JPH0521697B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a minute displacement device for displacing and positioning a table with precision on the order of μm.

[Technical background of the invention and its problems] For example, when exposing semiconductor circuit elements, the table on which the wafer is placed is set at 1/3 to 1/1 of the pattern width.
It is required to perform positioning with an accuracy of 0, that is, an accuracy on the order of μm.

The positioning of such a table requires highly accurate positioning not only in the XY directions but also in all directions such as the Z direction, pitching, and yawing. In order to position such a table with high precision, there are known guide mechanisms for the table that use rollers or static pressure such as air. Another known method is to attach the table to a pair of parallel leaf springs and to elastically deform the leaf springs to displace the table.

However, in a guide mechanism that uses rollers or static pressure, the motion accuracy depends on the shape accuracy of the guide surface, so it not only takes a lot of effort to process the guide surface with high precision, but also the machining accuracy Limits arise. Furthermore, as shown in FIG. 5, in the guide mechanism using a leaf spring, when the table 1 is displaced in the a direction, the leaf spring 2 is bent and the table is also displaced in the b direction. 1 cannot be displaced with high precision only in a desired direction.

[Objective of the Invention] The present invention provides a micro-displacement device that can be manufactured easily without requiring time-consuming and high-precision machining, and that can be displaced with high precision only in the vertical and uniaxial directions. The purpose is to

[Summary of the Invention] A base, a plate-shaped support consisting of a pair of rigid bodies fixedly opposite to each other on the base, and a table attached to the upper ends of these supports in parallel to the base. , an actuator that is vertically telescopically inserted between the base and the table between the pair of supports, and the support has:
The supports are connected to the base and the table at the center, but are not connected to the base and the table at symmetrical positions. Spring grooves are provided in the left and right directions in the longitudinal direction, so that the supports are connected to the base and the table in multiple stages in the vertical direction and in the left and right directions. A spring section consisting of a plurality of arm sections formed in parallel is provided, and a communication groove is provided between the corresponding pair of spring grooves of the pair of left and right spring sections, and the communication groove allows the support body to connect to each left and right side. is divided into a pair of upper and lower divided pieces each having at least two arm portions, and both ends of the arm portions are formed into thin walled portions.These arm portions are rotatably provided through the thin walled portions. , an arm holding part that integrally holds a plurality of arm parts via a thin wall part is formed at both ends of the support body, and the arm parts on both sides of the upper piece and the arm part of the lower piece are
By acting as a parallel link and moving the table vertically while canceling out horizontal displacement between the two at symmetrical positions, the table can be moved with high precision only in the vertical and uniaxial direction without pitching or yawing. This allows for positioning.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. The minute displacement device shown in FIG. 1 includes a base 11. A pair of supports 12 each made of a uniformly tempered spring material is erected on both sides of the base 11 in the width direction. The support body 12 has a rectangular plate shape with a predetermined thickness, and spring portions 13 are formed symmetrically on both sides of the support body 12 in the width direction. The spring portion 13 is composed of a large number of arm portions 16 in which a large number of slit-like spring grooves 15 having circular holes 14 at both ends are formed in parallel and spaced apart from each other in the vertical direction. The portion located between the pair of spring grooves 15 of the support body 12, that is, both ends of the arm portion 16, is located in the circular hole 14.
It is formed in the thin wall portion 17 by. moreover,
The outermost sides of the support body 12 are arm holding parts 13a made of a rigid body.
Arm portions 16 arranged in parallel in multiple stages in the vertical direction are integrally held by 3 a via thin wall portions 17 . Therefore, the arm portion 16
is elastically rotatable about the thin wall portion 17 as a fulcrum. Furthermore, a pair of corresponding spring grooves 15 of the left and right spring portions 13 formed on the support body 12 are communicated with each other by a communication groove 18 . This communication groove 18
As a result, the portion of the support body 12 between the pair of spring portions 13 is divided into a lower piece 19 and an upper piece 21. In other words, the upper piece 21 has the left and right spring parts 13
The arm portion 16 of the support body 12 can be vertically displaced while elastically rotating, and the lower end surface of the lower piece 19 of the support body 12 is fixed to the base 11. Here, the arm portions 16 on both sides of the upper piece 21
There are at least one pair of arm portions 16 on both sides of the lower piece 19. And the upper piece 21
The arm portion 16 of the lower piece 19 and the arm portion 16 of the lower piece 19 are
Each side portion is a support body 12 having rigidity.
and the arm holding part 1 which also has rigidity.
3a, so that it acts as a parallel link. Accordingly, the upper piece 21 is provided so as to be slightly displaced in the vertical direction as the arm portions 16 move. In this case, if the arm part 16 is only on one side, the support body 12 will also be slightly displaced in the horizontal direction as the parallel link moves, but the arm parts 16 are provided in pairs at symmetrical positions on the left and right sides of the support body 12. Therefore, the horizontal displacement caused by the parallel link movement of the arm portion 16 is canceled out between the arms at symmetrical positions.
As a result, the upper piece 21 is displaced only in the vertical direction while keeping its parallelism with the base 11 constant.

A table 22 is fixed to the upper end surface of the upper piece 21 of the pair of supports 12 so that the lower surface of the table 22 is parallel to the upper surface of the base 11. At an intermediate position between the pair of supports 12, this table 22
An actuator 23 such as a piezo element is inserted between the base 11 and the base 11 . This actuator 23 is electrically connected to a control section (not shown), and expands and contracts in response to voltage from the control section. Therefore, when the actuator 23 is actuated, the table 22 elastically deforms the spring portion 13 of the support body 12 and is displaced in the vertical direction.

In a minute displacement device having such a structure, when the actuator 23 is not energized, the arm portion 16 of the spring portion 13 of the support body 12 does not elastically displace in the rotation direction as shown in FIG. 22 also has zero displacement in the upward direction. From this state, if a predetermined voltage is applied to the actuator 23 to extend it by the minute dimension l, the support 12
The spring portion 13 is deformed as shown in FIG. That is, when the table 22 is pushed up by the actuator 23, the upper piece 21 of the support body 12 communicates therewith. When the upper piece 21 rises, a plurality of arm parts 1 connected at one end to the upper piece 21
6 rotates in the direction shown by arrow a in the figure while elastically deforming the thin walled portions 17 at both ends. Further, at this time, the plurality of arm portions 16 whose one ends are connected to the lower piece 19 similarly rotate in the direction of arrow b, which is the opposite direction to arrow a, while elastically deforming the thin wall portions 17 at both ends. That is, when the table 22 is pushed up by the actuator 23, the arm portions 16 on both sides of the upper piece 21 and the arm portions 16 on both sides of the lower piece 19 move independently in parallel. In this case, since the arm parts 16 are provided in pairs at symmetrical positions on the support body 12, the minute displacement components in the horizontal direction due to the parallel link movement of the arm parts 16 are canceled out by the arm parts 16 in the symmetrical positions. As a result, the table 22 connected to the upper piece 21 is displaced only in the vertical direction while keeping its parallelism with the base 11 constant. Therefore, the table 22 is raised by the actuator 23 only in the vertical and uniaxial directions by the same dimension l as this extension dimension. In other words, the table 22 can be slightly displaced.

In this way, when the table 22 is slightly displaced in the vertical direction, the pair of arm parts 16 provided at left-right symmetrical positions on the support body 12 are each integrally connected by the arm holding part 13a, and the arm parts 16 are Since the arm portions 16 on both sides of the upper piece 21 and the arm portions 16 on the lower piece 19 are rotatably provided on the thin wall portions 17 provided at both ends as fulcrums,
act as a parallel link, and move parallel in the vertical direction while canceling out horizontal displacement between the two at symmetrical positions, so that the table 22 can be moved without pitching or yawing.
Positioning can be performed with high precision only in the vertical and uniaxial directions. Furthermore, forming the spring portion 12 on the support body 12 has the advantage that manufacturing becomes extremely easy, for example by using means such as wire cutting.

Note that the present invention is not limited to the above-mentioned embodiments; for example, the base and the support body or the support body and the table may be integrally formed.

[Effects of the Invention] As described above, the present invention includes a base, a plate-shaped support made of a pair of rigid bodies fixed oppositely to each other on the base, and a plate-like support made of a pair of rigid bodies fixed to the base on the base, and and an actuator that is vertically telescopically inserted between the base and the table between the pair of supports, and the support is located in the center of the table. At the left-right symmetrical positions of the support body which is connected to the base and the table, but not connected to the base and the table, spring grooves whose longitudinal direction is provided in the left-right direction are formed in multiple steps in the vertical direction and parallel to the left-right direction. A spring portion is provided with a plurality of arm portions, and a communication groove is provided between the corresponding pair of spring grooves of the pair of left and right spring portions, and the communication groove allows the support body to have at least It is divided into a pair of upper and lower divided pieces each having two arm parts, and both ends of the arm parts are formed into thin-walled parts. An arm holding part is formed at both ends to integrally hold a plurality of arms through a thin wall part, and the table is parallel to the base inserted between the table and the base between the pair of supports. The table can be minutely displaced only in the vertical and uniaxial directions with high precision without causing pitching or yawing while maintaining the state. Therefore, not only can the table be positioned without the need for highly accurate guide surfaces such as rollers or static pressure, but the spring part can also be formed by wire cutting, which simplifies production and reduces manufacturing costs. can be measured.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view showing an embodiment of the present invention, FIG. 2 is a side view of the spring before it is deformed, FIG. 3 is a side view of the spring after it is deformed, and FIG. FIG. 4 is an enlarged view of the thin portion, and FIG. 5 is an explanatory diagram of the conventional device. DESCRIPTION OF SYMBOLS 11... Base, 12... Support body, 13... Spring part, 13a... Arm holding part, 15... Spring groove, 16... Arm part, 22... Table.

Claims (1)

[Claims] 1 a base, a plate-shaped support consisting of a pair of rigid bodies fixed oppositely to each other on the base, a table attached to the upper ends of these supports in parallel to the base, and the pair an actuator that is vertically telescopically inserted between the base and the table between the supports;
The support body is connected to the base and the table at their center portions, and springs are provided at symmetrical positions of the support body that are not connected to the base and the table, with the longitudinal direction extending in the left-right direction. A spring portion is provided with a plurality of arm portions formed in multiple stages in the vertical direction and parallel to the left and right direction by grooves, and a communication groove is provided between the corresponding pair of spring grooves of the left and right pair and the spring portion. The supporting body is divided into a pair of upper and lower divided pieces each having at least two arm portions on each of the left and right sides by the communicating groove, and both ends of the arm portion are formed into thin-walled portions, and these arm portions are The support body is rotatably provided through a thin wall portion, and arm holding portions are formed at both ends of the support body to integrally hold the plurality of arm portions through the thin wall portion, and A micro-displacement device characterized in that the table is positioned with high accuracy in the vertical direction by moving the arm section in parallel in the vertical direction for each divided piece by the expansion and contraction drive of the actuator.