JPS62187912A - Fine positioning device - Google Patents

Abstract

PURPOSE:To execute the fine positioning of a center rigid part by coupling the center rigid part with rigid parts on both the sides through respective flexible beam groups and bending said flexible beam groups. CONSTITUTION:Piezo-electric actuators 19a, 19b exist between the rigid parts 15a, 15b on both the sides and the center rigid part 15c and are fixed on projection parts 18a-18c projected from the rigid parts 15a-15c. The position of the center rigid part 15c is changed by impressing an optional voltage. The rigid parts 15a, 15b on both the sides are coupled with the center rigid part 15c through parallel flexible beam part 15c through parallel flexible beams 16a, 16a', 16b, 16b' and the change of the position of the center rigid part 15c deforms the parallel flexible beams 16a, 16a', 16b, 16b' and the change is detected by strain gauges 21a-21h.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fine position (a) determining device used in devices that require adjustment on the order of Bm, such as semiconductor manufacturing equipment and electron microscopes.

[Conventional technology]

In recent years, in various technical fields, there has been a demand for devices capable of fine displacement on the order of μm.

Typical examples are LSI (large scale integrated circuit) and very large scale integrated circuit (LSI).
semiconductor manufacturing equipment such as mask aligners and electron beam lithography equipment used in the manufacturing process.

These devices require fine positioning on the order of μm, and as the positioning accuracy improves, the degree of integration also increases, making it possible to manufacture high-performance products. Such fine positioning is not limited to the above-mentioned semiconductor devices, but also includes electronic caps and other devices. It is also necessary for 71 high magnification optical devices, etc., and by improving the n degree,
It will also greatly contribute to the development of advanced technologies such as biotechnology and space exploration.

Conventionally, such a fine positioning device has been described, for example, in "Mechanical Design" magazine, Vol. 27, No. 1 (January 1983 issue), No. 3.
C4 types as shown on pages 2 to 8 and 36 have been proposed. Among these, a type of fine positioning device using a parallel spring and a fine movement actuator is considered to be the most superior in that it does not require a particularly troublesome displacement reduction mechanism and has a simple configuration. This will be explained based on the diagram.

Figure 2F6 is a side view of a conventional fine positioning device. In the figure, 1 is a support base, 2a and 2b are plate-shaped parallel springs fixed parallel to each other on the support base 1, and 3 is a parallel spring 2a.
, 21) A highly rigid fine movement table fixed above. Reference numeral 4 denotes a rotary actuator e, which is suspended between the support stand l and the fine support table 3.

This single suction actuator 4 uses a compression element, an electromagnetic solenoid, etc., and by exciting this, a force is applied to the following table 3 in the X-axis direction of the coordinate axis shown in the figure.

Here, due to their structure, the parallel springs 2a and 2b have low rigidity in the Then, the parallel springs 2a and 2b are deflected, and the fine movement table 3 is displaced almost only in the X-axis direction, and displacement in other directions can be kept small. Therefore, if the object to be positioned is placed on the fine movement table 3, arbitrary minute displacements can be obtained in the xm direction depending on the degree of excitation of the fine movement actuator 4.

[Problems that the invention attempts to resolve] By the way, displacement in a positioning device often requires displacement in multiple directions, not just in one direction.
Furthermore, not only displacement parallel to a certain plane (translational displacement) but also rotational displacement around a certain axis is often required. However, the above conventional positioning device only works in one direction (
Only translational displacement in the X-axis direction is possible, and translational displacement in other directions is not possible. However, based on this positioning device, it is possible to stack them in two or three stages to obtain translational displacement in other directions (y-axis, zM force direction, ρ). Even if you configure
It is still not possible to obtain rotational displacement.

The present invention was made in view of these circumstances, and
The object is to provide a fine positioning device which can perform both translational displacement and rotational displacement with a simple structure, while eliminating the drawbacks of the prior art described above.

[Failure to solve the problem]

To achieve the above object, the present invention provides a rigid body part of the pond having a central rigid body part, opposing parts opposite to each side of this rigid body part, and a flexible body connecting the facing part and the central rigid body part. The present invention is characterized by comprising a group of beams, actuators that cause bending deformation in the flexible beams of each group of flexible beams, and a drive device that can independently drive each of these seven actuators.

[Effect]

When the drive device causes the flexible beams of each group of flexible beams to undergo the same bending deformation, the central rigid body portion is translated. On the other hand, when the drive device causes the flexible beams of each group of flexible beams to undergo different bending deformations, the central rigid body portion is rotationally displaced.

〔Example〕

Hereinafter, the present invention will be explained based on the illustrated embodiments.

FIG. 1 is a side view of a fine positioning device m according to a first embodiment of the present invention. In the figure 15 a * 15 b +1
Reference numerals 5c are rigid body parts located on the left, right, and center in the figure, respectively. The rigid body portion 15c serves as a fine movement table on which the object to be displaced is placed. 16 fi and 16 @' are plate-shaped parallel flexible beams that are formed integrally with the rigid body parts 15 a and 15 c, respectively, and are parallel to each other, and 16 b and 16 b' are respectively Rigid body part 1
It is a flat parallel flexible beam that is formed between 5b and 15c and is parallel to each other. 17a,
17b are parallel flexible beams 16a, 16a, respectively.
' and Koto row deflection beam 16b.

The through holes formed for integrally forming 16b' and each rigid body part are shown. 18a is a protrusion that protrudes from the rigid body part 15a to the through hole 17a, and 18c is a protrusion that protrudes from the rigid body part 15c to the through hole 17.
These protrusions 18 a +
18 cl overlap each other with a gap in the vertical direction of the figure. Similarly, 18b is a protrusion projecting from the rigid body part 15b to the through hole 17b, and 18 as is a rigid body part 15c.
These protrusions 18b and 18c+ are protrusions 18a and 18c that protrude from the through hole 17b.
, has a similar relationship.

19a is a piezoelectric actuator in which a piezoelectric element having a fixed pressure is laminated between a protrusion 18a and a protrusion 18c; 19b;
is the same pressure actuator as the piezoelectric actuator 19a fixed between the protrusion 18b and the protrusion 18C8. The piezoelectric actuator 19a is a parallel flexible beam 16
a, 16 Generate a force in the direction perpendicular to the plane of a',
The piezoelectric actuator 19b also causes a bending deformation in the parallel flexible beam 16b.

A force in the direction perpendicular to IK is generated on the plane of 16b', causing bending deformation in them. 20 is another rigid shoulder structure that rigidly connects the rigid body parts 15a and 15b to each other. 21a-21
h are parallel flexible beams 16a, 16a', 16b, 16b'
It is a strain gauge that detects the strain of a parallel flexible beam 1.
6 a, 16 a' and the connecting portions of the rigid body parts 15 a, 15 c, and the parallel flexible beams 16 b, 161)'
and the rigid body portions 15b and 15c. 22a is a power supply capable of applying an arbitrary iJt pressure to the piezoelectric actuator 19a, and 22b is a pressure source capable of applying an arbitrary voltage to the air actuator 19b.

In the above configuration, the rigid body portions 15a, 15c.

Parallel flexible beams 16a, 16a', protrusion 18a
, 18c+ and the piezoelectric actuator 19a, the beam displacement mechanism 23 a fJ'-beak, bursa j
4t, rigid body parts 15b, 15c, parallel flexible beam 16
b, 16 b', protruding fJ' l 8 b, 18
cs and the pressure center actuator 19b constitute the other parallel deflection beam displacement machine 231).

The parallel deflection beam displacement mechanism 23b (23a) then displaces the parallel deflection beam mf with respect to a plane perpendicular to the tenth circle formed by the parallel deflections 116a, 16a' (16b, 16b').
It has a plane symmetrical relationship with #23a (23b). K indicates a plane (reference plane) on which the parallel deflection beam displacement mechanisms 23a and 23b are symmetrical with respect to 1''A.

Next, the translational displacement operation in this embodiment will be explained with reference to FIG. FIG. 2 is a side view of the fine positioning device after the 72-ary displacement. Here, the coordinate axes are determined as shown in the figure (the y-axis generates a force f in the zII11 direction that is perpendicular to the plane of the paper. At this time, the displacement generated in one of the parallel deflection beam displacement mechanisms, for example, the parallel deflection beam displacement mechanism 23a) think about.

By applying the Kt pressure to the piezoelectric actuator 19a, the rigid body portion 15c is pressed in two axial directions by a force f. For this reason, the parallel flexible beams 16a, 16
B' undergoes bending deformation in the same way as the parallel springs 2a and 2b shown in Figure i6, and the rigid body portion 15c is displaced in the Z-axis direction. Similarly, the other parallel deflection beam displacement mechanism 23b also produces the same displacement by applying the voltage to the piezoelectric actuator 19bK.

As a result, the rigid body portion 15c generates a translational displacement ε only in the direction z i (B).

Also, as mentioned above, parallel flexible beams 16a, 16a'.

When the strain gauges 16b and 16b' are expanded and bent, compressive strain and expansion strain are generated in each of the strain gauges 21a to 21h due to their arrangement. Therefore, this strain is detected by the strain gauges 21a to 21h, and the piezoelectric actuator 19a is actuated based on the detected value.

If a so-called feedback control group is configured to control the voltage applied to 19b, even more accurate displacement C can be obtained. r41, each of the above strain gauges 21a~
The distortion detected by incorporating 21h into the bridge circuit is
The displacement ε extracted as g is exactly proportional to the strain),
This is sent to the ratio fAg section, and a difference signal between the two is calculated by comparing it with a signal corresponding to the image displacement of "b" and "L". Based on this difference signal, the pressure is set so that the difference No. 46 becomes O Control of the actuators 19a and 19b may be shifted.

Figure 3(a) is a circuit diagram of the bridge circuit, Figure 3(b)
) is an output diagram of the bridge circuit. When the average displacement shown in FIG. 2 occurs, the strain gauge 21a.

21 (l causes shrinkage and reduces its +>1 anti-value.

Conversely, the strain gauges 21b and 21c expand to increase their resistance value by [1]. Therefore, if a bridge circuit is constructed like a spider in Figure 3(a), the output according to '&11' will be
r? j IE V can be obtained. This output voltage V
The characteristics are shown in FIG. 3(b). As is clear from the figure, the output voltage V is proportional to the displacement amount ε. This detection voltage
By performing feedback control based on this information, it is possible to obtain extremely accurate translational displacement.

When the voltage applied to the piezoelectric actuators 19a and 19b is removed, each parallel deflection "41! '16af1
6a', 16b, and 16b' return to the state before deformation, and the displacement becomes O.

Next, the operation of rotational displacement in the actual shield will be explained with reference to FIG. FIG. 4 is a diagram of the fine position determining device after rotational displacement. Here, the coordinate axes are set to be 1$, the standard axis, and 1gej as shown in FIG. 'Et
The piezoelectric actuators 19,
A voltage E:a having a certain value is applied to the pressure forming actuator x9bKKt, and at the same time, a voltage ab having a value larger than the pressure Ea is applied to the pressure forming actuator x9bKKt. In this @ meeting, each parallel deflection beam displacement mechanism 23a, 2
3b, a translational displacement is generated by the above-mentioned operation, but the amount of displacement is larger in the parallel deflection Song displacement rock structure 23b and smaller in the parallel deflection beam displacement model $23a, so the rigid body portion 15c is , y +nt+ moving through its center
It is rotated around the four sides, producing a rotational displacement θ.

In addition, in FIG. 4, since the rotational displacement θ is exaggerated, it appears that bending force is applied to the piezoelectric actuators 19a and 19b, but the actual rotational displacement is 10
0=1000μrad'eii7&tea6(Qte,1'
): r', , l There is no problem with the strength of the actuators 19a, 19b.

Naturally, feedback control using a strain gauge is also possible for such rotational displacement (fM). This is shown in Figures 5(a) and (b). Figure 5(a) shows the circuit of the bridge circuit. Figure 5(b) shows the output lF!F characteristic diagram of the bridge circuit.At the rotational displacement shown in Fig. 4,
Bending deformation due to translation and deformation due to rotation occur simultaneously in each parallel flexible beam 16a, 16a', 16b, 16b'. So, in this case, does the bridge circuit undergo bending deformation due to translation? A bridge circuit must be used that can cancel out the deformation caused by rotation and extract only the deformation caused by rotation.

Bending deformation due to translation is caused by strain gauges 21e and 21h.
, and the extension leaves are equal. Contrary to the bending, deformation due to rotation causes the strain gauge 21e to contract and the strain gauge 21h to expand. Further, the bending deformation caused by the translation causes the strain gauges 21f and 21g to contract, whereas the deformation caused by the rotation causes the strain gauge 2 If to expand and the strain gauge 21g to contract.

Therefore, by configuring the bridge circuit as shown in FIG. 5(a) K, it is possible to obtain the output pressure V in accordance with the amount of rotational displacement θ. The output ``direct pressure V'' is proportional to the amount of rotational displacement as shown in FIG. 5(b). If feedback control is performed based on this detected voltage V, it is possible to obtain the desired accurate rotational displacement.

When the pressure applied to the piezoelectric actuators 19a, 19bK is removed, each parallel deflection i 16 a.

16a', 16b, 16b' return to the state before deformation,
The displacement becomes O.

Note that, contrary to the above explanation, the pressure iM, the actuator 1
It is clear that if the Ill pressure applied to the piezoelectric actuator b is greater than the Ill pressure applied to the piezoelectric actuator b, a rotational displacement in the opposite direction (clockwise in the figure) can be obtained. Also, the rotational displacement 110 is determined by the pressure actuator 19 g
, 191) has a value corresponding to the difference between the voltages Ea, Eb and J).

In this example, a power source that can apply any voltage is connected to each of the piezoelectric actuators in the parallel flexible beam displacement mechanism installed symmetrically, so that both translational displacement and rotational displacement can be obtained. . Further, since the entire structure can be constructed by simply forming a through hole in one rigid block, the structure is simple and manufacturing is easy.

Furthermore, since the piezoelectric actuator is mounted within the area formed by the rigid body part and the parallel flexible beam, the entire piezoelectric actuator has a small M
Vc +tl can be formed. In addition, the accuracy of position determination can be greatly improved by performing feedback control using a strong gear.

In addition, in the description of the above embodiment, the translational displacement in the uniaxial force direction and l
The rotational displacement around the axis is 1! Although the above-mentioned device has been described above, it is clear that if three of these devices are appropriately stacked, it is possible to obtain translational displacement in three axial directions and rotational displacement of 31 ull-.4 degrees.

Also, a strain gauge is not necessarily required. moreover,
The actuator is not limited to a piezoelectric actuator, and other actuators may be used.

〔Effect of the invention〕

As mentioned above, 5Vc, in this 5A example, 1ail of medium heat
Connect one body and the rigid bodies on both sides with multiple parallel flexible beams,
Since actuators for deforming these parallel flexible beams are provided on both sides and these actuators are driven independently, both translational displacement and dynamic displacement can be obtained with a simple structure of 17+i.

[Brief explanation of drawings]

Fig. 1 is a side view of a fine positioning device according to an embodiment of the present invention, Fig. 2 is a side view of a positioning device for M, advance displacement U; The circuit diagram of the bridge circuit using the strain gauge and its output characteristic diagram shown in Fig. 1, 'j;'a4 Fig.
1. A side view of the positioning device; FIGS. 5(a) and 5(b) are a circuit diagram of 160 bridge circuits using a strain gauge (not shown in FIG. 1) and its characteristic diagram; FIG. 6 is a side view of a conventional fine positioning device. It is. 15a, 15b, 15c...Rigid body part, 16a
, 16a'. 16b, 16b'...Parallel/l deflection beam, 19
a, 191) ・・・Piezoelectric actuator, 22t, 22b ・・・・Power supply agent Gui・Hira 戎 ；1；1 口（Outside 1）Fig. 1 Fig. 3

Claims (1)

[Claims] a rigid body part, another rigid body part having two opposing parts facing each other on both sides of the rigid body part, and a plurality of flexible beams arranged in parallel to each other that interconnect the rigid body part and each of the opposing parts. Two groups of flexible beams consisting of two groups of flexible beams, two actuators that cause bending deformation in each of the beams of these two groups of flexible beams, and a drive device that drives each of these two actuators independently. Features a fine positioning device.