JP2007295690A - Linear motor, and stage drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a Y axis central drive means which can perform movement control of a Y stage well. <P>SOLUTION: A Y axis central drive means 15C is provided with a columnar stator 152, and a cylindrical moving member 153 provided to cover the side face of the stator 152 while forming a clearance between it and the stator 152. The stator 152 is formed in columnar shape by a core portion 152C formed of a ferromagnetic damping alloy in columnar shape, and an outer circumferential portion 152B formed of a magnet 152B1 in cylindrical shape covering the side face of the core portion 152C. Since the core portion 152C of the stator 152 is formed of a ferromagnetic damping alloy, vibration incident to movement of the moving member 153 can be suppressed even if bending arises in the stator 152. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a linear motor and a stage driving device. For example, the present invention relates to a linear motor and a stage driving device used for machine tools, semiconductor manufacturing apparatuses, and the like.

  For example, as a configuration for driving a stage of a machine tool, a semiconductor manufacturing apparatus, or the like, a configuration in which a stage is driven by moving a slider with a built-in coil along a shaft with a built-in magnet is known. 1).

The one described in Patent Document 1 is a columnar shape that extends in the X-axis direction while being inserted into a mover fixed to the bottom surface of the wafer stage and a round hole formed in the vicinity of the center of the mover. And a stator. Both ends of the stator in the longitudinal direction are held by a pair of holding mechanisms.
And the structure which moves a wafer stage by driving a needle | mover to a X-axis direction with the Lorentz force which generate | occur | produces by the electromagnetic interaction with a stator is taken.

Japanese Patent Laid-Open No. 2001-23894

  However, in the configuration as described in Patent Document 1 described above, since both ends in the longitudinal direction of the stator are held by the pair of holding members, the stator may bend. For this reason, vibration occurs with the movement of the mover, and there is a problem that the movement control of the stage may not be satisfactorily performed.

  In view of such circumstances, an object of the present invention is to provide a linear motor and a stage drive device that can be driven satisfactorily.

The linear motor according to the present invention is formed in a cylindrical shape by bending a coil in a spiral shape and a coil, and a gap is formed between the stator and a side surface of the stator. The stator is provided with a core portion formed in a columnar shape with any one of a damping material and a plurality of magnetic bodies arranged in parallel in one direction, On the other hand, an outer peripheral part formed in a cylindrical shape covering the side surface of the core part is formed in the columnar shape.
According to this invention, the linear motor is provided with the columnar stator and the cylindrical movable element that covers the side surface of the stator and is provided in a state where a gap is formed between the stator and the linear motor. . And, the stator is columnar with a core part formed in a columnar shape by one of the damping material and the magnetic body, and an outer peripheral part formed in a cylindrical shape covering the side surface of the core part by the other Is formed.
For this reason, since the core part or the outer peripheral part of the stator is formed of a damping material, it is possible to suppress vibration accompanying the movement of the mover even if the stator is bent.
Therefore, it is possible to provide a linear motor that can be driven satisfactorily.

In the linear motor of the present invention, it is preferable that the damping material is a damping alloy.
According to this invention, the damping alloy is applied as the damping material.
For this reason, compared with the structure which applies resin as a damping material, it becomes possible to raise the rigidity of a stator and it becomes possible to further suppress the vibration accompanying the movement of a needle | mover.

In the linear motor of the present invention, it is preferable that the damping alloy is an alloy that suppresses vibrations by twinning motion.
According to the present invention, an alloy that suppresses vibration by twinning motion (hereinafter referred to as a twin-type damping alloy) is applied as the damping alloy.
Therefore, a configuration using an alloy that suppresses vibration by crystal dislocation (hereinafter referred to as a dislocation type damping alloy) or an alloy that suppresses vibration by absorption at a domain wall (hereinafter referred to as a ferromagnetic type damping alloy). As compared with the above, vibration can be further suppressed, and a linear motor that can be driven more satisfactorily can be provided.

In the linear motor of the present invention, the damping alloy is an alloy that suppresses vibration by absorption at a domain wall, the core portion is formed in a columnar shape by the plurality of magnetic bodies, and the outer peripheral portion is the domain wall. The structure formed in the cylinder shape by the alloy which suppresses a vibration by absorption of this is preferable.
According to the present invention, the ferromagnetic damping alloy is applied as the damping alloy. Further, the core portion of the stator is formed in a columnar shape with a magnetic material, and the outer peripheral portion is formed in a cylindrical shape with a ferromagnetic damping alloy.
For this reason, when a stator is formed with a ferromagnetic damping alloy, twin damping damping alloy, dislocation damping alloy as a core and a magnetic body as an outer peripheral portion, or with twin damping damping or dislocation damping. The magnetic force of the stator can be increased as compared with the case where the stator is configured with the vibration alloy as the outer peripheral portion and the magnetic body as the core portion. Therefore, the propulsive force of the stator can be increased.

The stage drive apparatus of the present invention includes the above-described linear motor, a pair of holding portions that respectively hold one end and the other end of the linear motor in the longitudinal direction, and a stage attached to the mover of the linear motor. And.
According to the present invention, the stage driving device is provided with the linear motor that can be driven satisfactorily as described above, the holding portion that holds both ends of the linear motor, and the stage attached to the mover of the linear motor. ing.
For this reason, since generation | occurrence | production of the vibration accompanying the movement of a needle | mover is suppressed, it becomes possible to provide the stage drive device which can implement the movement control of a stage favorably.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
<Configuration of Embodiment>
FIG. 1 is a perspective view of a machine tool to which the stage driving device of the present invention is applied, FIG. 2 is a front view of the machine tool, and FIG. 3 is a Y-axis side driving means for driving a Y stage, a Y-axis central driving means, and 4 is a partially enlarged front view showing the linear scale, FIG. 4 is a partially sectional perspective view of the main part of the Y-axis central drive means, and FIG. 5 is a partially enlarged side view showing the drive means for driving the X stage and the linear scale. These are the elements on larger scale which show the drive means for a Z stage drive, and a linear scale.
As shown in FIGS. 1 to 3 and FIGS. 5 and 6, the machine tool of the present embodiment includes a bed 1 and a Y stage 11 supported on the bed 1 so as to be movable in the front-rear direction (Y-axis direction). An X stage 31 supported on the Y stage 11 so as to be movable in the left-right direction (X-axis direction) orthogonal to the moving direction of the Y stage 11, and the Y stage 11 and the X stage 31 on the X stage 31. And a Z stage 51 supported so as to be movable in a vertical direction (Z-axis direction) orthogonal to the moving direction.

  The bed 1 is formed in a U shape when viewed from the front. That is, it is formed in a U shape having the bottom connecting wall portion 2 and the rising wall portion 3 that rises in parallel upward from both sides of the bottom connecting wall portion 2. A table 4 on which a work is placed is disposed on one end side of the bottom connecting wall portion 2. The table 4 may be a simple table, but may have a structure including a moving mechanism that can move in the X, Y, and Z axis directions.

The Y stage 11 is supported by the upper end surface of the compatible upper wall 3 of the bed 1 so as to be movable through the guide means 12, and is provided with two Y-axis side surface driving means 15A and 15B, and a Y-axis central drive as a linear motor. It is moved in the Y-axis direction via the means 15C, and the Y-axis direction position is detected via the three linear scales 25A, 25B, 25C.
The guide means 12 includes a guide rail 13 fixed to the upper end surface of the rising wall portion 3 along the Y-axis direction, and a slider slidable along the guide rail 13 and fixed to the lower surface of the Y stage 11. 14.

The Y-axis side surface driving means 15A, 15B and the Y-axis center driving means 15C are for driving the Y stage 11 in the Y-axis direction (same direction), and as shown in FIG. Means 15A and 15B are arranged, and a Y-axis central driving means 15C is arranged at the center of the lower surface of the Y stage 11.
As shown in FIG. 3, the Y-axis side surface driving means 15 </ b> A and 15 </ b> B includes a stator 16 provided along the Y-axis direction on the outer surface of the compatible upper wall 3 of the bed 1 and brackets on both side surfaces of the Y stage 11. The linear motor includes a mover 17 that is attached to the stator 16 and is opposed to the stator 16 with a gap. The stator 16 is constituted by a coil (not shown) and the mover 17 is constituted by a magnet (not shown), but this may be reversed.

  The Y-axis central drive means 15C includes a stator support member 151 fixed along the Y-axis direction via a support base 19 provided between the rising walls 3 of the bed 1, and the stator support member 151. A stator 152 provided in a supported state, and a mover 153 attached to the center of the lower surface of the Y stage 11 via the bracket 20 and provided in a state where a gap is formed with respect to the stator 152. It is comprised by the linear motor which has.

Here, a detailed configuration of the Y-axis center driving unit 15C will be described.
The stator support member 151 includes, for example, a base portion 151A formed in a rectangular plate shape by SUS (stainless steel), and a pair of holding portions 151B that are erected substantially at the center in the short side direction and at both ends in the longitudinal direction on one surface of the base portion 151A. Is provided.
Bolt holes (not shown) through which bolts (not shown) are inserted along the longitudinal direction are formed at regular intervals on both ends of the base portion 151A in the short direction. The stator support member 151 is fixed to the support base 19 by inserting a bolt into the bolt hole and screwing it into a screwing portion (not shown) of the support base 19.
The holding portion 151B is formed in a rectangular plate shape and is erected in a state where the longitudinal direction is the vertical direction. A fitting groove (not shown) into which the end of the stator 152 is fitted is formed in the mutually facing surfaces of the holding portion 151B. These holding portions 151B hold the stator 152 by fitting the end portions of the stator 152 into the fitting grooves.

The stator 152 is formed in a columnar shape, and both ends in the longitudinal direction are held by the holding portions 151B as described above. As shown in FIG. 4, the stator 152 is provided in a cylindrical cylindrical portion 152A, a cylindrical outer peripheral portion 152B provided in the inner space of the cylindrical portion 152A, and an inner space of the outer peripheral portion 152B. And a cylindrical core portion 152C.
FIG. 4 shows a state in which the end portions of the cylindrical portion 152A, the outer peripheral portion 152B, and the core portion 152C do not exist on the same plane, but actually these end portions exist on the same plane. It is in a state.

The cylindrical portion 152A is formed in a cylindrical shape having an axial length dimension equal to the longitudinal dimension of the base portion 151A, for example, by SUS.
The outer peripheral portion 152B includes a plurality of magnets 152B1 as magnetic bodies. These magnets 152B1 have a short and thick cylindrical shape whose outer diameter is substantially equal to the inner diameter of the cylindrical portion 152A, and the magnetization direction is set in the thickness direction. The plurality of magnets 152B1 are provided in the internal space of the cylindrical portion 152A in a state in which surfaces having different magnetic poles are connected to form a long cylinder.
The core portion 152C is made of a ferromagnetic damping alloy as a damping material, that is, an alloy that suppresses vibrations due to absorption by the domain wall, and is formed in a long cylindrical shape. Specifically, the core portion 152 </ b> C is formed in a columnar shape by Silentaroy (registered trademark), which is an Fe (iron) -Cr (chromium) -Al (aluminum) alloy.
Further, the core 152C has an outer diameter dimension substantially equal to the inner diameter dimension of the outer peripheral part 152B, a length dimension substantially equal to the length dimension of the outer peripheral part 152B, and a radial dimension substantially equal to the wall thickness dimension of the outer peripheral part 152B. It is formed in an equal cylindrical shape.
Here, the ferromagnetic vibration-damping alloy is not limited to the sirenalloy, and various ferritic stainless steels may be used.

The mover 153 is formed in a cylindrical shape, and is provided in a state of surrounding the side surface of the stator 152 and forming a gap with the stator 152.
The movable element 153 includes a coil 153A that is bent in a spiral shape and a covering portion 153B that covers a cylindrical periphery formed by the coil 153A.
The both ends of the coil 153A are connected to power supply means (not shown).
As shown in FIG. 3, the mover 153 is attached to the bracket 20 in a state where the cylindrical axis is parallel to the Y axis.
The mover 153 moves along the Y axis by the power supplied from the power supply means to the coil 153A, and moves the Y stage 11.

  Here, the structure such as the Y stage 11 and the X stage 31 and the Z stage 51 mounted on the Y stage 11 is configured to be symmetrical with respect to the central axis when viewed from the front (front view of FIG. 2).

As shown in FIG. 3, the linear scales 25A, 25B and 25C are provided at positions close to the corresponding Y-axis side surface driving means 15A and 15B and Y-axis central driving means 15C.
The linear scales 25 </ b> A and 25 </ b> B are attached to the scale member 26 provided on the outer surface of the compatible upper wall 3 of the bed 1 along the Y-axis direction and the bracket 18 of the Y stage 11, and have a gap with respect to the scale member 26. It is comprised from the detection head 27 opposingly arranged spaced apart.
The linear scale 25C is attached to the side surface of the stator support member 151 along the Y-axis direction, and is attached to the bracket 20 via the bracket 18 and is opposed to the scale member 26 with a gap. The detection head 27 is made up of.

As shown in FIG. 5, the X stage 31 is supported on the upper end surface of the Y stage 11 so as to be movable via the guide means 32 and the bracket 38, and is moved in the X-axis direction via the driving means 35. The position in the X-axis direction is detected via the linear scale 45.
The X stage 31 (see FIG. 1) includes a main body 41 fixed to the bracket 38, a guide block 42 provided at the front of the main body 41, and a balance weight 43 provided at the rear of the main body 41. Is provided. The balance weight 43 is set so that the center of gravity position of the X stage 31 and the Z stage 51 mounted on the X stage 31 and members (spindle heads, etc.) attached to the X stage 31 is on the center axis of the driving means 35 of the X stage 31. Has been.

The guide means 32 includes a guide rail 33 formed on the upper end surface of the Y stage 11 along the X-axis direction, and a slider 34 slidable along the guide rail 33 and fixed to the lower surface of the bracket 38. It is configured.
The driving means 35 includes a stator 36 fixed along the X-axis direction at the center of the upper surface of the Y stage 11, and a mover attached to the lower surface of the bracket 38 and arranged to face the stator 36 with a gap. 37 and a linear motor.
The linear scale 45 is mounted on the side surface of the stator 36 along the X-axis direction, and is attached to the lower surface of the bracket 38 via the bracket 48 and is opposed to the scale member 46 with a gap. The detection head 47 is made up of.

As shown in FIG. 6, the Z stage 51 is supported on the front surface of the guide block 42 of the X stage 31 through a guide means 52 and a bracket 58 so as to be movable in the Z-axis direction, and through the drive means 55, While moving in the axial direction, the Z-axis direction position is detected via the linear scale 65.
The Z stage 51 (see FIG. 1) is equipped with a spindle head 61 equipped with a tool for processing a workpiece placed on the table 4, and guides the X stage 31 via a bracket 62. A balance cylinder 63 fixed to the upper end of the block 42 is connected. The balance cylinder 63 is configured so that the weight of the Z stage 51 including the bracket 58 and the spindle head 61 can be held by the air pressure in the cylinder, and can be moved up and down with a light force.

The guide means 52 includes a guide rail 53 formed along the Z-axis direction on the front surface of the X stage 31, and a slider 54 slidable along the guide rail 53 and fixed to the back surface of the bracket 58. ing.
The driving means 55 is attached to the front surface of the guide block 42 of the X stage 31 along the Z-axis direction, and is attached to the back surface of the bracket 58 and is disposed opposite to the stator 56 with a gap. It is constituted by a linear motor having a movable element 57.
The linear scale 65 includes a scale member 66 provided on the side surface of the stator 56 and a detection head 67 that is attached to the back surface of the bracket 58 via the bracket 68 and is opposed to the scale member 66 with a gap. It is configured.

<Effect of embodiment>
(1) A cylindrical movable element 153 provided on the Y-axis center driving means 15C in a state where a cylindrical stator 152 and a side surface of the stator 152 are covered and a gap is formed between the stator 152 And. The stator 152 is formed in a columnar shape by a core portion 152C formed in a columnar shape by a damping material and an outer peripheral portion 152B formed in a cylindrical shape covering the side surface of the core portion 152C by a magnet 152B1. ing.
For this reason, since the core part 152 </ b> C of the stator 152 is formed of a vibration damping material, even if the stator 152 is bent, vibration associated with the movement of the mover 153 can be suppressed.
Therefore, it is possible to provide the Y-axis central drive means 15C that can be driven satisfactorily.

(2) As a damping material applied to the core 152C, a ferromagnetic damping alloy is applied.
For this reason, compared with the structure which uses resin as a damping material, the rigidity of the stator 152 can be improved and the vibration accompanying the movement of the needle | mover 153 can further be suppressed.

(3) The machine tool is provided with the Y-axis central driving means 15C that can be driven satisfactorily as described above, and the Y stage 11 attached to the mover 153 of the Y-axis central driving means 15C.
For this reason, since generation | occurrence | production of the vibration accompanying the movement of the needle | mover 153 is suppressed, the movement control of the Y stage 11 can be implemented favorably.

<Modification>
The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

In the above-described embodiment, the linear motor of the present invention is applied only to the Y-axis central drive unit 15C. However, the present invention is not limited to this, and may be appropriately applied to the Y-axis side surface drive units 15A and 15B and the drive units 35 and 55.
Further, two or more linear motors of the present invention may be provided on the Y stage 11, the X stage 31, and the Z stage 51, respectively.
By doing so, the movement control can be favorably performed on the Y stage 11, the X stage 31, and the Z stage 51.

  In the embodiment, the Y axis side surface driving means 15A and 15B for driving the Y stage 11, the Y axis central driving means 15C, the driving means 35 for driving the X stage 31, and the driving means 55 for driving the Z stage 51 are all provided. Although the linear motor is used, the linear motor other than the Y-axis central driving unit 15C may not be used. A feed mechanism using a ball screw shaft may be used.

A stator 752 as shown in FIG. 7 may be applied.
The stator 752 shown in FIG. 7 includes a cylindrical portion 152A, a cylindrical outer peripheral portion 752B provided in the inner space of the cylindrical portion 152A, and a columnar core portion provided in the inner space of the outer peripheral portion 752B. 752C.
The outer peripheral portion 752B is made of a silencer alloy, which is a ferromagnetic damping alloy, and is formed into a short and thick cylindrical shape whose outer diameter is substantially equal to the inner diameter of the cylindrical portion 152A. The wall thickness of the outer peripheral portion 752B is smaller than the wall thickness of the outer peripheral portion 152B of the above embodiment.
The core portion 752C includes magnets 752C1 as a plurality of magnetic bodies. These magnets 752C1 have a short cylindrical shape whose outer diameter is substantially equal to the inner diameter of the outer peripheral portion 752B, that is, the outer diameter is larger than the outer diameter of the core 152C of the above embodiment, and the magnetization direction is thick. The direction is set. The plurality of magnets 752C1 are provided in the inner space of the outer peripheral portion 752B in a state in which surfaces having different magnetic poles are connected to form a long cylinder.

  With such a configuration, when a stator is formed with a ferromagnetic damping alloy, a twin damping damping alloy, a dislocation damping damping core as a core, and a magnet as an outer periphery, or a twin damping damping alloy In addition, the magnetic force of the stator 752 can be increased as compared with the case where the stator is configured with the dislocation type damping alloy as the outer peripheral portion and the magnetic body as the core portion. Therefore, the driving force of the stator 752 can be increased.

Moreover, in the said embodiment and modification, although the core part 152C and the outer peripheral part 752B were formed with the ferromagnetic type damping alloy, you may form with a twin type damping alloy. Here, examples of the twin type vibration damping alloy include Mn (manganese) -Cu (copper) -based alloys and Ni (nickel) -Ti (titanium) -based alloys.
With such a configuration, the vibration can be further suppressed and the drive can be further improved as compared with a configuration using a dislocation type damping alloy or a ferromagnetic type damping alloy.

Further, the core portion 152C and the outer peripheral portion 752B may be formed of a dislocation type damping alloy or a so-called composite type damping alloy. Here, a magnesium alloy can be illustrated as a dislocation type damping alloy. An example of the composite damping alloy is flake graphite cast iron.
Even with such a configuration, the rigidity of the stators 152 and 752 can be increased as in the above-described embodiment, and the vibration associated with the movement of the mover 153 can be further suppressed.

  Further, the core portion 152C and the outer peripheral portion 752B may be formed of a damping resin instead of the damping alloy.

  Although the stators 152 and 752 are cylindrical, the present invention is not limited to this, and the stators 152 and 752 are columnar shapes having a square section or a rectangular section, and the movable element 153 is a cylindrical shape corresponding to the stators 152 and 752. It is good also as a structure.

  Furthermore, although the needle | mover 153 was made into the cylindrical shape, you may form in the cylinder shape of cross-sectional arc shape.

  In the above embodiment, the Y stage 11 is supported so as to be movable in the Y-axis direction with respect to the bed 1, and the X stage 31 is supported on the Y stage 11 so as to be movable in the X-axis direction. Although the configuration is such that 51 is supported so as to be movable in the Z-axis direction, the present invention can also be applied to a structure in which at least one stage is supported so as to be movable in one axial direction.

  In the above embodiment, the spindle head 61 (tool) for machining a workpiece is attached to the Z stage 51, but a measuring head or a workpiece may be used. If a measuring head is attached, a measuring machine for measuring a workpiece placed on the table 4 can be configured. Even when a workpiece is attached, if a spindle head (tool) is prepared separately, it can be configured as a processing machine for processing the workpiece.

  The present invention can be used not only for machine tools and semiconductor manufacturing apparatuses that perform various types of processing on workpieces, but also for measuring apparatuses.

The perspective view which shows the machine tool which concerns on embodiment of this invention. The front view of the machine tool of embodiment same as the above. FIG. 4 is a partially enlarged front view showing a Y-axis side surface driving unit, a Y-axis center driving unit, and a linear scale for driving the Y stage in the same embodiment. The fragmentary sectional perspective view of the principal part of the Y-axis center drive means of embodiment same as the above. FIG. 3 is a partially enlarged side view showing a driving means for driving an X stage and a linear scale in the embodiment. FIG. 3 is a partially enlarged plan view showing a driving means for driving a Z stage and a linear scale in the embodiment. The fragmentary sectional perspective view of the stator and mover which concern on the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Y stage 15C ... Y-axis center drive means as a linear motor 151B ... Holding part 152,752 ... Stator 152B, 752B ... Outer peripheral part 152B1, 752C1 ... Magnet as magnetic body 152C, 752C ... Core part 153 ... Movable element 153A ... Coil

Claims (5)

A stator formed in a columnar shape;
A mover provided in a cylindrical shape by bending a coil in a spiral shape, surrounding the side surface of the stator and forming a gap between the stator and the stator;
With
The stator has a cylindrical portion that is formed in a columnar shape in one of a damping material and a plurality of magnetic bodies arranged in parallel in one direction, and a cylindrical shape that covers the side surface of the core portion in the other The linear motor is characterized by being formed into the columnar shape by an outer peripheral portion formed on the outer periphery. The linear motor according to claim 1,
The linear motor is characterized in that the damping material is a damping alloy. The linear motor according to claim 2,
The damping motor is an alloy that suppresses vibration by a twinning motion. The linear motor according to claim 2,
The damping alloy is an alloy that suppresses vibrations by absorption at the domain wall,
The core is formed in a columnar shape by the plurality of magnetic bodies,
The outer peripheral portion is formed in a cylindrical shape from an alloy that suppresses vibration by absorption by the domain wall. A linear motor according to any one of claims 1 to 4,
A pair of holding portions for holding one end and the other end in the longitudinal direction of the stator of the linear motor;
A stage attached to the mover of the linear motor;
A stage driving device comprising:

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