JP4402078B2 - Stage equipment - Google Patents

Description

  The present invention relates to a stage apparatus, and more particularly to a stage apparatus configured to cope with an increase in the distance between sliders and the movement distance associated with an increase in the size of a workpiece.

  For example, in a stage apparatus, a stage guide mechanism that guides the movement of the stage has a pair of guide parts made of stone fixed on the surface plate, and a slider of the stage that moves along the guide part includes: There is a hydrostatic bearing pad facing the guide surface of the guide part with a gap of several μ to dozens of μ, and the slider moves in a state of being lifted by the air pressure blown from the hydrostatic bearing pad to the guide surface Is configured to do.

  In such a stage apparatus, as the substrate supplied as a workpiece increases in size, the entire apparatus increases in size, and the moving distance of the stage is being extended accordingly.

  In the existing machining technique, for example, if the guide portion has a total length of about 1 m as usual, it can be processed with a processing accuracy of several μm. However, if the total length of the guide part becomes longer than 2m as the moving distance of the stage is extended, it becomes difficult to measure accurately, and measurement error when measuring the straightness over the entire length of the guide part. Therefore, it becomes difficult to manufacture a guide portion having straightness so as to clear the required accuracy, and a dimensional change due to thermal expansion affects distortion and twist of the guide portion.

  The pair of guide portions is provided with a linear scale for detecting the moving position of the stage. If a sensor (for example, a photo interrupter) attached to the stage moves along the linear scale, a detection signal (pulse signal) is provided. ) Is output. Then, the distance is calculated by counting signals from the linear scale sensor to obtain the position.

  Further, in order to maintain the straight advance accuracy of the stage and the position detection accuracy by the linear scale, it is necessary to manage the parallelism of the pair of guide portions with higher accuracy as the total length of the guide portions becomes longer.

In order to reduce the influence of such variations in straightness and parallelism of the pair of guide portions, for example, between a pair of sliders moving along the pair of guide portions and a beam connecting the pair of sliders. There is a structure in which the load on the guide portion is reduced by connecting them with a leaf spring interposed therebetween (see, for example, Patent Document 1).
JP 2000-214280 A

  However, the stage device disclosed in Patent Document 1 has a limit that can reduce the burden on the guide portion. For example, in the configuration in which the moving distance of the stage is extended to 2 m to 3 m, the plate It is difficult to ensure the static and dynamic stability of the stage only by the elastic deformation amount of the spring.

  Furthermore, when the upper surface accuracy of the surface plate cannot be ensured due to an increase in the size of the stage device, or when the guide portion is supported on the gantry instead of on the surface plate, the parallelism of the pair of guide portions is obtained. Is difficult.

Therefore, when the flat line of the pair of guide portions can not be controlled with high precision, or decrease translation accuracy of the pair of sliders also lag behind relative position of the pair of sliders arranged on the left and right ends of the stage, or There is a possibility that the hydrostatic bearing pad provided on the slider may come into contact with the guide portion.

  Therefore, in view of the above circumstances, an object of the present invention is to provide a stage apparatus that solves the above problems.

  In order to solve the above problems, the present invention has the following means.

The present invention includes a plurality of mounts fixed to the floor, a pair of guide portions supported in parallel by the plurality of mounts, and horizontally mounted between the pair of guide portions, both ends of which are attached to the mounts. A plurality of supported beams, a workpiece placement plate supported by the plurality of beams, a pair of sliders that move along the extending direction of the pair of guide portions, and a pair of sliders are horizontally mounted A stage that moves above the workpiece mounting plate, a pair of linear motors that drive the pair of sliders, a pair of linear scales that measure the moving position of the stage, A control unit that controls the pair of linear motors so that the movement positions measured by the pair of linear scales are equal, and the plurality of beams are in contact with the side surfaces of the pair of guide units. Supported by the plurality of mounts By a solves the above problems.

Further, the present invention provides an elevating mechanism for adjusting the height position of the horizontal portion, and a height for measuring the height position of the horizontal portion with respect to the upper surface of the work placing plate placed on the plurality of beams. A direction detection sensor, storage means for storing the relationship between the measurement data detected by the height direction detection sensor and the movement position of the stage, and measurement data corresponding to the movement position of the stage stored in the storage means And a lift control means for controlling the lift mechanism on the basis of movement position data measured by the linear scale.

Moreover, it is preferable that the horizontal portion is rotatably connected to the slider.
Further, the present invention includes a plurality of frame fixed to the floor, a pair of guide portions arranged in parallel is supported by a plurality of frame, is laterally placed between the pair of guide portions, both ends wherein A plurality of beams supported by the gantry in contact with the side surfaces of the pair of guide portions, a workpiece placement plate supported by the plurality of beams, and moved along the extending direction of the pair of guide portions A pair of sliders, a horizontal part that is horizontally placed between the pair of sliders, a stage that moves above the workpiece placement plate, a pair of linear motors that drive the pair of sliders, It solves the above-mentioned subject.

According to the present invention, a plurality of beams are horizontally mounted between a pair of guide portions that are supported and arranged in parallel by a plurality of mounts, and the work placing plate is supported by the plurality of beams that are supported by the mounts at both ends. In addition, since the plurality of beams are supported by the plurality of mounts in a state where both ends are in contact with the side surfaces of the pair of guide portions , the stone surface plate is moved to the workpiece size in order to move the stage above the workpiece placing plate. Depending on the degree of orthogonality between the beam and the side of the guide part, both ends of a plurality of beams abut against the side of the pair of guide parts without using a stone surface plate. Thus, the accuracy of the parallelism of the pair of guide portions can be increased, and the workpiece can be increased in size.

  In addition, according to the present invention, in order to control the lifting mechanism based on the measurement data corresponding to the movement position of the stage stored in the storage means and the movement position data measured by the linear scale, the parallel movement of the pair of guide portions is performed. Even when a deviation occurs, the slider can be moved so that the height position of the slider that moves above the workpiece placement plate is maintained at a predetermined height position set in advance.

  In addition, according to the present invention, since the horizontal portion is rotatably connected to the slider, the horizontal portion is bent even when a relative positional shift occurs when the slider of the stage is translated. Can be prevented.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing an embodiment of a stage apparatus according to the present invention. FIG. 2 is a front view of the stage apparatus shown in FIG. FIG. 3 is a side view of the stage apparatus shown in FIG. 4 is a plan view of the stage apparatus shown in FIG.

  As shown in FIGS. 1 to 4, the stage device 10 is a gantry moving stage that moves a gantry section. The stage device 10 includes a gantry 12 fixed on a concrete floor, and a pair of gantry units supported on the gantry 12. It moves in the Y direction along the pair of guide portions 14A and 14B, a plurality of beams 16 that are horizontally mounted between the pair of guide portions 14A and 14B and supported at both ends on the mount 12, and the pair of guide portions 14A and 14B. The Y stage 18 has a pair of linear motors 20A and 20B that drive both ends of the Y stage 18 in the Y direction. A pair of linear scales 22A and 22B for detecting the position of the Y stage 18 are provided on the upper left and right side surfaces of the left guide portion 14A.

  In addition, a suction plate 24 (work placement plate) on which a flat work (workpiece) made of a liquid crystal substrate or the like is placed is placed on the beam 16. The guide portions 14A and 14B are supported by the gantry 12 and aligned and arranged in parallel by the beam 16 so that the separation distance in the X direction is constant.

  The pair of guide portions 14A and 14B are made by processing a stone material or processing a metal material such as iron. Therefore, even when the area of the workpiece is increased and the moving distance of the Y stage 18 is extended, it is possible to cope with the problem by extending the entire length of the guide portions 14A and 14B. It is easier than extending a stone surface plate having a large area according to the area according to the moving distance, and it is not necessary to manufacture a stone surface plate according to the work area as in the prior art. Can be manufactured at low cost.

  The pair of linear motors 20A and 20B are controlled to be driven in translation based on position detection signals from the pair of linear scales 22A and 22B that detect the movement position of the Y stage 18.

  As shown in FIG. 2, the Y stage 18 includes a horizontal portion (beam) 30 that is horizontally mounted in the X direction above the guide portions 14A and 14B, and guide portions 14A, 14A, 14B that are coupled to both ends of the horizontal portion 30. 14B, and a pair of sliders 32A and 32B that move along 14B. The sliders 32A and 32B are provided with elevating mechanisms 33A and 33B for elevating the horizontal portion 30 and adjusting the height position. In addition, a jig 60 for performing a predetermined operation on a work (not shown) adsorbed on the adsorbing plate 24 or an inspection after processing is mounted on the horizontal portion 30.

  Further, the horizontal portion 30 is provided with height direction detection sensors 70A and 70B for detecting a distance (Z direction position data) from the upper surface of the suction plate 24. The height direction detection sensors 70A and 70B are composed of, for example, an ultrasonic sensor, and can measure a distance from a time difference from when an ultrasonic wave is transmitted until when a reflected wave is received. The flatness of the upper surface of the suction plate 24 is processed with high accuracy and can be used as a reference surface for profile control.

  The guide portions 14A and 14B are adjusted in height by the gantry 12 so as to be horizontal, and are set so as to be parallel by the beam 16. However, one of the guide portions 14A and 14B is horizontal due to a minute error. If this is not the case, a deviation may occur in the Z-axis direction. In this case, the Y stage 18 may fluctuate (vibrate) in the Z-axis direction in the process of moving in the Y direction while being in a horizontal state above the suction plate 24, and the distance between the jig 60 and the upper surface of the suction plate 24. Is no longer constant. In order to suppress such variation in the Z-axis direction of the Y stage 18 by the guide portions 14A and 14B, in the stage apparatus 10, the Z-axis direction between the upper surface of the suction plate 24 and the horizontal portion 30 with respect to each movement position in the Y direction. The relative distance is measured in advance, and the elevating mechanisms 33A and 33B are operated based on the Z-axis direction measurement data, and control is performed so that the distance between the jig 60 and the upper surface of the suction plate 24 becomes constant.

  Of the guide portions 14A and 14B, the left guide portion 14A guides the movement of the slider 32A, and the right guide portion 14B guides the movement of the slider 32B. The sliders 32 </ b> A and 32 </ b> B are formed in an inverted U shape so as to face the left and right side surfaces and the upper surface of the guide portion 14, and the yaw pads (Y-direction hydrostatic air bearings) 34 facing the left and right side surfaces of the guide portions 14 </ b> A and 14 </ b> B. , 35 and a lift pad (Z direction hydrostatic air bearing) 36 facing in the Z direction. Therefore, the sliders 32A and 32B are guided in the Y direction while being restricted in the X direction and the Z direction.

  A pair of linear scales 22A and 22B that detect the position of the slider 32A on one side are provided on the left and right sides of the upper portion of the guide portion 14 that guides the movement of the slider 32A. The first linear scale 22A measures the moving position of the slider 32A relative to the left side surface of the guide portion 14A. The second linear scale 22B measures the moving position of the slider 32A with respect to the right side surface on the opposite side parallel to the left side surface of the guide portion 14A on which the first linear scale 22A is arranged.

  The first and second yaw pads 34 and 35 are arranged in the vicinity of the first and second linear scales 22A and 22B, respectively, and suppress variations in detection accuracy of the first and second linear scales 22A and 22B. is doing.

  The pair of linear scales 22A and 22B is, for example, a photoelectric type, and includes a sensor having a light emitting element and a light receiving element and a scale having slits with a constant pitch. In the present embodiment, the sensor is provided on the left and right inner walls of the slider 32 </ b> A, and the scale is attached to the left and right side surfaces of the guide portion 14.

  Further, the horizontal portion 30 and the sliders 32A and 32B are lifted and moved in a non-contact manner with respect to the guide portions 14A and 14B by the air pressure from the lift pad 36. Therefore, the Y stage 18 can move in the Y direction with almost no friction.

  The linear motors 20A and 20B are composed of a stator (having a permanent magnet) 40 formed in a U-shape and a mover (having a coil) 42 inserted into the stator 40 from the side. The coil applied voltage is controlled so as to move the mover 42 in the Y direction in a non-contact state through a minute gap. The mover 42 is coupled to the side surfaces of the sliders 32A and 32B, and the thrust generated between the stator 40 and the stator 40 when a voltage is applied to the coils is transmitted to the sliders 32A and 32B. Drive in the Y direction.

  Further, the stator 40 of the linear motors 20 </ b> A and 20 </ b> B is supported by a linear motor support portion 46. Therefore, the reaction force generated when the Y stage 18 is moved in the Y direction by the driving force of the linear motors 20 </ b> A and 20 </ b> B is transmitted to the concrete floor via the linear motor support 46.

  Thereby, the reaction force which linear motor 20A, 20B receives is attenuate | damped by a concrete floor surface. Accordingly, the reaction force of the linear motors 20A and 20B transmitted to the gantry 12 is extremely small.

  FIG. 5 is a block diagram for explaining a control system of the stage apparatus 10. As shown in FIG. 5, the control device 100 of the stage apparatus 10 includes the linear motors 20A and 20B, the linear scales 22A and 22B, the height direction detection sensors 70A and 70B, and the Z axis that drives the lifting mechanisms 33A and 33B. Motors 80A and 80B and a storage device 90 are connected. The control device 100 measures the Y direction position data measured by the linear scales 22A and 22B in the process of moving the Y stage 18 in the Y direction, and the height direction detection sensors 70A and 70B corresponding to the Y direction position data. The Z-axis data table 92 that associates the Z-direction position data is created and stored in the storage device 90. The creation of the Z-axis data table 92 may be performed, for example, every time the workpiece is replaced, or may be updated every predetermined time determined in advance.

  Then, the control device 100 reads Z-direction position data corresponding to the Y-direction position data measured by the linear scales 22A and 22B from the Z-axis data table 92 stored in the storage device 90, and sets the Z-axis motors 80A and 80B. A program (elevation control means) is preliminarily controlled so as to be controlled.

  The pair of guide portions 14A and 14B are aligned and arranged in parallel so that the separation distance in the X direction becomes constant by the beam 16, but an error may occur in the parallelism. For example, when the distance in the X direction between the pair of guide portions 14A and 14B is narrowed or widened depending on the position in the Y direction, the position in the Z direction of the pair of guide portions 14A and 14B is increased depending on the position in the Y direction. Or located below.

  When such an error occurs in the parallelism of the pair of guide portions 14A and 14B, the distance between the jig 60 mounted on the Y stage 18 and the suction plate 24 fluctuates, and is attracted to the suction plate 24. Processing accuracy and inspection accuracy for a workpiece (not shown) will be reduced. However, in the present invention, when the Y stage 18 is moved in the Y direction, the control device 100 reads the Z-direction position data corresponding to the Y-direction position data from the Z-axis data table 92 stored in the storage device 90, and the lifting mechanism Since the Z-axis motors 80A and 80B of the 33A and 33B are controlled, it is possible to suppress the variation in the Z direction due to an error in the parallelism of the guide portions 14A and 14B to almost zero. That is, when the control device 100 measures the Z-direction position data in which the sliders 32A and 32B moving along the guide portions 14A and 14B move in the vertical direction in the process of moving the Y stage 18 in the Y direction, When passing through the Y-direction position, the Z-axis motors 80A and 80B are driven to adjust the height position of the horizontal portion 30 in the direction opposite to the Z-direction position data. It is possible to control the distance to be constant.

  FIG. 6 is a front view showing a modification. As shown in FIG. 6, the left guide portion 14A of the guide portions 14A, 14B is wider than the right guide portion 14B in the X direction and wider than the above embodiment. Therefore, the difference between the detection position of the linear scale 22A and the detection position of the linear scale 22B is enlarged, and the yaw angle θ of the Y stage 18 is easily detected.

  Further, the connecting shaft 50 erected from the slider 32 </ b> B is inserted into the through hole 30 a provided at the right end of the horizontal portion 30. Therefore, the right end of the horizontal portion 30 and the slider 32B are coupled via a vertical coupling shaft 50 so as to enable a turning operation in the yaw direction.

  Further, the right slider 32B is not provided with the yaw pads 34 and 35, and only the lift pad 36 facing in the Z direction is provided. Therefore, the slider 32B is guided in the Y direction in a state where only the floating position in the Z direction of the guide portion 14B is restricted.

  For example, the sliders when the parallelism of the guide portions 14A and 14B is shifted, when one of the guide portions 14A and 14B has a warp in the X direction, or when the translation operation of the pair of sliders 32A and 32B is shifted. 32B can be rotated around the Z axis around the connecting shaft 50 to correct the moving direction and prevent the horizontal portion 30 from being bent.

  In the above-described embodiment, the stage apparatus that processes a workpiece made of a liquid crystal substrate or the like has been described as an example. Of course you can.

It is a perspective view which shows one Example of the stage apparatus by this invention. It is a front view of the stage apparatus shown in FIG. It is a side view of the stage apparatus shown in FIG. It is a top view of the stage apparatus shown in FIG. 3 is a block diagram for explaining a control system of the stage apparatus 10. FIG. It is a front view which shows a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Stage apparatus 12 Base 14A, 14B Guide part 18 Y stage 20A, 20B Linear motor 22A, 22B Linear scale 30 Horizontal part 32A, 32B Slider 33A, 33B Lifting mechanism 46 Linear motor support part 60 Jigs 70A, 70B Height direction Detection sensor 80A, 80B Z-axis motor 90 Storage device 92 Z-axis data table 100 Control device

Claims (4)

A plurality of mounts fixed to the floor;
A pair of guide portions supported in parallel by the plurality of mounts and arranged in parallel;
A plurality of beams that are horizontally mounted between the pair of guide portions and whose both ends are supported by the frame;
A workpiece mounting plate supported by the plurality of beams;
A pair of sliders that move along the extending direction of the pair of guide portions;
A stage that horizontally spans between the pair of sliders, and a stage that moves above the workpiece mounting plate;
A pair of linear motors for driving the pair of sliders;
A pair of linear scales for measuring the moving position of the stage;
A control unit that controls the pair of linear motors so that the movement positions measured by the pair of linear scales are equal;
Equipped with a,
The stage apparatus , wherein the plurality of beams are supported by the plurality of mounts in a state where both ends thereof are in contact with the side surfaces of the pair of guide portions . An elevating mechanism for adjusting the height position of the horizontal portion;
A height direction detection sensor for measuring the height position of the horizontal portion with respect to the upper surface of the work placing plate placed on the plurality of beams;
Storage means for storing the relationship between the measurement data detected by the height direction detection sensor and the moving position of the stage;
Elevating control means for controlling the elevating mechanism according to measurement data corresponding to the movement position of the stage stored in the storage means and movement position data measured by the linear scale;
The stage apparatus according to claim 1, further comprising: The horizontal bridging portion, the stage apparatus according to claim 1 or 2, characterized in that it is linked to the slider and rotating. A plurality of mounts fixed to the floor;
A pair of guide portions supported in parallel by the plurality of mounts and arranged in parallel;
A plurality of beams horizontally supported between the pair of guide portions and supported by the gantry in a state where both ends are in contact with the side surfaces of the pair of guide portions ;
A workpiece mounting plate supported by the plurality of beams;
A pair of sliders that move along the extending direction of the pair of guide parts, and a horizontal part that is horizontally mounted between the pair of sliders, and a stage that moves above the workpiece mounting plate;
A pair of linear motors for driving the pair of sliders;
A stage apparatus comprising:

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