Abstract:
The invention concerns a transport device in an installation for the treatment of substrates with a succession of transport segments for the continuous in-line transport of the substrates along a transport line through several treatment sections, wherein a transfer means is provided for positioning one substrate each into a stationary treatment position. The object of the invention is to improve the functionality of a transport device of the generic method to guarantee reduced cycle times. The object is achieved with a transfer means having at least two matching, mobile combination segments, by means of which the substrate is positionable, wherein the combination segments in an alternating assignment to the transport line form a transport segment.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of U.S. Provisional Application No. 60/889,005 filed on Feb. 9, 2007, the entire disclosure of which is incorporated herein by reference in its entirety. 
     
    
     FIELD 
       [0002]    The invention concerns a transport device in an installation for the treatment of substrates with a succession of transport segments for the continuous in-line transport of the substrates along a transport line through several treatment sections, wherein a transfer means is provided for positioning each substrate into a stationary treatment position. 
       BACKGROUND 
       [0003]    Transport devices of this kind are to be found in installations for treating substrates in several successive treatment sections, for example in vacuum coating installations for the multiple coating of, for example, special glass. These involve an in-line arrangement, i.e. different coating sections connected in series, in which the substrates are transported by means of the transport device from one coating section into the next. In line with the configured sequence of the coating processes in the coating sections, all kinds of layer systems of several layers of varying material and thickness are applied by, for example, evaporation or sputtering onto the substrate. The variations in the layer systems lead to different retention times of the substrates in the individual coating sections. For example, different layer thicknesses at a continuous sputtering rate of the coating processes lead to coating times approximately proportional to the layer thickness. Thus, relative to the other layer thicknesses of the layer system, a double layer thickness requires twice the retention time for applying this layer thickness to the substrate in that coating section. In the case of an in-line configuration of the installation with sequential coating, however, the longest retention time of the substrates in one of the process stations determines the cycle time of the continuous substrate throughput rate through the coating installation. If a coating process step with an extraordinary long retention time compared with the other process steps of substrate treatment is necessary, this leads as a result to insufficient utilization of the coating sections having the shorter retention times and overall to low productivity of the coating installation. 
         [0004]    To solve this problem of the in-line configuration, a transport device is suggested in the prior art that has a transfer means for positioning one substrate each outside of the transport line in accordance with WO 2004/013375 A1. This installation con-figuration comprises a linear succession of several modules M for vacuum treating substrates with a transport device for transporting the substrates between the modules M and with a transfer means for separate positioning of a substrate within the module M, such that by means of the transfer means a substrate for special treatment is placed inside a module, while the transport device can transport another substrate past it for treatment in an adjacent module M. Each module of the transport device has one transport segment comprising a pairwise arrangement of belts  1 ,  2  driven by wheels  3 ,  4  ( FIG. 1  of the publication and associated description). On these belts  1 ,  2 , a substrate holder  9 , on which the substrate S is stored, is moved horizontally in the in-line transport direction on the lower plane B and transferred from module to module. For transfer of the linear motive force, notches  9   a  are provided in the substrate holder, which engage with projections  8  of the belts  1 ,  2  ( FIGS. 3 and 4  of the publication and associated description). The transfer means comprises a support frame  11  with a platform  10 , which by means of a driven lifting device  14 , and supported by the swivel-mounted levers  12  and  13 , may be vertically adjusted ( FIGS. 5 and 6  of the publication and associated description). This construction of the transfer means may be lowered between the belts  1 ,  2  and below the power-transmission plane of the belts  1 ,  2  into the lower part of the module, such that unhindered horizontal movement of the substrates S can take place by means of the belts ( FIGS. 3 and 4  of the publication). Once a substrate reaches the appropriate position in alignment with a treatment chamber C relative to the opening  16   b , the lifting device  14  is activated, which effects a vertical movement of the platform  10  together with the substrate holder  9  and the substrate S toward the up-per plane A, whereby the substrate holder  9  is detached from the belts  1 ,  2  ( FIGS. 5 and 6  of the publication). While the platform  10  with the substrate S is in the upper position A and substrate treatment is being performed in the treatment chamber C, another substrate S  1  can be transported linearly past substrate S from one module to the next for treatment in a downstream treatment chamber C. ( FIG. 1  of the publication). Thus, particularly time-consuming treatment steps on substrates can take place in parallel time, such that the cycle time of an in-line installation is no longer determined by this treatment process and is thereby reduced. In addition, different layer systems can be manufactured serially in an installation with the help of this bypass function. 
         [0005]    A disadvantage of the solution of the prior art, however, is that rerouting from horizontal in-line motion to vertical motion for positioning in the treatment position requires that the substrate be transferred by the transport device to the special transfer means. With the transfer of the substrate (including the substrate holder) to the transfer means, the form-fit connection for transmitting the force of the horizontal linear motion is released and conversely this connection has to be restored accurately again with the transfer of the substrate or the substrate holder to the transport device. This transfer of the substrate from one independent transport system into another independent transport system is regularly associated with deviations in positioning accuracy, irrespective of whether transport involves belts, rail transport or any other system, and therefore forms a permanent source of interference and error in the process cycle. In addition, the construction of the transfer means, which, for unhindered horizontal linear motion of the substrate, must be designed as an adaptation of the transport device, requires substantial space inside the vacuum treatment modules. 
       SUMMARY 
       [0006]    The task of the present invention is to further develop a transport device of the generic method such that its functionality for guaranteeing reduced cycle times with simple means is improved. 
         [0007]    This object is achieved in accordance with the invention by a transport device in accordance with claim  1 . 
         [0008]    The transport device in accordance with the invention has a transfer means with at least two matching, mobile combination segments, which in an alternating assignment to the transport line form a transport segment. One of the combination segments is arranged as a transport segment in the succession of transport segments along the transport line, while another combination segment is positioned outside of the transport line. The combination segment assigned to the transport segments effects, in the manner of a chain link, a link with the adjacent transport segments of the transport device, just like the links between the other transport segments. If a substrate or a substrate holder along the transport line is in connection with this combination segment, the transfer means causes an outfeed of this combination segment from the transport line for positioning of the substrate into the stationary treatment position, in which the substrate is preferably opposite a treatment tool. At the same time, the developing “gap” in the transport line is alternately canceled by another, yet identical combination segment of the transfer means. This combination segment joins the transport segments in place of the outfeed combination segment and again effects the previously described link with the adjacent transport segments of the transport device. The transport device can thus be continuously used, without restriction or interfering influences, in a simple manner for the continuous in-line transport of the substrates, such that a further substrate can be carried past the pre-ceding and outfed substrate, for example to a following treatment section. In the reverse procedure, with the outfeed of the incorporated combination segment from the transport line, the outfeed combination transport element moves back simultaneously into the gap that has become available in the transport segments, such that even a substrate positioned outside of the transport line can be further conveyed by the transport device without adverse transitions or interfering influences. The invention also concerns an installation, especially a vacuum coating installation. 
         [0009]    Advantageous embodiments of the transport device in accordance with the invention indicated in claim  1  are associated with the measures specified in the sub-claims. 
         [0010]    In a preferred embodiment, the combination segments are spaced apart from each other in parallel. Thus, the position of the combination segments can be adjusted or shifted at the same time by just one servo drive. 
         [0011]    If the combination segments are movable especially at right angles to the transport line, the positioning effort for alternate allocation of the combination segments is further minimized, whereby, depending upon the design of the transport device and the orientation of the transport line, preferably horizontal or vertical outfeed of the combination segments for the transport line may be suitable. Horizontal pushing or vertical lifting and lowering of the combination segments are realized by means of a correspondingly suitable and favorably designed rolling or gear wheel drive or a sliding gear or a belt drive, each of which is electrically, pneumatically or hydraulically operable. 
         [0012]    Preferably, one transfer means is provided in at least two successive treatment sections or assigned to at least two successive treatment tools. Thus, multiple protracted treatment processes in the installation may be conceived of and both serial and parallel treatment of substrates may be performed. The cycle time of the in-line installation is no longer determined by this long treatment process and is thereby reduced. Thus, the first substrate can be treated in the first treatment section or by the first treatment tool and the second substrate following in the transport direction can be transported past the first substrate to the next treatment section or to the next treatment tool and be treated in parallel. 
         [0013]    It is particularly advantageous if the combination segment and/or a substrate holder of the substrate assigned to the treatment tool is formed as a chamber partition. With outfeed of the combination segment including the chamber partition toward the treatment tool, it is possible to separably divide the treatment section into a process chamber and a transport chamber. Preferably by a connection of the formed chamber partition to sealing elements of the chamber wall, the substrate to be treated is sealed vacuum-tight inside the process chamber. The substrate transported during the stationary treatment of the substrate via the transport device through the treatment section is unaffected by this treatment process. Thus, different treatment processes can be performed independently of each other in the adjacent treatment sections. 
         [0014]    It is technologically favorable if a flat substrate with its treatment surface remains aligned parallel to the substrate transport plane during stationary treatment in one plane, i.e. is pushed merely parallel to the surface without change of orientation. In transport devices with transfer means in accordance with the invention, the treatment surface of the flat substrate is preferably aligned horizontally or essentially vertically. 
         [0015]    In a further expedient embodiment, the transport device has a rotary module with at least one transport segment, which can be assigned to the transport segments of two treatment sections. Likewise, it is possible to interconnect the transport segments of two treatment sections to at least one transport segment via a linearly oriented transport module. If the adjacent treatment sections each have a transfer means in accordance with the invention, one can in this way realize a treatment installation for static treatments, which can be operated both as an in-line installation and, similar to a cluster installation, with serial or parallel access to the individual treatment sections. This optional access to the individual treatment sections ensures that progressive movement of the substrates along the transport line is not blocked in any operating condition. Each substrate can be moved at any time in the transport direction to a free treatment section. With the transport device in accordance with the invention, higher throughput is possible in the case of certain treatment sequences, than for example in the case of the well-known cluster installations with central rotary module, which has a limited holding capacity for substrates and thus is overloaded when the treatment sections are fully populated. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a plan view of a vertical in-line coating installation in accordance with embodiments of the present invention; 
           [0017]      FIG. 2   a  is a side view of a transfer means in accordance with embodiments of the present invention; 
           [0018]      FIG. 2   b  is a side view of an alternative transfer means in accordance with embodiments of the present invention; 
           [0019]      FIG. 3  is a plan view of an extended in-line coating installation in accordance with embodiments of the present invention; 
           [0020]      FIG. 4   a  is a side view of a horizontal in-line coating installation in accordance with other embodiments of the present invention; 
           [0021]      FIG. 4   b  is a cross-sectional view of an in-line coating installation in accordance with other embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    The transport device in accordance with the invention is described in more detail in the following on the basis of two embodiments. The associated schematic drawings show in  FIG. 1  a plan view of a vertical in-line coating installation in accordance with an embodiment A with two coating sections and a transport device in accordance with the invention for essentially vertically aligned substrates,  FIG. 2   a  a side view of a transfer means, in accordance with the invention, of this transport device with two combination segments,  FIG. 2   b  a side view of an alternative embodiment of the transfer means in accordance with the invention,  FIG. 3  a plan view of an extended in-line coating installation in accordance with embodiment A with a rotary module arranged in between,  FIG. 4   a  a side view of a horizontal in-line coating installation in accordance with embodiment B with two coating sections and a transport device, in accordance with the invention, for horizon-tally aligned substrates,  FIG. 4   b  a cross-sectional view of an in-line coating installation in accordance with the embodiment B. 
         [0023]    The vertical in-line coating installation in accordance with the embodiment A in  FIG. 1  consists of two adjacent coating sections  1  and two abutting lock chambers  2 , wherein the coating sections  1  and the lock chambers  2  are separable from each other by vacuum-tight chamber valves  3 . The transport device in accordance with the invention passes through the lock chambers  2  and coating sections  1 , said de-vice formed from several transport segments  5  arranged in succession along a transport line  4 . The transport segments  5  in accordance with the embodiment A are formed for the transport of essentially vertically aligned flat substrates  8 , wherein particularly the transport segments  5  in  FIG. 1  are elements of a gas cushion transport device, in which the transport segments  5  each have an inclined or essentially vertically oriented substrate guide plate  6  with transport rolls  7  arranged at the base (readily evident from  FIG. 2   a ), with whose assistance the flat substrates  8  are transported standing at a slight inclination along the transport line  4  through the in-line coating installation. The substrate  8  floats on a gas cushion over the substrate guide plate  6  of the transport segment  5 . Each of coating sections  1  is provided with a transfer means  9  with two parallel, horizontally movable combination segments  10 , which are identical in their structure with the transport segments  5  along the transport line  4 .  FIG. 1  shows the respective transfer means  9  in the two possible positions I and II of the combination segments  10 , in each of which a combination segment  10  is assigned as a transport segment  5  to transport line  4 . In position I, the combination segment  10  outside the transport line  4  is facing a coating tool  11 . In position II, the combination segment  10  outside the transport line  4  is facing away from the coating tool  11 . 
         [0024]      FIG. 2   a  shows the transfer means  9  in a side view, from which may be seen the structure of the combination segments  10 , described previously and identical with the transport segments  5 , and their mode of movement for positional change. The combination segments  10 , spaced apart and parallel, are connected to a carrier plate  12 , which is mounted on transfer rolls  13 , which for example are driven by an electric motor or a pneumatic cylinder not shown. Carrier plate  12  and transfer rolls  13  are aligned with each other such that the combination segments  10  may be synchronously moved horizontally in a transfer direction  14  at right angles to the transport line  4  and so realize the positions I and II of the combination segments  10 . The alignment of the flat substrate  8  transported with the combination segment  10  along the transfer direction  14  is retained, in accordance with the alignment, during transport along the transport line  4 . Carrier plate  12  and transfer rolls  13  are arranged below the combination segments  10 , such that each combination segment  10  assigned to the transport line  4  incorporates itself unimpeded as a transport segment  5  into the other transport segments  5  along the transport line  4 . 
         [0025]      FIG. 2   b  shows an alternative embodiment of the transfer means  9 , which at the same time implies an alternative embodiment of the transport device as rail transport de-vice. The combination segments  10  identical with the transport segments  5  of this embodiment each consist of a rail segment  15  with bilaterally arranged driven transport rolls  16 . On one of the combination segments  10  is a substrate  8 , which is held by a flat carrier  17  (substrate holder) and is connected to a carrier car  19  that can move on rolls  18 . In the position in which this combination segment  10  forms a transport segment  5 , the carrier car  19 , driven by the transport rolls  16 , moves with the substrate  8  on the successive arrangement of rail segments  15  along the transport line  4 . Instead of the rail segments  15  with the transport rolls  16 , substrate transport may also take place by means of a rail system not shown, in which the rail segments  15  are formed as a linear motor on whose magnetic field the carrier car  19  floats. Moreover, instead of a carrier plate  12 ,  FIG. 2   b  shows one of the two U-shaped carrier rails  20  with which the transfer rolls  13  engage, as a result of which the combination segments  10  are well transported in their movement along the transfer direction  14 . 
         [0026]    The combination segment  10  of the transfer means  9  facing the coating tool  11  positions the substrate  8  into a coating position opposite the coating tool  11 , as is evident from position I of the combination segments  10  in  FIG. 1 . Thus the combination segments  10  function in a combined manner both as transport segments  5  and as “positioning elements” for positioning the substrate  8  in the treatment position. 
         [0027]    The substrate guide plate  6  of the combination segment  10  in accordance with  FIG. 2   a  or alternatively the flat carrier  17  in accordance with  FIG. 2   b  is designed as a chamber partition  21 , which, in position I of the combination segments  10 , functionally separates a process chamber  22  of the coating section  1  from a transport chamber  23 . The chamber partition  21  with sealing elements  24  corresponds to the chamber wall  25  of the coating section  1 , such that the process chamber  22  is separated vacuum-tight from the transport chamber  23  during coating of the substrate  8 . 
         [0028]      FIG. 3  shows an extended in-line coating installation in accordance with  FIG. 1  with four coating sections  1 , wherein two adjacent coating sections  1  are connected to each other by a rotary module  26 . The transport segments  5  of the rotary modules  26  connect alternately to the transport segments  5  of the coating sections  1  along the transport line  4 . The transport segment  5  of the rotary module  26  executes not only a rotating movement, but also a longitudinal movement along the transport line  4 , in order to be able to connect this transport segment  5  at a small distance to the respective transport segment  5  of the coating sections  1 . In this way, the in-line coating installation is arranged similarly to a cluster coating installation, with optional access to the coating sections  1  adjacent to the rotary module  26 . 
         [0029]      FIGS. 4   a  and  4   b  show a horizontal in-line coating installation in accordance with the embodiment B. Like the in-line coating installation in accordance with embodiment A, this consists of two adjacent coating sections  1 , wherein the adjacent lock chambers  2  and the vacuum-tight chamber valves  3  have been omitted for the purpose of simplifying the drawing. Through the coating sections  1  and the abutting lock chambers  2  runs the transport device in accordance with the invention, which in turn consists of a succession of several transport segments  5  along the transport line  4 . The transport segments  5  in a horizontal in-line coating installation are formed for the transport of horizontally aligned flat substrates  8 , wherein, for example, the transport segments  5  in  FIGS. 4   a  and  4   b  are roller segments  27  of a roller transport device, in which the flat substrates  8  are transported in the lying position over transport rolls  28  of the roller segments  27  and so are transported along the transport line  4  through the in-line coating installation. 
         [0030]    As is the case for the in-line coating installation in accordance with embodiment A, a transfer means  9  with two parallel combination segments  10  is also provided in the in-line coating installation in accordance with embodiment B, the structure of said segments being identical with the transport segments  5 , here especially with the roller segments  27 , along the transport line  4 .  FIG. 4   a  shows the respective transfer means  9  in the two possible positions I and II of the combination segments  10 , in each of which one combination segment  10  is assigned as a transport segment  5  to the transport line  4 . Grouping of the combination segments  10  occurs in a similar manner to the combination segments  10  of the in-line coating installation in accordance with the embodiment A, wherein, however, the combination segments  10  in accordance with the embodiment B are vertically movable by means of a lifting device  30  evident from  FIG. 4   b . To this end, the combination segments  10 , spaced apart and parallel to each other, are connected to guide profiles  29 , wherein the guide profiles  29  are a component of the lifting device  30 , which is driven via a transmission not shown in more detail by means of, for example, a servomotor or a pneumatic cylinder. Thus, the combination segments  10  are synchronously movable in a vertical transfer direction  31  into positions I or II, wherein, in position I, the horizontally aligned flat substrate  8  located on the combination segment  10  is transported toward the coating tool  11  arranged above the transport device for coating (also evident in  FIG. 4   b ). 
         [0031]    In accordance with the embodiment B in  FIGS. 4   a  and  4   b , tub-shaped chamber partitions  21  are provided, which are arranged underneath the transport rolls  28  of each combination segment  10 , wherein the chamber partition  21  arranged in each case in a plane between the pairs of combination segments  10  serves to functionally separate the process chamber  22  from the transport chamber  23  in position I. The peripheral edges of the tub-shaped chamber partition  21 , which partly comprise the transport rolls  28 , correspond with a sealing contact frame  32  of the chamber wall  25  of the coating section  1 , such that, in this embodiment too, the process chamber  22  is separated vacuum-tight from the transport chamber  23  during coating of the substrate  8 . 
         [0032]    Mechanism by which the in-line coating installation in accordance with the embodiments A and B functions: 
         [0033]    The substrates  8  are in-fed via chamber lock  1  and transported by means of the transport segments  5  along the transport line  4 . Once a substrate  8  reaches the first coating section  1  on its transport route, the substrate  8  is received by one of the combination segments  10  of the transfer means  9  there, which serves momentarily as transport segment  5 . By means of the transfer rolls  13  or by means of the lifting device  30 , the transfer means  9  moves both combination segments  10  synchronously in the horizontal transfer direction  14  or in the vertical transfer direction  31  from the position II towards the coating tool  11 , until the transfer means  9  has positioned the substrate  8  in the treatment position opposite the coating tool  11  (position I of the combination segments  10 ). The resultant gap in the succession of transport segments  5  is closed at the same time by the parallel combination segment  10 , which thus in turn forms a transport segment  5  along the transport line  4 . The following substrate  8 , transported along the transport line  4 , can now pass the first coating section  1  unhindered and without interference, in order to reach the adjacent coating section  1  past the preceding substrate  8 . There, the substrate  8  is received by the combination segment  10  of the transfer means  9  there, which is in position II of the combination segments  10  and subsequently can also be positioned in the treatment position (position I of the combination segments  10 ). During coating of the substrate  8  in the first coating section  1 , the process chamber  22  is separated from the transport chamber  23  by means of the chamber partition  21 , such that the passing substrate  8  is not affected by the coating process in the first coating section  1 . Thus, parallel and also serial coating of substrates  8  in the adjacent coating sections  1  are possible. In particular, protracted coating processes on the substrates  8  can be operated in a parallel, time-saving manner. Transfer of the substrate  8  to the corresponding transport systems of the in-line transport and of the transfer transport for the purpose of positioning the substrate into the stationary treatment position and back again is effected advantageously without interference-prone translation of the substrate  8  into the different transport systems. 
       TRANSPORT DEVICE IN AN INSTALLATION FOR THE TREATMENT OF SUBSTRATES LIST OF TERMS 
       [0000]    
       
           1  Treatment, coating section 
           2  Lock chamber 
           3  Vacuum-tight chamber valves 
           4  Transport line 
           5  Transport segment 
           6  Substrate guide plate 
           7  Transport roll of the substrate guide plate 
           8  Substrate 
           9  Transfer means 
           10  Combination segment 
           11  Treatment, coating tool 
           12  Carrier plate 
           13  Transfer roll 
           14  Horizontal transfer direction 
           15  Rail segment 
           16  Transport roll of the rail segment 
           17  Substrate holder, carrier 
           18  Carrier car roll 
           19  Carrier car 
           20  Carrier rail 
           21  Chamber partition 
           22  Process chamber 
           23  Transport chamber 
           24  Sealing element 
           25  Chamber wall of the coating section 
           26  Rotary module 
           27  Roller segment 
           28  Transport roll of the roll segment 
           29  Guide profile 
           30  Lifting device 
           31  Vertical transfer direction 
           32  Sealing contact frame 
         I Position I of the combination segments 
         II Position II of the combination segment