WO2014090289A1 - Dispositif de positionnement, table à mouvements croisés et unité de levage - Google Patents

Dispositif de positionnement, table à mouvements croisés et unité de levage Download PDF

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Publication number
WO2014090289A1
WO2014090289A1 PCT/EP2012/075156 EP2012075156W WO2014090289A1 WO 2014090289 A1 WO2014090289 A1 WO 2014090289A1 EP 2012075156 W EP2012075156 W EP 2012075156W WO 2014090289 A1 WO2014090289 A1 WO 2014090289A1
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WO
WIPO (PCT)
Prior art keywords
unit
support unit
base unit
positioning device
lifting
Prior art date
Application number
PCT/EP2012/075156
Other languages
German (de)
English (en)
Inventor
Hans Eitzenberger
Jan Harnisch
Original Assignee
Eitzenberger Luftlagertechnik Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eitzenberger Luftlagertechnik Gmbh filed Critical Eitzenberger Luftlagertechnik Gmbh
Priority to PCT/EP2012/075156 priority Critical patent/WO2014090289A1/fr
Publication of WO2014090289A1 publication Critical patent/WO2014090289A1/fr

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/68—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for positioning, orientation or alignment
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K13/00—Apparatus or processes specially adapted for manufacturing or adjusting assemblages of electric components
    • H05K13/0015—Orientation; Alignment; Positioning

Definitions

  • a first aspect of the description relates to a positioning device having a base unit and a support unit, wherein the support unit is mounted on or on the base unit and horizontally movable relative to the base unit and is adapted to carry an object to be positioned.
  • the first aspect further relates to a cross table with such a positioning device.
  • a second aspect relates to a lifting unit comprising: a hollow cylinder; a piston mounted within the hollow cylinder which is retractable and retractable in a stroke direction; a working chamber formed within the hollow cylinder for receiving compressed air, the working chamber contacting an active surface of the piston, so that a lifting force acting on the piston can be controlled by means of the compressed air; and a space formed between an outer circumferential surface of the piston and an inner circumferential surface of the hollow cylinder.
  • the second aspect further relates to a positioning device with a base unit and a support unit, wherein the support unit is mounted on or on the base unit and is horizontally movable relative to the base unit and is adapted to support an object to be positioned.
  • a third aspect relates to a positioning device having a first structural unit and a second structural unit, which are mounted on or on each other and is movable relative to one another in a first coordinate and in at least one further coordinate.
  • the third aspect further relates to a measuring carriage for such a positioning device.
  • horizontal and vertical are to be understood as follows.
  • the term “horizontal” refers to a specified level in a defined frame of reference. Layers and directions that are parallel to this specified plane are called horizontal.
  • the defined plane can thus be defined independently of the earth's surface or of the gravitational field of the earth.
  • a straight line or direction is vertical if it is perpendicular to the specified (horizontal) plane.
  • at least one used on the support unit and fixed to the base unit reference system It can be provided that the support unit with respect to the base unit can be converted into a basic position in which the reference system fixed to the base unit and the reference system fixed to the support unit coincide.
  • An air bearing is a bearing in which an air cushion can be generated by means of compressed air.
  • compressed air ordinary air, ie a mixture of nitrogen, oxygen and other gases, or another gas or another gas mixture can be used.
  • nitrogen can be used, especially for applications in an artificial nitrogen atmosphere.
  • a ball joint interconnects two rigid bodies such that translations of the two bodies are blocked relative to each other, while pivoting movements about three linearly independent axes are allowed, at least within a certain pivotal range.
  • a ball joint is therefore characterized by its function and not by its special design.
  • a gimbal joint interconnects two rigid bodies such that translations of the two bodies relative to each other and pivot about a first axis are blocked, while pivotal movements about two linearly independent axes are allowed at least within a certain pivotal range.
  • a gimbal joint is therefore characterized by its function and not by its special design.
  • a one-dimensional linear bearing restricts the relative movement of two bodies to movements along a straight line.
  • a two-dimensional linear bearing restricts the relative movement of two bodies to movements in a plane.
  • Positioning devices of the type mentioned can be found in particular in the production of flat screens, for example, liquid crystal displays, application.
  • the object to be positioned may be an object to be processed, for example a preliminary stage of a flat screen.
  • the positioning device can be provided in particular for a fine positioning, by means of which, for example, deviations in the size or shape of the object can be compensated. For example, a wedge error of a plate-shaped object can be compensated by a slight tilting of the object.
  • the object to be positioned can also be a further positioning device.
  • a further positioning device From a plurality of positioning devices, each providing a certain number of degrees of freedom, a more complex positioning device with a greater number of degrees of freedom can be composed.
  • cross tables can be equipped with further degrees of freedom by mounting additional devices on the cross table. The result is a total structure that is heavy and bulky.
  • the overall structure may also, as it is composed of several components, be error prone.
  • the height of the structure can also contribute to positioning errors and measurement errors.
  • the positioning device is based on the object, the positioning device such that can be dispensed with an additional module for pivoting the object to be positioned about a horizontal axis.
  • the lifting unit according to the second aspect has the object of designing the lifting unit in such a way that it allows the picking up of high loads and at the same time can be controlled with high precision.
  • the positioning device is based on the object of equipping the positioning device with a measuring device for measuring the value of the first coordinate.
  • the object according to the first aspect is achieved in that between the base unit and the support unit one or more lifting units are arranged, each extending from the base unit to the support unit, wherein each of the lifting units is controllable such that one of the respective lifting unit associated vertical distance between the base unit and the support unit is controllable, so that a pivoting of the support unit about a horizontal axis is controllable relative to the base unit.
  • the arrangement of the lifting units between the base unit and the carrying unit allows a more compact, lighter, more robust and more precisely controllable design.
  • a plurality of lifting units that is to say at least two lifting units, are provided, these lifting units can be controlled independently of one another. This makes it possible to pivot the support unit about different horizontal axes. It may be provided that the angles about which the support unit is horizontally pivotable horizontally relative to the base unit are relatively small, for example less than one of the following angles: three degrees, one degree, one hundred seconds of arc, thirty seconds of arc and ten seconds of arc.
  • the lifting units thus make it possible to slightly tilt the support unit relative to the base unit.
  • the lifting units can be controlled pneumatically, electrically or electro-pneumatically.
  • the positioning device can be used in particular for the positioning of components to be machined or mounted in various production processes, for example for the production of LCD screens, wafers, printed circuit boards and integrated circuits.
  • the support unit may have a flat surface for supporting the object to be positioned.
  • flat objects for example plate-shaped substrates, can thus be stored stably on the support unit.
  • the carrying unit can thus be used as a table.
  • the support unit may further comprise one or more holders, with which the object to be positioned can be fastened to the support unit.
  • the lifting units can each have a retractable and retractable piston.
  • the piston can be moved in and out vertically.
  • the direction in which the piston is extendable is referred to as the stroke direction of the piston.
  • a vertical stroke direction enables on the one hand the realization of short strokes and thus allows the Use as short a piston as possible. On the other hand, it avoids unwanted torques and forces, especially when the base unit is mounted or set up so that the vertical coincides with the direction of gravity.
  • the lifting units may each further comprise a hollow cylinder in which the piston is mounted.
  • the hollow cylinder may, for example, be fastened to the base unit while the piston is fastened to the support unit.
  • the hollow cylinder may alternatively be attached to the support unit while the piston is attached to the base unit.
  • the triangle and the rectangle are not a component, but geometric terms that describe the arrangement of the lifting units.
  • the triangle and the rectangle may extend horizontally between the base unit and the support unit.
  • the triangle is advantageously an acute-angled triangle, for example an equilateral triangle. This promotes uniform loading of the three lifting units during operation and may be particularly advantageous if the three lifting units are identical or at least similar.
  • the use of more than three lifting units can also make it possible to at least partially correct local irregularities or a non-uniform mass distribution of the object to be supported. It may also allow to use a comparatively thin plate as a carrying unit.
  • more than four lifting units are provided, for example five, six, seven, eight or more than eight lifting units.
  • the lifting units can be arranged, for example, in the grid points of an imaginary two-dimensional horizontal grid.
  • the grid may be a grid with a square unit cell.
  • the lifting units provide three additional degrees of freedom, namely the three vertical distances between the base unit and the carrying unit assigned to the lifting units.
  • a vertical distance between the base unit and the support unit for example, the distance between a central point of the base unit and a central point of the support unit
  • an angle ⁇ tilt angle
  • a body-fixed vertical axis ie, a z-axis moving with the carrying unit, also referred to as a body-fixed z-axis
  • a horizontal angle ⁇ describing a pivot of the body-fixed z-axis about a vertical axis fixed relative to the base unit.
  • the tilt angle ⁇ and the horizontal angle ⁇ can be equivalently described by two tilt angles ⁇ ⁇ and ⁇ ⁇ , where ⁇ ⁇ is a rotation of the support unit to describes a first horizontal axis, for example an x-axis, and wherein ⁇ ⁇ describes a pivot about a second horizontal axis, for example a y-axis orthogonal to the x-axis.
  • the tilt angle ⁇ and the horizontal angle ⁇ are further equivalent to two of a total of three Euler angles describing the orientation of the support unit relative to the basic unit.
  • the third Euler angle is fixed or changeable depending on the embodiment; If it is changeable, it describes a pivoting of the carrying unit about the body-fixed z-axis.
  • the four-lift embodiment provides the same three degrees of freedom as the three-lift unit embodiment just described.
  • the position of the carrying unit relative to the base unit is statically overdetermined.
  • the rectangular configuration allows a particularly stable mounting of the carrying unit.
  • it can bring a somewhat more complex control of the four lifting units, since the four lifting units can not be controlled independently, to ensure that the four lifting units are evenly loaded.
  • it may be advantageous that at least two lifting units are provided and that for each lifting unit applies that the horizontal distances of the respective lifting unit to the other lifting units are each at least twice as large as a maximum stroke of the respective lifting unit. This means that relatively large strokes cause relatively small swings of the support unit.
  • the swivel angle can thus be controlled very precisely.
  • the lifting directions of the lifting units are preferably parallel to one another.
  • the positioning device comprises a carriage which is mounted on at least one linear bearing on a rail of the base unit, wherein the support unit is mounted on the carriage via a ball joint or via a gimbal joint.
  • the rail forms, together with the carriage, a linear guide device, by means of which the carrying unit is displaceable on a path defined in the horizontal plane.
  • the path is determined by the horizontal rail.
  • the path can be straight or curved.
  • the rail may be formed, for example, as a web.
  • a web may be attached to the base unit or integrally formed with the base unit.
  • the gimbal joint allows the support unit to pivot about a horizontal axis tangent or parallel to the rail.
  • the ball joint additionally allows a pivoting of the support unit about a vertical axis.
  • the pivoting about the tangential to the rail or parallel horizontal axis is, as already described, controlled by the one or more lifting units.
  • the carriage may have a planar first surface facing the rail, wherein between the rail and the first surface Linear bearing is formed.
  • the carriage may further comprise a support unit facing convex second surface, wherein between the second surface and the support unit, the ball joint or the universal joint is formed.
  • the second surface of the carriage may in particular be cylindrically convex or spherically convex.
  • the lifting units are attached to the support unit. They can in particular be rigidly attached. The lifting units thus move with the support unit as it moves along the rail. This makes it possible to move the support unit over any desired distances along the rail, assuming a corresponding rail length.
  • the lifting units are attached to the base unit. For example, they can be rigidly attached to it. In this case, the lifting units do not move with the support unit when the latter is displaced along the rail. This embodiment is particularly suitable for applications in which the support unit is to be moved horizontally only over short distances.
  • At least one horizontal linear bearing can be formed in each case between the lifting units and the basic unit.
  • the lifting units are thus displaced horizontally according to the guide direction of the rail, for example together with the support unit.
  • they may be pivotable about a defined by said ball joint vertical axis.
  • at least one linear bearing may be formed between the lifting units and the carrying unit.
  • the mentioned linear bearings can be designed in particular as air bearings.
  • the linear bearings each have a certain tolerance range with regard to horizontal pivoting of the support unit. These tolerances allow horizontal pivoting of the support unit in a certain relatively small angular range, in other words, slight tilting of the support unit relative to the base unit, for example in a range of minus one degree to plus one degree relative to the horizontal plane.
  • the positioning device may further comprise one or more linear motors, which are adapted to exert on the support unit a directed parallel to a guide direction of the rail driving force.
  • a first and a second of these linear motors are arranged on opposite sides of the rail.
  • the two linear motors can be controlled in such a way that together they produce a combined drive force directed in the guide direction of the rail and additionally or alternatively produce a vertical torque.
  • the support unit can be pivoted about a vertical axis.
  • the first and the second linear motor are independently controllable.
  • the first and the second linear motor can be controlled in such a way that they actively counteract the yawing of the carriage and thus reduce or completely suppress the yaw.
  • Yawing is an undesirable swinging of the support unit about a vertical axis.
  • the support unit is mounted on the base unit via a ball joint and is pivotable relative to the base unit about a rotation axis fixed relative to the support unit.
  • the support unit is thus pivotable about a body-fixed axis of rotation.
  • the body-fixed axis of rotation can in particular be a vertical body-fixed axis of rotation.
  • the support unit is not necessarily displaceable horizontally relative to the base unit.
  • the rail may have a translational degree of freedom less.
  • a waiver of this translatory degree of freedom can be opposed by an increased pivoting range for pivoting about said fixed axis of rotation relative to the support unit.
  • the support unit and with it said rotation axis is pivotable only by a relatively small tilt angle ⁇ against a fixed relative to the base unit vertical axis, for example by not more than 1 degree, 2 degrees or 3 degrees ,
  • the lifting units are advantageously attached to the base unit.
  • the lifting units are thus not moved along with the support unit.
  • At least one linear bearing can be formed in each case between the lifting units and the carrying unit.
  • the linear bearing allows the horizontal movement of the support unit relative to the respective lifting unit.
  • the linear bearing is advantageously tolerant to slight horizontal pivoting of the support unit relative to the base unit.
  • Slight pans are, for example, no more than one degree, two degrees or four degrees pans.
  • the positioning device may further include one or more motors configured to apply a vertical torque to the support unit. The torque can be transmitted for example via a vertical shaft. Alternatively or additionally, one or more linear motors or plunger coil motors may be used to generate tangential forces that provide the vertical torque.
  • the positioning device can be integrated in particular in a cross table.
  • the object according to the second aspect is achieved in that the intermediate space between the piston and the hollow cylinder has an air bearing area, which can be traversed by compressed air, so that between the hollow cylinder and the piston, an air cushion is generated. With the help of the air cushion succeeds a low-friction and at the same time stiff bearing of the piston.
  • the gap may further include: a sealing area communicating with the working chamber; and at least one outflow region formed between the air bearing region and the sealing region, which is connected to at least one air outlet via at least one channel passing through the hollow cylinder so that both compressed air from the air bearing region and leakage air can be removed from the sealing region via the outflow region.
  • the pressures in the working chamber and in the air bearing area can therefore be controlled essentially independently of one another.
  • the pressure profile in the air bearing area can be controlled, for example, by controlling a supply pressure of the air bearing.
  • the pressure in the working chamber can be controlled by controlling a pressure applied to the working chamber. It can be provided that the at least one outflow region extends along a circumferential line of the inner circumferential surface of the hollow cylinder.
  • the circumferential line is a self-contained, for example annular, contour on the lateral surface, which runs around the cavity defined by the hollow cylinder. This favors uniform air removal along the perimeter.
  • the circumferential line may in particular lie in a plane perpendicular to the stroke direction. It can further be provided that the inner circumferential surface of the hollow cylinder at the at least one outflow region has a groove. Through the groove of the outflow is expanded radially outward. The width of the groove determines the width of the outflow area.
  • the groove has a width which is greater than a minimum distance between the outer circumferential surface of the piston and the inner circumferential surface of the hollow cylinder.
  • the outflow area is thus formed as a widening of the gap.
  • the outflow area is thus sufficiently spacious to largely prevent overflow of compressed air from the air bearing area into the sealing area or vice versa.
  • the channels can be designed, for example, as holes.
  • the channels can lead outwards in a star shape from the groove. They can, for example, flow into the atmosphere or be part of a closed cycle.
  • the groove may be, for example, twice as wide as a minimum distance between the outer surface of the piston and the inner circumferential surface of the hollow cylinder in the air bearing area and in the sealing area.
  • the at least one channel and the at least one air outlet may have such large cross sections that together they have a throttling effect which is negligible compared to a throttle effect of the air bearing area and compared to a throttling effect of the sealing area.
  • the pressures in the intermediate region are decoupled in this way from the pressures downstream of the outflow region.
  • the pressure in the outflow area may be the ambient pressure or the atmospheric pressure.
  • the lifting unit can be equipped with a drive device for generating an additional lifting force.
  • the drive device can serve a fine control of the piston.
  • the lifting unit can be operated, for example, such that the effective area of the piston is acted upon by a pressure which exactly or approximately compensates for an opposing force acting on the piston, for example a weight force.
  • an additional lifting force counteracting the pneumatic force or assisting it can then be applied in order to precisely control the piston.
  • the drive device may, for example, comprise an electric motor. This is based on the knowledge that the electric current flowing through the electric motor can be controlled and regulated faster and more precisely than the pressure in the working chamber.
  • the electric motor may include a magnet and a coil, both of which are disposed within the hollow cylinder.
  • the electric motor may be, for example, a voice coil motor. It can be provided that the coil is fixedly mounted with respect to strokes of the piston on the hollow cylinder, while the magnet is mounted with respect to strokes of the piston fixed to the piston.
  • the magnet may in particular be a permanent magnet.
  • the mounting of the coil on the hollow cylinder simplifies the electrical contact of the coil.
  • the coil and the magnet can in particular each be rigidly connected to the hollow cylinder or to the piston.
  • the lifting unit may have a column extending in the lifting direction, on which the magnet or the coil or both the magnet and the coil are mounted. Both the magnet and the coil may be at least partially disposed within the working chamber.
  • an air bearing surface On an end face of the lifting unit, an air bearing surface may be formed.
  • An air bearing surface is a surface of a body intended to support the body via an air cushion on a surface of a second body. The two surfaces are also referred to as air bearing surface and air bearing mating surface.
  • An air bearing surface may have a compressed air opening, for example a nozzle. The compressed air opening introduces compressed air into a space between the air bearing surface and the air bearing mating surface to form the air bag.
  • the air bearing surface may be pivotable relative to the hollow cylinder or relative to the piston by at least one axis orthogonal to the stroke direction.
  • the lifting unit is therefore more flexible, in particular as a lifting unit between two mutually pivotable bodies.
  • the lifting unit described here can be used in particular in one of the positioning devices described here.
  • one or more lifting units can be arranged between the base unit and the carrying unit, wherein each of the lifting units is controllable in such a way that a vertical distance between the base unit and the carrying unit assigned to the relevant lifting unit is controllable, with which Pivoting the support unit about a horizontal axis relative to the base unit is controllable.
  • the positioning device solves the task on which it is based in that it has a measuring device for measuring the first coordinate, wherein the measuring device has a measuring slide which is coupled to the two structural units such that the measuring slide:
  • the measuring carriage remains immovable relative to the first structural unit with changes in the coordinates to be measured, and immovable relative to the second structural unit when the other coordinates change.
  • the position of the measuring carriage relative to the first structural unit thus corresponds to the current value of the first coordinate to be measured.
  • This position in turn can be translated into a measuring signal, for example into an optical or electrical measuring signal.
  • the first unit is the basic unit and the second unit is the support unit.
  • the second unit is the basic unit and the first unit is the support unit.
  • the first coordinate indicates a pivoting of the second structural unit about a fixed relative to the second structural unit vertical axis of rotation and one of the other coordinates indicates a pivoting of the axis of rotation relative to the first structural unit.
  • the measuring device is thus able to measure pivoting movements of the second structural unit relative to the first structural unit about the vertical axis of rotation fixed relative to the second structural unit.
  • the measuring carriage is supported so as to remain stationary relative to the first structural unit (for example, the base unit) when the second structural unit (for example, the support unit) is pivoted relative to the first structural unit about the vertical rotational axis fixed relative to the second structural unit However, it moves with the second unit when the second unit is pivoted relative to the first unit about an axis perpendicular to said axis of rotation axis.
  • the measuring slide thus filters out the degree of freedom to be measured from the various degrees of freedom, in this case the pivoting of the second structural unit (for example the carrying unit). unit) relative to the first structural unit (for example the basic unit) about the fixed relative to the second structural unit vertical axis of rotation.
  • the position of the measuring carriage relative to the second unit thus corresponds to an angle by which the second unit is pivoted.
  • Measuring the pivots in the reference frame secured to the second assembly may facilitate control of movement of the second assembly relative to the first assembly.
  • the first coordinate indicates a horizontal displacement of the second structural unit relative to the first structural unit and one of the further coordinates indicates a pivoting of the second structural unit relative to the first structural unit about a horizontal axis.
  • a horizontal linear bearing can be formed between the measuring carriage and the second structural unit.
  • the horizontal linear bearing binds the measuring carriage to the second structural unit (for example to the support unit), but allows the second structural unit to be pivoted relative to the measuring slide about the vertical axis fixed relative to the second structural unit. It can be provided that only a relatively small pivoting range is allowed, so that the pivoting movement can be locally approximated by a linear movement (tangential motion). However, it can also be used a curved bearing, which corresponds to a circular arc.
  • the horizontal linear bearing may be a magnetically biased or magnetically biased air bearing.
  • the measuring carriage or the second structural unit or both can each have at least one magnet, which is provided to generate an attractive force between the measuring carriage and the second structural unit.
  • the measuring carriage is arranged on a horizontal rail of the second structural unit.
  • the rail is used to guide the measuring slide. If the coordinate to be measured is an angle, and the angle range of interest is sufficiently small, then the rail can be straight. For larger angular ranges, a circularly curved rail, which corresponds to a circular arc, may be advantageous.
  • the measuring carriage is coupled via a ball joint or via a universal joint to the first structural unit. This prevents that the measuring carriage moves with respect to the measured vertical swiveling of the second unit with the second unit. However, the ball joint or the cardan joint allows the measuring carriage to move with it with regard to horizontal pivoting of the second unit.
  • the ball joint or universal joint is advantageously arranged on a horizontal axis of rotation of the second structural unit. Along such a rotation axis associated with the horizontal pivoting vertical distance changes between the second unit and the first unit are particularly low, so that the ball joint or the universal joint of the measuring device can be made particularly small.
  • the measuring carriage may be coupled to the first structural unit via a two-dimensional linear bearing, wherein the two-dimensional linear bearing permits vertical and horizontal movement of the measuring carriage relative to the first structural unit.
  • the linear bearing provides sufficient clearance, can be dispensed with the aforementioned ball joint or universal joint of the measuring device.
  • the linear bearing allows the measuring slide to move with the second structural unit during vertical movements of the second structural unit. Such a vertical movement can be effected for example by a synchronous retraction or extension of the lifting units described in connection with the first aspect.
  • the linear bearing may be a magnetically biased or magnetically preloaded air bearing. The linear bearing thus binds the measuring carriage with respect to the first coordinate to be measured to the first unit.
  • the measuring carriage is coupled via a ball joint or via a universal joint to a coupling body and the coupling body is coupled via a two-dimensional linear bearing to the first unit.
  • the measuring carriage may have a first scale and the second unit may have a second scale, wherein a measuring head is provided which is capable of a dependent on a shift of the second scale relative to the first scale Generate the appropriate measurement signal.
  • the measuring carriage may have a first graduation pitch and the second modular unit may have a second graduation graduation, wherein the first and the second graduation graduation overlap at least partially and are suitable for modulating a light intensity as a function of the coordinate to be measured.
  • the measuring carriage may further include a sensor for measuring the modulated light intensity.
  • the sensor may include, for example, one or more photodiodes.
  • Figure 1 is an oblique view of a first example of a positioning device
  • Figure 2 is a further oblique view of the positioning device of Figure 1;
  • Figure 3 is a side view of the positioning device of Figure 1;
  • Figure 4 is an oblique view of a second example of a positioning device
  • Figure 5 is an oblique view of a basic unit of the positioning device of Figure 4.
  • Figure 6 is an oblique view of a support unit of the positioning device of Figure 4.
  • Figure 7 is a first side view, a second side view, a plan view, a
  • Figure 8 is an enlarged view of the longitudinal section of the lifting unit of Figure 7;
  • Figure 9 is a front view, a side view, a rear view, a top view and an oblique view of a measuring device of the positioning device of Figure 4;
  • FIG. 10 is an exploded view of a measuring device;
  • Figure 1 1 a ball joint of the measuring device of Figure 10;
  • Figure 12 is an exploded view of the measuring device of Figure 10
  • Figure 13 is an exploded view of the measuring device of Figure 10;
  • Figure 14 is an oblique view of an example of a positioning device
  • Figure 15 is an oblique view of the positioning device of Figure 14;
  • FIG. 16 shows a detailed view of the positioning device from FIG. 14.
  • FIGS. 1 to 3 show a first example of a positioning device 10.
  • the positioning device 10 has a base unit 12 and a carrying unit 14.
  • the carrying unit 14 is removed in order to release the view of a gap 16 formed between the base unit 12 and the carrying unit 14.
  • the support unit 14 is mounted on or on the base unit 12 such that it is horizontally movable relative to the base unit 12.
  • the carrying unit 14 is adapted to carry an object to be positioned (not shown).
  • the object to be positioned may, for example, be another (different or identical) positioning device or, for example, an object to be processed.
  • one or more lifting units are arranged between the base unit 12 and the support unit 14.
  • a total of three lifting units 18, 20, 22 are provided.
  • Each of the lifting units 18, 20, 22 is controllable in such a way that a vertical distance between the base unit 12 and the carrying unit 14 assigned to the relevant lifting unit 18, 20, or 22 can be controlled.
  • a horizontal pivoting of the support unit 14 is controllable relative to the base unit 12.
  • the just mentioned horizontal and vertical directions are defined with respect to the basic unit 12. They can be coordinated by a fixed coordinate with respect to the basic unit 12.
  • ny system xyz In the example shown, the xy plane is a horizontal plane while the z axis perpendicular to the xy plane is a vertical axis.
  • the carrying unit 14 is displaceable in the y-direction.
  • the support unit 14 is horizontally movable.
  • the support unit 14 is also horizontally pivotable. This means that it is pivotable about at least one horizontal axis.
  • the permitted horizontal axes of rotation for the pivoting movement are determined by the lifting units 18, 20, 22 associated with vertical distances.
  • the aforementioned vertical distances, or in other words, the state of the three lifting units 18, 20, 22, can lend a reference to the support unit 14 fixed plane, within which the allowed axes of rotation are controllable by the lifting units pivotal movement.
  • This level is also referred to as a body-fixed horizontal plane. As a body-fixed in this application, each point and each direction are designated, which are stationary with respect to the support unit 14, so move with the support unit 14.
  • the lifting units 18, 20, 22 each have a retractable and retractable piston.
  • the pistons are each vertical, so here in the z-direction retractable and extendable.
  • the length by which the respective piston (for example the piston of the lifting unit 18) has been extended determines the vertical distance between the carrying unit 14 and the base unit 12 assigned to the lifting unit in question (in the example in question, the vertical distance assigned to the lifting unit 18) ).
  • the respective vertical distance can be defined in each case as the distance between a fixed point of the base unit 12 and a fixed point of the support unit 14 arranged vertically above or below it.
  • the lifting units 18, 20, 22 are arranged in the vertices of an acute-angled triangle.
  • the acute-angled triangle may in particular be an equilateral triangle.
  • the carrying unit 14 can pivot about a side of the triangle connecting the lifting unit 20 with the lifting unit 22.
  • the support unit 14 can pivot about a side connecting the lifting unit 22 with the lifting unit 18 side of the triangle.
  • the carrying unit 14 can be pivoted about a side of the triangle connecting the lifting unit 18 to the lifting unit 20.
  • a total of four lifting units similar to the lifting units 18, 20, 22 are provided.
  • the four lifting units can be arranged in the vertices of a rectangle.
  • the support unit 14 can then pivot about any axis that connects a corner of the rectangle with another corner of the rectangle.
  • Each of the lifting units 18, 20, 22 has a maximum lift.
  • the maximum stroke is the difference in length between the position of the piston when fully extended and the position of the piston when fully retracted.
  • the maximum stroke may be small compared to the mutual distances of the lifting units.
  • the horizontal distance of each lifting unit 18, 20, 22 is at least twice as large as the maximum stroke of the relevant lifting unit 18, 20 or 22. This means that the carrying unit 14 only within a small angular range relative to the base unit 12th is horizontally swiveling.
  • the maximum stroke of each lifting unit 18, 20, 22 may for example be between one millimeter and one centimeter.
  • the mutual distances of the lifting units 18, 20, 22 may be, for example, between twenty centimeters and two meters.
  • the lifting units 18, 20 22 are horizontally displaceable relative to the base unit 12. This allows the lifting units 18, 20, 22 to move together with the support unit 14 horizontally relative to the base unit 12.
  • the lifting units 18, 20, 22 each have one of the support unit 14 facing support surface 24, 26, 28. In the example shown, these surfaces are each a surface of an end plate of a hollow cylinder of the respective lifting unit 18, 20 or 22.
  • the lifting units 18, 20, 22 can in their respective support unit 14 facing surface 24, 26, 28 fixedly connected to the support unit 14 be, for example via suitable fixing devices, for example screws or pins.
  • the support unit is to be installed or mounted obliquely relative to the ground, that is, when said horizontal plane of the base unit 12 (in Figure 1 to 13, the xy plane) is not horizontal, that is not perpendicular to the gravitational field Earth-oriented.
  • the lifting units 18, 20, 22 are not fixed to the support unit 14. Your the carrying unit 14 facing surfaces 24, 26, 28 may form Aufla- surfaces for supporting the support unit 14.
  • the base unit 12 is set up or mounted horizontally with respect to the earth, so their horizontal plane (the xy plane in the drawings) is oriented parallel to the earth's surface or, in other words, perpendicular to gravity.
  • Such a setup is particularly advantageous since it allows the weight of the support unit 14 and any loads supported on the support unit 14 to be dissipated via the pistons of the lifting units 18, 20, 22, the direction of extension and retraction (piston longitudinal direction or piston longitudinal axis) of the pistons then parallel to the dissipated force.
  • the carrying capacity of the positioning device 10 can be maximized by the described horizontal installation.
  • a loose mounting of the support unit 14 on the lifting units has the advantage of being able to remove the support unit 14 as uncomplicated as possible from the base unit 12, for example, to replace it with another support unit (not shown).
  • Various carrying units may be provided which are set up for different loads to be carried.
  • the carrying unit 14 has a bearing surface 30.
  • the support surface 30 is flat.
  • the object to be supported (not shown) can be placed, or it can be fixed to it.
  • the flat support surface 30 is particularly suitable for supporting planar objects, for example flat screens, semiconductor substrates, wafers, printed circuit boards and solar cells.
  • the overall flat design of the positioning device 10 also favors its use as a module of a more complex positioning device, for example as a structure or as a carrier, a linear guide device which provides a further degree of translational freedom (for example in the x-direction).
  • the support unit 14 has two horizontal translational degrees of freedom relative to the base unit 12, namely translations in the x-direction and in the y-direction.
  • a linear guide device is integrated, which restrict the horizontal translational degrees of freedom to a single. The linear guide device will be explained below with reference to FIGS. 1 to 3.
  • the base unit 12 has a rail 32.
  • the rail 32 extends horizontally in the space 16 between the base unit 12 and the support unit 14. In the example shown, the rail runs in a straight line, for example in the y-direction. Alternatively, the rail 32 may be curved, for example, a closed loop or a Form a circular arc.
  • the rail 32 may be formed integrally with the base unit 12. In the example shown, the rail 32 is formed as a web extending in the y-direction and having a rectangular, for example square, cross-section.
  • the rail 32 has two opposite side surfaces 34 and 36.
  • a respective carriage 38 or 40 is displaceably mounted via a linear bearing in the guide direction of the rail (in this case the y-direction).
  • the linear bearings can each be designed as air bearings.
  • compressed air can be introduced into a gap between the rail 32 and the respective carriage 38 or 40 in order to form an air cushion in this gap.
  • the support unit 14 is pivotally mounted on the two slides 38 and 40 each via a ball joint.
  • the two ball joints can also be considered as a single ball joint, which allows pivoting of the support unit 14 relative to the two slides 38, 40 and blocked translations of the support unit 14 relative to the carriage 38 and 40.
  • the two slides 38 and 40 can be considered as a single carriage, which is slidably mounted on the rail 32.
  • the carriage 38 and the carriage 40 each have a planar surface facing the rail and a convex, for example, spherically convex surface facing away from the rail.
  • the flat side surfaces 34 and 36 of the rail define, together with the flat surfaces of the carriage 38 and the carriage 40, the said linear bearings, wherein the two linear bearings can be regarded as a single linear bearing.
  • the two convex surfaces of the carriages 38 and 40 each face a concave surface of a carrier 42 and a carrier 44.
  • the said concave and convex surfaces together define the ball joint between slide and carriers.
  • the ball joint may be formed as an air bearing.
  • the carriers 42 and 44 are each rigidly or elastically connected to the support unit 14 or formed integrally with it.
  • the lifting units 18, 20, 22 each have a base 46, 48, 50.
  • the pedestals 46, 48, 50 are each mounted displaceably on or on the base unit 12.
  • Between Sockets 46, 48, 50 and the base body 12 each have a linear bearing is formed.
  • these linear bearings can each be an air bearing.
  • the support unit 14 is thus displaceable along the rail 32.
  • the lifting units 18, 20, 22 as well as the carriages 38, 40 and the carriers 42, 44 are displaced with such a displacement with the support unit 14.
  • the lifting units 18, 20, 22 are not moved, but remain stationary with respect to the base unit 12.
  • the carrying unit 14 is displaceable only within a relatively small permitted area along the rail 32, since it must be ensured that the carrying unit 14 remains mounted on or on each of the lifting units 18, 20, 22.
  • the lifting units 18, 20, 22 in conjunction with the ball joint between the support unit 14 and the carriage 38, 40 allow the support unit 14 to pivot relative to the base unit 12 within an angular range determined by the ball joint.
  • the carrying unit 14 is pivotable in particular about an axis parallel to the x-axis, an axis parallel to the y-axis and an axis parallel to the z-axis.
  • the pivoting about the axis parallel to the z-axis and the displacement in the y-direction represent two horizontal degrees of freedom.
  • the pivoting about the axis parallel to the x-axis and the axis parallel to the y-axis represent two vertical degrees of freedom the carrying unit 14.
  • a vertical degree of freedom namely a vertical displacement of the support unit 14 relative to the base unit 12, which can be effected for example by a synchronous control of the three lifting units 18, 20, 22, so for example by synchronous retraction or extension of the piston Lifting units, whereby the support unit 14 is moved along the z-axis, without their inclination angle relative to the base unit 12 changes.
  • the linear bearing between the slide 38, 40 in addition to the movement in the guide direction of the rail (y-direction) also allows a vertical displacement on the rail (in the z-direction).
  • the linear bearing between the rail 32 and the carriage 38 and the linear bearing between the rails 32 and the carriage 40 is each a two-dimensional linear bearing.
  • a first linear motor 52 and a second linear motor 54 are provided which are each capable of imparting to the support unit 14 a drive force parallel to the guide unit. direction of the rail (here the y-direction) exercise. It is noted that each one of the two motors 52 and 54 is capable of applying to the support unit 14 a vertical torque with respect to the ball joint. The torque exerted by the first motor 52 and by the second motor 54 add up to a total torque. In particular, the two torques can add up to zero. In the symmetrical structure shown here, this is the case when the forces generated by the two motors 52 and 54 are the same size and the same direction.
  • the two motors 52, 54 can be controlled synchronously in order to minimize the said resulting total vertical torque as far as possible and to achieve a pure linear movement (here in the y-direction). However, the two motors can also be controlled individually and optionally asynchronously in order to generate a vertical torque, which counteracts a detected yawing movement (yaw) of the carrying unit 14.
  • a measuring device may be provided which measures the yaw and transmits a corresponding measurement signal to an electronic control unit (not shown).
  • the electronic control unit can be provided to evaluate the measurement signal and to control the two motors 52, 54 in such a way that they counteract yawing. Alternatively or additionally, a desired rotation about the vertical axis can be generated.
  • the two motors 52, 54 each have a certain amount of play to allow a slight tilting of the support unit 14 relative to the base unit 12.
  • lifting units 18, 20, 22 are provided. However, it may be advantageous to provide more than three, for example four, five, six or more than six lifting units.
  • the weight of a load on the support unit object can be distributed in the way uniformly on the lifting units.
  • the use of a larger number of lifting units allows the design of the support unit as a relatively thin, flexible plate. Individual control of the lifting units then makes it possible to compensate not only wedge errors but also higher-order form errors of the object.
  • FIGS. 4, 5 and 6 show a second example of a positioning device 10.
  • the positioning device 10 has a base unit 12 and a carrying unit 14 mounted on or on the base unit 12. Similar to the positioning device described with reference to FIGS. 1 to 3, a plurality of lifting units are arranged between the base unit 12 and the carrying unit 14, each of which is controllable in such a way that a vertical distance between the base unit 12 and 12 assigned to the relevant lifting unit is the support unit 14 is controllable. As a result, a horizontal pivoting of the support unit 14 is controllable relative to the base unit 12.
  • the lifting units are hidden in Figure 4 by the support unit 14 and not visible.
  • FIG. 5 shows only the base unit 12.
  • FIG. 6 shows only the carrying unit 14.
  • the carrying unit 14 is shown "standing upside down" in FIG.
  • the base unit 12 and the support unit 14 are (as in the positioning device described with reference to FIGS. 1 to 3) designed as two substantially mutually parallel horizontal plates which are tiltable against each other within a limited angular range.
  • the support unit 14 has three recesses 62, 64, 66 arranged at the corner points of an acute-angled triangle, in each of which one of the lifting units (hidden in FIG. 4, not shown in FIG. Within the recesses 62, 64, 66 each have a linear bearing is provided so that the support unit 14 is pivotable relative to the lifting units and the base unit about a body-fixed vertical axis 70 of the support unit 14.
  • the support unit 14 has only the following degrees of freedom relative to the base unit 12: vertical displacements (translations in the z-direction), inclination of the body-fixed rotation axis 70 starting from a vertical axis 68 ("theta tilting"), pivoting of the support unit 14 and thus pivoting the body-fixed axis of rotation 70 about the vertical axis 68 and pivoting of the support unit 14 about the body-fixed axis of rotation 70.
  • the three mentioned swivels describe the orientation of the support unit 14 relative to the base unit 12. They are equivalent to three Euler angles.
  • the positioning device 10 in FIGS. 1 to 3 additionally has a horizontal degree of freedom, namely translations in the y-direction.
  • a ball joint or a gimbal joint (not shown) is provided, via which the support unit 14 is coupled to the base unit 12.
  • the ball joint between a support unit 14 facing surface 72 of a central vertical column 74 is formed.
  • the ball joint may in particular be a spherical air bearing.
  • the maximum permitted tilt angles ⁇ can be relatively small. For example, it may be provided that the tilt angle ⁇ is limited to values between zero degrees and three degrees. With such small allowable tilt angles, it is possible between the lifting units and each of the support unit 14 to provide a linear bearing having sufficient play to allow the support unit 14 to tilt from the vertical axis 68 by an angle ⁇ in said (small) allowable angular range.
  • the lifting units are each provided with a joint (see Figure 7 and the associated description).
  • the joint can be arranged, for example, between the linear bearing on the one hand and the piston or the hollow cylinder of the lifting unit on the other hand.
  • the allowable angular range for pivoting the support unit 14 about the body-fixed axis of rotation 70 may also be quite small, for example minus two degrees (first extremal pitch) to plus two degrees (two extreme pitch). In the example shown, this pivoting range is limited by four elongated holes 76 which are provided in the carrying unit 14. In each of the slots 76, a vertical pin 78 is arranged in each case. The carrying unit 14 can thus be pivoted about the body-fixed axis 70 from a first stop position into a second stop position.
  • the lifting units are preferably fixed to the base unit 12, so that they are not moved with the support unit 14.
  • edge regions, for example outer edges, of the carrying unit 14 are mounted on the base unit 12, for example via spherical bearings in conjunction with vertical linear bearings.
  • the spherical bearings and vertical linear bearings can each be designed as air bearings.
  • the ball joint described above, which couples the carrying unit 14 to the central column 74 of the base unit 12, can be dispensed with.
  • a plurality, for example three or four, joints and linear bearings may be provided along a horizontally extending outer circumference of the support unit 14. These hinges and linear bearings may permit pivoting as well as vertical displacement of the support unit 14 relative to the base unit 12 and block other motions.
  • the joints and linear bearings can each have one or more air bearings.
  • FIGS. 7 and 8 show an example of a suitable lifting unit 18.
  • the other lifting units mentioned above may be identical in construction to the lifting unit 18 described here.
  • the lifting unit 18 has a hollow cylinder 84 and a piston 86 mounted inside the hollow cylinder 84 (see FIG. 8).
  • the piston 86 can be moved in and out in a stroke direction (the image vertical in FIG. 8).
  • a working chamber 88 is formed for receiving compressed air.
  • the working chamber 88 contacts an active surface 90 of the piston 86.
  • the intermediate space 96 has an air bearing area 98 and a sealing area 100.
  • the air bearing area 98 can be traversed by compressed air, so that between the hollow cylinder 84 and the piston 86, an air cushion is generated. During operation of the lifting unit 18, the air cushion ensures that the piston can be moved in and out practically without friction.
  • the sealing area 100 communicates with the working chamber 88. Providing a seal in the sealing area 100 to prevent a creeping release of compressed air from the working chamber 88 via the sealing area 100 would entail an undesirable frictional effect between the piston 86 and the hollow cylinder 84. On such a seal is therefore omitted.
  • a discharge area 102 is formed between the air bearing area 98 and the sealing area 100.
  • the outflow region 102 is via at least one channel (not visible) passing through the hollow cylinder with at least one air outlet (not Visible), so that both compressed air from the air bearing area 98 and leakage air from the sealing area 100 can be discharged via the outflow area 102.
  • the outflow region 102 extends along a circumferential line of the inner circumferential surface 94 of the hollow cylinder 84. The circumferential line lies in a direction perpendicular to the stroke direction plane.
  • the outflow region is defined by a groove 104 of the inner circumferential surface 94 of the hollow cylinder 84.
  • the width of the groove so here their dimension in the stroke direction, is significantly greater than the distance between the outer circumferential surface 92 of the piston 86 and the inner circumferential surface 94 of the hollow cylinder 84.
  • said channels, the outflow area 102 with the one or connect the multiple air outlets such a large total cross-section that the compressed air from the air bearing area 98 and the leakage air from the sealing area 100 are fed to the air outlet without significant throttling effect.
  • the air outlet or the air outlets may, for example, open into an environment 106 of the lifting unit 18.
  • a lifting force can be generated, which can be used, in particular, to counteract a weight force acting on the piston 86, so that the lifting force compensates the weight force. As already mentioned, this may require a comparatively large lifting capacity.
  • the lifting force may be, for example, more than 1,000 Newton.
  • a plunger coil motor is provided in the lifting unit 18, which is capable of generating an additional lifting force.
  • the voice coil motor can be used to more precisely balance the weight force acting on the piston 86 than would be possible only by pneumatic means.
  • the plunger motor can also be used to extend or retract the piston with high precision.
  • the corresponding vertical distance between the base unit 12 and the support unit 14 (see the description of FIGS. 1 to 6) is precisely controllable in this way.
  • a signal from a measuring system integrated into the lifting unit can be used to control the dipping coil motor.
  • the voice coil motor has one or more magnets 108 as a conclusion.
  • the magnets 108 may be permanent magnets or paramagnets. In the example shown, the magnets 108 are iron sleeves.
  • the one or more magnets 108 are connected to the piston 86 via a magnetic carrier 110 so as to move with the piston 86 when the piston 86 is retracted or extended.
  • the Dive coil motor also has a first coil 1 12 and a second coil 1 14.
  • the coils 1 12 and 1 14 each rotate around the common longitudinal axis of the piston 86 and the hollow cylinder 84.
  • the coils 1 12 and 1 14 are wound around a bobbin 1 16 and connected via the bobbin 1 16 with the hollow cylinder 84 such that they are stationary with respect to the hollow cylinder 84, when the piston 86 is retracted or extended.
  • a coil 1 12, 1 14 flowing electrical current can be generated.
  • the electric current interacts with the magnetic field generated by the one or more magnets 108, generating a Lorentz force in the stroke direction.
  • the working chamber 88 is supplied with compressed air from a compressed air source (not shown).
  • Compressed air is supplied to the air bearing region 98 from the same or another compressed air source via a feed channel (not visible), so that the air cushion forms in the air bearing region 98.
  • the compressed air from the air bearing area 98 is discharged via the outflow area 102 and the one or more channels leading out from the discharge area 102.
  • compressed air flows as leakage air from the working chamber 88 via the sealing region 100 into the discharge region 102 and from there together with the compressed air from the air storage region 98 into the environment 106.
  • the lifting unit 18 has a support body 1 19 at one end.
  • a surface 120 of the support body 1 19 forms a support surface of the lifting unit 18.
  • the support surface 120 serves to transmit a lifting force to another body, for example to the base unit 12 or the support unit 14.
  • the support surface 120 is designed as an air bearing surface. In this example, it is flat and horizontal, that is orthogonal to the stroke direction.
  • compressed air is supplied via a supply line 122 and further via a longitudinal bore 124 into a central compressed air outlet opening 126, from where the compressed air flows radially outward, whereby between the support surface 120 and, for example, the support unit 14 or the base unit 12 (see FIGS to 6) an air cushion is formed.
  • One or more magnets 128 can be arranged laterally of the support surface 120 (see FIG. 7). About these magnets 128, the air bearing formed on the support surface 120 is magnetically biased.
  • the support body 1 19 is pivotally coupled to the piston 86 via a hinge 121.
  • the hinge 121 may be a ball joint or a gimbal joint. Within the joint 121, an air cushion can be generated.
  • the hinge 121 makes it possible, for example, to compensate for alignment errors and to allow a tilt of the support unit 14 relative to the base unit 12.
  • the lifting unit 18 also has a measuring device 1 18 for measuring the position of the piston 86 relative to the hollow cylinder 84.
  • the measuring device is capable of generating a measuring signal which indicates the length by which the piston 86 is extended.
  • the measuring device 1 18 may, for example, have two each extending in the stroke direction Strichilleren, wherein a first of the two Strichilleren on the hollow cylinder 84 and a second of the two Strichannonen on the piston 86 is fixed.
  • the lifting unit 18 can be controlled as follows, for example. First, a coarse positioning of the piston 86 is made by applying a suitable pressure to the working chamber 88. To compensate for a base load, a precise pressure can be set, for example by measuring the pressure in the working chamber 88 by means of a manometer. Thereafter or at the same time, the drive device is actuated as a function of the measuring signal of the measuring device which indicates the extension length, in order to minimize a deviation of the actual extension length from a desired extension length. In the example shown, the one applied to the plunger motor electrical voltage or a current flowing through the plunger motor current is controlled to minimize the deviation from the desired length. In addition, it may be provided that the pressure in the working chamber 88 is pneumatically controlled in dependence on the current flowing through the motor electrical current such that this current is minimized.
  • the positioning device 10 shown in FIGS. 4, 5 and 6 is further equipped with a measuring device 130 for measuring pivoting of the carrying unit 14 relative to the base unit 12.
  • the measuring device 130 will be explained in more detail below with reference to FIGS. 4 and 9 to 13.
  • the measuring device 130 is capable of measuring pivoting of the support unit 14 relative to the base unit 12 about the vertical axis of rotation 70 fixed relative to the support unit.
  • the body-fixed axis of rotation 70 has two degrees of freedom with respect to the basic unit 12, namely the tilt angle (polar angle) ⁇ and a (not shown in the drawings) horizontal angle ⁇ .
  • the orientation of the support unit 14 relative to the base unit 12 can be unambiguously described by the indication of the direction of the body-fixed axis of rotation 70 (for example by specifying said angles ⁇ and ⁇ ) and a further angle ⁇ (not shown), wherein the further angle ⁇ describes a pivoting of the support unit 14 relative to the base unit 12 about the body-fixed axis of rotation 70.
  • the orientation of the support unit 14 relative to the base unit 12 can be described by the specification of an angle ⁇ ⁇ and an angle ⁇ ⁇ , where ⁇ ⁇ measures a pivot around a space-fixed x-axis and ⁇ ⁇ a pivot about a space-fixed y-axis , It should be noted that the pivoting about the x-axis and the pivoting about the y-axis do not commute and therefore it is also necessary to state in which order the two swivels are executed. Only for very small swivel angle, the order is irrelevant.
  • the measuring device 130 has a measuring carriage 132.
  • the measuring carriage 132 is mounted on the base unit 12 and on the support unit 14 in such a way that it is firmly fixed relative to the base unit 12 when the support unit 14 is pivoted relative to the base unit 12 about the body-fixed vertical axis of rotation 70, but it is in contact with the support unit 14 moved when the support unit 14 is pivoted relative to the base unit 12 about a relative to the support unit 14 fixed horizontal axis of rotation.
  • the measuring carriage 132 thus follows all movements of the support unit 14 with the exception of pivoting about the body-fixed axis of rotation 70.
  • the resulting position difference between see the support unit 14 and the measuring carriage 132 can be used to generate a measurement signal, which is the size of the pivoting of the support unit 14 corresponds to the body-fixed axis 70.
  • the measuring carriage 132 can be set up to measure a rate of change of this swivel angle, ie an angular velocity of the support unit 14 with respect to the body-fixed axis of rotation 70.
  • a horizontal linear bearing 134 is formed between the measuring carriage 132 and the carrying unit 14 (see FIG. 9e).
  • the horizontal linear bearing 134 restricts the movement of the measuring carriage relative to the support unit 14 to displacements (translations) in a tangential direction of the body-fixed rotation axis 70.
  • the horizontal linear bearing 134 may be configured as a magnetically biased air bearing be.
  • the horizontal linear bearing 134 has two horizontal air bearing surfaces 136 and two vertical air bearing surfaces 138.
  • the measuring carriage 132 further has one or more first magnets 140 for generating a vertical magnetic field and one or more second magnets 142 for generating a horizontal magnetic field.
  • a horizontal air bearing surface 136 and a vertical air bearing surface 138 are arranged in the form of an "L”.
  • the first magnets 140 and the second magnets 142 are also arranged in the form of an "L”.
  • air cushions can be generated. The air cushions make it possible to displace the measuring carriage 132 in a friction-free manner in the abovementioned body-fixed tangential direction relative to the carrying unit 14.
  • the first magnets 140 and the second magnets 142 hold the measuring carriage 132 on the support unit.
  • the measuring carriage 132 is mounted on a rail 133 of the carrying unit 14 (see FIG. 10).
  • the rail 133 extends in this example along a horizontal edge 144 of the support unit 14.
  • the horizontal edge 144 of the support unit 14 itself serves as a rail (see Figures 9a and 9c).
  • the rail 133 is fixed with respect to the support unit 14.
  • Horizontal here means "body-fixed horizontal", ie perpendicular to the body-fixed axis of rotation 70.
  • the horizontal air bearing surfaces 136 and the first magnets 140 are facing a horizontal surface of the rail 133.
  • the vertical air bearing surfaces 138 and the second magnets 142 face a vertical surface of the rail 133.
  • the rail 133 and the complementary to the rail 133 each extend in the body-fixed tangential direction.
  • This straight-line design is technically particularly simple and at least applicable when the pivoting range of the support unit 14 about the body-fixed axis of rotation 70 is small, for example, less than ten degrees or less than five degrees.
  • the measuring carriage 132 extends along a circular arc with respect to the body-fixed axis of rotation 70.
  • the measuring carriage 132 is also coupled to the base unit 12 via a ball joint 146 (see in particular FIG. 4).
  • the ball joint 146 For each orientation of the body-fixed axis of rotation 70 relative to the vertical axis 68, the ball joint 146 binds the measuring carriages 132 the base unit 12 and thereby prevents the measuring carriage 132 moves with the support unit 14 when the support unit 14 is pivoted about the body fixed axis of rotation 70.
  • the ball joint 146 is arranged on a horizontal axis of rotation, namely on a horizontal axis through the vertical axis 68. Also, the ball joint 146 may be formed as an air bearing.
  • the ball joint 146 does not couple the measuring carriage 132 directly to the basic unit 12, but instead to a coupling body 148, which in turn is mounted on the base unit 12 via a two-dimensional linear bearing 150.
  • the linear bearing 150 takes into account the vertical translational freedom of the support unit 14 relative to the base unit 12.
  • the linear bearing 150 allows the measuring carriage 132 and the coupling body 148 to move vertically relative to the base unit 12 when the carrying unit 14 is displaced vertically.
  • the coupling body 148 thus follows vertical displacements (that is, translations of the support unit 14 parallel to the vertical axis 68).
  • the measuring carriage 132 in turn follows this vertical displacement of the coupling body 148 as well as all pivoting of the support unit 14 with the exception of pivoting about the body-fixed vertical axis of rotation 70th
  • the linear bearing 150 is designed as a magnetically biased air bearing. Between the coupling body 148 and a fixing body 154, an air cushion can be generated.
  • the fixing body 154 is fixed to the base unit 12.
  • the fastening body 154 is here designed as a rigid column connected rigidly to the base unit 12.
  • a mechanism is further provided which, in dependence on the described tangential displacement of the measuring carriage 132 relative to the carrying unit 14, generates a measuring signal which corresponds to the size of this displacement.
  • the measuring carriage 132 has a first scale.
  • the carrying unit 14 has a second scale.
  • the two scales each have a punctiform division. Within an overlapping area, the first and second scales overlap each other.
  • the first and the second scale shift correspondingly against each other. This changes the intensity of light that is reflected or transmitted by the two graduations.
  • the electrical measurement signal thus makes it possible to infer the magnitude of the pivoting of the support unit 14 relative to the base unit 12 about the body-fixed vertical axis of rotation 70.
  • the measurement signal can be used in particular as a feedback signal for controlling a pivoting movement of the support unit 14 about the body-fixed vertical axis of rotation 70.
  • an electronic control unit can be provided which evaluates the measurement signal and drives the motors 80, 82 suitably.
  • magnetic Strichottien can be used.
  • the measuring device 130 in FIGS. 4 and 9 to 13 is applicable in a slightly modified form to the positioning device 10 in FIGS. 1, 2 and 3 in order to measure pivoting of the carrying unit 14 relative to the base unit 12 about the body-fixed axis of rotation 70.
  • a horizontal air bearing (not shown) may be disposed between the mounting body 154 and the base plate 12 to allow the measuring carriage 132, the coupling body 148, and the mounting body 154 to move with the support unit 14 when relative to the support body Base unit 12 is moved horizontally.
  • a further rail (not shown) may be provided which extends parallel to the rail 32 (see Figures 1 to 3) and serves to guide the mounting body 154 parallel to the rail 32 when the support unit 14 is displaced along the rail becomes.
  • the ball joint 146 has a spherically convex surface 149 (see FIG. 11). This surface 149 adjoins a spherically concave surface 151 of the measuring carriage 132 complementary to it (see FIG. 8c and FIG. 8e). An air cushion can be generated between the two mutually complementary surfaces 149 and 151.
  • the ball joint 146 further includes four magnets 147 biasing the spherical bearing.
  • the ball joint 146 also has four pins for preventing rotation (not visible), which restrict the pivoting range of the ball joint 146.
  • the positioning device 10 shown in FIGS. 14 to 16 contains, in particular, the arrangement shown in FIGS. 1 to 3 with a base unit 12 and a carrying unit 14 coupled thereto.
  • the base unit 12 is displaceably mounted on a base unit 160 in the x direction.
  • the base unit 160 is formed by a substantially block-shaped block or pedestal 172, which may be made of granite or other durable material, for example.
  • the base unit 160 has a rail 162 extending in the x-direction.
  • the rail 162 serves to guide the base unit 12 in the x direction.
  • the base unit 12 is supported on side surfaces of the rail 162 via one or more air bearings 166.
  • the base unit 12 is also mounted on the base 172 via one or more horizontal air bearings 164.
  • the base unit 160 further has a first linear motor 168 and a second linear motor 170, via which the base unit 12 can be driven in the x-direction.
  • the motors 168, 170, the rail 162 and the manner of mounting the base unit 12 on and on the base unit 160 is analogous to the motors 52, 54, the rail 32 and the type of mounting of the support unit 14 on and on the base unit 12th
  • the features described with reference to FIGS. 1 to 3 can thus be transferred from the base unit 12 and the carrying unit 14 to the base unit 160 and the base unit 12.
  • the support unit 14 is omitted to show the lifting units 18, 20, 22.
  • the positioning device 10 is further provided with a measuring device 130 and a measuring device 130 'of the same type (see FIG. 16).
  • the two measuring devices 130 and 130 ' are constructed substantially like the measuring device 130 explained with reference to FIGS. 4 and 9 to 13.
  • the measuring carriage 132 is accordingly mounted on the support unit 14 via a one-dimensional linear bearing.
  • the measuring carriage 132 is coupled to the base unit 12 via a ball joint 146 and a two-dimensional linear bearing.
  • the two-dimensional linear bearing is formed between the ball joint 146 and the pillar 154.
  • the measuring carriage 132 follows pivoting of the carrying unit 14 relative to the base unit 12.
  • the measuring carriage 132 does not follow this translation movement, since it passes over the ball joint 146 and the pillar 154 is fixed to the base unit 12 in view of this degree of freedom.
  • the resulting displacement between the support unit 14 and the measuring carriage 132 is used to generate a measurement signal.
  • the two measuring devices 130 and 130 ' are arranged at different locations of the carrying unit 14. Each of the two measuring devices 130 and 130 'respectively measures a local displacement of the carrying unit 14 relative to the base unit 12.
  • the two measuring signals are transmitted to an electronic evaluation device.
  • the evaluation device determines from the two signals a displacement of the support unit 14 as a whole (for example, the displacement in the y direction of the center of gravity of the support unit 14) and the angle of pivoting of the support unit 14 a vertical axis (here the z-axis).
  • a displacement of the support unit 14 as a whole for example, the displacement in the y direction of the center of gravity of the support unit 14
  • the angle of pivoting of the support unit 14 a vertical axis (here the z-axis).
  • the maximum possible pivoting is so small that, in this connection, it is not necessary to distinguish between pivoting about a z-axis fastened to the base unit 12 and a z-axis fastened to the support unit 14.
  • the base unit 160, the base unit 12, and the support unit 14 together form a cross table.
  • the illustrated positioning device 10 offers the additional degrees of freedom: three degrees of freedom associated with the lifting units 18, 20, 22 (two pivots and translation in the z direction) and a rotational degree of freedom associated with the two motors 52, 54 (minor Pivoting of the support unit 14 about the body-fixed vertical axis of rotation 70).

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Power Engineering (AREA)
  • Container, Conveyance, Adherence, Positioning, Of Wafer (AREA)

Abstract

L'invention concerne un dispositif de positionnement (10) comprenant une unité de base (12) et une unité support (14), l'unité support (14) étant logée dans ou sur l'unité de base (12), étant mobile horizontalement par rapport à l'unité de base (12) et étant conçue pour porter un objet à positionner. Il est prévu qu'une ou plusieurs unités de levage (18, 20, 22) sont disposées entre l'unité de base (12) et l'unité support (14), chacune s'étendant de l'unité de base (12) à l'unité support (14). Chaque unité de levage (18, 20, 22) peut être commandée de telle sorte qu'un écart vertical affecté à l'unité de levage correspondante (18, 20, 22), entre l'unité de base (12) et l'unité support (14), peut être commandé de telle sorte qu'un pivotement de l'unité support (14) autour d'un axe horizontal, par rapport à l'unité de base (12), peut être commandé. Les unités de levage (18, 20, 22) peuvent respectivement comporter un piston (86) rétractable et déployable. L'invention concerne également une table à mouvements croisés comportant un tel dispositif de positionnement.
PCT/EP2012/075156 2012-12-12 2012-12-12 Dispositif de positionnement, table à mouvements croisés et unité de levage WO2014090289A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/EP2012/075156 WO2014090289A1 (fr) 2012-12-12 2012-12-12 Dispositif de positionnement, table à mouvements croisés et unité de levage

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2012/075156 WO2014090289A1 (fr) 2012-12-12 2012-12-12 Dispositif de positionnement, table à mouvements croisés et unité de levage

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WO2014090289A1 true WO2014090289A1 (fr) 2014-06-19

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6471640A (en) * 1987-09-14 1989-03-16 Matsushita Electric Ind Co Ltd One-stage six-degree of freedom accurate positioning table
DE3829022A1 (de) * 1987-08-26 1989-03-16 Toshiba Kawasaki Kk Tischverstellvorrichtung

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3829022A1 (de) * 1987-08-26 1989-03-16 Toshiba Kawasaki Kk Tischverstellvorrichtung
JPS6471640A (en) * 1987-09-14 1989-03-16 Matsushita Electric Ind Co Ltd One-stage six-degree of freedom accurate positioning table

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