JPH0735987A - Z-axis fine adjusting mechanism - Google Patents

Abstract

PURPOSE:To obtain a thin and inexpensive fine adjusting Z stage by converting the displacement of an actuator from a rotary motion to linear motion by a mechanism having an elastic hinge. CONSTITUTION:The one side of a hinge block 4 1s fixed to a piezoelectric actuator 8, and the other side of the hinge block 4 is fixed on a base 1. A lever 5 is linked with the hinge block 4 so as to interpose the block 4, and also linked with a stage 2 and the base 1. Stroke from the actuator 8 extended in a horizontal direction with a reference block 3 as reference is transmitted to the hinge plate 4, and the hinge plate 4 is rotated with an elastic hinge supporting point 24 as a supporting point. The lever 5 is rotated with an elastic hinge supporting point 26 as a supporting point by rotational force transmitted from the hinge plate 4. The rotational force is converted into the stroke in an up-and-down direction (Z-axis direction) on the center side of the stage 2. The stroke of displacement is enlarged in the ratio of a distance between the supporting points 23 and 24 to a distance between the supporting points 25 and 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stage mechanism section of a microscopic dimension measuring apparatus using a microscope.

[0002]

2. Description of the Related Art A device for measuring the shape and size of electronic devices such as semiconductors and magnetic heads requires a fine-movement Z-axis drive mechanism for an autofocus microscope, which performs positioning with high precision and has a high resolution and a stroke of about 100 μm. Is. Such a Z-axis fine movement mechanism is generally used in combination with an X, Y stage or a rotary stage. An example of the conventional Z-axis fine movement mechanism will be described with reference to FIGS. 6 and 7. FIG. 6 is a plan view of a conventional Z fine movement mechanism, and FIG. 7 is D of FIG.
FIG. 6D is a cross-sectional view showing a reference block 12 fixed to the base 9, and a lever-like hinge plate 11 having three elastic hinges fixed to the reference block 12;
As shown in FIGS. 6 and 7, there are 3 places 12 on the base 9.
It is arranged and fixed at 0 ° pitch. The column 16 is fixed to the base 9, and the actuator plate 15 is fixed. The actuator base 13 is connected to one end of the hinge plate 11 with a spacer 14 in between. The tension spring 10 is attached in order to apply a preload to the piezoelectric actuator 18 and prevent backlash.
The piezoelectric actuator 18 is arranged and fixed on the Z-axis, that is, vertically at the center of the stage 27. When a voltage is applied to the piezoelectric actuator 18, the piezoelectric actuator 18 has its upper part fixed, so that it is lower, that is, the piezoelectric actuator 18. It extends in the direction of pushing down the base 13. At this time, the hinge plate 11 performs a rotational movement with the elastic hinge fulcrum 19 as a fulcrum. The elastic hinge 20 converts a downward moving linear motion into a rotary motion, and the elastic hinge 21 converts a rotational motion into an upward linear motion without backlash, friction and wear. The stroke of the piezoelectric actuator 18 starts from the elastic hinge fulcrum 19,
Due to the relationship of a multiple of the distance to the elastic hinge 20 and the distance to the elastic hinge 21, that is, the lever ratio (4: 1), the magnification is expanded to about 4 times and converted upward. Also, the hinge plate 11
Has a wide width and is arranged at three 120 ° pitches.
In the up-down direction, high precision straight guidance accuracy can be obtained.

[0003]

In the above-mentioned prior art,
Since the actuators are arranged vertically, the height of the stage itself is large, and the number of parts is large and the cost is high. It is an object of the present invention to eliminate these drawbacks, to make the device thin, low-priced, and to the same level as the accuracy of conventional stages.

[0004]

In order to achieve the above object, the present invention has a structure in which an actuator is arranged in parallel with a stage and the displacement of the actuator is converted in the Z-axis direction of the stage to obtain a stroke. did. In addition, in order to obtain high straightness accuracy, a mechanism is adopted in which the table and the base are connected by four parallel leaf spring wide blocks symmetrically arranged on a diagonal line to restrict the straight movement.

[0005]

The operation of the present invention will be described. The displacement of the actuator is converted from the rotational movement to the linear movement by the mechanism having the elastic hinge, and the action of the four parallel leaf springs symmetrically arranged on the Z axis, that is, the diagonal line. This makes it possible to obtain a vertical stroke with high straightness. Therefore, it is possible to obtain a low-priced fine movement Z stage which is thin and has a small number of parts.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
This will be described with reference to FIGS. 4 and 5. 1 is a plan view of an embodiment of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG.
5 is a sectional view taken along line BB of FIG. 4, FIG. 4 is a sectional view taken along line CC of FIG. 1, and FIG. 5 is a sectional view taken along line EE of FIG. 1 is the base, 2 is the stage,
Reference numeral 3 is a reference block serving as a displacement reference of the piezoelectric actuator, and 4 is a hinge block, one of which is fixed to the piezoelectric actuator and the other of which is fixed to the base 1 to form three elastic hinges. Reference numeral 5 is a lever for converting the rotational movement into a vertical linear movement.
It is connected to the hinge block 4 with a structure of sandwiching, and also connected to the stage 2 and the base 1. 6
a, 6b, 6c and 6d are arranged symmetrically on the diagonal line in order to make the linear motion from the lever 5 highly accurate with respect to the base 1, that is, high straight guide accuracy and high vertical accuracy. Are connected. Also, by having four elastic hinges, it has a parallel leaf spring structure.
It can act with a small force in the vertical direction, and since it is wide, it also secures horizontal rigidity. 7a and 7b are for applying preload to the piezoelectric actuator to eliminate backlash in the stroke. Arranged symmetrically,
The reference block 3 and the hinge plate 4 are pulled. A stroke from the piezoelectric actuator 8 extending in the horizontal direction with reference to the reference block 3 is transmitted to the hinge plate 4 and rotates about the elastic hinge fulcrum 24.
The elastic hinge 23 is formed in order to transmit the stroke efficiently. Hinge lever 5 is hinge plate 4
Since it is connected to the hinge plate 4, it is rotated about the elastic hinge fulcrum 26 by the rotational force transmitted from the hinge plate 4,
Converted to vertical strokes on the center side of the stage. The elastic hinge 25 is formed so that a vertical stroke can be efficiently obtained. Further, the horizontal displacement generated in the hinge lever 5 at this time is absorbed by the elastic hinge 25. The displacement stroke is the elastic hinge fulcrum 2
It is enlarged by the ratio of the distance of 3 and 24 to the distance of 25 and 26.
Here, a material having high rigidity is suitable for the hinge plate 4, the hinge lever 5, and the guide block 6 each having an elastic hinge, for example, carbon steel is excellent. With such a material, the hinge portion can be formed to have a thickness of about 0.5 mm. A piezoelectric element is excellent as the actuator 8, and in this embodiment, the piezoelectric actuator 8 is used.
When the length is 36 mm, the displacement is 0
When a displacement of 30 μm occurs at V to 100 V and the expansion ratio that can be leveraged 5 is set to 4: 1, the Z-axis generation stroke is 1
It was 20 μm. Furthermore, by controlling the applied voltage, displacement in at least 0.01 μm steps is possible.

[0007]

As described above, according to the present invention, the stage mechanism portion can be manufactured with a height of about 1/3 of the height of the conventional mechanism portion, and the number of parts is reduced to about half. Therefore, low price can be realized.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a sectional view of an embodiment of the present invention.

FIG. 3 is a sectional view of an embodiment of the present invention.

FIG. 4 is a sectional view of an embodiment of the present invention.

FIG. 5 is a sectional view of an embodiment of the present invention.

FIG. 6 is a plan view of a conventional example.

FIG. 7 is a sectional view of a conventional example.

[Explanation of symbols]

 1 Base 2 Stage 3 Reference Block 4 Hinge Block 5 Lever 6 Guide Block 7, 7'Tension Spring 8 Actuator 22, 23, 24, 25, 26 Elastic Hinge

Claims (1)

[Claims] 1. A reference block fixed to a base and three elastic hinges are used to convert a linear motion of a piezoelectric actuator into a rotary motion and to expand a stroke of the piezoelectric actuator, thereby increasing a Z-axis direction of an upper stage. The stage and the base are connected by a hinge block having a lever function for converting into a motion of the stage, a preload spring provided on the piezoelectric actuator, and four parallel leaf spring wide blocks symmetrically arranged on the diagonal line of the stage. A Z-axis fine movement mechanism having a mechanism for restricting straight movement.