NL2017646B1 - Machine support frame and method for mounting a vibration sensitive machine - Google Patents

Abstract

A machine support frame (MSF) for supporting a vibration sensitive machine (10) and method for mounting such machine (10) in a potential earthquake environment. The machine support frame (MSF) comprises a high stiffness support block (20). A top surface of the support block (20) comprises a plurality of connection interfaces (21). Each connection interface (21) is configured to provide a fixed connection (S) with a respective support foot (11) of the machine (10). Each connection interface (21) is connected via a friction bearing (F) with the support block (20).

Description

Title: MACHINE SUPPORT FRAME AND METHOD FOR

MOUNTING A VIBRATION SENSITIVE MACHINE

TECHNICAL FIELD AND BACKGROUND

The present disclosure relates to a machine support frame for supporting a vibration sensitive machine and a method for mounting such machines in particular in a locality where earthquakes may occur.

For optimal functioning, a vibration sensitive machine such as an optical or lithographic apparatus can be mounted on top of a machine support frame (MSF). The MSF typically comprises a rigid or high stiffness support block, e.g. a solid slab of (reinforced) concrete. The support block may be fixed on top of the building floor to act a rigid base or pedestal for the machine. In this way it is not necessary to adapt the stiffness of the entire building floor.

While the high rigidity of the MSF may normally improve the functionality of the vibration sensitive machine, the inventors found that this same quality may be undesired during extreme vibrations of the building floor. In particular, the inventors found that an earthquake event may be very destructive to an MSF mounted machine, even though the building itself can remain relatively undamaged.

There is a need for an improved MSF and method of mounting vibration sensitive machines alleviating potential damage that may be caused by an earthquake event.

SUMMARY

According to one aspect, the present disclosure provides a machine support frame for supporting a vibration sensitive machine. The machine support frame comprises a high stiffness support block. A top surface of the support block comprises a plurality of connection interfaces. Each connection interface is configured to provide a fixed connection with a respective support foot of the machine. Advantageously, each connection interface is connected via a friction bearing with the support block.

On the one hand, the friction bearings can provide a static (stiff) connection between the support block and the machine under normal circumstances. In this way, the presence of the friction bearings may have minimal or no influence on the functionality of the vibration sensitive machine under normal circumstances. On the other hand, the friction bearings can provide a sliding connection between the machine and the support block in case of an earthquake. Sliding of the machine with respect to the support block in case of an earthquake may prevent excessive shaking of the machine which could otherwise cause significant damage.

By having the machine stiffly connected to a heavy and stiff support block undesired vibrations of the machine may be minimized during normal circumstances. Accordingly, it may be desired to have the connection interfaces provide a relatively high horizontal and/or vertical stiffness, e.g. more than 107 Newton per meter (force between the machine and support block resisted by the connection interface), preferably more than 108 Newton per meter, most preferably more than 109 Newton per meter.

The support block may be generally is formed by a slab or plate of material. The support block is generally distinct from the building floor, e.g. laid on top of the building floor and/or a support structure of the building. In some cases, the support block may be arranged on a support structure at a distance above a building floor. Typically, the support block is fixedly connected to the building floor via the support structure at a distance above a building floor. For example, the support block is glued and/or screwed on the support structure. In effect, the support block provides a desired stiffness without having to redesign the building.

To resist bending, the support block may have has a certain thickness, e.g. more than ten centimeter, preferably more than fifteen centimeter, e.g. twenty centimeter. To support the machine, the support block has a corresponding surface area over which area three, four, or more connection interfaces can be provided. For example, the support block has a length and/or width of more than one meter, or more than two meter, e.g. five by ten meters.

By providing a stiff support block, undesired vibrations in the support block can be minimized at operating frequencies well below any resonance frequencies of the block. For example, the stiffness of the block may be characterized by a modulus of elasticity (E), e.g. more than one Giga-Pascal, preferably more than ten Giga-Pascal, e.g. between twenty and fifty Giga-Pascal. A support block made from concrete material, e.g. reinforced concrete, may have desired stiffness qualities and can be relatively easy to produce.

By providing a heavy support block, its mass may be relatively resistant to being accelerated by external forces. For example, the support block may have a mass of more than thousand kilograms, or even more than ten thousand kilograms. Similarly, the machine can be heavy, e.g. having a mass of more than thousand kilograms, or even more than ten thousand kilograms, e.g. twenty ton.

The connection interfaces may comprise a foot-plate for connection to the respective machine foot. For example the foot-plate comprises holes, e.g. screw holes to fix a respective machine foot to the footplate. Also other fixation means can be provided, e.g. clamps to fixate the machine feet to the connection interfaces. The friction bearing is generally between the footplate and the support block.

Friction bearings are generally formed by two contacting surfaces having a certain amount of friction there between. The contacting surfaces are otherwise free to move at least along a direction of the surfaces, i.e. the surfaces are not statically fixed together by fixation means such as glue, screws or bolts. For example, a respective friction bearing is formed by a surface of the connection interface contacting a surface of the support block, typically a lower surface of the connection interface resting on top of an upper surface of the support block. Since the strongest accelerations of an earthquake are typically in the horizontal plane, the friction bearings may similarly be configured to provide a horizontal sliding connection between the connection interface and the support block i.e. parallel to the top surface of the support block.

By adapting the friction bearings to provide a particular coefficient of static friction (ps), the acceleration at which the machine starts sliding can be predetermined. Without being bound by theory, the following insight is provided. To horizontally accelerate a machine of mass “M” at rate of acceleration “a” requires a static friction force “Ff > M· a”. The maximum static friction force “Ff’ is determined by the coefficient of static friction “ps” between the connecting interfaces and the normal force “Fn” on the connecting interfaces as “Ff = ps · Fn”. The normal force “Fn” exerted by the machine of mass “M” is determined by “Fn = M· g” (g~9.8 m/s2). Combining these formulas leads to “ps · M· g > M· a” which can be written as ”a < ps · g”. Accordingly, the connection interfaces may start sliding over the support block only when a horizontal acceleration “a > ps' g”. It will be appreciated that the mass “M” cancels from the equation and the intended frictional characteristics of the MSF can be more or less independent of the machine.

For example, when the coefficient of static friction ps=0.1, the connection interfaces provide a static connection up to an acceleration of 0.98 m/s2. During normal (non-earthquake) circumstances, the acceleration is much lower (e.g. « O.OOlg) and the connection interfaces stiffly connect the machine 10 to the support block. At higher acceleration, typically occurring during earthquake, the machine connected to the connection interfaces is allowed to start sliding with respect to the support block for preventing internal damage to the machine. Depending on the situation, it is generally found advantageous to provide a coefficient of static friction ps preferably somewhere in a range between 10-4 and 10_1.

Even though the connection interfaces are allowed to slide, in some cases, it is desired to provide some form of fixation so the machine (fixed to the connection interfaces) does not bounce up and down on the support block during earthquake. By providing vertical movement limiters, vertical movement of the connection interface may be minimized, also during earth-quake conditions. Of course, the vertical movement limiters should still allow horizontal sliding of the connection interface with respect to the support block during earth-quake conditions. For example, the vertical movement limiter comprises a vertical connecting element between the connection interface and the support block wherein a tension of the vertical connecting element is mainly or exclusively directed along a vertical direction transverse to a direction of the friction bearing. By providing the vertical movement limiter with a resilient element, this may act against vertical movement of the connection interface with respect to the support block while still allowing some horizontal movement. For example, the resilient element can have a relatively high stiffness to resist movement under normal circumstances, e.g. between 107 and 1010 Newton per meter. The resilient element can also be preloaded, e.g. to set an amount of pressure and/or friction between the connection interface and the support block.

Alternatively, or in addition to the vertical limiters, it may also be desired to limit a maximum horizontal range of the sliding connection interfaces, e.g. so the machine does not completely slide off the support block. It is typically found sufficient if the connection interfaces are limited to a horizontal range of movement less than ten centimeters, preferably less than six centimeters, e.g. a maximum horizontal deflection of plus-minus three centimeters. For example, the range of motion may be limited by abutment surfaces of the support block. The abutment surfaces may protrude from the support block or may be formed e.g. by the sidewalls of a recessed (blind) hole in which the connection interface can be located. By providing a rather limited range of motion, the machine may be easily brought back to its original position after the earthquake. Optionally, displacement means may be provide to move the machine back to its position after an earthquake event.

By providing dampers between the abutment surfaces and the surface, the horizontal movement of the connection interface during earthquake conditions can be dissipated and/or more gradually decelerated instead of hitting a hard wall. Preferably, the dampers comprise a progressive damping structure, i.e. providing more damping, the further the connection interface deviates from its normal position. For example, the damper comprise two or more different material layers in a sequence between the connection interface and an abutment surface of the support block. Each next material layer in the sequence may be configured to provide progressively higher stiffness and/or surface area. For example, a respective damper may be arranged as a ring around a circumference of a respective connection interface, e.g. comprising damper material disposed along side walls of a respective blind hole in the support block. By alternatively or additionally providing a viscous damping structure, the horizontal motion of the connection interface can be effectively dissipated during earthquake conditions. Preferably the dampers provide minimal or no resonance when the connection interface is in loose state, in order to limit the horizontal movement range of the machine in loose state. For example, the energy dissipation in the dampers is sufficient to prevent amplification of movement at their resonance frequency, e.g. critically damped.

Some aspects of the present disclosure may also be embodied as a combined system comprising a vibration sensitive machine mounted to the machine support frame as described herein. For example, the vibration sensitive machine is an optical device, e.g. lithographic machine. Other or further aspects may relate to methods for mounting a vibration sensitive machine in a potential earthquake environment. The method comprises statically or fixedly connecting the machine to a plurality of connection interfaces. The connection interfaces are distributed over the surface of high stiffness a support block forming a machine support frame. Each connection interface is connected via a friction bearing with the support block.

BRIEF DESCRIPTION OF DRAWINGS

These and other features, aspects, and advantages of the apparatus, systems and methods of the present disclosure will become better understood from the following description, appended claims, and accompanying drawing wherein: FIG 1 schematically illustrates a cross-section view of an embodiment of system comprising a vibration sensitive machine mounted to a machine support frame; FIG 2 schematically illustrates a close-up view of an embodiment of a connection interface of the machine support frame; FIG 3 schematically illustrates a close-up view similar to FIG 2 but wherein the connection interface is deflected during an earthquake.; FIG 4A schematically illustrates three different cross-section views of an embodiment of a system with a machine on top of a machine support frame; FIG 4B schematically illustrates the same views as FIG 4A but of another embodiment comprising a coupling between the interfaces; FIG 5A shows a photograph of a typical support structure for carrying the machine support frame (MSF); FIG 5B shows a photograph of the machine support frame (without the machine).

DESCRIPTION OF EMBODIMENTS in an idealized or overly formal sense unless expressly so defined herein. In some instances, detailed descriptions of well-known devices and methods may be omitted so as not to obscure the description of the present systems and methods. Terminology used for describing particular embodiments is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "and/or" includes any and all combinations of one or more of the associated listed items. It will be understood that the terms "comprises" and/or "comprising" specify the presence of stated features but do not preclude the presence or addition of one or more other features. It will be further understood that when a particular step of a method is referred to as subsequent to another step, it can directly follow said other step or one or more intermediate steps may be carried out before carrying out the particular step, unless specified otherwise. Likewise it will be understood that when a connection between structures or components is described, this connection may be established directly or through intermediate structures or components unless specified otherwise. A pedestal or machine support frame (MSF) normally provides a stiff interface between a machine and floor. It will be appreciated that the present disclosure has a distinct advantage in that the solution it is applied to the machine-pedestal interface and not to the whole pedestal, floor or building. Some aspects of the present disclosure may provide a pedestal with a well-defined coupling to the machine (anchoring) e.g. having one or more of the following functions: 1) In normal conditions: stiff in horizontal and vertical directions. 2) During an earthquake: horizontal acceleration exceeds a specified threshold enabling the machine to slide e.g. up to a few centimeters, thus limiting acceleration forces on the machine. 3) Preventing the machine from sliding too much or breaking loose in any condition.

In some embodiments, the quake-safe machine interface (QSMI) comprises is a footplate-unit or connection interface incorporated in a machine pedestal. A machine foot can be coupled (bolted, secured) to such a unit. Generally, a pedestal will house three or four QSMI units to couple the three or four main machine feet to the pedestal. The connection interface 21 may e.g. comprise some of the following parts: 1) Foot-Plate for machine foot. The machine foot can be secured to this plate with bolts or otherwise. The footplate rests on the bottom of unit. 2) Friction Bearing. The interface between the foot-plate and the unit. When a large horizontal force works on the foot-plate it can slide and works as a friction damper, under normal conditions the foot-plate is stiff and fixed due to friction. 3) Vertical Movement Limiter (VML). Large acceleration in upward direction during an earthquake could lead to forces acting on the machine in upward direction. The VML can prevent that the footplate is pulled out of the unit by these forces. The VML should still allow horizontal movement of the foot-plate. 4) Progressive Stiffness Damper (PSD). The PSD may have a function to limit the horizontal movement to a few centimeter and to provide additional damping. For low intensity earthquakes, the machine can move freely, inducing none or a small indention of the damper, resulting in a high reduction of acceleration. For higher intensity earthquakes the indention of the damper can become larger and the damper’s reaction force therefore increases progressively. This may limit the horizontal movement while still alleviating acceleration forces compared to a non-sliding machine. 5) In some variations, the QSMI units may all be coupled to ensure that all machine feet move as one. Alternatively or in addition to progressive stiffness damping, also other or further damping options may be envisaged such as eddy-current damping, viscous damping, or inertial damping.

The invention is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The description of the exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the drawings, the absolute and relative sizes of systems, components, layers, and regions may be exaggerated for clarity. Embodiments may be described with reference to schematic and/or cross-section illustrations of possibly idealized embodiments and intermediate structures of the invention. In the description and drawings, like numbers refer to like elements throughout. Relative terms as well as derivatives thereof should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description and do not require that the system be constructed or operated in a particular orientation unless stated otherwise. FIG 1 schematically illustrates a cross-section view of an embodiment of system 100 comprising a vibration sensitive machine 10 mounted to a machine support frame MSF.

As described herein, the machine support frame MSF is configured to support a vibration sensitive machine 10. In one embodiment, the MSF comprises a high stiffness support block 20. In another or further embodiment, a top surface of the support block 20 comprises a plurality of connection interfaces 21. Preferably, each connection interface 21 is configured to provide a fixed connection S with a respective support foot 11 of the machine 10. Furthermore, each connection interface 21 is connected via a friction bearing F with the support block 20.

Some aspects of the present disclosure may also provide methods for mounting a vibration sensitive machine 10 in a potential earthquake environment. Such methods may comprise (statically) connecting the machine 10 to a plurality of connection interfaces 21 which are distributed over the surface of high stiffness a support block 20 forming a machine support frame MSF. As described herein, the connection interfaces 21 are preferably connected via a friction bearing F with the support block 20. These or other methods may thus provide a system 100 comprising a vibration sensitive machine 10 mounted to the machine support frame MSF as described herein.

In one embodiment, the friction bearings F are adapted to provide a static connection between the support block 20 and the machine 10 under normal circumstances, i.e. wherein the support block 20 and/or surrounding support structure 31,32 experiences minimal or no acceleration, e.g. below 0.1 m/s2 . For example, such acceleration may correspond to a peak ground acceleration PGA that is perceptible as light shaking O.Olg by people and typically does not cause significant damage.

In another or further embodiment, the friction bearings F are configured to provide a sliding connection between the machine 10 and the support block 20 in case of an earthquake, i.e. wherein the support block 20 and/or surrounding support structure 31,32 experiences significant acceleration, e.g. above 0.1 m/s2. This allows the machine to slide with respect to the support block in case of an earthquake and may prevent excessive shaking of the machine 10 which would otherwise cause significant damage to components inside the machine 10. Accordingly, it may be preferred that the friction bearings F are configured to provide a coefficient of static friction ps at a predetermined value in a range between 10-4 and 10.-1.

The concept of a vibration sensitive machine refers to a machine whose functional operational can be negatively impacted by small vibrations (e.g. with a vibrational amplitude between one and hundred micron) and which may occur in a building under normal circumstances, e.g. caused by vibration sources in the building itself or adjacent the building (traffic). For example, the vibration sensitive machine 10 is an optical device, e.g. lithographic machine, wherein high precision can be achieved only if any undesired vibrations are sufficiently dampened. In some embodiments, vibrations may be actively dampened, e.g. using an active damping system on the MSF, on the machine, on the building floor, or any where in between, or combinations thereof.

In some embodiments, the machine 10 is relatively heavy, e.g. having a mass of more than thousand kilograms, or even more than ten thousand kilograms, e.g. twenty ton. Preferably, the machine 10 is stiffly connected to the support block 20 via the connection interface 21 during normal circumstances, i.e. as long as a relative acceleration between the machine 10 and support block 20 remains below a threshold where the friction bearings F bearings start sliding. For example, the connection interfaces 21 provide a horizontal and/or vertical stiffness of more than 107 Newton per meter, preferably more than 108 Newton per meter, most preferably more than 109 Newton per meter. FIG 2 schematically illustrates a close-up view of an embodiment of a connection interface 21 of the machine support frame MSF. In this view, the connection interface 21 is in its normal position.

Typically, the connection interfaces 21 each comprises a foot-plate 21a for connection to the respective machine foot 11. As shown, the friction bearing F is disposed between the foot-plate 21a and friction surface 20f of the support block 20. In the embodiment shown, the foot-plate 21a comprises holes, e.g. screw holes 21s to fix a respective machine foot 11 to the foot-plate 21a.

In some embodiments, a respective friction bearing F is formed by a frictional surface 2 If of the connection interface 21 contacting a frictional surface 20f of the support block 20, e.g. a lower surface 21f of the connection interface 21 resting on top of an upper surface 20f of the support block 20. In another or further embodiment, the friction bearings F are configured to provide a horizontal sliding connection between the connection interface 21 and the support block 20 i.e. parallel to the top surface. A frictional coefficient may e.g. be determined by a surface roughness and/or material of the frictional surfaces 20f and 2 If.

In a preferred embodiment, the machine support frame MSF comprises vertical movement limiters V for preventing vertical movement of the connection interface 21 also during earth-quake conditions. The vertical movement limiters V should still allow horizontal sliding of the connection interface 21 with respect to the support block 20 during earth-quake conditions. In the embodiment shown, a respective vertical movement limiter V comprises a vertical connecting element 23a between the connection interface 21 and the support block 20 wherein a tension of the vertical connecting element 23 is mainly or exclusively directed along a vertical direction transverse, e.g. perpendicular, to a direction of the friction bearing F. For example, the vertical connecting element 23a comprises a threaded element through a hole 21v of the connection interface 21, secured by a nut.

In another or further embodiment, the vertical movement limiter V comprises a resilient element 23b, e.g. spring, acting against vertical movement of the connection interface 21 with respect to the support block 20. For example, the resilient element 23b has a stiffness between 106 and 1010 Newton per meter. In some cases, the resilient element 23b is preloaded to set an amount of pressure and/or friction between the connection interface 21 and the support block 20. For example, the resilient element 23b is preloaded by a nut 23c on a thread of the vertical connecting element 23a, wherein the resilient element 23b is arranged between the nut 23c and the support block 20. FIG 3 schematically illustrates a close-up view similar to FIG 2 but wherein the connection interface 21 is deflected during an earthquake by a horizontal distance ΔΧ.

In a preferred embodiment, the machine support frame MSF comprises horizontal range limiters to limit a maximum horizontal range of the sliding connection interfaces 21 with respect to the support block 20 during earthquake conditions. For example, the connection interfaces 21 are limited to a horizontal range of movement, e.g. between one and ten centimeters, preferably less than six centimeters, e.g. a maximum horizontal deflection of plus-minus three centimeters. In the embodiment shown, the connection interface 21 comprises a structure that is contained by a respective recessed blind hole into a top surface 20t of the support block 20.

In another or further embodiment, the machine support frame MSF comprises dampers 22 for limiting and/or dissipating horizontal movement of the connection interface 21 during earthquake conditions. Preferably, the dampers 22 comprise a progressive damping structure. For example, the dampers comprises two or more different material layers 22a,22b,22c in a sequence between an abutment surface 21h of the connection interface 21 and a wall of the support block 20.

In the embodiment shown, each next material layer in the sequence is configured to provide progressively higher stiffness the more a horizontal position of the connection interface 21 deviates from a central position. Preferably, a respective damper 22 is disposed as a ring around a circumference of a respective connection interface 21. For example, the damper 22 comprises damper material disposed along side walls of a respective blind hole in the support block 20.

In the embodiment shown, a respective damper 22 comprises a concentric rubber rings 22a,22b,22c with increasing stiffness and/or increasing surface area of an outer ring 22c with respect to an inner ring 22a. In another or further embodiment, the dampers 22 comprise a viscous damping structure for dissipating horizontal motion of the connection interface 21 during earthquake conditions. For example a horizontal resonance frequency (in loose state during earthquake) is non linear e.g. from 0.1 Hz - 10 Hz. FIG 4A schematically illustrates three different cross-section views of an embodiment of a system 100 with a machine 10 on top of a machine support frame MSF. The left side shows the front 20f of the support block and the front 31f of the support structure. The machine 10 is mounted via the connection interfaces 21 on top of the support block. The top right side shows a top surface 20t of the support block 20a with the connection interfaces 21 from the top. While the interfaces 21 are depicted as rectangular, they can be any shape e.g. round so they are not affected by any particular direction of an earthquake. The bottom right side shows the side view 20s and 31s of the support block and support structure, respectively. FIG 4B is similar to the embodiment of FIG 4A, except the system 100 comprising a coupling 24 between the interfaces 21. Such coupling e.g. rigid connection between the connection interfaces, may ensure that all machine feet move as one. In the embodiment shown, the coupling 24 is provided through the support block 20. In some embodiments, the coupling may be arranged in trenches of the support block 20 between the positions of the connection interface 21. FIG 5A shows a photograph of an example support structure 31,32 for carrying the machine support frame (MSF). FIG 5B shows a photograph of the support block 20 of the machine support frame (MSF) mounted on the support structure 31,32 (without the machine).

Preferably, the support block 20 is relatively stiff, e.g. has a modulus of elasticity E of more than one Giga-Pascal (1 GPa=109 N/m2), preferably more than ten Giga-Pascal, e.g. between twenty and fifty Giga-Pascal. In one embodiment, the support block 20 is formed by a slab or plate of material with a thickness of more than ten centimeter (cm), preferably more than fifteen centimeter, e.g. between twenty and fifty centimeter. For example, the support block 20 has a length and/or width of more than one meter, or more than two meter, e.g. five by ten meters. In a preferred embodiment, the support block 20 comprises concrete material, e.g. reinforced concrete. It will be appreciated that the support block 20 is distinct from a building floor, e.g. laid on top of the building floor.

In the embodiment shown, the support block 20 is arranged on an (open) support structure 31,32. For example, the support block 20 is fixedly connected to the building floor 34 via the support structure 31,32 at a distance above a building floor 34. In some embodiments, the support block 20 is glued and/or screwed on the support structure 31,32. In other embodiments, the support block 20 is simply immobile due to its sheer weight.

In one embodiment, the open support structure 31,32 comprises beams 32 forming a fab floor that is heightened with respect to a deeper building floor 34. In another or further embodiment, the support structure 31,32 comprises concrete beams 32 forming the heightened fab floor. For example, the support structure 31,32 comprises steel beams 31 between the support block 20 and the building floor 31. In the embodiment shown, the steel beams 31 are laid across the concrete beams 32 forming the heightened fab floor.

In some embodiments, as show, a flat walking floor is formed extending adjacent the support block 20 by heightened floor sections 33 on top of the fab floor. For example, the walking floor is approximately at a same height as a top surface of the support block 20. In one embodiment (not shown), a further (vibration insensitive) machine is arranged on the walking floor next to the vibration sensitive machine. For example, the machines cooperate to form parts of a combined system.

For the purpose of clarity and a concise description, features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described. For example, while embodiments were shown for specific forms of the friction bearings, also alternative ways may be envisaged by those skilled in the art having the benefit of the present disclosure for achieving a similar function and result. E.g. mechanical components may be combined or split up into one or more alternative components. The various elements of the embodiments as discussed and shown offer certain advantages, such as protecting vibration sensitive machines against earthquakes while at the same time providing a stiff support frame. Of course, it is to be appreciated that any one of the above embodiments or processes may be combined with one or more other embodiments or processes to provide even further improvements in finding and matching designs and advantages. It is appreciated that this disclosure offers particular advantages to optical systems working at small length scales, and in general can be applied for any machine support frame.

Finally, the above-discussion is intended to be merely illustrative of the present systems and/or methods and should not be construed as limiting the appended claims to any particular embodiment or group of embodiments. In interpreting the appended claims, it should be understood that the word "comprising" does not exclude the presence of other elements or acts than those listed in a given claim; the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements; any reference signs in the claims do not limit their scope;; any of the disclosed devices or portions thereof may be combined together or separated into further portions unless specifically stated otherwise. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage. In particular, all working combinations of the claims are considered inherently disclosed.

Claims (15)

A machine support frame (MSF) for supporting a vibration sensitive machine (10), the machine support frame (MSF) comprising a high-rigidity support block (20) wherein an upper surface of the support block (20) has a plurality of connection interfaces (21 ), wherein each connection interface (21) is configured to provide a fixed connection (S) with a respective support foot (11) of the machine (10), characterized in that each connection interface (21) is connected via a friction bearing (F ) with the support block (20). The machine support frame (MSF) according to claim 1, wherein the friction bearings (F) are adapted to provide a static connection between the support block (20) and the machine (10) under normal conditions where the support block (20) and / or the surrounding support structure (31, 32) experiences minimal or no acceleration, and provide a sliding connection between the machine (10) and the support block (20) in the event of an earthquake where the support block (20) and / or the surrounding support structure (31.32) experienced significant acceleration. The machine support frame (MSF) according to claim 1 or 2, wherein the friction bearings (F) are configured to provide a static coefficient of friction (ps) with a predetermined value in a range between 10_4 and 10_1. The machine support frame (MSF) according to any of the preceding claims, wherein the machine (10) is rigidly connected to the support block (20) via the connection interface (21) during normal conditions, wherein the connection interfaces (21) are horizontal and / or or provides vertical stiffness of more than 5 · 107 Newton per meter. The machine support frame (MSF) according to any of the preceding claims, wherein a respective friction bearing (F) is formed by a friction surface (21f) of the connection interface (21) in contact with a friction surface (20f) of the support block (20) wherein the friction bearings (F) are configured to provide a horizontal sliding connection between the connection interface (21) and the support block (20). The machine support frame (MSF) according to any one of the preceding claims, wherein the machine support frame (MSF) comprises vertical movement restrictors (V) to prevent vertical movement of the connection interface (21), also during earthquake conditions, wherein a respective vertical movement restriction (V) comprises a vertically connecting element (23a) between the connecting interface (21) and the support block (20) wherein a voltage of the vertically connecting element (23) is mainly or exclusively directed along a vertical direction, transversely of a direction of the friction bearing (F). The machine support frame (MSF) according to any one of the preceding claims, wherein the vertical movement limiter (V) comprises a resilient element (23b) that acts against vertical movement of the connection interface (21) relative to the support block (20), wherein the resilient member (23b) is biased to adjust an amount of pressure and / or friction between the connection interface (21) and the support block (20). The machine support frame (MSF) according to any one of the preceding claims, wherein the support block (20) has an elastic modulus (E) of more than ten Giga-Pascal. The machine support frame (MSF) according to any of the preceding claims, wherein the support block (20) is formed by a slab or plate of material with a thickness (Z) of more than ten centimeters, and a length and / or width of more than one meter. The machine support frame (MSF) according to any of the preceding claims, wherein the connection interface (21) comprises a foot plate (21a) for connection to the respective machine foot (11), the friction bearing (F) being placed between the foot plate (21a) ) and a surface (20f) of the support block (20), wherein the foot plate (21a) comprises holes and / or clamps for fixing a respective machine foot (11) to the foot plate (21a). The machine support frame (MSF) according to any of the preceding claims, comprising horizontal range limiters to limit a maximum horizontal range of the sliding connection interfaces (21) relative to the support block (20) during earthquake conditions, the connection interfaces (21) being limited to a horizontal range of movement between one and ten centimeters, the machine support frame (MSF) comprising dampers (22). The machine support frame (MSF) according to claim 11, wherein the dampers (22) comprise a progressive damping structure, wherein the dampers comprise two or more different material layers (22a, 22b, 22c) in a sequence between the connection interface (21) and a stop surface of the support block (20), wherein each subsequent layer of material in the sequence is configured to provide progressively higher stiffness the more a horizontal position of the connection interface (21) deviates from a central position. A system (100) comprising a vibration sensitive machine (10) mounted on the machine support frame (MSF) according to any one of the preceding claims. The system (100) of claim 13, wherein the support block (20) is arranged on an open support structure (31, 32) comprising support beams. A method for mounting a vibration sensitive machine (10) in a potential earthquake environment, the method comprising statically connecting the machine (10) to a plurality of connection interfaces (21) distributed over the surface of a high-rigidity support block (20) forming a machine support frame (MSF), characterized in that each connection interface (21) is connected via a friction bearing (F) to the support block (20).