JPH1094925A - Movement guide device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remarkably reduce the unnecessary tilt of a movable body, by symmetrically installing a hydrostatic bearing and plural pre-load mechanisms, on a face opposite to a reference plane of the second movable body which is two-dimensionally moved. SOLUTION: A Y stage 4 is floated from a level block 1 by supplying the air to a hydrostatic air bearing, and is moved in the Y direction along a fixed guide 2 by two driving actuators 4c. Further a X stage 5 is floated from the level block 1 as is the case with the Y stage 4, by supplying the air to the hydrostatic air bearing, and is moved in the X direction by a driving actuator 5c while guided by a side face of the Y stage 4 in the transverse direction. On this occasion, the X stage and the Y stage are respectively adjusted to keep the constant positions by plural magnetic units for pre-load installed on the rear faces thereof, and four hydrostatic bearings installed on four corners of each stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving guide device, and more particularly to a moving guide device capable of positioning a moving body such as a stage at a predetermined position at a high speed and with high accuracy, particularly in a semiconductor manufacturing apparatus or a precision machine tool. It is about.

[0002]

2. Description of the Related Art Conventionally, various types of moving guide devices have been proposed in which a moving body is moved along a predetermined guide and positioned at a predetermined position with high accuracy.

FIG. 8 is a perspective view of a main part of a movement guide device having a conventional X, Y movement mechanism.

[0004] In the figure, reference numeral 81 denotes a surface plate.
A Y stage 84 as a moving mechanism in the Y direction is mounted on 1. On the Y stage 84, an X stage 85 as a moving mechanism in the X direction is mounted.

The X stage 85 and the Y stage 84 are moved and positioned in predetermined directions by driving means such as a linear motor (not shown).

[0006]

The movement guide device shown in FIG. 1 includes a surface plate 81, a Y stage 84, and an X stage 85.
, It tends to be higher in the vertical direction.

When the X stage 85 moves, an eccentric load is generated on the Y stage 84, and the Y stage 84 is deformed, for example, as shown by the dotted lines in FIGS. 9A and 9B. There is a drawback that the static attitude accuracy of No. 85 deteriorates.

Further, when the X stage 85 and the Y stage 84 are made of rigid bodies, the X stage 85 and the Y stage 84 have six degrees of freedom as shown in FIG.
For example, when the Y stage 84 causes pitching, the X stage 85 rolls. For example, there are problems in that all six degrees of freedom are coupled to each other, and the posture accuracy is dynamically degraded.

According to the present invention, the unnecessary inclination of the moving body is reduced, and unnecessary vibration of one moving body is prevented from affecting the other moving body. It is an object of the present invention to provide a movement guide device capable of performing accurate positioning.

[0010]

According to the present invention, there is provided a movement guide device comprising: a surface plate having a reference surface; a first moving body moving in a first direction (Y direction) along the reference surface; A first hydrostatic bearing 3d for supporting the first moving body with respect to the reference plane in a direction perpendicular to a plane, and moving in the first direction by moving the first moving body in the first direction; ,
A second moving two-dimensionally along the reference plane by moving in the second direction (X direction) with respect to the first moving body;
A moving body 5, a second hydrostatic bearing 3a for transmitting the movement of the first moving body in the first direction to the second moving body, and the second moving body in a direction perpendicular to the reference plane; A third static pressure bearing 3b supported on a reference surface, and a first preload for applying a preload to the first moving member toward the reference surface in order to keep a constant attitude of the first moving member with respect to the reference surface. A second precompression mechanism that applies a preload to the second moving body toward the reference plane in order to maintain a constant posture of the second moving body with respect to the reference plane; The body includes a plurality of first bearing mounting plates 5f respectively provided on both sides of the first moving body in the first direction for mounting the second hydrostatic bearing, and the reference for mounting the third hydrostatic bearing. Of the first moving body and the reference plane with respect to a direction perpendicular to the plane. Located in, it has a second bearing mounting plate 5e connected to each of the plurality of first bearing mounting plate,
The second preload mechanism is mounted on the second bearing mounting plate, and four third hydrostatic bearings 3b and a plurality of second preload mechanisms are provided on a surface of the second bearing mounting plate facing the reference surface. It is characterized by being arranged symmetrically.

In particular, four first hydrostatic bearings 3d and a plurality of first preload mechanisms 6a are symmetrically arranged on a surface of the first moving body 4 facing the reference surface. I have.

Further, the first and second preload mechanisms have a magnet for applying a preload by a magnetic force.

The first moving body and the second moving body are each driven by a linear motor.

[0014]

1 to 4 show a first embodiment of the present invention.
FIG.

FIG. 1 is a perspective view, FIG. 2 is a sectional view taken along line AA 'of FIG. 1, FIG. 3 is a sectional view taken along line BB' of FIG. 1, and FIG. 4 is a transparent perspective view of FIG.

In FIG. 1, reference numeral 1 denotes a surface plate, the upper surface of which is a smooth reference surface. 4 is a moving body in the Y direction (first
The Y stage, which is a constituent member of the moving body, and the X stage, 2 which is a constituent member of the moving body (second moving body) in the X direction.
Are fixed guides in the lateral direction (Y-axis direction) of the Y stage 4;
(3a, 3b, 3c, 3d) are porous hydrostatic air bearings, of which 3a is a lateral direction (Y-axis direction) of the X stage 5 as a second hydrostatic bearing, and 3b is a third hydrostatic bearing. In the vertical direction of the X stage 5, 3c is in the lateral direction of the Y stage 4 as a fourth hydrostatic bearing, and 3d is Y in the first hydrostatic bearing.
The stage 4 is guided in the vertical direction. 4a is the first
The horizontal static pressure air bearing mounting plate 4b of the Y stage 4 as a static pressure bearing is a vertical static pressure air bearing mounting plate of the Y stage 4 and also serves as a horizontal guide of the X stage 5. Reference numeral 4c denotes a drive actuator for the Y stage, and reference numeral 4d denotes a connecting plate of the drive actuator 4c for the Y stage, which is connected to the hydrostatic air bearing mounting plate 4a. 5a is a moving plate of the X stage 5, 5b is a bearing mounting plate in the vertical and lateral directions of the X stage 5, and 5c is a drive actuator of the X stage 5. Reference numeral 6 (6a, 6b) denotes a preload magnet unit which is, as proposed in Japanese Patent Application No. 62-62735, a preload mechanism having, for example, permanent magnets as magnetic force means and yokes provided on both sides thereof. When the moving body is levitated by supplying the pressurized fluid to the static pressure bearing, the moving body is prevented from tilting due to variations in the characteristics of the bearing, and is always kept in a fixed posture.

Here, as shown in FIG. 4, reference numeral 6a denotes a first preload mechanism, which is provided on the Y stage 4 in a plurality (four).
In order to keep the attitude of the stage (first moving body) 4 with respect to the reference plane constant, a preload is applied to the Y stage toward the reference plane.

Reference numeral 6b denotes a second preload mechanism, which is provided on the X stage (second moving body) 5 in a plurality (four), and is directed toward the reference surface in order to keep the attitude of the X stage 5 relative to the reference surface constant. Preload is applied to the X stage.

As shown in FIG. 4, four static pressure air bearings 3d are arranged at four corners of the static pressure air bearing mounting plate 4b of the first moving body, and are formed at four corners of the bearing mounting plate 5b of the second moving body. Four static pressure air bearings 3b are arranged, and a plurality of preload mechanisms 6 are provided.
Together with (6a, 6b), they are arranged symmetrically with respect to the X and Y movement directions.

In the present embodiment, the driving actuator 4
As c and 5c, for example, a linear motor, a hydraulic DC motor, or the like is used.

In this embodiment, the Y stage 4 is floated from the surface plate 1 by supplying air to the static pressure air bearing 3d.
It is moved in the Y direction along the fixed guide 2 by two drive actuators 4c.

The X stage 5 is provided with a hydrostatic air bearing 3b, 3
By supplying air to a, it floats above the surface plate 1 like the Y stage 4, and the side surface of the Y stage 4 is moved in the X direction by the drive actuator 5c as a lateral guide. At this time, as shown in FIG. 4, the X stage 5 and the Y stage 4 are always fixed by a plurality of preload magnet units 6 provided on the back surface thereof and four hydrostatic bearings arranged at four corners of each stage. The posture is adjusted.

The features of this embodiment are as follows: (a) Both the X stage and the Y stage are guided in the vertical (gravity) direction (Z direction) from the surface plate. No static load is maintained by avoiding a moving load on the stage.

(B) Three components of vibration in the vertical direction (X direction in FIG. 1), vertical (gravity) direction (Z direction in FIG. 1), and rolling (rotation about the Y axis in FIG. 1) of the Y stage are linked. I have lost everything.

(C) Y stage pitching (X in FIG. 1)
Rotation about the axis) is transmitted only to the X stage via the static pressure air bearing 3a, thereby suppressing the coupling as much as possible.

(D) Compared with the conventional moving guide device shown in FIG. 9, the area occupied by the surface plate is made substantially equal by overhanging the X stage with the fixed guide 2 or the drive actuator 4c for the Y stage.

(E) The height of the entire movement guide device, including the surface plate, is reduced to about 1/2 of the conventional height.

(F) By adjusting the height of the connecting plate 4d, the driving points of the X stage and the Y stage, the X stage, and the Y
The center of gravity in the height direction of the stage is made substantially coincident, thereby suppressing vibration during driving as much as possible.

(G) By making the width of the horizontal static pressure air bearing mounting plate 4a of the Y stage (Y direction) longer than the width of the vertical static pressure air bearing mounting plate 4b, the area of the horizontal bearing mounting plate is increased. Is enough. At this time, the length of the horizontal hydrostatic air bearing mounting plate 4a is set to the moving plate 5 of the X stage 5.
The length is matched with the length a, thereby preventing the movable area from expanding.

FIGS. 5 to 7 are schematic diagrams of Embodiment 2 of the present invention. FIGS. 5, 6, and 7 correspond to FIGS. 2, 3, and 4 of the first embodiment, respectively.

In this embodiment, the same members as those in the first embodiment are denoted by the same reference numerals.

In FIGS. 5 to 7, reference numeral 4e denotes a vertical and horizontal bearing mounting plate, and 4f denotes a connecting plate for the horizontal guide of the X stage 5 and the bearing mounting plate 4e. 5e is a vertical bearing mounting plate (second bearing mounting plate) of the X stage 5, and 5f is a lateral bearing mounting plate (first bearing mounting plate) of the X stage 5.

Here, as shown in FIGS. 5 and 7, the surface of the bearing mounting plate (second bearing mounting plate) 5e facing the reference surface
One third hydrostatic bearing 3b and a plurality of second preload mechanisms 6b are arranged symmetrically with respect to the moving direction.

As shown in FIG. 7, a plurality of first preload mechanisms 6a are provided on the Y stage (first moving body) 4 apart from each other in the X direction (second direction). 6b is provided on the X stage 5 so as to be located between the Y stage and the reference plane in a direction perpendicular to the reference plane.

As shown in FIGS. 5, 6, and 7, four static pressure air bearings 3d are arranged at four corners of the bearing mounting plate 4e of the first moving body 4, and the bearings of the second moving body 5 are provided. Four static pressure air bearings 3b are arranged at four corners of the mounting plate 5e, and are arranged symmetrically with respect to the X and Y movement directions together with the plurality of preload mechanisms 6.

In this embodiment, by providing a vertical bearing mounting plate (second bearing mounting plate) 5e on the X stage 5, in addition to the features of the first embodiment, for example, the horizontal static pressure of the X stage 5 When air is supplied to the air bearing 3a, the bearing mounting plate (first bearing mounting plate) 5f and the moving plate 5a are prevented from bending and deforming, and the moving plate 5a, the bearing mounting plate 5e,
The thickness of members such as 5f is reduced.

Further, by appropriately setting the thickness of the bearing mounting plate 5e in the vertical (gravity) direction, the position of the center of gravity of the X stage 5 can be adjusted. It has features such as easy matching.

[0038]

According to the moving guide device of the present invention, both the first and second moving bodies are supported by the hydrostatic bearing on the same reference plane, and the preload mechanism is provided on both the first and second moving bodies. Provided on the surface facing the reference surface of the second moving body that moves two-dimensionally.
Since two hydrostatic bearings and a plurality of second preload mechanisms are symmetrically arranged, even if acceleration occurs in each direction due to two-dimensional movement, unnecessary inclination of the moving body can be extremely small and extremely high. Accurate positioning becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a main part of a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA ′ of FIG. 1;

FIG. 3 is a sectional view taken along line BB ′ of FIG. 1;

FIG. 4 is a rear perspective view of FIG. 1;

FIG. 5 is a schematic sectional view of Embodiment 2 of the present invention.

FIG. 6 is a schematic cross-sectional view of Embodiment 2 of the present invention.

FIG. 7 is a rear perspective view of Embodiment 2 of the present invention.

FIG. 8 is a schematic view of a main part of a conventional movement guide device.

FIG. 9 is an explanatory view of a part of a conventional movement guide device.

FIG. 10 is an explanatory diagram of a vibration mode.

[Explanation of symbols]

 Reference Signs List 1 surface plate 2 lateral fixed guide 3 (3a, 3b, 3c, 3d) static pressure air bearing 4 Y stage 5 X stage 5a moving plate 4a, 4b static pressure air bearing mounting plate 4c, 5c drive actuator 4d connecting plate 6 Preload magnet unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuo Horikoshi 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Kazuya Ono 53 Imaiue-cho, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Canon Inc.

Claims (4)

[Claims] 1. A surface plate having a reference plane, a first moving body that moves in a first direction along the reference plane, and the first moving body with respect to the reference plane in a direction perpendicular to the reference plane. A first hydrostatic bearing for supporting the first moving body in the first direction by moving the first moving body in the first direction, and by moving the first moving body in the second direction with respect to the first moving body. A second moving body that moves two-dimensionally along a reference plane; a second hydrostatic bearing that transmits movement of the first moving body in the first direction to the second moving body; A third supporting the second moving body with respect to the reference plane in a vertical direction;
A static pressure bearing, a first preload mechanism for applying a preload to the first moving body toward the reference plane in order to maintain a constant attitude of the first moving body with respect to the reference plane, and A second preload mechanism for applying a preload to the second moving body toward the reference plane in order to maintain a constant attitude with respect to the reference plane, wherein the second moving body is used to mount the second hydrostatic bearing. A plurality of first bearing mounting plates provided on both sides of the first moving body with respect to the first direction; and the first moving body with respect to a direction perpendicular to the reference plane for mounting the third hydrostatic bearing. A second bearing mounting plate located between the reference surfaces and connected to each of the plurality of first bearing mounting plates, wherein a second preload mechanism is mounted on the second bearing mounting plate; On the surface of the second bearing mounting plate facing the reference surface, One of the mobile guide device hydrostatic bearing and a plurality of second preload mechanism is characterized in that it is arranged symmetrically. 2. The apparatus according to claim 1, wherein four first static pressure bearings and a plurality of first preload mechanisms are symmetrically arranged on a surface of the first moving body facing the reference surface. Item 2. The movement guide device according to Item 1. 3. The movement guide device according to claim 1, wherein the first and second preload mechanisms include a magnet for applying a preload by a magnetic force. 4. The apparatus according to claim 1, wherein the first moving body and the second moving body are each driven by a linear motor.
The movement guide device according to the above.