Coating apparatus with rotation module

The present invention refers to a method for coating a substrate, a coating apparatus for carrying out the method and a handling module for coating apparatuses. The handling module comprises a moveable support for a substrate to be coated the support being movable between at least two positions. Further, a mask arranging device for at least one of attaching and detaching a mask to the substrate, and a mask alignment device for aligning the mask with respect to the substrate are provided for, wherein the mask alignment device is attached to the movable support so as to be movable together with the support. Alternatively, the handling module comprises a vacuum chamber, a moveable support for a substrate to be coated, the support being arranged in the vacuum chamber and being rotatable between at least two positions, wherein a mask arranging device for at least one of attaching and detaching a mask to the substrate is arranged within the vacuum chamber of the handling module.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention refers to a handling module for a coating apparatus as well as a coating apparatus for depositing at least one, preferably two or more layers on a substrate and a method for coating a substrate in such a coating apparatus.

2. Prior Art

In modern technology and industry coating processes are very important, since a lot of products comprise coatings or layers which have to be applied on the products or substrates. For example, displays for television apparatuses or computer monitors may comprise a plurality of layers which have to be applied on a glass substrate. This is especially true for so-called OLED-displays, monitors or television screens, which comprise organic light emitting diodes. These organic light emitting diodes are composed of a plurality of layers which are deposited one after the other. In order to have separate pixels which can be activated independently, layers have to be structured or patterned. In order to achieve a structure or pattern, masks are used during the coating process. Accordingly, different masks for different layers have to be used and during the production process the masks have to be arranged and removed from the substrate for several times.

Another application for organic light emitting diodes is their use in lighting devices. The fabrication is less complex compared to display technology, since the different RGB (Red Green Blue)—layers do not have to be offset to each other. Nevertheless, several thin layers have to be deposited.

EP 17 173 39 A2 discloses a continuously working in-line coating apparatus in which a substrate to be coated is travelling along a coating path, the substrate being coated with different layers or treated by corresponding pre- or after-treatments. Along the coating path having a transport path for the substrates included therein rotation modules are provided for, which allow to transfer the substrate to a mask-exchange station and to transport back the masks to the beginning of a specific coating section so as to be re-used for a new substrate. Due to the in-line design of such an apparatus, a very effective coating of the substrates can be achieved. However, such an apparatus requires lot of space for the coating path and the transport paths of the masks.

Another apparatus for manufacturing an organic electroluminescence display is disclosed in US 2002/0187265 A1. According to this concept, a lot of coating sections for depositing single layers are disposed one after the other, while each of the coating sections comprise one central handling chamber with a transfer robot and adjacent coating and treatment chambers around the handling chamber. Such a design may save some space and therefore the space requirements are reduced, however, due to separate chambers for preparing the substrate before coating, still huge space is required for such an apparatus. Moreover, a great number of transfer steps by the transfer robot with respect to the surrounding treatment and coating chambers make such a coating apparatus not very effective for mass production.

A mixed concept for a continuous and discontinuous transport through an in-line coating apparatus is disclosed in DE 102 05 167 C5. According to this concept, a rotation module is disposed at the end of a continuously working conveyor transporting the substrates through vacuum coating chambers. Since the rotation module comprises several retainers for receiving substrates, the rotation module may act as a buffer chamber for disrupting continuous transport. However, additional buffer chambers can lead to even more required space.

WO 2007/038427 A2 discloses a method and an apparatus for electronic device manufacture using shadow masks with a continuous in-line design. According to this apparatus, a plurality of deposition vessels are arranged one after the other and every deposition vessel has at least two shadow masks associated therewith. The two masks can be alternately positioned for patterning the deposition material during deposition and for cleaning in adjacent cleaning vessels. Thus, throughput can be increased, but the required space is also increased.

DISCLOSURE OF THE INVENTION

Object of the Invention

Although the methods and apparatuses known from prior art provide good results with respect to the deposition of multi-layer coatings and especially OLED devices, there is still the need for optimizing such apparatuses and the corresponding coating methods with respect to efficiency and necessary effort, especially in terms of space requirements. In addition, these objects should be achieved while simultaneously maintaining a high quality deposition. Further, the apparatus should be usable for different coatings and layer stacks and should therefore provide flexibility with respect to the kind of utilization. Accordingly, it is an object of the present invention to provide an apparatus as well as a method for coating a substrate which enables an improvement with respect to all of these objects.

Technical Solution

The present invention is based on the finding that a handling module for transferring a substrate from one part of a coating apparatus to another part allows for very effective and space-saving design of the coating apparatus, if a mask arranging and/or mask alignment device is included in the handling module. Due to the integration of the mask arranging and/or mask alignment in the handling module, the efficiency can also be increased, since it is not necessary to transfer the substrate to a specific mask arrangement and/or alignment station. Thus, according to the present invention the integration of the mask arrangement and/or alignment station(s) allows to carry out the mask arrangement and/or alignment processes at positions of the substrate which the substrate takes during normal processing in the handling module. Accordingly, no additional positions for mask arrangement and/or mask alignment have to be run into. Thus, additional components like mask arrangement or mask alignment chambers are no longer necessary. Further, additional transport steps for the substrate may be avoided. As a consequence effectivity is increased and space requirements are decreased. In addition, the integration of mask arrangement and/or alignment into the handling module also enables the provision of a plurality of independently working coating areas or coating sections so that the flexibility of the apparatus is enhanced and the processes in the coating areas or sections can be optimized independently. Moreover, design of the whole coating apparatus becomes more flexible.

Thus, according to a first aspect of the present invention a handling module for a coating apparatus comprises a movable support for a substrate to be coated. The movable support is movable between at least two positions so that the handling module can transfer the substrate from one part of the coating apparatus to another, and/or exchange components, like masks, for the subsequent coating process. Furthermore, the handling module comprises a mask arranging device for attaching and/or detaching a mask to and/or from the substrate as well as a mask alignment device for aligning the mask with respect to the substrate. For an efficient alignment of the mask with high quality, the invention suggests to attach the mask alignment device at the movable support of the handling module so as to be movable together with the support. While it is advantageous to have the mask arrangement device and the mask alignment device integrated in one mask manipulating device, this aspect of the invention also covers embodiments where the mask arrangement device is separate from the mask alignment device.

The handling module according to the first aspect of the invention may be used in a vacuum coating apparatus. Accordingly, the handling module may comprise a vacuum chamber.

Especially for vacuum coating apparatuses it is necessary to realize a space-saving design. Accordingly, the movable support may be a rotation type support which is rotatable around a rotation axis, since such a design is very space-saving.

As mentioned above, the mask arrangement device and the mask alignment device may be integrated into one mask manipulating apparatus, but may also be separated into two single devices. In the latter case, it is advantageous to at least include the mask arrangement device into the central vacuum chamber of the handling module, which also encompasses the movable support, to enable direct access to the movable support and thus to the substrate without the need of additional chambers for mask arrangement and of additional transport of the substrate.

Such a rotation type handling module may comprise a vacuum chamber, the chamber walls of which are all facing the rotation axis of the movable support, while the form may be different and can be chosen according to the requirements in a rectangular, square, pentagonal, hexagonal or octagonal cross section in a plane transverse the rotation axis. Accordingly, the expression “within the vacuum chamber” is to be understood in a way that the space between the surrounding chamber walls and the rotation axis of the movable support is meant, so that a direct access to the movable support may be achieved.

According to a second aspect of the present invention, for which protection is sought independently and in combination with other aspects of the invention, the handling module is especially designed to be part of a vacuum coating apparatus.

Accordingly, the handling module comprises a vacuum chamber so that a substrate can be transferred or handled under vacuum conditions. Further, the handling module according to the second aspect of the invention comprises also a movable support for a substrate to be coated. The movable support is rotatable around a rotation axis, so that at least two positions can be set to transfer the substrate from one part of the coating apparatus to another part of the coating apparatus and/or to exchange components, like masks. Such a vacuum rotation module is moreover designed such that at least one mask arranging device for attaching and/or detaching a mask to and/or from a substrate is arranged within the vacuum chamber of the handling module. Thus, the efficiency and flexibility of a coating apparatus having such a handling module as well as the quality of the coating deposited by such an apparatus can be increased, since the different coating sections are separated by the handling modules and do not affect each other.

Similar to the invention according to the first aspect, the mask arrangement device and/or the mask alignment device may be attached to the movable support so as to be moved together with the movable support. Such a design allows including of the mask arrangement device and/or of the mask alignment device in the inner space of the vacuum chamber without being in contact with the surrounding chamber walls. Accordingly, neither mask arrangement processes nor mask alignment processes are influenced by position deviations of the vacuum chamber walls due to pressure differences between inside and outside of the vacuum chamber.

The movable support may comprise at least two retainers for receiving a substrate, so that it is possible to carry more than one substrate at the same time. Accordingly, three, four, five retainers or any integer number of retainers are conceivable. Thus, the efficiency may further be increased.

Since the movable support may be a rotatable support, where the substrates are supported with their main surfaces being parallel to the rotation axis, a design for the movable support may be chosen in which the retainers are disposed such that the main or biggest side of the retainers is parallel to the rotation axis of the movable support. The at least two retainers or pairs of retainers may be arranged with their backsides to each other and the rotation axis may be located between the two retainers.

As mentioned above, the number of retainers is not restricted to two. More retainers, namely three retainers, four retainers or even more retainers are conceivable. The retainers may be arranged at the main surfaces of a cuboid or any hexagon or octagon, or similar body and the rotation axis may be the central longitudinal axis of such a body.

The retainers of the support may receive the substrates directly or via substrate carriers on which the substrates are located during movement through the coating apparatus.

Preferably, the substrates are coated with a vertical position of the surface to be coated. Deviations to the vertical direction may be within an angle of ±40°, preferably ±20° to the vertical direction.

If the mask arrangement device and/or the mask alignment device are not attached at the movable support, they may be located within the vacuum chamber of the handling module, especially the central vacuum chamber at at least one position opposite to a retainer in at least one of the positions of the movable support. This means that the position of the mask arrangement device and/or mask alignment device is adapted to a position of the movable support directly in the inner core space of the handling module where the movable support is located.

The mask arranging device and the mask alignment device may be realized by a single mask manipulating apparatus. Thus, the movement of the substrate and/or the mask for approaching the mask and the substrate as well as the movement of substrate and/or mask for aligning substrate and mask can be performed by a single device so that the effort for separate devices can be saved. Although it is conceivable to only move the substrate or the substrate and the mask simultaneously for arranging and aligning of the mask at the substrate, it may be advantageous to only move the mask for such purposes. Accordingly, the mask manipulating apparatus, or if separated devices are used, the mask arranging device and/or mask alignment device may be arranged opposite to a retainer for the substrate at the movable support for the substrates. In combination with a rotatable support with a rotation axis located centrally within the handling module, a very advantageous design is achieved. Since the mask manipulating apparatus or the single mask arranging devices and/or mask alignment devices may be moved together with the substrate support, a fixed relationship between these devices may be achieved so that additional effort for aligning the substrate support and the mask manipulating device can be omitted. Further, the mask arranging and/or mask alignment device is not influenced by the difference between the vacuum conditions inside the handling module and the atmosphere conditions outside the handling module, since the mask arranging and/or aligning device is completely received in the handling module without any contact to the housing of the handling module except via the rotation axis.

The movable support for the substrates may comprise a frame having a plate-, cuboid- or prism-like form, the rotation axis extending along the central longitudinal axis of the plate-, cuboid- or prism-like frame and the retainers being disposed at the sidewalls parallel to the longitudinal axis of the frame. In order to dispose the mask arranging device and/or mask alignment device (mask manipulating device) a holder having a U-bent or U-shaped construction extends from the top area of the frame to a bottom area of the frame so that a space is defined between the substrate retainers and the U-bent or U-shaped holder for the mask manipulating device.

Although every suitable device for arranging and/or aligning a mask at the substrate as well as removing the mask from the substrate may be used, a six axes parallel kinematic may be disposed as a mask manipulating device. Such a six axes parallel kinematic comprises a mounting base and struts or legs which connect the mounting base with a movable platform. Usually six legs or struts are disposed which can be elongated and activated independently. Due to the articulated connection between the legs and the movable platform on the one side and the mounting base on the other side, especially by gimbal connections, the movable platform can be moved and aligned in six independent degrees of freedom of motion.

The movable support of the handling module may have at least two positions into which the movable support can be moved. At least three openings in the housing of the handling module may be assigned to these two positions so that the substrates and the masks can be exchanged with adjacent components of the coating apparatus, like the mask magazine or the coating path for the substrate. However, it is possible that the movable support may be brought in more than two positions and the handling module may have an appropriate number of chamber walls or sidewalls and openings for the exchange with adjacent devices. Accordingly, a movable support may be rotated by 30°, 45°, 60°, 90°, 120° and multiple thereof and the cross-sectional shape of the vacuum chamber may be rectangular, pentagonal, hexagonal, octagonal etc.

The devices which may be connected to the module may comprise buffer chambers, mask storage magazines, transport chambers, load lock chambers, treatment chambers, coating chambers and similar.

A transport chamber is defined as a chamber where only the transport of the substrate is carried out, while treatment or coating chambers are characterized by the fact that additional to a transport or exclusively treatments, like pre-treatments or after-treatments of the substrate, as well as coating processes are carried out.

A coating apparatus for depositing at least one, preferably two or more layers on a substrate may be designed such that at least one, preferably two deposition areas are provided for. Each deposition area is equipped to perform at least a complete deposition of one layer. The expression “layer” may include for the purpose of this application partial layers of a layer stack having the same or different compositions as well as non-continuous layers, especially patterned layers. At the inlet and the outlet of the deposition area, a rotation-type handling module as described above is arranged according to the present invention. The inlet and outlet for loading and unloading the substrates into the coating apparatus may be separately arranged at different or the same rotation-type handling module or may be integrated into one loading and unloading device.

Due to the connection of the coating areas by the handling modules of the present invention, the deposition areas can be efficiently and independently operated. Only the transfer from one deposition area to the other deposition area has to be adapted by adjusting the work cycle of the rotation or handling modules.

The deposition areas may comprise different devices or apparatuses for depositing layers like continuous coating paths or coating chambers for static and/or wobble deposition. Any suitable device or apparatus for depositing a coating layer may be connected to the rotation type handling module.

For establishing a continuous coating path a plurality of twin-type coating chambers each having two compartments back to back adjacent to each other may be provided for. Twin-type coating chambers allow for continuous transport of the substrate in one compartment in one direction and in the adjacent compartment in the opposite direction so that a space-saving design for a continuous coating path is achieved. In order to realize a change of the movement direction a rotation unit for a U-turn of the substrate is provided at one end of the coating path opposite to the handling or rotation module. However, this rotation unit does not need to have mask arrangement and/or mask alignment devices.

Instead of a continuous coating path comprising a rotation unit for changing the movement direction of the substrate, a back-and-forth continuous coating path may be established, in which the substrate to be coated is moved on the same transport path in opposite directions. Accordingly, such a back-and-forth continuous coating path may be realised in a single type coating chamber, since no additional space for the back transport of the substrate has to be provided for. However, two back-and-forth continuous coating paths may be arranged side to side in twin-type coating chambers using separately the two independent coating paths provided by the twin-type coating chamber for the back-and-forth movement of the substrate.

A handling module, a coating area and a mask magazine connected to the handling module may build a coating section. Several coating sections may be disposed one after the other in a coating apparatus for producing a coating with a plurality of layers. The coating sections may be connected to each other via the handling modules. For this purpose, buffer chambers and/or transport chambers may be disposed between adjacent handling or rotation modules. However, the handling or rotation modules may also be connected directly to each other.

In addition, the first rotation type handling module or the first coating section of a coating apparatus may comprise substrate loading sections for introducing the substrate into the vacuum coating apparatus, while the last rotation module or the last coating section of a coating apparatus may comprise a substrate unloading section.

By using the inventive rotation type handling module several advantageous designs of coating apparatuses may be realised. In addition to the type of coating apparatuses having a plurality of coating sections, each being built by a handling module, a coating area and a mask magazine other types using only one rotation type handling module may be implemented. For such a coating apparatus a single mask storage unit being connected to the rotation type handling module may be used for storing and providing of different masks for the coating areas connected to the single rotation type handling module. Thus, a plurality of mask storage units may be omitted.

Similar to the previously described coating apparatus having several rotation type handling modules different types of coating areas may be used together with the single rotation type handling module. Since no further rotation type handling module for mask arrangement and/or mask alignment is available in the coating area, only such coating areas may be used which do not need mask change within the deposition process carried out in the respective coating area.

Accordingly, continuous coating path with a back-and-forth movement of the substrate at the same transport path being realised in a single type or twin type vacuum chamber may be used. Moreover, a continuous coating path using a twin type vacuum chamber with separated movement path for the opposite movement directions may be used, if a rotation unit for turning the movement direction of the substrates is provided for.

In addition to a single, central mask storage unit for storing different types of masks used in the coating apparatus with a single rotation type handling unit and in addition to the at least two or preferably several deposition areas, at least one central loading and/or unloading section for the substrates is provided at the rotation type handling module. The substrate loading section and the substrate unloading section may be separate or combined in one device. Especially, the substrate loading and unloading section may load and unload the substrates at the same transport path. In order to increase the through-put two or more loading and unloading sections may be connected to the rotation type handling module.

The operation of a coating apparatus using a rotation type handling module according to the present invention is especially characterized by the arranging and/or aligning of the mask at the substrate within the rotation type handling module. Due to the design of the coating apparatuses with such a rotation type handling module, the substrates are running through the rotation type module at the beginning and at the end of the coating process carried out in the deposition areas of the apparatus. However, in some cases where no mask is necessary during the coating process, the coating apparatus may comprise additional sections where no rotation type handling module is present. However, for apparatuses having a design with a single rotation type handling module the substrates have to run through the rotation type handling module as the central transportation means, even if a deposition area is present in which no mask is necessary.

According to the design of the inventive coating apparatuses a mask may be attached to the substrate and removed from the substrate in the same rotation type handling module. Accordingly, the handling of the masks is easy. For the design with a single rotation type handling module only a single central mask storage unit may be used so that all masks for all deposition processes carried out in the coating apparatus are changed in the central rotation type handling unit.

As already described above, the rotation type handling module allows separating of different deposition areas so that no deposition process or coating process and no pre-treatment or any after-treatment of the substrate is preferably carried out in the handling module in order to maintain such separation which is beneficial to coating quality.

The components, devices, apparatuses and methods described above may be used for depositing any layer for which a mask is used, especially patterned layers, solar cell structures, OLED (organic light emitting diodes) structures, OLED displays, OLED lighting devices, thin film batteries etc.

EMBODIMENTS

FIG. 1shows a first example of an inventive coating apparatus for depositing two layers on a substrate. For carrying out the corresponding processes, the coating apparatus1comprises a loading path2with a lock chamber14and a transport chamber15. The lock chamber14allows bringing the substrate to be coated from atmosphere to high vacuum conditions set in the coating apparatus. Accordingly, the lock chamber14comprises two locks16and17at the outlet or inlet, respectively, of the lock chamber. When a new substrate is introduced into the lock chamber14, the lock16is closed and the lock17is opened so as to allow introducing the substrate. When the substrate is located in the lock chamber14, the lock17is closed and the lock chamber14is evacuated to the vacuum conditions set in the coating apparatus. When these vacuum conditions are achieved, the lock16is opened so as to allow the substrate to be moved to the transport chamber15. Alternatively, the lock chamber14may be disposed directly at the following rotation module4. However, interposing the transport chamber15enables to separate lock-in processes from the further movement of the substrate through the rotation type handling module4, in the following also designated as rotation module.

When the substrate located in transport chamber15is ready to move into the rotation module4, the movable support13is rotated such that a retainer on the substrate is aligned with the movement direction of the loading path2. Accordingly, the substrate or the substrate carrier on which the substrate is located can be moved by a linear motion towards the movable support so that the substrate or the substrate carrier with the substrate can be placed on the retainer of the movable support13. Since the mask magazine7is attached to the rotation module4at the side opposite to the side of the loading path2, at the same time a mask can be moved from the mask magazine7into the rotation module4so that the arranging and alignment device disposed in the rotation module4or at the movable support, respectively, can place the mask onto the substrate. After finishing the mask alignment, the substrate is ready for the first coating process.

Since the first coating path5is attached to the rotation module4at a side being rotated by 90° with respect to the sides where the mask magazine7as well as the loading path2are located, the movable support13is rotated around the rotation axis located in the centre of the rotation module4so that the retainer of the movable support13is aligned such with the first coating path5so as to allow the substrate or the substrate carrier, respectively, to be moved into the first coating path5(deposition area).

The first coating path5comprises several compartments18to21being placed in pairs of two back-to-back in twin-compartment chambers which define the coating path. Due to the twin-compartment construction of the coating chambers18,20and19,21a very space saving design of the coating apparatus1is possible. According to the example shown inFIG. 1, the substrate is moved according to the arrow shown in compartment18of the twin-compartment chamber18,20in the first compartments18to19of the chambers rightwards and thereafter leftwards in the second compartments20,21of the chambers. For carrying out the U-turn necessary for the substrate to be moved first in the compartments18and19in the first direction and afterwards in the compartments21and20in the opposite direction, a second type of a rotation module called rotation unit6is provided for. The rotation unit6is able to rotate the substrate or the substrate carrier by 180°. However, the rotation unit6does not comprise any additional devices like mask arranging or mask aligning devices or suchlike.

During movement in the twin-structure chambers or compartments18to21, the substrate is continuously coated by corresponding coating processes like sputter processes, chemical vapor deposition, physical vapor deposition and the like. The devices necessary for carrying out the coating processes as well as pre-treatment and/or after-treatment processes are not shown inFIG. 1. However, all kind of processes as mentioned before can be carried out in the vacuum compartments arranged along the first coating path5. Accordingly, the number of compartments may differ from that shown inFIG. 1.

As mentioned before, the substrate can be equipped with a mask during the coating process, as this is normally the case for the layers deposited for producing organic light emitting diode OLED-structures. However, if no mask is necessary for the coating process, the coating path5can also be used for a maskless deposition of a layer.

When a mask is used during the coating process in the first coating path5, the mask can be removed from the substrate in the rotation module4before leaving the rotation module4towards the second coating path11. For the purpose of mask removing, the movable support13is again rotated by 90° degree after receiving the substrate or substrate carrier from compartment20in order to align the movable support13with the mask magazine7and to allow the mask arranging device to remove the mask from the substrate and to transport the mask into the mask magazine7by linear movement from the movable support13to the mask magazine. Accordingly, the movable support13is oriented perpendicular to the position shown inFIG. 1.

After removing of the mask, the movable support is again rotated by 90° to be aligned with the moving direction of the transport chamber8connected to the rotation module4opposite to the first coating path5and the substrate or substrate carrier, respectively, is moved through the transport chamber8into a second rotation module10being identical or mirror symmetrical to the rotation module4. Accordingly, as shown for the rotation module4, the rotation module10also comprises a movable support which can be rotated in at least two positions in which the retainer of the movable support can be loaded with a substrate from the transport chamber8, a mask from the mask magazine9or a coated substrate from the compartment25of a second coating path11. In addition, the movable support of the second rotation module can also be positioned such that the substrate can leave the rotation module10into the compartment22or the unloading path3. Accordingly, at least two positions, namely positions rotated 90° to each other are possible for the movable support as shown for the first rotation module4. Preferably, the movable or rotatable support may adopt four positions each rotated 90°. If the movable support comprises two retainers disposed back-to-back with the rotation axis in between as described below with respect toFIG. 6, four positions of the movable support are advantageous, since each side of the movable support comprising a retainer can be positioned with respect to the left and right part of a side wall of the rotation module, for example the side walls of the rotation module where the mask magazine9or the second coating path11are connected to the rotation module10. This also applies to the rotation module4. In addition, the movable or rotatable support may be positioned in a different number of positions, e.g. three position or more than four positions, depending on the design of the chamber of the rotation module and the devices connected to the rotation module.

The unloading path3connected to the rotation module is identical to the loading path2with the only difference that the movement direction is opposite to that of the loading path2. Moreover, the locking process is also vice versa.

The coating apparatus1shown inFIG. 1comprises two independent parts, namely a coating section30and a coating section40which are connected by the transport chamber8. This design allows for independent coating processes with a very space and resources saving construction.

FIG. 2shows an example of a further inventive coating apparatus100which comprises identical components already described with respect toFIG. 1. Accordingly, such components which have the same reference number added by100are not described again. With respect to these reference numbers it is referred to the description ofFIG. 1.

Accordingly, the embodiment ofFIG. 2differs with respect to the embodiment ofFIG. 1only with respect to the number of coating sections and the arrangement of these sections within the coating apparatus100. As can be seen fromFIG. 2, the right coating section130and the left coating section140are almost identical to the coating sections30and40of the embodiment shown inFIG. 1. The coating section140is only adapted for depositing a top layer instead of a second coating so that this coating path111is designated as top-layer coating path111. The reason is that between the coating sections130and140coating sections150and160are provided for in the embodiment ofFIG. 2. This proves that the concept of the coating apparatus of the present invention is very flexible so that in a simple manner the apparatus100can be adapted to the needs of the coating to be produced. If, instead of two layer coating a layer stack comprising n-layers has to be produced, the coating apparatus100can be extended as shown inFIG. 2by arranging the appropriate number of coating sections160. Accordingly, this is schematically indicated by the separation lines170and171shown in the transport chambers180and181connecting the coating sections150and160as well as the coating section160with the coating section140, respectively. Accordingly, any number of layers in a layer stack can be produced one after the other. Only additional coating sections160had to be added to the coating apparatus100.

A substrate introduced into the coating apparatus100at the lock-chamber114of the loading path102is moved, as described before, to the rotation module104, provided with a mask from the mask magazine107and rotated by the movable support113so that it can be moved through compartments118and119to the rotation unit106. After making a U-turn in the rotation unit106and travelling afterwards through the compartments120and121back again to the rotation module104the mask is again removed in the rotation module104and stored in the mask magazine107. After leaving the rotation module104, the substrate is transferred through the transport channel108to the second coating section150.

The second coating section150comprises the rotation module151which is almost identical to the rotation module130of the coating section130. Only the connection of the rotation module151to adjacent transport chambers108or180as well as to coating chambers153,156and154,155or mask magazine152is slightly different with respect to the place of connections. Accordingly, mask magazine152of the coating section150is opposite to the side where the mask magazine107is located at the rotation module104. Opposite to the side where the mask magazine152is connected to the rotation module151, the second layer coating path and the compartments153to156are disposed. Accordingly, the substrate coming from the transport chamber108is disposed at the retainer of the movable support158and is rotated by 90° so that a linear movement path of the substrate or the substrate carrier is aligned with the direction towards the mask magazine152as well as the second coating path153to157. In this position of the movable support158which is perpendicular to the position shown inFIG. 2, a mask from the mask magazine152may be arranged at the substrate if the mask is necessary for the following second coating process. After arranging the mask at the substrate in the rotation module151, the substrate or substrate carrier is moved into the compartment153where the coating process for the second layer is starting. During movement of the substrate through the compartments153and154and the rotation module157as well as the compartments155and156a second layer is deposited at the substrate and all necessary treatments before and after depositing of the layer may be carried out.

After leaving the compartment156, the substrate is received in the retainer of the movable support158and the mask is removed from the substrate by the mask arranging device located in the rotation module151. The mask can be stored in the mask magazine152and can be used for the next substrate to be coated in the coating section150. If necessary, a mask cleaning device may be arranged at the mask magazine152, so that the mask can be cleaned if necessary, before re-using it for the next deposition process.

After removing of the mask, the movable support158is again rotated by 90° so that the substrate coated with a second layer can leave the rotation module151into the transport chamber180.

As mentioned before, a lot of coating sections150,160may be arranged one after the other in the coating apparatus100depending on the number of layers which have to be deposited. Due to the design of the apparatus100, it is also possible to only move the substrate through the rotation module151,161to the next coating section, if for specific substrates or generally for the process being carried out in the coating apparatus100, a third or fourth layer has not to be deposited. Therefore, the coating apparatus100is also very flexible with respect to the kind of use of the apparatus100.

The coating section160is identical to the coating section150. The only difference is the location of the inlet of the transport chamber180in the rotation module161compared to the inlet of the transport chamber108in the rotation module151. In order to save additional movements of the movable support, the place of connection to adjacent transport chambers at the different rotation modules may vary from one coating section to the other.

Since coating section160and150are almost identical, it is abstained from describing the same components having the same reference numerals added by10.

The last coating section140in the series of coating sections130,150,160of the coating apparatus100is identical to the second coating section40of the embodiment shown inFIG. 1, so that again with respect to the description of these components it is referred to the description of the embodiment ofFIG. 1. Again, the same components have the same reference numerals added by 100.

The different coating sections130,150,160as well as140can be operated independently so that e.g. the velocity of the substrate at which the substrate is moving through the coating path can be set optimally according to the requirements of the coating process. Only the rotation modules104,151,161and110have to be adapted to each other so as to allow a continuous flow of the substrates through the coating apparatus100. Thus, more flexibility with respect to optimization of each single coating process as well as an optimization of the through-put through the coating apparatus100is possible.

FIG. 3shows a third coating apparatus200similar to that one shown inFIG. 2. Accordingly, the same reference numerals added by100are used for designating the identical components of the embodiment shown inFIG. 3. An additional description is omitted.

The differences between the coating apparatus100and the coating apparatus200are explained as follows.

The coating apparatus200comprises a first coating section230, wherein the location of the mask magazine207and the first coating path205are exchanged. In the embodiment ofFIG. 3, the first coating path205is located opposite to the loading path202while the mask magazine207is located along the straight travel line of the substrate or the substrate carriers through the rotation modules204,291,261and210of the different coating sections230,290,260and300indicated by the broken line310. Accordingly, the sequence of movements of the movable support213has to be adapted for receiving and removing the substrate as well as arranging and removing a mask.

A further difference between the coating apparatus200and the coating apparatus100is given with respect to the second coating section290. Instead of a continuous coating a static coating is carried out. Accordingly, only one coating chamber293of a single-type coating chamber is disposed in coating section290.

Still another difference between the embodiment ofFIG. 3and that one ofFIG. 2is the connection between the coating sections230and290or260and300. While inFIG. 2transport chambers108,180,181are used for connecting the coating sections130,150,160and140buffer chambers285and286are arranged between rotation modules204and291as well as261and210. Buffer chambers285,286are designed such so as to allow storing of substrates or substrate carriers with substrates. Accordingly, it is possible to run the different coating sections more flexible and more independently from each other. Thus, it is possible to finish a coating process in a coating section, although a subsequent coating section is out of order.

Similar to the coating section290the coating section300is not equipped for a continuous coating, but for a wobble deposition of a layer. During wobble deposition the substrate is linearly moved back and forth to achieve homogeneity of the coating. Accordingly, the coating chamber301comprises a device for reciprocating motion of the substrate or substrate carrier.

Even though different coating sections have been described with respect to the embodiments ofFIG. 1 to 3, it is evident for a man skilled in the art that other coating processes or even other treatments may be performed in such sections and that accordingly the design of such sections may be different. Thus, although the coating sections refer by name only to coating processes, other processes like pre-treatment, after-treatment or finishing treatment processes may be carried out in these sections and the sections may be equipped accordingly.

Another type of a coating apparatus is shown inFIG. 4. The coating apparatus500comprises only a single central rotation type handling module501. Around the central rotation type handling module501a loading and unloading section502, a central mask storage unit503, a first deposition area504and a second deposition area505are located.

In front of the loading and unloading section502a substrate carrier storage506and a substrate handling unit507for placing the substrates on the substrate carriers of the substrate carrier storage506and for transporting the substrates together with a substrate carrier to the loading and unloading section502is provided. The loading and unloading section502comprises two twin-type vacuum chambers having the compartments508,509,510and511.

The compartments508and511are designed as lock-chambers, identical to the lock-chamber14of the embodiment ofFIG. 1. Accordingly, it is referred to the description of the embodiment ofFIG. 1. In addition, the loading and unloading section502comprises in the compartments509and510transport chambers like the transport chamber15of the embodiment ofFIG. 1.

The loading and unloading section502is connected to the vacuum chamber525of the rotation type handling module501and openings527and528are provided for in the compartments509and510as well as the chamber wall525of the rotation type handling module501to allow exchange of the substrates or the substrates together with the substrate carriers.

In the middle of the rotation module501a movable support520comprising a retainer520is arranged. The movable support may be designed similar to the embodiment of the movable support described inFIG. 6and rotates around the central axis of the rotation type handling module501.

The movable support520can be rotated around the central rotation axis so that the retainers521and522can be aligned with different openings526to532of the vacuum chamber of the rotation module501.

The loading and unloading section502may be designed such that the compartments508and509are only used for loading substrates while the compartments510and511are only used for unloading the substrates. However, in another embodiment the compartments508to511may be quipped in such a way that the substrates may be moved in both directions along the transport path so that the compartments508and509may not only be used for loading substrates but also for unloading them. The same applies for the compartments510and511.

After loading the substrate located on the substrate carrier through the compartments508and509into the coating apparatus on the retainer521the movable support520may be rotated by 90° so that the retainers521and522are aligned with the openings526,531and532of the vacuum chamber525. Accordingly, the retainer521may receive a mask from the central mask storage unit503through the opening526. After arrangement and alignment of the mask onto the substrate, the movable support522may again be rotated by 90° so that retainer521comprising the substrate with the attached mask is aligned to the opening530which is connecting the rotation type handling module501with the deposition area504.

The deposition area504comprises a continuous deposition path for continuously depositing several layers onto the substrate. The deposition area504comprises several twin type coating chambers comprising the compartments550,551,552,554,555and556. In the different compartments550to552and554to556of the deposition area504different treatments of the surface of the substrate may be carried out during continuous movement of the substrate through the compartments. For example, the compartments550,551,552may be equipped for the deposition of the hole transport layer as well as red and green organic light emitting layers. Similarly, the compartments554and556comprise equipment for depositing an organic blue light emitting layer as well as an electron transport layer. Accordingly, the substrates are moved through the compartments550,551,552,554,555and556in this order to receive the layers in the same order. Between the compartments552and554a rotation unit553for turning the substrate by 180° is provided. However, this rotation unit553does not comprise any tools for mask arrangement and/or alignment.

After leaving the compartment556the substrate is again received by the movable support520and the mask is removed from the substrate by the mask arranging590and aligning devices591(shown as block representations of the devices) provided in the rotation module501. The mask is again stored in the central mask storage unit503while the next mask for a subsequent deposition process in the deposition area505is arranged at the substrate. For attaching and removing the appropriate masks, the substrate is rotated by the movable support520to the appropriate positions. After attaching of a mask for the deposition process carried out in the deposition area505the substrate together with the mask is moved into the deposition area505. This deposition area505is according to the embodiment ofFIG. 4equipped with devices for LiF-treatment and aluminium deposition.

For this purpose the deposition area505comprises twin-type vacuum chambers comprising the compartments561and563as well as a single-type vacuum chamber562. While the LiF-treatment and the aluminium deposition are carried out in the vacuum chamber560, the vacuum chamber562is provided for change of the movement direction of the substrate without simultaneous deposition of a layer which might lead to an inhomogeneous layer. The transport compartment561is arranged for storing the substrate in order to wait until the rotation module501is ready for taking over the substrate. In addition, the compartment563also provides space for storing a substrate, if this is necessary in the processing sequence.

After the deposition of the layer in the deposition area505the mask is removed in the rotation module501and the finally coated substrate is unloaded through the loading and unloading section502.

The coating apparatus500is especially suitable for the deposition of organic light emitting diodes (OLED) for lighting devices, since for this purpose no different masks have to be used for depositing the red, green or blue layers of the OLED-structure. Accordingly, one continuous coating process can be formed in the deposition area504.

As indicated, the two coating paths provided for in the twin-type coating chambers of the deposition area504may be also used as a back-and-forth movement path so that the rotation unit553can be omitted. However, the order of the coating devices has to be adapted. If the deposition area504is used with two parallel back-and-forth deposition paths, the substrate is moved from the rotation module501through the compartments550,551and552and again back from552through551to550. After rotation of the substrate in the rotation module501the substrate may be moved through the compartments556,555and554and back again through555to556.

The back-and-forth continuous deposition similar to that described with respect to deposition area504is used in the embodiment of coating apparatus600shown inFIG. 5.

The embodiment ofFIG. 5also comprises only a single rotation type handling module601which is connected to a loading and unloading section602and a central mask storage unit603. These components as well as the substrate carrier storage606and the substrate handling unit607are identical to corresponding components of the coating apparatus500so that for the sake of simplicity a repeated description of these components is omitted. Instead of the deposition areas504and505, deposition areas604,604′ and604″ are provided for. All these deposition areas604,604′,604″ are designed as back-and-forth continuous coating paths being arranged parallel to each other in pairs of two in twin-type coating chambers. In all these deposition areas604,604′,604″ the substrate is moving in a linear movement from the rotation type handling module601to the end of the movement path in the deposition area and back on the same movement path in the opposite direction. Thus, the substrate is passing the deposition devices twice. In the deposition area604and the first back-and-forth continuous path610the hole transportation layer is deposited while in the parallel deposition path611the red emitting layer is deposited. Accordingly, the deposition area604′ comprises the third deposition path612for the green light emitting layer and the fourth deposition path613for the blue light emitting layer. Finally, the deposition area604′ comprises the sixth deposition path614for depositing of the electron transport layer and the seventh deposition path615for depositing the aluminium layer. Accordingly, the substrate is received by the movable support620of the rotation type handling module after every deposition step in each deposition path610to615in order to exchange the masks which are delivered and stored in the central mask storage unit603. Accordingly, this coating apparatus600may be used for producing OLED-displays for which for each layer different masks have to be applied.

FIG. 6shows an example for a movable support13as used in the rotation modules4,10,104,110,151,161,204,210,261,291,501and601. The movable support13comprises a frame401having a central plate structure408at the ends of which end plates402and403are disposed so as to form a double T structure in a cross section in a vertical direction. Parallel to the central plate structure two retainers are provided for. The retainers comprise guide and support elements in form of rails404,405and406,407arranged at opposing sides of the end plates402,403. The substrate or a substrate carrier can be pushed into the rails404,405or406,407along a movement direction parallel to a main surface of the central plate structure408. Thus, the substrate or substrate carrier can be arranged at the movable support by a linear movement.

In order to align the movable substrate with adjacent components like transport chambers, coating chambers and buffer chambers as described above, a rotation axis409extending through the center of the frame401and especially through the central plate structure is provided for. Thus, a substrate held by a retainer404,405or406,407in vertical or almost vertical alignment with a angle deviation of ±40°, especially ±20° to the vertical direction can be rotated around the vertical axis409.

Opposing the main surfaces of the central plate structure408an U-bend arch bracket410for mounting an arranging and alignment device for a mask is disposed. The U-bend arch bracket comprises two horizontally aligned rods411and413attached to the upper end plate402as well as the lower end plate403and a vertically aligned rod412connecting the ends of the rods411and413being distal to the end plates402and403. Thus, a handling and receiving space for the substrate as well as the masks used for deposition is defined.

At a mounting plate414fixed to the U-bend arch bracket410an arranging and alignment device415in form of a six axes parallel kinematic is mounted. The six axes parallel kinematic415comprises six independently actuated legs which connect the mounting plate414with a receiver platform for the mask. The lengths of the legs can be changed and due to gimbal mounting of the legs to the platform and to the mounting plate, the position and orientation of the platform can be varied so that a mask contained in the receiver platform416can be aligned with respect to a substrate positioned in a retainer of the movable support13.

Instead of a six axes parallel kinematic any other suitable device for arranging and removing of a mask on a substrate as well as aligning of the mask relative to the substrate may be used.

Although the present invention is described in detail with respect to the embodiments disclosed above, it is evident for a man skilled in the art that the invention is not restricted to these embodiments, but amendments like different combinations of features described with respect to the embodiments or omitting of features are possible without leaving the scope of the present invention which is defined according to the attached claims. In particular, the invention comprises all possible combinations of single features disclosed in this specification.