DE102011084996A1 - Arrangement for coating a substrate - Google Patents

Abstract

The present invention relates to an arrangement for coating a substrate (12) with an organic coating material (16) comprising at least one evaporation container (18) for receiving organic coating material (16) and at least one heat source (20) for evaporating the organic coating material (16 wherein the evaporation container (18) has a vaporized organic coating material outlet opening (22), and at least one absorption spectroscopic arrangement (26) having a radiation source (32) and a detector (36) for detecting the vapor density of the evaporated coating material (16), and wherein the arrangement further comprises an amplification unit connected to the absorption spectroscopic device (26), which comprises a radiation chopper (37) for generating a time-periodic pulse train of radiation pulses through the radiation source and a lock-in amplifier (38). umfass t. With such an arrangement, the coating rate of about a physical vapor deposition is particularly low maintenance and can be accurately determined. The present invention further relates to a method for coating a substrate (12) with an organic coating material (16).

Description

The present invention relates to an arrangement for coating a substrate, preferably by means of physical vapor deposition, with an improved ascertainability of the coating rate.

State of the art

Various techniques, such as Physical Vapor Deposition (PVD), Chemical Vapor Deposition (CVD) or Molecular Beam Epitaxy (MBE) are known and commonly used to fabricate single or multiple layers of material on a carrier substrate. Physical vapor deposition, for example, is a process in which the starting material or coating material, such as a metal, semiconductor or even organic or inorganic molecules, for example by an electric heater, is heated to temperatures near the boiling point , Moving a material vapor to a substrate and there condenses into a layer. In order to be able to adjust the layer thickness of the deposited material on the substrate, it is particularly necessary to know the coating rate or the material flow from the evaporator to the substrate. Since the material flow or the coating rate is dependent inter alia on factors such as the fill level of the evaporator, the material properties of the contents and the evaporator temperature, this is preferably measured and regulated for a continuous coating process.

For example, to determine coating rates in the coating of metallic coating material, the use of thermocouples (TC), quartz crystal microbalances (QCM), quadrupole mass spectroscopy (QMS), infrared monitoring (Infrared Monitor), light scattering (SLS), spectroscopic ellipsometry (SE), electron impact emission spectroscopy (EIES), atomic spectroscopy (AA) or X-ray fluorescence spectroscopy (RFS, XRF). The described methods are primarily used in a production process of CIGS solar cells and regulate punctiform sputtering sources using metallic coating material. However, such processes are basically not transferable to coating processes for organic coating material.

Therefore, in the case of coating substrates with organic coating material, such as in the production of organic solar cells, the vapor deposition rates are currently measured with quartz crystals or quartz crystal microbalances (QCM) and controlled manually by the heating power at the evaporator.

From the document DE 10 2008 043 634 A1 For example, an evaporator for evaporating organic materials and a coating system, in particular for producing organic light-emitting diodes and / or organic solar cells, are known. The evaporator comprises an evaporation tank having at least one heat source for vaporizing organic material and an outlet for vaporized organic material. In this case, the heat source is arranged outside the evaporation container, the evaporation container from the outside, heated only by heat radiation radiator. The outlet opening is also elongate and linear.

The document DE 10 2009 029 236 A1 also describes an evaporator for vaporizing organic materials and a coating system, in particular for the production of organic light-emitting diodes and / or organic solar cells. In order to realize a rapid adjustment or change in the coating rate, a means for varying the free cross section of a slot-shaped outlet opening of the evaporation container or of an outlet channel downstream of the outlet opening is provided according to this document.

Disclosure of the invention

The present invention is an arrangement for coating a substrate with an organic coating material, comprising at least one evaporation vessel for receiving organic coating material and at least one heat source for vaporizing the organic coating material, wherein the evaporation vessel has an outlet opening for vaporized organic coating material, and wherein at least one Absorption spectroscopic arrangement is provided with a radiation source and a detector for detecting the vapor density of the evaporated coating material, and wherein the arrangement further comprises an associated with the absorption spectroscopic device gain unit, which is a Strahlungszerhacker for generating a time-periodic pulse train of radiation pulses through the radiation source and a lock in amplifier includes.

An arrangement for coating a substrate with an organic coating material may, for the purposes of the present invention, be any arrangement by means of which an organic coating material can be applied to a substrate. Under a coating can therefore in the sense of The present invention is understood to mean any process in which an organic coating material can be applied to a substrate, in particular in the form of at least one layer or coating. The coating can have any suitable shape, structure or thickness and can also be applied in any desired pattern. Preferably, the arrangement for coating a substrate may be or include a physical vapor deposition apparatus. However, within the scope of the present invention, it is not excluded that the device for coating a substrate comprises or is a device for chemical vapor deposition or any other device by means of which an organic material, in particular using a gas phase in a vacuum on a substrate can be applied , Such a device can be used in particular for the production of organic light-emitting diodes (OLEDs) or organic solar cells.

It can be used for example for the deposition of active organic layers and transport layers in vacuum predominantly thermal evaporator. For coating a substrate with organic materials, they can be evaporated in vacuo, depending on the starting material used, in particular in a temperature range between approximately ≥ 100 ° C. and approximately ≦ 700 ° C. With regard to the at least one heat source, particularly good results with regard to the heating rate and the controllability of the temperature of the evaporation vessel or of the organic material to be vaporized can be achieved by using at least one quartz heater, in particular at least one double tube quartz heater.

As organic coating material, which is to be coated in particular by the arrangement according to the invention on a substrate, in particular bathocuproine (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), fullerenes, such as C ₆₀ - or C can serve ₇₀ fullerenes, phthalocyanines such as copper (Cu) or zinc (Zn) phthalocyanine.

The substrate may comprise or be any suitable substrate which is coatable by a method as described above. By way of example, the substrate may be a substrate suitable for producing in particular organic light-emitting diodes, solar cells or other electronic components. By way of example, mention may be made in particular of glass, coated glass, plastics, such as polycarbonate, polyethylene, polycarbonate, polyvinyl chloride, for example in conjunction with a conductive layer and / or as a film.

Furthermore, in the context of the present invention, an evaporation container may in particular be any container in which the organic coating material with which the substrate is to be coated can be initially introduced or at least temporarily taken up.

Furthermore, an amplification unit is provided which comprises a radiation chopper for generating a temporally periodic pulse train of radiation pulses through the radiation source. The Strahlunsgzerhacker can also be called a chopper. Through this a defined sequence of temporally limited radiation pulses becomes possible.

The radiation chopper can be designed, for example, to modulate the radiation emitted by the radiation source into a temporal periodic pulse sequence. Furthermore, the radiation chopper can be connected directly to the radiation source in such a way that the radiation source as such emits a defined radiation pulse sequence. For example, radiation pulses can be generated in a frequency of ≥ 50 Hz to ≤ 100 Hz, this range being not restrictive.

In order to be able to evaluate the signal modulated or generated by the radiation chopper in a particularly advantageous manner, the amplification unit further comprises a lock-in amplifier, which can be suitably connected to the radiation chopper. For the purposes of the present invention, a lock-in amplifier can be understood in particular to be an amplifier which is also referred to as a phase-sensitive rectifier or carrier frequency amplifier and which can represent a narrow-band bypass filter and, in particular, can improve the signal-to-noise ratio of a weak, in particular alternating signal. In particular, the lock-in amplifier can be a phase amplifier which only evaluates and amplifies the radiation pulses. In this case, only the signal-comprehensive phase can be amplified in a particularly advantageous manner, which allows a particularly good improvement of the signal-to-smoke ratio.

In particular, by providing the above-described amplification unit, it may be possible according to the invention to be able to use an absorption spectroscopic device for measuring the vapor rate and thus the rate of coating of organic coating material. Such an amplification unit can be connected to the absorption spectroscopic device, in particular to its detector. This means, in particular, that they represent a separate component or can be integrated into it as part of the absorption spectroscopic device.

Thus, it is possible by the arrangement according to the invention to be able to detect the vapor density in a coating process with an organic coating material accurately and efficiently by an absorption spectroscopic device and thus to be able to control or regulate a coating process efficiently. In principle, this is not possible according to the prior art since, for example, the absorption cross section of organic coating material is lower by a few orders of magnitude, such as by a factor of ten thousand, than in the case of metallic coating processes.

In detail, in absorption spectroscopy, the direct measurement of vapor density in a coating process is based on light absorption and is basically described by the Lambert-Beer law: I = I ₀ exp (-kd). K describes the absorption coefficient, d the optical path length, I ₀ the incident light intensity and I the measured light intensity. In this case, the wavelength-dependent absorption coefficient is determined with the aid of an external light source, which is directly proportional to the vapor density. As light sources both coherent and incoherent light sources can be used. As examples, halogen lamps, such as xenon lamps, may be mentioned here, whereas spectrometers, for example, may be suitable as detectors.

By providing an absorption spectroscopic device for detecting the vapor density, it becomes possible to determine the coating rate of an organic coating material completely or at least partially by optical means. In the context of the present invention, a coating rate may correspond in particular to the amount of coating material which is deposited on the substrate in a specific period of time or with which the substrate is coated. For example, the coating rate may include or correspond to a vapor deposition rate.

Thus, in the arrangement according to the invention, any elements of the absorption spectroscopic device, such as radiation sources or detectors, can be positioned outside the coating cone. As a result, it can be prevented that the absorption spectroscopic device is likewise coated by the coating material or that it is deposited on the device, in particular a radiation source or a detector. This brings a variety of benefits.

On the one hand, the service life or the error-free working intervals and thus the maintenance intervals can be significantly extended. Furthermore, it is not necessary according to the invention to provide change devices or revolvers, as is customary in the case of massecuite crystals. As a result, the required space can be minimized. Furthermore, the fact that the substrate to be coated is not partially covered by the absorption spectroscopic device, the yield of coated as desired substrate can be increased.

In addition, by an inventively possible positioning of the absorption spectroscopic arrangement, in particular completely outside a housing or a coating chamber and also outside the coating cone, for example, the disadvantage of quartz crystal microbalance can be avoided, after which these are coated for working reasons, the partially porous deposited on the quartz crystal microbalance Coating material flakes off again and adversely affects the coating process by introducing particles into the deposited layer. As a result, in a secondment according to the invention, the morphology of the deposited layer can always be formed as desired.

Furthermore, an absorption spectroscopic device offers the advantage of a dynamic and rapid determination of the coating rate, so that any changes can be reacted immediately. Thus, in particular when determining the vapor density, it is possible to react directly to a changing coating rate even during the coating process, so that any errors occurring can be corrected directly. As a result, the rejects during a coating process can be further minimized in the event of errors. In this case, the evaporator rate or the coating rate can be determined using only very short integration times in a range of a few seconds or approximately <1 second. As a result, a fast rate control can be ensured.

Furthermore, absorption spectroscopic devices or the methods that can be carried out thereby for determining the coating rate are usually substantially independent of disturbance variables, such as temperature. As a result, constant or correct rates can be determined even under changing conditions, such as when the temperature changes during the coating by radiant heat of the evaporator, whereby the layer thickness can be set as desired on the substrate or the material composition in the coating as desired can be trained. Further are Absorptionssroskoproskopische devices except for any radiation sources or sources of illumination substantially free of wear.

According to the invention, therefore, a combination of different measurement methods in combination with an in-situ simulation can continue to be realized, with a particularly combined control concept or control concept particularly advantageous for mass production high-rate evaporator sources can be operated in sufficient precision and continuity.

By means of an arrangement according to the invention, it can be possible, in particular, to produce precisely deposited organic coatings on the substrate, which may also have at least two different materials. For example, two different materials may be sequentially applied to the substrate. Furthermore, it becomes possible to deposit mixed layers on the substrate, which have a mixture of at least two different materials. This embodiment may be advantageous, especially in organic photovoltaics, since mixed layers with a defined ratio of a plurality of materials may be desired here. For this it is expedient if the materials can be simultaneously evaporated from different sources through the evaporator sources.

In particular, the density of the atomic / molecular beam produced by each individual evaporator can be determined by absorption spectroscopy. In particular, in the arrangement of a plurality of evaporation tanks or evaporators, the vapor density before each evaporation tank or the respective outlet opening can be determined, in particular a plurality of absorptionssroskoproskopischen devices may be provided so that the coating rate of each evaporator is individually and independently determined. As a result, not only the cumulative evaporation rate or coating rate can be determined in the same substrate position during coating by two or more evaporation sources, but also the mixing ratio can be adjusted as desired and constantly. The use of an absorption spectroscopic device is particularly advantageous for high-rate methods, ie those with high coating rates.

Within the scope of an embodiment, the arrangement may further comprise a reflectometric device and / or a transmission device for determining the layer thickness of an organic coating applied to the substrate. Such devices may be particularly advantageous for thick coatings applied, such as for layer thicknesses from approximately and purely by way of example 40 nm. Such layer thicknesses can be achieved in particular by high-rate processes, ie by those with high coating rates. In this case, a reflectometric device as well as a transmission device in particular comprises a radiation source and a detector. The radiation source may be in particular a halogen lamp such as a xenon lamp or include this and further emit radiation in a wavelength range of about ≥ 300 nm to ≤ 2.5 microns. The radiation can thus be approximately in the range of UV-IR light. In this case, in particular light with all the aforementioned wavelengths is emitted, since a measurement can be so accurate. The detector may in particular be a CCD chip or a suitable spectrometer or comprise such a component.

In detail, the layer thickness of the coating applied to the substrate can be determined by the reflectometric device or also by a transmission device after a coating process or a partial coating process.

In a reflectometric arrangement, light can be radiated from the radiation source onto the coated substrate, expediently onto the coating or else onto the side of the substrate opposite the applied coating, in particular if the substrate is at least partially transparent, as in the case of the use of films , Glass or the like. In this case, part of the light is reflected on the surface of the coating, wherein a further part of the light penetrates the coating and is only reflected on the surface of the substrate. The reflected radiation, which comprises an interference of the radiation reflected at the substrate and the coating and possibly the irradiated radiation, can then be detected by the detector. For example, by comparison with a model, the layer thickness can be determined on the basis of the reflected radiation by evaluating the reflected radiation.

A transmission device may, in particular, be understood to mean a device which has a radiation source and a detector, wherein the radiation source and the detector are arranged on different sides of the substrate, so that the radiation emitted by the radiation source can radiate through the substrate together with the coating. As a result, with the knowledge of the radiation emitted by the radiation source and of the transmitted radiation, the degree of radiation absorbed by the coating can be determined, which also draws conclusions regarding the Layer thickness allows. This in turn can find a suitable computer model use. A transmission device may be suitable in particular when using transparent substrates.

The measurement can take place with respect to a moving substrate immediately after the respective coating process in order to obtain the most accurate and reliable measured values, so that the reflectometric device and / or the transmission device can advantageously be arranged immediately after a coating position or after an exit opening of the evaporation container. Consequently, in this embodiment, in particular a total layer thickness can be determined as the addition of individual layer thicknesses. Advantageously, the layer thickness in this embodiment can be determined after each coating step. In this case, the layer thickness can be determined starting from a known system, wherein the system can be calibrated after each coating step by the previously determined layer thicknesses.

Further units, such as a polarizer or the like, may be expediently encompassed by the reflectometric device and / or transmission device.

In this refinement, the wavelength-dependent reflection and transmittance of the layer stack can thus be measured by means of a reflection and / or transmission spectrum, and with its help, and in particular with a computer-aided simulation, the last applied layer thickness can be determined. If the duration of the coating process is known, an exact conclusion about the coating rate is possible. The coating rate can be determined exactly here, in particular without any interfering influences, which for example reduce or change the deposition of a material vapor present in the gas phase. As a result, it is furthermore possible to control or regulate the coating process using the determined coating rate.

The arrangement according to the invention is particularly advantageous in this embodiment in order to obtain exact results with respect to the coating rate. Thus, for example, the disadvantages of reflectometry, transmission measurement or absorption spectroscopy, which due to the application can be quite negligible and / or tolerable, can be overcome. The absorption spectroscopy provides the measurement signals of the evaporation rates of each individual evaporator, the reflectometry and / or transmission measurement in addition to the measurement signal of the resulting absolute layer thicknesses. The coating rate may also be additionally or alternatively adjusted by varying overspeed of the substrate.

Within the scope of a further embodiment, the radiation chopper can comprise a rotatable disk having at least one radiation-impermeable region and at least one radiation-transmissive region. This is a particularly simple, safe and durable design to modulate the radiation emitted by the radiation source continuously in time-limited radiation pulses. In this case, the disk, which can also be referred to as a chopper wheel, have any desired number of radiation-transmissive regions and radiation-impermeable regions, so that the temporal pulse sequence of the emitted radiation can be adjustable by the rotational speed of the disk. In this case, the disk or a region of the disk can preferably completely cover the radiation cone of the radiation source. Furthermore, the at least one radiation-transmissive region and the at least one radiation-impermeable region can advantageously be arranged in such a way that they cover the radiation cone of the radiation source successively in a rotation of the disk about its axis.

In a further embodiment, at least two evaporation containers may be provided, on which the substrate to be coated can be guided successively, wherein an absorption spectroscopic device for optically detecting the vapor density of the evaporated coating material is provided downstream of the outlet opening of at least one evaporation container with respect to the evaporated coating material, and downstream the outlet opening of at least one evaporation container is provided with respect to the along-guided substrate a reflectometric and / or transmission device for optically detecting the layer thickness of the deposited coating. This is a particularly effective arrangement for combining the positive effects of the absorption spectroscopic device with those of a reflectometric and / or transmissive device. As a result, particularly accurate results with respect to the coating rate can be determined.

It is understood by those skilled in the art that a corresponding reflectometric and / or transmission device can be provided even in the presence of more than two evaporation tanks, in particular between each or all of the two evaporation tanks. Optionally, alternatively or additionally, a reflectometric and / or Transmission device may be provided after the last passed from the substrate evaporation tank to determine the final applied layer thickness or applied by the last evaporation tank layer thickness. Further, an absorption spectroscopic device may be provided for each evaporation tank.

In the context of a further embodiment, the outlet opening can be designed linear. As a result, in addition to the setting of particularly high coating rates, by setting a variable geometry of the outlet opening, for example in comparison to punctiform sputtering sources, a very rapid change of the discharged organic coating material is possible, whereby very dynamic coating processes are particularly effective. In particular, in the case of coating processes with organic vaporization material using absorption spectroscopy, effects thus occur which improve the individual advantages, in particular with regard to dynamic control.

In detail, the evaporation container, in particular in this embodiment, may be a tube oriented in particular transversely to the direction of substrate movement, preferably with a circular cross-section. Most preferably, the tube is thin-walled and / or formed of metal and slotted in the direction of its longitudinal extent, preferably on the substrate facing the top of the tube. The longitudinal slot of the tube preferably forms the outlet opening, through which organic material which has evaporated approximately can flow directly to the substrate to be coated. The slot-shaped outlet opening preferably has a small width relative to the pipe diameter. It thereby forms a throttle point, which generates a very homogeneous distribution of the steam flow over the entire length of the evaporator, even with an uneven distribution of the coating material in the evaporation tube with a suitable design. Due to the adjustable diameter and the length of the tube, preferably made of metal, a large storage volume of organic material to be vaporized can be obtained, so that when using the evaporator in inline coating systems a very long operating time to the necessary refilling approximately within a Maintenance cycle can be achieved.

In a further embodiment, the absorption spectroscopic device may comprise a photomultiplier as a detector. Such detectors are particularly advantageous for coating processes with organic coating material, since they can detect even the smallest measuring signals safely and accurately, and furthermore can be combined well with the amplification unit used according to the invention.

In a further embodiment, the arrangement may further comprise a quartz crystal microbalance (QCM). A combination of absorption spectroscopy, such as along with reflectometry and / or transmission methods, as well as a quartz crystal microbalance can have particular advantages, for example, when coating material is evaporated at the lowest rate and at least partially below the detection limit of the absorption spectroscopy. Also in this embodiment, the determination of the coating rate or the control of the atomic / molecular evaporator can no longer be controlled solely by the rate signal of the quartz crystal microbalance, but rather via a combination of several measurement signals that can be processed in-situ by means of computer simulation. Quartz crystal microbalances are microbalances whose sensor is based on a quartz crystal. In this case, the piezoelectric property of quartz is used, which leads to a change in frequency of the quartz crystal, which is dependent on the mass of adsorbed on a surface of the quartz material.

In a further embodiment, a control unit may be provided, which is connected to the amplification unit and is further configured to control a coating process on the basis of the data determined by the absorption spectroscopic device. As a result, it is possible to react directly to the determined coating rate so as to be able to set or maintain the layer thicknesses or a mixing ratio as desired. In detail, for example, the control unit can be connected to the heat source acting on the coating material and adjust it so that it heats up, for example, if the coating rate is too low and it is cooled accordingly if the coating rate is too high. By way of further example, the exit opening of the evaporation vessel through which the vaporized molecules escape in the direction of the substrate can be mechanically reduced or enlarged so that, depending on the desired adaptation, fewer or more molecules per time interval can leave the evaporation vessel, ie the coating rate is also adjusted becomes. For this purpose, the control unit can be connected to a device for reducing and / or enlarging the effective outlet opening. Furthermore, for example, a crossing speed of the substrate can be adjusted.

The control unit, which may be a control unit, may conveniently comprise a program which is based on the determined Data of the coating rate, a control signal or control signal calculate and send to the coating unit, ie in particular to the heat source or a further adjustment for varying, for example, the degree of evaporation or the exit amount of the coating material from the evaporation vessel.

Furthermore, in the event that a reflectometric and / or transmission device and / or a quartz crystal microbalance is provided, the control unit may additionally be connected to it or to this. As a result, the coating process can be controlled or regulated even more precisely.

The present invention further relates to a method for coating a substrate with an organic coating material using an arrangement according to the invention, wherein the coating rate is determined at least by the absorption spectroscopic device using the reinforcing unit and the deposition of the organic coating material is controlled on the basis of the determined coating rate. As a result, a particularly dynamic, accurate and effective coating process can be made possible, which also gives very good results in organic coating materials. With regard to further advantages, reference is also made to the comments on the inventive arrangement.

Within the scope of an embodiment, an arrangement comprising an evaporation container with a linear outlet opening can be used and the coating rate can be controlled by setting an opening state of the outlet opening. As a result, the coating rate can be controlled or regulated particularly quickly and dynamically in particularly wide ranges. Consequently, the advantages of a dynamic coating process of an organic coating material, particularly in this embodiment, can be particularly advantageous. The setting of the opening state can mean in particular the size of the provided opening and / or the geometry of the provided opening in the sense of the present invention.

The present invention further relates to the use of an arrangement according to the invention and / or a method according to the invention for coating a substrate with an organic coating material.

Drawings and examples

Further advantages and advantageous embodiments of the subject invention are illustrated by the drawings and explained in the following description. It should be noted that the drawings have only descriptive character and are not intended to limit the invention in any way. Show it

1 a schematic representation of an embodiment of an inventive arrangement; and

2 a schematic representation of another embodiment of an inventive arrangement.

In 1 is an embodiment of the arrangement according to the invention 10 for coating a substrate 12 shown with an organic coating material. By means of the arrangement according to the invention 10 is on the substrate 12 an organic coating 14 producible, in particular by a coating material 16 is evaporated, to the substrate 12 flows and condenses there. Here is a control of punctiform and in particular linear evaporator sources, comprising an evaporation tank 18 and a heat source 20 , for coating applications with high dynamic coating rates, such as those suitable for the production of solar cells or light-emitting diodes.

Precise measurement and control of the coating rates or evaporation rates can be a necessary prerequisite, particularly in the case of organic photovoltaics, in order to be able to produce powerful and stable solar cells in a large area. If the evaporation rate of an evaporator changes during the coating process of mixed layers, this leads to a different mixing ratio of the materials in the layer. This results in, for example, in the organic solar cells or OLEDs losses in efficiency and service life.

In particular, in such applications, on the one hand, a precise control (+/- 5%) together with or alternatively with high dynamic rates (> 50 nm · m / min) may be desired in order to ensure a consistent layer thickness, which with the inventive arrangement 10 easily possible.

The order 10 comprises at least one, for example, tubular evaporation vessel 18 for receiving organic coating material 16 and at least one heat source 20 for evaporation of the coating material 16 , The evaporation tank 18 as well as the heat source 20 can in an example water-cooled housing 21 be arranged, which is about the radiation of the heat sources 20 on the evaporation tank 18 focus and prevent excessive heating of other parts of the system or protect the other parts of the system so. The evaporation tank 18 can also be transverse to a substrate movement direction A of the substrate 12 extend. The evaporation tank 18 includes an outlet opening 22 for evaporated coating material 16 , Through the outlet 22 can be perpendicular to the substrate movement direction A towards the substrate 12 evaporated coating material 16 flow out and so a coating cone 24 that form on the substrate 12 condenses and so does the coating 14 , trains.

The outlet opening 22 For example, it may form a line-shaped gap and may have a width of ≥ 30 cm. The heat source 20 or the heat sources 20 For example, they may be formed as or comprise double tube quartz radiators and, for example, on a circumference around the evaporation vessel 18 be arranged. Furthermore, the housing has 21 expediently an opening 23 to the exit of the coating cone 24 or the evaporated coating material 16 on.

It is also at least one absorption spectroscopic device 26 for detecting the vapor density of the evaporated coating material 16 intended. This can be inside the case 21 or even outside the case 21 and here in particular at radiation openings 28 and 30 , such as glass windows, of the housing 21 be arranged. This may cause a radiation source 32 the absorption spectroscopic arrangement 26 a defined light beam 34 to a detector 36 , such as a photomultiplier, of the absorption spectroscopic array 26 conduct.

Is the outlet opening 22 designed line-shaped, the absorption spectroscopic arrangement radiates through 26 advantageously the largest width of the coating cone 24 , Consequently, in this case, the radiation source 32 and the detector 36 arranged such that the light beam 34 the coating cone 24 radiates and parallel to the gap of the outlet opening 22 and thus in particular parallel to the longitudinal extent of the evaporation tank 18 runs.

The order 10 further comprises a gain unit comprising a radiation chopper 37 for generating a temporally periodic pulse train of radiation pulses by the radiation source and a lock-in amplifier 38 on. The light beam radiates through 34 the coating cone 24 of the organic coating material 16 , the vapor density and thereby the coating rate of organic coating material can be determined.

In one embodiment, the arrangement 10 further a reflectometric device 40 and / or a transmission device 42 for determining the layer thickness of the on the substrate 12 applied organic coating 14 exhibit. In this embodiment, with respect to the reflectometric device 40 in particular a light source 44 and a detector 46 be provided. This can cause an emitted light beam 48 . 50 on the substrate 12 or on the coating 14 shine on the substrate 12 or on the coating 14 be reflected and reflected beam 52 . 54 to the detector 46 radiate where it is detectable. Regarding the transmission device 42 may also be a radiation source with the radiation source 44 the reflectometric device may be identical, as well as a detector 56 for detecting the substrate 12 and the coating 14 radiating radiation 58 be provided.

In a further embodiment, in addition to the above-described devices for optically detecting a coating rate, a quartz crystal microbalance 60 be provided in the coating cone 24 can be arranged.

In a further embodiment, a control unit 61 be provided with the absorption spectroscopic device 26 or with the amplification unit and optionally with the reflectometric device 40 and / or the transmission device 42 and / or the quartz crystal microbalance 60 connected is. The control unit 61 can then be configured to a coating process on the basis of the absorption spectroscopic device 26 and optionally from the reflectometric device 40 and / or the transmission device 42 and / or the quartz crystal microbalance 60 control the data collected. This can be done by the control unit 61 for example, with the evaporation tank 18 or with a device for adjusting the outlet opening 22 and / or with the one or more heat sources 20 be connected so as to the coating process or the coating rate, such as by adjusting the temperature of the heat source 20 or by adjusting an opening state of the outlet opening 22 to control.

By the arrangement according to the invention 10 Thus, in principle, the following analytical methods or analytical devices are applicable for determining the coating rate: Absorption spectroscopy in conjunction with a quartz crystal Microbalance; Absorption spectroscopy in conjunction with reflectometry; Absorption spectroscopy in connection with transmission methods; Absorption spectroscopy in conjunction with a quartz crystal microbalance and with reflectometry; Absorption spectroscopy in conjunction with a quartz crystal microbalance and with transmission methods; Absorption spectroscopy in conjunction with reflectometry and transmission methods; and / or absorption spectroscopy in conjunction with a quartz crystal microbalance in combination with reflectometry and transmission methods.

As it is in a coating process for organic coating materials 16 In particular, can act to vacuum processes, all in the 1 shown elements are arranged in a vacuum chamber, not shown. Furthermore, the substrate 12 , are passed through the vacuum chamber, such as through vacuum-tight openings. In addition, in particular, the absorption spectroscopic device 26 , the reflectometric device 40 and / or the transmission device 42 be arranged completely or partially outside the vacuum chamber. In this case, for example, light beams can be guided through vacuum-tight windows or light guides to the desired application position.

In 2 another embodiment of the present invention is shown. According to 2 are at least two evaporation tanks 18 provided on which the substrate to be coated 12 successively, that is, in particular, can be guided in succession, wherein downstream of the outlet opening 22 at least one evaporation tank 18 with respect to the evaporated coating material 16 in particular an absorption spectroscopic arrangement 26 for optically detecting the vapor density of the evaporated coating material 16 is provided, and wherein downstream of the outlet opening 22 at least one evaporation tank 18 with respect to the along-guided substrate 12 a reflectometric 40 and / or transmission device 42 for optically detecting the layer thickness of the deposited coating 14 . 15 is provided. 2 is shown greatly simplified to explain the principle of this embodiment. Basically, in a manner understandable to those skilled in all in 1 be provided components shown. In detail are in 2 only the case 21 with interposed reflectometric device 40 and transmission device 42 as well as with radiation source 32 and detector 36 the absorption spectroscopic devices 26 shown. It will be apparent to those skilled in the art that the reinforcing unit is also in the embodiment according to 2 should be present.

2 further shows that a rolling device 62 for unrolling a particular film-shaped substrate to be coated 12 and a retractor 64 for rolling up the coated substrate 12 may be provided, wherein the rolling device 62 and the retractor 64 are arranged such that during a rolling process and / or during a rolling up of the substrate 12 this at least one outlet opening 22 is feasible along. It can after the first outlet 22 a coating 14 and after the second outlet opening, a further coating 15 on the substrate 12 be applied.

Again, according to 2 all elements shown are arranged in a vacuum chamber, not shown. Furthermore, the substrate 12 , are passed through the vacuum chamber, such as through vacuum-tight openings. In addition, in particular, the absorption spectroscopic device 26 , the reflectometric device 40 and / or the transmission device can be arranged completely or partially outside the vacuum chamber. In this case, for example, light beams can be guided through vacuum-tight windows or light guides to the desired application position.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008043634 A1 [0005]
• DE 102009029236 A1 [0006]

Claims (11)

Arrangement for coating a substrate ( 12 ) with an organic coating material ( 16 ) comprising at least one evaporation vessel ( 18 ) for receiving organic coating material ( 16 ) and at least one heat source ( 20 ) for evaporating the organic coating material ( 16 ), wherein the evaporation tank ( 18 ) an outlet opening ( 22 ) for evaporated organic coating material ( 16 ), and wherein at least one absorption spectroscopic arrangement ( 26 ) with a radiation source ( 32 ) and a detector ( 36 ) for detecting the vapor density of the evaporated coating material ( 16 ), and wherein the arrangement ( 10 ) further with the absorption spectroscopic device ( 26 ) having a radiation chopper ( 37 ) for generating a temporally periodic pulse sequence of radiation pulses by the radiation source ( 32 ) and a lock-in amplifier ( 38 ). Arrangement according to claim 1, wherein the arrangement ( 10 ) further comprises a reflectometric device ( 40 ) and / or a transmission device ( 42 ) for determining the layer thickness of a on the substrate ( 12 ) applied organic coating ( 14 . 15 ) having. Arrangement according to claim 1 or 2, wherein the radiation chopper ( 37 ) comprises a rotatable disc having at least one radiopaque region and at least one radiation transmissive region. Arrangement according to claim 1 or 2, wherein at least two evaporation tanks ( 18 ) are provided, on which the substrate to be coated ( 12 ) is guided along successively, wherein downstream of the outlet opening ( 22 ) at least one evaporation tank ( 18 ) with respect to the evaporated coating material ( 16 ), in particular an absorption spectroscopic arrangement ( 26 ) for optically detecting the vapor density of the evaporated coating material ( 16 ) is provided, and wherein downstream of the outlet opening ( 22 ) at least one evaporation tank ( 18 ) with respect to the along-guided substrate ( 12 ) a reflectometric device ( 40 ) and / or a transmission device ( 42 ) for optically detecting the layer thickness of the deposited coating ( 14 . 15 ) is provided. Arrangement according to one of claims 1 to 4, wherein the outlet opening ( 22 ) is designed linear. Arrangement according to one of claims 1 to 5, wherein the absorption spectroscopic device ( 26 ) a photomultiplier as a detector ( 36 ) having. Arrangement according to one of claims 1 to 6, wherein the arrangement ( 10 ) a quartz crystal microbalance ( 60 ) having. Arrangement according to one of claims 1 to 7, wherein a control unit ( 61 ), which is connected to the amplification unit and is further configured in such a way, a coating process on the basis of the absorption spectroscopic device ( 26 ) to control the data obtained. Process for coating a substrate ( 12 ) with an organic coating material ( 16 ) using an arrangement ( 10 ) according to one of claims 1 to 7, wherein the coating rate is determined at least by the absorption spectroscopic device ( 26 ) is determined using the reinforcing unit and the deposition of the organic coating material ( 16 ) is controlled on the basis of the determined coating rate. Method according to claim 9, wherein an arrangement ( 10 ) comprising an evaporation tank ( 18 ) with a linear outlet opening ( 22 ) is used and the coating rate by adjusting an opening state of the outlet opening ( 22 ) is controlled. Use of an arrangement ( 10 ) according to one of claims 1 to 8 and / or a method according to claim 8 or 9 for coating a substrate ( 12 ) with an organic coating material ( 16 ).

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