JP2007090501A - Positioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly accurate positioning device. <P>SOLUTION: A bolt 19, an actuator 21, and an intermediate table 9 are electrically insulated by insulating bushes 20-1, 20-2, and the actuator 21, and a metal block 23 of a main table 12 are electrically insulated by an insulating plate 24, whereby electric noise is restrained from being propagated to the device body. Two displacement detecting sensors 30-1, 30-2 disposed in symmetric positions about the X-axis respectively detect the displacement of the distance between the intermediate table 9 and the main table 10, whereby the distance between the intermediate table and the main table is accurately measured. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a positioning device, and more particularly to a positioning device that moves a table in a predetermined direction for positioning.

  Positioning devices used for precision processing devices, precision inspection devices, and the like are required to have high precision positioning. For this reason, a coarse movement mechanism having a large movable range and a fine movement mechanism having a small movable range are provided.

The following Patent Document 1 discloses a configuration in which an intermediate table 25 that enables coarse movement positioning and a connected main table A23 and main table B24 that allow fine movement positioning so as to sandwich the intermediate table 25 are disclosed. Has been. According to this, the main table A23 and the main table B24 can be finely moved and positioned by the extension of the piazo actuator 17 provided in the intermediate table 25.
JP 2004-192588 A

  However, when a conventional positioning device is used as a work table such as an electron beam drawing device, electrical noise generated when a driving voltage is applied to a piazo actuator (piezoelectric actuator) is propagated to the device body. There was a problem that positioning accuracy was lowered due to an error in the measurement system. In particular, such a problem is likely to occur when a piezo actuator having a piezoelectric element housed in a metal case is used for grounding.

  Further, since the piazo actuator applies a driving force to one point of the main table, there is a possibility that the main table tilts during fine movement positioning operation. Conventionally, the displacement of the distance between the intermediate table and the main table is detected by a single displacement detection sensor arranged at a position away from the piazo actuator, resulting in a measurement error of the amount of displacement and a decrease in positioning accuracy. There was a problem to do.

  Therefore, a main object of the present invention is to provide a positioning device that enables highly accurate positioning.

  A positioning device according to the present invention is a positioning device for positioning by moving a table in a predetermined direction, an intermediate table provided so as to be movable in a predetermined direction, a driving means for moving the intermediate table, and an intermediate table A main table movably provided in a predetermined direction, and an actuator provided between the intermediate table and the main table and extending and contracting in a predetermined direction to move the position of the main table relative to the intermediate table. By electrically interposing the first and second insulating members between the actuator and the intermediate table and between the actuator and the main table, respectively, the actuator and the intermediate table and the actuator and the main table are electrically insulated. It is characterized by that.

  Preferably, the first and second insulating members are made of ceramic.

  Preferably, the main table is a first sub main table provided on one side of the intermediate table, and a second sub main table provided on the other side of the intermediate table and connected to the first sub main table. The positioning device further includes a compression spring provided between the first sub main table and the intermediate table, and the actuator is provided between the intermediate table and the second sub main table. The actuator is always pressed against the second sub-main table through the second insulating member by the extending action of.

  Preferably, the second insulating member is fixed to the second sub main table, and a surface against which the actuator is pressed has a spherical shape.

  Another positioning device according to the present invention is a positioning device for positioning by moving a table in a predetermined axial direction, an intermediate table provided so as to be movable in a predetermined axial direction, and driving means for moving the intermediate table And a main table provided so as to be movable in a predetermined axial direction with respect to the intermediate table, and provided between the intermediate table and the main table and extending and contracting in a predetermined axial direction to position the main table relative to the intermediate table. Actuators to be moved, first and second sensors respectively provided on an intermediate table or a main table, arranged on both sides of a predetermined axis, for detecting a distance between the intermediate table and the main table, and first and first Calculation means for calculating a distance between the intermediate table and the main table based on the detection result of the second sensor. And wherein the door.

  Preferably, the first and second sensors are arranged at symmetrical positions with respect to a predetermined axis, and the calculating means calculates an average value of detection results of the first and second sensors. .

  Preferably, the actuator is a piezoelectric actuator using a piezoelectric material.

  Preferably, the actuator is an electromagnetic actuator using a magnetic material.

  In the positioning device according to the present invention, an intermediate table provided to be movable in a predetermined direction, a driving means for moving the intermediate table, a main table provided to be movable in a predetermined direction with respect to the intermediate table, An actuator provided between the intermediate table and the main table and extending and contracting in a predetermined direction to move the position of the main table relative to the intermediate table, and between the actuator and the intermediate table and between the actuator and the main table In addition, the actuator and the intermediate table, and the actuator and the main table are electrically insulated by interposing the first and second insulating members, respectively. Therefore, electrical noise generated when a drive voltage is applied to the actuator can be prevented from propagating to the apparatus body, and high-accuracy positioning is possible.

  In another positioning apparatus according to the present invention, an intermediate table provided to be movable in a predetermined axial direction, a driving means for moving the intermediate table, and a movable means provided in a predetermined axial direction with respect to the intermediate table are provided. A main table, an actuator provided between the intermediate table and the main table, and extending and contracting in a predetermined axial direction to move the position of the main table relative to the intermediate table; Between the intermediate table and the main table based on the detection results of the first and second sensors and the first and second sensors that are disposed on both sides of the first and second sensors for detecting the distance between the intermediate table and the main table. And calculating means for calculating the distance. Therefore, even when the main table is slightly tilted with respect to a predetermined axis during the positioning operation, the distance between the intermediate table and the main table can be accurately measured, and high-accuracy positioning is possible.

  1 and 2 are a plan view and a side view showing a configuration of a positioning device according to an embodiment of the present invention. 1 and 2, a motor 1 is fixed to a base 3 of this positioning device via a bracket 2. The motor 1 moves the ball screw 5 connected via the coupling 4 in the X-axis direction. The ball screw 5 is supported by support units 6 and 7 fixed on the base 3.

  A nut 8 formed integrally with the intermediate table 9 is fitted into the ball screw 5 and fixed. On the left and right sides of the intermediate table 9, main tables 10 and 11 connected by connecting bars 12 and 13 are provided. A slight gap is provided so that the intermediate table 9 and the connecting bars 12 and 13 do not contact each other.

  On the base 3, guide rails 15_1 and 15_2 are provided via spacers 14_1 and 14_2. The main table 10 is fixed on a guide block 16_1 movably provided on the guide rail 15_1 and a guide block 16_2 movably provided on the guide rail 15_2. The intermediate table 9 is fixed on a guide block 17_1 movably provided on the guide rail 15_1 and a guide block 17_2 movably provided on the guide rail 15_2. Further, the main table 11 is fixed on a guide block 18_1 movably provided on the guide rail 15_1 and a guide block 18_2 movably provided on the guide rail 15_2.

  Bolts 19 are provided on the X axis inside the intermediate table 9, and the bolts 19 are supported by two insulating bushes 20 </ b> _ <b> 1 and 20 </ b> _ <b> 2 fixed to the intermediate table 9. An extendable actuator 21 is fixed to a screw tip portion of the bolt 19. Further, an adjustment screw 22 is inserted on the X axis inside the main table 10, and a metal block 23 is fixed to a screw tip portion of the adjustment screw 22. An insulating plate 24 is fixed to the side surface of the metal block 23, and the actuator 21 is pressed against the insulating plate 24.

  Inside the main table 11, compression springs 25_1 and 25_2, head portions 26_1 and 26_2, and adjustment screws 27_1 and 27_2 are provided at positions symmetrical to the X axis. The adjustment screws 27_1 and 27_2 are respectively inserted from screw holes of the fixing plate 28 fixed to the side surface of the main table 11, and load applied to one end of the compression springs 25_1 and 25_2 via the head portions 26_1 and 26_2. Can be adjusted. The other ends of the compression springs 25_1 and 25_2 are both fixed to the intermediate table 9, and the actuator 21 is always pressed against the insulating plate 24 of the main table 10 by the expansion action of the compression springs 25_1 and 25_2. .

  The motor 1 and the ball screw 5 constitute a coarse movement mechanism that moves the intermediate table 9 over a wide range, and the actuator 21 constitutes a fine movement mechanism that moves the positions of the main tables 10 and 11 relative to the intermediate table 9 within a narrow range. . A gap is provided between the intermediate table 9 and the main tables 10 and 11, and the main tables 10 and 11 can be moved minutely by driving the actuator 21 to extend and contract by a drive device (not shown). . Further, the height of the intermediate table 9 is slightly lower than the height of the main tables 10 and 11 so that the load 29 placed on the main tables 10 and 11 does not come into contact with the intermediate table 9. As the actuator 21, for example, a piezoelectric actuator using a piezoelectric material that expands and contracts according to an applied voltage, or an electromagnetic actuator using a magnetic material such as an electromagnet is used.

  FIG. 3 is a partially enlarged view showing a main part of the positioning device shown in FIG. Referring to FIG. 3, bolt 19 and actuator 21 are fixed to intermediate table 9 via ceramic insulating bushes 20_1 and 20_2. Bolt 19, actuator 21 and intermediate table 9 are connected to insulating bushes 20_1 and 20. It is electrically insulated by 20_2. The actuator 21 and the metal block 23 of the main table 12 are electrically insulated by a ceramic insulating plate 24.

  In order to prevent a decrease in positioning accuracy, it is desirable to use a material having a large elastic coefficient, such as ceramic or glass, for the insulating bushes 20_1 and 20_2 and the insulating plate 24. These materials are also suitable for positioning devices that are used in a vacuum environment, such as an electron beam drawing apparatus, because the amount of outgas that contaminates the environment in vacuum is small.

  With the configuration as described above, it is possible to suppress electrical noise generated when a drive voltage is applied to the actuator 21 from being propagated to the apparatus main body. Therefore, the conventional problem that an error occurs in the position measurement system is solved, and high-accuracy positioning is possible.

  Returning to FIG. 1, the intermediate table 9 includes two displacement detection sensors 30_1 and 30_2 for detecting the displacement of the distance between the intermediate table 9 and the main table 10 by the fixed blocks 31_1 and 31_2, respectively. It is fixed. The two displacement detection sensors 30_1 and 30_2 are arranged at positions symmetrical with respect to the X axis.

  Furthermore, calculation means (not shown) for calculating the average value of the output values of these two displacement detection sensors 30_1 and 30_2 is provided. Then, the main tables 10 and 11 are slightly moved with respect to the intermediate table 9 by driving the actuator 21 to extend and contract by a drive device (not shown) based on the calculation result by the calculation means.

  Thus, by taking the average value of the output values of the two displacement detection sensors 30_1 and 30_2, even when the main table 10 is slightly tilted with respect to the X axis during the positioning operation, the intermediate table 9 and the main table 10 It becomes possible to accurately measure the displacement of the distance between them. By feeding back the output values of the displacement detection sensors 30_1 and 30_2 to the driving device of the actuator 21, positioning with high accuracy becomes possible.

  Further, by comparing the output values of the displacement detection sensors 30_1 and 30_2, the magnitude of the inclination of the main table 10 with respect to the X axis is calculated, and the positioning error due to the inclination of the main table 10 is corrected using the calculation result. It is also possible to do. For example, a rotation table for tilt correction may be mounted on the main tables 10 and 11 and a load may be placed on the rotation table. In this case, it is possible to correct the inclination of the main table 10 by rotating the rotation table by the calculated inclination of the main table 10. Further, in the case of an electron beam drawing apparatus, the direction of the electron beam is corrected by changing the electric field that controls the trajectory of the electron beam radiated to the loaded substrate by the calculated inclination of the main table 10. May be. In this way, the positioning accuracy is further improved by correcting the positioning error due to the tilt of the main table 10.

  As the displacement detection sensors 30_1 and 30_2, for example, capacitive sensors may be used, or other arbitrary sensors may be used. For example, a non-contact type sensor such as a laser interferometer or an eddy type displacement meter may be used. Further, a contact type sensor such as a stylus displacement meter may be used. In the case of an electron beam drawing apparatus, a capacitive sensor or a laser interferometer that does not affect the electron beam trajectory is suitable.

  Although the case where the displacement detection sensors 30_1 and 30_2 are provided in the intermediate table 9 is shown here, the displacement detection sensors 30_1 and 30_2 may be provided in the main table 10.

  FIG. 4 is a diagram showing a modified example of this embodiment, and is a diagram to be compared with FIG. Referring to FIG. 4, the difference from FIG. 3 is that insulating plate 24 is replaced with insulating sphere 32. A recess for fitting the insulating sphere 32 is formed on the side surface of the metal block 23, and the insulating sphere 32 is fixed to the side surface of the metal block 23.

  Thus, by adopting a configuration in which the central portion of the side surface of the actuator 21 is pressed against the spherical surface of the insulating sphere 32, the bending moment is prevented from acting on the actuator 21, and the actuator 21 is prevented from being damaged and has a long life. Figured. In order to prevent a decrease in positioning accuracy, it is desirable to use a material having a large elastic coefficient such as ceramic for the insulating sphere 32.

  FIG. 5 is a diagram showing another modification of the embodiment and is a diagram contrasted with FIG. Referring to FIG. 5, the difference from FIG. 3 is that insulating plate 24 is replaced with insulating hemisphere 33. The insulating hemisphere 33 is fixed to the side surface of the metal block 23.

  In this way, by adopting a configuration in which the central portion of the side surface of the actuator 21 is pressed against the spherical surface of the insulating hemisphere 33, the bending moment is prevented from acting on the actuator 21, thereby preventing the actuator 21 from being damaged and extending its life. Figured. In order to prevent a decrease in positioning accuracy, it is desirable to use a material having a large elastic coefficient such as ceramic for the insulating hemisphere 33.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a top view which shows the structure of the positioning device by one Embodiment of this invention. It is a side view which shows the structure of the positioning device by one Embodiment of this invention. It is the elements on larger scale which show the principal part of the positioning device shown in FIG. It is a figure which shows the example of a change of this one embodiment. It is a figure which shows the other example of a change of this one embodiment.

Explanation of symbols

  1 motor, 2 bracket, 3 base, 4 coupling, 5 ball screw, 6, 7 support unit, 8 nut, 9 intermediate table, 10, 11 main table, 12, 13 connecting bar, 14_1, 14_2 spacer, 15_1, 15_2 guide Rail, 16_1, 16_2, 17_1, 17_2, 18_1, 18_2 Guide block, 19 bolt, 20_1, 20_2 Insulating bush, 21 Actuator, 22, 27_1, 27_2 Adjustment screw, 23 Metal block, 24 Insulating plate, 25_1, 25_2 Compression spring, 26_1, 26_2 Head part, 28 Fixed plate, 29 Load, 30_1, 30_2 Displacement detection sensor, 31_1, 31_2 Fixed block, 32 Insulating sphere, 33 Insulating hemisphere.

Claims (8)

A positioning device that moves and positions a table in a predetermined direction,
An intermediate table provided movably in the predetermined direction;
Drive means for moving the intermediate table;
A main table provided to be movable in the predetermined direction with respect to the intermediate table;
An actuator that is provided between the intermediate table and the main table and extends and contracts in the predetermined direction to move the position of the main table relative to the intermediate table;
By interposing the first and second insulating members between the actuator and the intermediate table and between the actuator and the main table, the actuator and the intermediate table, and the actuator and the main table, respectively. A positioning device characterized in that the table is electrically insulated.   The positioning device according to claim 1, wherein the first and second insulating members are made of ceramic. The main table is
A first sub-main table provided on one side of the intermediate table;
A second sub main table provided on the other side of the intermediate table and connected to the first sub main table;
The positioning device further includes a compression spring provided between the first sub main table and the intermediate table,
The actuator is provided between the intermediate table and the second sub main table, and the actuator is always attached to the second sub main table via the second insulating member by the extension action of the compression spring. The positioning device according to claim 1, wherein the positioning device is pressed against the positioning device.   The positioning device according to claim 3, wherein the second insulating member is fixed to the second sub main table, and a surface against which the actuator is pressed has a spherical shape. A positioning device that moves and positions a table in a predetermined axial direction,
An intermediate table provided movably in the predetermined axial direction;
Drive means for moving the intermediate table;
A main table provided to be movable in the predetermined axial direction with respect to the intermediate table;
An actuator that is provided between the intermediate table and the main table, and expands and contracts in the predetermined axial direction to move the position of the main table relative to the intermediate table;
A first sensor and a second sensor, which are respectively provided on the intermediate table or the main table, are arranged on both sides of the predetermined axis, and detect a distance between the intermediate table and the main table;
A positioning apparatus comprising: a calculating unit that calculates a distance between the intermediate table and the main table based on detection results of the first and second sensors. The first and second sensors are arranged at symmetrical positions with respect to the predetermined axis,
The positioning device according to claim 5, wherein the calculating unit calculates an average value of detection results of the first and second sensors.   The positioning device according to claim 1, wherein the actuator is a piezoelectric actuator using a piezoelectric material.   The positioning device according to claim 1, wherein the actuator is an electromagnetic actuator using a magnetic material.

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