NL2011363C2

NL2011363C2 - A method of and a system for treating a thin film of a coating liquid.

Info

Publication number: NL2011363C2
Application number: NL2011363A
Authority: NL
Inventors: Christianus Wilhelmus Johannes Berendsen; Hubertus Mattheus Joseph Maria Wedershoven; Josephus Catharina Henricus Zeegers; Anton Alexander Darhuber
Original assignee: Univ Eindhoven Tech
Priority date: 2013-08-30
Filing date: 2013-08-30
Publication date: 2015-03-03

Description

A METHOD OF AND A SYSTEM FOR TREATING A THIN FILM OF A COATING LIQUID

FIELD OF THE INVENTION

The invention relates to methods and systems for redistributing a film of coating liquid in a controlled fashion or for depositing a patterned coating from a film of coating liquid on a surface which is partially-wettable to the coating liquid.

BACKGROUND ART

In technological applications such as for example organic electronics, organic photovoltaics or the manufacturing of organic light emitting diodes (OLEDs), the creation of patterned coatings from a coating liquid is desirable. A coating liquid typically is a solution, dispersion or suspension consisting of one or more volatile solvents, one or more functional materials such as conductors or semiconductors, pigments, light emitting dyes or polymers, resin, or nanoparticles and possibly additives such as surfactants and rheology modifiers.

Traditional industrial roll-to-roll coating techniques are able to deposit thin and uniform films of coating liquid at high production throughput. Examples of such techniques are (continuous) dip coating, rod coating, air-knife coating, gravure coating, curtain coating, extrusion coating and slot-die coating. After drying and evaporation of the solvent from the coating liquid, the remaining coating typically consists of the functional material.

Patterned coatings can be achieved by photolithography processes or masking techniques. However, these techniques are not compatible with roll-to-roll processing. Other printing techniques such as flexography, inkjet-, gravure- and offset printing are roll-to-roll compatible, but cannot be used on substrates that are partially-wettable with respect to the coating liquid, as this would induce undesired redistribution and pattern distortions.

In slot-die coating, shims can be inserted in the slot die to obtain a striped coating along the coating direction, while intermittent operation of the coating apparatus can produce stripes perpendicular to the coating direction.

The wettability of a substrate is measured by the receding contact angle “Θ” of a liquid on a solid substrate. Material systems with a receding contact angle of (close to) zero degrees are termed “fully-wettable”, whereas a receding contact angle with a value larger than zero indicates a “partially-wettable” surface. Whether the material system is fully-wettable or partially-wettable depends on the characteristics of the liquid and of the surface on which the liquid is provided.

Typically the substrate, for example a metal or polymer foil, is pretreated to be fully-wettable to the coating liquid to ensure full coverage and coating uniformity. Pretreatment can be done by for example corona treatment, plasma processing or chemical activation.

Published patent application W02005/014184 A1 discloses a method for producing patterned coatings. The disclosed method comprises pre-patterning the wettability of the substrate. When chemically pre-patterned substrates, consisting of wettable and partially-wettable or non-wettable areas, are coated in, for example, a slot-die coater, the liquid retracts from the edges of the substrate and collects on the fully-wettable areas. To ensure uniform distribution of liquid over the hydrophilic areas, W02005/014184A1 discloses destabilization or rupture of the film of coating liquid. A method for destabilization demonstrated in Example 4, is the use of gas jets. Unfortunately, gas jets impinging onto liquid films on partially-wettable areas typically cause a pattern of residual droplets on the partially-wettable areas, leaving coating solution and - after evaporation of the solvent - solid residue on unwanted locations.

Destabilization or rupture of a film of coating liquid on a partially-wettable area results in a locally dry surface area. Redistribution of coating liquids comprises the growth of dry regions and the accumulation of coating liquid. Spontaneous redistribution of coating liquid on a flat and homogeneous partially-wettable surface typically happens uniformly in all directions.

Published patent application WO2012/150263 discloses a method for controlling the deposition of a solute or dispersed particles in a liquid medium. The disclosed method comprises the steps of: a) providing a substrate provided with a layer of a liquid medium comprising the solute or the dispersed particles, b) modulating the surface temperature of the layer according to a heat pattern to induce movement of the solute or the dispersed particles and c) at least partially evaporating the liquid medium to deposit at least part of the solute or the dispersed particles during and/or after step b). The disclosure of the patent application relates to fully-wettable substrates because, as disclosed, it takes at least 1 minute up to 120 minutes to perform the method. The layer of the liquid can only be present on the surface of the substrate for such periods of time when the surface is a fully-wettable surface. In the patent application WO2012/150263 heat is used to locally change the thickness of the liquid such that, when the liquid is fully evaporated a coating layer is present of which the thickness varies along the surface.

Drawback of the WO2012/150263 is that it cannot be applied to a partially-wettable surface because it takes a relatively long time to perform the above discussed method. When the coating liquid and the surface are not part of a fully-wettable material system, which means that, when the coating liquid is applied in a thin film to the surface and does recede within a relatively short time after being applied to the surface, the method and system of the cited patent application cannot be used. In such case, additional surface treatment steps must be applied to obtain a fully-wettable surface.

SUMMARY OF THE INVENTION

One of the objects of the invention is to provide a method and system for treating a thin film of a coating liquid which does not require a fully wettable surface. A first aspect of the disclosure provides a method of treating a thin film of a coating liquid that is applied to a substrate for redistributing the coating liquid along a substrate in a controlled fashion or for depositing a patterned coating on the substrate. A second aspect of the disclosure provides a system for treating a thin film of a coating liquid being applied to a substrate for redistributing the coating liquid along a substrate or for depositing a patterned coating on the substrate. Embodiments are defined in the dependent claims.

The method of treating a thin film of a coating liquid that is applied to a substrate. The method is for redistributing the coating liquid along a substrate in a controlled fashion and for depositing a patterned coating on the substrate. The method comprises the stages of i) obtaining the substrate and the coating liquid, the substrate comprises partially-wettable areas that are partially-wettable with respect to the coating liquid, if the coating liquid is provided on at least one partially-wettable area, a static receding contact angle of the coating liquid provided on the at least one partially-wettable area is in between 5 and 150 degrees, the coating liquid comprises a deposition material and a liquid, the deposition material is a material that has at least one of the following characteristics: a) a portion of the deposition material directly deposits on the substrate on the specific position when the liquid of the coating liquid at least partly evaporates, b) before or after being deposited, the deposition material chemically reacts under the influence of heat or light, and, c) before or after being deposited, the deposition material changes under the influence of heat or light towards a solid material, ii) applying a thin film of the coating liquid to the substrate, the applying of the thin film being performed by a coating apparatus being arranged for at least temporarily providing the thin film of the coating liquid on at least one of the partially-wettable area, and the method comprises at least one of the subsequent stages: I) deforming the thin film by locally heating the thin film, the substrate or an object supporting the substrate in case of a thin foil substrate, wherein a specific position within at least one of the partially-wettable areas is heated, the local heating is performed before the thin film recedes from the one of the partially-wettable areas, II) rupturing the thin film by locally heating the thin film, the substrate or an object supporting the substrate in case of a thin foil substrate, wherein a specific position within at least one of the partially-wettable areas is heated, the local heating is performed before the thin film recedes from the one of the partially-wettable areas, III) locally accelerating a receding contact line by locally heating the thin film, the substrate or an object supporting the substrate in case of a thin foil substrate, wherein a specific position within at least one of the partially-wettable areas is heated, the local heating is performed before the thin film recedes from the one of the partially-wettable areas, IV) depositing the deposition material at the specific position by locally heating the thin film, the substrate or an object supporting the substrate in case of a thin foil substrate, wherein a specific position within at least one of the partially-wettable areas is heated, the local heating is performed before the thin film recedes from the one of the partially-wettable areas.

The above discussed method can advantageously be used to create a pattern, also on partially-wettable areas of the substrate. However, the method must be performed in such a way that the heat is locally applied to the thin film of the coating liquid before the coating liquid recedes. Coating liquids which are applied to a partially-wettable automatically recede after a short period of time. The skilled persons in the art are biased against patterning thin films of a coating liquid on partially-wettable surfaces by using heat because of the automatic receding of the thin film. In the above method, the applying of heat must be done shortly after, or, in an embodiment even, immediately after creating the thin film such that the application of the heat is done before the thin film recedes. Thus, the above presented method comprises a speed component which prescribes that the application of the heat must be done relatively fast. This implies that within relatively short periods of time the heat must be applied. When creating a pattern on a partially-wettable area an additional advantage was observed by the inventors. Compared to the known method in which heat was used to create in a thin film of a coating liquid different thicknesses to obtain a patterned coating, the inventors observed that from the location where the material was deposited the coating liquid receded without leaving any droplets of the coating liquid, which results in a very high contrast between a location where the deposition took place and a location where no material was deposited. Thus, the inventors have found that the pattern quality increases when a pattern is created on a partially-wettable area according to the method of the first aspect.

It is also the insight of the inventors that the above method can also be used to redistribute the coating liquid in a controlled fashion by locally forcing the thin film to rupture and/or to accelerate the receding contact line under the influence of heat. Because the thin film ruptures in one of the partially-wettable areas, the film will recede from the location where the film ruptures. Thus, the above method may be used to clearly define the location where the receding starts. Moreover, the speed of the receding contact line, i.e. the dewetting speed, is increased under the influence of heat and the liquid redistribution can thereby be better controlled. Compared to a known method of W02005/014184 A1 which also tries to destabilize or rupture the thin film coating liquid on a partially-wettable surface, the inventors have found that the above method provide a huge benefit: the rupturing and the receding of the coating liquid is without leaving any droplets. A possible cause of this effect might be that the expansion rate of the first dry-spot that formed exceeded the substrate speed as a consequence of the increased local temperature and thus the decreased viscosity of the coating liquid.

It is to be noted that the partially-wettability of the partially-wettable areas is defined with respect to a specific coating liquid. The combination of the specific coating liquid and the characteristics of the surface of the partially-wettable areas defines whether one speaks about a partially-wettable area. In general partially-wettable is defined by a static receding contact angle of the coating liquid applied to a specific surface and this static receding contact angle is in a specific range when the specific surface is partially-wettable.

Theoretically, the static contact angle of a sessile droplet or a stationary contact line of liquid on a solid substrate is determined by the surface tension of the liquid and the surface energy of the solid through the Young equation.

In practice, due to micro- or nanoscale surface roughness or topography, chemical heterogeneities and/or adsorption effects, the static contact angle assumes a value between a minimum value (the static receding contact angle) and a maximum value (the static advancing contact angle). The difference between static advancing contact angle and static receding contact angle is called contact angle hysteresis.

The static receding contact angle can be measured by slowly decreasing the volume of a droplet of liquid on the solid (the dynamic sessile drop method). When the solid/liquid interfacial-area starts decreasing, the static receding contact angle is reached.

Likewise, the static advancing contact angle is the angle of the droplet when the solid/liquid interfacial-area grows slowly.

Material systems with a static receding contact angle of (close to) zero degrees are termed “fully wettable”, whereas a static receding contact angle with a value larger than zero indicates a “partially-wettable” surface.

For the successful implementation of the above method, the static receding contact angle of the liquid on the partially-wettable area should be higher than zero, such as between 5 and 150 degrees, or such as between 20 and 50 degrees. The angle is the angle defined within the liquid between a line following a surface of the liquid at the location where the liquid touches the partially-wettable area and a line following the partially-wettable area. A too low static receding contact angle may lead to contact line pinning and residual droplets at locations of variation in the surface properties. Too high static receding contact angle leads to too high dewetting speeds making it difficult to deposit a liquid film on the partially-wettable surface or making it difficult to control the film rupture or the redistribution of the thin film.

In contrast to the static receding contact angle for slow movement of the contact line, the dynamic receding contact angle is dependent on contact line velocity. With increasing relative speed between the liquid meniscus and the solid substrate, the dynamic receding contact angle goes from the value of the static receding contact angle towards zero. This effect allows a liquid to be coated or entrained onto a partially wetting solid. The dynamic receding contact angle not only depends on the surface properties and surface tension of the liquid, but also on the viscosity of the liquid.

For depositing a material on the substrate, the coating liquid comprises the deposition material having the above described characteristics. The deposition material is the basis for, or, in other words, the starting material, of the material that is being deposited by the method. The chemical reaction may be one of gelation, partial sublimation, polymerization, or crystallization.

Optionally, the method further comprises the stage of relatively moving the substrate with respect to the specific position. In other words, the specific position moves to another location on the substrate. Thus, by the relative movement of the substrate with respect to the specific position, patterns may be written to the substrate, or specific redistribution pattern may be created. The through-put of the method can be increased by using a multitude of such specific positions simultaneously.

Optionally, in the stage of relatively moving the substrate with respect to the specific position, the speed of the relative movement is larger than an ambient- temperature dewetting speed of the coating liquid applied on the partially-wettable areas.

The ambient-temperature dewetting speed is the speed at which a contact line of a film of the coating liquid on the partially-wettable material would recede without being heated.

In an embodiment, when destabilization or rupture of the liquid film occurs or a pre-existing contact line is encountered, and the speed of relative movement is larger than an ambient-temperature dewetting speed, the redistribution of the liquid and the shape of the dry area can be controlled.

In another embodiment, in the absence of a contact line, a pattern may be written or deposited onto the partially-wettable substrate.

Optionally, in the stage of relatively moving the substrate with respect to the specific position, the speed of the relative movement is larger than an elevated-temperature dewetting speed of the coating liquid applied on one of the partially-wettable areas.

The elevated-temperature dewetting speed is the typical speed at which a contact line of a film of the coating liquid on the partially-wettable material would recede when heated to the temperature of the specific position, i.e. increased with respect to the ambient-temperature dewetting speed due to the local heating.

In an embodiment, when the speed of relative movement is larger than the elevated-temperature dewetting speed, a pattern may be written / deposited to the partially-wettable substrate. Along the trajectory of the specific location, a material may be deposited or a portion of the coating liquid may remain. If destabilization or rupture accidentally occurs, the high speed of the relative movement ensures that deposition continues. Optionally, when the substrate moves relatively to the specific position, a movement speed of the stage of relatively moving the substrate with respect to the specific position and an amount of heat which is applied to the thin film of coating liquid or to the substrate in the stage of locally heating the thin film of coating liquid or the substrate are selected to such that the liquid of the coating liquid which remains at the specific position after receiving the heat evaporates. This optional embodiment directly deposits a depositing material being present in the coating liquid.

Optionally, a movement speed of the stage of relatively moving the substrate with respect to the specific position and an amount of heat which is applied to the thin film of coating liquid or to the substrate in the stage of locally heating the thin film of coating liquid or the substrate are further selected such that the liquid of the coating liquid which remains at the specific position after receiving the heat is left behind. In this example, some coating liquid remains at the specific position and at the area around the specific position the coating liquid recedes. The remaining coating liquid forms a basis for forming a patterned coating.

Optionally, in the stage of relatively moving the substrate with respect to the specific position, the substrate is moved in a roll-to-roll configuration, wherein the substrate is a foil. In the roll-to-roll configuration the foil is provided on a first rotating roll which provides the foil to a coating apparatus applying a thin film of coating liquid and after the locally heating of the foil or the thin film of coating liquid, and possible drying, conversion or post-treatment steps the foil is rolled up on a second rotating roll. In between the first rotating roll and the second rotating roll a specific coating technology is used to create at least temporarily the thin film coating. Examples of such techniques are (continuous) dip coating, curtain coating, extrusion coating and slot-die coating. The coating apparatus may also comprise additional means for influencing the thickness of the film of coating liquid. Examples of such means are a knife, a brush, a doctor blade, an air-knife, a rod. The roll-to-roll system may comprise more than two rotating rolls and additional processing equipment such as for drying, conversion or deposition. For example, a third roll comprises heating elements for locally heating the foil.

Optionally, the static receding contact angle of the coating liquid when being applied on one of the partially-wettable surface is in a range from 5 to 150 degrees. Above a definition of the static receding contact angle has been given. In another embodiment, the static receding contact angle is in a range from 15 to 80 degrees, or, in a further embodiment, the static receding contact angle is in a range from 20 to 50 degrees.

Optionally, the coating liquid comprises poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), which is often abbreviated with PEDOT:PSS.

According to a second aspect, a system for treating a thin film of a coating liquid being applied to a substrate is provided. The treating of the thin film is for redistributing the coating liquid along a substrate and for depositing a patterned coating on the substrate. The coating liquid and the substrate being part of a material system wherein substrate comprises partially-wettable areas that are partially-wettable with respect to the coating liquid, if the coating liquid is provided on at least one partially-wettable areas; a static receding contact angle of the coating liquid provided on the at least one partially-wettable area is in between 5 and 150 degrees; the coating liquid comprises a deposition material and a liquid, the deposition material is a material that has at least one of the following characteristics: i) a portion of the deposition material directly deposits on the substrate on the specific position when the liquid of the coating liquid at least partly evaporates, ii) before or after being deposited, the deposition material chemically reacts under the influence of heat or light, and, iii) before or after being deposited, the deposition material changes under the influence of heat or light towards a solid material. The coating apparatus is configured for applying a thin film of the coating liquid to the substrate and for at least temporarily providing the thin film of the coating liquid on the at least one of the partially-wettable areas. The heating subsystem is arranged for locally heating the at a specific position a thin film, the substrate or an object supporting the substrate (when the substrate is, for example,, a thin foil) at least within one of the partially-wettable areas for deforming the thin film, rupturing the thin film, locally accelerating a receding contact line, or depositing the deposition material at the specific position. The heating sub-system being configured for locally heating the specific position before the thin film recedes from the one of the partially-wettable areas. The system according to the second aspect has corresponding effects and benefits as the method of the invention and has corresponding embodiments.

Optionally, the heating sub-system comprises at least one of: i) a source of electromagnetic radiation for emitting electromagnetic radiation towards the specific position, wherein a wavelength of the electromagnetic radiation is selected to be absorbed by at least one of the thin film or the substrate or the support surface of the substrate (e.g. a roll in a roll-to-roll system), and ii) a resistive heating element arranged at a position close to or in contact with the substrate for locally heating the substrate. The heating sub-system may also comprise a plurality of sources of electromagnetic radiation and/or a plurality of resistive heating elements.

Optionally, when the heating sub-system comprises a source of electromagnetic radiation, the source of electromagnetic radiation is arranged for changing a light emission direction of the electromagnetic radiation in response to a control signal such that specific position moves with respect to the substrate. Thus, instead of moving the substrate to obtain a relative movement of the substrate with respect to the specific position, the specific position that receives the electromagnetic radiation may be changed, or the substrate may be moved and the specific position may be changed. Changing the light emission direction may be obtained by moving the source of electromagnetic radiation, or by controlling parameters of optical elements that are provided to shape, transmit or redirect a beam of the electromagnetic radiation. The optical elements may be lenses, optical fibers and/or mirrors. Other parameters of the source of electromagnetic radiation may be controlled as well, such as power, pulse duration, size of the area of the specific position (in other words: the size of the beam of electromagnetic radiation when hitting the substrate or the thin film).

Optionally, the system further comprises movement elements effecting a translation and/or a rotation of the substrate for relatively moving the substrate with respect to the specific position at which the heating sub-system provides the heat.

Optionally, the system further comprises a roll-to-roll foil coating system, wherein the substrate is formed by a foil, the roll-to-roll coating system comprises a first rotatable roll for providing the foil and a second rotatable roll for collecting the foil after the thin film has been provided to the foil and the foil has been locally heated by, respectively, the coating apparatus and the heating sub-system.

Optionally, the roll-to-roll system comprises a third rotatable roll being arranged at a location to contact the foil at a position where the thin film is still present at the foil and has not receded yet. The third roll could be made from or coated with a material that absorbs IR radiation in cases neither the substrate nor the liquid strongly absorbs the IR radiation.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter. In the drawings,

Fig. 1a schematically shows, in a top-view, a controlled redistribution of a film of coating liquid with a partially-wettable material system,

Fig. 1b schematically shows, in a cross-sectional view, the controlled redistribution of the film of coating liquid with the partially-wettable material system,

Fig. 2a schematically shows, in a top-view, a local deposition of a coating from a film of coating liquid with a partially-wettable material system,

Fig. 2b schematically shows, in a cross-sectional view, the local deposition of the coating from a film of coating liquid with the partially-wettable material system,

Fig. 3a schematically shows an embodiment of an apparatus for redistribution of a liquid coating with a partially-wettable material system or for the deposition of a coating with the partially-wettable material system,

Fig. 3b shows a photograph of a sample during treatment in the apparatus of Fig. 3a wherein the liquid coating is being redistributed in a controlled fashion,

Fig. 4A shows a photograph of another sample made with the apparatus of Fig. 3a wherein the coating is locally deposited from the coating liquid,

Fig. 4B shows a photograph of another sample made with the apparatus of Fig. 3a wherein the coating liquid is locally deposited,

Fig. 4C shows a photograph of another sample made with the apparatus of Fig. 3a wherein the coating is locally deposited,

Fig. 5a schematically shows, in a cross-sectional view, an embodiment of system for treating a thin film of a coating liquid being applied to a substrate for redistributing the coating liquid along a substrate or for depositing a patterned coating on the substrate,

Fig. 5b schematically shows, in a cross-sectional view, another embodiment of the system for treating a thin film of a coating liquid being applied to a substrate for redistributing the coating liquid along a substrate in a controlled fashion or for depositing a patterned coating on the substrate, and

Fig. 6 schematically shows a method of treating a thin film of a coating liquid applied to a substrate for redistributing the coating liquid along a substrate in a controlled fashion or for depositing a patterned coating on the substrate

It should be noted that items which have the same reference numbers in different Figures, have the same structural features and the same functions, or are the same elements. Where the function and/or structure of such an item has been explained, there is no necessity for repeated explanation thereof in the detailed description.

The Figures are purely diagrammatic and not drawn to scale. Particularly for clarity, some dimensions are exaggerated strongly.

DETAILED DESCRIPTION OF EMBODIMENTS

In a current technique for creating discontinuous, patterned coatings in a large-area coating machine, surface modifications of the substrate are required, such as rendering it locally or globally hydrophilic. In the case of chemically pre-patterned substrates and high coating speeds, liquid initially covers the entire substrate and this liquid needs to be redistributed in a subsequent step. This redistribution can be initiated by using a gas jet to disturb and rupture the liquid film, i.e. to generate a dry spot that grows and initiates dewetting. However, the use of a gas jet may lead to multiple dry-spots and the formation of undesirable residual droplets. A flexible system and method are presented that can control redistribution of a liquid, a solution, suspension or dispersion on a surface when at least part of the surface is partially-wettable without leaving residual droplets and which can be integrated with traditional coating techniques. This mode of operation is called “redistribution control mode”. In another mode of operation, the system can be used to deposit a patterned coating from a coating solution directly when a partially-wettable material system is used, which is material system in which a substrate is notoriously difficult to coat. This mode of operation is called “deposition mode”.

The inventors have found that by locally inducing a temperature rise in the thin film of coating liquid and /or its supporting substrate, the liquid redistribution can be initiated and controlled/steered/directed without leaving residual droplets. Moreover, in a different mode of operation, the solid content of the coating liquid and / or a nonreceding portion of the coating liquid can be directly deposited onto the partially-wettable substrate, which removes the need for surface pretreatment.

An embodiment of a source of heat is a source of electromagnetic radiation, such as a visible or an infrared (IR) laser, that generates heat upon absorption in or interaction with the thin liquid film and/or its supporting substrate and/or the object supporting the substrate in case of thin foil substrates. An alternative way to locally apply heat to the thin film of coating liquid, the substrate or both could be by locally touching the dry back-side of the substrate with a warm or hot object, such as an object heated by a resistive heater. The local heating could also be achieved by heating a part of a drum of the apparatus for applying a thin film of a coating liquid to the substrate

In coating applications this system/method can be used in two complementary modes of operation, described below: MODE 1: Redistribution control mode

In redistribution control mode, the non-uniform temperature distribution induces gradients in surface tension, causing the film to thin, and on partially wetting substrates to rupture and dewet. Moreover, locally higher temperatures decrease viscosity and possibly increase receding contact angles and therefore accelerate the contact line recession speed in the heated area allowing control over the redistribution of the liquid.

If a liquid film becomes sufficiently thin on a partially-wettable surface as a consequence of e.g. infrared heating, the liquid film will rupture. Alternatively, film rupture may be induced by other means, such as a gas-jet or mechanical contact with a hydrophobic object. Film rupture on a partially-wettable surface leads to the creation of a dry spot / dry area surrounded by a receding contact line, that moves/recedes with a so-called dewetting speed Vd, that is primarily determined by the viscosity of the liquid and the receding contact angle. Spontaneous redistribution on a homogeneous surface typically means that the dry area grows uniformly in all directions. When the liquid and/or the substrate is heated locally around the receding contact line, the dewetting speed will be increased locally. If there is relative motion between the heat source and the substrate, the dry spot will grow anisotropically and a dry line is created, which allows control of the redistribution of the coating liquid e.g. towards the hydrophilic domains on a chemically patterned surface or which divides and separates a large liquid coating on a chemically homogeneous, partially-wettable substrate. MODE 2: Deposition of a thin coating film from a solution or dispersion

For different values of the operating parameters (such as thickness of the film of coating liquid, substrate speed, heating power), i.e. in deposition mode, the non-uniform temperature distribution induces gradients in surface tension, causing the film to thin.

The inventors have observed deposition in two different appearances.

In one appearance (dry appearance), the temperature rise induces a deformation and rapid local evaporation of the solvent. The result is direct local deposition of a dry solid layer from the solution or dispersion on partially-wettable substrates, which are difficult to coat without surface modifications such as corona-discharge treatment otherwise.

In another appearance (wet appearance), the localized temperature increase of a coating liquid on a partially-wettable substrate results in the localized deposition of a non-receding amount of coating liquid. When drying, the solid content of the coating liquid is deposited on partially-wettable substrates, which are difficult to coat without surface modifications such as corona-discharge treatment otherwise. A combination of both appearances, solid deposition with small residual portions of coating liquid on top, has also been observed. Examples 2, 3 and 4 will illustrate both appearances.

In all appearances of the deposition mode, in the areas not heated by the electromagnetic radiation, the liquid will recede from the partially-wettable surface without leaving solid material.

In all appearances of the deposition mode, the deposition of solid content may further be accompanied by a temperature- or light-induced chemical reaction or phase transition such as gelation, (partial) sublimation, polymerization, adsorption or crystallization.

If in the following of this document the terms “partially-wettable area” or “partially-wettable surface” are used, one has to read that this specific area or surface is partially-wettable when a specific coating liquid is used, thus, in other words, the material used for the area / surface and the used coating liquid together forms a partially-wettable material system.

Figure 1 is a schematic drawing depicting an embodiment of the method for redistribution of coating liquid in an apparatus for controlled redistribution of a coating liquid or deposition of a patterned coating on a substrate. Figure 1A represents the top view, whereas Figure 1B represents the cross section along the dashed line A-A in Figure 1A. The area of a partially-wettable area of a substrate 14 is partially covered with a thin film 17 of coating liquid. The substrate is moving with respect to the source of electromagnetic radiation in the direction indicated by an arrow 15. A source of electromagnetic radiation 11 emits electromagnetic radiation 12, focused into a spot 13 on the substrate 14. Heat is induced in either the substrate 14, or the coating liquid 17 or both, causing the deformation of the coating liquid surface and the formation of a contact line 18, separating a dry line 16 and the thin film of coating liquid 17. The arrows along the contact line 18 indicate the direction of movement of the contact line due to the partially-wettable nature of the area of a partially-wettable area of a substrate 14.

Figure 2 is a schematic drawing depicting an embodiment of the method for deposition of a patterned coating in an apparatus for controlled redistribution of a coating liquid or deposition of a patterned coating on a substrate. Figure 2A represents the top view, whereas Figure 2B represents the cross section along the dashed line B-B in Figure 2A. The area of a partially-wettable area of a substrate 14 is partially covered with a thin film 17 of coating liquid. The substrate is moving with respect to the source of electromagnetic radiation in the direction indicated by an arrow 15. A source of electromagnetic radiation 11 emits electromagnetic radiation 12, focused into a spot 13 on the substrate 14. Heat is induced in either the substrate 14, or the coating liquid 17 or both, causing either the deformation of the coating liquid surface and evaporation of the solvent resulting in the deposition of a line of solid coating 20, or the localized deposition of a non-receding amount of coating liquid 21. After the deposition, the surrounding coating liquid 17 recedes from the area of a partially-wettable area of a substrate 14, leaving a dry surface without deposit left and right of the deposited line.

Figure 3A is a schematic drawing of the apparatus used for Examples 1,2, 3 and 4. Figure 3B is a microscope image obtained from Example 1 during treatment in the apparatus of Figure 3A. Figure 4A is a microscope image of a deposited line of solid poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS), a conductive material commonly used in organic (opto-)electronic devices) on a polycarbonate substrate, obtained from Example 2. Figure 4B is a microscope image of a deposited line of non-receding coating liquid comprising PEDOT:PSS on a polycarbonate substrate, obtained from Example 3. Figure 4C is a microscope image of a deposited intermitted line of non-receding coating liquid comprising PEDOT:PSS on a polycarbonate substrate, obtained from Example 4. A way to locally apply heat is by electromagnetic radiation, preferably with a wavelength absorbed most strongly in the liquid. The source of electromagnetic radiation could preferably be one or more lasers, preferably infrared lasers. The one or more lasers could be part of the apparatus or the light could be introduced by one or more optical fibers. The electromagnetic irradiation could be directed, focused or shaped by an array of one or more lenses, mirrors or other optical components. The laser could be operated in continuous mode, pulsed mode or duty cycled. The laser could be moved relative to the substrate physically or the beam could be steered by one or more mirrors. The operating parameters of the lasers or the optical system (which may comprise adjustable components such as deformable or tiltable mirrors, adjustable lenses and irises, phase plates, spatial light modulators, optical fibers etc.) could be controlled depending on the desired coating pattern.

The receding contact angle of the liquid on the partially-wettable area should be higher than zero, such as between 5 and 150 degrees, such as between 20 and 50 degrees.

The thin film of coating liquid, should be not be too much affected by gravity and therefore have a film thickness below 1 mm, below 100 micrometer, or below 20 micrometers.

In a preferred embodiment, the substrate is moving with respect to the heat source like in a commercial roll-to-roll coating line.

In the following, four examples are discussed. The examples are manufactured in a laboratory set-up/apparatus , which means that the microscope system is only present for recording images and is not necessary a part of the system to redistribute the coating liquid in a controlled fashion or form a patterned coating.

Example 1: redistribution control mode

This example is illustrated in the Figure 3A and 3B. Figure 3A is a schematic drawing of the system for controlled redistribution of a coating liquid or deposition of a patterned coating. A thin film of coating liquid 17 is applied to a partially-wettable substrate 14 by spin coating. The heating system consists of a source of electromagnetic radiation 11, generating electromagnetic radiation 12, focused onto the substrate 14 in a focal spot 13. The substrate with a thin film of coating liquid is rotated according to the arrow 15. A microscope system 30, properly shielded against electromagnetic radiation 12 enables imaging through the transparent substrate 14 of the liquid film during the process. The electromagnetic radiation follows a trajectory 31 over the substrate.

The substrate material used in this example is polycarbonate sheet (thickness 750 micrometers, Bayer Makrofol DE1-1). The coating liquid is an aqueous dispersion of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) nanoparticles (AGFA HILH-C5, solid content 0.63 weight percent), a relevant liquid for organic electronic devices. The static advancing contact angle was measured to be 60±5 degrees. The static receding contact angle was measured to be 30±5 degrees on the polycarbonate sheet, which means that it is a partially-wettable material for the coating liquid. A uniform thin film of a coating liquid with a thickness in the order of several micrometers is applied to the polycarbonate substrate. An infrared laser beam (wavelength 1470 nm) is focused into a spot with a diameter of approximately 0.25 mm on the liquid film. The substrate is moved with respect to the laser beam at a speed of 4.5mm/s. The laser power was 0.6W. The laser light is absorbed strongly by the coating liquid, causing a temperature increase. Due to the non-homogeneous temperature distribution, the thin film of coating liquid deforms and a dry-spot forms. The dewetting speed Vd is increased due to the higher temperature and the dry-spot expands, i.e. the coating liquid redistributes. Due to locally increase dewetting speed, a dry track is created along the trajectory, i,e the redistribution of coating liquid is controlled and directed along the trajectory. Figure 3B shows the propagation of this dry track, splitting the liquid film into two domains.

Example 2: deposition mode (dry appearance)

The apparatus of Figure 3A is used for this example. A thin film of an aqueous dispersion of PEDOT:PSS nanoparticles (solid content 0.63 weight percent) was spincoated on a partially-wettable polycarbonate substrate. An infrared laser beam of approximately 0.25 mm diameter is focused on the film, while the substrate is rotating, following a trajectory 31 along the substrate. The substrate is moved with respect to the laser beam with 30 mm/s and the laser power was set to 2.5W. A strong depression is created in the liquid film without causing film rupture. After the liquid has receded from the substrate, a narrow line of solid PEDOT:PSS is left on the substrate (see Figure 4A).

Example 3: deposition mode (wet appearance)

The apparatus of Figure 3A is used for this example. A thin film of an aqueous dispersion of PEDOT:PSS nanoparticles (solid content 0.63 weight percent) is spincoated on a partially-wettable polycarbonate substrate. An infrared laser beam of approximately 0.25 mm diameter is focused on the film, while the substrate is rotating, following a trajectory 31 along the substrate. The substrate is moved with respect to the laser beam with 60 mm/s and the laser power was set to 2.7W in continuous mode. A mild depression is created in the liquid film without causing film rupture. After the liquid has receded from the substrate, a narrow line of non-receding liquid coating solution is left on the substrate (see Figure 4B). After drying of the remaining coating solution, a line of solid coating remains on the substrate.

Example 4: intermittent deposition mode (wet appearance)

The apparatus of Figure 3A is used for this example. A thin film of an aqueous dispersion of PEDOT:PSS nanoparticles (solid content 0.63 weight percent) is spincoated on a partially-wettable polycarbonate substrate. An infrared laser beam of approximately 0.25 mm diameter is focused on the film, while the substrate is rotating, following a trajectory 31 along the substrate. The substrate is moved with respect to the laser beam with 60 mm/s and the laser peak power was set to 2.7W. The laser power was pulsed at 50Hz with a duty cycle of 75 percent (15ms ON, 5 ms OFF).

An intermittent, mild depression is created in the liquid film without causing film rupture. After the liquid has receded from the substrate, a dashed line of non-receding liquid coating solution is left on the substrate (see Figure 4C). After drying of the remaining coating solution, a dashed line of solid coating remains on the substrate.

Fig. 5a schematically shows, in a cross-sectional view, an embodiment of a system 500 for redistribution of a liquid coating with a partially-wettable material system or for the deposition of a coating with the partially-wettable material system. The system 500 is based on a roll-to-roll coating system in which a foil 504, which fulfills the role of a substrate, is provided with a thin film of the coating liquid and locally heated. A first rotating roll 502 provides the foil and, finally, after all the treatments, the foil is received by a second rotating roll 512. A third rotating roll 510 guides the foil 504 through a coating liquid 508. Portions at a first side 506 of the foil 504 are partially-wettable with respect to the used coating liquid 508. The foil 504 is moved with a specific speed through the coating liquid 508 and as such a thin film 520 of the coating liquid 508 is temporarily present on the foil 504. After some distance the thin film 520 recedes at least from the partially-wettable portions of the foil 504. Before the thin film 520 recedes from the foil 504, a heating sub-system locally heats the foil 504 or the thin film 520 to obtain a temperature gradient in the thin film. The resulting temperature gradient causes the thin film to deform and rupture or the temperature increase causes a localized deposition of a portion of coating liquid or of deposition material being present in the coating liquid 508 at the location where the foil 504 or the thin film 520 is heated. Fig. 5a presents two embodiment of the heating sub-system. A first embodiment is a source of electromagnetic radiation 518, for example, a laser, which emits electromagnetic radiation 516 to the thin film 520. A second embodiment is a heating element, for example, a resistive heating element 514 which is provided at a second side of the foil 504 that is opposite the first side of the foil 504 (where the thin film 520 is still present).

Fig. 5b schematically shows, in a cross-sectional view, another embodiment of the system 550 for treating a thin film 520 of a coating liquid being applied to a foil 504 for redistributing the coating liquid along a substrate or for depositing a patterned coating on the substrate. Several elements of Fig. 5b are similar to elements of Fig. 5a and have the same reference number. However, the thin film 520 is provided by another coating apparatus 552 to the foil 504. The coating apparatus 552 provides the thin film by means of extrusion or die coating. Another embodiment is provided of the heating sub-system. The other embodiment of the heating sub-system comprises a roll 554 which comprises a resistive heating element 514 for locally heating up a portion of the roll 554. The roll 554 is in contact with the foil 504 and the foil 504 is locally heated up by the area of the roll 554 that is locally heated up by the resistive heating element 514. The roll 554 touches the foil 504 before the location where the thin film recedes when the roll-to-roll coating system is in operation.

Fig. 6 schematically shows a method 600 of treating a thin film of a coating liquid applied to a substrate for redistributing the coating liquid along a substrate or for depositing a patterned coating on the substrate. The method 600 comprises the stages of applying 602 a thin film of the coating liquid to the substrate that comprises partially-wettable areas, the applying of the thin film being performed by a coating apparatus being arranged for at least temporarily providing the thin film of the coating liquid on partially-wettable areas, the partially-wettable areas are partially-wettable with respect to the coating liquid; and locally heating 604 the thin film or the substrate at a specific position at least within one of the partially-wettable areas, wherein the local heating being performed before the thin film recedes from the one of the partially-wettable areas, and the locally heating is performed to obtain controlled redistribution the thin film or the localized deposition of a material or a portion of the coating liquid at the specific position.

In summary, a method of and a system for treating a thin film of a coating liquid being applied to a substrate for redistributing the coating liquid along a substrate in a controlled fashion or for depositing a patterned coating on the substrate are provided. The method comprises the stages of a) applying a thin film of the coating liquid to the substrate that comprises partially-wettable areas by a coating apparatus being arranged for at least temporarily providing the thin film on partially-wettable areas, and b) locally heating the thin film or the substrate at a specific position at least within one of the partially-wettable areas; the local heating is performed before the thin film recedes from the one of the partially-wettable areas, and the locally heating is performed to obtain controlled redistribution of the thin film or the localized deposition of a material or a portion of the coating liquid.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

The application discloses the following embodiment: 1. A method of treating a thin film of a coating liquid applied to a substrate for redistributing the coating liquid along the substrate in a controlled fashion and for depositing a patterned coating on the substrate, the method comprises the stages of obtaining the substrate and the coating liquid, the substrate comprises partially-wettable areas that are partially-wettable with respect to the coating liquid, if the coating liquid is provided on at least one partially-wettable area, a static receding contact angle of the coating liquid provided on the at least one partially-wettable area is in between 5 and 150 degrees, the coating liquid comprises a deposition material and a liquid, the deposition material is a material that has at least one of the following characteristics: i) a portion of the deposition material directly deposits on the substrate on the specific position when the liquid of the coating liquid at least partly evaporates, ii) before or after being deposited, the deposition material chemically reacts under the influence of heat or light , and, iii) before or after being deposited, the deposition material changes under the influence of heat or light towards a solid material, applying a thin film of the coating liquid to the substrate, the applying of the thin film being performed by a coating apparatus being arranged for at least temporarily providing the thin film of the coating liquid on at least one of the partially-wettable area, and the method comprises one of the subsequent stages: deforming the thin film by locally heating the thin film, the substrate or an object supporting the substrate in case of a thin foil substrate, wherein a specific position within at least one of the partially-wettable areas is heated, the local heating is performed before the thin film recedes from the one of the partially-wettable areas, rupturing the thin film by locally heating the thin film, the substrate or an object supporting the substrate in case of a thin foil substrate, wherein a specific position within at least one of the partially-wettable areas is heated, the local heating is performed before the thin film recedes from the one of the partially-wettable areas, locally accelerating a receding contact line of the coating liquid by locally heating the thin film, the substrate or an object supporting the substrate in case of a thin foil substrate, wherein a specific position within at least one of the partially-wettable areas is heated, the local heating is performed before the thin film recedes from the one of the partially-wettable areas, depositing the deposition material at a specific position by locally heating the thin film, the substrate or an object supporting the substrate in case of a thin foil substrate, wherein the specific position within at least one of the partially-wettable areas is heated, the local heating is performed before the thin film recedes from the one of the partially-wettable areas. 2. A method according to embodiment 1, wherein, if the coating liquid is provided on at least one partially-wettable areas, the static receding contact angle of the liquid is in between 20 and 50 degrees. 3. A method according to embodiment 1 further comprising the stage of relatively moving the substrate with respect to the specific position. 4. A method according to embodiment 3, wherein in the stage of relatively moving the substrate with respect to the specific position, the speed of the relative movement is larger than an ambient-temperature dewetting speed of the coating liquid applied on the partially-wettable areas, or the speed of the relative movement is larger than an elevated-temperature dewetting speed of the coating liquid applied on the one of the partially-wettable areas. 5. A method according to any one of the embodiments 3 to 4, when directly or indirectly referring to embodiment 3, wherein a movement speed of the stage of relatively moving the substrate with respect to the specific position and an amount of heat which is applied to the thin film or to the substrate in the stage of locally heating the thin film or the substrate are selected such that the liquid of the coating liquid which remains at the specific position after receiving the heat evaporates. 6. A method according to any one of the embodiments 3 to 4, when directly or indirectly referring to embodiment 3, wherein an movement speed of the stage of relatively moving the substrate with respect to the specific position and an amount of heat which is applied to the thin film of the substrate in the stage of locally heating the thin film or the substrate are further selected such that the liquid of the coating liquid which remains at the specific position after receiving the heat is left behind. 7. A method according to any one of the embodiments 3 to 6, when directly or indirectly referring to embodiment 3, wherein, in the stage of relatively moving the substrate with respect to the specific position, the substrate is a foil and the foil is moved in a roll-to-roll configuration, in the roll-to-roll configuration the foil is provided on a first rotatable roll which provides the foil to the coating apparatus and after the locally heating of the foil or the thin film of the coating liquid, the foil is rolled up on a second rotatable roll. 8. A method according to any one of the embodiments 1 to 7, wherein the coating liquid comprises poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate). (PEDOT:PSS). 9. A system for treating a thin film of a coating liquid being applied to a substrate for redistributing the coating liquid along a substrate in a controlled fashion and for depositing a patterned coating on the substrate, the coating liquid and the substrate being part of a material system wherein the substrate comprising partially-wettable areas that are partially-wettable with respect to the coating liquid, if the coating liquid is provided on at least one partially-wettable areas, a static receding contact angle of the coating liquid provided on the at least one partially-wettable area is in between 5 and 150 degrees, the coating liquid comprising a deposition material and a liquid, the deposition material is a material that having at least one of the following characteristics: i) a portion of the deposition material directly deposits on the substrate on the specific position when the liquid of the coating liquid at least partly evaporates, ii) before or after being deposited, the deposition material chemically reacts under the influence of heat or light , and, iii) before or after being deposited, the deposition material changes under the influence of heat or light towards a solid material, the system comprising: a coating apparatus being configured for applying a thin film of the coating liquid to the substrate and for at least temporarily providing the thin film of the coating liquid on at least one of the partially-wettable areas, a heating sub-system being arranged to locally heating the thin film or the substrate or an object supporting the substrate in case of a thin substrate, at a specific position at least within one of the partially-wettable areas for deforming the thin film, rupturing the thing film, locally accelerating a receding contact line of the coating liquid, or depositing the deposition material at the specific position, the heating subsystem being configured for locally heating the specific position before the thin film recedes from the one of the partially-wettable areas. 10. A system according to embodiment 9, wherein the heating sub-system comprises at least one of: i) a source of electromagnetic radiation for emitting electromagnetic radiation towards the specific position, wherein a wavelength of the electromagnetic radiation is selected to be absorbed by at least one of the thin film or the substrate or the object supporting the substrate, and ii) a resistive heating element arranged at a position close to or in contact with the substrate for locally heating the substrate. 11. A system according to embodiment 10, wherein, when the heating subsystem comprises a source of electromagnetic radiation, the source of electromagnetic radiation is arranged for changing an emission direction of the electromagnetic radiation in response to a control signal such that the specific position moves with respect to the substrate. 12. A system according to embodiment 9 or 10 further comprising movement elements effecting a translation and/or a rotation of the substrate for relatively moving the substrate with respect to the specific position at which the heating sub-system provides the heat. 13. A system according to any one of the embodiments 9 to 12 further comprising a roll-to-roll foil coating system, wherein the substrate is formed by a foil, the roll-to-roll foil coating system comprises a first rotatable roll for providing the foil and a second rotatable roll for collecting the foil after the foil has been coated and locally heated by, respectively, the coating apparatus and the heating sub-system. 14. A system according to embodiment 13, wherein the foil coating roll-to-roll system comprises a third rotatable roll being arranged at a location to contact the foil where the thin film is still present at the foil.

Claims

A method (600) for treating a thin film of a coating liquid applied to a substrate for redistributing the coating liquid in a controlled manner and for depositing a patterned coating on the substrate, the method comprising the steps: obtaining the substrate and the coating fluid, the substrate comprises partially wettable areas that are partially wettable with respect to the coating fluid, a static recoil contact angle of the coating fluid, if it is applied to the at least one of the partially is wettable areas, between 5 and 150 degrees, the coating liquid comprises deposition material and a liquid, the deposition material is a material with at least one of the following properties: i) a part of the deposition material deposits directly on the substrate at the specific position if the liquid of the coating liquid evaporates at least partially, ii) for or after depositing, the depositing material exhibits a chemical reaction under the influence of heat or light, and, iii) before or after depositing, the depositing material changed into a solid material under the influence of heat or light, applying (602) a thin film of the coating liquid on the substrate, the application of the thin film is carried out by a coating device adapted to at least temporarily apply the thin film of the coating liquid to the substrate comprising the partially wettable regions, the partially wettable regions are partially wettable with respect to the coating liquid, and the method comprises one of the following steps: deforming the thin film by locally heating the thin film, the substrate or an object supporting the substrate in the case of a thin film substrate, wherein a specific position within at least one of the partially wettable areas is heated, the room heating is performed before the thin film withdraws from the at least one of the partially wettable regions, breaking the thin film by locally heating the thin film, the substrate or an object supporting the substrate in the case of a thin film substrate wherein a specific position within at least one of the partially wettable regions is heated, local heating is performed before the thin film withdraws from at least one of the partially wettable regions, locally accelerating a receding contact line of the coating liquid by the local heating of the thin film, the substrate or an object supporting the substrate in the case of a thin film substrate, in which a specific position is heated within at least one of the partially wettable areas, the local heating is performed before the thin film is withdraws from the at least one of the partially wettable regions, depositing the deposition material at a specific position by locally heating the thin film, the substrate, or an object supporting the substrate in the case of a thin film substrate, wherein the specific position within at least one of the partially wettable regions is heated, local heating is performed before the thin film withdraws from at least one of the partially wettable regions.

A method (600) according to claim 1, wherein the static recoil contact angle of the coating liquid on the at least, if applied to the at least one of the partially wettable regions, is between 5 and 150 degrees.

A method (600) according to claim 1 further comprising the step of relatively moving the substrate with respect to the specific position.

A method (600) according to claim 3, wherein, in the step of relatively moving the substrate with respect to the specific position, the speed of relative movement is greater than ambient temperature dehumidification rate of the coating liquid applied to the coating liquid. partially wettable areas, or the relative movement speed is greater than increased temperature dehumidification rate of the coating fluid applied to the at least one of the partially wettable areas.

A method (600) according to any of the preceding claims 3 to 4, as far as direct or indirect reference is made to claim 3, wherein a speed of movement of the step of relatively moving the substrate with respect to the specific position and an amount of heat supplied to the thin film or to the substrate in the step of locally heating the thin film or substrate is selected such that the liquid of the coating liquid evaporates at the specific position after receiving the warmth.

A method (600) according to any of the preceding claims 3 to 4, as far as direct or indirect reference is made to claim 3, wherein a speed of movement of the step of relatively moving the substrate with respect to the specific position and an amount of heat applied to the thin film or to the substrate in the step of locally heating the thin film or substrate is selected such that the liquid of the coating liquid remains behind at the specific position.

A method (600) according to any one of the preceding claims 3 to 6, as far as direct or indirect reference is made to claim 3, wherein, in the step of relatively moving the substrate with respect to the specific position, the substrate is a foil and the foil is moved by means of a roll-on-roll configuration, in the roll-on-roll configuration the foil is delivered on a first rotatable roll which the foil delivers to the coating device and after the local heating the film or the thin film of the coating liquid, the film is rolled up on a second rotatable roll.

A method (600) according to any of the preceding claims, wherein the coating liquid comprises poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate) (PEDOT: PSS).

A system (500, 550) for treating a thin film (520) of a coating fluid (508) applied to a substrate (504) for redistributing the coating fluid (508) in a controlled manner and for depositing a patterned coating on the substrate (504), the coating fluid and the substrate belong to a material system in which the substrate comprises partially wettable regions that are partially wettable with respect to the coating fluid, the static recoil contact angle of the coating liquid, if applied to the at least one of the partially wettable areas, is between 5 and 150 degrees, the coating liquid comprises deposit material and a liquid, the deposit material is a material with at least one of the following properties: i) a part of the deposit material deposits directly on the substrate at the specific position if the liquid of the coating liquid is at least partially calibration evaporated, ii) before or after deposition, the deposition material exhibits a chemical reaction under the influence of heat or light, and, iii) before or after deposition, the deposition material changed into a solid material under the influence of heat or light, The system (500, 550) comprises: a coating device which is adapted to apply the coating liquid (508) to the substrate (504) and to at least temporarily apply the coating liquid (508) to the at least one of the partially wettable regions, a heating subsystem (518, 514) for locally heating at a specific position in at least one of the partially wettable regions of the thin film (520), the substrate (504) or an article (554) covering the substrate ( 504) supports in the case of a thin substrate for deforming the thin film, breaking the thin film, locally accelerating a receding contact line of the coating liquid, or depositing the deposit material at the specific position, the heating subsystem (518, 514) is arranged to perform local heating of the specific position before the thin film (520) deviates from the at least one of the partially wettable regions.

A system (500, 550) according to claim 9, wherein the heating subsystem (514, 518) comprises at least one of the following: i) a source (518) of electromagnetic radiation for radiating the electromagnetic radiation (516) to the specific position, wherein a wavelength of the electromagnetic radiation is selected to be absorbed by at least one of: the thin film (520), the substrate (504) or the object (514) supporting the substrate (504), and ii) an ohmic heating element (514) disposed at a position close to the substrate (504) or at a position where it is in contact with the substrate (504) for locally heating the substrate (504).

A system (500, 550) according to claim 10, wherein, if the heating subsystem comprises a source (518) of electromagnetic radiation, the source (518) of the electromagnetic radiation is adapted to change the direction of emission of the electromagnetic radiation in response on a control signal such that the specific position moves relative to the substrate (504).

A system (500, 550) according to claim 9 or 10, further comprising elements for effecting a translation and / or rotation of the substrate for moving the substrate with respect to the specific position where the heating subsystem (514, 518) supplies the heat.

A system (500, 550) according to any of claims 9 to 12 further comprising a roll-on-roll film coating system, wherein the substrate (504) is a film, and the roll-on-roll film coating system comprises a first rotatable roll (502) for supplying the film and a second rotatable roll (512) for collecting the film after the film has been coated and locally heated by, respectively, the coating device and the heating part system (514, 518) ).

A system (500,550) according to claim 13, wherein the roll-on-roll film coating system comprises a third rotatable roll which is arranged at a location to contact the film where the thin film is still present on the film .