Vibration isolator with coil spring and actuator

Abstract

The present invention generally relates to an active vibration isolator with a coil spring acting in a vertical direction. The invention further relates to an active vibration damping method of a load to be supported, such as a machine, equipment or instrument to be supported. To this end, a vibration isolator is proposed, comprising an inner shell, which has a cavity for receiving and holding a coil spring, which is arranged in the cavity of the inner shell and acts in the vertical direction, and an outer shell, which surrounds the inner shell at least in sections. An actuator acting in the vertical direction is arranged between the inner housing and the outer housing.

Description

Technical Field

[0001] The present invention generally relates to an active vibration isolator with a helical spring acting in a vertical direction. In particular, the present invention relates to a vibration isolator that can be used in a standing wave vibration isolation system for supporting a machine, system or instrument, in particular in the field of semiconductor industry, such as a system or instrument in the field of photolithography, optical inspection equipment or wafer processing equipment. In addition, the present invention also relates to a method for active vibration reduction of a supported load, such as a supported machine, system or instrument. Background Art

[0002] Vibration isolation systems with mechanical springs, for example coil springs, are known. In such systems, the load to be isolated from the ground, for example in a lithography field system, is supported on three or more isolators acting at least in a vertical direction. Mechanical coil springs enable very simple passive vibration isolation, especially in the case of relatively large or heavy loads. Vibration isolation can be achieved above the natural frequency of the spring-mass system.

[0003] By designing the vibration isolation system as an active vibration isolation system, the vibration isolation effect of the vibration isolation system can be improved, in particular when such vibration isolation systems are used to support sensitive machines, such as in the semiconductor industry.

[0004] The mechanical spring systems used are designed for the weight of the load to be supported. This is necessary because the mechanical springs no longer behave linearly within the load limit range, so that the damping characteristics become unfavorable. In addition, the vibration isolators may also be damaged.

[0005] Since the deflection of the coil spring is substantially linearly related to the force within a predetermined load range, it can be understood that the height of the vibration isolation load varies with its weight.

[0006] In order to compensate for changes in the vibration isolation load or uneven force distribution, it is known that such mechanical spring systems have a height correction function. This can be achieved very simply, for example, by arranging the vibration isolation system in a static position through a height-adjustable spring seat. Such a mechanical vibration isolator can be found in the patent document EP2750738A1 of the applicant.

[0007] However, in all cases, when adjusting the height of such a mechanical spring system, a torque may be generated, which may result in a horizontal force. This horizontal force component usually causes an undesirable horizontal displacement of the load on the isolation support or the isolator itself. In active vibration isolation systems, horizontal displacement is particularly undesirable because it may cause the opposing parts of the non-contact actuator to move relative to each other.

[0008] In magnetic actuators, for example, this can lead to changes in the gap size between the associated magnets, which can have a negative impact on performance and can damage the magnets. To avoid this, the actuator is designed as a separate component and is spatially separated from the vibration isolator so that any damage can be reliably excluded when adjusting the mechanical spring system, for example.

[0009] Therefore, patent document EP3181944A1 proposes another spring system based on a pneumatic spring.

[0010] However, such pneumatic vibration isolation systems also have other disadvantages, for example if the load to be isolated exhibits a high moving mass and / or exerts a high acceleration of the moving mass on the system. In this case, large forces are required and the pneumatic springs require corresponding installation space. However, the construction and operation of such pneumatic springs are more complicated than coil springs.

[0011] In view of the above, there is a need for a vibration isolator that does not have the above-mentioned disadvantages.

[0012] The installation space of the vibration isolator should be as small as possible to enable flexible use.

[0013] The vibration isolator should also be suitable for higher loads, in particular loads weighing more than 500 kg, preferably more than 1000 kg. Summary of the invention

[0014] This object was undertaken by the present inventors.

[0015] In order to achieve the above technical objectives, the inventor of the present application unexpectedly proposed a vibration isolator and a vibration reduction method according to the independent claims. The preferred embodiments and improved solutions of the present invention can be found in the dependent claims.

[0016] The subject of the invention is therefore a vibration isolator comprising:

[0017] an inner housing having a cavity for receiving and retaining the coil spring,

[0018] The coil spring is arranged in the cavity of the inner shell and acts in a vertical direction;

[0019] an outer shell at least partially surrounding the inner shell; and

[0020] The actuator acts in a vertical direction and is arranged at least in sections between the inner shell and the outer shell.

[0021] The vibration isolators may be part of a statically constructed vibration isolation system that may be used, for example, to support instrumentation in the semiconductor industry.

[0022] Such a vibration isolation system may, for example, comprise a vibration-isolatingly supported table or frame on which the corresponding instrument is mounted. In the context of the present invention, "horizontal" and "vertical" shall refer to the main directions of the vibration isolator in the installed state.

[0023] For a coil spring, the vertical direction corresponds to the central axis direction of the coil spring in the working state, i.e. the axial direction. The vibration isolator acts in this direction.

[0024] In order to connect the vibration isolator to the ground, the housing can be configured with a corresponding fastening mechanism to establish a stable connection with the ground. For this purpose, for example, a threaded connection can be provided to connect the vibration isolator to a corresponding receiving portion on the ground in a fixed and detachable manner.

[0025] The outer shell may at least partially accommodate the inner shell in its interior. According to a preferred embodiment of the present invention, the outer shell may surround the inner shell along an outer wall of the inner shell, so that the inner wall of the outer shell and the outer wall of the inner shell are opposite to each other.

[0026] The outer shell and the inner shell can be cylindrical, which is conducive to uniform force distribution and vibration isolation. In this case, the outer shell and the inner shell and the spiral spring are advantageously arranged coaxially with each other.

[0027] In a preferred embodiment of the present invention, the outer shell and the inner shell are also rigidly connected to each other in the horizontal direction. In order to achieve the movement required for vibration isolation, preferably, the inner shell can move in the vertical direction inside the outer shell. In other words, the inner shell with the coil spring can move in the axial or vertical direction relative to the outer shell, but is rigidly connected to the outer shell in the radial or horizontal direction.

[0028] The horizontal rigid connection of the inner shell can be realized by at least one spring element, preferably at least one leaf spring, which is parallel to the actuator. The leaf spring can be arranged in the working space of the vibration isolator and connects the inner shell to the outer shell.

[0029] Preferably, the vibration isolator comprises at least two leaf springs spaced apart from one another in the axial direction, so that a tilting of the inner shell relative to the outer shell can be particularly well compensated and a rigid connection in the horizontal direction can be ensured.

[0030] The leaf spring can be part of a leaf spring package. For example, a segmented leaf spring constructed from ring segments is conceivable. A particularly preferred embodiment provides that two leaf spring packages are arranged axially spaced apart from each other, approximately in the region of the end faces of the inner shell and the outer shell.

[0031] This allows the leaf springs to be arranged interchangeably. The natural frequency of the vibration isolator can thus be easily adjusted by replacing the spring assembly and thus adapted to different load situations. In particular, natural frequencies of more than 5 Hz can be achieved in order to shorten the stabilization time.

[0032] In a preferred embodiment of the present invention, the coil spring is mechanically rigidly coupled to the inner housing in the horizontal direction and is therefore isolated in the vertical direction. The inner housing can be configured to accommodate and retain the coil spring using a suitable mechanism, such as a spring seat ring, which allows the coil spring to be fixed in place in the horizontal and vertical directions.

[0033] According to the invention, an actuator is provided which acts in the vertical direction and can be arranged in the working space of the vibration isolator. This makes it possible to introduce the forces into the vibration isolator particularly uniformly and to optimize the space utilization.

[0034] In a particularly preferred embodiment of the present invention, the actuator is configured as a magnetic actuator, comprising at least one coil and a magnet, forming a magnet-coil pair. The coil and the magnet can be arranged between the inner shell and the outer shell, for which a corresponding cavity or working space can be provided. The working space can, for example, include a groove on the inner wall of the outer shell and / or a groove on the outer wall of the inner shell.

[0035] In addition to the coil spring, the actuator can also achieve additional vibration isolation in the vertical direction. The actuator is particularly used for active vibration isolation. Therefore, the vibration isolator of the present invention can also be called an active vibration isolator.

[0036] In a preferred embodiment, at least one magnet coil pair at least partially surrounds the helical spring. In other words, the coil and / or the magnet are at least partially arranged around the helical spring.

[0037] In a particularly preferred embodiment, at least one magnet coil pair is annular or is constructed based on annular segments. In this way, the helical spring can be partially or preferably completely surrounded. In this way, the force applied to the vibration isolator by the actuator can be particularly uniform. In particular, in this way, a tilting movement of the inner shell due to uneven unilateral force application by the actuator can be prevented.

[0038] In a preferred embodiment, at least one coil of the actuator extends around the inner housing and is therefore arranged on the outer wall of the inner housing. For example, at least one coil can be pressed or glued onto the inner housing. An associated magnet, in particular a permanent magnet, can be assigned to the outer housing and extend on the inner wall. It can also be glued on likewise.

[0039] Preferably, the magnet and the associated coil are arranged opposite one another, with a gap being present between the magnet and the coil.

[0040] Since the inner shell and the outer shell are rigidly connected in the horizontal direction, the gap can be constructed to be extremely narrow, for example, the width in the radial direction is less than 5 mm, preferably less than 1 mm, and particularly preferably less than 0.5 mm. In this way, the working space can be made correspondingly smaller, so that the vibration isolator as a whole remains compact, and a relatively high force can be generated.

[0041] In other embodiments, the opposite arrangement may also be provided, that is, the magnet is arranged on the outer wall of the inner shell, and the coil is arranged on the inner wall of the outer shell.

[0042] According to a preferred embodiment, the vibration isolator comprises a plurality of actuators, preferably magnetic actuators, juxtaposed to each other in the axial direction. In one embodiment, the vibration isolator comprises at least two or more preferably three or more actuators, especially magnetic actuators, juxtaposed to each other. This allows a greater force to be generated in a compact installation space.

[0043] Preferably, the current flows in opposite directions through the magnet coil pairs juxtaposed to each other. To this end, the winding directions of adjacent coils and the magnet magnetization directions between adjacent magnet coil pairs are preferably arranged alternately.

[0044] In order to use an odd number of magnet coil pairs (e.g., three magnet coil pairs) to apply force uniformly over the length range, the size of the middle magnet coil pair can be larger than the size of the outer magnet coil pair, so as to achieve a higher force under the same current. This structure is conducive to reducing the magnetic field saturation between different magnet groups, and ultimately increasing the magnetic induction intensity (B) in the coil gap.

[0045] For this purpose, the number of coil windings of the central magnet coil pair may be, for example, twice the number of coil windings of the two outer magnet coil pairs.

[0046] The outer magnet coil pair may have the same coil winding array, which makes it particularly easy to form two adjacent magnetic fields in the axial direction, through which the vertical movement of the inner shell relative to the outer shell can be achieved.

[0047] In the axial direction, the distance between adjacent magnet coil pairs may be about 1 mm to 5 mm, with a magnetic shield disposed therebetween.

[0048] In a preferred embodiment, the isolator further comprises an insert for receiving the load, preferably an elongated insert. The insert may extend at least partially into the helical spring. The insert may be fixedly connected to the inner shell at the upper end and include an upper receiving portion for receiving the helical spring, such as an upper spring seat. In another embodiment, the insert may also be configured as a part of the inner shell.

[0049] The insert can be designed to have a cavity which is open upward and can be used to accommodate a load, at least in sections in the region protruding into the coil spring. In the lower region of the cavity, the load receiver can be fixedly connected to the bottom region of the insert in the axial direction and in the radial direction. The load receiver is thus held on the bottom of the insert, while in the upper region it is freely arranged in the cavity and can therefore be displaced in the radial direction or in the horizontal direction.

[0050] Particularly advantageously, the load receiving part can be designed as a bent rod or an articulated pendulum and the upper end of the load receiving part can be connected to the load to be isolated. For this purpose, a suitable receiving part can be provided. Thus, forces acting on the load to be isolated in the horizontal direction can be absorbed via the load receiving part.

[0051] In another aspect, the invention relates to a method for isolating a load to be supported, in which at least one vibration isolator according to the invention as described above is used.

[0052] The method provides that a sensor is arranged on the load to be isolated and / or on the ground, so that at least one actuator of the vibration isolator can be triggered via a control circuit to actively counteract any vibrations that may occur. For example, the sensor can be designed as a motion sensor or an acceleration sensor.

[0053] In a further aspect, the present invention relates to an instrument, in particular a lithography apparatus or photolithography device, an optical inspection apparatus, a wafer or substrate processing apparatus or device, wherein the instrument comprises at least one vibration isolator as described above for vibration isolation. In a preferred embodiment, such an instrument may comprise at least three such vibration isolators for three-point mounting.

[0054] It is also conceivable that two such vibration isolators can operate together, wherein the two vibration isolators are arranged at 90° to each other, so that active vibration isolation can be achieved in both a first direction (eg, vertical direction) and a second direction (eg, horizontal direction).

[0055] The vibration isolator of the present invention is characterized in that it requires a small installation space and is therefore very flexible to use.

[0056] Furthermore, the vibration isolator of the present invention can also be used for heavier loads, in particular for loads having a weight of more than 500 kg, such as more than 1000 kg or even more than 1500 kg.

[0057] More details of the present invention can be found in the following specific embodiments and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 An embodiment of the vibration isolator of the present invention is shown in cross section;

[0059] Figure 2 The oblique view shows Figure 1 The vibration isolator shown;

[0060] Figure 3 The vibration isolation system is schematically shown in side view;

[0061] Figure 4 The cross-sectional oblique view shows Figure 2 The vibration isolator shown;

[0062] Figure 5The side wall of the vibration isolator of the present invention is shown in cross section;

[0063] Figure 6 Shows Figure 5 The magnetic field generated by the sidewall region during operation is shown. DETAILED DESCRIPTION

[0064] In the following detailed description of the preferred embodiments, for the sake of clarity, the same reference numerals represent substantially the same parts in these embodiments. However, in order to more clearly illustrate the present invention, the preferred embodiments shown in the drawings are not all drawn to scale.

[0065] Figure 1 A cross-sectional view of an embodiment of a vibration isolator 10 of the present invention is shown.

[0066] The vibration isolator 10 shown in the figure comprises:

[0067] The inner housing 20 has a cavity 21 for accommodating and retaining the coil spring 50.

[0068] The coil spring 50 is arranged in the cavity 21 of the inner housing 20 and acts in the vertical direction;

[0069] an outer shell 30 at least partially surrounding the inner shell 20; and

[0070] The actuator 40 , which acts in a vertical direction, is arranged between the inner housing 20 and the outer housing 30 .

[0071] The vibration isolator 10 is part of a statically constructed vibration isolation system 1 which can be used, for example, for supporting devices in the semiconductor industry.

[0072] Such a vibration isolation system 1 can, for example, comprise a table 4 or a frame mounted in a vibration-isolating manner, on which a corresponding instrument, for example a scanning electron microscope 5 , is mounted. Figure 3 The vibration isolation system 1 is shown purely schematically in a side view. The table 4 and the device 5 located thereon as the load to be supported can be isolated relative to the ground 2 by vibration isolators 10. In the present exemplary embodiment, a total of four such vibration isolators 10 are provided.

[0073] In order to connect the vibration isolator 10 to the ground, the housing 30 can be configured with corresponding fastening mechanisms to establish a stable connection with the ground or the receiving plate 3. For this purpose, for example, a threaded connection 31 can be provided to connect the vibration isolator to, for example, a corresponding receiving portion in a fixed and detachable manner.

[0074] The outer shell 30 can accommodate the inner shell 20 at least in sections or at least partially in its interior, and for this purpose a cavity is also formed, which is also referred to as a working space 32 in the following text.

[0075] In the embodiment shown, the outer shell 30 almost completely surrounds the inner shell 20, so that the inner wall 33 of the outer shell 30 and the outer wall 23 of the inner shell 20 are opposite to each other. The outer shell 30 completely surrounds the inner shell 20 in the axial direction, but this is not an absolute requirement. For example, the inner shell 20 can also protrude, but this will lead to a decrease in stability, especially in the horizontal direction.

[0076] In this embodiment, the outer shell and the inner shell are cylindrical, which has been proven to be beneficial for uniform weight loading and vibration reduction. In this way, the outer shell 20 and the inner shell 30 as well as the spiral spring 50 can be arranged coaxially about the center line 51, which is very beneficial for uniform weight distribution and uniform load distribution.

[0077] The outer shell 30 and the inner shell 20 are mechanically rigidly connected to each other in the horizontal direction.

[0078] In order to achieve the movement required for vibration isolation, the inner housing 20 is movably held in the outer housing 30 in the vertical direction. In other words, the inner housing 20 with the coil spring 50 is movable relative to the outer housing 30 in the axial direction or the vertical direction.

[0079] In this embodiment, the horizontal rigid connection of the inner shell 20 is implemented by two leaf spring groups 34 as vertically acting spring elements parallel to the actuator 40. The leaf spring group 34 is arranged in the working space 32 of the vibration isolator 10 and connects the inner shell 20 to the outer shell 30.

[0080] In this embodiment, the vibration isolator 10 includes two leaf spring groups 34, which are spaced apart from each other in the axial direction and arranged on the corresponding end sides of the inner shell 20 and the outer shell 30, so as to provide the greatest possible stability in the horizontal direction. In this way, the tilt of the inner shell 20 relative to the outer shell 30 can be offset, thereby ensuring a rigid connection in the horizontal direction.

[0081] The leaf spring group 34 comprises a plurality of leaf springs. In addition to leaf springs, other spring elements, such as disc springs, are also conceivable.

[0082] The leaf spring group 34 is arranged to facilitate replacement. For this reason, a clamping ring 35 is provided on the end side, which can be used to fix the leaf spring group 34 and detachably connect it to the housing 30, thereby retaining the leaf spring group 34.

[0083] Replacing the spring element allows the natural frequency of the vibration isolator 10 to be adjusted in a simple manner, so that it can be adapted to different load situations. In particular, natural frequencies of more than 5 Hz can be achieved in order to shorten the stabilization time.

[0084] The coil spring 50 is mechanically rigidly coupled to the inner housing 20 in the horizontal direction, thereby isolating vibrations in the vertical direction. The inner housing 20 is configured to receive and retain the coil spring 50 using a corresponding mechanism, in this case, the lower spring seat 24, allowing the coil spring 50 to be fixed in place in the horizontal and vertical directions. The spring seat 24 can be moved in the axial direction by an adjustment member 52 to adjust the height.

[0085] According to the invention, an actuator acting in vertical direction is provided, which is arranged in the working space of the vibration isolator and is generally designated with reference numerals 40, 40a. The actuator 40, 40a is designed as a linear motor with a rectilinear motion path and is able to apply a force to the vibration isolator 10 particularly uniformly.

[0086] In this embodiment, the actuator 40, 40a is configured as a magnetic actuator, including coils 41, 41a and magnets 42, 42a, each forming a magnet-coil pair. The coil 41 and the magnet 42 are arranged in the working space 32 between the inner shell 20 and the outer shell 30, forming a magnet-coil pair. In the working space 32, a groove is formed on the inner wall of the outer shell 30 and / or a groove is formed on the outer wall of the inner shell 20 for accommodating the magnet 42 or the coil 41. In this embodiment, the coil is pressed or bonded to the outer wall of the inner shell 20. Advantageously, the inner shell 20 is made of an iron-containing material, preferably steel. The magnet 42 is embedded and bonded into a precisely matched groove on the inner wall of the outer shell 30.

[0087] In this way, the actuator 40, 40a can achieve additional vibration isolation in the vertical direction in parallel with the coil spring 50. The actuator 40, 40a represents the active element of the vibration isolator 10.

[0088] In the illustrated embodiment, a total of three magnet coil pairs are provided, which completely surround the helical spring 50 and extend substantially along the length of the helical spring 50 in the axial direction. This arrangement facilitates a compact design of the vibration isolator 10 while improving stability.

[0089] In the embodiment shown, the magnet coil pair is constructed in an annular shape. In this way, the helical spring 50 can be completely surrounded. In this way, the vibration isolator 10 can be particularly evenly applied by the actuator 40, 40a. In particular, this can prevent the actuator 40, 40a from causing the inner shell 20 to tilt due to uneven one-sided force.

[0090] In the embodiment shown, the windings of the coil 41 of the actuator 40, 40a extend around the outer wall of the inner housing 20. An associated magnet 42, in this embodiment a permanent magnet, is assigned to the outer housing 30 and is arranged on the inner wall relatively close to the coil 41.

[0091] Therefore, the magnet 42 and the associated coil 41 are opposed to each other with a gap therebetween.

[0092] Since the inner shell 20 and the outer shell 30 are rigidly connected in the horizontal direction, the gap is correspondingly particularly narrow. In the present embodiment, the width of the gap is less than 5 mm, preferably less than 1 mm, and particularly preferably less than 0.5 mm. In this way, the working space 32 can be made correspondingly smaller, so that the vibration isolator 10 as a whole remains compact, and a relatively high force can be generated. It is also possible to imagine that the magnet 42 and the coil 41 are arranged in the opposite manner.

[0093] In the embodiment shown, the vibration isolator 10 comprises three parallel actuators 40, 40a, in this case magnetic actuators or magnet coil pairs, juxtaposed to one another in the axial direction. In general, embodiments comprising more than one actuator 40, 40a, for example two or four or five or more actuators 40, 40a, in particular magnetic actuators, arranged juxtaposed to one another can be envisaged.

[0094] This allows a greater force to be generated in a compact working space 32. In this case, current flows in opposite directions through the magnet coil pairs juxtaposed to each other. In the arrangement of three magnet coil pairs, two axially spaced magnetic fields can be formed.

[0095] In order to be able to apply force evenly over a length range with an odd number of magnet coil pairs (for example, three or five magnet coil pairs), the middle magnet coil pair (marked with reference numeral 40a in this example) is larger than the outer magnet coil pairs or actuator 40 so that an equal or higher force can be applied at the same current. For this purpose, the coil 41a in the middle magnet coil pair 40a having coil 41a and magnet 42a has twice the number of coil windings compared to the two outer magnet coil pairs. Different wire cross sections, especially larger wire cross sections, or a combination of variable wire cross sections and variable winding numbers can also be selected. The outer magnet coil pairs are constructed to have the same performance parameters.

[0096] In the axial direction, adjacent magnet coil pairs are separated by a certain distance, and in this embodiment, the distance is 1 mm to 5 mm. In order to shorten the distance, in this embodiment, a shielding intermediate piece 43 is provided between adjacent magnet coil pairs.

[0097] In the illustrated embodiment, the isolator 10 further includes an elongated insert 25 for receiving the load. The insert 25 extends mostly into the coil spring 50. The insert 25 is fixedly connected to the inner shell 20 at the upper end.

[0098] The insert 25 includes an upper receiving portion for receiving a coil spring, in this case, an upper spring seat 24. In another embodiment, the insert 25 can also constitute a part of the inner shell 20 together with the upper spring seat 24.

[0099] In this case, the insert 25 is formed with an upwardly open cavity in the region protruding into the coil spring 50 for accommodating a load receiving portion 53. The load receiving portion 53 is arranged coaxially with the insert 25 and the coil spring 50 and is fixedly connected in the axial direction and radial direction in the bottom region of the insert 25 in the lower region of the cavity. The load receiving portion 53 is thus held on the bottom of the insert. In the upper region or upper end side of the insert 25, the load receiving portion 53 is freely arranged in the cavity in the horizontal direction so that it can move in the radial direction.

[0100] In this embodiment, the load receiving portion 53 is designed as a bent rod, the upper end of which can be connected to the load to be isolated. For this purpose, an additional receiving portion 54 is provided in this embodiment. The load to be isolated is not shown in this figure. Therefore, the load receiving portion 53 can absorb the forces acting on the load to be isolated in the horizontal direction.

[0101] Figure 2 The isolator 10 is shown in an oblique view. The lateral grooves 36 allow for height adjustment of the assembled isolator 10. The isolator 10 has a total height of about 150 mm and a diameter of about 130 mm, which makes the structure very compact. The elongation of the helical spring in the axial direction is about 90 mm. A total of approximately three magnet coil pairs are distributed over this distance, wherein the length of the middle magnet coil pair in the axial direction is approximately twice the length of the outer magnet coil pairs. With the above dimensions, a stroke of approximately 1.5 mm or more can be achieved.

[0102] Figure 4 The cross-sectional oblique view shows Figure 2 The vibration isolator 10 is shown.

[0103] Figure 5 The side walls of the inner shell 20 and the outer shell 30 of the vibration isolator 10 are shown in cross-section.

[0104] Figure 6 The magnetic field generated during operation of this side wall region of the vibration isolator 10 is shown. It can be clearly seen that two magnetic fields 44 are formed, which are axially spaced apart from each other. In the cross-sectional view, the course of the magnetic field lines is schematically marked with the reference numeral 45.

[0105] In summary, the present invention provides a method for isolating a load to be supported, such as an electron scanning microscope 5, a lithography instrument or lithography system, an optical inspection instrument, a wafer or substrate processing system or device, or any other device or system with particularly high vibration isolation requirements.

[0106] The present invention also relates to an apparatus, such as a lithography apparatus or photolithography device, an optical inspection apparatus, a wafer or substrate processing apparatus or device, using at least one vibration isolator 10 as described above.

Claims

1. A vibration isolator, comprising: an inner housing having a cavity for receiving and retaining the coil spring, The coil spring is arranged in the cavity of the inner shell and acts in a vertical direction; an outer shell at least partially surrounding the inner shell; as well as The actuator acts in a vertical direction and is arranged between the inner shell and the outer shell.

2. Vibration isolator according to the preceding claim, characterized in that At least one spring element, preferably at least one leaf spring, is arranged between the outer shell and the inner shell, so that the inner shell can move axially relative to the outer shell.

3. A vibration isolator according to any one of the preceding claims, characterized in that At least two leaf springs are provided which are arranged spaced apart from one another in the axial direction and are preferably designed as a leaf spring package.

4. A vibration isolator according to any one of the preceding claims, characterized in that The actuator is configured as a magnetic actuator, and includes at least one coil and a magnet, wherein the coil and the magnet configure a magnet-coil pair.

5. A vibration isolator according to any one of the preceding claims, characterized in that A recess is provided in the working space to accommodate the coil and / or magnet of the magnetic actuator.

6. A vibration isolator according to any one of the preceding claims, characterized in that The at least one magnet coil pair at least partially surrounds the helical spring.

7. A vibration isolator according to any one of the preceding claims, characterized in that The at least one magnet coil pair is annular in shape and completely surrounds the helical spring at least in sections.

8. A vibration isolator according to any one of the preceding claims, characterized in that A plurality of actuators are provided, in particular magnet coil pairs, preferably two magnet coil pairs, particularly preferably three or more magnet coil pairs, arranged juxtaposed to each other in the axial direction, wherein preferably, the winding directions of adjacent coils and the magnetization directions of the magnets between adjacent magnet coil pairs are alternated.

9. Vibration isolator according to the preceding claim, characterized in that The distance between two adjacent magnet coil pairs is 1 mm to 5 mm.

10. A vibration isolator according to any one of the preceding claims, characterized in that The coil of the at least one magnet-coil pair is arranged on the outer wall of the inner shell and / or the associated magnet is arranged on the inner wall of the outer shell.

11. A vibration isolator according to any one of the preceding claims, characterized in that A gap is provided between the magnet and the coil in one magnet-coil pair, wherein the width of the gap is smaller than 5 mm, preferably smaller than 1 mm, particularly preferably smaller than 0.5 mm.

12. The vibration isolator according to any one of the preceding claims, further comprising: It projects at least partially into an insert of the coil spring, which insert has a cavity which is preferably open upward.

13. Vibration isolator according to the preceding claim, characterized in that The insert is connected to a load receiver which is fixedly connected to the insert in the axial direction and in the radial direction.

14. Vibration isolator according to the preceding claim, characterized in that The load receiver projects at least partially into the cavity of the insert and / or the load receiver projects at least partially into the helical spring.

15. A vibration isolator according to any one of the two preceding claims, characterised in that The load receiving part is connected at its lower end to the bottom of the insert and / or at its upper end to the load to be isolated or the load receiving part.

16. A vibration isolator according to any one of the three preceding claims, characterised in that The load receiver is designed as a bent lever or as an articulated pendulum.

17. A vibration isolator according to any one of the preceding claims, characterised in that The helical spring is mechanically rigidly connected to the inner housing in a horizontal direction.

18. A method for isolating a load to be supported, comprising a vibration isolator according to any one of the preceding claims.

19. An apparatus, in particular a lithography apparatus or photolithography device, an optical inspection apparatus, a wafer or substrate processing system or device, comprising at least one vibration isolator according to any one of the preceding claims.

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