JP3651358B2 - Stage unit drive mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drive mechanism for a stage apparatus that moves three axes of XYθ applicable to various machines and instruments such as an optical machine such as an exposure apparatus, a measuring instrument, a machine tool, and a screen printer, and in particular, a precise XYθ direction. The present invention relates to a stage apparatus drive mechanism suitable for application to an exposure apparatus that requires a very small movement.
[0002]
[Prior art]
As a stage apparatus that can easily control in the XYθ directions using one stage, for example, a stage apparatus described in Japanese Patent Laid-Open No. 8-25163 has been proposed.
FIG. 6 shows the stage apparatus described in FIG. 1 of the above publication. In the figure, a stage 20 is placed on a base 21 via a flat guide 22 so as to be movable in the XYθ directions. In the following, as shown in the figure, the X direction is the left and right direction in the figure, the Y direction is the up and down direction in the figure, and “moving in the θ direction” means rotating about an axis perpendicular to the XY plane. .
A through window is provided in the central portion of the stage 20 and the base 21. For example, a mask is placed on the stage 20, and the mask is irradiated with light from a light source (not shown) and placed on a work stage (not shown). For example, the exposure processing of the workpiece is performed.
Reference numerals 23, 24, and 25 denote first to third drive elements. The drive elements 23, 24, and 25 include actuators such as motors, the drive units 23a and 25a are in the X direction, and the drive unit 24a is in the Y direction. To drive. The distal ends of the drive units 23a, 24a, and 25a are formed of flat guides, and are in contact with driven elements attached to the arms 20a, 20b, and 20c of the stage 20. In this example, the driven elements are rollers 23b, 24b, and 25b.
Reference numeral 26 denotes a spring. One end of the spring 26 is fixed, and the other end is biased so as to press the arms 20a, 20b, and 20c of the stage 20 in the directions of the drive elements 23, 24, and 25.
[0003]
In FIG. 6, the stage 20 is driven as follows.
When the stage 20 is moved in the X direction, the first and third drive elements 23 and 25 are driven to move the drive units 23a and 25a by an equal amount in the X direction. Thereby, the roller 24b attached to the arm 20b of the stage 20 moves along the driving unit 24a, and the stage 20 moves in the X direction.
In order to move the stage 20 in the Y direction, the first and third driving elements 23 and 25 are not driven, but the second driving element 24 is driven to move the driving unit 24a. Thereby, the rollers 23b and 25b attached to the arms 20a and 20c of the stage 20 move along the drive units 23a and 25a, and the stage 20 moves in the Y direction.
[0004]
When the stage 20 is moved (rotated) in the θ direction, the driving units 24a and 25a are moved in the first direction (for example, the driving units 24a and 25a are respectively moved by the second and third driving elements 24 and 25). Driving in the direction in which the arms 20b, 20c of the stage 20 are pushed, and the first driving element 23 causes the driving unit 23a to move in a direction opposite to the first direction (for example, the driving unit 23a pulls the arm 20a of the stage 20). ) To drive. For example, when the stage is rotated in the clockwise direction, when the driving unit pushes the arm in the + direction and the pulling direction is in the-direction, the driving unit 24a is driven in the + X direction, and the driving unit 25a is driven in the + Y direction. The drive unit 23a is driven in the −X direction. Thereby, the stage 20 rotates around the intersection of a line A1 connecting the shafts 23d and 25d of the rollers 23b and 25b and a line A2 passing through the shaft 24d of the roller 24c and orthogonal to the moving direction of the driving unit 24a (this rotation). The center is called the reference axis).
[0005]
FIG. 7 shows another example of the configuration of the stage apparatus shown in FIG. 6 of Japanese Patent Laid-Open No. 8-25163.
In the same figure, similarly to FIG. 6, a stage 20 is placed on a base 21 via a flat guide 22 so as to be movable in the XYθ directions.
Reference numerals 23, 24, and 25 denote first to third drive elements that drive the drive units 23a and 25a in the X direction and the drive unit 24a in the Y direction. Slide shafts 23e, 24e, and 25e are attached to the distal ends of the drive units 23a, 24a, and 25a, and rotation and slide members 23f, 24f, and 25f are driven on the arms 20a, 20b, and 20c of the stage 20 as driven elements. It is attached. The rotation and slide members 23f, 24f, and 25f are attached to the arms 20a, 20b, and 20c so as to be rotatable about the rotation shafts 23g, 24g, and 25g, and are slidable with respect to the slide shafts 23e, 24e, and 25e. (Note that the rotation and slide members 23f, 24f, and 25f in FIG. 7 show the cross sections of the portions through which the slide shafts 23e, 24e, and 25e pass). Although not shown in FIG. 7, similarly to FIG. 6, the arms 20a, 20b, 20c of the stage 20 are urged in the direction of the drive units 23a, 24a, 25a by springs (not shown).
[0006]
In the case shown in FIG. 7, as in FIG. 6, when the stage 20 is moved in the X direction, the first and third driving elements 23 and 25 are driven to drive the driving units 23a and 25a by an equal amount. Move in the direction of the arrow in the figure. Further, in order to move the stage 20 in the Y direction, the first and third drive elements 23 and 25 are not driven, but the second drive element 24 is driven and the drive unit 24a is moved.
Further, when the stage 20 is moved (rotated) in the θ direction, the driving units 24a and 25a are moved in the first direction (for example, the driving units 24a and 25a are respectively moved by the second and third driving elements 24 and 25). Driving in the direction in which the arms 20b, 20c of the stage 20 are pushed, and the first driving element 23 causes the driving unit 23a to move in a direction opposite to the first direction (for example, the driving unit 23a pulls the arm 20a of the stage 20). ) To drive. As a result, the stage 20 rotates around the reference axis described above.
[0007]
[Problems to be solved by the invention]
The stage apparatus shown in FIGS. 6 and 7 has the following problems.
(1) As shown in FIG. 6, when the driven element is a roller attached to the stage via a rotating shaft, the following problems occur.
(1) The eccentricity of the rotating shaft with respect to the center of the roller.
As shown in FIG. 8 (a), if the processing position of the hole through which the rotation shafts 23d, 24d, and 25d pass is deviated from the true center position of the rollers 23b, 24b, and 25b, the stage 20 meanders and moves. To do.
(2) The inclination of the rotation axis of the roller in the plane of the drive element.
As shown in FIG. 8B, when the rotation shafts 23d, 24d, and 25d of the rollers 23b, 24b, and 25b are inclined in the rolling direction of the roller with respect to the axis perpendicular to the moving plane of the stage 20 by the flat guide 22. When the stage 20 moves horizontally, a force that presses the stage 20 against the planar guide 22 or lifts the stage 20 from the planar guide 22 acts, thereby inhibiting smooth movement of the stage 20.
(3) Difference in parallelism between the roller side surface and the flat surface of the drive element.
As shown in FIG. 8C, the corners of the rollers 23b, 24b, and 25b are in contact with the flat portions of the drive units 23a, 24a, and 25a, so that the stage 20 is linearly moved depending on the chamfering state of the rollers 23b, 24b, and 25b. Is damaged.
In order to prevent the above problems, the rotation axis of the roller is processed so as not to be decentered with respect to the center of the roller, and the rotation axis of the roller is further perpendicular to the moving plane of the stage by the plane guide. Assembling so that the parallelism between the flat surface and the side surface of the roller is precisely matched requires high processing and assembly accuracy, which increases the cost of the stage apparatus.
[0008]
(2) As shown in FIG. 7, when the driving element and the driven element are composed of a slide shaft, a rotation and a slide member, the problem of roller eccentricity can be solved. However, processing and assembly are difficult as described below.
(1) In FIG. 7, the rotation shafts 23g, 24g, 25g of the rotation and slide members 23f, 24f, 25f, which are driven elements, must be perpendicular to the moving plane of the stage 20.
{Circle around (2)} Also, the slide shafts 23e, 24e, 25e, which are driving elements, must be parallel to the moving plane of the stage 20.
If there is a deviation in the above (1) or (2), the rotation and sliding movement of the slide members 23f, 24f, 25f and the slide shafts 23e, 24e, 25e are hindered, so that the stage 20 can move smoothly. In extreme cases, it cannot move. This will be described below with reference to FIG.
9A is a perspective view of the slide shafts 23e, 24e, and 25e and the rotation and slide members 23f, 24f, and 25f, and FIG. 9B is the slide shafts 23e, 24e, and 25e and the rotation and slide members. It is an enlarged view of the engaging part of 23f, 24f, 25f. As shown in the figure, the rotation and slide members 23f, 24f, and 25f are provided with cylindrical through holes, and the slide shafts 23e, 24e, and 25e pass through the through holes.
[0009]
Here, the difference in (1) or (2) means that the slide shafts 23e, 24e, 25e and the rotation shafts 23g, 24g, 25g of the rotation and slide members 23f, 24f, 25f are perpendicular to each other. It is not. Therefore, as the stage 20 moves, as shown in FIG. 9B, the slide shafts 23e, 24e, and 25e come into contact with the inner wall of the through hole to generate friction, thereby inhibiting smooth movement. become unable.
However, “Assembly of the rotation shaft holes of the rotation and slide members 23f, 24f, and 25f so as to be perpendicular to the moving plane of the stage 20”, “The slide shafts 23e, 24e, and 25e are parallel to the moving plane. “Assembling the members to which the slide shafts 23e, 24e, and 25e are attached” means that “the rotation and the holes of the rotation shafts of the slide members 23f, 24f, and 25f are engaged with the slide shafts 23e, 24e, and 25e”. It is difficult because it requires advanced and skilled technology along with processing the through hole to have a high degree of straightness.
[0010]
The present invention has been made in view of the above circumstances, and an object of the present invention is to drive a stage device that moves the stage in the XYθ direction when the driving element presses the driven element provided on the stage. Therefore, it is necessary to provide a stage mechanism drive mechanism that does not require machining of parts with high accuracy and does not require advanced and skilled techniques in the assembly of the apparatus.
[0011]
[Means for Solving the Problems]
In the present invention, the above problems are solved as follows.
Driven by two or more drive elements whose drive directions are parallel, one or more drive elements whose drive directions are orthogonal to the drive direction of the drive elements, and linearly move in two directions At the same time, in the stage apparatus constituted by the stage rotating around the set reference axis, the drive mechanism is configured as follows.
An actuating member is provided in the driving part of the driving element, and a driven member that is pushed by the actuating member is provided on the stage, and either the actuating member or the driven member is connected to the driving part of the driving element by the rotating shaft or It is attached to the stage so that it can swing. The actuating member and the driven member are in contact with each other via at least two balls and a retainer that rotatably accommodates the balls, and either the actuating member or the driven member surrounds the periphery of the retainer. Provide a frame.
Since the present invention is configured such that the operating member and the driven member are in contact with each other via two balls as described above, the rotation of the operating member or the driven member attached so as to be swingable with respect to the moving plane of the stage. Even if the axis is not strictly vertical, the stage can be moved in the XYθ direction along the driving element. Therefore, advanced and skilled techniques are not required in assembling the apparatus.
In addition, since the number of points where the driven element and the driving element come into contact can be increased to six or more, the rigidity of the stage device can be increased.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
1 shows a configuration of a stage apparatus according to the embodiment of the present invention shown in FIG. In the figure, a stage 20 is placed on a base 21 via a flat guide 22 so as to be movable in the XYθ directions.
The center portion of the stage 20 and the base 21 is provided with a through window as described above. As described above, for example, a mask is placed on the stage 20 and light is applied to the mask from a light source (not shown). The exposure processing of the workpiece placed on the workpiece stage not to be performed is performed.
Reference numerals 23, 24, and 25 denote first to third drive elements. The drive elements 23, 24, and 25 include actuators such as motors, the drive units 23a and 25a are in the X direction, and the drive unit 24a is in the Y direction. To drive. The tips of the drive units 23a, 24a, and 25a are constituted by flat plates 1a, 1b, and 1c (this is called an operation member) perpendicular to the drive direction. Further, rotating members 23h, 24h, and 25h, which are driven elements, are attached to the arms 20a, 20b, and 20c of the stage 20. The rotating members 23h, 24h, and 25h are attached to the arms 20a, 20b, and 20c via the rotating shafts 23i, 24i, and 25i, and are rotatable about the rotating shafts.
A spring 26 is attached to the stage 20, the other end of the spring 26 is fixed to the base 21, and the arms 20 a, 20 b, and 20 c of the stage 20 are moved by the spring 26 to the first to third driving elements 23, 24, It is urged in the direction of pressing against 25.
The parts of the rotating members 23h, 24h, 25h, which are driven elements, that come into contact with the flat plates 1a, 1b, 1c (actuating members) of the driving parts 23a, 24a, 25a are configured as shown in FIG. .
[0013]
2, (a) is an enlarged view of the rotating members 23h, 24h, and 25h in FIG. 1, (b) is a view of (a) seen from the A direction, and (c) is seen from the B direction. It is a figure.
As shown in the figure, the surfaces of the rotating elements 23h, 24h, 25h on the driving element side are rectangular flat plates 2a, 2b, 2c perpendicular to the moving plane of the stage 20 (referred to as driven members). A retainer frame 3 slightly protruding from the surfaces of the flat plates 2a, 2b, and 2c is provided in the periphery of the flat plates 2a, 2b, and 2c.
In the retainer frame 3, two balls 4 having the same diameter arranged substantially parallel to the moving plane of the stage 20 are accommodated so that the two balls 4 can be rotated by the retainer 5 and do not contact each other. The flat plates 1a, 1b, 1c (operating members) and the flat plates 2a, 2b, 2c (driven members) are in contact with each other via the balls 4 and the retainers 5. Further, the diameter of the ball 4 is slightly larger than the height of the retainer frame 3.
[0014]
The relationship between the size of the retainer 5 and the retainer frame 3 is set as shown in FIG. That is, with respect to the moving direction of the stage 20, a clearance α corresponding to the moving amount of the stage 20 (for example, XY direction ± 7 mm, θ direction ± 2 °) is provided on both sides of the retainer 5, and the moving direction of the stage In the direction perpendicular to the gap δ is provided on both sides.
The portion on the driving element side (acting member) with which the ball 4 abuts is a rectangular flat plate perpendicular to the moving plane of the stage 20 as described above.
[0015]
The above configuration has the following advantages.
The actuating members (flat plates 1a, 1b, 1c) of the driving element and the driven members (flat plates 2a, 2b, 2c) of the driven element are each two balls arranged substantially parallel to the moving plane of the stage 20 4 is in contact.
Therefore, the rotation shafts 23i, 24i, 25i of the rotation members 23h, 24h, 25h may not be strictly perpendicular to the moving plane of the stage 20. Further, the surfaces of the balls 4a and 4b in contact with each other may be slightly inclined as long as the flatness is maintained.
For this reason, a highly skilled technique is not required for assembly. This will be described below.
[0016]
3 and 4 show a case where the rotating shafts 23i, 24i, and 25i of the rotating members 23h, 24h, and 25h are attached to the moving plane of the stage 20 slightly obliquely.
In the case of FIG. 3, when the stage 20 is driven and moved by the drive elements 23, 24, 25, the retainer frame 3 moves obliquely with respect to the retainer 5. However, since the retainer 5 can freely move in the retainer frame 3, the movement of the stage 20 is not hindered.
In the case of FIG. 4, even if the parallelism between the driven member of the driven element (flat plates 2a, 2b, 2c) and the actuating member of the driving element 23, 24, 25 (flat plate 1a, 1b, 1c) is slightly worse, Since both are in contact with each other by the ball 4, the poor parallelism is absorbed and there is no functional problem. Therefore, accurate XYθ movement of the stage 20 is possible.
[0017]
In addition, in order to perform accurate XYθ movement, the sphericity of the ball 4 needs to be good, but a ball with good sphericity can be obtained relatively easily, and it is not necessary to align the sphere diameters so accurately. So it does not increase the cost.
In this embodiment, there are six points where the driven element and the driving element come into contact. In the case where the roller shown in the conventional example (for example, FIG. 1 of JP-A-8-25163) is a driven element, there are three contact points, but in this embodiment there are six contact points. The applied force is dispersed to reduce the distortion of the ball, and the rigidity of the contact surface can be increased.
When used in a stage device of a large-sized liquid crystal substrate or printed circuit board exposure apparatus, the stage device itself is large and heavy, so it is necessary to increase the rigidity. However, according to this embodiment, the contact point is increased compared to the conventional case. Therefore, it is effective in increasing the rigidity. If further rigidity is required, the number of balls may be increased and the number of contact points may be 6 or more. For example, if three balls are provided in one retainer frame, there are nine contact points as a whole, and the rigidity can be further increased.
[0018]
In the above embodiment, the case where the retainer frame, the retainer, and the ball are provided on the driven member side has been described. However, the retainer frame, the retainer, and the ball may be attached to the operating member side.
In the above embodiment, the case where the rotating members 23h, 24h, and 25h are attached to the stage arms 20a, 20b, and 20c has been described. However, the rotating members 23h, 24h, and 25h are disposed on the drive elements 23, 24, and 25 side. It may be attached.
That is, as shown in FIG. 5, the rotating members 23h, 24h, 25h provided with the retainer frame 3 are attached to the drive element side, and the tips of the stage arms 20a, 20b, 20c are moved with respect to the moving plane of the stage. It may be configured by vertical rectangular flat plates 2a, 2b, 2c.
[0019]
【The invention's effect】
As described above, the following effects can be obtained in the present invention.
(1) Since the driving element and the driven element are in contact with each other via two balls arranged substantially parallel to the moving plane of the stage, the driven machine is in contact with the moving plane of the stage. Even if the rotation axis of the element is not strictly vertical, the stage can be moved along the driving element by XYθ. Therefore, advanced and skilled techniques are not required in processing such as the degree of straightness of parts and assembly of devices.
(2) The number of points where the driven element and the driving element come into contact can be six or more. For this reason, the rigidity of the stage device can be increased.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a stage apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing a configuration of a retainer frame, a retainer, and a ball provided on a rotating member.
FIG. 3 is a diagram showing a case (1) in which a rotation axis of a rotating member is attached slightly oblique to a moving plane of a stage.
FIG. 4 is a diagram showing a case (2) in which the rotation axis of the rotating member is attached slightly obliquely with respect to the moving plane of the stage.
FIG. 5 is a diagram showing another configuration example in which a rotating member is attached to the driving element side.
FIG. 6 is a diagram showing a configuration example (1) of a stage apparatus shown in a conventional example.
FIG. 7 is a diagram showing a configuration example (2) of the stage apparatus shown in the conventional example.
FIG. 8 is a diagram for explaining a problem of the conventional stage apparatus shown in FIG.
9 is a diagram for explaining a problem of the conventional stage apparatus shown in FIG.
[Explanation of symbols]
1a, 1b, 1c Flat plate (actuating member)
2a, 2b, 2c Flat plate (driven member)
3 Retainer frame 4 Ball 5 Retainer 20 Stage 21 Base 22 Planar guides 23, 24, 25 First to third drive elements 23a, 24a, 25a Drive units 20a, 20b, 20c Arms 23h, 24h, 25h Rotating member 23i , 24i, 25i rotation axis

Claims (1)

Two or more driving elements whose driving directions are parallel, and one or more driving elements whose driving directions are orthogonal to the driving direction of the driving elements;
A stage mechanism drive mechanism configured by a stage driven by the drive element and linearly moving in two directions and rotating about a set reference axis;
The drive unit of the drive element is provided with an actuating member, and the stage is provided with a driven member that is pushed by the actuating member,
Either one of the actuating member and the driven member is swingably attached to the driving unit of the driving element or the stage via a rotating shaft,
The actuating member and the follower member are in contact with each other via at least two balls and a retainer that rotatably accommodates the balls, and either the actuating member or the follower member surrounds the retainer. A drive mechanism for a stage apparatus, comprising a frame.

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