JP7582028B2 - Table device - Google Patents

Description

The present invention relates to a table device.

In technical fields related to semiconductor manufacturing equipment, inspection equipment, and measurement equipment, table devices (stage devices) equipped with tables that can move in three dimensions are used. For example, the table device described in Patent Document 1 is equipped with a bearing member that forms a gas bearing on the underside of a cylinder member so as to face the guide surface of a base member, and the action of this gas bearing allows the table to move in a non-contact state relative to the guide surface. In addition, an exhaust port is provided between the lower end opening of the internal space of the cylinder member and the bearing member. Furthermore, the table device is equipped with a gravity compensation device having a supply port that supplies gas to a lower space below the underside of a piston member connected to the table.

JP 2015-196222 A

In the table device of the above-mentioned Patent Document 1, the movable stage (Y-axis stage) constituting part of the drive system for moving the table is directly connected to four cylinder members arranged at each corner of the table, so that the movable stage and the four cylinder members move together along the XY plane (horizontal plane). Therefore, the four cylinder members may tilt in the vertical direction (Z-axis direction) around the movable stage due to the inertial force caused by the acceleration and deceleration when the movable stage and the four cylinder members move together, so it was not possible to increase the acceleration and deceleration of the movable stage. If the cylinder members are tilted significantly, the lower end of the cylinder members will come into contact with the guide surface of the base member, which may cause wear and seizure on the cylinder members and base members. In addition, a method of increasing the rigidity of the gas bearing on the lower surface of the cylinder members can be considered to suppress the tilt of the cylinder members, but this would entail an increase in the size and mass of the table device, so in this case too, it is difficult to increase the acceleration and deceleration of the movable stage.

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to provide a table device that can suppress the tilt of the cylinder member that accompanies the movement of the movable stage and increase the acceleration and deceleration of the movable stage.

The above object of the present invention can be achieved by the following configuration.
(1) A base member having a guide surface parallel to a predetermined plane, a table disposed on the base member, a drive system disposed between the base member and the table in a direction parallel to a first axis perpendicular to the predetermined plane, and capable of moving the table in a direction parallel to the first axis, a direction parallel to a second axis in the predetermined plane, and a direction parallel to a third axis perpendicular to the second axis in the predetermined plane, and a drive system disposed on a periphery of the table, supporting the table movably in the direction parallel to the first axis, and supporting the table movably in each of a direction parallel to the second axis and a direction parallel to the third axis. and a plurality of table support devices connected to the table, the drive system comprising a movable stage movable in a direction parallel to the second axis and a direction parallel to the third axis, the table support device comprising a piston member connected to the table, a cylinder member having an internal space for accommodating the piston member, and a bearing member disposed on a surface of the cylinder member opposite the guide surface and forming a gas bearing between the cylinder member and the guide surface, the movable stage and the cylinder members of the plurality of table support devices being connected by a plurality of elastic members elastically deformable in a direction parallel to the first axis.
(2) The table device according to (1), wherein the elastic member biases the cylinder member toward the base member.
(3) The table device according to (1) or (2), wherein the elastic member is a leaf spring.

According to the present invention, the movable stage, which is arranged to be movable in a direction parallel to the second axis and a direction parallel to the third axis, and the cylinder members of the multiple table support devices are connected by multiple elastic members that are elastically deformable in a direction parallel to the first axis, so that the tilt of the cylinder members that accompanies the movement of the movable stage is suppressed, and the acceleration and deceleration of the movable stage can be increased.

1 is a partially cutaway side view illustrating a first embodiment of a table device according to the present invention; FIG. 2 is a top view of the table device shown in FIG. 1 .

Below, one embodiment of the table device according to the present invention will be described in detail with reference to the drawings.

In the following description, an XYZ Cartesian coordinate system is set, and the positional relationship of each part is described with reference to this XYZ Cartesian coordinate system. The direction parallel to the first axis perpendicular to the specified plane is the Z axis direction, the direction parallel to the second axis in the specified plane is the X axis direction, and the direction parallel to the third axis perpendicular to the second axis in the specified plane is the Y axis direction. The Z axis (first axis) is perpendicular to each of the X axis (second axis) and the Y axis (third axis). The X axis is perpendicular to the YZ plane. The Y axis is perpendicular to the XZ plane. The Z axis is perpendicular to the XY plane. The XY plane is parallel to the specified plane. In each embodiment, the XY plane is parallel to the horizontal plane. The Z axis direction is the vertical direction. The XY plane (specified plane) may be inclined with respect to the horizontal plane.

Figure 1 is a side view of the table device 10 according to this embodiment, as viewed from the -Y side. Figure 2 is a plan view of the table device 10 according to this embodiment, as viewed from the +Z side. Note that in Figure 1, a portion of the table device 10 is shown in cross section. In this embodiment, the +Z side is the upper side, and the -Z side is the lower side.

As shown in Figures 1 and 2, the table device 10 includes a base member 1, a table 2 arranged on the base member 1, a drive system 3 arranged between the base member 1 and the table 2 in the Z-axis direction and capable of moving the table 2, and four table support devices 15 arranged on the periphery of the table 2.

The base member 1 has a guide surface 1A, which is an upper surface parallel to the XY plane (a specified surface). The guide surface 1A is flat. The base member 1 may be a stone surface plate such as Indian Black, or a cast iron surface plate. The base member 1 is placed, for example, on the floor surface of a facility (e.g., a factory) in which the table device 10 is installed.

The table 2 is disposed above the base member 1 (in the +Z direction). The table 2 is movable while supporting an object S. With the object S placed on the upper surface of the table 2, the table 2 is movable in three directions, the X-axis direction, the Y-axis direction, and the Z-axis direction. In this embodiment, the table 2 is a three-degree-of-freedom table (three-axis table, three-dimensional table) that can move in three directions. In this embodiment, the external shape of the table 2 in the XY plane is a rectangle (square).

The drive system 3 includes a Z-axis drive unit 3A connected to the center of the underside of the table 2 and moving the table 2 in the Z-axis direction, an X-axis drive unit 3B arranged on the upper surface of the base member 1 and moving the table 2 in the X-axis direction, a Y-axis drive unit 3C arranged on the upper surface of the X-axis drive unit 3B and moving the table 2 in the Y-axis direction, and a horizontal plane movable stage (movable stage) 25 arranged between the Z-axis drive unit 3A and the Y-axis drive unit 3C and movable in the X-axis direction and the Y-axis direction by the X-axis drive unit 3B and the Y-axis drive unit 3C. Therefore, the drive system 3 can move the table 2 in three directions, the X-axis direction, the Y-axis direction, and the Z-axis direction. In addition, the drive system 3 can move the table 2 in an oblique direction that combines the movement in the X-axis direction and the movement in the Y-axis direction. In this embodiment, the external shape of the horizontal plane movable stage 25 in the XY plane is a quadrangle (square). In addition, detailed structures of the Z-axis drive unit 3A, the X-axis drive unit 3B, and the Y-axis drive unit 3C are not shown in Figure 1, and well-known structures are applied. For example, in the Z-axis drive unit 3A, the first wedge member 11 is driven in the X-axis direction by an actuator (not shown) attached to the horizontal plane movable stage 25, thereby moving the second wedge member 12 in the Z-axis direction.

1, the table support device 15 includes a piston member 4 connected to the table 2, a cylinder member 5 having an internal space 5H for accommodating the piston member 4, a bearing member 6 forming a gas bearing 6G between the piston member 4 and the cylinder member 5, and a bearing member 7 forming a gas bearing 7G between the base member 1 and the cylinder member 5. The table support device 15 supports the table 2 movably in the Z-axis direction by the gas bearing 6G formed by the bearing member 6, and supports the table 2 movably in each of the X-axis and Y-axis directions by the gas bearing 7G formed by the bearing member 7. The axes of the piston member 4 and the cylinder member 5 are parallel to the Z-axis. The number of table support devices 15 is not limited to four and can be set arbitrarily.

The piston member 4 is a cylindrical member that is long in the Z-axis direction. The piston member 4 is connected to the underside of the table 2. In this embodiment, the upper surface of the piston member 4 is connected to the underside of the table 2 via a connecting member 40. In addition, the piston member 4 is arranged coaxially with the cylinder member 5.

In addition, in this embodiment, the piston members 4 are connected to the four corners of the underside of the table 2, which is the peripheral portion of the table 2. In other words, the four table support devices 15 are arranged to surround the drive system 3.

The cylinder member 5 is a cylindrical member and has an internal space 5H that houses the piston member 4. The cylinder member 5 also has a connecting member 30 at approximately the middle in the Z-axis direction. The connecting member 30 is a plate-shaped member that connects two adjacent cylinder members 5 in the Y-axis direction. The connecting member 30 constitutes a part of the cylinder member 5, and the internal space 5H is formed not only in the cylinder member 5 but also in the connecting member 30. The connecting member 30 may be annular so as to connect four cylinder members 5.

The bearing member 6 forms a gas bearing (hydrostatic bearing) 6G between the piston member 4 and the cylinder member 5. In this embodiment, the bearing member 6 is disposed on the inner surface of the cylinder member 5 so as to face the internal space 5H of the cylinder member 5. By forming the gas bearing 6G, the piston member 4 is supported in a non-contact manner on the inner surface of the cylinder member 5. The cylinder member 5 supports the piston member 4 in a non-contact manner in the Z-axis direction by the gas bearing 6G formed by the bearing member 6. In this embodiment, compressed air is supplied to the bearing member 6, and the gas bearing 6G is formed by this compressed air.

The bearing member 7 forms a gas bearing (hydrostatic bearing) 7G between the base member 1 and the cylinder member 5. In this embodiment, the bearing member 7 is disposed on the underside of the cylinder member 5 facing the guide surface 1A of the base member 1. By forming the gas bearing 7G, the cylinder member 5 is supported in a non-contact manner on the guide surface 1A of the base member 1. The base member 1 supports the cylinder member 5 in a non-contact manner in the X-axis and Y-axis directions by the gas bearing 7G formed by the bearing member 7. In this embodiment, compressed air is supplied to the bearing member 7, and the gas bearing 7G is formed by this compressed air.

In this embodiment, the bearing member 6 and the bearing member 7 include a porous body (porous member). The porous body may be made of graphite (carbon graphite), for example, as disclosed in Japanese Patent No. 5093056 and Japanese Patent Application Laid-Open No. 2007-120527. The porous body may be made of ceramics. In this embodiment, gas is supplied from holes (supply ports) in the porous body.

As shown in FIG. 1, the lower end of the cylinder member 5 is provided with a supply port 5S that supplies compressed air to the space below the lower surface of the piston member 4 within the internal space 5H. The piston member 4 is lifted by the pressure of the compressed air supplied from the supply port 5S, so that the effect of the weight of the table 2 on the drive system 3 can be reduced. Compressed air from the compressor 20 is supplied to the supply port 5S via a pressure regulator 21. In other words, the supply port 5S of the cylinder member 5, the compressor 20, and the pressure regulator 21 constitute a gravity compensation mechanism that reduces the effect of the weight of the table 2 on the drive system 3.

The lower surface of the cylinder member 5 is provided with an exhaust port 5E that exhausts a portion of the gas (compressed air) supplied between the lower surface of the cylinder member 5 and the guide surface 1A of the base member 1 to the outside by vacuum suction. The exhaust port 5E has the function of applying a preload to the levitation force of the bearing member 7. A magnetic suction method may also be used as a means of applying a preload to the levitation force. If rigidity is not required for the gas bearing 7G formed by the bearing member 7, the exhaust port 5E does not need to be provided.

Furthermore, in the table device 10 of this embodiment, as shown in Figures 1 and 2, the horizontal plane movable stage 25 and the two connecting members 30 that form part of the four cylinder members 5 are connected by four leaf springs (elastic members) 35 that are elastically deformable in the Z-axis direction.

The leaf springs 35 are connected to each of the four corners of the upper surface of the horizontal plane movable stage 25. The ends of the leaf springs 35 are attached to the horizontal plane movable stage 25 or the connecting members 30 by fastening members 36 such as bolts or rivets. The leaf springs 35 are also arranged approximately parallel to the XY plane (horizontal plane). Since the leaf springs 35 have rigidity in the X-axis and Y-axis directions, they can reliably transmit the driving forces of the horizontal plane movable stage 25 in the X-axis and Y-axis directions to the four cylinder members 5.

The leaf springs 35 are arranged to bias the cylinder member 5 (connecting member 30) towards the base member 1. The method of attachment of the leaf springs 35 is not limited to fastening members, but may be welding, etc. The number of leaf springs 35 is not limited to four, but may be set arbitrarily. In order to increase the biasing force of the leaf springs 35 on the cylinder member 5, the leaf springs 35 may be attached so as to slope downward from the horizontal plane movable stage 25 towards the cylinder member 5. In this case, the leaf springs 35 may be curved in advance.

In the table device 10 configured in this manner, the horizontal plane movable stage 25 and the four cylinder members 5 are connected by four leaf springs 35 that can elastically deform in the Z-axis direction. When the horizontal plane movable stage 25 moves in the X-axis direction and the Y-axis direction, the four leaf springs 35 function as rigid bodies, so that the horizontal plane movable stage 25 and the four cylinder members 5 move together. At this time, the four cylinder members 5 tend to tilt in the vertical direction (Z-axis direction) around the horizontal plane movable stage 25 due to the inertial force associated with the acceleration and deceleration of the horizontal plane movable stage 25 and the four cylinder members 5 as they move together, but the movement associated with the tilt of the four cylinder members 5 is absorbed by the elastic deformation of the four leaf springs 35 in the Z-axis direction. This suppresses the tilt of the cylinder members 5, making it possible to increase the acceleration and deceleration of the horizontal plane movable stage 25, and to speed up the movement of the table 2.

As described above, according to the table device 10 of this embodiment, the horizontal plane movable stage 25 and the cylinder members 5 of the four table support devices 15 are connected by four leaf springs 35 that are elastically deformable in the Z-axis direction, so that the tilt of the cylinder members 5 that accompanies the movement of the horizontal plane movable stage 25 can be suppressed, and the acceleration/deceleration of the horizontal plane movable stage 25 can be increased. This allows the movement of the table 2 to be accelerated.

In addition, according to the table device 10 of this embodiment, the leaf spring 35 biases the cylinder member 5 toward the base member 1, so that a preload can be applied to the gas bearing 7G, thereby increasing the rigidity of the gas bearing 7G.

The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist of the present invention.
For example, in the above embodiment, the elastic member is a leaf spring, but is not limited to this and can be changed to any elastic member that is elastically deformable in the Z-axis direction.
In addition, in the above embodiment, the leaf spring is attached to a connecting member that connects the two cylinder members, but this is not limited to this. For example, the leaf spring may be attached directly to the cylinder member by providing a flange or the like on the cylinder member.

REFERENCE SIGNS LIST 10 Table device 1 Base member 1A Guide surface 2 Table 3 Drive system 3A Z-axis drive device 3B X-axis drive device 3C Y-axis drive device 4 Piston member 5 Cylinder member 5H Internal space 5S Supply port 5E Exhaust port 6 Bearing member 6G Gas bearing 7 Bearing member 7G Gas bearing 15 Table support device 20 Compressor 21 Pressure regulator 25 Horizontal plane movable stage (movable stage)
30 Connecting member 35 Leaf spring (elastic member)
36 Fastening member 40 Connection member

Claims (2)

A base member having a guide surface parallel to a predetermined surface;
a table disposed on the base member;
a drive system disposed between the base member and the table in a direction parallel to a first axis perpendicular to the predetermined plane, the drive system being capable of moving the table in a direction parallel to the first axis, a direction parallel to a second axis in the predetermined plane, and a direction parallel to a third axis perpendicular to the second axis in the predetermined plane;
a plurality of table support devices disposed on a periphery of the table, supporting the table movably in a direction parallel to the first axis, and supporting the table movably in each of a direction parallel to the second axis and a direction parallel to the third axis;
the drive system includes a movable stage that is movable in a direction parallel to the second axis and a direction parallel to the third axis;
The table support device is
a piston member connected to the table;
a cylinder member having an internal space for accommodating the piston member;
a bearing member disposed on a surface of the cylinder member facing the guide surface, the bearing member forming a gas bearing between the bearing member and the guide surface,
the movable stage and the cylinder members of the plurality of table support devices are connected by a plurality of elastic members so as to be relatively movable in a direction parallel to the first axis ;
The elastic member biases the cylinder member toward the base member.
Table equipment. The table apparatus according to claim 1 , wherein the elastic member is a leaf spring.

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