JPH0757457B2 - Moving table equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention is suitable for being incorporated as a sample stand of a microfabrication device such as a video disk or VLSI, and a feed position of a moving table. The present invention relates to a highly accurate moving table device.

(Prior Art) In a moving table device incorporated in a microfabrication device such as a video disk or VLSI, the table on which the sample is placed is generally moved in one direction at a constant speed or is positioned at a fixed position to be mounted on the sample. Has undergone fine processing. In this case, unless the table is moved smoothly over a long stroke and with high accuracy, there is a problem that the processing accuracy of the sample is significantly deteriorated.

However, in the moving table device having the conventional structure,
There are various problems as shown below and the reliability is poor.

For example, in many cases, as a moving table device conventionally used for such a purpose, as shown in FIG. 1, a rotation-controlled motor 1 is decelerated by gears 2 and 3, and a feed screw 5 is rotated. Since the feed screw 5 is axially supported by the bearing 4, the nut 6 moves in the axial direction. The movement of the nut 6 is connected to the moving table 8 by the connecting rod 7, and the guide 9 controls the movement of the moving table 8 supported by the base 10.

In this case, even if the motor 1 is controlled to rotate accurately, the gears 2 and 3, the bearing 4, the feed screw 5, which are transmission parts,
There is a drawback that a positioning error occurs due to the accuracy of processing and assembling the mechanical parts such as the nut 6. Further, there is a limit to the accuracy of processing and assembling these parts, and there is a problem in that the accuracy is deteriorated due to wear or the like. And
Since such a driving mechanism was directly connected to the moving table, the movement of the moving table is greatly affected by the accuracy of the driving mechanism, which is a major obstacle to fine processing requiring an accuracy of about 0.1 μm. Was there.

On the other hand, as shown in JP-A-49-10181,
A fine feed device using a laminated electrostrictive body and an electromagnet device has been proposed. This is an intermittent feed type fine motion feed device that combines expansion and contraction of a laminated electrostrictive body and fixing and opening of an electromagnet device.

Since this fine movement feed device is an intermittent feed device, it takes time to perform coarse movement feed of a long stroke. Therefore, there has been a problem that high-speed positioning cannot be achieved.

Further, even if the two examples shown above are used in combination, the table is a two-stage structure table in which the fine feed table device is placed on the coarse feed table device, and the height of the table device is increased and the thickness is reduced. Is not achieved.

(Problems to be Solved by the Invention) As described above, in a moving table device that uses mechanical parts such as a feed screw and a nut to convert the rotation of a motor into a linear feed, there is a limit in feed accuracy and Not suitable for processing,
Further, in the fine movement feeding device using the laminated electrostrictive body or the like, there are problems that long-stroke feeding cannot be performed and intermittent feeding causes difficulty in high-speed positioning.

The present invention has been made to solve these problems in consideration of the above circumstances, and an object of the present invention is to incorporate it in a microfabrication apparatus that has a high movement position accuracy of a table and can achieve a thin structure. It is to provide a suitable highly practical moving table device.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, in a moving table device of the present invention, the base surface serving as a stationary part and a guide provided on the base are used to form the base surface. A table provided for precision positioning provided movably in one axis direction parallel to the above, a motor that is fixed to the base side and generates a rotational driving force for moving the table, and a motor that is rotationally driven by the motor. A feed screw arranged in parallel with the moving direction of the table, a nut that meshes with the feed screw and moves linearly along the axial direction of the feed screw according to the rotation of the feed screw, and an expansion / contraction displacement direction of the table. One end side is fixed to the nut side and the other end side is fixed to the table side, respectively, in line with the direction, and the one side is fixed to the table as the nut moves. A fine movement displacement element utilizing a piezoelectric effect that can be moved, a detection means for detecting the moving position of the table, a detection signal from the detection means, and a target position signal of the table corresponding to the detection signal. Based on the comparison result, a signal for controlling the fine movement displacement element to be driven at the same time while driving the motor to reduce the position error during the movement of the table is calculated, and the fine movement is calculated. A control means for driving and controlling the displacement element is provided, and the height of the entire device is a sum of the height of the base, the height of the guide, and the height of the table.

(Operation) According to the present invention having such a configuration, it is possible to achieve high-precision positioning by compensating the feed accuracy of the feed screw with the high-precision feed accuracy of the fine movement displacement element utilizing the piezoelectric effect. Furthermore, since a table used for positioning is supported via a guide provided on the base, and a hybrid movement mechanism of a coarse movement mechanism and a fine movement mechanism can be configured without disposing a fine movement displacement element on the table. Since the height of the entire device can be suppressed to the sum of the height of the base, the guide provided on the base, and the height of the table supported through this guide, the height of the entire moving table device can be reduced. The thickness can be suppressed to a low level and thinning can be achieved (Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 2 shows a schematic configuration of an embodiment of the table device of the present invention. Rotation-controlled motor 11, gears 12, 13, bearing 14,
The feed screw 15, nut 16, and guide 19 are the same as those in the conventional example shown in FIG.

The characteristic structure of the present invention is that the fine displacement element 21 utilizing the piezoelectric effect is arranged in series between the connecting rod 17 and the movable table 18 movable with respect to the base 20.
More specifically, a connecting rod whose one end is fixed to the nut 16.
One end of a fine displacement element 21 is fixed to the other end of 17, and a movable table 18 is fixed to the other end of the fine displacement element 21.

With this configuration, the rotational force of the motor 11 is converted into a linear driving force by the feed screw 15 and the nut 16, the connecting rod 17 attached to the nut 16 is linearly moved, and the connecting rod 17 is attached to the connecting rod 17. Although the moving table 18 can be linearly moved in one direction, the moving table 18 can be driven by a fine movement displacement element 21 arranged in series between the connecting rod 17 and the moving table 18. ing.

Although the internal structure of the fine movement displacement element 21 utilizing the piezoelectric effect is omitted in the figure, the laminated piezoelectric elements are slightly displaced in response to an electric input, and expand and contract as a whole.

On the other hand, the detector 22 detects the axial position change of the moving table 18, the controller 23 compares it with the target value of the position, and the signal based on the difference between the detected value and the target value is used as an electric input for the fine displacement element. 21 is driven to correct and control the operation of the moving table 18, that is, the fine movement displacement element 21 is driven while the moving table 18 is moving to perform position correction control of the moving position of the moving table 18.

According to the moving table device of the present embodiment configured in this way, the feed accuracy of the drive mechanism composed of mechanical parts is sufficient if it is within the position correction capability by the fine movement displacement element 21 utilizing the piezoelectric effect. A long stroke drive mechanism can be easily created, and a fine displacement element can be used over the entire stroke.
Since it is possible to perform minute position correction by 21, it is possible to provide a highly reliable long stroke highly accurate moving table device that compensates the feed accuracy of 0.1 μm or less.

The present invention is not limited to the above embodiment. For example, as the drive mechanism, the components such as the motor 11, the gears 12, 13, the bearing 14, and the feed screw 15 are not limited to the shapes shown in the drawings, and other shapes having equivalent functions can be used. The measurement system such as a detector may be modified in various ways.

Further, the mounting structure of the fine movement displacement element 21 has been described as being arranged between the connecting rod 17 and the moving table 18 in the above description, but as shown concretely in FIG. Instead of directly attaching, a connecting member corresponding to a connecting rod may be projected from the moving table 18 and indirectly attached to the moving table. In the end, one end of the fine displacement element is fixed to the nut and the other end is fixed to the table. Any configuration will do.

Further, the moving table device of the present invention is a video disk,
It can also be implemented by incorporating it into equipment other than the microfabrication equipment for VLSI.

In short, the present invention can be variously modified and implemented without departing from the scope of the invention.

EFFECTS OF THE INVENTION As described in detail above, according to the present invention, highly accurate and reliable movement control of a table can be performed over a long stroke,
In addition, it is possible to provide a highly practical moving table device having a thin shape and a low device height.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a conventional moving table device, and FIG. 2 is a block diagram showing the structure of a moving table device according to an embodiment of the present invention. 11 …… motor, 12 …… gear, 13 …… gear, 14 …… bearing,
15 …… Feed screw, 16 …… Nut, 17 …… Connecting rod, 18 ……
Moving table, 19 ... Guide, 20 ... Base, 21 ... Fine displacement element, 22 ... Detector, 23 ... Controller

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-52-87584 (JP, A) JP-A-49-101812 (JP, A) JP-A-51-146357 (JP, A) JP-B 47- 7054 (JP, B1)

Claims (1)

[Claims] 1. A base which is a stationary part, a table which is provided for precision positioning by a guide provided on the base so as to be movable in one axial direction parallel to the base surface, and fixed to the base side. A motor that generates a rotational driving force for moving the table, a feed screw that is rotationally driven by the motor and that is arranged parallel to the moving direction of the table, and a feed screw that meshes with the feed screw to rotate the feed screw. Therefore, a nut that linearly moves along the axial direction of the feed screw, and the expansion / contraction displacement direction is made to coincide with the movement direction of the table, and one end side thereof is fixed to the nut side and the other end side thereof is fixed to the table side. A fine movement displacement element utilizing a piezoelectric effect, which is movable integrally with the table in accordance with movement of the table, and detection for detecting a position during movement with the table. And a detection signal from the detection means and a target position signal of the table corresponding to the detection signal, and based on the comparison result, the fine displacement element is simultaneously driven during driving of the motor. And a control means for driving and controlling the fine movement displacement element by calculating a signal for controlling the position error during movement of the table, wherein the height of the entire apparatus is the same as the height of the base. A moving table device characterized in that the height of the guide is the sum of the heights of the table.