JPH1048531A - Fine adjustable stage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the rigidity of a stage and to enhance the accuracy in by integrating the stage into one body constituted of a fixed part, a movable part and leaf springs and interposing a piezoelectric element between the fixed part and the movable part of the stage. SOLUTION: The stage 1 has an integrated structure constituted of the fixed part 2, the movable part 3 capable of relatively shifting in an X direction with reference to the fixed part 2 and four leaf springs 4 for elastically supporting both end parts of the movable part 3 in the X direction with reference to the fixed part 2. A space (m) for storing the piezoelectric element 6 is formed between the front side part 2b of the fixed part 2 in an Y direction and the movable part 3, and a pressure adjusting means, for example, a pressure adjusting screw 7 is screwed into the center of the front side part 2b. The tip part of the pressure adjusting screw 7 projects into the space (m) so as to press the piezoelectric element 6 arranged in the space (m) in the X direction, and then, the element 6 is pushed against the central part of the front side face of the movable part 3. The pressure adjusting screw 7 is adjusted so that it may press the piezoelectric element 6 against the movable part 3 and also the tip of the piezoelectric element 6 may come into contact with the movable part 3 by a prescribed pressure when the piezolectric element 6 is diminished as small as possible in size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine movement stage device used for a microscope fine movement stage, a semiconductor exposure stage, and the like.

[0002]

2. Description of the Related Art The structure shown in FIGS. 3 and 4, for example, is known as a fine movement stage. The stage 21 and the piezoelectric element mounting part 25 are fixed on the base 20 by screws 26 and 27, and the piezoelectric element 28 is clamped and fixed between the stage 21 and the piezoelectric element mounting part 25. The stage 21 is a flat metal plate and has a movable portion 23 between fixed portions 22 at both ends. A narrow groove 29a is formed along the boundary between the fixed portion 22 and the movable portion 23 in the X direction, and Y is formed from both ends of the groove 29a.
Grooves 29b narrow in the direction (the direction orthogonal to the X direction) are formed to penetrate in the stage plate thickness direction, respectively. The leaf springs 2 parallel to the Y direction are provided at the four corners of the movable portion 23 by the grooves 29b in the Y direction.
4 are formed.

A fixed portion 22 of a stage 21 is screwed to a base 20, and a movable portion 23 is elastically supported by a leaf spring 24 so as to be displaceable in the X direction. Movable part 23
The piezoelectric element 28 is arranged between the central part of the side surface in the Y direction and the piezoelectric element mounting part 25. The piezoelectric element 28 has, for example, a cylindrical shape, and one end in the axial direction is fixed to the piezoelectric element mounting component 25 by a screw or the like. The piezoelectric element 28 expands and contracts in the axial direction in accordance with the voltage applied to the piezoelectric element 28, and this displacement is directly transmitted to the movable portion 23 of the stage 21. A microscope (not shown) is supported by the movable part 23, and the piezoelectric element 28
The microscope moves together with the movable part 23 in accordance with the voltage applied to
Fine movement in the direction.

[0004]

When the piezoelectric element 28 provided between the piezoelectric element mounting part 25 on the base 20 and the stage 21 is most contracted, the tip of the piezoelectric element 28 is moved to the movable part 23 of the stage 21. The dimensions of each component are set so as to come into contact with a predetermined preload. However, the preload between the piezoelectric element 28 and the movable portion 23 varies due to a slight dimensional error or mounting error of each component.

Since the spring characteristics of the leaf springs 24 formed at the four corners of the movable portion 23 of the stage 21 are determined by the processing accuracy, it is difficult to set the spring characteristics of each leaf spring 24 to be the same. For this reason, due to variations in the spring characteristics of the leaf springs 24, yawing occurs when the movable portion 23 is displaced, and the positioning accuracy of the movable portion 23 may be reduced. Further, since the movable portion 23 is supported only by the leaf springs 24 at its four corners, it is vulnerable to disturbance such as vibration applied from the outside.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fine movement stage device in which the positioning accuracy of a stage movable portion is high and stable.

[0007]

According to the present invention, there is provided a fine movement stage apparatus comprising: a fixed portion; a movable portion capable of being displaced relative to the fixed portion;
And, a stage having an integral structure composed of a plurality of leaf springs elastically supporting both ends of the movable portion with respect to the fixed portion, and the movable portion with respect to the fixed portion interposed between the fixed portion and the movable portion of the stage. And a preload adjusting means mounted on a fixed portion of the stage and pressing the piezoelectric element in a predetermined direction to adjust the preload between the piezoelectric element and the movable portion.

[0008] The fixed portion of the stage is a portion that also serves as a base fixed to the mating device and a piezoelectric element mounting part. By also using the piezoelectric element mounting part, the rigidity of the stage itself is increased. In addition, by using the preload adjusting means to contact the piezoelectric element with the movable part of the stage with a predetermined preload, the displacement and response of the movable part to the displacement of the piezoelectric element are stabilized at a constant value, and the positioning accuracy of the movable part is improved. I do.

Further, the fine movement stage device according to the present invention has a pair of elastic members abutting on both ends of the movable portion opposite to the piezoelectric element, and is mounted on the fixed portion, and presses the respective elastic members so as to press the respective elastic members. Elastic force adjusting means for adjusting the urging force of the member against the movable portion.

[0010] By adjusting the urging force (elastic pressure) of the elastic member by the elastic force adjusting means, it is possible to suppress the variation in the spring characteristics of the leaf spring and prevent the occurrence of yawing.

Further, a vibration damping member may be interposed between the fixed portion and the central portion of the movable portion opposite to the piezoelectric element.

Since the vibration caused by the disturbance of the movable portion is absorbed by the damping member, the response of the movable portion to the displacement of the piezoelectric element is improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

The stage 1 in the fine movement stage device is
The fixed portion 2 includes a movable portion 3 that can be displaced relative to the fixed portion 2 in the X direction, and four leaf springs 4 that elastically support both ends of the movable portion 3 in the X direction with respect to the fixed portion 2. It has an integral structure. A groove 5a in the X direction on two sides 2a in the X direction,
A groove 5b extending from both ends of the groove 5a in the Y direction and a groove 5c adjacent in parallel with the groove 5b are formed to penetrate in the stage plate thickness direction. Close groove 5b and groove 5c
The leaf springs 4 are formed between them.

The front portion 2b of the fixed portion 2 in the Y direction and the movable portion 3
A space m for accommodating the piezoelectric element 6 is formed between them, and a preload adjusting means such as a preload adjusting screw 7 is screwed in the center of the front side 2b. The distal end of the preload adjusting screw 7 projects into the space m, presses the piezoelectric element 6 arranged in the space m in the X direction, and presses this against the center of the front side surface of the movable portion 3.

A gap n is formed between the rear side 2c of the fixed section 2 in the Y direction and the movable section 3, and a pair of elastic members, for example, disc springs 8 are installed at both ends of the gap n. A damping member, for example, a damping rubber 10 is installed at the center of n. Each of the pair of disc springs 8 is pressed in the X direction by a tip of an elastic force adjusting means, for example, a spring adjusting screw 9 screwed to the rear side 2 c of the fixed portion 2, and is provided at both ends of the rear side surface of the movable portion 3. It comes into contact with the vicinity of the leaf spring 4. The vibration damping rubber 10 is attached to the rear side 2
The distal end of the rubber pressure adjusting screw 11 screwed in the center of c is pressed in the X direction, and abuts the center of the rear side surface of the movable portion 3.

The preload adjusting screw 7 presses the piezoelectric element 6 against the movable section 3 and adjusts the tip of the piezoelectric element 6 to abut on the movable section 3 with a predetermined preload when the piezoelectric element 6 is compressed most. Is done. That is, the dimensional error of each part of the stage 1 itself, the variation in the spring characteristics of the leaf spring 4,
The variation of the preload between the piezoelectric element 6 and the movable portion 3 caused by the mounting error of each component to the component is suppressed by adjusting the preload adjusting screw 7. By adjusting the preload in this manner, the displacement amount and responsiveness of the movable portion 3 with respect to the displacement of the piezoelectric element 6 can be adjusted to predetermined values, and the positioning accuracy of the movable portion 3 is improved.

The adjustment of the preload between the piezoelectric element 6 and the movable part 3 is performed by operating the spring adjusting screw 9 of the disc spring 8 and the rubber pressure adjusting screw 11 of the damping rubber 10 to move the movable part 3 to the piezoelectric element 6. Alternatively, it is also possible to press the button. Preload adjustment for these three types of screws facilitates preload adjustment adapted to a plurality of types of stages 1 having different sizes.

When the spring characteristics of the leaf springs 4 formed at the four corners of the movable portion 3 are different, the movable portions 3 of the pair of disc springs 8 abut on both ends of the rear surface of the movable portion 3. By adjusting the urging force to the movable part 3 with the pair of spring adjusting screws 9,
It is possible to suppress variations in the spring characteristics at both end portions. By making the spring characteristics acting on the movable part 3 uniform, the effect of suppressing the occurrence of yawing when the movable part 3 is displaced is promoted, and the positioning accuracy of the movable part 3 is further improved.

The fixing part 2 is used as a base for mounting the stage 1 to a counterpart device, and the front side 2b of the fixing part 2 is used as a piezoelectric element mounting part.
The rigidity of the stage 1 having the fixed part 2 having an integral structure having both the base and the piezoelectric element mounting component is higher than that of the conventional configuration. Further, since the movable portion 3 is sandwiched between the piezoelectric element 6, the disc spring 8 and the vibration damping rubber 10 from both sides, it is resistant to external disturbances such as vibrations applied from the outside.
In particular, the damping rubber 10 absorbs the vibration due to the disturbance of the movable part 3 and exhibits an attenuation (vibration suppression) effect of attenuating the vibration at the time of displacement of the movable part 3 at an early stage. The response of the unit 3 is improved.

[0021]

According to the present invention, the stage is provided with a fixed portion,
The rigidity of the stage is improved compared to the conventional configuration because the integrated structure is composed of a movable part and a plurality of leaf springs, and a piezoelectric element is interposed between the fixed part and the movable part of the stage.
The positioning accuracy is improved. In addition, a preload adjusting means for adjusting the preload between the piezoelectric element and the movable part by pressing the piezoelectric element in a predetermined direction is provided, so that the preload of the piezoelectric element can be set to a predetermined value without being affected by a dimensional error of the stage or the like. And the positioning accuracy of the movable part can be highly stabilized.

A pair of elastic members abutting on both ends of the movable portion opposite to the piezoelectric element, and elastic force adjusting means for pressing the respective elastic members to adjust the urging force of each elastic member against the movable portion. With this arrangement, it is possible to correct variations in the spring characteristics of the leaf spring and prevent yawing of the movable portion.

Further, by interposing a vibration damping member between the fixed portion and the central portion of the movable portion opposite to the piezoelectric element, vibrations due to disturbance of the movable portion are absorbed by the vibration damping member. Responsiveness of the movable part to displacement of the element is improved.

[Brief description of the drawings]

FIG. 1 is a plan view including a partial cross section showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the device of FIG. 1 taken along line AA.

FIG. 3 is a plan view of a conventional fine movement stage device.

FIG. 4 is a cross-sectional view of the device of FIG. 3 taken along line BB.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stage 2 Fixed part 3 Movable part 4 Leaf spring 6 Piezoelectric element 7 Preload adjustment screw 8 Spring material (disc spring) 9 Spring adjustment screw 10 Damping rubber

Claims (3)

[Claims] A stage having an integral structure including a fixed part, a movable part capable of being relatively displaced with respect to the fixed part, and a plurality of leaf springs elastically supporting both ends of the movable part with respect to the fixed part; A piezoelectric element that is interposed between the fixed part and the movable part and presses the movable part in a predetermined direction against the fixed part, and is mounted on the fixed part of the stage and presses the piezoelectric element in a predetermined direction,
A fine movement stage device comprising: a preload adjusting means for adjusting a preload between a piezoelectric element and a movable portion. 2. A pair of elastic members abutting on both ends of the movable portion opposite to the piezoelectric element, and mounted on the fixed portion,
2. The fine movement stage device according to claim 1, further comprising: an elastic force adjusting unit that presses each elastic member to adjust an urging force of each elastic member against a movable portion. 3. The fine movement stage device according to claim 1, wherein a vibration damping member is interposed between a central portion of the movable portion opposite to the piezoelectric element and the fixed portion.