SAFEGUARDING DEVICE, WAFER TRANSPORT CONTAINER WITH AT LEAST ONE SAFEGUARDING DEVICE, SAFEGUARDING SYSTEM AND METHOD WITH THE SAFEGUARDING DEVICE

Abstract

A safeguarding device, in particular a safeguarding device for a wafer transport container includes at least one positive-fit unit configured at least for a safeguarding of a wafer-transport-container opening element of a wafer transport container, which is held in its closure position by a closing mechanism.

Claims

1. A safeguarding device, in particular a safeguarding device for a wafer transport container, with at least one positive-fit unit configured at least for a safeguarding of a wafer-transport-container opening element of a wafer transport container, which is held in its closure position by a closing mechanism.

2. The safeguarding device according to claim 1, wherein the positive-fit unit comprises at least one positive-fit recess and at least one positive-fit element, wherein the positive-fit recess and the positive-fit element are configured to couple with one another in a contact-free fashion in a proper safeguarding.

3. The safeguarding device according to claim 1, further comprising an at least partial integral implementation with the wafer transport container.

4. The safeguarding device according to claim 1, further comprising at least one reset element, which is configured to re-deflect the positive-fit unit at least partly into a safeguarding position and/or to hold the positive-fit unit in the safeguarding position.

5. The safeguarding device according to claim 1, further comprising at least one chamber, which comprises a pressure connection channel that is configured to allow a variation of an inner pressure in the chamber relative to a reference pressure, wherein a differential pressure is calculated from the inner pressure of the chamber and the reference pressure and is configured to influence a safeguarding status of the positive-fit unit.

6. The safeguarding device according to claim 5, further comprising at least one reset element, which is configured to re-deflect the positive-fit unit at least partly into a safeguarding position and/or to hold the positive-fit unit in the safeguarding position, wherein the at least one reset element is arranged, at least to a large extent, inside the chamber.

7. The safeguarding device according to claim 5, wherein the positive-fit unit comprises at least one movably supported positive-fit element, wherein a position of the positive-fit element relative to at least one chamber wall of the chamber depends on the differential pressure.

8. The safeguarding device according to claim 5, wherein the positive-fit unit is configured to take a non-safeguard position if the differential pressure exceeds a limit differential pressure.

9. The safeguarding device according to claim 1, further comprising at least one further chamber having, in a safeguard state of the safeguarding device and in a non-safeguard state of the safeguarding device, an inner pressure that has the same value as an ambient pressure.

10. The safeguarding device at least according to claim 9, further comprising at least one chamber, which comprises a pressure connection channel that is configured to allow a variation of an inner pressure in the chamber relative to a reference pressure, wherein a differential pressure is calculated from the inner pressure of the chamber and the reference pressure and is configured to influence a safeguarding status of the positive-fit unit, and comprising at least one movably supported setting element, which delimits the chamber and the further chamber at least partly.

11. The safeguarding device according to claim 10, wherein the setting element is configured to vary, depending on a pressure difference of the inner pressures of the chamber and the further chamber, an inner volume of the chamber and/or an inner volume of the further chamber.

12. The safeguarding device according to claim 5, further comprising at least one additional further chamber, which is configured to have, in at least one operating state, an inner pressure that differs from the ambient pressure.

13. The safeguarding device according to claim 1, further comprising a linear bearing that is configured to permit a translational movement of the positive-fit unit.

14. The safeguarding device according to claim 5, wherein the pressure connection channel is configured to couple at least the chamber with a vacuum-clamping device of a loading and/or unloading station that is configured at least for loading and/or unloading at least one wafer into/from a wafer transport container.

15. The safeguarding device according to claim 1, further comprising at least one emergency safeguarding and/or emergency release element, which is configured for a manual emergency safeguarding and/or manual emergency release of the safeguarding device.

16. The safeguarding device according to claim 15, further comprising at least one chamber, which comprises a pressure connection channel that is configured to allow a variation of an inner pressure in the chamber relative to a reference pressure, wherein a differential pressure is calculated from the inner pressure of the chamber and the reference pressure and is configured to influence a safeguarding status of the positive-fit unit, wherein the emergency safeguarding and/or emergency release element is arranged at least partly in the further chamber.

17. The safeguarding device according to claim 1, further comprising at least one status sensor, which is configured to sense a safeguarding status of the safeguarding device.

18. A wafer transport container with at least one safeguarding device according to claim 1, which is configured to prevent, in a safeguarding case, a complete removal of the wafer-transport-container opening element from a base body of the wafer transport container.

19. The wafer transport container according to claim 18, wherein the at least one safeguarding device is embodied integrally with the base body of the wafer transport container.

20. The wafer transport container according to claim 18, wherein the wafer transport container comprises at least one positive-fit recess, the positive-fit recess implementing a further pressure connection channel, which is configured for an evacuation of an additional further chamber of the safeguarding device.

21. A safeguarding system, in particular a vacuum safeguarding system, with at least one safeguarding device according to claim 1, with a wafer transport container, and with a loading and/or unloading station which is configured at least for loading and/or unloading wafers into/from the wafer transport container.

22. The safeguarding system according to claim 21, further comprising a vacuum pump unit, which is configured at least for a vacuum-clamping of the wafer transport container on the loading and/or unloading station in a loading and/or unloading position, and for varying an inner pressure in a chamber.

23. A method with a safeguarding device, in particular according to claim 1, with at least one positive-fit unit, wherein a wafer-transport-container opening element of the wafer transport container, which is held in its closure position by a closing mechanism, is safeguarded by means of the positive-fit unit.

24. The method according to claim 23, wherein a safeguarding of the positive-fit unit is realized by a variation of an inner pressure in a chamber of the safeguarding device.

25. The method according to claim 23, wherein, in a fault-free normal operation of the closing mechanism, the wafer-transport-container opening element is safeguarded by the positive-fit unit in a contact-free fashion, wherein, in case of a malfunction of the closing mechanism, a touch contact is established of the positive-fit unit, in particular of a positive-fit element of the positive-fit unit, with the wafer-transport-container opening element for the purpose of establishing a holding of the wafer-transport-container opening element in a proximity of the closure position.

Description

DRAWINGS

[0035] Further advantages will become apparent from the following description of the drawings. In the drawings an exemplary embodiment of the invention is illustrated. The drawings, the description and the claims contain a plurality of features in combination. Someone skilled in the art will purposefully also consider the features separately and will find further expedient combinations.

[0036] It is shown in:

[0037] FIG. 1 a schematic view of a safeguarding system according to the invention, with a safeguarding device according to the invention, with a wafer transport container and with a loading and/or unloading station,

[0038] FIG. 2 a schematic top view of the safeguarding system,

[0039] FIG. 3 a sectional view of the safeguarding system, with the safeguarding device in a safeguard state,

[0040] FIG. 4 a sectional view of the safeguarding system, with the safeguarding device in a non-safeguard state,

[0041] FIG. 5 a sectional view of the safeguarding device in a non-safeguard state brought about by an emergency safeguarding element and/or emergency release element of the safeguarding device, and

[0042] FIG. 6 a flow chart of a method according to the invention.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT

[0043] FIG. 1 shows a safeguarding system 56 with a safeguarding device. The safeguarding system 56 is implemented as a vacuum safeguarding system. The safeguarding device is implemented as a safeguarding device for a wafer transport container. The safeguarding device comprises three safeguarding modules 60 (cf. also FIG. 2). Alternatively the safeguarding device may comprise a number of safeguarding modules 60 that differs from three. The safeguarding system 56 comprises a wafer transport container 16. The wafer transport container 16 is configured for storage and/or transport of wafers 46. The wafer transport container 16 is configured for a transport of wafers 46 in a vacuum. The wafer transport container 16 is embodied in such a way that it is vacuum-tightly closable. The wafer transport container 16 is embodied as a vacuum wafer transport container.

[0044] The wafer transport container 16 comprises a base body 52. The base body 52 encompasses an interior of the wafer transport container 16 to a large extent. The base body 52 has an opening 62 (cf. FIG. 3). The wafers 46 stored in the wafer transport container 16 are retrievable out of the wafer transport container 16 and/or introducible into the wafer transport container 16 through the opening 62. The opening 62 has a diameter which is greater than a diameter of the wafers 46. The wafer transport container 16 comprises a wafer-transport-container opening element 14 (cf. FIG. 3). The wafer-transport-container opening element 14 is configured for closing the opening 62 of the wafer transport container 16. The wafer-transport-container opening element 14 is embodied in such a way that it is removable from the base body 52. The safeguarding device is configured to prevent in a safeguarding case a complete removal of the wafer-transport-container opening element 14 from the base body 52 of the wafer transport container 16.

[0045] The safeguarding system 56 comprises a loading and/or unloading station 44. The loading and/or unloading station 44 is configured for loading and/or unloading wafers 46 into and/or from the wafer transport container 16. For a loading and/or unloading of wafers 46, the loading and/or unloading station 44 opens the wafer transport container 16 by releasing the wafer-transport-container opening element 14 from the base body 52. To open the wafer transport container 16, the loading and/or unloading station 44 moves the wafer-transport-container opening element 14 in a loading and/or unloading direction 64. The loading and/or unloading direction 64 extends at least substantially perpendicularly to a main extension plane of the wafer-transport-container opening element 14. In opening, the wafer-transport-container opening element 14 is lowered into an interior of the loading and/or unloading station 44 by the loading and/or unloading station 44. In loading and/or unloading of the wafer transport container 16, an inner space of the base body 52 is vacuum-tightly connected to the inner space of the loading and/or unloading station 44. The loading and/or unloading station 44 is configured to transport wafers 46 unloaded from the wafer transport container 16 onward to at least one processing module (not shown) and/or at least one transfer module (not shown).

[0046] The safeguarding system 56 comprises a vacuum pump unit 58. The vacuum pump unit 58 is configured for a vacuum-clamping of the wafer transport container 16 on the loading and/or unloading station 44 in a loading and/or unloading position. The vacuum pump unit 58 comprises a vacuum pump 66. The vacuum pump unit 58 comprises a vacuum-clamping device 42. The vacuum pump 66 is configured to generate a negative pressure of the vacuum-clamping device 42. The vacuum-clamping device 42 is configured to fixedly hold, by way of the negative pressure, the wafer transport container 16 in the intended loading and/or unloading position relative to a surface 68 of the loading and/or unloading station 44.

[0047] FIG. 2 shows a top view of the safeguarding system 56. The vacuum-clamping device 42 comprises vacuum-clamping elements 70. The vacuum-clamping device 42 comprises corresponding vacuum-clamping elements 72. The vacuum-clamping elements 70 are arranged on the loading and/or unloading station 44. The vacuum-clamping elements 70 are embodied as channel-like deepenings in the surface 68 of the loading and/or unloading station 44. The corresponding vacuum-clamping elements 72 are arranged on the wafer transport container 16. The corresponding vacuum-clamping elements 72 are embodied as ear-shaped flat bulges protruding horizontally from the base body 52. In the loading and/or unloading position the corresponding vacuum-clamping elements 72 cover the vacuum-clamping elements 70 completely. In vacuum-clamping, the vacuum pump unit 58 creates a negative pressure between the vacuum-clamping elements 70, 72, resulting in pressure forces caused by the ambient pressure pressing the corresponding vacuum-clamping elements 72 onto the vacuum-clamping elements 70. Due to the negative pressure between the vacuum-clamping elements 70, 72, the base body 52 is firmly pressed onto the surface 68 of the loading and/or unloading station 44.

[0048] The safeguarding system 66 comprises an alignment mechanism 74. The orientation mechanism 74 is configured to align the wafer transport container 16 with respect to the loading and/or unloading station 44. The alignment mechanism 74 comprises a plurality of projections 76, which are embodied in a bolt-like fashion. The projections 76 are arranged on the base body 52 of the wafer transport container 16. The alignment mechanism 74 comprises a plurality of hollows 78, each of them being configured to accommodate a respective projection 76. The hollows 78 are arranged in the surface 68 of the loading and/or unloading station 44.

[0049] FIG. 3 shows a section through the safeguarding system 56 along a sectional plane which extends centrally through the safeguarding module 60 and is given the reference sign A in FIG. 2. In the situation shown in FIG. 3, the wafer transport container 16 and the loading and/or unloading station 44 are in a non-coupled state. In the situation shown in FIG. 3, the safeguarding device is in a safeguard state. The wafer transport container 16 comprises a closing mechanism 12. The closing mechanism 12 is configured to hold the wafer-transport-container opening element 14 in a closure position. The closing mechanism 12 is embodied as a vacuum closing mechanism. In the closure position the wafer-transport-container opening element 14 closes the opening 62 of the base body 52 of the wafer transport container 16. As a result of a vacuum in the inner space of the wafer transport container 16, the wafer-transport-container opening element 14 is pressed against the base body 52 of the wafer transport container 16 by external pressure forces. The closing mechanism 12 comprises a sealing element 80. The sealing element 80 of the closing mechanism 12 is configured to seal the closing mechanism 12 at least substantially in a gas-tight manner. The sealing element 80 of the closing mechanism 12 is embodied as an O-ring. Alternatively or additionally the sealing element 80 of the closing mechanism 12 could comprise a lip seal and/or a vulcanized seal.

[0050] The safeguarding device comprises a positive-fit unit 10. The positive-fit unit 10 is configured for a safeguarding of the wafer-transport-container opening element 14 of the wafer transport container 16, which is held in its closure position by the closing mechanism 12.

[0051] The positive-fit unit 10 comprises a positive-fit recess 18. The positive-fit recess 18 is configured to partially accommodate a positive-fit element 20 of the positive-fit unit 10. The positive-fit recess 18 is implemented as a groove in the wafer-transport-container opening element 14. Alternatively the positive-fit recess 18 could feature any other shape, preferably a shape adapted to a shape of the positive-fit element 20. In a coupled state of the wafer transport container 16 with the loading and/or unloading station 44, the positive-fit recess 18 is open towards the inner space of the loading and/or unloading station 44. The positive-fit unit 10 comprises the positive-fit element 20. The positive-fit element 20 is configured to partially engage in the positive-fit recess 18. The positive-fit element 20 is partly embodied as a rod-shaped locking bar. The positive-fit recess 18 and the positive-fit element 20 are configured to couple with one another in a contact-free manner in case of a proper safeguarding. The positive-fit recess 18 and the positive-fit element 20 are configured to couple with one another in a contacting manner in case of an unintended failure of the closing mechanism 12.

[0052] The safeguarding module 60 comprises a module base body 82. The module base body 82 forms a portion of an outer delimitation of the safeguarding module 60. The positive-fit element 20 is arranged partially within the module base body 82. The positive-fit element 20 is partly encompassed by the module base body 82. The module base body 82 comprises an opening 84. The positive-fit element 20 partly extends through the opening 84 of the module base body 82. The positive-fit element 20 is free of a contact with the opening 84 of the module base body 82. In this way, in case of a movement of the positive-fit element 20 a particle generation may be advantageously kept at a low level.

[0053] The safeguarding device is partially embodied integrally with the wafer transport container 16. The safeguarding device is embodied integrally with the base body 52 of the wafer transport container 16. The module base body 82 is embodied integrally with the base body 52 of the wafer transport container 16. The positive-fit element 20 is supported in such a way that it is movable relative to the module base body 82. The safeguarding device comprises a guide element 90. The guide element 90 is configured to guide a movement of the positive-fit element 20. The guide element 90 is embodied as a rounded guide rod. The guide element 90 and the positive-fit element 20 are embodied integrally with one another.

[0054] The safeguarding device comprises a linear bearing 40. The linear bearing 40 is configured to permit a translational movement of the positive-fit unit 10. The linear bearing 40 is configured to permit a translational movement of the positive-fit element 20. The linear bearing 40 comprises two bearing elements 86, 88. The bearing elements 86, 88 are implemented as slide bearings. The bearing elements 86, 88 form slide bushings. In a movement of the positive-fit element 20, the bearing elements 86, 88 remain stationary relative to the wafer transport container 16. The bearing elements 86, 88 are implemented of a plastic material or of a plastic-coated metal. Alternatively the linear bearing 40 could comprise a number of bearing elements 86, 88 that differs from two, e.g. one bearing element 86, 88 or three bearing elements 86, 88. Furthermore the linear bearing 40 could alternatively or additionally comprise at least one ball bearing. Moreover the positive-fit element 20, in particular the guide element 90, could also be embodied integrally with the linear bearing 40, for example in such a way that at least the guide element 90 comprises a slide surface, which is in particular realized by a coating.

[0055] The safeguarding device comprises a chamber 24. The chamber 24 forms a hollow space in an interior of the safeguarding module 60. The chamber 24 comprises a pressure connection channel 26. The pressure connection channel 26 is configured for coupling the chamber 24 with the vacuum-clamping device 42. The vacuum-clamping device 42 comprises a suction channel 100. The suction channel 100 is fluidically connected to the vacuum pump 66. In a coupling of the pressure connection channel 26 with the vacuum-clamping device 42, the suction channel 100 is gas-tightly connected to the pressure connection channel 26. The connection of the pressure connection channel 26 to the suction channel 100 is implemented free of coupling elements and flexible tubes, exclusively by tight abutment of the safeguarding module 60 on the surface 68 of the loading and/or unloading station 44.

[0056] With the exception of the pressure connection channel 26, the chamber 24 is implemented in such a way that it is sealed off from the environment in a gas-tight manner. The chamber 24 has an inner volume 34. The pressure connection channel 26 is configured to permit a variation of an inner pressure in the chamber 24 relative to a reference pressure. The pressure connection channel 26 forms a connection element for the vacuum pump unit 58. It is possible to evacuate the chamber 24 by means of the pressure connection channel 26. The pressure connection channel 26 is implemented as a bore in a chamber wall 28 of the chamber 24. The pressure connection channel 26 is arranged on an underside of the safeguarding module 60. The pressure connection channel 26 extends in a direction which is, in a state when the wafer transport container 16 is coupled with the base body 52 of the wafer transport container 16, at least substantially perpendicular to a main extension plane of the wafer-transport-container opening element 14. The pressure connection channel 26 is in a safeguard state and in a non-safeguard state open towards the chamber 24. The chamber walls 28 delimiting the chamber 24 are embodied separately from the module base body 82. The chamber walls 28 delimiting the chamber 24 are screwed with the module base body 82. This advantageously allows for simple assembly and/or maintenance of the safeguarding module 60. The chamber walls 28 delimiting the chamber 24 are embodied to be non-destructively demountable. Alternatively at least a portion of the chamber walls 28 delimiting the chamber 24 could be embodied integrally with the wafer transport container 16.

[0057] A difference between the inner pressure of the chamber 24 and the reference pressure constitutes a differential pressure. The differential pressure is implemented for influencing a safeguarding status of the positive-fit unit 10. A position of the positive-fit element 20 with respect to an immobile chamber wall 28 of the chamber 24 depends on the differential pressure. The positive-fit unit 10 is configured to take a non-safeguard position if the differential pressure exceeds a limit differential pressure. The positive-fit element 20 is not in engagement with the positive-fit recess 18 if the differential pressure is below a limit differential pressure. The positive-fit unit 10 is configured to take a safeguarding position if the differential pressure is below the limit differential pressure. The positive-fit element 20 is in engagement with the positive-fit recess 18 if the differential pressure exceeds the limit differential pressure. The limit differential pressure is realized as a limit value of the differential pressure.

[0058] The safeguarding device comprises a reset element 22. The reset element 22 is configured to re-deflect the positive-fit unit 10 into a safeguarding position. The reset element 22 is configured to hold the positive-fit unit 10 in the safeguarding position. The reset element 22 is embodied as a compression spring. A reset force of the reset element 22 acts in a direction that runs in parallel to a main extension direction of the positive-fit element 20. By a main extension direction of an object is herein in particular a direction to be understood which extends in parallel to a longest edge of a smallest geometric rectangular cuboid just still completely enclosing the object. The reset force of the reset element 22 acts at least indirectly onto the positive-fit element 20. The reset force of the reset element 22 presses the positive-fit element 20 into a safeguarding position. The reset element 22 is arranged within the chamber 24. The reset element 22 abuts on an inner face of a chamber wall 28 that faces away from the wafer transport container 16. The reset element 22 partly engages around the guide element 90. The chamber wall 28 facing away from the wafer transport container 16 comprises a protrusion 92. The protrusion 92 is implemented in a cylindrical shape. The protrusion 92 is configured to partly accommodate the reset element 22. The protrusion 92 is configured to advantageously prevent a slipping of the reset element 22, for example in case of a movement of the wafer transport container 16.

[0059] The safeguarding device comprises a further chamber 30. The further chamber 30 has an inner volume 36. In a safeguard state of the safeguarding device and in a non-safeguard state of the safeguarding device, the further chamber 30 has an inner pressure that is identical to an ambient pressure. The ambient pressure is implemented as an atmospheric pressure or as a cleanroom atmospheric pressure. Viewed from the wafer transport container 16, the further chamber 30 is arranged before the chamber 24. The guide element 90 is arranged within the further chamber 30. The linear bearing 40 is arranged within the further chamber 30. The safeguarding device comprises a movably supported setting element 32. The movably supported setting element 32 is embodied as a movable piston. The movably supported setting element 32 partially delimits the chamber 24. The movably supported setting element 32 partially delimits the further chamber 30. The chamber 24 and the further chamber 30 are gastightly sealed against each other by means of the movably supported setting element 32. The movably supported setting element 32 comprises a sealing element 94. The sealing element 94 of the movably supported setting element 32 is embodied as an O-ring. Alternatively or additionally the sealing element 94 of the movably supported setting element 32 could comprise a lip seal and/or a vulcanized seal.

[0060] The guide element 90 is guided through the movably supported setting element 32. The guide element 90 is fixedly connected to the movably supported setting element 32 via a fixation device 98. The fixation device 98 comprises a Benzing retaining ring. Alternatively or additionally the fixation device 98 may comprise a Seeger retaining ring, a safety wiring and/or a screwing. The movably supported setting element 32 comprises a further sealing element 96. The further sealing element 96 of the movably supported setting element 32 is configured for sealing off the pass-through for the guide element 90 against the chamber 24 in a gastight manner. The further sealing element 96 of the movably supported setting element 32 is embodied as an O-ring. Alternatively or additionally the further sealing element 96 of the movably supported setting element 32 could comprise a lip seal and/or a vulcanized seal. The movably supported setting element 32 is configured for varying the inner volume 34 of the chamber 24 depending on a pressure difference of the inner pressures of the chamber 24 and the further chamber 30. The movably supported setting element 32 is configured for varying the inner volume 36 of the further chamber 30 depending on the pressure difference of the inner pressures of the chamber 24 and the further chamber 30.

[0061] The safeguarding device comprises a status sensor 50. The status sensor 50 is configured to sense a safeguarding status of the safeguarding device. The status sensor 50 is allocated to the loading and/or unloading station 44. The status sensor 50 is configured to communicate a safeguarding status of the safeguarding device to the loading and/or unloading station 44. In this way it is advantageously possible to prevent initiation of an opening process for opening the wafer-transport-container opening element 14 by the loading and/or unloading station 44 while a safeguarding of the safeguarding device, in particular of the positive-fit unit 10, is still active, such that damages to the wafer transport container 16 may advantageously be avoided. The status sensor 50 comprises a magnet sensor, which is capable of capturing a movement and/or a position of a component of the safeguarding module 60, in particular of the guide element 90 and/or of the positive-fit element 20.

[0062] The safeguarding device comprises an additional further chamber 38. The additional further chamber 38 is configured to have in at least one operating state an inner pressure differing from the ambient pressure. Viewed from the wafer transport container 16, the additional further chamber 38 is arranged before the further chamber 30. Viewed from the wafer transport container 16, the additional further chamber 38 is arranged before the chamber 24. The additional further chamber 38 is gas-tightly sealed against the further chamber 30. The safeguarding device comprises an additional sealing element 102. The additional sealing element 102 of the safeguarding device is configured to gas-tightly insulate the further chamber 30 and the additional further chamber 38 from each other in a gastight manner. The additional sealing element 102 of the safeguarding device is embodied to be compressible. The additional sealing element 102 of the safeguarding device is configured for being compressed and/or expanded upon a movement of the positive-fit element 20 and/or of the guide element 90. The safeguarding device comprises a transfer element 104. The transfer element 104 is configured to transfer a movement of the guide element 90 and/or of the positive-fit element 20 onto the additional sealing element 102 of the safeguarding device. The transfer element 104 is embodied integrally with the guide element 90. The transfer element 104 is embodied integrally with the positive-fit element 20. The additional sealing element 102 of the safeguarding device is embodied as a edge-welded bellows element. The edge-welded bellows element is made of metal. The positive-fit element 20 is partially arranged in the additional further chamber 38. The additional further chamber 38 is embodied in such a way that it is open to an outside by the opening 84 of the module base body 82. In a non-coupled state of the wafer transport container 16, the inner pressure in the additional further chamber 38 is identical to the ambient pressure.

[0063] FIG. 4 shows, like FIG. 3, a section through the safeguarding system 56 along the sectional plane which extends centrally through the safeguarding module 60 and is given the reference sign A in FIG. 2. In the situation shown in FIG. 4, the wafer transport container 16 and the loading and/or unloading station 44 are in a coupled state. In the situation shown in FIG. 4, the safeguarding device is in a non-safeguard state. In the non-safeguard state the chamber 24 is evacuated via the pressure connection channel 26, as a result of which the movably supported setting element 32 is pushed in a direction away from the wafer transport container 16. Due to this, the inner volume 34 of the chamber 24 is reduced and an inner volume 130 of the additional further chamber 38 is increased. Moreover, the positive-fit element 20 is for this reason arranged in such a way that it is to a large extent retracted into the additional further chamber 38. The additional sealing element 102 of the safeguarding device is compressed.

[0064] The positive-fit recess 18 implemented in the wafer transport container 16 forms a further pressure connection channel 54. The further pressure connection channel 54 is configured for evacuating the additional further chamber 38 of the safeguarding device. The possibility of an evacuation of the additional further chamber 38 by the further pressure connection channel 54 is restricted to the state when the wafer transport container 16 is coupled with the loading and/or unloading station 44. In the coupled state of the wafer transport container 16 with the loading and/or unloading station 44, the pressure connection channel 54 implements a connection of the additional further chamber 38 to a gas-tightly insulated interstice 106 between an underside of the wafer-transport-container opening element 14 and an upper side of the loading and/or unloading station 44. An inner pressure in the interstice 106 is coupled with the inner pressure in the chamber 24. The inner pressure in the chamber 24 and the inner pressure in the interstice 106, and thus the inner pressure in the additional further chamber 38 as well, are generated by the vacuum pump 66 of the vacuum pump unit 58. The vacuum pump unit 58 is configured for varying the inner pressure in the chamber 24.

[0065] The safeguarding device comprises an emergency safeguarding and/or emergency release element 48. The emergency safeguarding and/or emergency release element 48 is configured for a manual emergency safeguarding and/or for a manual emergency release of the safeguarding device. The emergency safeguarding and/or emergency release element 48 is arranged at least partially in the further chamber 30. The emergency safeguarding and/or emergency release element 48 is movably supported in the further chamber 30. For an emergency release, an operator pulls the emergency safeguarding and/or emergency release element 48 out of the further chamber 30. The emergency safeguarding and/or emergency release element 48 is embodied as a pull-out lever protruding from the safeguarding module 60.

[0066] FIG. 5 shows another section through the safeguarding system 56 along another sectional plane, which extends through the safeguarding module 60 and is indicated with the reference sign B in FIG. 2. In the situation illustrated in FIG. 5, the safety element of the safeguarding device has been released via the emergency safeguarding and/or emergency release element 48. The emergency safeguarding and/or emergency release element 48 is configured to displace, in an emergency release, the movably supported setting element 32 towards the chamber 24. The emergency safeguarding and/or emergency release element 48 is configured to push, in an emergency release, the positive-fit element 20 towards the chamber 24. The emergency safeguarding and/or emergency release element 48 is configured to undo, in an emergency release, the engagement of the positive-fit element 20 with the positive-fit recess 18. The emergency safeguarding and/or emergency release element 48 comprises a cam mechanism 108. The cam mechanism 108 is configured to convert a movement of the emergency safeguarding and/or emergency release element 48 into a movement of the movably supported setting element 32 and/or of the positive-fit element 20 perpendicularly to the movement of the emergency safeguarding and/or emergency release element 48. The cam mechanism 108 comprises a slope 110 and a pin 112. The slope 110 is arranged on the emergency safeguarding and/or emergency release element 48. The slope 110 connects a point of the emergency safeguarding and/or emergency release element 48 that has a small material thickness to a point of the emergency safeguarding and/or emergency release element 48 that has a greater material thickness. The pin 112 is arranged on the movably supported setting element 32. In a safeguard state of the safeguarding device, the pin 112 abuts on the point of the emergency safeguarding and/or emergency release element 48 that has a low material thickness. When the emergency safeguarding and/or emergency release element 48 is pulled out in a vertical direction, the slope 110 moves along the pin 112, which is immobile in the vertical direction. The material thickness of the emergency safeguarding and/or emergency release element 48 increases along the slope 110, and the pin 112 is therefore necessarily deflected horizontally. In a state of emergency release of the safeguarding device, the pin 112 abuts on the point of the emergency safeguarding and/or emergency release element 48 that has a greater material thickness. When the emergency safeguarding and/or emergency release element 48 is then moved back into the further chamber 30, the reset element 22 deflects the movably supported setting element 32 and/or the positive-fit element 20 back into the original position of the safeguard state.

[0067] FIG. 6 shows a flow chart of a method with the safeguarding device. In at least one method step 114 the wafer transport container 16 is transported and/or stored. During said transport and/or during said storage, in at least one method step 116 the wafer-transport-container opening element 14, which is held in its closure position by means of the closing mechanism 12, is safeguarded by the positive-fit unit 10. In a fault-free normal operation of the closing mechanism 12, in at least one method step 120 the wafer-transport-container opening element 14 is safeguarded by the positive-fit unit 10 in a touch-free manner. In case of a malfunction of the closing mechanism 12, in at least one method step 118 a touch contact of the positive-fit unit 10 with the wafer-transport-container opening element 14 is established. Herein the touch contact of the positive-fit unit 10 with the wafer-transport-container opening element 14 is established to ensure a holding of the wafer-transport-container opening element 14 in a proximity of the closure position. In at least one method step 122, the wafer transport container 16 is coupled with the loading and/or unloading station 44. In at least one method step 124 a safeguarding and/or release of the positive-fit unit 10 is generated via a variation of an inner pressure in the chamber 24 of the safeguarding device. For the purpose of safeguarding the wafer-transport-container opening element 14, in at least one method step 128 the positive-fit element 20 is moved into a safeguard position by reduction of the differential pressure between the chamber 24 and the further chamber 30. For the purpose of a release of the safeguarding of the wafer-transport-container opening element 14, in at least one method step 126 the positive-fit element 20 is moved into a non-safeguard position by an increase of the differential pressure between the chamber 24 and the further chamber 30.

REFERENCE NUMERALS

[0068] 10 positive-fit unit [0069] 12 closing mechanism [0070] 14 wafer-transport-container opening element [0071] 16 wafer transport container [0072] 18 positive-fit recess [0073] 20 positive-fit element [0074] 22 reset element [0075] 24 chamber [0076] 26 pressure connection channel [0077] 28 chamber wall [0078] 30 further chamber [0079] 32 setting element [0080] 34 inner volume [0081] 36 inner volume [0082] 38 additional further chamber [0083] 40 linear bearing [0084] 42 vacuum-clamping device [0085] 44 loading and/or unloading station [0086] 46 wafer [0087] 48 emergency safeguarding and/or emergency release element [0088] 50 status sensor [0089] 52 base body [0090] 54 further pressure connection channel [0091] 56 safeguarding system [0092] 58 vacuum pump unit [0093] 60 safeguarding module [0094] 62 opening [0095] 64 loading and/or unloading direction [0096] 66 vacuum pump [0097] 68 surface [0098] 70 vacuum-clamping element [0099] 72 corresponding vacuum-clamping element [0100] 74 alignment mechanism [0101] 76 projection [0102] 78 hollow [0103] 80 sealing element [0104] 82 module base body [0105] 84 opening [0106] 86 bearing element [0107] 88 bearing element [0108] 90 guide element [0109] 92 protrusion [0110] 94 sealing element [0111] 96 further sealing element [0112] 98 fixation device [0113] 100 suction channel [0114] 102 additional sealing element [0115] 104 transfer element [0116] 106 interstice [0117] 108 cam mechanism [0118] 110 slope [0119] 112 pin [0120] 114 method step [0121] 116 method step [0122] 118 method step [0123] 120 method step [0124] 122 method step [0125] 124 method step [0126] 126 method step [0127] 128 method step [0128] 130 inner volume [0129] A section plane [0130] B section plane