JP2005195606A - X-y stage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the performance without setting accuracy of production so high, and to enable a rotation control around Z-axis with increased accuracy. <P>SOLUTION: This X-Y stage device includes a guide rail 110 having a Y-axial first guide face 110A at one side, an Y-slider 120 having an X-axial second guide face 120A, and an X-slider 130. The Y-slider 120 is formed by superposing a Y-slider body 220 having the second guide surface 120A on an elastic hinge plate 200 forming a parallel link mechanism, and constrained to be movable in Y direction on the first guide face 110A by a first link 201 of the elastic hinge plate 200. A second link 202 is arranged as a free end, and the first link 201 and the second link 202 of the Y-slider 120 are independently position-controlled by first and second Y-axial linear motors 141 and 142 and first and second Y-axial linear encoders 143 and 144, whereby the rotation θz around Z-axis of the Y-slider body 220 is actively controlled. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a stage apparatus having a slider movable in a specific direction.

  FIG. 9 shows an example of a conventional XY stage apparatus, that is, a stage apparatus having two sliders each movable in the X direction and the Y direction.

  In the figure, two guide rails 2 are fixed to the upper surface of the base 1 in parallel with each other. Here, when the two orthogonal directions are the X-axis direction and the Y-axis direction, the guide rails 2 are arranged in parallel to the Y-axis direction, and each guide rail 2 has a movable portion at both ends of the Y slider 3. 3A is fitted along the guide rail 2 so as to be slidable in the Y-axis direction. An X slider 4 is fitted to the Y slider 3 so as to be slidable in the X axis direction.

  Each guide rail 2 has a rectangular cross section, and its four peripheral side surfaces are guide surfaces parallel to the Y-axis direction. Then, the four inner surfaces of the movable portion 3A having a rectangular tube shape of the Y slider 3 face each guide surface, and an air bearing (static pressure air bearing) is disposed between the facing surfaces. Similarly, the guide portion 3B of the Y slider 3 has a rectangular cross section, and its four peripheral side surfaces are guide surfaces parallel to the X-axis direction. The four inner surfaces of the rectangular cylindrical X slider 4 are opposed to each guide surface, and an air bearing is disposed between the opposed surfaces.

  Thus, the Y slider 3 is movable in the Y axis direction with respect to the guide rail 2, and the X slider 4 is movable in the X axis direction with respect to the Y slider 3, so that the X slider 4 is in the XY plane. It can be moved to any position.

  FIG. 10 shows an example of another conventional XY stage apparatus described in Japanese Patent Laid-Open No. 2000-155186 (Patent Document 1).

  The fixed part of the XY stage apparatus is a base 11 having an upper surface as an air bearing guide surface 11A, and two guide rails 12 fixed in parallel to each other on the upper surface of the base 11.

  Here, when the three-axis directions orthogonal to each other are the X-axis, Y-axis, and Z-axis directions, and the plane including the X-axis and the Y-axis (the plane orthogonal to the Z-axis) is the XY plane, the top surface of the base 1 The hydrostatic air bearing guide surface 1A is disposed on the XY plane. The pair of guide rails 12 are arranged in the Y-axis direction, and a first guide surface 12A parallel to the Y-axis direction (perpendicular to the X-axis) is provided on the opposite side surface of each guide rail 12. .

  The portions that are linearly guided in the Y-axis direction along the opposing pair of first guide surfaces 12A are a Y slider 13 having T-shaped portions at both ends, and a T-shaped portion of the Y slider 13 via a joint 14. These are four air bearings 15 for guides provided on the side surfaces and three air bearings 16 for lift provided on the lower surface of the Y slider 13.

  In addition, a portion that is linearly guided in the Y-axis direction while being linearly guided in the Y-axis direction is an X slider 17 combined with the Y slider 13 and a joint 18 having one degree of freedom of rotation around the Z axis. These are four air bearings 19 for guides provided on the slider 17 and an air bearing 20 for lift provided on the lower surface of the X slider 17.

  With the above configuration, the Y slider 13 receives the constraint in the X-axis direction with respect to the guide rail 11 in a non-contact manner by the guide air bearing 15. Further, the Y slider 13 receives the restraint in the Z-axis direction with respect to the base 11 in a non-contact manner by the flying force of the lift air bearing 16 and the weight of the Y slider 13. Accordingly, the Y slider 13 can move (straight guide) only in the Y-axis direction due to the restriction in these two directions.

  Similarly, the X slider 17 receives the Y-axis direction constraint on the Y slider 13 in a non-contact manner by a guide air bearing 19. In addition, the X slider 17 receives the restraint in the Z-axis direction with respect to the base 11 in a non-contact manner due to the flying force of the lift air bearing 20 and the weight of the X slider. Accordingly, the X slider 17 can move (linearly guide) only in the X-axis direction with respect to the Y slider 13 by the restriction in these two directions.

  As described above, in the above-described XY stage apparatus, for example, the work placed on the X sliders 4 and 17 can be driven and controlled in the X-axis direction and the Y-axis direction. In addition to axial drive control, it may be desired to control the rotation θz about the Z axis within a slight angular range. For example, when the workpiece is placed out of alignment with the XY coordinates, the XY coordinate side can be corrected in accordance with the workpiece without replacing the workpiece.

  In such a case, conventionally, a θ table 30 as shown in FIG. 11 is separately prepared and attached on the X sliders 4 and 17. The θ table 30 is configured such that the rotation table 32 is rotatably held in the direction of arrow N with respect to the base plate 31, and the rotation table 32 can be controlled to rotate by driving the actuator 33. Is.

JP 2000-155186 A

  By the way, in the conventional stage apparatus mentioned above, the two guide rails 2 and 12 of a specific direction (Y-axis direction in the said example) are provided, and the Y slider 3 and the guide surface formed in each guide rail 2 and 12 are provided. 13 linear motions in the Y-axis direction are guided. That is, the both side support system is adopted.

  As a result, in the case of the XY stage apparatus of FIG. 9, guide surfaces are formed on both side surfaces orthogonal to the X-axis direction of the two guide rails 2 having a rectangular cross section, and the positions in the X-axis direction are formed by these guide surfaces. The linear motion of the Y slider 3 in the Y-axis direction is guided while restraining. Accordingly, four guide surfaces are involved in restraining the position of the Y slider 3 in the X-axis direction.

  Further, in the case of the XY stage apparatus of FIG. 10, the first guide surface 12A is formed on the opposite side surfaces of the two guide rails 12, and the position in the X-axis direction is constrained by the opposed first guide surfaces 12A. However, the linear motion of the Y slider 13 in the Y-axis direction is guided. Therefore, two guide surfaces are involved in restraining the position of the Y slider 3 in the X-axis direction.

  However, if the two guide rails 2 and 12 are used and a guide surface for an air bearing that requires high surface accuracy and flatness is provided on the two guide rails 2 and 12, the processing cost increases. Further, when assembling the two guide rails 2 and 12, since high accuracy is required for the parallelism of the two guide rails 2 and 12, the assembling cost is also increased. Therefore, in order to suppress the rotation θz around the Z axis of the Y sliders 3 and 13, high manufacturing accuracy is required as a whole including the positioning accuracy of the drive system, which causes an increase in manufacturing cost. Further, when there are two guide rails 2 and 12, there is a problem in that the mass of the movable part is inevitably increased due to the increase in the number of guide portions and the responsiveness is lowered. On the other hand, if the driving force is increased in order to suppress a decrease in responsiveness, there is a new possibility that an overshoot problem will occur.

  In the above description, in order to facilitate understanding, the XY stage which is the most general application example is taken as an example. However, these problems include, for example, only one slider corresponding to the Y slider. This is a problem that may occur in the same manner in a stage apparatus (a stage apparatus having only one slider that moves along a single axis).

  In view of the above circumstances, the present invention can move and position the slider with good responsiveness and accuracy along only the axis to be moved without setting the manufacturing accuracy so high. An object is to provide a cost stage device.

  A guide rail having a guide surface parallel to the Y-axis direction when two axes perpendicular to each other are defined as an X-axis direction and a Y-axis direction, and a plane including the X-axis and the Y-axis is an XY plane; One end of which is supported so as to be movable along the guide surface, and the other end is a free end that extends in the X-axis direction. The Y-slider extends along the Y-axis direction. A parallel link mechanism comprising a pair of first and second links parallel to each other and a connecting link for connecting the first and second links, and one of the first and second links being included. The link is disposed on one end side of the Y slider, and is supported so as to be movable along the guide surface of the guide rail.

  In the present invention, the guide rail is squeezed only on one side, the Y slider is supported on the guide rail in a cantilevered manner, and the positioning of the Y slider in the X-axis direction is only on one end side (one end side), and the other end side is basically The guide is free.

  Therefore, simplification of the structure can be realized by the guide rail being narrowed to one side. In addition, since the guide rail exists only on one side, it is not necessary to assemble while ensuring mutual parallelism, and the number of bearings can be reduced, resulting in manufacturing costs including processing costs and assembly costs. Overall reduction can be achieved. Furthermore, since the guide rail has a guide system only on one side, the mass of the movable part is reduced, and the same drive power increases the response.

  In addition, since the parallel link mechanism having the first and second links along the Y-axis direction is adopted, for example, the first link on one end side and the second link on the other end side are independently Y by two driving means. When driven in the axial direction, the first and second links can be translated. That is, both the first and second links can be displaced in parallel without being inclined with respect to the Y-axis direction.

  Therefore, regardless of whether the other end side of the Y slider is a free end, the Y slider can be driven while keeping one end side and the other end side parallel to the Y-axis direction.

  The present invention further includes first Y-axis driving means for driving one end side of the Y slider in the Y-axis direction, and second Y-axis driving means for driving the other end side of the Y slider in the Y-axis direction. Is preferred.

  With this configuration, θz can be positively controlled to an arbitrary value (at least in a minute range such as correction of the coordinate system), and the Y slider can be slightly rotated. In other words, this rotation (hereinafter referred to as this rotation in this specification) is configured such that the other end side of the Y slider is a free end and driven by the first Y-axis driving means and the second Y-axis driving means in the Y-axis direction. Can be realized without intentionally providing a dedicated drive actuator in the θz direction, and the cost for that is eliminated. Further, since it is not necessary to attach the θ table, it is possible to reduce the overall weight and to minimize the decrease in acceleration / deceleration performance.

  In this configuration, as long as the positioning accuracy of the first and second Y-axis driving means for positioning both ends of the Y slide is ensured, a corresponding precision can be ensured only by the open command to the driving means.

  However, on the other hand, in this configuration, the accuracy of the entire apparatus (especially the accuracy around the Z axis) is dependent on the accuracy of the first and second Y-axis drive means themselves. High precision (high cost) must be adopted as the Y axis drive means.

  Therefore, a first position detecting means for detecting a position in the Y-axis direction on one end side of the Y slider, a second position detecting means for detecting a position in the Y-axis direction on the other end side of the Y slider, and the first And a control means for controlling the first and second Y-axis drive means based on the detection signals of the first and second position detection means. One end side (guide end side) and the other end side (free end side) of the slider can be driven while being positioned independently.

  That is, according to this configuration, the position on the guide end side (one end side) of the Y slider is detected by the first position detecting means, and the position on the free end side (the other end side) is detected by the second position detecting means. . Based on both detection results, the movement in the Y-axis direction on the guide end side and the movement in the Y-axis direction on the free end side are synchronized. Accordingly, the rotation θz around the Z axis of the Y slider can be freely controlled. For example, if the guide end side is driven to a predetermined required position and feedback control is performed based on the position detection signal so that the free end side becomes θz = 0, the Y-axis direction can be achieved while being a cantilever type guide. The position accuracy can be increased more easily than before.

  In other words, the position accuracy in the Y-axis direction or the accuracy in the θz direction of the Y slider can be obtained by a combination of the position detection means and the drive means without depending on the performance of the guide part. Only the positioning function of the Y slider in the X-axis direction can be expected.

  As a result, it is possible to achieve both simplification of the structure, low cost, and high accuracy.

  Also, the second link of the parallel link mechanism is always displaced parallel to the Y-axis direction regardless of the magnitude of the change in the rotation θz around the Z-axis. When the position of the two links is detected by the second position detecting means, detection abnormality is less likely to occur, and good detection can always be performed, and the accuracy of θz control based on the detection can be improved.

  Further, the present invention is configured such that the connection link is a pair of third and fourth links parallel to each other and is connected to the first and second links to form a parallelogram parallel link mechanism. You can also According to this configuration, the parallel link mechanism has the first and second links along the Y-axis direction and the third and fourth links along the X-axis direction. By supporting (restraining) the first link located along the first guide surface of the guide rail so as to be movable, the other three links can be freely displaced while maintaining the parallelness of the links facing each other. Can do.

  Moreover, this invention can also be set as the structure by which the said parallel link mechanism is connected by the elastic hinge which can bend and deform | transform each link in XY plane.

  According to this configuration, since the elastic hinge is used as the connecting hinge of the parallel link mechanism, high-precision positioning performance without backlash can be obtained. Further, since the elastic hinge always has the property of returning to the original position, the convergence (stability) of the control system can be kept high.

  In the present invention, it is preferable that the first Y-axis driving unit and the second Y-axis driving unit are constituted by linear motors that transmit driving force to one end side and the other end side of the Y slider in a non-contact manner.

  According to this configuration, since the Y slider is driven in a non-contact manner by the linear motor, it is optimal in that the movement of the free end side of the Y slider can be allowed, and the responsiveness can be improved. Moreover, since there is no contact, there is no rolling fatigue and positioning accuracy can be increased.

  As described above, according to the present invention, since the guide rail is a cantilever type guide that is squeezed only to one side, it is not necessary to assemble the guide rail while ensuring mutual parallelism as in the conventional example. As a result, the number of parts such as bearings can be reduced, and as a result, the overall manufacturing cost including the processing cost and the assembling cost can be reduced and the maintainability can be improved. In addition, since the guide rail is only on one side and the number of guide parts is reduced, there is an advantage that the mass of the movable part is reduced and the responsiveness is increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a plan view showing a state in which a stage apparatus according to an embodiment of the present invention is applied to a portion related to driving of a Y slider of an XY stage apparatus, FIG. 2 is a view taken in the direction of arrow II in FIG. FIG. 3 is a view taken in the direction of arrow III in FIG. 1. FIG. 4 is an enlarged schematic perspective view of a portion IV in FIG.

  As shown in FIGS. 1 to 3, the XY stage apparatus includes a base 101 and three rectangular slide bases 102 and 103 made of a magnetic material arranged in a river shape on the base 101. 104, one magnetic guide rail 110 fixed on the slide base 102 located at the end, and a plan view T in which one end is constrained to the guide rail 110 and the other end extends as a free end. A character-shaped Y slider 120 and an X slider 130 assembled to the Y slider 120 are provided.

  When the three axis directions orthogonal to each other are the X-axis, Y-axis, and Z-axis directions, and the plane including the X-axis and the Y-axis is the XY plane, the slide bases 102, 103, and 104 are on the XY plane. The upper surfaces of the slide bases 102, 103, 104 are reference guide surfaces (third guide surface and fourth guide surface) 105 that are orthogonal to the Z-axis direction. The slide bases 102, 103, and 104 are arranged in the X-axis direction in this order with the longitudinal direction along the Y-axis direction.

  The guide rail 110 is fixed along the Y-axis direction on the slide base 102 located at one end of the slide bases 102, 103, and 104. As shown in FIG. 4, a first guide surface 110A parallel to the Y-axis direction (perpendicular to the X-axis direction) is formed on the inner side surface of the guide rail 110 (the side surface facing the center side of the base 101). Has been.

  The T-shaped Y slider 120 includes a head portion 121 extending in the Y-axis direction along the guide rail 110 and a linear guide portion 122 extending in the X-axis direction from the middle in the length direction of the head portion 121. . The linear guide portion 122 extends in the X-axis direction so as to cross the central slide base 103, and as shown in FIG. 3, on the elastic hinge plate 200 disposed on the lower surface side, the Y slider body. It has a two-stage structure in which 220 are stacked.

  5A and 5B are plan views of the elastic hinge plate 200, where FIG. 5A shows a state before deformation, and FIG. 5B shows a deformed state.

  As shown in FIG. 5, the elastic hinge plate 200 includes a pair of first and second links 201 and 202 parallel to each other along the Y-axis direction and the other parallel to each other along the X-axis direction. Parallel four sides that are connected by elastic hinges (connection hinges) 205, 206, 207, and 208, in which a pair of third and fourth links 203 and 204 are arranged, and the adjacent links can be rotated only in the XY plane It is configured as a parallel link mechanism.

  In addition, an intermediate link 209 is arranged in the middle of the first link 201 and the second link 202 in parallel with the first link 201 and the second link 202, and both ends of the intermediate link 209 are connected to the third link 203. The fourth link 204 is connected to an intermediate portion in the length direction via elastic hinges 210 and 211.

  The elastic hinges 205 to 208, 210, and 211 are provided with the bending deformation directions all aligned in the X-axis direction. In this case, the elastic hinge plate 200 includes five links 201 to 204, 209 and six bridge-shaped elastic hinges 205 to 208, 210, 211 connecting the links to a single metal plate (not necessarily thin). Are integrally formed on the outer side of the first link 201 and the outer side of the second link 202. In addition, one of the two links 203 and 204 along the Y-axis direction is provided with a bolt hole 212 for coupling the Y slider body 220 to one of the third links 203.

  As shown in FIG. 1, the first link 201 of the elastic hinge plate 200 is coupled to the head portion 121 by the mounting bracket 214, and the second link 202 is disposed as a free end on the other end side of the Y slider 120. .

  On the elastic hinge plate 200, a rectangular plate-shaped Y-slider body 220 having substantially the same size is placed. The Y slider main body 220 and the elastic hinge plate 200 are coupled to each other only by the third link 203, and the other portions can slide relative to each other. That is, the Y slider body 220 and the elastic hinge plate 200 are coupled by screwing the bolt 221 passed through the Y slider body 220 into the bolt hole 212 of the third link 203. Therefore, the elastic hinge plate 200 can be freely deformed on the lower surface side of the Y slider body 200.

  A second guide surface 120A parallel to the X-axis direction (perpendicular to the Y-axis direction) is formed on one side surface of the Y slider main body 220 on the third link 203 side.

  As shown in an enlarged view in FIG. 4, a lift air bearing 123 and a lift preload magnet 124 are arranged on the bottom surface of the head portion 121 coupled to the first link 201 located on one end side of the Y slider 120. A guide air bearing 125 and a guide preload magnet 126 are disposed on the side surface of the rail 110 that faces the first guide surface 110A. Further, as shown in FIG. 1, a lift air bearing 127 and a lift preload magnet 128 are disposed on the bottom surface of the second link 202 and the mounting bracket 215 located on the other end side of the Y slider 120.

  Three lift air bearings (lift gas bearings) 123, 123, 127 are for supporting the Y slider 120 so as to be movable in the XY plane, and the reference guide surfaces 105 of the slide bases 102, 104. By blowing air (other gas may be used) to the Y slider 120, a flying force is applied to the Y slider 120. Lift preload magnets (magnetic force generating means) 124, 124, 128 arranged in the vicinity of the lift air bearings 123, 123, 127 are made of permanent magnets, and the levitation force is generated between the reference guide surface 105 and the Y slider 120. A magnetic attractive force is generated as a preload to counteract.

  Therefore, the Y slider 120 is supported on the reference guide surface 105 at a predetermined height in a non-contact manner by the levitation force and the magnetic attraction force due to the air bearing action. That is, the magnetic attractive force by the lift preload magnets 124 and 128 decreases as the distance between the Y slider 120 and the reference guide surface 105 increases, and the levitation force due to the air blowing from the lift air bearings 123 and 127 decreases as the distance increases. . In addition, since the magnetic attraction force and the levitation force are opposite forces, the Y slider 120 is supported movably at a height (levitation gap = gap) in which both are balanced.

  The guide air bearing (guide gas bearing) 125 and the guide preload magnet (magnetic force generating means) 126 are arranged so that the head 121 on one end side of the Y slider 120 moves along the first guide surface 110A of the guide rail 110 along the Y axis. The guide air bearing 125 blows air toward the first guide surface 110A of the guide rail 110, thereby supporting the Y slider 120. A guide preload magnet 126 made of a permanent magnet is applied as a preload that counteracts the levitation force between the first guide surface 110A of the guide rail 110 and the head portion 121 of the Y slider 120. Generates attractive force and balances levitation force and magnetic attraction force based on the same principle as above More, the Y slider 120 is floated by a predetermined amount from the first guide surface 110A of the guide rail 110 for guiding in a non-contact state.

  The lift air bearing 123, the lift preload magnet 124, the guide air bearing 125, and the guide preload magnet 126 are each provided in pairs, and the center line in the length direction of the head portion 121 of the Y slider 120 (the linear guide portion 122). (Which is also the center line in the width direction).

  In this case, the lift air bearing 123 is disposed on the outermost side, the lift preload magnet 124 and the guide preload magnet 126 are disposed on the inner side, and the guide air bearing 125 is disposed further on the inner side.

  That is, the distance between the paired lift air bearings 123 and 123 is set to be as large as possible. This is because if the distance between the lift air bearings 123 and 123 is increased, the rotation θx around the X axis of the Y slider 120 can be suppressed (the rigidity in the θx direction can be increased).

  Note that the lift air bearings 123 and 127 and the guide air bearing 125 that generate air by blowing air are connected to the Y slider 120 via a spherical joint 129, as shown in FIG.

  With such a configuration, the Y slider 120 is movable only in the Y-axis direction while floating on the slide bases 102 to 104. As shown in FIG. 1, a first Y-axis linear motor (first Y-axis drive unit) that drives one end side of the Y slider 120 in the Y-axis direction independently of the one end side and the other end side of the Y slider 120. 141, and a second Y-axis linear motor (second Y-axis drive means) 142 that drives the other end side in the Y-axis direction. The linear motors 141 and 142 can transmit driving force to the Y slider 120 in a non-contact manner with the base 101 side.

  Further, on one end side and the other end side of the Y slider 120, a first Y axis linear encoder (first position detecting means) 143 for detecting a position in the Y axis direction on one end side of the Y slider 120, and the Y slider 120, respectively. A second Y-axis linear encoder (second position detecting means) 144 that detects the position of the other end side in the Y-axis direction is provided, and a control means (not shown) is based on the detection signals of these linear encoders 143 and 144. The first Y-axis linear motor 141 and the second Y-axis linear motor 142 are controlled.

  The first Y-axis linear motor 141 is provided so as to drive the first link 201 (actually the head unit 121 coupled to the first link 201) of the elastic hinge plate 200 constituting the Y slider 120, and the second Y-axis The linear motor 142 is provided so as to drive the second link 202 (actually a member coupled to the second link 202) of the elastic hinge plate 200 constituting the Y slider 120.

  Similarly, the first Y-axis linear encoder 143 detects the position in the Y-axis direction of the first link 201 (actually the head unit 121 coupled to the first link 201) of the elastic hinge plate 200 constituting the Y slider 120. The second Y-axis linear encoder 144 determines the position in the Y-axis direction of the second link 202 (actually a member coupled to the second link 202) of the elastic hinge plate 200 constituting the Y slider 120. It is provided to detect.

  On the other hand, as shown in FIG. 3, the X slider 130 is formed in an inverted L-shaped cross section having a side wall 131 and an upper wall 132, and is placed on the linear guide portion 122 of the Y slider 120. The side wall 131 of the X slider 130 is at a position facing the second guide surface 120A of the Y slider main body 220, and the inner surface of the side wall 131 faces the second guide surface 120A and two guide air bearings 133 and One guide preload magnet 134 is disposed between them. Further, three lift air bearings 135 are arranged on the X slider 130. The three lift air bearings 135 are arranged at positions that can support the X slider 130 in a well-balanced manner at positions that do not interfere with the Y slider 120. The guide air bearing 133 and the lift air bearing 135 are connected to the X slider 130 via spherical joints 136 and 137.

  Three lift air bearings (lift gas bearings) 135 support the X slider 130 so as to be movable in the XY plane, and blow out air to the reference guide surface 105 of the slide base 103. As a result, a flying force is applied to the X slider 130. Then, the X slider 130 is supported on the reference guide surface 105 at a predetermined height in a non-contact state by a balance between the flying force due to the air bearing action and the own weight of the X slider 130.

  A guide air bearing (guide gas bearing) 133 and a guide preload magnet (magnetic force generating means) 134 support the X slider 130 movably in the X axis direction along the second guide surface 120A of the Y slider 120. However, the guide air bearing 133 blows air to the second guide surface 120A of the Y slider 120, thereby causing the X slider 130 to move against the second guide surface 120A. A guide preload magnet 134 that applies a levitating force (separation force) and is made of a permanent magnet has a magnetic attractive force as a preload that opposes the levitating force between the second guide surface 120A of the Y slider 120 and the side wall 131 of the X slider 130. The second draft of the Y slider 120 is generated by the balance between the levitation force and the magnetic attraction force. The X slider 130 from the surface 120A is floated by a predetermined amount to guide a non-contact state.

  With such a configuration, the X slider 130 is guided by the Y slider main body 220 while being floated on the slide base 103 and is movable only in the X-axis direction. As shown in FIG. 3, the X slider 130 is driven in the X axis direction by an X axis linear motor 151 installed on the upper surface of the Y slider body 220. Further, the X slider 130 is provided with an X axis linear encoder 152 that detects the position of the X slider 130 in the X axis direction, and a control means (not shown) is based on the detection signal of the X axis linear encoder 152. The X-axis linear motor 151 is controlled.

  Next, the control system will be described.

  The position control of the Y slider 120 in the Y axis direction and the position control of the X slider 130 in the X axis direction are based on the thrust of the Y axis linear motors 141 and 142 and the X axis linear motor 151, the Y axis linear encoders 143 and 144, This can be performed by feedback control based on the detection signal of the X-axis linear encoder 152.

  The position control of the X slider 130 is not particularly different from the conventional one, but the position control of the Y slider 120 has characteristics and will be described below.

  As described above, the Y slider 120 has a structure in which the rotation θz around the Z axis is likely to occur because of the structural feature that only one end (one end side) is guided by the guide rail 110. In particular, the Y-slider 120 includes an elastic hinge plate 200, which has a small angle (± 1 to 3 degrees), but the elastic hinge plate 200 can positively increase the degree of freedom of rotation (θz) about the Z axis. I try to get it.

  In the XY stage apparatus of this embodiment, one control side (first link 201 side) and the other end side (second link side) of the Y slider 120 are used as a control method for ensuring positioning accuracy and horizontal guidance accuracy. Two sets of measurement / drive systems are provided, and the Y-θ control method is adopted. Here, θ is θz.

  Details thereof will be described with reference to FIG.

If the measured value of the first Y-axis linear encoder 143 is Y1FB and the measured value of the second Y-axis linear encoder 144 is Y2FB, the feedback value YFB in the Y-axis direction is
YFB = (Y1FB + Y2FB) / 2
It becomes.

Also, considering that the rotation angle is very small, the feedback value θFB of the θ axis (θz) is
θFB = (Y1FB−Y2FB) / L
It becomes.

  Therefore, a deviation calculation is performed between the feedback values YFB and θFB and the target values Yref and θref for the Y-axis and θ-axis to calculate force command values FY and Fθ for the Y-axis and θ-axis. From these force command values, the calculation formulas of the force command values FY1, FY2 to the linear motors 141, 142 are as follows.

FY1 = FY + Fθ
FY2 = FY-Fθ

  Therefore, the Y slider 120 is controlled in the Y-θ direction by outputting the calculation result of the above equation to the motor amplifiers 147 and 148.

  Next, the operation will be described.

  In this XY stage apparatus, the fixed parts are a base 101, slide bases 102 to 104, and guide rails 110. Further, the portions that are linearly guided in the Y-axis direction are the Y slider 120, the lift air bearing 123, the guide air bearing 125, the lift preload magnet 124, and the guide preload magnet 126. Further, while being linearly guided in the Y-axis direction, the portions linearly guided in the X-axis direction are the X slider 130, the guide air bearing 133, the guide preload magnet 134, and the lift air bearing 135.

  Therefore, in this stage apparatus, when the first Y-axis linear motor 141 and the second Y-axis linear motor 142 are driven, the Y slider 120 is driven in the Y-axis direction while being restrained in the X-axis direction by the guide rail 110. At that time, due to the action of the lift air bearings 123 and 127 and the lift preload magnets 124 and 128, the Y slider 120 is in a non-contact state while ensuring a certain floating clearance with respect to the reference guide surface 105 of the slide bases 102 to 104. Guided. Further, due to the action of the guide air bearing 125 and the guide preload magnet 126, the Y slider 120 is guided in a non-contact state while ensuring a certain floating gap (gap) with respect to the first guide surface 110 </ b> A of the guide rail 110. .

  Here, in this XY stage apparatus, only one guide rail 110 is intentionally provided, and the elastic hinge plate 200 of the Y slider 120 is supported on the guide rail 110 in a cantilever manner. The positioning of the Y slider 120 in the X-axis direction is limited to one end side (one end side) and the other end side is basically guide-free.

  Therefore, the Y slider 120 obtains the degree of freedom of rotation (degree of freedom of θz) around the axis (Z axis) orthogonal to the XY plane from the features of this support structure. In this stage apparatus, the measuring / driving system is controlled so that the position of the one end side (first link 201 side) and the other end side (second link side) of the elastic hinge plate 200 of the Y slider 120 can be controlled independently. Two sets are provided. As a result, the rotation θz around the Z axis of the Y slider 120 can be freely controlled.

  For example, as described above, if the first and second Y-axis linear motors 141 and 142 are feedback-controlled based on the position detection signals of the first and second Y-axis linear encoders 143 and 144, the cantilever type guide is used. However, the positional accuracy in the Y-axis direction can be improved as compared with the conventional case.

  Further, the first and second Y-axis linear motors 141 and 142 are feedback-controlled based on the position detection signals of the first and second Y-axis linear encoders 143 and 144 by utilizing the feature of being a cantilever guide. Thus, the Y slider main body 220 on the elastic hinge plate 200 constituting the Y slider 120 can be actively controlled to rotate around the Z axis (θz control).

  That is, when a force as indicated by an arrow in FIG. 5A acts on the elastic hinge plate 200, the elastic hinges 205 to 208, 210, and 211 are bent and deformed as shown in FIG. The connected first and second links 201 and 202 are only translated without rotating, and rotational displacement (rotation θz) is obtained in the third and fourth links 203 and 204 along the other two X-axis directions. . In this case, the rotational position in the θz direction can be obtained by the following equation, assuming that the displacements in the Y-axis direction of the first and second links 201 and 202 are Y1 and Y2.

θz = sin ^-1 [(Y1-Y2) / L] where L: distance between hinges

  Here, the Y slider main body 220 and the elastic hinge plate 200 are connected only by the third link 203, and the other links 201, 202, and 204 are free. For this reason, the Y slider main body 220 rotates in the θz direction together with the third link 203.

  An arbitrary drive resolution in the θz direction can be obtained by combining the distance L between the hinges and the resolution of the first and second Y-axis linear encoders 143 and 144. In addition, since the elastic hinge plate 200 is provided with the intermediate hinge 209, it is lightweight and secures sufficient rigidity, contributing to increasing the θz rotation accuracy of the second guide surface 120A of the Y slider body 220. Yes.

  In this case, since the elastic hinge plate 200 is a parallel link mechanism, the following effects can be obtained.

  That is, as shown in FIG. 7A, when the first link 201 and the second link 202 are driven in the Y-axis direction independently by the first Y-axis linear motor 141 and the second Y-axis linear motor 142, The second links 201 and 202 translate, but since the first link 201 is constrained in a posture parallel to the Y-axis direction, the second link 202 on the free end side also moves in the Y-axis direction. It will be displaced in parallel without being inclined.

  Therefore, regardless of the magnitude of the change in the rotation θz around the Z axis, the position of the second link 202 located on the other end side of the Y slider 120 by the second link 202 being always displaced in parallel in the Y axis direction. Is detected less easily by the second Y-axis linear encoder 144.

  For example, if a light emitting unit is provided on the movable side (here, the second link 202) of the second Y-axis linear encoder 144 and a light receiving unit is provided on the fixed side, the detection light K emitted from the second link 202 on the movable side is second. It goes out perpendicular to the link 202 and reaches the light receiving part.

  At this time, in the case of the example of FIG. 7B in which the elastic hinge plate is not used, the optical axes of the light emitting side and the light receiving side shift as the displacement of θz increases (the light K reaches obliquely). , Detection errors are likely to occur.

  On the other hand, when the elastic hinge plate 200 of FIG. 7A is used, the second link 202 is displaced in parallel to the Y-axis direction as described above, so that the parallelism between the light emitting side and the light receiving side is always maintained. No detection abnormality occurs. Therefore, good detection can always be performed, and the accuracy of θz control based on the detection can be improved.

  In addition to driving the Y slider 120, when the X axis linear motor 151 is driven, the X slider 130 is driven in the X axis direction while being restrained in the Y axis direction by the Y slider body 220. At that time, the X slider 130 is guided in a non-contact state with respect to the reference guide surface 105 of the slide bases 102 to 104 while ensuring a certain floating gap by the action of the lift air bearing 135. In addition, due to the action of the guide air bearing 133 and the guide preload magnet 134, the X slider 130 is guided in a non-contact state while ensuring a certain floating gap (gap) with respect to the second guide surface 120A of the Y slider 120. .

  The X slider 130 is driven and controlled to an arbitrary position in the XY plane by drive control of the Y slider 120 in the Y axis direction and drive control of the X slider 130 in the X axis direction with respect to the Y slider 120.

  In this case, since the Y slider 120 is driven in a non-contact manner by the linear motors 141 and 142 in particular, it is optimal in that the movement of the free end side of the Y slider 120 can be allowed, and the responsiveness is also improved. it can. Moreover, since there is no contact, there is no rolling fatigue and positioning accuracy can be increased.

  In addition, in the case of this XY stage apparatus, the guide rail 110 is narrowed down to one, so that the structure is simplified and the necessary and sufficient positioning accuracy in the Y-axis direction can be obtained even if the processing accuracy is not so high. It will come out. Further, since there is only one guide rail 110, there is no need for the trouble of assembling the two guide rails while assuring the parallelism between them as in the prior art. Further, since the number of bearings can be reduced, as a result, the entire manufacturing cost including the processing cost and the assembling cost can be reduced. Moreover, since the guide rail 110 became one, the movable part mass becomes light and responsiveness increases.

  In addition, since the magnet preload system is adopted for the guide system by the guide air bearing 125 of the Y slider 120, the guide rigidity can be increased, and the flying gap (the flying height) of the Y slider 120 from the guide rail 110 can be accurately measured. It can be kept well and the positioning accuracy of the Y slider 120 in the X-axis direction can be increased.

  Further, as in the conventional example of FIG. 10, a method of positioning in the X-axis direction by stretching the Y slider against the two guide rails on both sides is not adopted, but the guide rail 110 of only one side is used. Since the Y slider 120 can be accurately positioned in the X-axis direction with only one guide surface 110A, the number of guide surfaces for guiding the Y slider 120 is minimized, and the number of air bearings is also halved. Can do. Therefore, naturally, the mass of the Y slider 120 can be reduced and the responsiveness can be improved.

  Similarly, since the magnet preload system is also adopted for the guide system using the guide air bearing 133 of the X slider 130, the rigidity of the guide system can be increased, and the floating clearance (from the Y slide 120 of the X slider 130) The flying height) can be kept constant with high accuracy, and the positioning accuracy of the X slider 130 in the Y-axis direction can be increased.

  Further, as in the conventional example of FIG. 10, in order to balance the flying force and the preload, a method is adopted in which two guide surfaces provided on both lateral surfaces of the Y slider are sandwiched between X sliders having an inverted U-shaped cross section. Instead, the X slider 130 can be accurately positioned in the Y-axis direction by using only one guide surface 120A. Therefore, the number of guide surfaces for guiding the X slider 130 is minimized, and the number of air bearings is reduced. Can also be halved. Therefore, naturally, the mass of the X slider 130 can be reduced and the responsiveness can be improved.

  Further, in this XY stage apparatus, since the bearing interval of the lift air bearing 123 provided in the head portion 121 of the Y slider 120 is set larger than the bearing interval of the guide air bearing 125, the Y around the X axis is set. This is preferable in that the rotation θx of the slider 120 is suppressed. That is, by increasing the bearing interval of the lift air bearing 123, the motion error due to the pitching motion θx of the stage can be reduced. In addition, this makes it possible to average the processing errors of the slide bases 102 to 104, and to prevent a reduction in straightness in the vertical direction.

  Further, as described above, since the rotation θz around the Z axis can be actively controlled to an arbitrary value, the XY guide system can be effectively rotated, for example, When the workpiece is placed out of alignment with the XY coordinates, the XY coordinate side can be corrected in accordance with the workpiece without replacing the workpiece.

  Further, since the drive control in the θz direction is performed by the two linear motors 141 and 142 in the Y axis direction, it is not necessary to attach another device such as the θ table in FIG. It becomes. Further, since no separate device such as a θ table is required, the overall weight can be reduced, and the reduction in acceleration / deceleration performance can be minimized.

  In addition, since it is not necessary to stack θ tables, it is possible to suppress an increase in Abbe error, and since the center of gravity does not increase, rotational vibration (pitching) around the X axis is less likely to occur, and settling during positioning is possible. You can save time.

  Since the elastic hinge plate 200 is employed as the parallel link mechanism, a highly accurate θz positioning performance without backlash can be obtained. In particular, by aligning the bending directions of the elastic hinges 205 to 208 in the X-axis direction, the bending directions of all the elastic hinges including the elastic hinges 210 and 211 at both ends of the intermediate link 209 are aligned in the X-axis direction. It becomes easy to unify the bending deformation performance in the elastic hinge, which can contribute to the improvement of accuracy in the θz control along with the ease of processing.

  The parallel link mechanism is made by combining the first to fourth links 201 to 204, the intermediate link 209, and all the elastic hinges 205 to 208, 210, and 211, all cut out from one metal plate. By forming them integrally, it is possible to improve accuracy as a parallel link mechanism and facilitate manufacture. Moreover, since it is a simple structure as one plate, weight reduction and cost reduction can be achieved.

  The structure of the elastic hinge plate is not particularly limited as long as it constitutes a parallel link mechanism. In short, the elastic hinge plate may have a pair of links parallel to each other along the Y-axis direction. good. Therefore, as in the elastic hinge plate 300 shown in FIG. 8, the bending deformation directions of the elastic hinges 305 to 308 that connect the first to fourth links 301 to 304 may be aligned in the Y-axis direction. Good. In this case, the directions of the four elastic hinges 305 to 308 are different from the directions of the elastic hinges 310 and 311 at both ends of the intermediate link 309, but there is no difference in the function as a parallel link mechanism.

  As described above, the stage apparatus according to the embodiment of the present invention has been described by showing an example in which the stage apparatus is applied to an XY stage apparatus. However, the present invention does not have an X slider (uniaxial stage apparatus having only a Y slider). Needless to say, this is applicable.

  Even if the manufacturing accuracy is not set so high, the slider can be used as a low-cost stage device that can move and position with high responsiveness and accuracy along only the axis to be moved.

The top view which applied the stage apparatus which concerns on embodiment of this invention to the XY stage apparatus II view of FIG. View along arrow III in Fig. 1 Fig. 1 is a schematic enlarged perspective view of the IV arrow portion Top view of elastic hinge plate Block diagram of drive control system of Y slider in XY stage apparatus Action explanatory diagram of elastic hinge plate Plan view showing another example of elastic hinge plate A perspective view showing an example of a conventional XY stage apparatus The perspective view which shows the example of another conventional XY stage apparatus Plan view of θ table attached to conventional XY stage device

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Base 102-104 ... Slide base 105 ... Reference | standard guide surface 110 ... Guide rail 110A ... 1st guide surface 120 ... Y slider 120A ... 2nd guide surface 121 ... Head part (one end side)
123 ... lift air bearing (gas bearing for lift)
124 ... Lift preload magnet (magnetic force generating means)
125 ... Guide air bearing (gas bearing for guide)
126 ... Guide preload magnet (magnetic force generating means)
127 ... Lift air bearing (gas bearing for lift)
128 ... Lift preload magnet (magnetic force generating means)
129: Spherical joint 130 ... X slider 133 ... Guide air bearing 134 ... Guide preload magnet 135 ... Lift air bearing 136, 137 ... Spherical joint 141 ... First Y-axis linear motor (first Y-axis drive means)
142 ... 2nd Y-axis linear motor (2nd Y-axis drive means)
143 ... 1st Y-axis linear encoder (1st Y-axis position detection means)
144 ... 2nd Y-axis linear encoder (2nd Y-axis position detection means)
DESCRIPTION OF SYMBOLS 151 ... X-axis linear motor 152 ... X-axis linear encoder 200 ... Elastic hinge plate 201 ... 1st link 202 ... 2nd link 203 ... 3rd link 204 ... 4th link 205-208 ... Elastic hinge 209 ... Intermediate links 210, 211 DESCRIPTION OF SYMBOLS ... Elastic hinge 220 ... Y slider main body 300 ... Elastic hinge plate 301 ... 1st link 302 ... 2nd link 303 ... 3rd link 304 ... 4th link 305-308 ... Elastic hinge 309 ... Intermediate link 310, 311 ... Elastic hinge

Claims (6)

When the two axis directions orthogonal to each other are the X axis direction and the Y axis direction, and the plane including the X axis and the Y axis is the XY plane,
A guide rail having a guide surface parallel to the Y-axis direction;
One end of which is supported so as to be movable along the guide surface, and the other end of the Y slider extends in the X-axis direction as a free end,
The Y slider is configured to include a parallel link mechanism including a pair of first and second links parallel to each other along the Y-axis direction and a connecting link that connects the first and second links.
One of the first and second links is arranged on one end side of the Y slider and is supported so as to be movable along the guide surface of the guide rail. Stage device. In claim 1, further comprising:
A stage apparatus comprising: a first Y-axis drive unit that drives one end side of the Y slider in the Y-axis direction; and a second Y-axis drive unit that drives the other end side of the Y slider in the Y-axis direction. . In claim 1 or 2,
First position detecting means for detecting a position in the Y-axis direction on one end side of the Y slider;
Second position detecting means for detecting a position in the Y-axis direction on the other end side of the Y slider;
Control means for controlling the first Y-axis drive means and the second Y-axis drive means based on detection signals of the first and second position detection means;
A stage apparatus characterized by comprising: In any one of Claims 1-3,
The connecting link is a pair of third and fourth links parallel to each other, and is connected to the first and second links to form a parallelogram parallel link mechanism. In any one of 1 to 4,
In the parallel link mechanism, each link is connected by an elastic hinge that can be bent and deformed in an XY plane. In claim 2,
The stage device, wherein the first Y-axis driving unit and the second Y-axis driving unit are configured by linear motors that transmit driving force to one end side and the other end side of the Y slider in a non-contact manner, respectively.

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