mere fact that certain measures are recited in different claims does not indicate that the combination of these measures cannot also be used advantageously. Accordingly, embodiments of the invention may well include all usable combinations of the claims, and each claim, in principle, refers to any preceding claim unless clearly excluded from the context.

Description of Reference Signs

[0092] L light 10 stamp 11 Stamp protrusion 12 Stamp base 13 Opaque Cap 15 Side wall 16. Metal coating or ceramic coating 17 Recess 20 circuit boards 21s side 21 Carrier substrate 21a Flexible polymer foil 22 Relief Structure 23 Protrusions 29 Metal top coat 50 Fluid photocurable layer 58 Ridge 60 Applicators 62 Ridge 80 Applicators 81 Hard ridge 82 Curing System 100 ways 200 ways 300 Systems 301 Container 302 Transfer Roller 303 Applicator Roller 304 Receiver Roller 400 ways 500 Systems 501 Supply Roller 502 Recovery Roller 504 Patterned Roller 510 Patterning Station 600 System 601 Supply Roller 602 Recovery Roller 610 Patterning Station

Claims

1. A method (100) for manufacturing a substrate (20) including a carrier substrate (21) having a relief structure (22), i) Providing a stamp (10) having a plurality of laterally separated upright stamp projections (11) extending from a stamp base (12), ii) A step (102) of depositing a fluid photocurable layer (50) on the carrier substrate, iii) Step (103) of imprinting the photocurable layer, wherein step (103) is to press the stamp into the layer (P) and bring the tip of the stamp projection into contact with the carrier substrate, thereby displacing the layer at a position between the substrate and the tip of the stamp projection, iv) A step (104) of curing the photocurable layer while imprinting, wherein the step (104) includes irradiating the photocurable layer with light (L) to form the relief structure, v) Step (105) of removing the stamp from the carrier substrate and the formed relief structure, vi) step (106) remove any uncured residue of the photocurable layer from the stamp and / or the carrier substrate, if present. Includes, The method wherein the stamp projection comprises an opaque cap (13) extending along the end surface (14) of the stamp projection, and the cap comprises a polymer or composite material, preferably an elastomer or elastomer composite material.

2. A method (400) for manufacturing a substrate (20) including a carrier substrate (21) having a relief structure (22), a) Providing a stamp (10) having a plurality of laterally separated upright stamp projections (11) extending from the surface of the stamp base (12), b) A step (402) of filling the recess (17) between the horizontally separated upright stamp protrusions with a fluid photocurable composition (50), c) Step (403) of imprinting a photocurable layer in the reverse direction, wherein step (403) includes pressing the stamp (10) onto the carrier substrate (P), thereby bringing the fluid photocurable composition into contact with the carrier substrate, d) A step (404) of selectively curing the photocurable composition while imprinting in the reverse direction, wherein the step (404) includes irradiating the photocurable composition with light through the stamp, thereby transferring the fluid photocurable composition from the recess and forming the relief structure, e) Step (405) of removing the stamp from the carrier substrate and the formed relief structure, f) step (406) removing any uncured residue of the photocurable layer from the stamp and / or the carrier substrate, if present. Includes, The stamp is provided with an opaque cap (13) extending along the terminal surface of the tip of the stamp projection (11), and the cap comprises a polymer or polymer composite material, preferably an elastomer or elastomer composite material, method (400).

3. The method according to claim 1 or 2, wherein the cap partially extends along the side wall (15) of the stamp projection (11).

4. The method according to any one of claims 1 to 3, wherein the cap has higher rigidity than the stamp projection.

5. The method according to any one of claims 1 to 4, wherein the deposited photocurable layer (50) or the fluid photocurable composition in the recess between the stamp protrusions is heated before and during the imprint.

6. The method according to claim 5, wherein the step of heating the deposited photocurable layer (50) is performed from the direction of the carrier substrate, so that the deposited photocurable layer (50) has a temperature that rises toward the carrier substrate.

7. The method according to any one of claims 1, 3 to 6, wherein the fluid photocurable layer (50) has a viscosity that decreases toward the carrier substrate.

8. The method according to claim 5, wherein the step of heating the fluid photocurable composition in the recess between the stamp protrusions is performed from the direction of the stamp, so that the fluid photocurable composition has a temperature that decreases toward the carrier substrate.

9. The method according to any one of claims 2 to 5 and 8, wherein the fluid photocurable composition (50) in the recess between the stamp protrusions has a viscosity that increases toward the carrier substrate.

10. The method according to any one of claims 1 to 9, wherein the steps under iii), iv), and optionally v), or under c), d), and optionally e), are performed at a pressure lower than atmospheric pressure.

11. The method according to any one of claims 1 to 10, wherein the photocurable layer or the photocurable composition comprises 1 to 10% by weight of an organic solvent.

12. The carrier substrate (21) is an elongated web (21a), preferably a flexible metal foil or a flexible metal-coated foil. - A step of depositing the fluid photocurable layer, or a step of filling the recess with a photocurable composition, - Step of imprinting the photocurable layer, or step of imprinting in the reverse direction, - A step of curing the photocurable layer or the photocurable composition, - The step of removing the stamp, - A step to remove any uncured residue from the photocurable layer, if present. The method according to any one of claims 1 to 11, which is embodied along a roll-to-roll processing line.

13. The method according to claim 12, wherein the stamp is provided as a belt suspended on the outside of a roller or between two or more rollers.

14. The method according to any one of claims 1 to 13, wherein the relief structure is formed on the opposing surfaces of the carrier substrate.

15. The method according to any one of claims 1 to 14, further comprising the step of coating the substrate with a conductive adhesion-promoting layer, wherein the adhesion-promoting layer preferably includes a metal layer or metal oxide layer configured to act as an etch stop during the step (106, 406) to be removed.

16. The method according to any one of claims 2 to 5 and 8 to 15, further comprising the step of removing the fluid photocurable composition from the tip of the stamp projection before the step of reverse imprinting.

17. The method according to any one of claims 2 to 5 and 8 to 16, wherein pulsed laser radiation is applied to the photocurable composition from the direction of the stamp before and / or during the curing step d).

18. The stamp (10) for use in the method according to any one of claims 1 to 17, comprising a stamp base (12) having a surface on which a plurality of laterally separated upright stamp projections (11) are provided, wherein the stamp base and the projections are optically transparent, and the stamp is provided with an opaque cap (13) extending along the end surface of the tip of the stamp projections, wherein the cap is formed of a polymer or composite material, preferably an elastomer or elastomer composite material.

19. The stamp according to claim 18, wherein the cap partially extends along the side wall (15) of the stamp projection.

20. The stamp according to claim 18 or 19, wherein the cap has higher rigidity and optionally higher hardness than the stamp projection.

21. The stamp according to any one of claims 18 to 20, further comprising a metal coating or ceramic coating (16) extending on the cap or between the cap and the stamp projection.

22. The stamp according to any one of claims 18 to 21, wherein the outer surface of the cap has relatively higher hydrophobicity than the outer surface of the upright stamp projection.

23. A method (200) for manufacturing a stamp according to any one of claims 19 to 22, Step (201) provides a stamp base (12) having a surface on which a plurality of horizontally separated upright stamp projections (11) are provided, wherein the stamp base and the projections are optically transparent, The step (204) involves coating the end surface at the tip of the stamp projection with an opaque cap (13), The coating step is A layer (54) of a curable ink composition (55) having an opaque quality when cured is supplied onto the applicator, the ink is transferred to the tip, and then (206) A step of curing the ink. Step (204) and Method (200), including.

24. The method according to claim 23, further comprising the step (203) of controlling the thickness of the layer (54) in the applicator.

25. The method according to claim 23 or 24, further comprising the step of depositing a ceramic or metal coating.

26. A system (300) configured to perform the method (200) according to any one of claims 23 to 25 for manufacturing a stamp (10) according to any one of claims 18 to 22, A source (301) for holding a certain amount of a curable ink composition (55) which has an opaque quality when cured, Applicator roller (303), A receiver roller (304) is arranged in a reverse rotation relationship with respect to the applicator roller, The applicator roller is configured to receive a film of the curable ink composition (55) from the supply source along the outer surface of the applicator roller when in use. The receiver roller is configured to transport a stamp (10), which includes a stamp base having a surface on which a plurality of horizontally separated upright stamp protrusions are provided, along its outer surface when in use. The application roller and the receiver roller are positioned relative to each other so that the tip of the stamp projection contacts the film of the curable ink composition, and the receiver roller (304) A system (300) equipped with the following.

27. The system according to claim 26, further comprising a substantially rigid ridge (58) positioned at a controllable separation distance from the outer surface of the applicator roller that forms a slit for controlling the thickness of the film of the curable ink composition.

28. A system (500, 600) configured to carry out a method (100, 400) for manufacturing a substrate (20) including a carrier substrate (21) having a relief structure (22) as described in any one of claims 1 to 17, Applicators (60, 80) and A stamp (10) according to any one of claims 18 to 22, Pressure system and, A curing system (82) including a light source and Equipped with, The applicator is configured to deposit a fluid photocurable layer (50) onto the carrier substrate (102), or to fill the recesses (17) between laterally separated upright stamp protrusions with a fluid photocurable composition (50) (402). The pressure system is configured to bring the tip of the stamp projection into contact with the carrier substrate. The curing system is configured to irradiate (L) the photocurable layer or the photocurable composition (50) with light during the imprint (103, 403), and the system (500, 600).

29. A substrate (20) preferably obtained by the method according to any one of claims 1 to 17, using a stamp (10) according to any one of claims 18 to 22, comprising a carrier substrate (21) having a relief structure (22) formed thereon, wherein the relief structure comprises a plurality of isolated, laterally separated relief elements (23) formed from a cured polymer composition, the carrier substrate (21) comprises a foil (21a) having a metal foil or metal coating (21b), and the surfaces of the carrier substrate between the laterally separated protrusions are free from coatings or residues that would prevent direct electronically conductive contact with the substrate (20).

30. The substrate according to claim 29, further comprising a metal topcoat (29) disposed on the surface of the carrier substrate between laterally separated protrusions and extending in a shape conformable manner along the laterally separated relief elements.

31. The substrate according to claim 29 or 30, comprising a second relief structure (22-2) formed along the surface of the carrier substrate facing the first relief structure.

32. A battery electrode comprising a substrate according to any one of claims 29 to 31.

33. An energy storage device comprising one or more electrodes as described in claim 32 and an electrolyte.

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