CN116445879A - Processing system, evaporator, and method for coating flexible substrates - Google Patents

Abstract

A processing system (100) for coating a flexible substrate and a method of coating a flexible substrate are described. In particular, the evaporator (30) and method of operating the evaporator are described. The evaporator (30) comprises a crucible arrangement (35) having a number R of adjacent rows of crucibles (350), each of the crucibles having an induction coil (36) surrounding an individual crucible. Furthermore, the evaporator (30) includes a power supply (40) for supplying a number N _f of alternating currents of different frequencies f _N to adjacent induction coils respectively, where N _f =3 or N _f = R+1.

Description

Processing system, evaporator, and method for coating flexible substrates

technical field

Embodiments of the present disclosure relate to processing systems and methods for processing flexible substrates, particularly for processing flexible substrates in a roll-to-roll process under vacuum. In particular, embodiments of the present disclosure relate to processing systems and methods for coating flexible substrates by evaporation of coating materials.

Background technique

The handling of flexible substrates such as plastic films or foils is in high demand in the packaging industry, the semiconductor industry and other industries. In particular, roll-to-roll (R2R) processing of flexible substrates has attracted much attention due to high throughput at low cost. In particular, roll-to-roll deposition systems have attracted much attention in the manufacture of thin-film batteries, the display industry, and the photovoltaic (PV) industry. For example, the growing demand for flexible touch panel elements, flexible displays and flexible PV modules creates a growing need to deposit suitable layers in R2R coaters.

There is a continuing need for improved R2R processing systems, especially in terms of processing quality, processing time, and processing efficiency. To achieve high-quality coatings on flexible substrates, various challenges related to flexible substrate transfer and uniform layer deposition must be navigated. For example, providing proper substrate-roll contact during substrate transfer under vacuum conditions and coating flexible substrates with high-quality layers with improved uniformity, improved product lifetime, and lower number of defects per surface area remain challenging.

Accordingly, there is a continuing need to provide solutions that can be used to reduce or overcome at least some of the disadvantages of the prior art.

Contents of the invention

In view of the above, there are provided an evaporator, a method of operating an evaporator, a processing system for coating a flexible substrate and a method of coating a flexible substrate according to the independent claims. Further aspects, advantages and features are evident from the dependent claims, the description and the figures.

According to one aspect of the present disclosure, an evaporator is provided. The evaporator comprises an arrangement of crucibles having a number R of adjacent rows of crucibles. Each of the crucibles has an induction coil surrounding the individual crucible. Furthermore, the evaporator comprises a power supply for separately supplying a number N _f of alternating currents of different frequencies f _N to adjacent induction coils, where N _f =3 or N _f =R+1.

According to another aspect of the present disclosure, there is provided an evaporator comprising a crucible arrangement having a number R of adjacent rows of crucibles. Each of the crucibles has an induction coil surrounding the individual crucible. In addition, the evaporator comprises a power supply for separately supplying a number N _f of alternating currents of different frequencies f _N to adjacent induction coils, where N _f =3 or N _f =R+1. The number N _f of different frequencies f _N comprises _a first frequency f ₁ selected from the first range 5 kHz ≤ f ₁ ≤ 20 kHz, a second frequency f 2 selected from the second range 10 kHz ≤ f ₂ ≤ 30 kHz and a third frequency f selected from the third range A third frequency f ₃ of 15 kHz ≤ f ₃ ≤ 50 kHz. Furthermore, at least one of the following is applied: at least two of the different frequencies f _N of the number N _f are modulated with respect to at least one of the following: their amplitude, phase and frequency; and by N _f different The oscillating circuits provide a number _Nf of different frequencies f _N , each oscillating circuit having an inductor and a capacitor, wherein the capacitances C _N of the respective capacitors of the different oscillating circuits are different from each other.

According to another aspect of the present disclosure, a method of operating an evaporator is provided. The evaporator comprises a crucible arrangement having a number R of adjacent rows of crucibles. Each of the crucibles has an induction coil surrounding the individual crucible. The method comprises supplying a number N _f of alternating currents of different frequencies f _N to adjacent induction coils, respectively, where N _f =3 or N _f =R+1, and where R≧2.

According to another aspect of the present disclosure, a processing system for coating a flexible substrate is provided. The processing system includes a take-up chamber housing supply rolls for supplying flexible substrates, take-up rolls for storing flexible substrates after processing, and a plurality of rolls for guiding the flexible substrates along a substrate transport path. guide rollers. Additionally, the processing system includes a processing chamber housing an evaporator for evaporating material to be deposited on the flexible substrate. Additionally, the processing system includes a coating roller for guiding the flexible substrate through the evaporator. The evaporator is an evaporator according to any of the embodiments described herein.

According to another aspect of the present disclosure, a method of coating a flexible substrate is provided. The method comprises using at least one of: an evaporator according to any embodiment described herein, a method of operating a evaporator according to any embodiment described herein, and a treatment system according to any embodiment described herein .

Embodiments are also directed to apparatus for performing the disclosed methods and include apparatus components for performing each described method aspect. These method aspects may be performed by hardware components, by a computer programmed with appropriate software, by any combination of the two or in any other manner. Furthermore, embodiments according to the present disclosure also relate to methods for operating the device. The method for operating the device includes method aspects for performing each function of the device.

Description of drawings

So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the present disclosure, briefly summarized above, can be had by referring to the embodiments. The drawings relate to various embodiments of the present disclosure and are described below:

Figure 1 shows a schematic diagram of a processing system according to embodiments described herein;

Figure 2 shows a schematic diagram of a portion of a processing system according to further embodiments described herein;

Figure 3 shows a schematic diagram of a longitudinal sectional view of a coating drum according to embodiments described herein;

Figure 4 shows a sectional view along the line A-A indicated in Figure 3;

Figure 5 shows a schematic top view of a coating drum with a gas outlet arrangement according to embodiments described herein;

Figure 6 shows a schematic view of the enlarged portion indicated in Figure 4 of a coating drum according to embodiments described herein;

Figures 7 to 9 show schematic cross-sectional views of a part of the enlarged portion indicated in Figure 6 of a coating cylinder according to embodiments described herein;

Figures 10 to 12 show schematic top views of coating drums with different gas outlet densities according to embodiments described herein;

Figures 13 to 15 show schematic top views of coating drums with different outlet diameters according to embodiments described herein;

Figures 16 and 17 show schematic longitudinal cross-sectional views of a coating drum with a coolant supply according to embodiments described herein;

Figure 18 shows a schematic side cross-sectional view of an evaporator according to embodiments described herein;

Figure 19 shows a schematic top view of an evaporator according to embodiments described herein;

Figure 20 illustrates a portion of a vaporizer showing individual crucibles surrounded by individual induction coils connected to individual power sources, according to embodiments described herein;

Figure 21 shows a block diagram illustrating a method of operating an evaporator according to embodiments described herein; and

Figure 22 shows a detailed schematic cross-sectional view of a crucible according to embodiments described herein;

Detailed ways

Reference will now be made in detail to various embodiments of the present disclosure, one or more examples of which are illustrated in the drawings. In the following description of the drawings, the same reference numerals refer to the same components. Only the differences with respect to the individual embodiments are described. Each example is provided by way of explanation of the disclosure, and not meant to be a limitation of the disclosure. Additionally, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield a further embodiment. The description is intended to cover such modifications and variations.

With exemplary reference to FIG. 1 , a processing system 100 in accordance with the present disclosure is described. In particular, the processing system 100 described herein is a roll-to-roll deposition system for coating flexible substrates.

According to an embodiment, which can be combined with any other embodiment described herein, the processing system 100 comprises a winding chamber 10 and a processing chamber 20 . The winding chamber 10 accommodates a plurality of rollers, providing a winding system for transporting the flexible substrate 1 to be processed. In particular, a supply roll 11 for supplying the flexible substrate 1 , a take-up roll 12 for storing the processed flexible substrate, and a plurality of guide rolls 13 are provided in the winding chamber 10 . Furthermore, at least one of the following may be provided: one or more stretching rolls 14, one or more tension rolls 15, and one or more nip rolls 16. In addition, a coating cylinder 17 is provided. The coating drum 17 is arranged and configured to guide the flexible substrate 1 from the winding chamber 10 into the processing chamber 20 . As exemplarily shown in FIG. 1 , a plurality of rolls of the processing system 100 are provided from the supply roll 11 to the take-up roll 12 or from the take-up roll 12 to the supply roll 11 (that is, the upper take-up roll 12 shown in FIG. is a supply roller and the supply roller 11 may be a take-up roller) substrate transport path. In other words, the supply roller 11 and the take-up roller 12 can operate in a clockwise rotation direction as well as a counterclockwise rotation direction.

In particular, referring exemplarily to FIG. 1 , according to an embodiment which may be combined with any other embodiment described herein, the substrate transport path may be provided by: a first stretching roller 141 arranged downstream of the supply roller 11 and Upstream of the treatment machine 60; one or more guide rolls 13, arranged downstream of the pretreatment machine 60 and upstream of the second stretching roll 142; second stretching rolls 142, arranged downstream of the pretreatment machine 60 and at the coating Upstream of the cylinder 17; the coating cylinder 17, arranged downstream of the second stretching roller 142 and upstream of the finisher 70; one or more guide rollers 13, arranged downstream of the finisher 70 and between the tension roller 15 upstream; a tension roller 15, arranged downstream of the layer measuring system 80 and upstream of the pivot arm 18; one or more guide rollers 13, arranged downstream of the tension roller 15 and upstream of the third stretching roller 143; third a stretching roller 143 , arranged downstream of the tension roller 15 and mounted to a pivot arm; one or more guide rollers 13 , arranged downstream of the third stretching roller 143 and upstream of the take-up roller 12 .

In this disclosure, the terms "upstream of" and "downstream of" mean along the transport path (as exemplified in FIG. 1 ) in the substrate transport direction T from supply roll 11 to take-up roll 12 shown), the position of the corresponding part relative to another part.

It should be understood that one or more different substrate transport paths may be provided than the different substrate transport paths shown in FIG. 1 . For example, as exemplarily shown in FIG. 2 , the substrate transfer paths may be different for different substrates. In other words, depending on the substrate employed, the substrate transport path can be optimized with regard to the free span distance between subsequent rollers and/or the wrapping angle of the substrate around the rollers. For example, by providing an additional guide roller 13A, as exemplarily shown in FIG. 2 , the wrapping angle of the second substrate 1B around the coating drum can be increased compared to the wrapping angle of the first substrate 1A around the coating drum. For example, when a PET substrate is used, the transfer path for the first substrate 1A shown in FIG. 2 may be used, and when an OPP substrate is used, another transfer path for the second substrate shown in FIG. 2 may be used. for beneficial.

In this disclosure, a "supply roll" may be understood as a roll on which flexible substrates to be processed are stored. Accordingly, a "take-up roll" as described herein may be understood as a roll adapted to receive a processed flexible substrate. In addition, it should be noted that a "supply roll" may also be called an "unwinder", and a "take-up roll" may also be called a "rewinder". Figure 1 shows a supply roll 11 on which a flexible substrate is wound and an empty take-up roll 12. The dashed circle around the take-up roll 12 shown in FIG. 1 indicates a situation where the flexible substrate is completely unwound from the supply roll 11 and completely rewound on the take-up roll 12 . According to an embodiment, which may be combined with any other embodiment described herein, the supply roll 11 and the take-up roll 12 are drive rolls. A drive roller may be understood as a roller provided with a drive or motor for actively moving or rotating the respective roller. Typically, the drive roll is controllable to provide a predetermined torque and/or a predetermined rotational speed. For example, an AC drive may be coupled to the drive roll as described herein. Multiple AC drives of multiple drive rolls described herein may be synchronized. It should be understood that the torque and/or rotational speed of the drive roll may be controllable such that variable torque and/or speed may be provided.

In this disclosure, a "flexible substrate" may be understood as a bendable substrate. For example, a "flexible substrate" may be a "foil" or a "roll". In this disclosure, the term "flexible substrate" and the term "substrate" may be used synonymously. For example, the flexible substrates described herein may include materials like: BOOP, CPP, HDPE, LDPE, PA (Nylon), PET, PVC (especially unplasticized PVC), PE, PI, PU, TaC, OPP, one or more metals, paper, a combination of the above, or any other material suitable for coating using evaporation. Furthermore, it should be noted that already coated substrates can also be used. Typically, the substrate thickness T _s may be 1 μm ≤ T _s ≤ 200 μm, especially 5 μm ≤ T _s ≤ 100 μm, more particularly 5 μm ≤ T _s ≤ 50 μm. The substrate length L _s may be L _s ≥ 10000 m, in particular L _s ≥ 20000 m, more in particular L _s ≥ 25000 m. The substrate width W _s may be 0.5 m ≤ W _s ≤ 5 m, in particular 1 m ≤ W _s ≤ 3 m.

In the present disclosure, a "guide roller" may be understood as a roller adapted to guide a flexible substrate while it is being transported. Typically, the "guide rolls" referred to herein are passive rolls. A passive roller is to be understood as a roller which is not provided with a drive for actively moving or rotating the roller. During operation, the passive roller can rotate by the friction of the flexible substrate in direct contact with the outer roller surface. In other words, a driven roller is a non-driven roller that turns by contact with a passing substrate. As exemplarily shown in FIG. 1 , a plurality of guide rollers 13 are generally provided along a transfer path of the flexible substrate from the supply roller 11 to the take-up roller 12 . In particular, in the roll-up system, guide rollers guide and bend the flexible substrate along the substrate transport path.

According to an embodiment, which may be combined with any other embodiment described herein, one or more guide rollers 13 may be configured as tension measuring rollers. A tension measurement roller may be understood as a roller configured to measure the tension of a flexible substrate during substrate transport. Providing a tension measuring roller may be beneficial in monitoring substrate tension during operation.

In the present disclosure, a "spreading roll" may be understood as a roll adapted to provide a defined tension in the width direction of the flexible substrate to be coated. In particular, the stretching rollers may be configured to stretch the flexible substrate, for example by having a curved surface along the length of the stretching roller, creating a tensioning effect in the width direction of the flexible substrate, thereby stretching the flexible substrate. In other words, the flexible substrate can be stretched in a direction parallel to the rotation axis of the stretching rollers. An advantage of providing stretching rollers is that wrinkling during substrate transport can be reduced or even eliminated. It should be understood that various types of stretching rolls may be provided, such as bowed rolls, expandable rolls, curved bar rolls, grooved rolls or the like.

According to one example, the stretching rollers may include electrical heating means for supporting or enhancing the mechanical stretch introduced by the stretching rollers to the flexible substrate. Referring exemplarily to FIG. 1 , according to an embodiment which may be combined with any other embodiment described herein, a plurality of stretching rollers 14 are provided along the transport path of the flexible substrate from the supply roller 11 to the take-up roller 12 . In particular, a first stretching roll 141 may be provided downstream of the supply roll 11 and upstream of the pretreatment machine 60 . A second stretching roll 142 may be provided downstream of the pretreatment machine 60 and upstream of the coating drum 17 . A third stretching roll 143 may be provided downstream of the tension roll 15 and upstream of the take-up roll 12 . In particular, third stretching roller 143 may be mounted to pivot arm 18 as described herein. According to an embodiment, which may be combined with any other embodiment described herein, the first stretching roller 141 and the second stretching roller 142 are passive rollers. The third stretching roll 143 may be a driving roll.

In this disclosure, a "tension roller" may be understood as a roller adapted to increase the tension of a flexible substrate. For example, the tension roller may include a cooling device for cooling the flexible substrate guided by the tension roller. Accordingly, the flexible substrate can be tensioned by thermal shrinkage. According to another example, the tension roller may be coupled to an actuator for moving the tension roller such that displacement of the tension roller causes tension in the substrate. It should be understood that other configurations of tension rollers suitable for increasing substrate tension may be employed.

In this disclosure, a "roller" may be understood as a roller configured to press a flexible substrate against another roller. Accordingly, the rollers may be coupled to actuators, such as hydraulic or pneumatic actuators, for pressing the rollers against the other roller. Referring exemplarily to FIG. 1 , according to an embodiment, which may be combined with any other embodiment described herein, a nip roll 16 may be arranged and configured for pressing a flexible substrate onto a substrate stored on a supply roll 11 . The roll 16 may be movable relative to the supply roll 11 by employing an actuator 161 coupled to the roll 16 as indicated schematically by the double-headed arrow.

In this disclosure, a "coating drum" may be understood as a drum or roller having a substrate support surface for contacting a flexible substrate during processing. In particular, the coating drum may be rotatable about an axis of rotation and may comprise a substrate guide area. Typically, the substrate guiding region is a curved substrate support surface of the coating drum, eg a cylindrically symmetric surface. The curved substrate support surface of the coating drum may be adapted to (at least partially) contact the flexible substrate during operation. The substrate guiding region may be defined as the angular range of the rollers at which the substrate contacts the curved substrate support surface during guiding the substrate, and may correspond to the wrap angle of the rollers. For example, the wrap angle of the rolls may be 120° or greater, especially 180° or greater, or even 270° or greater. According to some embodiments, which may be combined with other embodiments described herein, the coating drum is cylindrical and has a length L of 0.5m≤L≤8.5m. In addition, the coating drum may have a diameter D of 1.0m≤D≤3.0m. Accordingly, the coating drum is advantageously configured for guiding and transporting flexible substrates having a large width.

According to an embodiment, which may be combined with any other embodiment described herein, the substrate supporting surface of the coating drum has a coating comprising an electronegative polymer. "Negatively charged polymer" may be understood as a polymer having negatively charged properties. Typically, the coating is provided over the entire support surface. In particular, the coating has a constant thickness, for example a thickness T selected from the range 2.5 μm≦T≦15 μm. Providing a coating with a thickness T selected from the range 2.5 μm < T < 15 μm may be beneficial to ensure sufficient capacitance to ensure sufficient pinning force between the flexible substrate and the coated support surface of the coating drum.

According to some embodiments, which may be combined with other embodiments described herein, the coating provided on the substrate support surface of the coating drum has triboelectric properties. In other words, the electronegative polymer can be configured to generate an electrostatic charge through frictional contact with the flexible substrate. In particular, negatively charged polymers, such as fluoropolymers, can be configured to generate a mirror charge on the surface of the flexible substrate during booting through the triboelectric effect. The triboelectric effect (also known as triboelectrification) is a type of contact electrification in which certain materials become charged after frictional contact with a different material. In other words, the triboelectric effect can be described as the transfer of electrical charges (electrons) from one material to another following a frictional or sliding contact. The overall charge transfer between two materials is defined by the difference in charge affinity between the surfaces of the two contacting materials.

Accordingly, a coating comprising an electronegative polymer is provided on the support surface of the coating drum, which coating is configured to generate a mirror image charge on the surface of the flexible substrate in contact with the active device during substrate guiding, which advantageously improves the flexibility. Adhesion of the substrate to the coating drum. In other words, providing a coating with triboelectric properties on the support surface of the coating drum beneficially provides charge transfer between the coating and the flexible substrate such that a constant and uniform charge between the flexible substrate and the coating drum can be ensured. The contact force (also known as pinning force or holding force). Furthermore, exploiting the triboelectric effect advantageously allows for reduced slippage between the flexible substrate and the coating provided on the support surface of the coating drum.

For example, the substrate materials described herein have a charge affinity CA of -90nC/J≤CA≤-40nC/J. For example, PET has a charge affinity CA of CA ≈ −40 nC/J, BOOP has a charge affinity CA of CA ≈ −85 nC/J, and LDEP, HDPE, and PP have a charge affinity CA of CA ≈ −90 nC/J. The coatings described herein comprising an electronegative polymer, in particular comprising or consisting of a fluoropolymer, in particular comprising or consisting of PTFE and/or PFA have a CA ≈ -190 nC/ The charge affinity of J for CA.

Accordingly, the coatings described herein that are provided on the support surface of the coating roll advantageously ensure that the coated coating roll is negatively charged compared to the substrate, even in the absence of an externally applied electric field. Accordingly, it should be understood that, according to embodiments, which may be combined with other embodiments herein, the coating on the support surface of the coating drum may be configured to provide a charge affinity differential relative to a flexible substrate to be guided through the coating drum. ΔCA. In particular, the charge affinity difference ΔCA between the coating and the substrate may be 50nC/J≤ΔCA≤200nC/J, especially 100nC/J≤ΔCA≤150nC/J.

According to an embodiment, which may be combined with any other embodiment described herein, the electronegative polymer may be a dielectric. In particular, an electronegative polymer can be an electrically insulating material that can be polarized. For example, the negatively charged polymer may be a fluoropolymer, especially an elastomeric fluoropolymer, eg comprising perfluoroalkoxy polymer (PFA) and/or polytetrafluoroethylene (PTFE). In particular, the fluoropolymer may consist of PFA or PTFE. Coatings comprising or consisting of fluoropolymers such as PFA or PTFE advantageously provide coatings with very high dielectric breakdown strength. Furthermore, coatings comprising or consisting of fluoropolymers such as PFA or PTFE advantageously provide low coefficients of friction, especially ultra-low coefficients of friction. Accordingly, a low wear rate of the coating (eg, comparable to steel) may be beneficially provided, thereby ensuring coating life. In other words, the fluoropolymer coating provides a fluoropolymer coating surface that advantageously provides an excellent level of low friction performance that reduces effective coating wear.

According to an embodiment, which may be combined with any other embodiment described herein, the coating provided on the support surface of the coating drum may have a friction coefficient μ of μ≤0.1, in particular a friction coefficient μ of μ≤0.05. More particularly, the coefficient of friction μ of the unlubricated fluoropolymer may be μ≦0.1, in particular μ≦0.05. It should be noted that local wear of coating asperities can provide highly hydrophobic hydrodynamic boundary lubrication, beneficially further reducing the coefficient of friction by a factor F of about F=10. Accordingly, an effective coating material wear rate close to the level of the inherent wear rate of steel can be advantageously achieved.

For example, according to an embodiment ^which may ^be combined with any other embodiment described herein, the coating provided on the support ^surface of the coating drum may have ^a The wear rate constant ka. In other words, the coating may be configured to have a wear rate constant ka selected from the range of 0.4×10 ^-7 MPa ^-1 ≤ ka ≤ 2.0×10 ^-6 MPa ^-1 . The wear rate constant ka is the dimensionless wear rate constant k divided by the hardness [MPa], ie ka[MPa ⁻¹ ]=k/hardness [MPa].

According to some embodiments, which may be combined with other embodiments described herein, the coating provided on the support surface of the coating drum has a breakdown field strength BFS of 2.0MV/cm≦BFS≦30MV/cm. For example, a PFA coating with a thickness T of T=5 μm has a BFS of 2.0 MV/cm when an electric field of 300 V is applied. A PTFE coating with a thickness T of T = 10 μm has a BFS of 24 MV/cm when an electric field of 300 V is applied.

Providing a coating drum with a coating comprising an electronegative polymer as described herein advantageously provides improved contact of the flexible substrate with the coating drum during substrate transport. Accordingly, using a coating roll as described herein, a substantially constant and uniform contact force between the flexible substrate and the coating roll can be achieved such that holding or adhesion of the flexible substrate to the coating roll can be improved. Contact force may also be referred to as holding force. Furthermore, by employing a coating roll with a coating as described herein, heat transfer from the flexible substrate to the coating roll can be improved, which is beneficial for processing heat sensitive flexible substrates, especially thin polymer flexible substrates. The improved heat transfer results from the fact that when the flexible substrate is guided with the coating roller of the present disclosure, direct contact of the substrate with the coated support surface can be provided for substantially the entire contact surface. In other words, areas with gaps (down to the microscopic scale) between the flexible substrate and the coated support surface can be reduced or substantially eliminated.

Referring exemplarily to FIG. 1 , according to an embodiment, which may be combined with any other embodiment described herein, a coating drum 17 is arranged and configured for guiding a flexible substrate through an evaporator 30 to deposit evaporated material on the substrate. . Typically, coating roll 17 is a drive roll as described herein.

According to an embodiment, which may be combined with any other embodiment described herein, the coating drum 17 comprises a main body 171 having a plurality of gas supply slits 173 , as exemplarily shown in FIGS. 3 to 5 . A plurality of gas supply slits 173 are provided in the outer surface 172 of the main body 171 . Furthermore, a plurality of gas supply slits 173 extend in the direction of the central rotation axis 17C of the coating drum 17 . In addition, the coating drum 17 may include a sleeve 174 circumferentially provided around the main body 171 and in contact with the main body 171 . The sleeve 174 may include a plurality of gas outlets 175 provided above the plurality of gas supply slits 173 . In particular, as exemplarily shown in FIGS. 4 and 5 , the plurality of gas outlets 175 may be provided directly above the plurality of gas supply slits 173 . More particularly, an inner surface 174I of a sleeve 174 having a plurality of gas outlets 175 is generally in contact with an outer surface 172 of a body 171 having a plurality of gas supply slits 173 . Accordingly, each of the plurality of gas outlets 175 may be provided above a corresponding one of the plurality of gas supply slits 173 . Typically, the plurality of gas outlets 175 extend in a radial direction R. As shown in FIG. Additionally, the sleeve may include a metal layer 176 embedded within the isolation material 1740 . It should be understood that the provision of multiple gas supply slots 173, multiple gas outlets 175 and cooling gas supply 1710 as described herein is an optional feature of the coating cylinder.

In the present disclosure, a "metal layer embedded in an isolation material" may be understood as a metal layer surrounded by an isolation material. For example, the metal layer may have a thickness T _M selected from a range between a lower limit T _ML and an upper limit T _MU , ie T _ML ≦T _M ≦T _MU . The lower limit T _ML may be T _ML =10 μm, especially T _ML =20 μm, more particularly T _ML =30 μm. The upper limit T _MU may be T _MU =200 μm, in particular T _MU =150 μm, more in particular T _MU =100 μm.

It should be understood that the metal layers embedded within the isolation material described herein may function as electrostatic chucks. In general, an electrostatic chuck is understood as a device configured to provide an electrostatic charge for holding a substrate by electrostatic force. Accordingly, the electrostatic chuck is configured to provide an attractive force for holding the flexible substrate in contact with the curved surface of the coating drum. Accordingly, a constant and uniform contact force between the flexible substrate and the coating cylinder can be further improved.

In this disclosure, "isolating material" may be understood as an electrically isolating material. Correspondingly, "isolating material" is to be understood as a material that is not electrically conductive, eg a material that has a very low or negligible electrical conductivity. For example, the isolation material may be a ceramic material or a polymeric material.

By providing a coating roll as described herein having a sleeve comprising a metal layer embedded within a release material, an improved coating roll for transporting flexible substrates can be provided. In particular, coating rollers may offer the possibility of exploiting electrostatic interactions between the coating roller and the flexible substrate to increase the contact pressure, especially in combination with gas cooling of the flexible substrate. Furthermore, since it is possible to increase the contact pressure between the coating roller and the flexible substrate, a higher gas pressure can be used to cool the substrate, thereby improving cooling efficiency. Furthermore, the specific configuration of the coating drum with an outer surface of insulating material has the advantage that harmful effects such as leakage or arcing due to the application of an electrical potential to the coating drum can be avoided.

In the present disclosure, a "body" of a coating cylinder is to be understood as a cylindrical body, in particular a cylindrical shell of solid material. Typically, the body is made of a material with a high thermal conductivity λ, in particular λ≧50 W/(m·K), more in particular λ≧100 W/(m·K). For example, the body may be made of a material comprising copper, such as a copper alloy. It will be appreciated that the body may alternatively be made of any other suitable material having a high thermal conductivity λ.

In this disclosure, a "gas supply slit" may be understood as a slit configured for supplying gas to the plurality of gas outlets described herein. In particular, the "gas supply slits" described herein are generally provided in the outer surface of the main body and extend parallel to the central rotational axis of the coating drum. Also, cooling gas may generally be supplied from a cooling gas supply source 1710 to the "gas supply slots" described herein, as schematically shown in FIG. 2 . According to an embodiment, which may be combined with other embodiments described herein, the distance d _G between the gas supply slits in the circumferential direction may be selected from a range between a lower limit d _GL and an upper limit d _GU , ie d _GL ≤ d _G ≤ d _GU . The distance d _G is indicated schematically in FIG. 6 . The lower limit d _GL may be d _GL =4 mm, in particular d _GL =6 mm, more in particular d _GL =8 mm. The upper limit d _GU may be d _GU =10 mm, in particular d _GU =12 mm, more in particular d _GU =15 mm. For example, the distance d _G may be 10 mm.

In this disclosure, a "sleeve" may be understood as a sleeve that is in contact with the outer surface of the body described herein. Accordingly, the sleeve may be a shell disposed circumferentially around and in contact with the main body of the coating drum. Typically, the sleeve is at least partially in contact with the flexible substrate during transport of the flexible substrate. In particular, the sleeve may provide a substrate support surface as described herein. Typically, the sleeve is made of sheet metal or includes a metal layer 176 . The sleeve may have a thickness T selected from a range between a lower limit _TL and _an upper limit _TU , ie _TL≤T≤TU . The lower limit _TL may be _TL = 0.5 mm, in particular _TL = 1.0 mm, more in particular _TL = 1.5 mm. The upper limit T _U may be T _U =2.0 mm, in particular T _U =2.5 mm, more in particular T _U =3.0 mm.

In this disclosure, a "gas outlet" may be understood as an outlet configured to provide gas to the flexible substrate during transport of the substrate through the coating drum. Correspondingly, the gas outlet described herein can be understood as a gas discharge hole. The outlet diameter D _out of the gas outlet according to the present disclosure may be selected from a range between a lower limit _DL and an upper limit _DU , ie _DL ≤ D _out ≤ D _U . The lower limit _DL may be _DL = 30 μm, especially _DL = 40 μm, more particularly _DL = 60 μm. The upper limit _DU may be _DU = 150 μm, especially _DU = 100 μm, more particularly _DU = 80 μm. Typically, the gas outlets described herein are created using laser drilling methods. Laser drilling may also be referred to as laser ablation. Typically, the "gas outlet" described herein has a cylindrical inner surface, the inner diameter of which corresponds to the outlet diameter D _out of the gas outlet described herein. In other words, a "gas outlet" as described herein is to be understood as a cylindrical outlet with a constant outlet diameter _Dout along the outlet axis, generally extending in radial direction.

According to an embodiment which may be combined with other embodiments described herein, the distance d _C between adjacent gas outlets in the circumferential direction may be selected from a range between a lower limit d _CL and an upper limit d _CU , i.e. d _CL ≤ d _C ≤d _cu . The lower limit d _CL may be d _CL =4 mm, in particular d _CL =6 mm, more in particular d _CL =8 mm. The upper limit d _CU may be d _CU =10 mm, in particular d _CU =12 mm, more in particular d _CU =15 mm. For example, the distance d _C may be 10 mm. The distance d _C between adjacent gas outlets 175 in the circumferential direction is indicated by way of example in FIG. 6 . Typically, the distance d _C is the distance between the central axes of adjacent gas outlets 175 , as shown in FIG. 6 . Accordingly, typically the distance d _G between adjacent gas supply slits 173 is the distance between the central axes of adjacent gas supply slits 173 . In particular, as exemplarily shown in FIG. 6 , the distance d _G may substantially correspond to the distance d _C , ie d _G =d _C . The term "substantially corresponding" is understood to mean that since the diameter D of the coating drum is much larger than the distance d _G between adjacent gas supply slits in the circumferential direction and the distance d _C between adjacent gas outlets, ie D >> _dC and D>> _dG , so the curvature of the coating cylinder has a negligible effect on the difference between _dG and _dC . Correspondingly, precisely, the included angle between the central axes of adjacent gas outlets 175 may be the same as the included angle between the central axes of adjacent gas supply slits 173 . As exemplarily shown in FIG. 4 , generally the number of gas outlets 175 in the circumferential direction corresponds to the number of gas supply slits 173 . Alternatively, the number of gas outlets in the circumferential direction may be any integer multiple of the number of gas supply slits.

Referring exemplarily to FIG. 5 , according to an embodiment that may be combined with other embodiments described herein, the distance dA between adjacent gas outlets in the axial direction may be selected from a range between a lower limit d _AL and an upper limit d _AU , that is, d _AL ≤d _A ≤d _AU . The lower limit d _AL may be d _AL =4 mm, in particular d _AL =6 mm, more in particular d _AL =8 mm. The upper limit d _AL may be d _AL =10 mm, in particular d _AL =12 mm, more in particular d _AL =15 mm. For example, the distance d _A may be 10mm.

According to an embodiment, which may be combined with other embodiments described herein, the distance dC between adjacent gas outlets in the circumferential direction corresponds to the distance _dA between adjacent gas outlets in the axial direction, ie _dC = d _A . In other words, the plurality of gas outlets described herein may be regularly distributed in the sleeve.

Referring exemplarily to FIG. 7 , according to an embodiment that may be combined with any of the other embodiments described herein, the sleeve 174 includes an insulating top layer 177 and an inner insulating sleeve 174I. As shown in FIG. 7, metal layer 176 may be disposed between isolation top layer 177 and inner isolation sleeve 174I. In particular, metal layer 176 may be disposed under isolation top layer 177 . More specifically, metal layer 176 may be disposed directly under the isolation top layer. Accordingly, metal layer 176 may be in contact with the isolation top layer. Additionally, a metal layer 176 may be disposed on top of the inner spacer sleeve 174I. In particular, metal layer 176 may be disposed directly on top of inner spacer sleeve 174I. Accordingly, metal layer 176 may be in contact with inner spacer sleeve 174I.

As exemplarily shown in FIG. 7 , according to an embodiment, which may be combined with any of the other embodiments described herein, a plurality of gas outlets 175 extend through insulating top layer 177 and inner insulating sleeve 174I. Correspondingly, the inner wall of the gas outlet is provided with an insulating material 1740 , that is, the insulating material of the insulating top layer 177 and the insulating material of the inner insulating sleeve 174I. In other words, the inner wall of the gas outlet can consist of insulating material. It should be appreciated that insulation top layer 177 and inner insulation sleeve 174I are comprised of insulation material 1740 .

With exemplary reference to FIG. 8 , according to an embodiment that may be combined with any of the other embodiments described herein, the sleeve 174 includes an outer insulation layer 178 disposed on an inner metal sleeve 174M. Metal layer 176 is embedded within outer isolation layer 178 . It should be appreciated that outer isolation layer 178 is comprised of isolation material 1740 . As exemplarily shown in FIG. 8, a plurality of gas outlets 175 extend through the outer insulation layer 178 and the inner metal sleeve 174M. Correspondingly, the inner wall of the gas outlet is provided with the insulation material of the outer insulation layer 178 and the material of the inner metal sleeve 174M.

According to an embodiment, which may be combined with any other embodiment described herein, the metal layer 176 is connected to a potential applying device 1720 , as schematically indicated in FIGS. 6 and 7 .

In the present disclosure, a "potential applying device" may be understood as a device configured to apply a potential to a coating drum, in particular to the metal layer of the coating drum. In particular, the potential applying device described herein may be configured to provide a medium frequency (MF) potential. For example, the medium frequency (MF) potential may be from 1 kHz to 100 kHz. Typically, the potential applying device is connected to the coating cylinder via physical contacts, eg electrical contacts. Accordingly, an electrical contact can be provided between the potential applying device and the coating cylinder. For example, the electrical contacts may be electrical sliding contacts or brush contacts. According to another example, the electrical contacts may be plug contacts. Correspondingly, a potential applying device is to be understood as a charging device configured to provide an electrical charge to the coating cylinder, in particular to the metal layer embedded in the insulating material. It should be understood that electrical connection lines to the embedded metal layers are typically provided.

According to an embodiment, which may be combined with any other embodiment described herein, the potential applying device is configured for applying a potential with a medium frequency (MF), in particular a frequency of 1 kHz to 100 kHz. In other words, the potential supplied from the potential applying means may be a potential having a frequency of 1 kHz to 100 kHz. In particular, a medium-frequency potential is to be understood as a potential having alternating polarity at a frequency selected from the range 1 kHz to 100 kHz. It has been found that applying an MF potential to the coating drum has the advantage that charging of the substrate, especially the layer deposited on the substrate, can be substantially avoided or even eliminated. Accordingly, layers with higher quality (eg, higher uniformity, fewer defects, etc.) can be deposited on the substrate.

With exemplary reference to Figure 9, an alternative arrangement is described which addresses the same problems as the embodiment of the coating drum described with reference to Figures 4-7. In particular, the alternative configuration shown in Figure 9 also advantageously provides the possibility of increasing the contact pressure between the coating roller and the flexible substrate by using electrostatic interactions, while avoiding the harmful effects such as leakage or arcing. As shown schematically in FIG. 9 , according to an embodiment, which may be combined with any of the other embodiments described herein, the coating drum 17 may comprise a sleeve 174 having a plurality of inserts 179 of insulating material. Additionally, each insert in plurality of inserts 179 includes a gas outlet 175 . Accordingly, a plurality of gas outlets 175 are provided in a plurality of inserts 179 .

According to an embodiment, which may be combined with any other embodiment described herein, the surface of the gas supply slit 173 may be coated with an insulating material. In other words, the gas supply slit 173 may include a barrier coating 173C, as exemplarily shown in FIG. 9 . Additionally, the sleeve 174 may include an insulating top layer 177 and an inner metal sleeve 174M. The isolation top layer 177 may also cover the outer top surfaces of the plurality of inserts 179 . Furthermore, as schematically indicated in Figure 9, the inner metal sleeve 174M may be connected to a potential application device 1720 as described herein. Alternatively, the potential applying device 1720 may be connected to the main body 171 .

With exemplary reference to Figure 10 showing a schematic top view of the coating drum 17, according to an embodiment which may be combined with any other embodiment described herein, the density of the plurality of gas outlets 175 provided in the sleeve 174 is directed towards the coating At least one of the first axial end 17A and the second axial end 17B of the drum 17 changes. In Fig. 10, the length L of the coating drum, the diameter D of the coating drum and the central axis of rotation 17C of the coating drum are indicated. Generally, the density of the plurality of gas outlets 175 changes towards both axial ends of the coating drum 17 , namely the first axial end 17A and the second axial end 17B. More specifically, the density of the plurality of gas outlets 175 provided in the sleeve 174 may vary symmetrically toward the first axial end 17A and the second axial end 17B of the coating drum 17, particularly with respect to the first axial The axial middle between the end 17A and the second axial end 17B changes symmetrically. In particular, as shown in FIG. 10, the distance d _A between adjacent gas outlets may decrease towards the first axial end 17A and/or the second axial end 17B of the coating drum 17, illustrated in FIG. Indicated by d _A1 <d _A2 <d _A3 <d _A4 , causing the gas outlet density to increase towards the first axial end 17A and/or the second axial end 17B of the coating drum 17 .

In the present disclosure, the expression "density of a plurality of gas outlets" can be understood as the number of gas outlets per unit area. Accordingly, a higher density of gas outlets generally results in a shorter distance between adjacent gas outlets, in particular in the direction of the gas supply slit, than gas outlets provided at a lower density. Usually, the gas supply slits are arranged equally distributed in the circumferential direction. In other words, the distance between adjacent gas supply slits in the circumferential direction may be constant. Correspondingly, the distance between adjacent gas outlets generally provided above the gas supply slits is also equally distributed in the circumferential direction. In other words, the distance between adjacent gas outlets in the circumferential direction may be constant. The distance d _C between adjacent gas outlets 175 in the circumferential direction is indicated by way of example in FIGS. 5 and 6 .

Accordingly, advantageously by varying the density of the plurality of gas outlets, the gas flow rate provided to the flexible substrate per unit area can be varied. In particular, by increasing the density of the plurality of gas outlets, the gas flow rate provided to the flexible substrate per unit area can be increased. Correspondingly, by increasing the gas flow, the gas pressure on the flexible substrate can be increased. Therefore, by selecting the density distribution of multiple gas outlets, the gas flow rate per unit area and the gas pressure on the flexible substrate can be adjusted.

Referring exemplarily to FIG. 11 , according to an embodiment that may be combined with any other embodiment described herein, the plurality of gas outlets 175 includes at least a first subset 175A of gas outlets 175 and a second subset 175B of gas outlets 175 . The first subset 175A of gas outlets 175 has a first density. The second subset 175B of gas outlets 175 has a second density different from the first density. In particular, the second density is higher than the first density. Furthermore, as exemplarily shown in FIG. 11 , a second subset 175B of gas outlets 175 may be provided at one or both axial ends 174E of the sleeve 174 . For example, as exemplarily shown in FIG. 11 , the second distance d _A2 between axially adjacent gas outlets of the second subset 175B may be smaller than axially adjacent gas outlets of the first subset 175A. The first distance d _A1 between the gas outlets.

With exemplary reference to FIG. 12 , according to an embodiment that may be combined with any of the other embodiments described herein, the plurality of gas outlets 175 also includes a third subset 175C of gas outlets 175 . The third subset 175C of gas outlets 175 has a third density different from the first density and the second density. In particular, the third density may be lower than the first and second densities. Generally, a third subset 175C of gas outlets 175 is disposed in an intermediate portion 174MP between axial ends 174E of sleeve 174 . For example, as exemplarily shown in FIG. 12C , the third distance d _A3 between axially adjacent gas outlets of the third subset 175C may be greater than that of the axially adjacent first subset 175A. The first distance d _A1 between the gas outlets of the second subset 175B is larger than the second distance d _A2 between the adjacent gas outlets of the second subgroup 175B in the axial direction. Although not explicitly shown, it should be understood from the exemplary embodiments shown in FIGS. 10-12 that additional subsets of various gas outlet densities may be provided.

Referring exemplarily to FIG. 13 , according to an embodiment which may be combined with any other embodiment described herein, the outlet diameters of the plurality of gas outlets 175 are directed into the first axial end 17A and the second axial end 17B of the coating drum 17 . at least one change in . Typically, the outlet diameters of the plurality of gas outlets 175 vary toward both axial ends of the coating drum 17 , ie, the first axial end 17A and the second axial end 17B. More specifically, the outlet diameters of the plurality of gas outlets 175 provided in the sleeve 174 may change symmetrically toward the first axial end 17A and the second axial end 17B of the coating drum 17, particularly with respect to The axial middle between the axial end 17A and the second axial end 17B changes symmetrically.

Accordingly, advantageously by varying the outlet diameters of the plurality of gas outlets, the gas flow rate provided to the flexible substrate per unit area can be varied. In particular, by increasing the outlet diameters of the plurality of gas outlets, the gas flow rate provided to the flexible substrate per unit area can be increased. Correspondingly, by increasing the gas flow, the gas pressure on the flexible substrate can be increased. Therefore, by selecting the outlet diameter distribution of multiple gas outlets, the gas flow rate per unit area and the gas pressure on the flexible substrate can be adjusted.

According to an embodiment, which may be combined with any other embodiment described herein, the outlet diameter of the plurality of gas outlets 175 increases towards at least one of the first axial end 17A and the second axial end 17B of the coating drum 17 . In particular, the outlet diameters of the plurality of gas outlets 175 may gradually increase toward at least one of the first axial end 17A and the second axial end 17B. Typically, the outlet diameters of the plurality of gas outlets 175 increase toward both axial ends of the coating drum 17 (ie, the first axial end 17A and the second axial end 17B). More specifically, the outlet diameters of the plurality of gas outlets 175 provided in the sleeve 174 may increase symmetrically towards the first axial end 17A and the second axial end 17B of the coating drum 17, particularly with respect to the first The axial middle between the axial end 17A and the second axial end 17B increases symmetrically. Increasing the outlet diameter of the plurality of gas outlets towards the axial end of the coating drum can be beneficial in reducing or even avoiding the pressure drop towards the edge of the substrate. Accordingly, substrate cooling efficiency can be improved. In addition, substrate cooling uniformity can be improved.

Although not explicitly shown, it should be understood that the outlet diameters of the plurality of gas outlets 175 may also decrease towards at least one of the first axial end 17A and the second axial end 17B of the coating drum 17 .

With exemplary reference to FIG. 14 , according to an embodiment that may be combined with any other embodiment described herein, the plurality of gas outlets 175 includes at least a fourth subset 175D of gas outlets 175 and a fifth subset 175E of gas outlets 175 . A fourth subset 175D of gas outlets 175 has a first outlet diameter. A fifth subset 175E of gas outlets 175 has a second outlet diameter different from the first outlet diameter. In particular, the second outlet diameter is larger than the first outlet diameter. Typically, a fifth subset 175E of gas outlets 175 is disposed at one or both axial ends 174E of the sleeve 174 .

Referring exemplarily to FIG. 15 , according to an embodiment that may be combined with any other embodiment described herein, the plurality of gas outlets 175 also includes a sixth subset 175F of gas outlets 175 . A sixth subset 175F of gas outlets 175 has a third outlet diameter different from the first and second outlet diameters. In particular, the third outlet diameter may be smaller than the first outlet diameter of the fourth subset 175D of gas outlets 175 . Additionally, the third outlet diameter may be smaller than the second outlet diameter of the fifth subset 175E of gas outlets 175 . Typically, the sixth subset 175F of gas outlets 175 is disposed midway between the axial ends 174E of the sleeve 174 .

Although not explicitly shown, it should be understood from the exemplary embodiments shown in FIGS. 13-15 that additional subsets of various gas outlet diameters may be provided.

Referring exemplarily to FIG. 16 , according to an embodiment, which may be combined with any other embodiment described herein, the coating drum 17 comprises a first coolant supply 1731 for cooling the first portion 1711 of the coating drum 17 . Additionally, the coating drum 17 includes a second coolant supply 1732 for cooling the second portion 1712 and the third portion 1713 of the coating drum 17 . The first part 1711 is disposed between the second part 1712 and the third part 1713 . In particular, the first portion 1711 is the axially middle portion of the main body 171 of the coating cylinder 17 . Generally, the first portion 1711 is the first cylindrical portion of the cylindrical body 171 of the coating drum 17 . Accordingly, generally the second portion 1712 is the second cylindrical portion of the body 171 and the third portion 1713 is the third cylindrical portion of the body 171 .

Accordingly, embodiments of the coating drum may allow for selective and individual cooling of different parts of the coating drum. Accordingly, the portion of the coating drum that is exposed to higher temperatures (typically the middle portion of the coating drum is exposed to elevated temperatures during material deposition) can be cooled independently of the other parts of the coating drum. Furthermore, the embodiments of the coating roll described herein advantageously provide the possibility to extract heat from the flexible substrate in a uniform manner. Accordingly, the risk of the flexible substrate becoming wrinkled during transport can be reduced or even eliminated. Therefore, the quality of coatings deposited on flexible substrates can be improved. Furthermore, an advantage of providing a coating roll with selectively coolable sections is that the roll shape can be controlled by using thermal material deformation effects such as thermal expansion and contraction. For example, the shape of the rollers, in particular the shape of the substrate support surface, can be varied. In particular, the shape of the roller can be controlled to have a flat substrate support surface, a concave substrate support surface or a convex substrate support surface.

In this disclosure, a "coolant supply" may be understood as a device or system configured to provide coolant. Accordingly, the coolant supply described herein generally includes a coolant and a pipe for delivering the coolant. More specifically, the coolant supply may include a closed loop refrigeration system having a heat sink, pressure reducer, booster, and heat rejector. Typically, the heat sink is provided by ducts positioned at the location to be cooled, eg one or more sections of the coating drum as described herein. In this disclosure, "coolant" is to be understood as a cooling fluid, in particular an incompressible cooling fluid, which makes it possible to provide More particularly cooling temperatures in the range -30°C to +80°C. Furthermore, generally the coolant is non-toxic and does not react with lithium. For example, the coolant can be oil.

In the present disclosure, "part of a coating drum" is to be understood as the part of a coating drum having a substrate support surface. In general, a "part of a coating cylinder" as described herein is to be understood as a cylindrical portion of a cylindrical body as described herein.

Referring exemplarily to FIG. 16 , according to an embodiment that may be combined with any other embodiment described herein, a first coolant supply source 1731 is configured to provide a first coolant at a first temperature T1 . The second coolant supply source 1732 is configured to provide a second coolant at a second temperature T2, which is different from the first temperature T1. In particular, the first temperature T1 is lower than the second temperature T2.

As shown schematically in FIG. 16 , according to an embodiment that may be combined with any other embodiment described herein, the first coolant supply 1731 includes a first heat sink for removing heat from the first portion 1711 of the coating drum 17 . 1761. Typically, the second coolant supply 1732 includes a first heat sink 1762 for removing heat from the second portion 1712 of the coating drum 17 . Furthermore, as exemplarily shown in FIG. 16 , the second coolant supply 1732 includes a third heat sink 1763 for removing heat from the third portion 1713 of the coating drum 17 . For example, a "heat sink" as described herein may be provided by a duct, in particular a duct which is in contact with the part of the roll to be cooled. For example, the pipes of the heat sink may comprise windings provided about the central axis of rotation 17C of the roller. For simplicity of illustration, only the upper part of FIG. 16 shows the coolant supply sources, that is, the first coolant supply source 1731 and the second coolant supply source 1732 . However, it should be understood that generally all of the cylindrical sections (eg first section 1711 , second section 1712 and third section 1713 shown in FIG. 16 ) can be cooled by corresponding coolant supplies as described herein. Correspondingly, the illustration of the upper part of FIG. 16 is also applicable to the lower part of FIG. 16 .

As schematically shown in FIG. 16 , according to an embodiment that may be combined with any other embodiment described herein, the first coolant supply source 1731 includes a first coolant pipe 1741 and the second coolant supply source 1732 includes a second The coolant pipe 1742 , the first coolant pipe 1741 and the second coolant pipe 1742 are all connected to the common coolant outflow pipe 1750 . In particular, as exemplarily shown in FIG. 16 , the coolant outflow duct extends in the direction of the central rotational axis 17C of the roller.

Referring exemplarily to FIG. 17 , according to an embodiment which may be combined with any other embodiment described herein, the roll further comprises a third coolant supply 1733 for cooling the fourth portion 1714 and the fifth portion 1715 of the coating drum 17 . Typically, the second portion 1712 is disposed between the first portion 1711 and the fourth portion 1714 . The third part 1713 may be disposed between the first part 1711 and the fifth part 1715 . Generally, the fourth portion 1714 is the fourth cylindrical portion of the cylindrical body 171 of the coating drum 17 . Accordingly, generally fifth portion 1715 is the fifth cylindrical portion of cylindrical body 171 .

As shown schematically in FIG. 17 , according to an embodiment that may be combined with any other embodiment described herein, the third coolant supply source 1733 includes a fourth suction for removing heat from the fourth portion 1714 of the coating drum 17 . Heater 1764. Furthermore, typically the third coolant supply 1733 includes a fifth heat sink 1765 for removing heat from the fifth portion 1715 of the coating drum 17 . Similarly, as in FIG. 16 , only the lower portion of FIG. 17 shows the third coolant supply source for simplicity of illustration. However, it should be understood that the illustration of the third coolant supply source 1733 shown in the lower portion of FIG. 17 generally also applies to the upper portion of FIG. 17 .

As exemplarily shown in FIG. 17 , according to an embodiment that can be combined with any other embodiment described herein, the third coolant supply source 1733 includes a third coolant pipe 1743 connected to a coolant outflow pipe 1750 through which the coolant flows out The duct 1750 extends in the direction of the central rotation axis 17C of the coating drum 17 . In particular, as exemplarily shown in FIG. 17 , each of the first coolant pipe 1741 , the second coolant pipe 1742 and the third coolant pipe 1743 is connected to a common coolant outflow pipe.

According to an embodiment which may be combined with any other embodiment described herein, the third coolant supply source 1733 is configured to provide a third coolant at a third temperature T3, which is different from the first temperature T1 and the second temperature T3. temperature T2. In particular, the third temperature T3 may be lower than the first temperature T1. Additionally or alternatively, the third temperature T3 may be lower than the second temperature T2.

Referring exemplarily to FIG. 1 , according to an embodiment, which may be combined with any other embodiment described herein, a processing system 100 includes a pre-processing machine 60 for processing a substrate prior to its introduction into the processing chamber 20 . In particular, the pretreatment machine 60 is arranged in the winding chamber 10 and is arranged downstream of the supply roll 11 and upstream of the coating cylinder 17 . According to an embodiment, which may be combined with any other embodiment described herein, the pretreatment machine 60 is a plasma treatment device. Typically, a plasma processing apparatus includes a plasma source connected to a power source for supplying current to the plasma source. The plasma source is configured to generate plasma. A plasma is an ionized gas-phase species that may include ions, electrons, and neutral atoms and/or molecules that generally maintain electrical neutrality. A plasma contains equal amounts of positive and negative charges, except for the boundary region between the plasma and electrons. Furthermore, the charged particles in the plasma collectively respond to an external electromagnetic field.

Accordingly, it should be understood that when a substrate is surface treated with the plasma pretreatment apparatus described herein, energetic particles (such as ions and/or electrons) generated in the plasma interact with the surface of the polymer film (usually via free radicals). chemical process) interact strongly. Overall, four main effects of plasmas on polymer film surfaces are generally observed. Each effect is always present to some degree, but one effect may be favored over the other, depending on the substrate, process gases, plasma processing apparatus, and process parameters.

Accordingly, the four main effects are: (a) surface cleaning, which removes organic contaminants from the substrate surface; (b) ablation or etching of material from the substrate surface, which removes weak boundary layers and increases the surface area; (c) cross-linking or branching of polymeric molecules of the substrate near the surface, which can enhance the cohesion of the substrate surface; and (d) modification of the chemical structure of the substrate surface, which can occur during surface treatment of the substrate with a plasma treatment device and Upon re-exposing the treated portion of the substrate to air, the free radicals remaining upon re-exposing the treated portion of the substrate to air may react with atmospheric oxygen or water vapor.

In addition, electrons and ions in the plasma can disappear by diffusion or recombination during the surface treatment of the polymer film. In order to maintain a stable plasma, an external excitation is required to generate more electrons and ions such that their production and loss rates are balanced. Most methods of plasma generation rely on imparting sufficient energy to electrons to dissociate neutral atoms or molecules into ions and electrons. Some plasma sources applying such plasma generation methods are glow discharge, corona discharge, capacitively coupled discharge, inductively coupled discharge, and electron cyclotron resonance (ECR). It should be understood that the effect of the plasma on the surface of the polymer film can mainly be controlled by changing various process parameters such as plasma source pressure, plasma power supply, process gas type, process gas flow rate, treatment duration (or treatment speed) ) and the distance from the plasma to the substrate surface.

In particular, a plasma treatment device that can be used to improve the adhesion properties of polymeric substrates is a corona treatment device. A corona treatment unit uses a low-temperature corona discharge plasma to change the properties of a surface. For example, corona treatment devices are designed to increase the surface energy of polymeric substrates to allow for improved adhesion of coatings such as inks and adhesives. As a result, the surface-treated substrate exhibits improved printing and adhesion quality and lamination strength. Accordingly, it should be understood that the pre-treatment machine 60 may be a corona treatment device.

Accordingly, providing a pre-treater as described herein may be beneficial in preparing the substrate surface for subsequent coatings to be provided on the substrate surface. In particular, the adhesion properties of substrates for subsequent coatings can be improved by using a pre-treater as described herein.

Referring exemplarily to FIG. 1 , according to an embodiment, which may be combined with any other embodiment described herein, a processing system 100 includes a device for processing a substrate after it has been guided from the processing chamber 20 back into the winding chamber 10 , in particular is a post-processing machine 70 for processing the coating on the substrate. In particular, a finisher 70 is arranged in the winding chamber 10 and is arranged downstream of the coating cylinder 17 and upstream of the tension roller 15 .

According to an embodiment, which may be combined with any of the other embodiments described herein, the post-processor 70 may be configured to subject the coated substrate to an oxidizing atmosphere, particularly at elevated temperature. In the present disclosure, an "oxidizing atmosphere" may be understood as an atmosphere that promotes oxidation reactions, for example to improve the stoichiometry of a layer deposited on a substrate. For example, an oxidizing atmosphere may contain greater than 20 volume percent oxygen. Typically, the post-processor 70 includes a gas supply 71 configured to supply a gas, in particular an oxidizing gas such as oxygen, to the coated substrate. Furthermore, the post-processor 70 may include a suction device 72 configured to suck excess oxidizing gas, ie, oxidizing gas not used to oxidize the layer deposited on the substrate. The suction device 72 may be arranged opposite to the gas supply source 71 with respect to the flexible substrate. Accordingly, the gas supplied by the gas supply source 71 may be supplied to the layer deposited on the substrate, traverse the substrate, and be sucked by the suction device 72 .

Additionally or alternatively, the post-processor 70 may be configured for annealing the coated substrate, in particular for annealing a layer deposited on the substrate. It is to be understood that a "coated substrate" includes a substrate as described herein and a coating of an evaporated material as described herein deposited on the substrate. A coating of deposited material may also be referred to as a layer. The post-processor 70 may include a heater 73 configured to increase the temperature of at least one of: the supplied oxidizing gas, the layer deposited on the substrate, and the substrate.

According to an embodiment, which may be combined with any of the other embodiments described herein, the reprocessing machine 70 includes a plasma source 74 . Generally, the plasma source 74 is configured to generate plasma between the gas supply source 71 and the flexible substrate 1 . For example, plasma source 74 may be an electron beam device configured to ignite a plasma with an electron beam. Alternatively, the plasma source may be a hollow anode plasma source. Plasma source 74 may be employed to ionize and/or heat the oxidizing gas supplied by gas supply 71 , which may be beneficial in increasing the rate of oxidation of layers deposited on the substrate.

With exemplary reference to FIG. 1 , processing system 100 includes layer measurement system 80 , according to an embodiment that may be combined with any of the other embodiments described herein. Typically, the layer measurement system 80 is arranged downstream of the coating cylinder 17 . In particular, layer measurement system 80 is configured for evaluating coating layers disposed on substrates. More specifically, layer measurement system 80 may be configured to measure coating thickness and/or coating uniformity. Typically, layer measurement system 80 includes one or more measurement probes.

For example, one or more measurement probes may include one or more radiation sources and one or more sensors/detectors arranged and configured to measure radiation transmission through the coated substrate. Accordingly, one or more radiation sources may be arranged on the coated side of the substrate (ie the front side of the substrate) and one or more sensors/detectors may be arranged on the opposite side (ie the back side of the substrate). Additionally or alternatively, one or more radiation sources and one or more sensors/detectors may be arranged and configured to measure reflectance from the coated substrate. Accordingly, one or more radiation sources and one or more sensors/detectors may be arranged on the same side of the substrate, which is usually the coated side. For example, the one or more radiation sources may be one or more selected from a light source, a gamma ray source, an X-ray source, and a short wavelength radiation source. Accordingly, one or more sensors/detectors may be arranged and configured for detecting the reflectivity and/or transmission of corresponding radiation of the employed radiation source. It should be understood that the layer measurement system 80 can be configured to take multiple measurements across the width of the substrate so that information about the uniformity of the coating thickness can be obtained. In particular, layer measurement system 80 may include a plurality of measurement probes arranged along a line across the width of the substrate. More specifically, these measurement probes may be arranged at a position relative to the substrate that coincides with the position of the crucible relative to the substrate. Furthermore, one or more measuring probes may be arranged at positions corresponding to the positions between the crucibles, which may be beneficial for the measurement of substrate curvature, in particular for reference.

With exemplary reference to FIG. 1 , according to an embodiment, which may be combined with any other embodiment described herein, a handling system 100 includes a pivot arm 18 disposed in the winding chamber 10 . In particular, the pivot arm 18 is arranged downstream of the tension roller 15 and upstream of the take-up roller 12 . Typically, the pivot arm 18 is movable relative to the take-up roller 12, as indicated by the double-headed arrow in FIG. 1 . The pivot arm 18 may include one or more guide rollers 13 . Furthermore, the pivoting arm may comprise spreading rollers 14 . It will be appreciated that typically one or more guide rollers 13 and/or spreader rollers 14 are rotatably mounted to the pivot arm 18 . The pivot arm 18 advantageously provides the possibility to accommodate the increased roll diameter of the take-up roll due to the rolled up substrate. In particular, advantageously, the distance between the outer diameter of the take-up roller and the last guide roller 13 of the pivoting arm 18 can be kept substantially constant. Furthermore, the gap provided by the distance between the outer diameter of the take-up roll and this last guide roll 13 can be controlled by a light barrier. Accordingly, the movement of the pivoting arm 18 can be automatically controlled, for example to move up or down, depending on the amount of substrate rolled up on the take-up roller 12 .

As exemplarily shown in FIG. 1 , the process chamber 20 accommodates an evaporator 30 arranged below the coating drum 17 . The evaporator is configured for evaporating material to be deposited on the flexible substrate. Accordingly, the material to be deposited is a material that can be evaporated. For example, materials that can be deposited by evaporation include metals (eg, aluminum, copper, silver, tin, etc.), ZN/ZnS, ceramics (eg, _AlOx, etc.), polymers, and other materials suitable for evaporative deposition.

Typically, the evaporator 30 comprises a crucible arrangement 35 having a number R of adjacent rows of crucibles 350 . Typically, the crucible arrangement 35 is arranged inside an evaporator box 31 having a top main opening 311 . 18 and 19 illustrate an exemplary embodiment with two rows of crucibles, a first row of R1 crucibles and a second row of R2 crucibles 350 . In particular, the first row R1 crucibles and the second row R2 crucibles 350 are parallel to each other. Furthermore, as exemplarily shown in FIG. 19, the crucibles of the second row R2 are offset in the length direction of the evaporator relative to the crucibles of the first row R1. More specifically, the centers of the crucibles of the second row R2 are arranged with a first offset O1 in the width direction of the evaporator and a second offset O2 in the length direction of the evaporator, as exemplarily indicated in FIG. 19 .

As exemplarily shown in FIG. 1 , a movable baffle 32 is generally provided between the evaporator 30 and the coating drum 17 . As indicated by the double-headed arrow in the movable baffle 32 shown in FIG. 1 , the movable baffle 32 can be moved in and out of the evaporation path. The evaporation path is the path of evaporated material from the crucible 350 to the flexible substrate guided by the coating drum 17 .

As exemplarily shown in FIG. 18 , the evaporator case 31 may include a side shutter 33 for opening and closing a side opening 312 of the evaporator case 31 . The side opening may include a window. As schematically shown in FIG. 1 , side openings may be used to shine light from a stroboscope 22 into the evaporator box 31 . Thereby, the operator can visually check the evaporation.

According to an embodiment, which may be combined with any other embodiment described herein, the evaporator tank may comprise cooling means. In particular, cooling of the evaporator tank may be provided by cooling ducts in contact with the walls of the evaporator tank. For example, cooling ducts may be provided inside the evaporator tank wall. It will be appreciated that during operation a coolant such as water may be provided into the cooling conduit.

Typically, each of the crucibles 350 is surrounded by a separate induction coil 36 as schematically shown in FIG. 19 . The individual induction coils are individually connected to individual power sources 41 of the power system 40 . Accordingly, the crucible can be heated inductively. In other words, crucible 350 is an induction heated crucible.

With exemplary reference to FIG. 19 , according to an embodiment that may be combined with any other embodiment described herein, the evaporator 30 includes a power source 40 for separately supplying a number N _f of alternating currents of different frequencies f _N to adjacent Induction coil, where N _f =3 or N _f =R+1. It should be understood that the maximum number N _f of different frequencies f _N may correspond to the number of crucibles of the evaporator. In particular, the power supply 40 generally includes a separate power supply 41 connected to a separate induction coil 36 surrounding a separate crucible 350 .

Accordingly, by providing a power supply 40 as described herein for separately supplying a number _Nf of alternating currents of different frequencies _fN to adjacent induction coils, interference such as between induction coils and / or adverse effects such as resonance.

According to an embodiment, which may be combined with any other embodiment described herein, the number N _f of different frequencies f _N have frequencies in the range 5 kHz≦f _N ≦100 kHz. The frequency difference provided to adjacent induction coils is Δf≥2kHz. More specifically, usually the difference Δf in the frequencies supplied to adjacent induction coils is selected from the range 2kHz≤Δf<50kHz, in particular the range 4kHz≤Δf≤25kHz.

According to an embodiment, which may be combined with any other embodiment described herein, a number _Nf of different frequencies f _N are selected to provide two or more frequency differences different from each other. For example, a number _Nf of different frequencies f _N may be chosen to provide a first frequency difference Δf ₁ ≥ ₂ kHz and a second frequency difference Δf ₂ ≥ 2 kHz, the second frequency difference Δf ₂ being different from the first frequency difference Δf ₁ . For example, the first frequency difference Δf ₁ may be selected from the range of 2 kHz ≤ Δf ≤ 50 kHz, especially 4 kHz ≤ Δf ₁ ≤ 25 kHz. Correspondingly, the second frequency difference Δf ₂ can be selected from the range of 2kHz≦Δf ₂ ≦50kHz, especially 4kHz≦Δf ₂ ≦25kHz.

According to an embodiment, which may be combined with any other embodiment described herein, the number N _f of different frequencies f _N comprises a first frequency f ₁ , a second frequency f ₂ and a third frequency f ₃ . The first frequency f ₁ may be selected from the range of 5 kHz ≤ f ₁ ≤ 100 kHz, especially 5 kHz ≤ f ₁ ≤ 50 kHz, more particularly 10 kHz ≤ f ₁ ≤ 20 kHz. The second frequency f ₂ may be selected from the range 5 kHz ≤ f ₂ ≤ 100 kHz, in particular 10 kHz ≤ f ₂ ≤ 50 kHz, more in particular 10 kHz ≤ f ₂ ≤ 30 kHz. The third frequency f ₃ may be selected from the range of 5 kHz ≤ f ₃ ≤ 100 kHz, in particular 15 kHz ≤ f ₂ ≤ 50 kHz, more in particular 20 kHz ≤ f ₂ ≤ 40 kHz. It will be appreciated that the first frequency f ₁ , the second frequency f ₂ and the third frequency f ₃ are chosen to be different from each other. Furthermore, it should be understood that the number _Nf of different frequencies _fN may comprise four or more different frequencies.

According to an embodiment, which may be combined with any other embodiment described herein, at least two of the different frequencies f _N of the number N _f are modulated with respect to at least one of: their amplitude, phase and frequency. In particular, a closed loop control is provided for modulating at least two of the number N _f of different frequencies f _N . At least two of the number N _f of different frequencies f _N may have at least one waveform selected from the group consisting of a sinusoidal waveform, a rectangular waveform or any other periodic waveform. It will be appreciated that, according to some embodiments, which may be combined with any other embodiment described herein, three or more of the different frequencies f _N of the number N _f may be modulated with respect to at least one of: their amplitudes , phase and frequency. In particular, each of the number N _f of different frequencies f _N may be modulated with respect to at least one of: their amplitude, phase and frequency.

providing modulation of at least two of a number N _f of different frequencies f _N with respect to at least one of: their amplitude, phase and frequency, which is beneficial in reducing or even eliminating unwanted resonances between induction coils effects and/or harmful interference effects.

According to an embodiment, which may be combined with any other embodiment described herein, a number N _f of different frequencies f _N is provided by a number N _OC of different oscillating circuits, each oscillating circuit having an inductor and a capacitor. The capacitances C _N of the respective capacitors of the different oscillation circuits are different from each other. In general, a number N _OC of different oscillating circuits corresponds to a provided number N _f of different frequencies f _N (N _OC =N _f ). Accordingly, it will be appreciated that by providing different oscillating circuits which differ in the capacitance of the respective capacitors, different frequencies f _N can be provided to the induction coil surrounding the crucible. Accordingly, the risk of unwanted resonance effects and/or harmful interference effects between the induction coils can be reduced or even eliminated.

According to an embodiment, which may be combined with any other embodiment described herein, the capacitance of the respective capacitor is in the range 1 μF≦C _N ≦50 μF. In particular, the capacitances may be selected to provide a first capacitance difference ΔC ₁ and a second capacitance difference ΔC _{2 ≥ 2} μF of ΔC ₁ ≥ 2 μF. Typically, the second capacitance difference ΔC ₂ is different from the first capacitance difference ΔC ₁ . In particular, the first capacitance difference ΔC ₁ may be selected from the range 2 μF≦ΔC ₁ ≦50 μF, in particular 2 μF≦ΔC ₁ ≦25 μF. Correspondingly, the second capacitance difference ΔC ₂ may be selected from the range 2 μF ≤ ΔC ₂ ≤ 50 μF, in particular 2 μF ≤ ΔC ₂ ≤ 25 μF.

According to an embodiment that can be combined with any other embodiment described herein, the number N _OC of different oscillating circuits includes a first oscillating circuit 411 , a second oscillating circuit 412 and a third oscillating circuit 413 , the first oscillating circuit 411 has ≤ C ₁ ≤ 10μF of the first capacitor C ₁ , the second oscillation circuit 412 has a second capacitor with a second capacitance C ₂ of 3μF ≤ C ₂ ≤ 15μF, the third oscillation circuit 413 has a second capacitor with 10μF A third capacitor with a third capacitance C ₃ ≤ C ₂ ≤ 30 μF. Furthermore, it should be understood that the number N _OC of different oscillating circuits may comprise four or more different oscillating circuits.

According to a specific example, which may be combined with any other embodiment described herein, the evaporator 30 comprises a crucible arrangement 35 having a number R of adjacent rows of crucibles 350 . Each of the crucibles has an induction coil 36 surrounding the individual crucible. In addition, the evaporator 30 includes a power source 40 for respectively supplying a number N _f of alternating currents of different frequencies f _N to adjacent induction coils, where N _f =3 or N _f =R+1. The number N _f of different frequencies f _N includes a first frequency f ₁ , a second frequency f ₂ and a third frequency f ₃ , the first frequency f ₁ is selected from the first range 5 kHz ≤ f ₁ ≤ 20 kHz, the second frequency f ₂ is selected from From the second range 10 kHz ≤ f ₂ ≤ 30 kHz, the third frequency f ₃ is selected from the third range 15 kHz ≤ f ₃ ≤ 50 kHz. In addition, at least one of the following is applied: at least two of the different frequencies f _N of the number N _f of modulations with respect to at least one of the following: their amplitude, phase or frequency; and by N _OC different oscillations The circuits provide a number _Nf of different frequencies _fN , each oscillating circuit having an inductor 415 and a capacitor 414, wherein the capacitances C _N of the respective capacitors of the different oscillating circuits are different from each other.

With exemplary reference to the block diagram in FIG. 21 , a method 200 of operating an evaporator according to an embodiment of the present disclosure is described. According to an embodiment, which may be combined with any other embodiment described herein, the method comprises separately supplying (represented by block 210 in FIG. 21 ) a number N _f of alternating currents of different frequencies f _N to adjacent induction coils , where N _f =3 or N _f =R+1, and where R≧2. For example, a number N _f of alternating currents of different frequency f _N are supplied to adjacent induction coils by a number N _OC of different oscillating circuits, each having an inductor and a capacitor, where the capacitance C _N of the corresponding capacitor of the different oscillating circuits different from each other, as described in this article.

Furthermore, the method may comprise modulating (represented by block 220 in Fig. 21 ) at least two of the number _Nf of different frequencies _fN with respect to at least one of: their amplitude, phase or frequency.

Further aspects of the evaporator are described with exemplary reference to FIG. 22 showing a detailed schematic cross-sectional view of a crucible according to embodiments described herein. According to an embodiment, which may be combined with any other embodiment described herein, the crucible of the crucible arrangement described herein comprises a replaceable tank 353 for receiving material 39 to be evaporated. The replaceable tank 353 may also be referred to as a container and may be made of graphite. Typically, during operation, a replaceable tank 353 containing the material 39 to be evaporated is arranged within the receptacle, which may comprise an inner tank 351 and an outer tank 352 . The receiving part (in particular the inner tank 351 and the outer tank 352) may be made of a ceramic material such as AlO _x .

Furthermore, as exemplarily shown in FIG. 22 , according to an embodiment that may be combined with any other embodiment described herein, a circumferential insulator 355 may be provided in the receiving portion. In other words, the circumferential insulator 355 is provided to surround the replaceable tank 353 when the replaceable tank 353 is placed in the receiving portion. Accordingly, a circumferential insulator 355 may be provided between the replaceable tank 353 and the inner tank 351 of the receiving part. For example, circumferential insulation 355 may be carbon fiber fleece. As exemplarily shown in FIG. 22 , a divided bottom plate 354 may be provided between the bottom of the inner tank 351 and the bottom of the outer tank 352 . Typically, the inner tank 351 includes a receiving portion for receiving the bottom plate 354 . The bottom plate 354 may be made of a ceramic material such as AlO _x .

With exemplary reference to Figure 22, according to an embodiment, which may be combined with any of the other embodiments described herein, an induction coil 36 is provided around the crucible. In particular, an induction coil 36 is provided around the receptacle for the replaceable tank 353 . More particularly, an induction coil 36 may be provided around the outer tank 352 of the receiving portion. The induction coil 36 may be embedded in the induction coil insulation 361 . For example, the induction coil insulation 361 may be made of fiberglass, in particular a tempered fiberglass fabric. Additionally, induction coil 36 may include a coating. In particular, the coating of the induction coil can be made of a material resistant to temperatures up to 250° C. and to voltages up to 1500V. For example, the coating material for the induction coil can be made of epoxy/polyester mixtures, especially thermoplastics.

According to an embodiment, which may be combined with any other embodiment described herein, the crucible 350 is arranged on top of the foot plate 37 , as shown by way of example in FIG. 22 . Typically, a foot plate insulator 371 is provided between the foot plate 37 and the crucible 350 . More specifically, the foot plate insulator 371 may be provided between at least one of the bottom of the outer tank 352 and the bottom of the induction coil insulator 361 and the foot plate 37 . The footboard insulation 371 may be made of fiberglass, especially tempered fiberglass fabric. Furthermore, as exemplarily shown in FIG. 1 , an evaporator tank carrier plate insulation 314 may be provided between the foot plate 37 and the bottom of the evaporator tank. The bottom of the evaporator tank may also be referred to as the evaporator tank carrier plate 313 .

With exemplary reference to Figure 22, according to an embodiment, which may be combined with any of the other embodiments described herein, a protective roof 38 may be provided over the crucible 350 of the evaporator. The top cover 38 is configured to provide protection against debris falling between the crucibles 350 of the evaporator. It should be understood that the protective top cover 38 includes openings so that evaporated material can exit the crucible. The top cover 38 can be made of fiberglass, in particular fiberglass fabric or fleece.

In view of the embodiments of the evaporator described herein, it will be appreciated that an improved evaporator is provided over the prior art. In particular, the thermal evaporator described herein is equipped with a number of induction heated crucibles standing upright. Typically, the crucible is enclosed in a water-cooled enclosure, such as an evaporator box including the cooling device described herein. It should be noted that the number of induction heating crucibles is related to the width of the flexible substrate to be coated. Furthermore, embodiments of the evaporators described herein advantageously provide the possibility to vary and match the evaporation rate of each crucible to a selected coating rate. Typically, during depressurization, the evaporator is heated via a ramp function to melt in the material reservoir in the crucible. After the processing chamber is depressurized to high vacuum, the thermal evaporator is turned on. A power supply, which may be mounted on the console, provides electrical power to heat the individual crucibles, in particular to heat the contents of the crucibles above their melting point for vaporization. As described herein, to avoid overheating during the evaporation process, the evaporator region and components such as the coating window are water cooled and partially covered with insulating material. Furthermore, as exemplarily shown in Fig. 19, the crucibles are usually arranged in two or more offset rows, which is beneficial to achieve high layer thickness uniformity. In other words, the layout of the crucible arrangement described herein ensures a uniform layer thickness distribution. In other words, embodiments of the evaporator described herein beneficially provide increased coating uniformity, faster melt times, and improved evaporation control.

In view of the embodiments described herein, it should be appreciated that an improved processing system 100 for coating flexible substrates is provided compared to the prior art. As exemplarily shown in FIG. 1 , the processing system 100 includes a winding chamber 10 accommodating a supply roll 11 for supplying the flexible substrate 1 . In addition, the processing system 100 includes a take-up roll 12 for storing the processed flexible substrate. In addition, a plurality of guide rollers 13 for guiding the flexible substrate along the substrate transfer path are provided. Furthermore, the processing system 100 comprises a processing chamber 20 accommodating an evaporator 30 for evaporating material to be deposited on the flexible substrate 1 . The evaporator 30 is configured according to any of the embodiments of the evaporator described herein. As shown in FIG. 1 , the processing system 100 includes a coating roller 17 for guiding the flexible substrate 1 through the evaporator 30 . It should be understood that coating drum 17 may be configured according to any of the embodiments of coating drum described herein. Furthermore, the winding chamber 10 may include a winding chamber cold trap 19 . Similarly, processing chamber 20 may include a processing chamber cold trap 21 . Providing one or more cold traps may be beneficial in reducing the humidity inside the respective chamber, which may be beneficial in improving the quality of treatment.

With exemplary reference to FIG. 1 , according to an embodiment, which may be combined with any of the other embodiments described herein, the processing system includes a vacuum system 50 . The vacuum system 50 may be configured to evacuate the winding chamber 10 and the processing chamber. Alternatively, two separate vacuum systems (not explicitly shown) are eg a first vacuum system for evacuating the winding chamber 10 and a second vacuum system for evacuating the process chamber 20 .

The term "vacuum" as used herein is to be understood as a technical vacuum having a vacuum pressure of less than, for example, 10 mbar. Typically, the pressure in the vacuum chambers described herein may be between 10 ⁻⁵ mbar and about 10 ⁻⁸ mbar, more typically between 10 ^{−5 mbar} and 10 ⁻⁷ mbar, even more typically about 10 Between ^-6 mbar and about 10 ^-7 mbar.

According to an embodiment, which may be combined with any other embodiment described herein, the vacuum system 50 is configured to provide a first vacuum with a first vacuum pressure p ₁ in the winding chamber 10 and a vacuum with a first vacuum pressure p 1 in the processing chamber 20 . The second vacuum of the second vacuum pressure p ₂ . Typically, the second vacuum pressure p ₂ is two orders of magnitude lower than the first vacuum pressure p ₁ . For example, the first vacuum pressure p ₁ may be in the range of 10 ⁻² mbar and the second vacuum pressure p ₂ may be in the range of 10 ⁻⁴ mbar.

Typically, the vacuum system 50 includes multiple frequency controlled large roots pumps and multiple high efficiency diffusion pumps. Furthermore, typically the vacuum system 50 is configured to provide individual pump settings for each chamber, for example a first vacuum pressure p ₁ in the winding chamber 10 and a second vacuum pressure p ₂ in the processing chamber 20 .

According to an embodiment, which may be combined with any other embodiment described herein, the winding chamber 10 is separated from the processing chamber 20 by one or more gas-filled seals. One or more inflatable seals may also be referred to as pneumatic seals. For example, the one or more inflatable seals may be inflated at ambient pressure during evacuation of the winding chamber and processing chamber. It will be appreciated that typically one or more gas-filled seals are provided at the interface between the winding chamber and the walls of the processing chamber. In other words, the one or more gas-filled seals are arranged and configured to provide an airtight seal between the winding chamber and the processing chamber.

Although FIG. 1 illustrates a particular implementation of a processing system 100 according to the present disclosure, it should be noted that this application shall cover all combinations of the implementations and component arrangements described herein. Accordingly, according to an embodiment which may be combined with any other embodiment described herein, the processing system 100 comprises one or more of the following components: a supply roll 11 according to any embodiment described herein; a supply roll 11 according to any embodiment described herein; A take-up roll 12 according to any embodiment described herein; a plurality of guide rolls according to any embodiment described herein; one or more stretch rolls 14 according to any embodiment described herein; one or more tension rolls 15 according to any embodiment described herein ; one or more rolls 16 according to any embodiment described herein; a coating cylinder 17 according to any embodiment described herein; a pivot arm 18 according to any embodiment described herein; Coil chamber cold trap 19; Process chamber cold trap 21 according to any embodiment described herein; Scintillation meter 22 according to any embodiment described herein; Evaporator 30 according to any embodiment described herein; A power supply 40 according to any embodiment described herein; a vacuum system 50 according to any embodiment described herein; a preprocessor 60 according to any embodiment described herein; a postprocessor 70 according to any embodiment described herein; layer measurement system 80 of any embodiment; and controller 90 according to any embodiment described herein.

With exemplary reference to FIG. 1 , according to an embodiment, which may be combined with any of the other embodiments described herein, a processing system 100 includes a controller 90 for controlling the components of the processing system 100 described herein. Typically, the controller 90 includes a user interface, such as a control panel and a monitor 91, in particular a touch screen, as schematically shown in FIG. 1 .

In this disclosure, the term "control" as used herein may be broadly understood and may include operations for adapting the thickness of a ceramic layer on a substrate. The term "control" may encompass terms such as measuring, evaluating, adjusting, adapting, equalizing, homogenizing, monitoring, monitoring, comparing, correcting and similar terms.

According to an embodiment, which may be combined with any other embodiment described herein, the controller is configured to control the transport speed of the flexible substrate, in particular via the drive roller described herein. In particular, the controller 90 is configured to control the drive of the supply roll 11 and/or the drive of the coating cylinder 17 and/or the drive of the spreader rolls (in particular the drive of the spreader rolls mounted to the pivot arms 18 described herein). ) and/or drive of the take-up roller 12. In addition, the controller 90 may be configured to control the cooling gas supply source 1710 for the coating drum 17, the potential applying device 1720 for the coating drum 17, and the cooling for the coating drum 17 according to the embodiments described herein. at least one of the agent supply sources 1730.

Additionally, controller 90 may be configured to actuate actuator 161 coupled to roll 16 as described herein. Controller 90 may be configured to control pre-processing engine 60 as described herein. In particular, the power supply of the plasma source connected to the preconditioner may be controlled by the controller 90 . In addition, the controller 90 may be configured to open and close the damper 32 described herein provided between the evaporator 30 and the coating drum 17 . Generally, the controller 90 is configured to control the vaporizer 30, and in particular the power system 40 including the plurality of individual power sources 41 described herein. The controller 90 may be configured to control the post-processing machine 70 described herein, in particular at least one of the gas supply source 71 , the suction device 72 , the heater 73 and the plasma source 74 described herein. Additionally, the controller 90 may be configured to control the layer measurement system 80, particularly one or more measurement probes of the layer measurement system 80 described herein. Controller 90 may be configured to control the cooling of tension roll 15 as described herein. Additionally, controller 90 may be configured to move pivot arm 18 as described herein. Additionally, the controller may be configured to control cooling of at least one of the coil chamber cold trap 19 and the process chamber cold trap 21 . Furthermore, the controller 90 may be configured to control the vacuum system 50 described herein.

In view of the embodiments described herein, it should be understood that methods of coating flexible substrates may be provided. In particular, the method includes using an evaporator 30 according to any of the embodiments described herein. Additionally, the method may include employing the method 200 of operating an evaporator according to any of the embodiments described herein. It should be understood that the method of coating a flexible substrate may be performed using the processing system 100 according to any of the embodiments described herein.

Accordingly, in view of the embodiments described herein, it will be appreciated that improved evaporators, improved treatment systems and thus improved methods are provided over the prior art. In particular, embodiments of the present disclosure beneficially provide the possibility to coat a wide variety of flexible substrates in a wide variety of materials by using an evaporation process. The evaporation process described herein employed is highly economical and versatile. Furthermore, the embodiments described herein advantageously provide the possibility to produce substantially pinhole-free coatings. In addition, it should be noted that the embodiment of the evaporator advantageously offers the possibility of operating at higher temperatures compared to the prior art. Accordingly, embodiments of the evaporator described herein advantageously provide increased coating uniformity, faster melt times, and improved evaporation control.

While the foregoing is directed to embodiments, other and further embodiments may be devised without departing from the essential scope, and the scope is determined by the appended claims.

Claims (20)

1. An evaporator (30), comprising: a crucible arrangement (35) having a number R of adjacent rows of crucibles (350), each of said crucibles having an induction coil (36) surrounding an individual crucible; and A power supply (40), the power supply (40) is used to provide a quantity N _f of alternating currents of different frequencies f _N to adjacent induction coils, wherein N _f =3 or N _f =R+1. 2. The evaporator (30) of claim 1, wherein said number _Nf of different frequencies _fN have frequencies in the range of _{5kHz≤fN≤100kHz} , and wherein all The frequency difference Δf≥2kHz. 3. The evaporator (30) of claim 1, wherein said number _Nf of different frequencies _fN have frequencies in the range of _{5kHz≤fN≤100kHz} and are selected to provide a first of _Δf1≥2kHz A frequency difference Δf ₁ and a second frequency difference Δf ₂ ≥ 2 kHz, the second frequency difference Δf ₂ being different from the first frequency difference Δf ₁ . 4. The evaporator (30) of claim 1, wherein said number _Nf of different frequencies f _N comprises a first frequency f ₁ , a second frequency f ₂ and a third frequency f ₃ , wherein said first Frequency f ₁ is 5 kHz ≤ f ₁ ≤ 20 kHz, wherein said second frequency f ₂ is 10 kHz ≤ f ₂ ≤ 30 kHz, and wherein said third frequency f ₃ is 15 kHz ≤ f ₃ ≤ 50 kHz. 5. The evaporator (30) according to any one of claims 1 to 4, wherein at least two frequencies in the different frequencies _fN of the number _Nf are modulated with respect to at least one of the following items: their amplitude, phase and frequency. 6. The evaporator (30) of claim 5, wherein a closed loop control is provided for modulating said at least two of said number _Nf of different frequencies _fN . 7. The evaporator (30) of claim 6, wherein said at least two frequencies in said number _Nf of different frequencies _fN have at least one waveform selected from the group consisting of: Sine, rectangular, or any other periodic waveform. 8. An evaporator (30) as claimed in any one of claims 1 to 4, wherein said number _N of different frequencies _fN is provided by a number _NOC of different oscillating circuits, each oscillating circuit having an inductor and capacitors, wherein the capacitances C _N of respective capacitors of said different oscillating circuits are different from each other. 9. The evaporator (30) of claim 8, wherein said capacitances of said respective capacitors are in the range 1 μF≦ _CN ≦50 μF and are selected to provide a first capacitance difference ΔC of ΔC ₁ ≧2 μF ₁ and a second capacitance difference ΔC ₂ ≥ 2 μF, the second capacitance difference ΔC ₂ being different from the first capacitance difference ΔC ₁ . 10. The vaporizer (30) according to claim 8, wherein said number N _OC of different oscillating circuits comprises a first oscillating circuit, a second oscillating circuit and a third oscillating circuit, said first oscillating circuit having a 1 μF ≤ C ₁ ≤ 10 μF of the first capacitor of the first capacitance C ₁ , the second oscillating circuit has a second capacitor with a second capacitance C ₂ of 3 μF ≤ C ₂ ≤ 15 μF, the third oscillating circuit has A third capacitor with a third capacitance C ₃ of 10 μF ≤ C ₂ ≤ 30 μF. 11. An evaporator (30) comprising: a crucible arrangement (35) having a number R of adjacent rows of crucibles (350), each of said crucibles having an induction coil (36) surrounding an individual crucible; and A power supply (40), the power supply (40) is used to provide alternating currents of different frequencies f _N of the number N _f to the adjacent induction coils respectively, wherein N _f =3 or N _f =R+1, Wherein said number N _f of different frequencies f _N comprises a first frequency f ₁ , a second frequency f ₂ and a third frequency f ₃ , said first frequency f ₁ is selected from a first range 5 kHz≤f ₁ ≤20 kHz, so The second frequency _f2 is selected from the second range _{10kHz≤f2≤30kHz} , the third frequency _f3 is selected from the third range _{15kHz≤f3≤50kHz} , and where at least one of the following applies: Modulating at least two of said number _Nf of different frequencies _fN with respect to at least one of: their amplitude, phase or frequency; and Said number N _f of different frequencies f _N are provided by N _OC different oscillating circuits each having an inductor and a capacitor, wherein the capacitances C _N of the respective capacitors of said different oscillating circuits are different from each other. 12. The evaporator of claim 11, wherein the induction coil (36) comprises a coating of an epoxy/polyester mixture. 13. Evaporator according to claim 11 or 12, wherein the induction coil (36) is embedded in an induction coil insulation (361 ) of glass fiber material. 14. A method (200) of operating an evaporator having an arrangement of crucibles having a number R of adjacent rows of crucibles, each of said crucibles having an induction heating coils, the method comprising: A number N _f of alternating currents of different frequencies f _N are respectively supplied to adjacent induction coils, where N _f =3 or N _f =R+1, and where R≧2. 15. The method of claim 14, further comprising: modulating at least two of said number _Nf of different frequencies _fN with respect to at least one of: their amplitude, phase or frequency. 16. A method as claimed in claim 14 or 15, wherein the evaporator is an evaporator as claimed in any one of claims 1 to 13. 17. A processing system (100) for coating a flexible substrate (1), comprising: A winding chamber (10) housing supply rolls (11) for supplying the flexible substrate (1), take-up rolls for storing the flexible substrate after processing ( 12) and a plurality of guide rollers (13) for guiding said flexible substrate along a substrate transport path; a processing chamber (20) housing an evaporator (30) for evaporating material to be deposited on said flexible substrate (1); and A coating roller (17) for guiding the flexible substrate (1) through the evaporator (30), the evaporator being as claimed in any one of claims 1 to 13 evaporator described above. 18. The processing system (100) of claim 17, further comprising a vacuum system (50), the vacuum system (50) being configured to provide a first vacuum in the winding chamber (10). pressure _p1 and provide a second vacuum with a second vacuum pressure _p2 in said processing chamber (20), said second vacuum pressure _p2 being two times lower than said first vacuum pressure _p1 order of magnitude. 19. The processing system of claim 17 or 18, further comprising at least one of the following: - stretching rollers (14) for providing a defined tension in the width direction of said flexible substrate (1); - a tension roller (15) for increasing said tension of said flexible substrate (1); - a nip roller (16) configured for pressing the flexible substrate (1) onto the substrate stored on the supply roller (11); - a pivot arm (18) movable relative to said take-up roller (12); - a winding chamber cold trap (19) for reducing the humidity inside the winding chamber (10); - a processing chamber cold trap (21) for reducing the humidity inside the processing chamber (20); - a scintillation instrument (22) for observing evaporated material; - a pre-treatment machine (60) for processing said substrate before introducing said substrate into said processing chamber (20); - A post-processing machine (70) for processing said substrate after it has been guided from said processing chamber (20) back into said winding chamber (10) , in particular treating a coating provided on said substrate; - a layer measurement system (80), said layer measurement system (80) being configured for evaluating a coating layer provided on said substrate; and - A controller (90) for controlling process parameters of the treatment system. 20. A method of coating a flexible substrate, said method comprising using at least one of the following: an evaporator according to any one of claims 1 to 13, an evaporator according to any one of claims 14 to 16 The method of operating an evaporator and the treatment system as claimed in any one of claims 17 to 19.