JP3145355B2 - Travel guidance device - Google Patents

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 method for positioning a moving body such as an X stage or a Y stage at a predetermined position at a high speed and with high precision in a semiconductor manufacturing apparatus or a precision machine tool. The present invention relates to a movable guide device that can be used.

[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. 7 is a perspective view of a main part of a movement guide device having a conventional X, Y movement mechanism. In the figure, reference numeral 71 denotes a surface plate, and Y
A Y stage 74 as a direction moving mechanism is mounted. On the Y stage 74, an X stage 75 as a moving mechanism in the X direction is mounted.

The X stage 75 and the Y stage 74 are moved and positioned in predetermined directions by driving means such as a linear motor (not shown).

[0004]

Since the conventional moving guide device shown in FIG. 7 has a structure in which the surface plate 71, the Y stage 74 and the X stage 75 are sequentially stacked, there is a drawback that the height is increased in the vertical direction. Was.

When the X stage 75 moves, an eccentric load is generated on the Y stage 74, and the Y stage 74 is deformed, for example, as shown by the dotted lines in FIGS. There is a drawback that the static attitude accuracy of 75 deteriorates.

Further, when the X stage 75 and the Y stage 74 are made of a rigid body, the X stage 75 and the Y stage 74 have six degrees of freedom as shown in FIG. There are problems such as the rolling of the X stage 75, all six degrees of freedom being coupled to each other, and the posture accuracy is dynamically degraded.

An XY moving mechanism guided by static pressure is disclosed in, for example, JP-A-62-88526 and JP-A-1-1882.
No. 41, and the like. However, in the conventional configuration, if the surface plate and the stage are not formed of the same member, the bearing gap changes when the temperature changes during driving of the stage, so that the control characteristics change and a smooth positioning operation can be performed. Did not. Further, in an environment in which temperature changes are large, such as during transportation, there is a possibility that the bearing gap is lost due to thermal expansion or the like, and the hydrostatic bearing, stage, or surface plate is damaged.

The present invention is a further improvement of the above-mentioned prior art. By appropriately setting a guide mechanism of a stage which moves two-dimensionally, the stage can be damaged even if a temperature change occurs during transportation or use. It is an object of the present invention to provide a movement guide device which enables high-precision positioning without causing a change in control characteristics and the like.

In addition, the present invention is directed to, for example, three directions: a direction perpendicular to the movement of the Y stage, a vertical direction, and rolling.
The object of the present invention is to provide a movement guide device which eliminates the coupling of vibration in the components and transmits the pitching of the Y stage only to the X stage via the gap of the hydrostatic air bearing, thereby enabling highly accurate positioning. And

It is still another object of the present invention to provide a movement guide device which does not damage the stage even if a temperature change occurs during transportation or use, and enables high-precision positioning without changing control characteristics and the like.

[0011]

To achieve the above object, a moving guide device according to the present invention comprises: a surface plate having a horizontal reference surface including a first direction and a second direction orthogonal to the first direction; A stage movable in the first and second directions above, a hydrostatic bearing for floating the stage above the reference surface and supporting the stage, and a single stage for guiding the stage along the first direction. , A first drive actuator for generating a driving force for moving the stage in the first direction, and a second drive actuator for generating a driving force for moving the stage in the second direction. The second drive actuator moves in the first direction together with the stage by driving the first drive actuator.

A preload mechanism for generating a preload between the stage and the reference surface may be provided. The first and second actuators may include a linear motor.

[0013]

1 to 5 show a schematic configuration of a first embodiment of the present invention. 1 is a perspective view, FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG. 1, FIG. 3 is a view taken on arrow B of FIG. 1, FIG. 4 is a view taken on arrow C of FIG. is there.

In FIG. 1, reference numeral 1 denotes a surface plate, the upper surface of which is a smooth reference surface. 1a is a notch for bearing maintenance, 4
Is a Y stage as a moving body, 5 is an X stage as a moving body, 2 is a fixed guide in the lateral direction (Y-axis direction) of the Y stage 4, and 3 (3a, 3b, 3c, 3d) is a porous static pressure. Air bearings, 3a for guiding the X stage 5 in the horizontal direction (Y-axis direction), 3b for guiding the X stage 5 in the vertical direction, 3C for guiding the Y stage 4 in the horizontal direction, and 3d for guiding the Y stage 4 in the vertical direction. are doing.

Reference numeral 4a denotes a horizontal and vertical static pressure air bearing mounting plate of the Y stage, and 4b denotes a lateral guide of the X stage 5. 4c is a drive actuator for the Y stage,
Reference numeral d denotes a connecting plate of the drive actuator 4c for the Y stage, which is connected to the static pressure air bearing mounting plate 4a. 5a is a moving plate of the X stage 5, 5b is a bearing mounting plate in the horizontal direction of the X stage 5, 5c is a bearing mounting plate in the vertical direction of the X stage 5, and 5d is a drive actuator of the X stage 5.
Reference numeral 6 denotes a preload magnet unit, which is disclosed in
For example, when a moving body is levitated by supplying a pressurized fluid to a hydrostatic bearing by a preload mechanism having a permanent magnet as a magnetic force means and yokes provided on both sides thereof as proposed in US Pat. The moving body is prevented from tilting due to variations in the characteristics of the bearing, and a constant posture is always maintained.

In this embodiment, the driving actuator 4
As c and 5d, for example, a linear motor, a hydraulic DC motor, or the like is used. As shown in FIG. 1, in the present embodiment, the Y stage 4 is floated from the surface plate 1 by supplying air to the static pressure air bearing 3, and the two drive actuators 4c
Thus, the fixed guide 2 is moved in the Y direction along the guide surface on the side surface. The X stage 5 is supplied to the static pressure air bearing 3 so as to float from the surface plate 1 in the same manner as the Y stage 4, and is moved in the X direction by the drive actuator 5c using the side surface of the Y stage 4 as a lateral guide. ing. At this time, the X stage 5 and the Y stage 4 are adjusted by the plurality of preload magnet units 6 so as to always have a constant posture.

The features of this embodiment are as follows: (a) Both the X stage and the Y stage are guided in the vertical direction from the surface plate, and even if the X stage or the Y stage moves, the moving load is applied to the other stage. The static posture is maintained well by preventing occurrence. (B) There is no coupling at all for the three components of vibration in the vertical direction (X direction in FIG. 1), vertical direction (Z direction in FIG. 1), and rolling (rotation about the Y axis in FIG. 1) of the Y stage. . (C) The pitching of the Y stage (rotation about the X axis in FIG. 1) is transmitted to only the X stage via the static air bearing 3a, thereby suppressing the coupling as much as possible. (D) Compared with the conventional moving guide device shown in FIG. 7, 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 4d 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, the driving points of the X stage and the Y stage substantially coincide with the center of gravity of the X stage and the Y stage in the height direction, thereby suppressing vibration during driving as much as possible. ing. (G) The length of the horizontal static pressure air bearing mounting plate 4a of the Y stage is matched with the length of the moving plate 5a of the X stage 5, thereby preventing the movable area from expanding. (H) The base 1, the fixed guide 2, the Y stage 4, and the X stage 5 can be made of different kinds of members having different thermal expansion coefficients. For example, the base 1 and the fixed guide 2 are made of a magnetic material for preloading the magnet, and the Y stage 4 and the X stage 5 are lightweight.
Materials such as ceramics can be used to increase rigidity. In this case, since there is only one fixed guide 2 and only one guide surface is used as a reference, there is no change in characteristics even if a temperature difference occurs. (I) By providing the notch 1a on the surface plate 1, even if foreign matter or the like is mixed in the hydrostatic bearing mounting plate 5d in the vertical direction of the X stage 5, the X stage 5 can be easily moved below the notch. Can be cleaned. (X) The lateral bearing mounting plate 5b of the X stage 5 is formed in a U-shape as shown in FIG. 2, so that the contact area of the members is increased and the reliability of the displacement of the fastening portion is improved. (R) By placing the fixed guide 2 sideways on the surface plate 1,
The fixed guide 2 does not shift sideways.

FIG. 6 is a perspective view of a second embodiment of the present invention. In this embodiment, the same members as those in the first embodiment are denoted by the same reference numerals. Referring to FIG.
Is fixed to the upper surface of the device by fixing means such as pinning and bonding (not shown).

According to this embodiment, (a) of the first embodiment will be described.
In addition to the effects of (1) to (4), (a) there is no need to process the fixed guide mounting surface (side surface) of the surface plate 1 of FIG. (B) Since the height of the fixed guide 2 can be reduced, sufficient rigidity can be maintained even if the thickness is reduced.

[0020]

According to the present invention, there is provided a movement guide device having a stage movable in first and second directions.
By guiding the stage in the first direction with a single fixed guide, even if the temperature changes during transportation or use, the stage will not be damaged, and the control characteristics will not change. It becomes possible. As a result, a movement guide device that enables highly accurate positioning is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

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

FIG. 3 is a view in the direction of arrow B in FIG. 1;

FIG. 4 is a view in the direction of arrow C in FIG. 1;

FIG. 5 is a rear view of the embodiment of FIG. 1;

FIG. 6 is a perspective view of a second embodiment of the present invention.

FIG. 7 is a perspective view of a conventional XY stage.

FIGS. 8A and 8B are explanatory diagrams of a problem of the related art.

FIG. 9 is an explanatory diagram of a vibration mode.

[Explanation of symbols]

1: surface plate, 1a: notch for bearing maintenance, 2: fixed guide, 3 (3a to 3d): hydrostatic air bearing, 4: Y stage, 4a: lateral and vertical bearing mounting plate, 4b: X stage Lateral guide, 4c: drive actuator, 4
d: communication plate, 5: X stage, 5a: moving plate, 5b: lateral bearing mounting plate, 5c: vertical bearing mounting plate, 5d: drive actuator, 6: magnet unit for preload.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-188241 (JP, A) JP-A-63-232912 (JP, A) JP-A-59-23890 (JP, A) 112541 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23Q 1/00-1/76 G12B 5/00 H01L 21/68

Claims (3)

(57) [Claims] A surface plate having a horizontal reference surface including a first direction and a second direction orthogonal to the first surface; a stage movable on the reference surface in the first and second directions; A static pressure bearing that floats and supports the stage on the reference surface, a single fixed guide for guiding the stage along the first direction, and a driving force for moving the stage in the first direction. Generating a first drive actuator and the stage
A second driving actuator for generating a driving force for moving in a direction, wherein the second driving actuator moves in the first direction together with the stage by driving the first driving actuator. 2. The movement guide device according to claim 1, further comprising a preload mechanism for generating a preload between the stage and the reference surface. 3. The movement guide device according to claim 1, wherein the first and second actuators include a linear motor.