Title of Invention	"A LOCK CHAMBER DEVICE FOR A VACUUM TREATMENT PLANT"
Abstract	Lock chamber device for a vacuum treatment plant with at least two lock chambers (EK1, EK2) which are sequentially arranged within the vacuum treatment plant for carrying out a double-stage or a multi-stage pressure equalization process, and whereas both lock chambers (EK1, EK2) are separated from each other by a valve flap (VK2) and whereas a first pump set (P1) for evacuating a first lock chamber, as well as a second pump set (P2, P3) for evacuating a second lock chamber, are provided characterized in that said first pump set (P1) is connected with both the first (EK1) as well as with the second (EK2) sequentially arranged lock chamber by means of lockable conduits (1, 2), so that the first pump set may evacuate either the first or the second or both lock chambers.

Title of Invention

"A LOCK CHAMBER DEVICE FOR A VACUUM TREATMENT PLANT"

Abstract

Lock chamber device for a vacuum treatment plant with at least two lock chambers (EK1, EK2) which are sequentially arranged within the vacuum treatment plant for carrying out a double-stage or a multi-stage pressure equalization process, and whereas both lock chambers (EK1, EK2) are separated from each other by a valve flap (VK2) and whereas a first pump set (P1) for evacuating a first lock chamber, as well as a second pump set (P2, P3) for evacuating a second lock chamber, are provided characterized in that said first pump set (P1) is connected with both the first (EK1) as well as with the second (EK2) sequentially arranged lock chamber by means of lockable conduits (1, 2), so that the first pump set may evacuate either the first or the second or both lock chambers.

Full Text	The present invention relates to a lock chamber device for a vacuum treatment plant. The present invention refers to a lock chamber device according to the preamble of claim 1 and 14, respectively and to a process for operating a multistage lock chamber de¬vice. Glass panels are being coated, for example, in vacuum coating plants, under high-vacuum conditions, at pressures within the range of 5 x 10-4 hPa until 1x10-2 hPa, espe¬cially within the range of 3 x 10-3 hPa for sputtering processes. In order to increase plant productivity figures and to avoid the requirement of having to evacuate the entire installa¬tion for each substrate and, especially, the high-vacuum section, load and unload locks are being used for the substrates. In order to improve the material flux rate and increase productivity figures, in modern in-line coating plants, separate load and unload lock chambers are being used. A simple so-called 3-chamber coating unit consists of a load lock, in which the substrate is being pumped from atmospheric pressure to an adequate transition pressure of f.ex. p = 5E-2 hPa, of a sequential vacuum coating section (process chamber) and an unload lock, in which, by means of ventilation, said substrate is again being adjusted to the atmospheric pressure level. The task of lock chambers in evacuating as quickly as possible to a sufficient and lowest possible transition pressure to the process range. While ventilation may take place in a few seconds, without utilizing pumps, for evacuating purposes, a certain vacuum pump stand must be connected to the lock chamber. A co-decisive factor for productivity and concurrent economical utilization of an inline coating unit, is the so-called cycle- i.e. station time, i.e. the time which has to be used per batch of substrate before the next batch of substrate may be introduced into the unit, or the average processing time per substrate batch under continuous operating conditions. In order to achieve, for example, a cycle time of 2 min, the lock chamber must be in condition to deliver within t According to the known relation: (Formula Removed) with t =•= pump time v « volume s =» pumping capacity P0 - start pressure (atmospheric pressure) Pi => target pressure (transfer pressure, lock reversing pressure), it becomes evident that there arc clearly two possibilities to reduce the pump time and consequently also the cycle time. > Volume reduction of lock chamber > Increase of pumping capacity coupled to the lock chamber. Since both possibilities have technical and economical limits, in these in-line coating plants with high productivity rates and corresponding reduced cycle time, measures have been taken to subdivide the evacuation-/ventilation process into two or more lock chambers For the inlet side, this implies, for example, that within a primary load lock, evacuation takes place from atmospheric pressure until an intermediate pressure of, for example, 10 hPa, while in a secondary lock chamber, this action takes place from the intermediate pressure (i.e. equalization pressure) until the transfer pressure, for example 5E-2 hPa. In such a 5-chamber unit (2 load locks, 2 unload locks, 1 process chamber), load and unload action is being split up between two chambers and, thus, takes place in two steps, being distributed in two cycles. Thus, for example, in architectural glass panel coating units, with a lock chamber volume of approximately 2 m3 until 5 m3, it was possible to reduce the cycle time from approximately 60 s until 90 s, until approximately 40 s until 50 s. In order to attain still shorter cycle times, for example t erational range, i.e. for example, assigning to the first load lock chamber (1) an atmosphere-fnendly pump stand for the pressure range of 1000 hPa until, for example, 10 hPa, while for the second load lock chamber (2), a multistage, for example a 3-stage, Roots pump stand for the pressure range of 10 hPa until 2E-2 hPa was assigned. Document US 4,504,194 discloses an apparatus for high speed vacuum pumping of an air lock. For this purpose an expansion tank with a volume larger than the volume of the air lock is provided. The expansion tank is evacuated by a vacuum pump connected to the expansion tank. However, the apparatus is only suitable for lock chambers having a small volume, and for processes where the processing period is long compared with the evacuation period Using the apparatus in units with large volume lock chambers, e.g. m architectural glass panel coating units, is not feasible-It is, thus, a task of the present invention to improve the operational efficiency of a lock chamber unit for vacuum coating plants, especially of the existing 5-charnber, or 7-chamber systems respectively, being thus improved with two up to three load and unload lock chambers, as well as with a process chamber, and especially achieving shorter evacuation times and thus shorter cycle times for the lock chamber unit In view of the improved operational efficiency, also the costs for the pump sets of the lock chambers should be reduced, i.e. lock chambers should be saved, which, again, should offer a cost and space advantage. Another aspect of the present invention consists in attaining lower transition pressures at given cycle and pump times. This task is solved by a lock chamber unit with the features of claims 1 or 14, as well as with a process for operating a lock chamber unit with the features of claim 25 or 28 Advantageous embodiments are an object of the dependent claims. Based on a first aspect, the present invention is based on the recognition that the operational capacity of the pump sets and, thus, the time for evacuation of lock chambers may be improved i.e. reduced when, according to the corresponding requirements, said pump sets are variably adapted to the individual load lock chambers, since a highest possible use of the pump sets is being envisaged. It is thus possible, by utilizing existing pressure pumps, to achieve an increase of the effective pumping capacity i.e. a shorter transfer of the substrate from one load lock chamber to another chamber. According to the invention, it is no longer rigidly considered that a pump unit is available for a certain load lock chamber, but the basic idea of the invention consists in that different pump sets may be adequately grouped, united or regrouped reciprocally during the inlet process, in order to attain an ideal pump capacity, i.e. to render feasible an earliest possible transfer from one lock chamber to another chamber, at transfer pressures still at a high level. Accordingly, a first pump unit, primarily designed for a primary lock chamber, will not only be used for this chamber, but also for a second lock chamber, and only corresponding connections will have to be provided from the pump unit to the first lock chamber and to the second lock chamber According to the requirements and stage of the loading process, it is, thus, possible to offer the pumping capacity, i.e. absorbing capacity, of the first pump unit either to the first load lock chamber or to the second load lock chamber or to both chambers simultaneously- Additionally, this first pump set is not only assigned directly or indirectly to the second load lock chamber, but the first pump set, according to a preferred alternate embodiment, will be sequentially added to said load lock chamber on an additional i.e. alternate basis, as a pre-pumpmg stage for a second pump set, primarily designed for evacuation of the sprnnd lock chamber It is thus possible to further expand the possibilities of utilization of the first pump set, providing a more efficient pumping capacity distribution. According to another preferred embodiment of the present invention, a third pump set is being foreseen, which, as a sequentially added pumping stage for the second pump set, especially in the area of the lock chamber with lower pressures, reinforces the second pump set, especially when the first pump set is no longer available as a pre-pumpmg stage, since it should be primarily used for the first lock chamber Alternately to the above, according to another embodiment, a third pump set may be assigned as a common pre-pumping stage for the first pump set and the second pump set, and the third pump set may be utilized either as a pre-pumpmg stage for the first pump set or for the second pump set or jointly for both. It is also thus insured that the third pump -similar to the first pump set - may offer to the load lock chambers an altered pumping capacity, especially during the loading process. Accordingly, or the pumping capacity obtained will thus be utilized to reduce the evacuation time or lower transfer pressure rates will become feasible According to another advantageous embodiment of the present invention, in the case of pumps of a pump set adjacently connected in a parallel direction, a corresponding by-pass may be foreseen, so that by activating/liberating said by-pass and adequate separation of the remaining connecting conduits, this pump is being sequentially connected to the prior parallel connected pumps, in order to produce a multistage pumping stand. This offers the advantage that according to the required pumping capacity, i.e. pressure conditions, by simple regrouping of the pumps, the pumping capacity may be adjusted according to requirements. For example, in the event that the first pump set is available as a pre-pumping stage for the second pump set, the corresponding pump may be operated parallel with the other pumps in the second pump set, while upon deactivation of the first pump set, as pre-pumping stage, the pump with the by pass will be sequentially connected to the other pumps of the second pump set, in order to compound a multistage pumping stand with these sets. According to another advantageous embodiment, in the case of pumps connected m an adjacent parallel position, especially pumps of the second pump set for the second lock chamber, in a position parallel to said pumps, a differential pressure bypass lid may be integrated, so that the parallel pump sets, especially the second pump set, may be automatically operated according to the prevailing pressure conditions also in the case of high intake pressures. Due to the action of the differential bypass lid K2, the outlet section of the parallel integrated pumps is being connected, i.e. short-circuited, with the aspiration section, for example over the second lock chamber, in order to provide a maximum differential pressure. The maximum compression rate of the parallel integrated pumps and, consequently, also their capability of mechanical, i.e. electrical, acceptance, are being limited, so that these pumps may be used already at considerably higher intake pressures than without a differential pressure bypass lid As a consequence, such parallel integrated pumps, such as, for example, Roots pumps, may accompany the pumping action also at relatively high pressure rates, offering their pumping capacity in a prior pumping evacuation phase. It is, thus, possible to waive complex pumps for the second pump set, such as, for example, Roots pumps, cooled before the inlet phase, which may control a high admissible differential pressure of, for example, > 800 hPa. Additionally, it is, thus, also possible to let the second pump set permanently connected with the second lock chamber, without the need of closing corresponding valves in the conduits leading to the lock chamber. This also provides a better utilization rate of the pumps of the second pump set, i.e. an altogether more simple design of the pump set. Instead of only one parallel integrated differential bypass lid, each pump may have its own differential pressure bypass hd, or, else, it is possible to use pumps with integrated (differential pressure) bypass lids. Evidently, the different pump sets may encompass one or various parallel reciprocally integrated, single or multistage, vacuum pumps, such as, for example, oil-sealed or dry-compressing vacuum pumps, especially rotary vane pumps, rotary piston pumps, rotary plunger pumps, roots vacuum booster, dry running pumps especially axial pumps, Roots pumps, especially pre-admittance-cooled Roots pumps, etc. Due to the variable embodiment of the pumping capacity, it is especially also possible to completely waive oil-sealed pump sets, utilizing only dry-compressing vacuum pumps, such as, for example, axial pumps. According to a second aspect, an acceleration of the transfer process is attained by providing buffer devices, which offer a buffer volume, which, for example, is being evacuated during occasions when the pumping capacity of certain pump sets is not required for the immediate evacuation process, or when direct outlet action is not yet feasible The absorption capacity, i.e. the pumping capacity, is thus being stored in the buffer set and, at the right moment, it is being offered to the lock chambers by a sudden pressure equalization, for the purpose of evacuation, i.e. pressure reduction of lock chambers. The sudden pressure equalization enables a considerably fast evacuation within fractions of seconds, i.e. practically on a "zero time" basis. Preferentially, for each lock chamber a specific buffer device may be provided with a corresponding buffer volume, and additionally to these external buffer devices, the lock chambers specifically also may act as buffers, when the lock chamber, closest to the vacuum area, is previously being evacuated and subsequently, with a preceding lock chamber, providing a pressure equalization for a sudden pressure reduction. The external buffer devices may be equipped with separate pump sets, however it is especially convenient to utilize existing pump sets, already provided for the lock chambers, separately or additionally to separate pump sets of said buffer devices An optimal utilization of said lock chamber pump sets may thus be assured. It is evident for the specialist that the measures described may be materialized both on the load, as well as on the unload side of the lock. Other advantages, features and characteristics of the present invention will become clear based on the subsequent, detailed description of preferred embodiments, based on the attached drawings The drawings indicate in a merely schematic form: Fig. 1 - a schematic representation of the inlet section of a glass coating unit, with corresponding pump set; Fig. 2 - another embodiment of a lock chamber with an inlet section, comparable to representation of Fig 1, Fig. 3 - a third embodiment of an inlet section with a representation similar to Fig. 1; and Fig. 4 - another embodiment of a lock chamber. Fig 1 features a schematic representation of the mlet section of a vacuum treatment plant, in. the present case a glass coating plant, with two inlet chambers EK1 and EK2, as well as a transfer chamber TK and a sputtering chamber SKI. The sputtering chamber SKI and the transfer chamber TK feature plurality of high-vacuum pumps, in order to adjust high-vacuum conditions for the coating area. The inlet chambers EK1 and EK2 are separated against the outer environment by means of valve flap VK1, and against said transfer chamber TK by means of valve flap VK3 Amongst said devices, separation is being produced by valve flap VK2. A valve VF)ut for ventilating said inlet chamber EK1 is being provided at said inlet chamber EK1. Additionally, at inlet chamber EK1, a first pump set PI is provided with five parallel integrated rotary vane pumps, connected with inlet chamber EK1 over conduit 1 and valve VI. Furthermore, pump set PI is connected with inlet chamber EK2 through conduit 2 and valve V2. Also, through conduit 3, which may be closed through valve V5, pump set PI is connected with the second pump set P2, P3, formed by parallel integrated Roots pumps P2 andP3. Roots pumps P2 and P3 of the second pumps set are interconnected through conduit 5 at the outlet side, and conduit 5 may be locked over valve V7. Pumps P2 and P3 are also connected with said inlet chamber EK2 through conduits 4 and valves V3 and V4 therein integrated. Additionally, the third pump set P4 is being provided based on a double-stage Roots pump stand with a Roots pump and subsequently integrated rotary vane pump, connected through conduit 6, featuring valve V6, with the second pump set and here especially with conduit 5. Furthermore, at inlet chamber EK2, high-vacuum pumps are provided, reciprocally connected in parallel projection and which over valves Vhl through Vh3, may be coupled with inlet chamber 2. The inlet process in such a lock chamber unit takes place in such a fashion that initially valve lid VK.1 of the first inlet chamber EK1 is being opened and substrate is being transported into the said inlet chamber EK1. Subsequently, valve lid VK1 will be closed and valve VI will be opened towards pump stage PI, so that inlet chamber EK1 may be evacuated. Subsequently, valves V3, V4 and V5 are being closed and valve V2, as well as valve lid VK2, are being opened. This takes place, for example, with a pressure of 200 hPa. Simultaneously, the substrate is now being moved from the first inlet chamber EK1 towards the second inlet chamber EKZ Once an adequate pressure level has been attained, for example of 80 hPa, valves V5 and V3 will be opened and valves VI and V2 will be closed. Simultaneously, or with reduced delay, valves V4 and V7 will be opened Also, valve V6 will now be opened, this valve V6, however, being provided on an optional basis, having to be present only with a certain type of the pump stand P4. If, for example, the third pump set P4 is being composed by a forepump and a Roots pump with a bypass conduit, said optional valve V6 may be waived, since, in this case, the third pump set P4 may be activated and continuously operated at atmospheric or very high intake pressures, for example of 100 hPa up to 300 hPa Subsequently, valves VI and valve lid VK2 are being closed, so that inlet chamber EK1 may again be ventilated and valve lid VK1 may be opened, in order to accept the next substrate in inlet chamber EKL Also, valve V5 is now being closed, so that the first pump set PI no longer operates as a forepump stand for the second pump set P2, P3, i.e. parallel in relation to the third pump set P4, but not only the third pump set P4, as a retaining pump stand, is subsequently connected to the second pump set P2, P3, while due to opening of valve VI, the first pump set will again be utilized for evacuating the first inlet chamber EK1. In the second inlet chamber EK2, the optional high-vacuum valves Vhl until Vh3 may now be opened, m order to regulate said inlet chamber EK2 at high-vacuum conditions With an approximate pressure stand of 0,3 hPa, valves V3 and V4 may be closed and after the corresponding vacuum conditions have been attained, for example with a pressure of 2 x 10 ~3 hPa, valve lid VK3 may be opened, in order to transfer the substrate into the processing area (transfer chamber) It is important during this phase that the above described procedures take place inside, i.e. with the two inlet chambers partly in a simultaneous fashion, so that a lowest possible cycle time is being reached. Due to the fact the first pump set PI is connected not only with inlet chamber EK1, but also with the second inlet chamber EK2, the first pump set PI may be utilized for a longer period of time, in order to contribute towards a shorter inlet, i.e. admission, time It is an advantage of the unit described, i.e. of said procedure, that valve lid VK2 between inlet chamber EK1 and inlet chamber EK2 cannot be opened only at acceptance pressure of the Roots pumps P2 and P3 of the second pump set, i.e. at approximately 15 hPa, but this may take place already at higher pressures, in the range of 100 hPa through 200 hPa, especially 150 hPa Pumping times will, thus, be cut down inside inlet chamber EK1 by approximately one third, or pump set PI could be reduced by a third, relative to the pumping capacity Additionally, it is advantageous that the first pump set PI may be used with pumps P2 and P3, through valve V5, as a forepump stand of the second pump set, so that the second pump set with pumps P2 and P3 may be used at much higher pressures. A utilization rate of approximately 100 hPa, instead 10 hPa, will now become feasible. Especially, opening and closing times of the different valves, especially opening of V5, V7, V3 and V4, as well as closing of V2, may be reciprocally synchronized in such a fashion, that no interruption of the pumping capacity is caused and commuting times of cycle times are, thus, not being negatively influenced. The third pump set P4 is designed to form with the second pump set P2, P3, a multistage pump stand, until the necessary transfer pressure, i.e. activation pressure, for the optional high-vacuum pumps PHI until PIHD has been attained- Also, the third pump set P4 is designed to reinforce the second pump set P2, P3, when the first pump set PI is being required for evacuating said inlet chamber EK1, thus no longer being available as a forepump stand for the second pump set P2, P3. In the alternative embodiment of Fig. 3, which largely corresponds to the embodiment of Fig. 1, and, consequently, will henceforth only be described regarding the differences, with the second pump set, additionally to the Roots pumps P2 and P3, a third Roots pump P5 is parallel integrated, connected with inlet chamber EK2 over an additional conduit 14 and valve 10 therein disposed Additionally, in a parallel sense in relation to the third pump P5, a conduit 8 is foreseen, disposed between the inlet chamber conduit 14 and conduit 5, connecting the outlet side of pumps P2, P3 and P5, and again a valve Vll is integrated in conduit 8. Conduit 8 discharges between valve V10 and pump P5 into conduit 14. Furthermore, a valve V12 is integrated between the inlet of conduit 8 in conduit 5 and inlet of conduit 6 in conduit 5. This bypass set to pump P5, by closing valve V10, as well as valve V12 and opening of valve Vll, renders it possible to integrate pump P5 sequentially to Roots pumps P2 and P3, so that pump P5, with the third pump set P4 - here formed by a single stage pump set based on a rotary vane pump - forms a multistage Roots pump stand. Consequently, at the moment in which the first pump set PI no longer is available as sequentially integrated pumping stage for the second pump set - since the first pump set PI again has to evacuate inlet chamber EK1 - it is feasible to attain a potential, multistage pump set for inlet chamber EK2 by regrouping pump P5, i.e sequential integration of pump P5 to pumps P2 and P3. Accordingly, before valve V5 or V7 is being closed, valves V10 and V12 are being closed and valve Vll will be opened, in order to sequentially integrate pump P5 with pumps P2 and P3 Except for the above, the sequence corresponds to the inlet process in the inlet area of Fig-1. The advantage of this variant, however, is seen in the fact that dunng the discharge, i.e. outlet phase with the second pump set P2, P3, P5, by closing valves V10 and V12 and opening valve Vll, a three-stage Root pump stand may be formed with the second and third pump set P4 as a forepump unit. The third stage with Roots pumps P2 and P3 may be doubled or halved by opening/closing V7, or may be split up between the first pump set PI and the third pump set P4, respectively. In the embodiment of Fig. 2, the first pump set is formed by two parallel integrated, singled stage and pre-admittance cooled Roots pumps, connected over conduit 1 and valve VI with inlet chamber EK1 and over conduit 2 and valve V2, are connected with mlet chamber EK2 (The pre-admittancc gas cooling is not shown). The second pump set consists of the double-stage parallel Roots pumps P2 and P3, which again are connected with mlet chamber EK2 over conduits 4 and corresponding valves V3 and V4. At the discharge side of the first pump set PI and of the second pump set P2, P3, a third pump set P4a, P4b of parallel integrated, single stage dry-running pumps for example m the form of axial pumps, is foreseen, which over conduit 6 is connected with the second pump set P2, P3, i.e. with their joint conduit 5, i.e. over conduit 7, with the first pump set PI. In conduit 6, there is valve V6 and in conduit 7, valve V8 is foreseen, so that the corresponding connections may be separated Additionally, in the connecting conduit between the parallel integrated axial pumps P4a and P4b, a valve V9 is foreseen. With the embodiment of Fig. 2, both inlet chamber EK1, as well as inlet chamber EK2, may be discharged over multistage pumping stands, and especially due to this disposition, oil-scaled forepumps may be waived, and alternately, in an especially advantageous form, exclusively dry-compressing pumps may be used-Admission of a substrate into the vacuum treatment plant of Fig. 2, takes place in such a fashion that initially valve lid VK1 of the first inlet chamber EK1 is being opened, and substrate is being transported into inlet chamber EK1. Subsequently, valve hd VK1 is closed and valve VI to the first pump set PI is opened, and the gas transported at high pressure levels, for example 500 until 1000 hPa, contingent upon the forepump level of the third pump set P4, is being evacuated mto the atmosphere over discharge lid Kl. As of an acceptance pressure Pu of, for example, 300 hPa, valve V8, i.e. V8 and V9, are being opened, so that a multistage pump set is being provided for discharging said inlet chamber EK1 Valves V3 and V4 are now being closed, while valve V2 and valve lid VK2 between inlet chamber EK1 and inlet chamber EK2 are being opened. The substrate is now being transported from the first inlet chamber EK1 into the second mlet chamber EK2. Subsequently, valves V6, V3 and V4 are being opened and eventually valves V8 and V9 are being closed. Then, valve lid VK2 and valve VI are being again closed, to that the admittance chamber, i.e inlet chamber EK1, is being ventilated and valve lid VKl may be opened, in order that the next substrate may be introduced into mlet chamber EK1 Subsequently, valves V8 and V2 are being closed and VI is opened to evacuate the first inlet chamber EK1. The high-vacuum pumps PHI until PHS - according to the operation of the first example according to Fig 1 - may be connected with inlet chamber EK2 over valves Vhl until Vh3, so that valves V3 and V4 may subsequently be closed When inlet chamber EK2 corresponds to vacuum conditions of sputtering chamber 1, valve lid VK3 will be opened and substrate will be introduced into the processing area. Also here, evidently, the processes m both load lock chambers EK1 and EK2 partly take place simultaneously. The advantage of this disposition consists in that the first pump set PI, and also the third pump set P4, may be utilised nearly on a 100% basis, i.e practically over the entire mlet, i.e. admission cycle. Additionally, also here chamber valve VKL2 may be opened already at higher pressure levels, for example 100 until 400 hPa, especially 250 hPa, which, compared to an opening at approximately 15 hPa, corresponding to the acceptance pressure of Roots pumps P2 and P3, corresponds to an evidently shorter pumping time for discharging mlet chamber EK1, i.e. renders feasible a more compact construction of the corresponding pump stand Due to the variable conditions of utilization of a third pump set P4 as a forepump stand, both of the first pump set PI as well as of the second pump stand P2, P3, also for inlet chamber EK1 and inlet chamber EK2, a multistage pump stand is being provided, for van-able utilization. Especially, with all embodiments shown, the pumping capacity, i.e. the absorption capacity, may thus accompany the substrate at the inlet side or generally along the direction of evacuation from atmosphere to vacuum, i.e. according to the local requirements of pumping capacity, so that this results in a considerable capacity increase and time reduction. Fig 4 shows another embodiment of a lock chamber unit according to the invention, which is largely coincident with Fig 3 A first difference is to be found in the fact that the second pump set, with the parallel integrated pumps P2, P3 and P5, features no bypass 8 parallel to pump P5, such as m Fig.3, but, parallel to conduits 4, with which pumps P2, P3 and P5 are connected to the second mlet chamber EK2, a differential pressure bypass lid K2 is provided, connected with the second inlet chamber EK2 over conduit 9 and valve V17. By means of this disposition, it is possible to couple the parallel integrated Roots pumps P2, P3 and P5 with relatively high intake pressure, m order to be able to utilize - according to the adjusted differential pressure - already with high intake pressures, a portion of their absorption capacity for rapid evacuation Due to a connection of the outlet side of pumps P2, P3 and P5 with the absorption side, over the second inlet chamber EK2, bypass lid K2 foresees that pumps P2, P3 and P5 only have to overcome a differential pressure which may be adjusted at bypass lid K2. For this purpose, for example, said bypass lid may consist of a spring-loaded or weight-loaded valve, which opens towards the direction of the chamber at the occasion of a determined overpressure at the evacuation side of Roots pumps P2, P3 and P5. Valves V3, V4 and V10 may thus be opened, or remain open, at higher absorption pressures and/or the utilization of pre-adrmttance cooled roots pumps, which also could be used at higher pressures, may be waived, so that it is possible to reduce the costs for the second pump set, providing, simultaneously, a higher pumping capacity. Evidently, instead of a differential pressure bypass K2, vanous differential pressure lids could be provided, for example for each pump P2, P3 or P5, or it would be possible to utilize Roots pumps with integrated bypass lids. The disposition of said bypass lid K2 offers the additional advantage that valves VI7, V3, V4 and VI0 during their operation may remain permanently open, i.e. they do not have to be forcibly closed in each cycle, especially when the high-vacuum pumps PHI through PHJ are waived. The operation is thus also accordingly simplified. A second difference of the embodiment of Fig. 4, as compared with embodiment of Fig. 3, consists in that the parallel integrated vacuum pumps of the first pump set PI may be coupled over a conduit 10 and valves V13 and V15 therein foreseen, as a sequential stage to the third pump set P4 or parallel to other pumps P97 over valve V16, and P10, over V13. By closing valve V5 and opening valves V6, V13, V15 and eventually V9, it is thus possible to form, dunng the evacuation stage, a multistage pumping level with the first pump set PI, the fourth pump set P4 and the second pump set P2, P3 and P5. Thus, starting at the two-stage pumping level, without interrupting the pumping capacity, an almost perfect transition to a three-stage pump level may take place, or, in general terms, of a n-stage pumpmg level, a n+1 -stage pumping level may be formed. It is evident that, consequently, pump P9 with valve V16 only could be provided on an optional basis. Another essential difference of embodiment of Fig. 4, as compared to the preceding embodiments, consists in that additionally it features an outer buffer unit EB1, which through valvt V14 and conduit 8, as well as conduit 1, is connected with the first inlet chamber EK1. Buffer unit EB1 offers a buffering volume, which may be absorbed through the optionally foreseen fifth pump set P6 or through the first pump set PI. With the thus evacuated buffer volume, after opening valves VI and V14, pressure inside the first inlet chamber EK1 may be suddenly reduced In this form, it is possible to utilize pumping capacity, i.e. absorption capacity, in periods of time, in which pumping capacity i.e. absorption capacity for direct evacuation of inlet chambers EK1 and EK2 is not being required or when the additional integration of the fifth pump set P6 and inlet chamber EK1 should not be advantageous, due to pressure conditions. This pumping capacity, i.e. absorption capacity, as it were, is being stored in buffer unit EB1 and afterwards, in case of need, is being offered to the first inlet chamber EK1. In a similar fashion, also the second inlet chamber EK2 may act as an internal buffer unit, when by opening valves VI and V2, a pressure equalization is being made between inlet chambers EK1 and EK2, so that also here the pressure declines suddenly. Especially in the case of a reciprocally adjusted combination of a pressure equalization between the first inlet chamber EK1 and buffer unit EB1 and subsequent pressure equalization between the first inlet chamber EK1 and the second inlet chamber EK2, it is possible to attain two stages of a quick pressure reduction, and also here the absorption capacity relative to the second inlet chamber EK2 may be utilized during a large penod of time of the transfer process Additionally, a second outer buffer unit EB2 may optionally be provided with corresponding optionally foreseen additional sixth pump set P7, by means of which a pressure equalization between the second inlet chamber 2 and the second buffer unit EB2 also provides a sudden pressure reduction. Instead of the sixth pump set P7, the buffer volume of the second buffer unit EB2 may also be evacuated through the second (P2, P3, P5), third (P4) and/or other pump sets already provided for the second inlet chamber EK2, such as, for example, P9 In the embodiment of Fig. 4, it is also indicated that high-vacuum pumps PHI through PH3 may be abandoned in all embodiments, and are therefore only optional when over the absorption capacity for the second inlet chamber EK2 a sufficient vacuum may be obtained Valves V3, V4, VI0 and V17 arc designed to be capable of separating the second inlet chamber EK2 from the pump stand and render possible an independent ventilation of the chamber, or of the pump stand, respectively. If it should be considered that this is not required, these valves may also be waived. Valves V3, V4, V10 and V17 are, however, needed in any case, when the second buffer unit EB2 is to be evacuated over the second pump set P2, P3, P5, since then a separation from the second inlet chamber EK2 will be required. However, if the second buffer unit EB2 is to be evacuated only through the sixth pump set P7, the second buffer unit EB2 could also be directly united with the second inlet chamber EK2bymeansofV18. In an embodiment according to Fig. 4, the transfer process takes place in the following way Initially, valve lid VK1 of the first inlet chamber EK1 is being opened and the substrate is being transported into the first inlet chamber EKl Subsequently, valve hd VK1 is closed and valve VI is opened towards pump stand PI. Valve V14 is open during this process and valves V2, V5 and VI3 or V15 are closed. Due to the pressure equalization with the evacuated buffer volume of the first buffer unit EB1, pressure in the first inlet chamber EK1 is suddenly reduced from atmospheric pressure to approximately 400 hPa. VI4 is now being closed and V2 js being opened, so that a second sequential pressure equalization takes place, precisely between the first inlet chamber EK1 and the second evacuated inlet chamber EK2. With approximately identical chamber volumes of the first and second inlet chambers EK1 and EK2, pressure in both chambers is suddenly regulated to approximately 200 hPa. Valve lid VK2 is now being opened and substrate is moved from the first inlet chamber EK1 into the second inlet chamber EK2. During this process, valve V5 is being opened and valves VI and V2 are being closed. Simultaneously, or with reduced delay, valves V6 and V15 and, eventually, V13 are being opened and valve V5 is being closed, so that there is no longer a bypass towards the third pump set P4, now prevailing a multistage pumping level with pumping stages from the first pump set PI, second pump set P2, P3, P5 and third pump set P4 Valve lid VK2 is now being closed and the first inlet chamber EK1 is ventilated over valve VFlut Subsequently, valve lid VK1 may be opened and the next substrate may be transported into the first inlet chamber EK1. The optionally provided high-vacuum pumps PHI through PHJ may now be connected with the second inlet chamber EK2, by means of opening valves VH1 through VH3. fa this case, valves V3, V4, V10 and V17 are closed. If no high-vacuum pumps are foreseen on the second inlet chamber EK2, these valves may if necessary remain continuously open during operations. Valve lid VK3 may now be opened and substrate may be transferred towards the process area, i.e. into transfer chamber TK. Valves V13 and VI5 are being closed and valve V14 will be opened, so that the first pump set may evacuate the buffer volume of the first buffer unit EB1 If the fifth pump set P6 is foreseen, the buffer volume of the first buffer unit EB1 may be evacuated jointly through the first pump set PI and the fifth pump set P6. The inlet process will then be reinitiated. If with the lock chamber arrangement of Fig. 4, the second outer buffer unit EB2 is provided, then valve V18 will be opened for pressure equalization between the second inlet chamber EK2 and the previously evacuated buffer volume of the second buffer unit EB2, after substrate has reached the second inlet chamber EK2 and after valve lid VK.2 has been closed. Pressure in the second inlet chamber EK2 may thus be suddenly reduced from approximately 30 hPA to 10 hPa. During transportation of substrate from the second inlet chamber EK2 into transfer chamber TK, valves V3, V4, V10 and V17 are being closed, in order to utilize the second pump set with pumps P2, P3 and P5 for evacuating buffer volume of the second buffer unit EB2. With the solution now proposed, according to embodiment of Fig 4, based on the buffer solutions, it is possible to produce the pressure reduction through a double-stage pressure equalization in the first lock chamber within quite short time periods, i.e. periods much smaller than a second, so as to be able to transfer immediately the substrate into the second lock chamber With a second buffer unit, this effect may also be utilized for the second lock chamber EK2. The process now presented in the inlet area, in a correspondingly analog fashion may also be utilized for the outlet, i.e. unload area, without the requirement of a closer description ainrp the anpriali may Hcrtakft the eorresnondme adaotation in a simple fashion. WE CLAIM: 1. Lock chamber device for a vacuum treatment plant with at least two lock chambers (EK1, EK2) which are sequentially arranged within the vacuum treatment plant for carrying out a double-stage or a multi-stage pressure equalization process, and whereas both lock chambers (EK1, EK2) are separated from each other by a valve flap (VK2) and whereas a first pump set (PI) for evacuating a first lock chamber, as well as a second pump set (P2, P3) for evacuating a second lock chamber, are provided characterized in that; said first pump set (PI) is connected with both the first (EK1) as well as with the second (EK2) sequentially arranged lock chamber by means of lockable conduits (1, 2), so that the first pump set may evacuate either the first or the second or both lock chambers. 2. Lock chamber device as claimed in claim 1, wherein to the first (PI) and the second (P2) pump set is connected a third pump set (P4 a, b) through correspondingly lockable conduits (6, 7), so that the third pump set may be sequentially integrated either into the first or the second or into both pump sets. 3. Lock chamber device as claimed in claim 1, wherein said first pump set (PI) is connected with the second pump set (P2, P3) by means of lockable conduits (3), so that the first pump set may be sequentially integrated with the second pump set. 4. Lock chamber device as claimed in one of the preceding claims, wherein the pump sets (PI, P2, P3, P4) encompass various parallel and/or sequentially integrated pumps. 5. Lock chamber device as claimed in claim 4, wherein said pump sets encompass oil-sealed and/or dry-compressing vacuum pumps, especially rotary vane pumps, rotary piston pumps, rotary plunger pumps, vacuum roots booster, dry- running pumps, especially axial pumps, Roots pumps, especially pre-admittance cooled Roots pumps. 6. Lock chamber device as claimed in claim 5, wherein said pumps parallel integrated in one pump set, feature a lockable bypass (8), through which at least one of the pumps may be connected sequentially relative to the other pump, in order to compose a multistage pumping stand. 7. Lock chamber device as claimed in claim 1, wherein said lock chamber (EK1, EK2) adjacent to the process chamber, one or various high-vacuum pumps (PHI, PH2, PH3) are provided by means of lockable conduits. 8. Lock chamber device as claimed in claims 1 to 7, wherein parallel to one, especially to the second pump set, a bypass lid (K), commanded by differential pressure, is integrated, which, in the event of high pressure applied on the evacuation side, especially in the second lock chamber (EK2), represents a bypass from the outlet side towards the inlet side of pump sets (P2, P3, P5), so that a maximum differential, critical pressure level, preferably adjustable, being applied to the parallel integrated pump set is not being exceeded and the pumping capacity of the pump set is continuously being utilized on a pressure dependent basis. 9. Lock chamber device as claimed in one of the claims 1 or 3 or 5, wherein the first pump set (PI), with one or different parallel integrated, single-or multistage, especially atmosphere-friendly vacuum pumps, through a first conduit (1), featuring a first valve (1), is connected with the first lock chamber (EKI), and though a second conduit, featuring a second valve, is connected with the second lock chamber (EK2) and through a third conduit (3), featuring a third valve (V5), is connected with the second pump set (P2, P3), with the second pump set featuring one or various parallel integrated, single-or multistage vacuum pumps, which, over a fourth or other conduits (4), featuring a fourth valve (V3, V4), are connected with the second lock chamber (EK2) and the parallel integrated pumps of the second pump set are reciprocally interconnected through fifth conduits (5) with a fifth valve (V7). 10. Lock chamber device as claimed in claim 9, wherein at the outlet side of the second pump set (P2, P3), especially at the fifth conduit (5), uniting pumps (P2, P3) of the second pump set, the third pump set (P4) is coupled with one or various parallel integrated, single-or multistage vacuum pumps through a sixth conduit (6) connected to a preferentially provided sixth valve (V6). 11. Lock chamber device as claimed in claim 9 or 10, wherein said first pump set encompasses rotary vane pumps, said second pump set encompasses Roots pumps and the third pump set encompasses double-stage Root pump stands or a single-stage pump stand with rotary vane pumps. 12. Lock chamber device as claimed in one of the claims 9 through 11, wherein between the fourth (14) and the fifth (5) conduit, a seventh conduit (8) is provided with a seventh valve (Vll), so that a parallel integrated pump (P5) of the second pump set may be integrated sequentially relative to the other pumps. 13. Lock chamber device as claimed in claim 1, wherein the first lock chamber (EK1) is provided with a buffer unit (EB1) which may be connected through lockable conduits (1, 8). 14. Lock chamber device as claimed in claim 13, wherein the buffer unit (EB1) features a fifth pump set (P6), which evacuates the buffer volume. 15. Lock chamber device as claimed in claim 1, wherein the first pump set (PI) is connected with the buffer unit (EB1). 16. Lock chamber device as claimed in one of the claims 13 through 15, wherein the buffer unit (EB1) is connected with the second lock chamber (EK2) through lockable conduits (2, 8). 17. Lock chamber device as claimed in claim 1, wherein said second lock chamber (EK2) is provided with a second buffer unit (EB2) which is connected through lockable conduits. 18. Lock chamber device as claimed in claim 17, wherein to the second buffer unit (EB2) is assigned a sixth pump set (P7) discharging the buffer volume of the second buffer unit (EB2). 19. Lock chamber device as claimed in claim 1, wherein said first pump set (PI), through an eight conduit (7), is connected with an eight valve (V8) to the third pump set (P4) with one or various parallel integrated, single-or multistage vacuum pumps (P4a, P4b). 20. Lock chamber device as claimed in claim 1, wherein the first (EKl) and second lock chambers (EK2) are disposed in a reciprocally adjacent position and especially compose first and second lock chambers of a double-stage or triple-stage lock or second and third lock chambers of a triple-stage lock device. 21. Lock chamber device as claimed in claim 1, wherein the lock chambers are provided in the inlet and/or outlet area. 22. Process for evacuation of lock chamber by a multistage lock chamber device as claimed in claim 1, comprising the steps of double-stage or multistage pressure equalization, wherein a first pump set (P1)is being utilized not only for discharging a first lock chamber (EKl) and evacuation of second lock chamber (EK2) within one cycle, initially only the first lock chamber, subsequently the first and second lock chambers. 23. Process for evacuation as claimed in claim 22, wherein second lock chamber is evacuated by a second pump set (P2, P3) additionally and/or alternately, and a third pump set (P4a, P4b) of the first and second pump set is sequentially integrated, which alternately carries out pre-pumping action of the first or second pump set, or both. 24. Process for evacuation as claimed in claim 22, wherein a first lock chamber (EKl) is being subject to a sudden pressure reduction, caused by pressure equalization with an evacuated buffer unit. 25. Process as claimed in claim 24, wherein a second lock chamber (EK2) serving as internal buffer unit, so that through a sudden pressure equalization between the evacuated second lock chamber (EK2) and the first lock chamber (EKl), the pressure level in the first lock chamber (EKl) is being suddenly reduced.

Full Text

The present invention relates to a lock chamber device for a vacuum treatment plant.
The present invention refers to a lock chamber device according to the preamble of claim 1 and 14, respectively and to a process for operating a multistage lock chamber de¬vice.
Glass panels are being coated, for example, in vacuum coating plants, under high-vacuum conditions, at pressures within the range of 5 x 10-4 hPa until 1x10-2 hPa, espe¬cially within the range of 3 x 10-3 hPa for sputtering processes. In order to increase plant productivity figures and to avoid the requirement of having to evacuate the entire installa¬tion for each substrate and, especially, the high-vacuum section, load and unload locks are being used for the substrates.
In order to improve the material flux rate and increase productivity figures, in modern in-line coating plants, separate load and unload lock chambers are being used. A simple so-called 3-chamber coating unit consists of a load lock, in which the substrate is being pumped from atmospheric pressure to an adequate transition pressure of f.ex. p = 5E-2 hPa, of a sequential vacuum coating section (process chamber) and an unload lock, in which, by means of ventilation, said substrate is again being adjusted to the atmospheric pressure level.
The task of lock chambers in evacuating as quickly as possible to a sufficient and lowest possible transition pressure to the process range. While ventilation may take place in

a few seconds, without utilizing pumps, for evacuating purposes, a certain vacuum pump stand must be connected to the lock chamber.
A co-decisive factor for productivity and concurrent economical utilization of an inline coating unit, is the so-called cycle- i.e. station time, i.e. the time which has to be used per batch of substrate before the next batch of substrate may be introduced into the unit, or the average processing time per substrate batch under continuous operating conditions. In order to achieve, for example, a cycle time of 2 min, the lock chamber must be in condition to deliver within t According to the known relation:
(Formula Removed)
with t =•= pump time v « volume s =» pumping capacity P0 - start pressure (atmospheric pressure) Pi => target pressure (transfer pressure, lock reversing pressure),
it becomes evident that there arc clearly two possibilities to reduce the pump time and consequently also the cycle time.
> Volume reduction of lock chamber
> Increase of pumping capacity coupled to the lock chamber.
Since both possibilities have technical and economical limits, in these in-line coating plants with high productivity rates and corresponding reduced cycle time, measures have been taken to subdivide the evacuation-/ventilation process into two or more lock chambers For the inlet side, this implies, for example, that within a primary load lock, evacuation takes place from atmospheric pressure until an intermediate pressure of, for example, 10 hPa, while in a secondary lock chamber, this action takes place from the intermediate pressure (i.e. equalization pressure) until the transfer pressure, for example 5E-2 hPa. In such a 5-chamber unit (2 load locks, 2 unload locks, 1 process chamber), load and unload action is being split up between two chambers and, thus, takes place in two steps, being distributed in two cycles. Thus, for example, in architectural glass panel coating units, with a lock chamber volume of approximately 2 m3 until 5 m3, it was possible to reduce the cycle time from approximately 60 s until 90 s, until approximately 40 s until 50 s. In order to attain still shorter cycle times, for example t erational range, i.e. for example, assigning to the first load lock chamber (1) an atmosphere-fnendly pump stand for the pressure range of 1000 hPa until, for example, 10 hPa, while for the second load lock chamber (2), a multistage, for example a 3-stage, Roots pump stand for the pressure range of 10 hPa until 2E-2 hPa was assigned.
Document US 4,504,194 discloses an apparatus for high speed vacuum pumping of an air lock. For this purpose an expansion tank with a volume larger than the volume of the air lock is provided. The expansion tank is evacuated by a vacuum pump connected to the expansion tank. However, the apparatus is only suitable for lock chambers having a small volume, and for processes where the processing period is long compared with the evacuation period Using the apparatus in units with large volume lock chambers, e.g. m architectural glass panel coating units, is not feasible-It is, thus, a task of the present invention to improve the operational efficiency of a lock chamber unit for vacuum coating plants, especially of the existing 5-charnber, or 7-chamber systems respectively, being thus improved with two up to three load and unload lock chambers, as well as with a process chamber, and especially achieving shorter evacuation times and thus shorter cycle times for the lock chamber unit In view of the improved operational efficiency, also the costs for the pump sets of the lock chambers should be reduced, i.e. lock chambers should be saved, which, again, should offer a cost and space advantage. Another aspect of the present invention consists in attaining lower transition pressures at given cycle and pump times.
This task is solved by a lock chamber unit with the features of claims 1 or 14, as well as with a process for operating a lock chamber unit with the features of claim 25 or 28 Advantageous embodiments are an object of the dependent claims.
Based on a first aspect, the present invention is based on the recognition that the operational capacity of the pump sets and, thus, the time for evacuation of lock chambers may be improved i.e. reduced when, according to the corresponding requirements, said pump sets are variably adapted to the individual load lock chambers, since a highest possible use of the pump sets is being envisaged. It is thus possible, by utilizing existing pressure pumps, to achieve an increase of the effective pumping capacity i.e. a shorter transfer of the substrate from one load lock chamber to another chamber. According to the invention, it is no longer rigidly considered that a pump unit is available for a certain load lock chamber, but the basic idea of the invention consists in that different pump sets may be adequately grouped, united or regrouped reciprocally during the inlet process, in order to attain an ideal pump capacity, i.e. to render feasible an earliest possible transfer from one lock chamber to another chamber, at transfer pressures still at a high level.
Accordingly, a first pump unit, primarily designed for a primary lock chamber, will not only be used for this chamber, but also for a second lock chamber, and only corresponding connections will have to be provided from the pump unit to the first lock chamber and to the second lock chamber According to the requirements and stage of the loading process, it is, thus, possible to offer the pumping capacity, i.e. absorbing capacity, of the first pump unit either to the first load lock chamber or to the second load lock chamber or to both chambers simultaneously-
Additionally, this first pump set is not only assigned directly or indirectly to the second load lock chamber, but the first pump set, according to a preferred alternate embodiment, will be sequentially added to said load lock chamber on an additional i.e. alternate basis, as a pre-pumpmg stage for a second pump set, primarily designed for evacuation of the sprnnd lock chamber
It is thus possible to further expand the possibilities of utilization of the first pump set, providing a more efficient pumping capacity distribution.
According to another preferred embodiment of the present invention, a third pump set is being foreseen, which, as a sequentially added pumping stage for the second pump set, especially in the area of the lock chamber with lower pressures, reinforces the second pump set, especially when the first pump set is no longer available as a pre-pumpmg stage, since it should be primarily used for the first lock chamber
Alternately to the above, according to another embodiment, a third pump set may be assigned as a common pre-pumping stage for the first pump set and the second pump set, and the third pump set may be utilized either as a pre-pumpmg stage for the first pump set or for the second pump set or jointly for both. It is also thus insured that the third pump -similar to the first pump set - may offer to the load lock chambers an altered pumping capacity, especially during the loading process. Accordingly, or the pumping capacity obtained will thus be utilized to reduce the evacuation time or lower transfer pressure rates will become feasible
According to another advantageous embodiment of the present invention, in the case of pumps of a pump set adjacently connected in a parallel direction, a corresponding by-pass may be foreseen, so that by activating/liberating said by-pass and adequate separation of the remaining connecting conduits, this pump is being sequentially connected to the prior parallel connected pumps, in order to produce a multistage pumping stand. This offers the advantage that according to the required pumping capacity, i.e. pressure conditions, by simple regrouping of the pumps, the pumping capacity may be adjusted according to requirements. For example, in the event that the first pump set is available as a pre-pumping stage for the second pump set, the corresponding pump may be operated parallel with the other pumps in
the second pump set, while upon deactivation of the first pump set, as pre-pumping stage, the pump with the by pass will be sequentially connected to the other pumps of the second pump set, in order to compound a multistage pumping stand with these sets.
According to another advantageous embodiment, in the case of pumps connected m an adjacent parallel position, especially pumps of the second pump set for the second lock chamber, in a position parallel to said pumps, a differential pressure bypass lid may be integrated, so that the parallel pump sets, especially the second pump set, may be automatically operated according to the prevailing pressure conditions also in the case of high intake pressures. Due to the action of the differential bypass lid K2, the outlet section of the parallel integrated pumps is being connected, i.e. short-circuited, with the aspiration section, for example over the second lock chamber, in order to provide a maximum differential pressure. The maximum compression rate of the parallel integrated pumps and, consequently, also their capability of mechanical, i.e. electrical, acceptance, are being limited, so that these pumps may be used already at considerably higher intake pressures than without a differential pressure bypass lid As a consequence, such parallel integrated pumps, such as, for example, Roots pumps, may accompany the pumping action also at relatively high pressure rates, offering their pumping capacity in a prior pumping evacuation phase. It is, thus, possible to waive complex pumps for the second pump set, such as, for example, Roots pumps, cooled before the inlet phase, which may control a high admissible differential pressure of, for example, > 800 hPa. Additionally, it is, thus, also possible to let the second pump set permanently connected with the second lock chamber, without the need of closing corresponding valves in the conduits leading to the lock chamber. This also provides a better utilization rate of the pumps of the second pump set, i.e. an altogether more simple design of the pump set. Instead of only one parallel integrated differential bypass lid, each pump may
have its own differential pressure bypass hd, or, else, it is possible to use pumps with integrated (differential pressure) bypass lids.
Evidently, the different pump sets may encompass one or various parallel reciprocally integrated, single or multistage, vacuum pumps, such as, for example, oil-sealed or dry-compressing vacuum pumps, especially rotary vane pumps, rotary piston pumps, rotary plunger pumps, roots vacuum booster, dry running pumps especially axial pumps, Roots pumps, especially pre-admittance-cooled Roots pumps, etc.
Due to the variable embodiment of the pumping capacity, it is especially also possible to completely waive oil-sealed pump sets, utilizing only dry-compressing vacuum pumps, such as, for example, axial pumps.
According to a second aspect, an acceleration of the transfer process is attained by providing buffer devices, which offer a buffer volume, which, for example, is being evacuated during occasions when the pumping capacity of certain pump sets is not required for the immediate evacuation process, or when direct outlet action is not yet feasible The absorption capacity, i.e. the pumping capacity, is thus being stored in the buffer set and, at the right moment, it is being offered to the lock chambers by a sudden pressure equalization, for the purpose of evacuation, i.e. pressure reduction of lock chambers. The sudden pressure equalization enables a considerably fast evacuation within fractions of seconds, i.e. practically on a "zero time" basis.
Preferentially, for each lock chamber a specific buffer device may be provided with a corresponding buffer volume, and additionally to these external buffer devices, the lock chambers specifically also may act as buffers, when the lock chamber, closest to the vacuum area, is previously being evacuated and subsequently, with a preceding lock chamber, providing a pressure equalization for a sudden pressure reduction.
The external buffer devices may be equipped with separate pump sets, however it is especially convenient to utilize existing pump sets, already provided for the lock chambers, separately or additionally to separate pump sets of said buffer devices An optimal utilization of said lock chamber pump sets may thus be assured.
It is evident for the specialist that the measures described may be materialized both on the load, as well as on the unload side of the lock.
Other advantages, features and characteristics of the present invention will become clear based on the subsequent, detailed description of preferred embodiments, based on the attached drawings The drawings indicate in a merely schematic form:
Fig. 1 - a schematic representation of the inlet section of a glass coating unit, with corresponding pump set;
Fig. 2 - another embodiment of a lock chamber with an inlet section, comparable to representation of Fig 1,
Fig. 3 - a third embodiment of an inlet section with a representation similar to Fig. 1; and
Fig. 4 - another embodiment of a lock chamber.
Fig 1 features a schematic representation of the mlet section of a vacuum treatment plant, in. the present case a glass coating plant, with two inlet chambers EK1 and EK2, as well as a transfer chamber TK and a sputtering chamber SKI. The sputtering chamber SKI and the transfer chamber TK feature plurality of high-vacuum pumps, in order to adjust high-vacuum conditions for the coating area.
The inlet chambers EK1 and EK2 are separated against the outer environment by means of valve flap VK1, and against said transfer chamber TK by means of valve flap VK3 Amongst said devices, separation is being produced by valve flap VK2.
A valve VF)ut for ventilating said inlet chamber EK1 is being provided at said inlet chamber EK1.
Additionally, at inlet chamber EK1, a first pump set PI is provided with five parallel integrated rotary vane pumps, connected with inlet chamber EK1 over conduit 1 and valve VI. Furthermore, pump set PI is connected with inlet chamber EK2 through conduit 2 and valve V2. Also, through conduit 3, which may be closed through valve V5, pump set PI is connected with the second pump set P2, P3, formed by parallel integrated Roots pumps P2 andP3.
Roots pumps P2 and P3 of the second pumps set are interconnected through conduit 5 at the outlet side, and conduit 5 may be locked over valve V7. Pumps P2 and P3 are also connected with said inlet chamber EK2 through conduits 4 and valves V3 and V4 therein integrated. Additionally, the third pump set P4 is being provided based on a double-stage Roots pump stand with a Roots pump and subsequently integrated rotary vane pump, connected through conduit 6, featuring valve V6, with the second pump set and here especially with conduit 5.
Furthermore, at inlet chamber EK2, high-vacuum pumps are provided, reciprocally connected in parallel projection and which over valves Vhl through Vh3, may be coupled with inlet chamber 2.
The inlet process in such a lock chamber unit takes place in such a fashion that initially valve lid VK.1 of the first inlet chamber EK1 is being opened and substrate is being transported into the said inlet chamber EK1. Subsequently, valve lid VK1 will be closed and valve VI will be opened towards pump stage PI, so that inlet chamber EK1 may be evacuated.
Subsequently, valves V3, V4 and V5 are being closed and valve V2, as well as valve lid VK2, are being opened. This takes place, for example, with a pressure of 200 hPa. Simultaneously, the substrate is now being moved from the first inlet chamber EK1 towards the second inlet chamber EKZ
Once an adequate pressure level has been attained, for example of 80 hPa, valves V5 and V3 will be opened and valves VI and V2 will be closed. Simultaneously, or with reduced delay, valves V4 and V7 will be opened Also, valve V6 will now be opened, this valve V6, however, being provided on an optional basis, having to be present only with a certain type of the pump stand P4. If, for example, the third pump set P4 is being composed by a forepump and a Roots pump with a bypass conduit, said optional valve V6 may be waived, since, in this case, the third pump set P4 may be activated and continuously operated at atmospheric or very high intake pressures, for example of 100 hPa up to 300 hPa
Subsequently, valves VI and valve lid VK2 are being closed, so that inlet chamber EK1 may again be ventilated and valve lid VK1 may be opened, in order to accept the next substrate in inlet chamber EKL
Also, valve V5 is now being closed, so that the first pump set PI no longer operates as a forepump stand for the second pump set P2, P3, i.e. parallel in relation to the third pump set P4, but not only the third pump set P4, as a retaining pump stand, is subsequently connected to the second pump set P2, P3, while due to opening of valve VI, the first pump set will again be utilized for evacuating the first inlet chamber EK1.
In the second inlet chamber EK2, the optional high-vacuum valves Vhl until Vh3 may now be opened, m order to regulate said inlet chamber EK2 at high-vacuum conditions With an approximate pressure stand of 0,3 hPa, valves V3 and V4 may be closed and after the corresponding vacuum conditions have been attained, for example with a pressure of 2 x
10 ~3 hPa, valve lid VK3 may be opened, in order to transfer the substrate into the processing area (transfer chamber)
It is important during this phase that the above described procedures take place inside, i.e. with the two inlet chambers partly in a simultaneous fashion, so that a lowest possible cycle time is being reached. Due to the fact the first pump set PI is connected not only with inlet chamber EK1, but also with the second inlet chamber EK2, the first pump set PI may be utilized for a longer period of time, in order to contribute towards a shorter inlet, i.e. admission, time
It is an advantage of the unit described, i.e. of said procedure, that valve lid VK2 between inlet chamber EK1 and inlet chamber EK2 cannot be opened only at acceptance pressure of the Roots pumps P2 and P3 of the second pump set, i.e. at approximately 15 hPa, but this may take place already at higher pressures, in the range of 100 hPa through 200 hPa, especially 150 hPa Pumping times will, thus, be cut down inside inlet chamber EK1 by approximately one third, or pump set PI could be reduced by a third, relative to the pumping capacity
Additionally, it is advantageous that the first pump set PI may be used with pumps P2 and P3, through valve V5, as a forepump stand of the second pump set, so that the second pump set with pumps P2 and P3 may be used at much higher pressures. A utilization rate of approximately 100 hPa, instead 10 hPa, will now become feasible.
Especially, opening and closing times of the different valves, especially opening of V5, V7, V3 and V4, as well as closing of V2, may be reciprocally synchronized in such a fashion, that no interruption of the pumping capacity is caused and commuting times of cycle times are, thus, not being negatively influenced.
The third pump set P4 is designed to form with the second pump set P2, P3, a multistage pump stand, until the necessary transfer pressure, i.e. activation pressure, for the optional high-vacuum pumps PHI until PIHD has been attained- Also, the third pump set P4 is designed to reinforce the second pump set P2, P3, when the first pump set PI is being required for evacuating said inlet chamber EK1, thus no longer being available as a forepump stand for the second pump set P2, P3.
In the alternative embodiment of Fig. 3, which largely corresponds to the embodiment of Fig. 1, and, consequently, will henceforth only be described regarding the differences, with the second pump set, additionally to the Roots pumps P2 and P3, a third Roots pump P5 is parallel integrated, connected with inlet chamber EK2 over an additional conduit 14 and valve 10 therein disposed Additionally, in a parallel sense in relation to the third pump P5, a conduit 8 is foreseen, disposed between the inlet chamber conduit 14 and conduit 5, connecting the outlet side of pumps P2, P3 and P5, and again a valve Vll is integrated in conduit 8. Conduit 8 discharges between valve V10 and pump P5 into conduit 14. Furthermore, a valve V12 is integrated between the inlet of conduit 8 in conduit 5 and inlet of conduit 6 in conduit 5. This bypass set to pump P5, by closing valve V10, as well as valve V12 and opening of valve Vll, renders it possible to integrate pump P5 sequentially to Roots pumps P2 and P3, so that pump P5, with the third pump set P4 - here formed by a single stage pump set based on a rotary vane pump - forms a multistage Roots pump stand.
Consequently, at the moment in which the first pump set PI no longer is available as sequentially integrated pumping stage for the second pump set - since the first pump set PI again has to evacuate inlet chamber EK1 - it is feasible to attain a potential, multistage pump set for inlet chamber EK2 by regrouping pump P5, i.e sequential integration of pump P5 to pumps P2 and P3. Accordingly, before valve V5 or V7 is being closed, valves V10 and
V12 are being closed and valve Vll will be opened, in order to sequentially integrate pump P5 with pumps P2 and P3 Except for the above, the sequence corresponds to the inlet process in the inlet area of Fig-1. The advantage of this variant, however, is seen in the fact that dunng the discharge, i.e. outlet phase with the second pump set P2, P3, P5, by closing valves V10 and V12 and opening valve Vll, a three-stage Root pump stand may be formed with the second and third pump set P4 as a forepump unit. The third stage with Roots pumps P2 and P3 may be doubled or halved by opening/closing V7, or may be split up between the first pump set PI and the third pump set P4, respectively.
In the embodiment of Fig. 2, the first pump set is formed by two parallel integrated, singled stage and pre-admittance cooled Roots pumps, connected over conduit 1 and valve VI with inlet chamber EK1 and over conduit 2 and valve V2, are connected with mlet chamber EK2 (The pre-admittancc gas cooling is not shown).
The second pump set consists of the double-stage parallel Roots pumps P2 and P3, which again are connected with mlet chamber EK2 over conduits 4 and corresponding valves V3 and V4.
At the discharge side of the first pump set PI and of the second pump set P2, P3, a third pump set P4a, P4b of parallel integrated, single stage dry-running pumps for example m the form of axial pumps, is foreseen, which over conduit 6 is connected with the second pump set P2, P3, i.e. with their joint conduit 5, i.e. over conduit 7, with the first pump set PI. In conduit 6, there is valve V6 and in conduit 7, valve V8 is foreseen, so that the corresponding connections may be separated Additionally, in the connecting conduit between the parallel integrated axial pumps P4a and P4b, a valve V9 is foreseen. With the embodiment of Fig. 2, both inlet chamber EK1, as well as inlet chamber EK2, may be discharged over multistage pumping stands, and especially due to this disposition, oil-scaled forepumps
may be waived, and alternately, in an especially advantageous form, exclusively dry-compressing pumps may be used-Admission of a substrate into the vacuum treatment plant of Fig. 2, takes place in such a fashion that initially valve lid VK1 of the first inlet chamber EK1 is being opened, and substrate is being transported into inlet chamber EK1. Subsequently, valve hd VK1 is closed and valve VI to the first pump set PI is opened, and the gas transported at high pressure levels, for example 500 until 1000 hPa, contingent upon the forepump level of the third pump set P4, is being evacuated mto the atmosphere over discharge lid Kl. As of an acceptance pressure Pu of, for example, 300 hPa, valve V8, i.e. V8 and V9, are being opened, so that a multistage pump set is being provided for discharging said inlet chamber EK1
Valves V3 and V4 are now being closed, while valve V2 and valve lid VK2 between inlet chamber EK1 and inlet chamber EK2 are being opened. The substrate is now being transported from the first inlet chamber EK1 into the second mlet chamber EK2.
Subsequently, valves V6, V3 and V4 are being opened and eventually valves V8 and V9 are being closed. Then, valve lid VK2 and valve VI are being again closed, to that the admittance chamber, i.e inlet chamber EK1, is being ventilated and valve lid VKl may be opened, in order that the next substrate may be introduced into mlet chamber EK1
Subsequently, valves V8 and V2 are being closed and VI is opened to evacuate the first inlet chamber EK1. The high-vacuum pumps PHI until PHS - according to the operation of the first example according to Fig 1 - may be connected with inlet chamber EK2 over valves Vhl until Vh3, so that valves V3 and V4 may subsequently be closed When inlet chamber EK2 corresponds to vacuum conditions of sputtering chamber 1, valve lid VK3 will be opened and substrate will be introduced into the processing area. Also here, evidently, the processes m both load lock chambers EK1 and EK2 partly take place simultaneously.
The advantage of this disposition consists in that the first pump set PI, and also the third pump set P4, may be utilised nearly on a 100% basis, i.e practically over the entire mlet, i.e. admission cycle. Additionally, also here chamber valve VKL2 may be opened already at higher pressure levels, for example 100 until 400 hPa, especially 250 hPa, which, compared to an opening at approximately 15 hPa, corresponding to the acceptance pressure of Roots pumps P2 and P3, corresponds to an evidently shorter pumping time for discharging mlet chamber EK1, i.e. renders feasible a more compact construction of the corresponding pump stand
Due to the variable conditions of utilization of a third pump set P4 as a forepump stand, both of the first pump set PI as well as of the second pump stand P2, P3, also for inlet chamber EK1 and inlet chamber EK2, a multistage pump stand is being provided, for van-able utilization. Especially, with all embodiments shown, the pumping capacity, i.e. the absorption capacity, may thus accompany the substrate at the inlet side or generally along the direction of evacuation from atmosphere to vacuum, i.e. according to the local requirements of pumping capacity, so that this results in a considerable capacity increase and time reduction.
Fig 4 shows another embodiment of a lock chamber unit according to the invention, which is largely coincident with Fig 3
A first difference is to be found in the fact that the second pump set, with the parallel integrated pumps P2, P3 and P5, features no bypass 8 parallel to pump P5, such as m Fig.3, but, parallel to conduits 4, with which pumps P2, P3 and P5 are connected to the second mlet chamber EK2, a differential pressure bypass lid K2 is provided, connected with the second inlet chamber EK2 over conduit 9 and valve V17. By means of this disposition, it is possible to couple the parallel integrated Roots pumps P2, P3 and P5 with relatively high
intake pressure, m order to be able to utilize - according to the adjusted differential pressure - already with high intake pressures, a portion of their absorption capacity for rapid evacuation Due to a connection of the outlet side of pumps P2, P3 and P5 with the absorption side, over the second inlet chamber EK2, bypass lid K2 foresees that pumps P2, P3 and P5 only have to overcome a differential pressure which may be adjusted at bypass lid K2. For this purpose, for example, said bypass lid may consist of a spring-loaded or weight-loaded valve, which opens towards the direction of the chamber at the occasion of a determined overpressure at the evacuation side of Roots pumps P2, P3 and P5. Valves V3, V4 and V10 may thus be opened, or remain open, at higher absorption pressures and/or the utilization of pre-adrmttance cooled roots pumps, which also could be used at higher pressures, may be waived, so that it is possible to reduce the costs for the second pump set, providing, simultaneously, a higher pumping capacity. Evidently, instead of a differential pressure bypass K2, vanous differential pressure lids could be provided, for example for each pump P2, P3 or P5, or it would be possible to utilize Roots pumps with integrated bypass lids.
The disposition of said bypass lid K2 offers the additional advantage that valves VI7, V3, V4 and VI0 during their operation may remain permanently open, i.e. they do not have to be forcibly closed in each cycle, especially when the high-vacuum pumps PHI through PHJ are waived. The operation is thus also accordingly simplified.
A second difference of the embodiment of Fig. 4, as compared with embodiment of Fig. 3, consists in that the parallel integrated vacuum pumps of the first pump set PI may be coupled over a conduit 10 and valves V13 and V15 therein foreseen, as a sequential stage to the third pump set P4 or parallel to other pumps P97 over valve V16, and P10, over V13. By closing valve V5 and opening valves V6, V13, V15 and eventually V9, it is thus possible to form, dunng the evacuation stage, a multistage pumping level with the first pump set PI, the
fourth pump set P4 and the second pump set P2, P3 and P5. Thus, starting at the two-stage pumping level, without interrupting the pumping capacity, an almost perfect transition to a three-stage pump level may take place, or, in general terms, of a n-stage pumpmg level, a n+1 -stage pumping level may be formed. It is evident that, consequently, pump P9 with valve V16 only could be provided on an optional basis.
Another essential difference of embodiment of Fig. 4, as compared to the preceding embodiments, consists in that additionally it features an outer buffer unit EB1, which through valvt V14 and conduit 8, as well as conduit 1, is connected with the first inlet chamber EK1. Buffer unit EB1 offers a buffering volume, which may be absorbed through the optionally foreseen fifth pump set P6 or through the first pump set PI. With the thus evacuated buffer volume, after opening valves VI and V14, pressure inside the first inlet chamber EK1 may be suddenly reduced In this form, it is possible to utilize pumping capacity, i.e. absorption capacity, in periods of time, in which pumping capacity i.e. absorption capacity for direct evacuation of inlet chambers EK1 and EK2 is not being required or when the additional integration of the fifth pump set P6 and inlet chamber EK1 should not be advantageous, due to pressure conditions. This pumping capacity, i.e. absorption capacity, as it were, is being stored in buffer unit EB1 and afterwards, in case of need, is being offered to the first inlet chamber EK1.
In a similar fashion, also the second inlet chamber EK2 may act as an internal buffer unit, when by opening valves VI and V2, a pressure equalization is being made between inlet chambers EK1 and EK2, so that also here the pressure declines suddenly. Especially in the case of a reciprocally adjusted combination of a pressure equalization between the first inlet chamber EK1 and buffer unit EB1 and subsequent pressure equalization between the first inlet chamber EK1 and the second inlet chamber EK2, it is possible to attain two stages
of a quick pressure reduction, and also here the absorption capacity relative to the second inlet chamber EK2 may be utilized during a large penod of time of the transfer process
Additionally, a second outer buffer unit EB2 may optionally be provided with corresponding optionally foreseen additional sixth pump set P7, by means of which a pressure equalization between the second inlet chamber 2 and the second buffer unit EB2 also provides a sudden pressure reduction. Instead of the sixth pump set P7, the buffer volume of the second buffer unit EB2 may also be evacuated through the second (P2, P3, P5), third (P4) and/or other pump sets already provided for the second inlet chamber EK2, such as, for example, P9
In the embodiment of Fig. 4, it is also indicated that high-vacuum pumps PHI through PH3 may be abandoned in all embodiments, and are therefore only optional when over the absorption capacity for the second inlet chamber EK2 a sufficient vacuum may be obtained
Valves V3, V4, VI0 and V17 arc designed to be capable of separating the second inlet chamber EK2 from the pump stand and render possible an independent ventilation of the chamber, or of the pump stand, respectively. If it should be considered that this is not required, these valves may also be waived. Valves V3, V4, V10 and V17 are, however, needed in any case, when the second buffer unit EB2 is to be evacuated over the second pump set P2, P3, P5, since then a separation from the second inlet chamber EK2 will be required. However, if the second buffer unit EB2 is to be evacuated only through the sixth pump set P7, the second buffer unit EB2 could also be directly united with the second inlet chamber EK2bymeansofV18.
In an embodiment according to Fig. 4, the transfer process takes place in the following way Initially, valve lid VK1 of the first inlet chamber EK1 is being opened and the substrate is being transported into the first inlet chamber EKl Subsequently, valve hd VK1 is closed
and valve VI is opened towards pump stand PI. Valve V14 is open during this process and valves V2, V5 and VI3 or V15 are closed. Due to the pressure equalization with the evacuated buffer volume of the first buffer unit EB1, pressure in the first inlet chamber EK1 is suddenly reduced from atmospheric pressure to approximately 400 hPa. VI4 is now being closed and V2 js being opened, so that a second sequential pressure equalization takes place, precisely between the first inlet chamber EK1 and the second evacuated inlet chamber EK2. With approximately identical chamber volumes of the first and second inlet chambers EK1 and EK2, pressure in both chambers is suddenly regulated to approximately 200 hPa. Valve lid VK2 is now being opened and substrate is moved from the first inlet chamber EK1 into the second inlet chamber EK2. During this process, valve V5 is being opened and valves VI and V2 are being closed.
Simultaneously, or with reduced delay, valves V6 and V15 and, eventually, V13 are being opened and valve V5 is being closed, so that there is no longer a bypass towards the third pump set P4, now prevailing a multistage pumping level with pumping stages from the first pump set PI, second pump set P2, P3, P5 and third pump set P4
Valve lid VK2 is now being closed and the first inlet chamber EK1 is ventilated over valve VFlut Subsequently, valve lid VK1 may be opened and the next substrate may be transported into the first inlet chamber EK1. The optionally provided high-vacuum pumps PHI through PHJ may now be connected with the second inlet chamber EK2, by means of opening valves VH1 through VH3. fa this case, valves V3, V4, V10 and V17 are closed. If no high-vacuum pumps are foreseen on the second inlet chamber EK2, these valves may if necessary remain continuously open during operations. Valve lid VK3 may now be opened and substrate may be transferred towards the process area, i.e. into transfer chamber TK. Valves V13 and VI5 are being closed and valve V14 will be opened, so that the first pump set
may evacuate the buffer volume of the first buffer unit EB1 If the fifth pump set P6 is foreseen, the buffer volume of the first buffer unit EB1 may be evacuated jointly through the first pump set PI and the fifth pump set P6. The inlet process will then be reinitiated.
If with the lock chamber arrangement of Fig. 4, the second outer buffer unit EB2 is provided, then valve V18 will be opened for pressure equalization between the second inlet chamber EK2 and the previously evacuated buffer volume of the second buffer unit EB2, after substrate has reached the second inlet chamber EK2 and after valve lid VK.2 has been closed. Pressure in the second inlet chamber EK2 may thus be suddenly reduced from approximately 30 hPA to 10 hPa.
During transportation of substrate from the second inlet chamber EK2 into transfer chamber TK, valves V3, V4, V10 and V17 are being closed, in order to utilize the second pump set with pumps P2, P3 and P5 for evacuating buffer volume of the second buffer unit EB2.
With the solution now proposed, according to embodiment of Fig 4, based on the buffer solutions, it is possible to produce the pressure reduction through a double-stage pressure equalization in the first lock chamber within quite short time periods, i.e. periods much smaller than a second, so as to be able to transfer immediately the substrate into the second lock chamber With a second buffer unit, this effect may also be utilized for the second lock chamber EK2.
The process now presented in the inlet area, in a correspondingly analog fashion may also be utilized for the outlet, i.e. unload area, without the requirement of a closer description ainrp the anpriali may Hcrtakft the eorresnondme adaotation in a simple fashion.

WE CLAIM:
1. Lock chamber device for a vacuum treatment plant with at least two lock
chambers (EK1, EK2) which are sequentially arranged within the vacuum
treatment plant for carrying out a double-stage or a multi-stage pressure
equalization process, and whereas both lock chambers (EK1, EK2) are
separated from each other by a valve flap (VK2) and whereas a first pump set
(PI) for evacuating a first lock chamber, as well as a second pump set (P2, P3)
for evacuating a second lock chamber, are provided characterized in that;
said first pump set (PI) is connected with both the first (EK1) as well as with the second (EK2) sequentially arranged lock chamber by means of lockable conduits (1, 2), so that the first pump set may evacuate either the first or the second or both lock chambers.
2. Lock chamber device as claimed in claim 1, wherein to the first (PI) and the second (P2) pump set is connected a third pump set (P4 a, b) through correspondingly lockable conduits (6, 7), so that the third pump set may be sequentially integrated either into the first or the second or into both pump sets.
3. Lock chamber device as claimed in claim 1, wherein said first pump set (PI) is connected with the second pump set (P2, P3) by means of lockable conduits (3), so that the first pump set may be sequentially integrated with the second pump set.
4. Lock chamber device as claimed in one of the preceding claims, wherein the pump sets (PI, P2, P3, P4) encompass various parallel and/or sequentially integrated pumps.
5. Lock chamber device as claimed in claim 4, wherein said pump sets encompass oil-sealed and/or dry-compressing vacuum pumps, especially rotary vane pumps, rotary piston pumps, rotary plunger pumps, vacuum roots booster, dry- running pumps, especially axial pumps, Roots pumps, especially pre-admittance cooled Roots pumps.

6. Lock chamber device as claimed in claim 5, wherein said pumps parallel integrated in one pump set, feature a lockable bypass (8), through which at least one of the pumps may be connected sequentially relative to the other pump, in order to compose a multistage pumping stand.
7. Lock chamber device as claimed in claim 1, wherein said lock chamber (EK1, EK2) adjacent to the process chamber, one or various high-vacuum pumps (PHI, PH2, PH3) are provided by means of lockable conduits.
8. Lock chamber device as claimed in claims 1 to 7, wherein parallel to one, especially to the second pump set, a bypass lid (K), commanded by differential pressure, is integrated, which, in the event of high pressure applied on the evacuation side, especially in the second lock chamber (EK2), represents a bypass from the outlet side towards the inlet side of pump sets (P2, P3, P5), so that a maximum differential, critical pressure level, preferably adjustable, being applied to the parallel integrated pump set is not being exceeded and the pumping capacity of the pump set is continuously being utilized on a pressure dependent basis.
9. Lock chamber device as claimed in one of the claims 1 or 3 or 5, wherein the first pump set (PI), with one or different parallel integrated, single-or multistage, especially atmosphere-friendly vacuum pumps, through a first conduit (1), featuring a first valve (1), is connected with the first lock chamber (EKI), and though a second conduit, featuring a second valve, is connected with the second lock chamber (EK2) and through a third conduit (3), featuring a third valve (V5), is connected with the second pump set (P2, P3), with the second pump set featuring one or various parallel integrated, single-or multistage vacuum pumps, which, over a fourth or other conduits (4), featuring a fourth valve (V3, V4), are connected with the second lock chamber (EK2) and the parallel integrated pumps of the second pump set are reciprocally interconnected through fifth conduits (5) with a fifth valve (V7).

10. Lock chamber device as claimed in claim 9, wherein at the outlet side of the second pump set (P2, P3), especially at the fifth conduit (5), uniting pumps (P2, P3) of the second pump set, the third pump set (P4) is coupled with one or various parallel integrated, single-or multistage vacuum pumps through a sixth conduit (6) connected to a preferentially provided sixth valve (V6).
11. Lock chamber device as claimed in claim 9 or 10, wherein said first pump set encompasses rotary vane pumps, said second pump set encompasses Roots pumps and the third pump set encompasses double-stage Root pump stands or a single-stage pump stand with rotary vane pumps.
12. Lock chamber device as claimed in one of the claims 9 through 11, wherein between the fourth (14) and the fifth (5) conduit, a seventh conduit (8) is provided with a seventh valve (Vll), so that a parallel integrated pump (P5) of the second pump set may be integrated sequentially relative to the other pumps.
13. Lock chamber device as claimed in claim 1, wherein the first lock chamber (EK1) is provided with a buffer unit (EB1) which may be connected through lockable conduits (1, 8).
14. Lock chamber device as claimed in claim 13, wherein the buffer unit (EB1) features a fifth pump set (P6), which evacuates the buffer volume.
15. Lock chamber device as claimed in claim 1, wherein the first pump set (PI) is connected with the buffer unit (EB1).
16. Lock chamber device as claimed in one of the claims 13 through 15, wherein the buffer unit (EB1) is connected with the second lock chamber (EK2) through lockable conduits (2, 8).
17. Lock chamber device as claimed in claim 1, wherein said second lock chamber (EK2) is provided with a second buffer unit (EB2) which is connected through lockable conduits.
18. Lock chamber device as claimed in claim 17, wherein to the second buffer unit (EB2) is assigned a sixth pump set (P7) discharging the buffer volume of the second buffer unit (EB2).
19. Lock chamber device as claimed in claim 1, wherein said first pump set (PI), through an eight conduit (7), is connected with an eight valve (V8) to the third pump set (P4) with one or various parallel integrated, single-or multistage vacuum pumps (P4a, P4b).
20. Lock chamber device as claimed in claim 1, wherein the first (EKl) and second lock chambers (EK2) are disposed in a reciprocally adjacent position and especially compose first and second lock chambers of a double-stage or triple-stage lock or second and third lock chambers of a triple-stage lock device.
21. Lock chamber device as claimed in claim 1, wherein the lock chambers are provided in the inlet and/or outlet area.
22. Process for evacuation of lock chamber by a multistage lock chamber device as claimed in claim 1, comprising the steps of double-stage or multistage pressure equalization, wherein a first pump set (P1)is being utilized not only for discharging a first lock chamber (EKl) and evacuation of second lock chamber (EK2) within one cycle, initially only the first lock chamber, subsequently the first and second lock chambers.
23. Process for evacuation as claimed in claim 22, wherein second lock
chamber is evacuated by a second pump set (P2, P3) additionally and/or
alternately, and a third pump set (P4a, P4b) of the first and second pump set is
sequentially integrated, which alternately carries out pre-pumping action of the
first or second pump set, or both.
24. Process for evacuation as claimed in claim 22, wherein a first lock
chamber (EKl) is being subject to a sudden pressure reduction, caused by
pressure equalization with an evacuated buffer unit.

25. Process as claimed in claim 24, wherein a second lock chamber (EK2) serving as internal buffer unit, so that through a sudden pressure equalization between the evacuated second lock chamber (EK2) and the first lock chamber (EKl), the pressure level in the first lock chamber (EKl) is being suddenly reduced.

Documents:

576-DEL-2005-Abstract-(31-07-2008).pdf

576-del-2005-abstract.pdf

576-DEL-2005-Claims-(06-02-2009).pdf

576-DEL-2005-Claims-(31-07-2008).pdf

576-del-2005-claims.pdf

576-del-2005-complete specification (granted).pdf

576-DEL-2005-Correspondence Others-(22-02-2012).pdf

576-DEL-2005-Correspondence-Others-(31-07-2008).pdf

576-del-2005-correspondence-others.pdf

576-del-2005-description (complete)-31-07-2008.pdf

576-del-2005-description (complete).pdf

576-DEL-2005-Drawings-(31-07-2008).pdf

576-del-2005-drawings.pdf

576-DEL-2005-Form-1-(31-07-2008).pdf

576-del-2005-form-1.pdf

576-del-2005-form-13.pdf

576-del-2005-form-18.pdf

576-DEL-2005-Form-2-(31-07-2008).pdf

576-del-2005-form-2.pdf

576-del-2005-form-3.pdf

576-DEL-2005-Form-5-(31-07-2008).pdf

576-del-2005-form-5.pdf

576-DEL-2005-GPA-(22-02-2012).pdf

576-DEL-2005-GPA-(31-07-2008).pdf

576-del-2005-gpa.pdf

576-DEL-2005-Petition Others-(22-02-2012).pdf

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Patent Number

233109

Indian Patent Application Number

576/DEL/2005

PG Journal Number

13/2009

Publication Date

27-Mar-2009

Grant Date

26-Mar-2009

Date of Filing

16-Mar-2005

Name of Patentee

APPLIED MATERIALS GmbH & CO. KG.

Applicant Address

SIEMENSSTRASSE 100, 63755 ALZENAU, GERMANY.

Inventors:

#	Inventor's Name	Inventor's Address
1	JURGEN HENRICH	AM GEORGENWALD 5, 63694 LIMESHAIN, GERMANY
2	THOMAS GEBELE	ZIEGELSTRASSE 30, 63579 FREIGERICHT, GERMANY
3	MANFRED WEIMANN	NEUWIESENSTRASSE 41, 63755 ALZENAU, GERMANY

PCT International Classification Number

C23C 14/56

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	04 007 820.6	2004-03-31	EUROPEAN UNION