JP7600631B2 - Table device - Google Patents

Description

The present invention relates to a table device used in semiconductor manufacturing and inspection equipment.

Various table devices for precision movement and positioning have been known in the past. The table device shown in Patent Document 1 moves and positions within a plane, and has a base guide arranged in parallel, a movable guide supported so as to be able to reciprocate in the guide direction relative to the base guide, and a table supported so as to be able to reciprocate in the guide direction relative to the movable guide. Both base guides and the movable guide are configured as linear motors consisting of a motor yoke and a coil bobbin, and an air bearing that supports the XYZ axis load applied to the coil bobbin is configured between each motor yoke and the coil bobbin. The table device shown in Patent Document 2 has bearing members that form an air bearing arranged one by one at the four corners of the table that is rectangular in plan view (see each air pad 253 in Figure 17). Each bearing member forms an air bearing by facing the guide surface of the base member, which is the mating member, with a small gap between them.

Japanese Unexamined Patent Publication No. 182692/1983 JP 2002-082445 A

In the table device described in Patent Document 2, when the table simultaneously moves in the X-axis and Y-axis directions parallel to the horizontal plane (i.e., when it moves diagonally in both the X-axis and Y-axis directions), the load is concentrated on one bearing member located at the corner of the table due to the inertial force caused by the acceleration and deceleration of the table as it moves. As a result, the gap between the bearing member on which the load is concentrated and the guide surface that forms the gas bearing becomes smaller, and the table tilts relative to the horizontal direction, making it impossible to increase the acceleration and deceleration of the table. Furthermore, if the table tilts significantly, the end face of the bearing member comes into contact with the guide surface of the base member, which can cause wear and seizure in the bearing member and base member.

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to provide a table device that can increase the acceleration and deceleration of the table by suppressing the tilt of the table that occurs when the table moves simultaneously in the X-axis and Y-axis directions.

The above object of the present invention can be achieved by the following configuration.
(1) A table device comprising: a base member having a guide surface parallel to a predetermined plane; a table having a rectangular shape in a plan view that is placed on the base member; and a table support portion that is placed at each of the four corners of the table and supports the table movably in a direction along the guide surface, the table support portion comprising a plurality of bearing members that form gas bearings between the base member and the table.
(2) The table device described in (1), wherein the table support portion includes three of the bearing members, and the three bearing members are arranged in an approximately L-shape along the corner portion of the table.
(3) A table device according to (1) or (2), further comprising a suction member that sucks the base member against the table, the suction member being disposed between adjacent table support portions.

According to the present invention, a table support is provided at each of the four corners of the table, and supports the table movably in a direction along the guide surface. The table support has a plurality of bearing members that form a gas bearing between the base member and the table, so that the load applied to the corners of the table during table movement can be supported by the plurality of bearing members. This makes it possible to suppress the tilt of the table that occurs when the table moves simultaneously in the X-axis and Y-axis directions. As a result, it becomes possible to increase the acceleration and deceleration of the table, and to speed up the movement of the table. This makes it possible to shorten the cycle time (processing time, inspection time) of manufacturing equipment and inspection equipment using the table device of the present invention, thereby improving productivity.

1 is a side view illustrating an embodiment of a table device according to the present invention. FIG. 2 is a bottom view of the table device shown in FIG. 1 . 1. FIG. 4 is a bottom view illustrating a modified example of the table device shown in FIG.

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 this embodiment, the XY plane is parallel to the horizontal plane. The Z axis direction is vertical. 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 bottom view of the table device 10 according to this embodiment, as viewed from the -Z side. Note that in Figure 1, 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 that is rectangular in plan view and is placed on the base member 1, and table support parts 20 that are placed at each of the four corners 2a of the table 2. The table 2 is moved in two directions, the X-axis direction and the Y-axis direction, relative to the base member 1 by a drive system (not shown).

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, a cast iron surface plate, or a ceramic 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.

As shown in FIG. 2, the table 2 is disposed above the base member 1 (in the +Z direction). The table 2 is movable and supports the object S. In this embodiment, the external shape of the table 2 is a square along the X-axis and Y-axis directions.

As shown in FIG. 1, the table support section 20 has a plurality of bearing members 21 (three for each gas bearing 21G in this embodiment, for a total of 12 on the table 2) that form gas bearings 21G between the base member 1 and the table 2. In this embodiment, the three bearing members 21 are arranged in a substantially L-shape along the corners 2a of the table 2 as shown in FIG. 2. The table support section 20 supports the table 2 movably in a direction along the guide surface 1A of the base member 1 (at least one of the X-axis direction and the Y-axis direction) by the gas bearings 21G formed by the bearing members 21.

The bearing member 21 forms a gas bearing (hydrostatic bearing) 21G between the base member 1 and the table 2. In this embodiment, the bearing member 21 is disposed on the underside of the table 2 facing the guide surface 1A of the base member 1. By forming the gas bearing 21G, the table 2 is supported on the guide surface 1A of the base member 1 without contact. The base member 1 supports the table 2 in a non-contact manner in the X-axis direction and the Y-axis direction by the gas bearing 21G formed by the bearing member 21. In this embodiment, the gas bearing 21G is formed by supplying compressed air sent from a compressor (not shown) from the bearing member 21 toward the base member 1. Note that the bearing member 21 is not limited to a circular shape, and may be a polygonal shape such as a square shape.

In this embodiment, the bearing member 21 includes 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 also be made of ceramics. In this embodiment, gas is supplied from holes (supply ports) in the porous body.

1 and 2, vacuum suction members 30 are provided between adjacent table support parts 20 in the X-axis direction and the Y-axis direction on the table 2. In this embodiment, the vacuum suction member 30 is disposed on the underside of the table 2. The vacuum suction member 30 is vacuum-suctioned by a suction pump (not shown) to keep the internal space of the vacuum suction member 30 in a negative pressure state, thereby sucking the base member 1 against the table 2. The vacuum suction member 30 applies a preload to the levitation force of the multiple bearing members 21 to increase the rigidity of the gas bearing 21G (preventing the table 2 from floating in the +Z-axis direction). Furthermore, the vacuum suction member 30 has a function of discharging a part of the gas (compressed air supplied from the bearing member 21) supplied between the underside of the table 2 and the guide surface 1A of the base member 1 to the outside by vacuum suction. In addition, a magnetic suction method using a magnet may be used as a means for applying a preload to the gas bearing 21G. If the lifting force of the bearing member 21 is to be balanced with the weight of the table device 10, the vacuum suction member 30 does not need to be provided.

As described above, according to the table device 10 of this embodiment, since multiple bearing members 21 are provided at each of the four corners 2a of the table 2, the load applied to the corners 2a of the table 2 during table movement can be supported by the multiple bearing members 21. This makes it possible to suppress the tilt of the table 2 that occurs when the table 2 moves simultaneously in the X-axis and Y-axis directions. As a result, it becomes possible to increase the acceleration and deceleration of the table 2 and the object S supported by the table 2, and the movement of the table 2 can be made faster. This makes it possible to shorten the cycle time (processing time, inspection time) of the manufacturing device and inspection device using the table device 10, thereby improving productivity.

In addition, according to the table device 10 of this embodiment, the three bearing members 21 are arranged in a substantially L-shape along the corner 2a of the table 2, so that the load applied to the corner 2a of the table 2 during table movement can be efficiently supported. This further reduces the tilt of the table 2 that occurs when the table 2 moves simultaneously in the X-axis and Y-axis directions.

As a modification of this embodiment, the table support 20 may be composed of two bearing members 21, as shown in FIG. 3. In this modification, the two bearing members 21 are arranged symmetrically with respect to the diagonal of the table 2.

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, the number of bearing members constituting the table support portion is not limited to the above-mentioned two or three, but may be four or more depending on the size of the table.
Furthermore, as long as a plurality of bearing members are arranged symmetrically with respect to the diagonal line of the table, the bearing members may differ in size, shape, and amount of air supplied thereto.
Furthermore, the table may be provided with one or more through holes penetrating the table in the Z-axis direction in a portion that does not overlap with the table support portion and the vacuum suction member, thereby making it possible to reduce the weight of the table and to further increase the acceleration and deceleration speed.

REFERENCE SIGNS LIST 10 Table device 1 Base member 1A Guide surface 2 Table 2a Corner portion 20 Table support portion 21 Bearing member 21G Gas bearing 30 Vacuum suction member S Object

Claims (2)

A base member having a guide surface parallel to a predetermined surface;
A table having a rectangular shape in a plan view and disposed on the base member;
a table support portion disposed at each of the four corners of the table and supporting the table movably in a direction along the guide surface;
the table support includes three bearing members forming a gas bearing between the base member and the table ;
The three bearing members are arranged in a substantially L-shape along the corners of the table.
Table equipment. a suction member that sucks the base member against the table,
The table apparatus according to claim 1 , wherein the suction member is disposed between adjacent ones of the table support portions.

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