Coating system for coating a substrate with a material vapor

Abstract

The invention relates to a coating system (1) for coating a surface (2') of a substrate (2) with a material vapor (3) from a starting material (10). The coating system (1) comprises: - A coating chamber (6) with chamber inlet (7) and chamber outlet (8), - a tape unwinding station (4) and a tape winding station (5), - a material evaporation device (9) for generating material vapor (3), - a melting pot (11), - a melt atomizer (16) for atomizing a starting material melt (12) into starting material droplets (18), an evaporation crucible (21), optionally an injector tube (20), a nozzle section (29) with a nozzle outlet (29'). In one variant, a tube (14) is coupled to a connection point (13) of the crucible (11), the tube opening (15) of which is arranged at the height level (H1) and causes atomization in the atomizer outlet (19) at height level (H2). The evaporation crucible has heated chamber walls (25) with induction heating (28). An optional gas inlet (22) generates a gas flow (23) that sets the droplets into a rotary flow around the central axis (Z) in the channel (24) between the chamber wall (25) and the immersion tube (26). The funnel-shaped chamber bottom (30) allows for the removal of impurities. The evaporated material exits through the opening (27) on the immersion tube (26).

Description

[0001] The invention relates to a coating system for coating a substrate with a material vapor.

[0002] For coating substrates, processes based on the principle of vapor deposition (VPD) can be used. The principle of VPD involves using a material vaporization device to bring a starting material into a gas phase and releasing it within a coating chamber. The components of the material, particularly atoms and / or ions, then move within the coating chamber until they collide with a substrate. A substrate, such as a sheet or strip of metallic material, is precisely positioned in the coating chamber and is exposed to the material in the gas phase, resulting in the formation of a coating. VPD processes are particularly suitable for coating strips, especially metallic strips such as steel strips.The belt is transported through the coating zone and past the material evaporation device, with the surface to be coated facing a material outlet of the device, so that the components of the material present in the gas phase settle on the belt to be coated and thereby form a coating.

[0003] One advantage of vapor deposition (VPD) is that it allows for the cost-effective production of coatings whose properties can be precisely controlled to a high degree and within a wide range of parameters. Another advantage is its suitability for producing coatings of many different materials. Unlike some other processes, VPD is particularly well-suited for producing coatings of high-melting-point materials or of materials present in metastable phases within the coating.

[0004] The starting material can be fed into a material evaporation device in fundamentally different ways. Some material evaporation devices evaporate liquefied starting material, for example, via thermal evaporation. Other material evaporation devices require the starting material to be fed in solid form, as is the case, for example, with sputter deposition in the form of solid targets. Providing the starting material in solid form involves increased effort for the production of the solid starting material. Conversely, choosing liquid-based evaporation as an alternative involves potentially more complex handling of the liquefied starting material.

[0005] Against this background, the present invention aims to provide a material evaporation device with improved handling and efficiency in the provision and evaporation of the starting material.

[0006] The problem is solved with a coating system having the features of claim 1.

[0007] A coating system for coating a substrate with a material vapor is proposed.

[0008] The coating system includes a coating chamber. The coating chamber is a closed or largely closed chamber in which a technical vacuum can be maintained, for example between 10 (-5) mbar and 100 mbar, preferably 50 mbar or less.

[0009] For example, in cases where the substrate to be coated is a strip, such as a metallic strip, particularly a steel strip, the coating system can, in a special configuration, include a strip unwinding station and a strip winding station, between which the coating chamber is located. The strip unwinding station serves to take the strip intended for coating from a reel and, by unwinding the reel, to make the strip available for coating. The strip winding station serves to wind up the coated strip. It can then be removed from the winding station as a reel of coated strip.

[0010] The coating chamber is arranged between the unwinding station and the winding station. The coating chamber has an inlet and an outlet, with the strip to be coated flowing from the unwinding station through the inlet into the coating chamber, through the coating chamber, and out of the coating chamber through the outlet, before finally reaching the winding station. The inlet and outlet preferably each have an opening, respectively, that protrudes only slightly beyond the strip cross-section in both the transverse and thickness directions, or that are flush with the strip. Depending on the required vacuum quality, an inlet airlock and / or an outlet airlock may also be optionally provided.For transporting the belt along the described route, a system of appropriately suitable transport rollers is arranged at the coating plant.

[0011] However, other designs of the coating chamber are also conceivable, for example as a closed coating chamber into which substrates are individually inserted, or continuous coating chambers that have a chamber inlet and a chamber outlet, and through which the substrates can be transported with a conveying device, for example with a conveyor belt.

[0012] According to the invention, the coating system includes a material evaporation device. This serves the purpose of converting a starting material into a material that exists in the gas phase.

[0013] Throughout this description, the terms "gas phase" and "evaporation" are used as they are commonly understood in the field of gas-phase deposition technologies. The term "gas phase" implies that a small fraction by weight, for example, up to 30% by weight, preferably no more than 10% by weight, of the material present in the gas phase is not in the gas phase in the strictly physical sense, but instead exists as vapor, aerosol, and / or clusters. The term "evaporation" implies that—depending on the material and technology used—the transition of particles into the gas phase occurs, at least partially, through mechanisms other than evaporation in the strictly physical sense, which denotes a liquid to gas phase transition. Sublimation is one example of such other mechanisms included in this description.The material present in the gas phase in this sense is therefore also referred to synonymously as material vapor within the scope of this application.

[0014] The material evaporation device includes a crucible for melting a starting material. The crucible serves to liquefy a solid starting material, which is then fed to the coating system as a liquid starting material, i.e., as a melt. For this purpose, the solid material—for example, in the form of granules, powder, or pieces—is introduced into the crucible, where it is melted under the influence of heat. The crucible preferably has an electric heating element, but can also be heated inductively or by means of a heat transfer medium. To ensure a uniform temperature distribution and controlled melting behavior, the crucible can be equipped with temperature sensors and a control unit. In a preferred embodiment, the crucible has a heat-insulating casing to reduce heat loss.Optionally, the crucible can also be equipped with a stirrer to ensure a homogeneous distribution of the molten material. For example, the crucible may be a container, such as one made of ceramic, in which the introduced solid material is melted to form the starting material melt. Optionally, the crucible is pressurized with a protective gas to prevent excessive oxidation of the starting material melt. Oxides on the surface of the starting material melt can be removed with a slide gate. The liquefied material, i.e., the starting material melt, can then be transferred from the crucible to the vaporization unit.

[0015] Furthermore, the material evaporation device includes a melt atomizer coupled to the crucible. This atomizer serves the purpose of atomizing the starting material liquefied in the crucible. The melt atomizer is a device suitable for atomizing a melt. It is a technical component with one or more nozzles that disperses liquids or molten metals into fine droplets or particles through pressure and turbulent flow. It consists of a robust housing, connections for the media, and one or more fine outlet openings. Atomizers are known from technical sources. Their suitability for atomizing the melt is determined in particular by the choice of material, which must provide heat resistance to the temperature of the melt intended for atomization.The molten starting material, that is, the material that has been previously liquefied in the crucible, is fed to the atomizer and atomized by it. A pipe leading from the crucible to the atomizer can be used to feed the molten starting material into the atomizer. The pipe is made, for example, of a high-melting-point metallic material or a ceramic. The starting material, having passed through the atomizer as molten starting material, is then present as droplets. These droplets are typically very small, for example, with a diameter between 1 and 100 µm, and in particular a d50 value between 1 and 100 µm, i.e., for example, 10 µm.The melt atomizer consists, for example, of a high-melting-point metallic material, but preferably of a high-temperature-resistant, insulating ceramic material or of a mixture of graphite components and insulating ceramic material, such as boron nitride. Graphitic melt atomizers are also possible.

[0016] The material evaporation device further comprises an evaporation crucible with heated chamber walls, which is coupled to an atomizer outlet of the melt atomizer, so that the starting material droplets emerging from the melt atomizer can be evaporated in the evaporation crucible. The evaporated starting material droplets are then available as material vapor, which can be used for coating the substrate.

[0017] It is possible for the melt atomizer to lead directly into the evaporation crucible. Preferably, however, the material evaporation device has an injector tube. The injector tube is designed to direct the atomized starting material, i.e., the starting material droplets, from the melt atomizer to the evaporation crucible. The injector tube is coupled to the evaporation crucible to guide the atomized starting material into it. The injector tube is preferably made of high-temperature-resistant, insulating ceramic material or of a mixture of graphite components and insulating ceramic material, for example, boron nitride; alternatively, it may be made of graphite or a high-melting-point metallic material, or of combinations thereof.Particularly preferably, the injector tube is actively heated by means of a heating arrangement to ensure that the temperature of the injector tube is sufficiently high to prevent the deposition of starting material droplets. The temperature is at least the melting point of the starting material, preferably the vaporization point of the starting material or higher.

[0018] According to the invention, the evaporation crucible is designed as a cyclone. Within the cyclone, the starting material droplets can be subjected to a rotary flow, thereby increasing the residence time of the droplets within the evaporation crucible. This longer residence time ensures that a higher proportion of the droplets are evaporated, resulting in material vapor containing very few and / or very small droplets, or even no droplets at all. An example of a suitable cyclone can be found in the device known from WO 2016 / 042079 A1. The cyclone thus functions as a cyclone filter, a specific, selectable variant of a centrifugal separator, which is widely used in the prior art and can be engineered to meet specific requirements (e.g., gas flow, starting material, starting material throughput).

[0019] The evaporation crucible can, in principle, be heated in a variety of ways. Inductive heating is advantageous. For this purpose, the crucible can be surrounded by an inductor with a matching impedance, which can advantageously be operated in the range of a few kHz. The maximum voltage of the inductor must be adapted to the vacuum and is preferably set to a value of 250 V or less. The inductor is advantageously completely surrounded by a material that ensures its thermal and electrical insulation. This could be, for example, concrete. The crucible should be surrounded by thermally insulating material to prevent heat loss through thermal radiation. The crucible temperature can be chosen according to one approach so that it exceeds the boiling point of the material to be evaporated. This is, for example, 1200 degrees Celsius for zinc.Alternatively, the temperature can be chosen so that the material to be evaporated already has a noticeable vapor pressure at the prevailing negative pressure (e.g. 2600 degrees Celsius for Fe).

[0020] At the outlet of the evaporation crucible, a nozzle section is provided from which the material vaporized in the cyclone can escape through a nozzle outlet. The nozzle outlet is located within the coating chamber so that when the substrate is positioned facing it or passed by it, the substrate is coated with the material vapor. The nozzle width is preferably adjustable to varying bandwidths. Rotatable nozzles or mechanical adjustments are known for this purpose.

[0021] An apparatus according to the invention, due to the design of the evaporation crucible as a cyclone, has the advantage that the generated starting material droplets are exposed to the heated environment prevailing in the cyclone for a sufficient length of time, due to their rotational movement inevitably induced within the cyclone, to evaporate completely or almost completely. In contrast to previously prevailing approaches and considerations, the apparatus according to the invention, due to the previously unforeseen and unknown coupling of a melt atomizer, leads to the previously unavailable option of generating a material vapor via the intermediate step of producing a starting material melt followed by atomization into fine droplets.The melting of the starting material, which can be implemented without difficulty based on experience in many unrelated fields, is thus combined with the advantageous material vaporization in the cyclone, which, not least, results in a low or even non-existent residual liquid and solid content. The newly provided method of such vapor generation does not require the starting material to be supplied as a solid in a defined form, for example, as a strip or wire. This eliminates the costs associated with the production of such a solid. The apparatus according to the invention thus provides a method for material vapor generation that is comparatively inexpensive, not least in terms of cost.

[0022] If the crucible is open, and the crucible and atomizer are arranged at the same height, then the initial melt is conveyed through the atomizer in the cyclone by the difference between atmospheric pressure and residual gas pressure.

[0023] According to an advantageous embodiment, the crucible is arranged at a first elevation level and the atomizer is positioned at a second elevation level. The first elevation level is above the second elevation level. Due to its elevated position relative to the atomizer, the melt in the crucible possesses potential energy, which, via the supply line (designed particularly as a pipeline), induces or assists atomization in the atomizer, starting from the static pressure. This occurs, for example, in addition to atmospheric pressure when the crucible is open, or in addition to an overpressure set in the crucible relative to atmospheric pressure when the crucible is closed. Furthermore, in the case of the typical technical vacuum prevailing in the coating chamber, the resulting pressure difference is also a factor.This design has the advantage of being relatively simple in terms of equipment, as it utilizes the hydrostatic and hydrodynamic initial conditions of the molten starting material. The precise setting of the required height difference is the responsibility of the implementing specialist, as it depends on the starting material used and the overall prevailing conditions of the coating system, for example, its hydrodynamic properties. This setting is easily achievable for the specialist, since the height difference, being the only selectable parameter, can be readily determined empirically with a manageable number of trials.

[0024] Alternatively or additionally, the crucible can be operated at a melting pressure higher than atmospheric pressure. In particular, it can also be provided that static pressure due to the previously described difference in altitude and an increased melting pressure, for example by means of pumping devices, are used in a complementary manner. If a combination of both is provided, this can be easily implemented by the expert through design, since the methods for generating pressure can generally be considered interchangeable, so that the total required pressure can be distributed among several different methods by the expert, depending on the prevailing requirements and conditions.The method using increased pressure in the crucible is more complex in terms of equipment than the previously described use of hydrostatic and hydrodynamic conditions. However, it offers the advantage of greater flexibility due to the easier adjustment of the melting pressure, for example, by adjusting a pump. This allows it to be adapted to materials of different densities. Furthermore, a height difference is not strictly necessary, or at least only to a lesser extent, thus reducing the required installation space.

[0025] Alternatively or additionally, the material evaporation device can be provided with an interchangeable crucible for alternating operation with the main crucible. With two crucibles, one can, for example, be used to generate the initial material melt while the interchangeable crucible is simultaneously filled with a supply material. During this time, the interchangeable crucible can be decoupled from the atomizer via a shut-off device. Once the melt in the crucible has been fed to the atomizer, the crucible can be decoupled and the interchangeable crucible connected, allowing the supply of initial material melt to the atomizer to continue.Such a design is particularly advantageous when one or both of the crucibles are operated additionally or exclusively with a melting pressure higher than atmospheric pressure, since in such a case a continuous supply of starting material in solid form is not possible or only possible with great effort.

[0026] According to an advantageous further development, the melt atomizer is designed as a pressure nozzle, in particular as a single-component atomizer.

[0027] In a pressure nozzle or single-component atomizer, droplet formation occurs solely through the pressure or kinetic energy of the liquid melt itself. The initial liquid melt is forced through a nozzle or multiple nozzles with a suitable geometry, where the liquid disperses into fine droplets upon exiting. Atomization can be enhanced by appropriate nozzle contour design, such as the use of swirl chambers or convergent nozzle outlets. Single-component atomizers are particularly suitable when the melt possesses sufficient inherent energy to generate a fine atomization without the need for additional media.

[0028] Therefore, designing the melt atomizer as a pressure nozzle and single-component atomizer, especially in combination with the crucible's positioning at a higher potential level in the gravitational field compared to a standard melt atomizer, can offer significant advantages. The choice of a single-component atomizer has the particular advantage that an additional second material, usually a gas, is not required, meaning the choice of the starting material is not limited by the heating capacity of the second material. Potential cooling of the starting material with droplet enlargement or even solidification does not need to be considered, which is why choosing an atomizer designed as a pressure nozzle and single-component atomizer is particularly advantageous for high-melting-point starting materials.

[0029] According to an alternative embodiment, the melt atomizer is designed as a two-component nozzle. In a two-component atomizer, a second substance, typically a gas (e.g., air, nitrogen, or an inert gas), is introduced in addition to the melt. The melt exits the nozzle together with the atomizing gas or is carried along by the gas stream at a suitable point, thereby breaking the liquid into fine droplets. This type of atomization is particularly suitable for more viscous melts or for applications where a particularly fine or directional droplet distribution is desired. The droplet size can be precisely controlled by varying the gas pressure, flow rate, and nozzle arrangement. The two-component atomizer can be designed coaxially, annularly, or with other geometries to optimize the gas-melt mixing process. The second substance is preferably N₂ or Ar.For the second substance, a feed into the two-substance atomizer is provided, which has a heating device for heating the second substance, wherein the heating is preferably carried out to a melting temperature of the starting material, preferably to an evaporation temperature of the starting material.

[0030] In principle, the specific choice of melt atomizer design and the setting of the prevailing pressures depend on the given conditions, not least on the choice of the starting material and the size of the cyclone; given knowledge of the given conditions, the implementation is a matter of interpreting the aforementioned parameters and other design questions, which do not present the expert with insurmountable obstacles in the design process.

[0031] Further details, features and advantages of the subject matter of the invention will become apparent from the following description in conjunction with the drawings, which illustrate exemplary embodiments of the invention.

[0032] It goes without saying that the features mentioned above and explained below can be used not only in the combination specified, but also in other combinations or on their own. Fig. 1: Schematic diagram of a coating system with material evaporation device and single-material atomizer; Fig. 2: Schematic diagram of a further embodiment of a coating system with material evaporation device with single-material atomizer; Fig. 3: Schematic diagram of a coating system with material evaporation device and two-component atomizer.

[0033] Fig. Figure 1 shows an embodiment of a coating system 1 with which a substrate 2, designed as a strip, can be coated with a material vapor 3. The coating system 1 comprises a strip unwinding station 4 and a strip winding station 5. A coating chamber 6 is arranged between the strip unwinding station 4 and the strip winding station 5. The strip unwinding station 4 receives a coil of strip. Such a coil is typically referred to as a coil when the strip is made of steel. The strip, which is the substrate 2 to be coated, is unwound from the coil and guided through the coating chamber 6 for coating, after which the strip is wound up by the strip winding station 5. The coil of coated strip can then be removed from the strip winding station 5 and transferred to further processing or transport.

[0034] The coating chamber 6, located between the unwinding station 4 and the winding station 5, has, in the illustrated embodiment, a chamber inlet 7 and a chamber outlet 8. The strip to be coated is guided from the unwinding station 4 through the chamber inlet 7 into the coating chamber 6, through the coating chamber 6, and out of the coating chamber 6 through the chamber outlet 8, and then fed to the winding station 5. A system of suitable transport rollers is arranged on the coating system for transporting the strip along the described path; these rollers are not shown in the illustration.

[0035] The coating system 1 includes a material evaporation device 9. This device is designed to provide a material 3 in the gas phase by converting a starting material 10 into the gas phase. The gas-phase material 3 produced from the starting material 10 can then deposit on the surface of the substrate 2 and form the desired coating.

[0036] To produce the gaseous material 3, the starting material 10, for example as lump material, is first introduced into a crucible 11. In the crucible, the starting material 10 is heated so that it transitions into a molten material 12. A pipe 14 is connected to a connection point 13, the pipe opening 15 of which serves as a molten outlet at a low-level position in the crucible 11, for example, in the bottom of the crucible 12. The pipe 14 leads to a molten atomizer 16, which is thus connected to the crucible 11. The crucible 11 is located at a first level H1, which is the highest level of the pipe opening 15. The molten atomizer 16 is positioned at a second level H2, which is the highest level of an inlet opening 17 of the molten atomizer 16.The first height level H1 is located at or above the second height level H2. In the first case, the molten starting material 12 exerts a force on the atomizer 16 primarily due to the difference between atmospheric pressure and the technical vacuum prevailing in the coating chamber, as well as the fill level of the crucible 11. In the second case, a hydrostatic pressure component is added due to the height difference H1-H2. This ensures that the molten starting material 12 present in the crucible 11 exerts a force on the atomizer 16, which, if sufficiently high (as determined by appropriate design), produces the desired atomization. The atomizer 16 is designed as a pressure nozzle and, due to the force exerted, atomizes the molten starting material 12 into fine droplets 18, which emerge from an atomizer outlet 19 of the atomizer 16.

[0037] In the embodiment shown, the hydrostatic and hydrodynamic design of the starting material melt 12 is such that an additional supply of a gas is not required, so that the melt atomizer 16 is designed as a single-material nozzle.

[0038] An injector tube 20 is coupled to the atomizer outlet 19 of the melt atomizer 16. The injector tube 20 directs the starting material droplets 18 to and into an evaporation crucible 21. The evaporation crucible 21 is designed as a cyclone and serves to evaporate the fine starting material droplets 18 into the material vapor 3. To ensure the rotational movement of the starting material droplets 18 within the cyclone and to maintain this movement near the inner walls for as long as possible, the injector tube 20 is preferably oriented with a tangential component relative to the central axis Z of the cyclone, pointing into the cyclone.

[0039] An optional gas inlet 22 optionally supplies a gas stream 23 of a gas or gas mixture, preferably heated to a temperature of at least 600 °C and containing no oxygen, preferably Ar or N2 or a mixture of Ar and N2, with a volume flow sufficient to move the gas-vapor droplet mixture of the starting material droplets 18 and the supplied gas in a rotary flow in at least one channel 24 between the chamber wall 25 and a dip tube 26. This causes the existing starting material droplets 18 to be deposited on the heated chamber wall 25, where they are vaporized, and a gas-vapor stream is conveyed to an opening 27 located in the region of the dip tube 26.

[0040] The channel(s) 24 is / are designed such that the path from the atomizer outlet 19 of the melt atomizer 16 to the opening 27 is extended, and the starting material droplets 18 remain on the heated wall due to a rotary flow, thus extending the contact time of the vaporized and / or the material to be vaporized with the heated wall and the residence time in the chamber 24. Since the chamber wall 25 is heated by an induction heater 28 surrounding the vaporization crucible 21 from the outside to above the vaporization temperature of the starting material 10 with which the coating is to be formed, at the pressure maintained in the chamber 24, the material 10 used for coating is completely vaporized, so that it only exits the opening 27 after vaporization and impacts the surface 2' of the substrate 2 to be coated.This allows, in particular, the complete or at least largely avoidance of coating the wall of cyclone 21 and ensures at least near-complete utilization of the material used for coating formation. Complete evaporation also prevents the formation of droplets that would otherwise become embedded in the coating and degrade the surface quality. A funnel-shaped design of the chamber floor 30 can even completely prevent the release of melt droplets if the cyclone 21 is heated slightly below its evaporation temperature.

[0041] The funnel-shaped design of the bottom can also be used to periodically remove the unavoidable high-melting-point impurities of metals and oxides of the starting material 10 from the material evaporation device 9, thus ensuring a stable process over a longer period of time.

[0042] On the outlet side, a nozzle section 29 is coupled to the evaporation pot 21, which connects to the opening 27 and is arranged within the coating chamber 6 with at least one nozzle outlet 29'. The material vapor 3 emerges from the nozzle outlet 29', so that it can condense on the surface 2' of the substrate 2 to be coated, which is oriented towards the opening of the nozzle outlet 29' and is guided past it, thereby forming a coating.

[0043] Fig. Figure 2 shows a different version of a coating system 1. Compared to the one in Fig. In the embodiment shown in Figure 1, the melting crucible 11 is closed. A gas, preferably an oxygen-free gas or a gas containing only a small amount of oxygen, and particularly preferably an inert gas or an inert gas mixture such as Ar or N₂ or an Ar / N₂ mixture, is fed into the crucible via a pipe 32 by means of a pump 33. This allows the crucible to be operated at a melting pressure higher than atmospheric pressure. The pressure exerted on the melt atomizer 16 therefore does not need to be generated, or not solely generated, by the hydrostatic or hydrostatic and hydrodynamic design, but can be generated, or partially generated, by the gas pressure. The melting crucible is refilled via the closable flap 31. To avoid waiting time during refilling, the material evaporation device 9 has an interchangeable melting crucible 11' which can be operated alternately with the melting crucible 11.The interchangeable crucible 11' is filled with feed material 10' via the flap 31', which then transitions into a feed material melt 12'. The pressure required for atomization can be generated via the pipeline 32' and the pump 33'. Differences in height between the crucible 11 and the interchangeable crucible 11' can be compensated for by the pressure generated by pump 33 on the one hand and pump 33' on the other. The crucible 11, 11' that is not in use at a given time can then be filled while the coating system 1 is running. Optionally, the crucible 11, 11' that is not in use at a given time can be temporarily shut off during the period of non-use by a shut-off device 36, 37 in the pipeline 14, 14' leading to the melt atomizer 16.

[0044] Coating plant 1 of the Fig. 3 differs from the system according to Fig. 1 in particular by the fact that the melt atomizer 16 is a two-fluid nozzle. An atomizing gas is passed through a gas supply 34, forming a stream 35. The atomizing gas is preferably an inert gas or an inert gas mixture, for example Ar or N2 or an Ar / N2 mixture. The gas assists the atomization and thus forms the gas stream 23 with which the starting material droplets 18 are guided through the evaporation crucible 9. For this reason, the system of Fig. 3 den in Fig. The gas inlet 22 shown in 1 is not mandatory. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2016 / 042079 A1

[0018]

Claims

[1] Coating system (1) for coating a substrate (2) with a material vapor (3), wherein the coating system (1) comprises: - One coating chamber (6); - a material evaporation device (9) for generating material vapor (3) from material present in gas phase from a starting material (10, 10'), exhibiting a crucible (11, 11') for melting the starting material (10, 10') to a starting material melt (12, 12'), a melt atomizer (16) coupled to the crucible (11, 11') for atomizing the initial material melt (12, 12') into initial material droplets (18), an evaporation crucible (21) designed as a cyclone for evaporating the starting material droplets (18) to the material vapor (3), optionally an injector tube (20), wherein the injector tube (20) is designed to conduct the starting material droplets (18) towards the evaporation crucible (21) and is coupled to the evaporation crucible (21) for guiding the starting material droplets (18) into the evaporation crucible (21), a nozzle section (29) coupled on the outlet side to the evaporation crucible (21) and opening into the coating chamber (6) at least with a nozzle outlet (29'). [2] Coating system (1) according to claim 1, characterized by , that the crucible (11) is arranged at a first height level (H1) and the melt atomizer (16) is positioned at a second height level (H2), wherein the first height level (H1) is at or above the second height level (H2). [3] Coating system (1) according to one of the preceding claims, characterized by, that the crucible (11, 11') can be operated at a melting pressure increased compared to atmospheric pressure. [4] Coating system (1) according to one of the preceding claims, characterized by , that the material evaporation device (9) has an interchangeable crucible (11') for operation alternating with the crucible (11). [5] Coating system (1) according to any one of the preceding claims, characterized by , that the melt atomizer (16) is a pressure nozzle. [6] Coating system (1) according to any one of claims 1 to 4, characterized by , that the melt atomizer (16) is a two-fluid atomizer.

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