Patent Application
20070009652
Aspects of the present invention relate to a device and a process for the production of substrates provided with organic electroluminescent materials (OLED).
In the field of technical actuating elements and entertainment electronics, flat panels and displays are gaining increasingly in importance. An interesting realization of such flat panels is afforded by so-called OLED displays or screens in which organic electroluminescent materials between electrodes are deposited on a flat, transparent substrate in order that, by means of actuation via the electrodes, light emissions which can be used for producing an image may be generated.
Vacuum-coating processes, generally in so-called cluster tools, are used for the production of such OLED screens. There are usually arranged about a center various modules in which different coating steps are performed, with a centrally arranged robot inserting the substrates to be coated into the corresponding modules, removing them again and transporting them to the next module. While such a technology offers certain advantages with regard to purity requirements and process conditions in the individual modules, it is not meaningful for economic mass production of corresponding OLED screens.
For this reason, there are already proposals in the prior art for so-called in-line machines, which facilitate a continuous sequence of the various necessary coating steps. Examples here are JP 2003332052 A, WO 03/090260 A 2 and WO 03/043067 A 1.
JP 2003332052 A proposes an annular arrangement of different coating stations, for example for the deposition of red-, green- and blue-emitting electroluminescent materials, with a separate cleaning station for the masks necessary for structuring the coatings proposed outside the ring at an outfeed station. However, such a machine configuration requires a high outlay for the separate transport path of the cleaned masks to the infeed station as well as regards the separate arrangement of the cleaning stations.
WO 03/090260 A 2 A describes a device for depositing multi-layer coatings on substrates, with the substrates guided several times through the coating machine on an essentially linear track in order that the different layers may be deposited. Although a continuous in-line machine is realised thereby, such a machine has disadvantages due to the repeated travelling of the substrate through the coating machine.
WO 03/043067 A 1 describes a device for the production of organic electroluminescent, light-emitting devices for mass production in which the substrate to be coated is arranged on carrier, which, for example, is guided along a track arrangement through a vacuum-coating machine and in which the carriers with the substrate can dip into adjacent coating chambers in order that a wide variety of coating processes may be performed.
Here, too, the outlay for lowering the substrates into the individual coating chambers is very high, both temporally during the coating process and from the design aspect.
Additionally, all processes, such as substrate cleaning, mask arrangement for structuring, and cleaning of the masks as well as the coatings in the various chambers are performed in succession.
At least one aspect of the invention is directed to create a coating machine or a device for especially continuous production of a substrate provided with organic electroluminescent materials (OLED), especially OLED displays, screens, panels or other OLED lighting elements, in which the disadvantages of the prior art are avoided and especially a simple and favourable possibility for mass production of OLED elements is provided, combined with a small space requirement and with allowance for high quality standards for the OLED products. In at least one version the corresponding device is easy to manufacture and the process easy to operate.
One aspect of the invention is characterised by the fact that the coating machine or device is constructed on the dual-chamber principle, i.e. that the entire vacuum space of the vacuum-coating machine is preferably divided into two parts along its longitudinal axis, with a first part of the vacuum space used to transport the carriers loaded with the substrates to be coated through the coating machine from the loading to the unloading station and the other, second part of the machine serving to return and clean the substrate carriers and especially the masks required for structuring. This has the advantage that a very compact machine with genuine continuous operation can be realized as a so-called in-line machine, in which stockpiling of both carriers and masks is largely avoided by guiding carriers and/or masks in endless loops, and the throughput and efficiency are substantially increased.
Furthermore, by virtue of the dual-chamber principle, simple construction and simple operation, especially also for the generation of the vacuum, are possible, with especially the dual chambers capable of being formed as all-round modules, such that corresponding process tools and other devices can be arranged in the corresponding dual-chamber modules, as required. This greatly facilitates conversion as well. Moreover, such a construction facilitates uninterrupted transport of substrates or carriers and/or masks for microstructuring the coatings in the vacuum. As a result, contamination of the carriers or masks by the environment is avoided.
Further, where necessary, lock chambers and/or lock devices and isolating devices can be provided between the individual chambers or chamber modules in order that specific areas may be sealed off to avoid contamination or in the event of partial venting of the machine.
Aside from the endless loop for transporting the carriers, which, with the first section of the transport device, extends along the first part of the vacuum space in the direction of substrate transport and, with the oppositely directed, second section of the transport device, i.e. in the carrier-return-transport direction, extends in the second part of the vacuum room or the vacuum dual chambers, preferably several second endless loops for transporting masks are advantageously and additionally preferably provided which serve the purpose of structuring or microstructuring the coatings. The corresponding transport arrangements of the second endless loops for transporting the masks have a first section also in that part of the vacuum space in which substrate transport from the infeed area to the outfeed area takes place, and have a second section for the return transport in the second part of the vacuum space.
In addition, preferably at least one transport branch may be provided in which the transport device for the substrate carrier and/or the transport arrangement for the masks is not formed as a continuous loop, but instead parallel transport sections in the same and/or opposite direction are provided in the dual chambers. This can be advantageous in the infeed and outfeed areas especially, since, in this way, both parts of the vacuum dual chambers can be used for transporting the substrates on the substrate carriers to and away from the mask-placement station, and as a result the efficiency can be greatly enhanced. Correspondingly, more substrates can be diverted in quick succession into the coating process, a fact which further increases the efficiency of the machine.
Preferably, the transport devices for the carriers and the transport arrangements for the masks use partly the same transport means and handling devices, such that at least some transport occurs jointly. Especially, the substrate carriers serve preferably also as mask carriers for the at least partial return transport of the masks.
Preferably, the changeover from the first section of the transport device or the transport arrangement to the second section of the transport device or transport arrangements occurs in the endless loops and vice versa in the substrate-loading stations and/or substrate-unloading stations in which the substrates are arranged at the carriers or are removed from these and/or in the mask-placement stations and/or mask-removal stations at which the masks are assigned to the substrates or are arranged on or removed again from these.
In a preferred embodiment, a rotation module is provided which, in one station, performs not only mask exchange for two adjacent coating areas but also effects transfer of the masks from the coating section to the cleaning section and vice versa, with corresponding mask-placement and/or removal stations and/or mask-alignment stations and holding elements for the masks being provided at the rotation module.
The rotation module comprises a rotary mechanism with a rotary table on which are provided two pick-ups with transfer positions for substrate carriers from both the first section and the second section of the transport device, whereby, through rotation of the rotary table through 180 degrees, the pick-ups can be moved into the transfer positions of the respective other transport section and, on rotation through 90 degrees, into transfer positions for transfer to an adjacently arranged mask and/or substrate-carrier exchange area. First, the masks are removed in the mask-exchange areas from the substrate carriers, then the substrate carriers are assigned to the respective other waiting mask and, after placement, moved further along the transport system.
Preferably, masks and/or substrate-carrier magazines can be provided along the transport route for the substrate carriers and/or masks in order that substrate carriers and/or masks may be exchanged or in order that, given the different duration of handling processes, optimisation of throughput and the efficiency of the device may be effected. Further, the magazines can also be used to load the machine. Preferably, such intermediate magazines, which may have one or especially several storage places, are assigned to the transfer devices, the mask-placement and/or mask-removal stations and/or the rotation modules. Through use of substrate-carrier or mask-transfer units, which offer corresponding rotary and/or translatory movements for the respective handling possibilities, the corresponding substrate carriers and/or masks can be simply diverted into and out of the transport process again and moreover exchanged between magazine units, for example several magazines arranged together.
Like the mask- and/or substrate-carrier magazines, additional mask- and/or substrate-carrier cleaning stations can also be provided in side-branches outside the actual transport route, such that, through brief outfeed from the actual transport route, cleaning of the masks and/or the substrate carriers can be effected. This can take place especially in addition to cleaning, which can occur during return transport in the second section or in the second part of the vacuum chamber.
The endless loops can each be realised by a single continuously operating transport device or by a plurality of handling devices and transport means, in which, for example, the substrates and/or carriers or the masks are transferred from one device to the other. Correspondingly, transport of masks and/or substrate carriers can take place completely continuously, i.e. without stopping, or discontinuously with intermediate stopping and/or any combination thereof. Occasional return transport into individual stations is thus possible and conceivable as well. Thus, coating or general treatment of the substrates can also take place dynamically, i.e. during transport, or statically, in which the substrate is not moved. Consequently, there are three basic possibilities for types of coating or treatment that can be combined with each other, namely continuous dynamic, timed dynamic or static.
In at least one embodiment of a device, it is possible, given corresponding processes for production of OLED elements, during return transport to directly clean the masks or shadow masks required for structuring of the coatings and to avoid or reduce mask stockpiling as well as to minimise the number of necessary masks overall.
Further advantages, characteristics and features of the present invention are apparent from the following details description of two embodiments using the enclosed drawings. The drawings show in purely schematic form:
Additionally, a separation can be effected by providing locks or isolating elements 20, which facilitate separation or isolation of individual areas of the vacuum space. Preferably, the vacuum space is constructed of similar modules, which, in line with their use as mask-placement and removal stations or substrate-loading and unloading stations, coating stations and the like, are equipped in different ways.
Device 1 has an overall linear construction, with a substrate-infeed device 5 provided at one end and a substrate-outfeed device 6 at the opposite end. Apart from the linear construction, it is naturally possible to have a different construction with corresponding curves or transport around a corner. By means of the substrate-infeed device 5 and the substrate-outfeed device 6, the substrate to be coated can be diverted into or out of the vacuum space of device 1 from ambient conditions or a different vacuum-treatment machine.
The substrate-infeed device 5 is followed, after a lock or isolating device by a substrate-loading station 7, in which the substrate to be coated is arranged on a carrier 40 (see
Alternatively, the substrate-loading station can also be provided in the substrate-infeed device, such that handling of the substrate during positioning on the substrate carrier can take place simply in air and not in the vacuum. In that event, the substrate-infeed device would be followed only by a transfer module, in which the returned substrate carrier from part 4 is transferred into part 3 and subsequently transported into the substrate-infeed device for loading. The outfeed area could also be arranged correspondingly.
After the substrate-loading station 7 comes mask-placement station 8, in which a mask (shadow mask) (see
The mask-placement station 8 also comprises a transfer device with the aid of which a mask from part 4 of the vacuum space can be transferred to part 3 of the vacuum space, with the mask simultaneously also changing transport direction from the return transport direction into a substrate-transport direction. Given a corresponding configuration with handling and holding devices substrate-loading station 7 and the mask-placement station 8 can also be combined in a single station.
Mask-placement station 8 is followed by a plurality of vacuum dual chambers 2, which are fitted out for the corresponding coating processes in or at part 3.
In the embodiment shown in
After the carrier with the substrate thereon and the mask have travelled through coating areas 9 to 11, it passes into the connecting mask-removal station 13, where the mask is removed from the substrate. Mask-removal station 13, too, has a transfer device, by means of which the removed mask is transferred to part 4 of the vacuum space where it is transported back to the mask-placement station 8 in the opposite direction to substrate transport, which, in the embodiment of
Meanwhile, the carrier with the substrate moves into the mask-placement station 14, which is arranged after the mask-removal station 13, and in which, as in mask-placement station 8, a new mask is in turn applied to the substrate in order that an appropriately adjusted mask may be provided for subsequent electrode application by thermal evaporation.
In mask-placement station 14, just as in mask-placement station 8, the corresponding mask is transferred from part 4 of the vacuum space to part 3 of the vacuum space, with the mask changing its direction of transport. Moreover, just as in mask-placement station 8, the mask is aligned in mask-placement station 14, such that structuring of the coating material to be applied occurs precisely in those areas in which the structures are necessary.
The vacuum dual chambers 2 in area 15 after mask-placement station 14 are equipped such that the electrode material can be thermally evaporated onto the substrate. Naturally, other evaporation processes are also usable.
After travelling through coating station 15, the substrate on the carrier and the mask arranged thereon pass into mask-removal station 17, where the mask is in turn removed from the substrate and transferred to part 4 of the vacuum space, such that the mask can be transported back, in the opposite direction to substrate transport, and cleaned in cleaning station 16 so that it is immediately available again in the mask-placement station.
In the following substrate-loading station 18 for the carrier, the substrate is removed from the carrier and transported to the substrate-outfeed station 6, while the carrier is transported to part 4 of the vacuum space and moved back to the substrate-loading station 7.
During return transport of the carrier in the preferred embodiment shown, mask and carrier are transported jointly, with, in this case, the carrier in mask-removal station 17 picking up the mask for the return transport and correspondingly transferring it again in mask-placement station 14. In the same manner, during return transport in part 4 of the vacuum space in mask-removal station 13, the carrier picks up the mask from the previous coating process and transports it to mask-pick-up station 8. However, provision of separate means of transport for carriers and masks is also conceivable for the return transport.
Overall, in the embodiment of
The other mask of the coating process of coating station 15 moves from mask-placement station 14 in part 3 of the vacuum space via coating station 15 to mask-removal station 17, where it also changes direction of transport and is transported via cleaning station 16 in part 4 back to mask-placement station 14.
These endless loops, expressed in terms of the objects moved, that is the endless loops from the viewpoint of the carrier or the masks, can be formed by a plurality of handling and transfer devices. However it is also conceivable that a single continuous conveying device is provided especially for the movement of the carrier.
In the same manner, diverse manifold devices for picking up and moving the masks, carriers, substrates etc. are conceivable for substrate-loading and unloading stations 7 and 18 as well as mask-placement and removal stations 8 and 14 on one hand and 13 and 17 on the other.
A conceivable transfer device, for example, for substrate-loading and unloading stations 7 and 18 as well as mask-placement and removal stations 8, 13, 14 and 17, is a simple rotary mechanism in which carrier plate 70 rotates or pivots about an axis 80, more precisely through 180 degrees, such that carrier 70 points once with its corresponding side towards part 3 of the vacuum space and, after rotation through 180 degrees, the next time towards part 4 of the vacuum space. Given a vertical alignment of the substrate, that is an alignment perpendicular to the plane of the diagram of
In this way, it is also particularly simple to realise a combination of substrate-loading and unloading stations 7, 18 and mask-placement and removal stations 8, 13, 14, 17, 18, for example of mask-removal station 13 and mask-placement station 14, since only corresponding intermediate holding devices need to be provided for the parts to be received and placed. A corresponding rotation module is described below in connection with
Coating stations 121, 122 and 123 together form coating area 110 for the electroluminescent material. Additionally, coating areas 109 and 111, corresponding to coating areas 9 and 11 of the embodiment in
Device 100, too, along with its vacuum space is divided into two along its longitudinal axis, into part 103 and part 104, with, in part 103 or correspondingly at parts 103 of vacuum dual chambers 102 provided there, the corresponding substrate-treatment and coating stations 109, 110, 111, 115 and 119 provided, while cleaning stations 112, 130, 131, 132, 133 and 116 are assigned to or are arranged at or in part(s) 104.
Like the lock or isolating device 20 of the embodiment in
The overall result is that device 100 has a-construction with a substrate-infeed station 105, a substrate-loading station 107, a mask-placement station 108 and an endless loop for the carrier with transport means, which moves the carrier with applied substrate and changing masks first past plasma-activation station 119, then past coating station 109 and then past further coating stations 121, 122, 123,and 111 as well as 115 to finally separate the substrate from the carrier in the substrate-unloading station 118 and to issue the substrate in substrate-outfeed station 106 or make it available to subsequent treatment devices. The carrier, without substrate and again with changing masks, is then moved back in the second part 104 of the vacuum space to the substrate-loading station 107, passing cleaning stations 116, 133, 132, 131, 130 and 112 in that order.
Apart from this first endless loop, device 106 has two endless loops for the corresponding masks, with the first mask in mask-placement station 108 being arranged and aligned on the substrate or the carrier relative to the substrate in order that the substrate may be protected and only exposed in the corresponding areas of previously defined areas as it is passing through plasma-activation station 119 and coating station 109. This mask is removed in mask-removal station 113 from the substrate or the carrier and transported back through mask-cleaning station 112 to mask-placement station 108 in vacuum partial space 104. If plasma activation of the entire surface of the substrate is desired, mask-placement and alignment station 108 can also be provided between plasma-activation station 119 and coating station 109. Instead of plasma activation, other processing techniques for cleaning and/or activation of the surface, especially surface-activation techniques, are conceivable, such as UV, ozone treatment or ion bombardment.
The second endless loop of the second kind for transporting a corresponding mask is provided for coating area 121, with the mask placed and adjusted in mask-placement station 114, removed from the substrate or carrier in mask-removal station 124 and cleaned in cleaning station 130.
The third, fourth, fifth and sixth endless loops of the second kind are assigned to coating stations 122, 123, 111 and 115, with, in each of the corresponding mask-placement stations 125, 127, 129 and 135, the masks for the subsequent coating process placed and aligned on the substrate or carrier, while the corresponding masks are removed again in mask-removal stations 126, 128, 134 and 117 after the respective coating stations.
This mode of operation is illustrated more clearly by the schematic diagrams of
As is especially evident from
Given use of corresponding handling means permitting short-term intermediate storage of at least one of the corresponding masks, a combination of mask-placement and mask-removal stations in a single station is conceivable, as shown in
In the example of
A mask-cleaning station can be attached at the side of rotary area 262 opposite mask-exchange area 261, for example, when the rotation module in the infeed area is used.
Except for rotation module 260, which replaces the mask-placement and removal stations of
In addition, device 200 from
Substrate-infeed device 270 has a robot 273, which transfers the substrates to the substrate carriers in a transfer module 274. The transfer module is designed such that the substrate carriers in it can be rotated about an axis perpendicular to the image plane and can execute linear movements, such that the substrate carrier can be taken from transport sections 278 and 279 of vacuum dual chambers 202 and transferred to these.
A special feature of substrate-infeed device 270 consists in the fact that both transport sections 278 and 279 in vacuum dual chamber 202 can serve to feed substrates to the two mask-placement stations 271. This means that, in parallel transport sections 278 and 279, both unidirectional and counter-directional transport are possible, in contrast to the anti-parallel transport in the coating areas.
In addition, not only is feeding of substrates to mask-placement stations 271 possible in transport sections 278 and 279 of substrate-feeding device 270, but also transport of the substrate carriers in the direction of transfer module 274. Correspondingly, substrate-cleaning stations 272 are also provided, which serve to clean the substrate carriers.
This type of arrangement of substrate feed effects a marked increase in efficiency and throughput, since more substrates can thus be sent on their way through the coating areas. Especially, substrate-infeed device 270 with turning module 275 can work at a very much higher cycle frequency than the transport device in the area of the coating areas.
Further, in the area of rotation module 260, two substrate-carrier magazines 281 and 282 are provided which are connected to each other by a substrate-carrier-transfer module 283 and to rotation module 260. This storage unit 280 thus facilitates intermediate buffering of the substrate carriers to facilitate optimisation of the throughput of substrates through the coating machine. Moreover, there is the possibility of exchanging defective substrate carriers. Additionally, the storage unit can serve to load the machine with substrate carriers. As for the rest, rotation module 260 functions as described with reference to
Like the substrate-infeed area, substrate-outfeed area 290 has a turning module 275, mask-removal stations and/or intermediate storage 276 and a substrate-carrier-handling or transfer module 274 that interacts with a robot 273. Substrate-transfer module 274 and robot 273 are arranged in a so-called glove box with inert atmosphere.
In the case of substrate-outfeed device 290, too, the two transport sections of vacuum dual chambers 202, at which corresponding mask-removal or storage units 276 are arranged, are traversable in both directions for the substrate carriers, such that here, too, rapid outfeed of the substrates is possible.
Especially, the transport speed in the individual areas and sections can be different in order that optimum use of the entire device may be facilitated. Thus, for example, the speed in the transport branches of substrate-infeed device 270 and substrate-outfeed device 290 can be different from transport speeds in coating areas 209 to 211 and 215a and 215b. Additionally, the transport speeds can also differ in the coating areas, and also in the sections, i.e. in part 203 of the vacuum dual chamber and the other part 204 of the vacuum dual chamber. Thus, the transport speed in the coating part can be different from the transport speed in the area of return transport. This facilitates optimised utilisation of the entire device.
In detail, device 200 of
Thus, in the embodiment shown, the substrate introduced into part 203 of the vacuum chambers travels through coating areas 209, 210a, 210b, 210c and 211, where, for example, a hole injection layer, a hole transport layer, a red emitter layer, a green emitter layer, a blue emitter layer, a hole blocking layer and an electron injection layer are applied in that order. Then, the substrate with the mask arranged thereon is picked up in rotation module 260, where the mask is removed in mask-removal station 265, and is then transported back again in part 204 of the vacuum chamber, while the coating substrate in mask-placement station 264 takes a new mask, which is required for the subsequent coating process in coating chambers 215a and 215b.
Connected to mask-exchange area 261 of rotation module 260 is a substrate-carrier-transfer module 283, which serves two substrate-carrier magazines 281 and 282. Substrate carriers can be exchanged here accordingly.
Subsequently, the substrate with the new mask, still in part 203 of the vacuum chamber, is guided further through coating stations 215a and 215b, where LiF evaporation and then aluminium evaporation and corresponding deposition take place. Thereafter, the substrates on the substrate carriers with the masks are transferred to a turning module 275 of the substrate-outfeed device 290, from where they pass into mask-removal station 276 and the substrate carrier is unloaded in substrate-transfer unit 274, 273. This takes place in inert gas atmosphere in a so-called glove box.
Substrate infeed with substrate-infeed device 305, following transfer by robot 373 as well as substrate outfeed with substrate-outfeed device 306 and transfer to robot 373 proceed similarly as in the embodiment of
Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated various alterations, modifications, and improvements, will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.
| Number | Date | Country | Kind |
|---|---|---|---|
| 05008669.3 | Apr 2005 | EP | regional |
| 06112340.2 | Apr 2006 | EP | regional |
This application relates to U.S. patent application Ser. No. ______ entitled PROCESS AND DEVICE FOR POSITIONING THE MASK (Attorney Docket No. A2022-700010), by Dieter Manz, filed on even date herewith, and U.S. patent application Ser. No. ______ entitled MAGNETIC MASK HOLDER (Attorney Docket No. A2022-700110), by Dieter Manz, filed on even date herewith. Both of these related applications are incorporated herein by reference.
