JP2020120458A - Planar stage device - Google Patents

Abstract

A flat stage device capable of obtaining thrust efficiently is provided. A flat stage device (100) includes a flat platen (10) and a moving body (20) that moves on the platen (10) in a first direction (X direction). The platen 10 includes a base 11 made of carbon fiber plastic in which the orientation direction of carbon fibers is set along the first direction, and a convex pole 12 provided on the base 11 in a stripe shape. . The salient poles 12 are a plurality of bar-shaped magnetic bodies insulated from each other, and are arranged parallel to the first direction at regular intervals with their longitudinal directions coinciding with a second direction orthogonal to the first direction. The moving body 20 has a plurality of magnetic poles 23a, 23c, 23e, . , move in the first direction. [Selection drawing] Fig. 4

Description

The present invention relates to a flat stage device in which a moving body moves on a platen.

2. Description of the Related Art In recent years, in a processing apparatus such as an exposure apparatus, a flat stage has been used in which a movable body that is a work stage for mounting a work on one surface moves on a flat platen.
For example, Patent Document 1 discloses a flat stage in which a moving body moves on a flat platen provided with convex poles in a grid pattern. Here, the moving body includes a mover having a magnetic pole that generates a moving magnetic field in each axial direction of XY coordinate axes orthogonal to each other on the platen plane. In this flat stage, on the platen, a magnetic force is applied to the mover of the moving body that is levitated by the action of air, and the magnetic force between the magnetic pole of the mover and the convex pole of the platen is changed, The moving body is horizontally moved on the platen.

In the above-mentioned flat stage, a permanent magnet is attached to the mover. Further, the mover has magnetic poles provided at intervals according to the intervals of the salient poles of the platen. A coil is wound around each magnetic pole, and when a current is passed through the coil, each magnetic pole becomes an electromagnet. If the direction of the magnetic field produced by the permanent magnet and the direction of the magnetic field produced by the electromagnet are the same, the magnetic fields are mutually strengthened, and if the directions of the magnetic field produced by the permanent magnet and the electromagnet are opposite, the magnetic fields are canceled. Therefore, by controlling the current flowing through the coil wound around each magnetic pole, it is possible to generate thrust in the moving element and move the moving body.
The flat stage having such a configuration is called a surface motor stage, a sawer motor stage, or the like.

Japanese Patent No. 4581641

In the flat stage described in Patent Document 1, one permanent magnet is provided for a mover having a plurality of magnetic poles provided at predetermined intervals along the moving direction of the moving body. Then, the magnetic field generated in each magnetic pole is changed by strengthening or weakening the bias magnetic field in the moving direction of the moving body provided by the permanent magnet, thereby moving the moving body.
However, in this case, the magnetic field strength generated by the permanent magnets varies among the magnetic poles depending on the arrangement position of the permanent magnets in the moving direction of the moving body. Then, even if the magnetic field is generated in the direction of strengthening or canceling the magnetic field created by the permanent magnet by controlling the coil current in each magnetic pole, it is not possible to appropriately provide the magnetic force between the magnetic poles, and it is possible to efficiently Thrust may not be obtained.
Therefore, an object of the present invention is to provide a flat stage device that can efficiently obtain thrust.

In order to solve the above problems, an aspect of a flat stage device according to the present invention is a flat stage device including a flat platen and a moving body that moves on the platen in a first direction, The platen includes a base made of carbon fiber plastic in which the orientation direction of the carbon fibers is set along the first direction, and convex poles provided in stripes on the base, The poles are a plurality of rod-shaped magnetic bodies that are insulated from each other, and have their longitudinal directions aligned with a second direction orthogonal to the first direction, and are arranged parallel to the first direction at regular intervals. The moving body has a plurality of magnetic poles arranged at a predetermined interval in the first direction, and the magnetic force between the magnetic poles and the convex poles generated in the plurality of magnetic poles by the magnetic field in the second direction causes the moving body to move the first magnetic field. Move in one direction.

In this way, the magnetic field in the direction orthogonal to the moving direction of the moving body generates magnetic force between the plurality of magnetic poles arranged at a predetermined interval in the moving direction of the moving body between the convex poles of the platen. Therefore, the magnetic field in the moving direction of the moving body causes a plurality of magnetic poles arranged at a predetermined interval in the moving direction of the moving body to generate magnetic force between the magnetic poles and the salient poles of the platen. It is possible to suppress variations in the magnetic field at the magnetic poles. Therefore, a well-balanced magnetic field can be created in the moving direction of the moving body, and the thrust of the moving body can be efficiently obtained.
Further, the platen has a configuration in which stripe-shaped convex poles are provided on a base made of carbon fiber plastic (CFRP). As described above, since the convex poles are not connected to each other on the contact surface side to the base, even if the thermal expansion coefficient of the convex pole (magnetic material) is larger than the thermal expansion coefficient of the base (CFRP), Warpage and peeling of the convex pole due to changes are unlikely to occur. Further, the longitudinal direction of the salient pole is made to coincide with the direction orthogonal to the orientation direction of the carbon fibers of the base. The coefficient of thermal expansion of the CFRP base is smaller in the direction in which the orientation ratio of the carbon fibers is higher. A direction in which the longitudinal direction of the convex pole is orthogonal to the orientation direction of the carbon fiber of the base, that is, a direction in which the thermal expansion coefficient of the base is large (a direction in which the difference in the thermal expansion coefficient between the base and the convex pole is small). By matching with, it is possible to suppress warping or peeling of the salient pole due to temperature change. In this way, it is possible to provide a platen that is lightweight and has little deformation due to temperature changes.

Further, in the above-mentioned flat stage apparatus, the movable body has, as the plurality of magnetic poles, a plurality of groups of magnetic poles arranged along the second direction, the groups of magnetic poles being arranged along the first direction. A magnetic force generation section that is provided corresponding to each pair and generates a magnetic force between the convex pole by the magnetic field in the second direction and a magnetic force generated by the magnetic force generation section in the corresponding magnetic pole group. A control unit that controls the magnetic force generation unit, and the magnetic force generation unit that winds around a permanent magnet that applies a bias magnetic field in the second direction and around the magnetic pole, and that is perpendicular to the first direction and the second direction. And a coil that applies a magnetic field in a direction, and the control unit may control a current flowing through the coil.
As described above, by providing the magnetic force generation unit for each set of magnetic poles arranged along the moving direction of the moving body, it is possible to suppress the magnetic field strength from being biased to a specific magnetic pole. Therefore, the difference in magnetic force between the magnetic poles in the moving direction of the moving body can be appropriately controlled, and the thrust of the moving body can be efficiently obtained.
Further, in the above-mentioned flat stage apparatus, the permanent magnets may be individually provided above the magnetic poles. As a result, the magnetic field created by the permanent magnets in each magnetic pole can be strengthened, and the thrust of the moving body can be increased.

Further, in the above-mentioned flat stage apparatus, the base may be made of unidirectional carbon fiber reinforced plastic in which carbon fibers are aligned in one direction. In this case, the coefficient of thermal expansion of the base can be appropriately anisotropic. Therefore, the longitudinal direction of the salient pole can be set in a direction in which the difference from the coefficient of thermal expansion of the salient pole becomes smaller, and deformation due to temperature change can be appropriately suppressed.
Further, in the above-mentioned flat stage apparatus, the longitudinal direction of the base may be aligned with the orientation direction of the carbon fibers. In this case, the longitudinal direction of the salient pole can be made to coincide with the lateral direction of the base, and the longitudinal length of the salient pole is equal to or shorter than the lateral direction of the base. can do. Therefore, it is possible to suppress warping or peeling of the salient pole due to temperature change.
Further, the rigidity of the carbon fiber is high in the direction along the orientation direction. Therefore, by aligning the longitudinal direction of the stage with the orientation direction of the carbon fibers, it is possible to realize a stage that is less distorted or bent even if it is a long stage.

Further, an aspect of the flat stage device according to the present invention is a flat stage device including a flat platen provided with a convex pole and a moving body that moves on the platen in a first direction, The moving body has a plurality of sets of magnetic poles arranged along a second direction orthogonal to the first direction on the plane of the platen at predetermined intervals in the first direction, and each of the sets of magnetic poles is provided with the set. A magnetic force generation unit that is provided correspondingly and that generates a magnetic force between the convex pole by the magnetic field in the second direction and a control unit that controls the magnetic force generated by the magnetic force generation unit in the corresponding magnetic pole set. And a magnetic field in a third direction that is wound around each of the permanent magnets that apply a bias magnetic field in the second direction and around the magnetic pole, and that is in a third direction orthogonal to the first direction and the second direction. And a coil for providing the current, and the control unit controls the current flowing through the coil.

As described above, the magnetic field in the direction orthogonal to the moving direction of the moving body generates a magnetic force between each of the plurality of magnetic poles arranged at a predetermined interval in the moving direction of the moving body and the convex pole of the platen. Since the magnetic force generator is provided for each set of magnetic poles arranged along the moving direction of the moving body, it is possible to suppress the magnetic field strength from being biased to a specific magnetic pole. Therefore, the difference in magnetic force between the magnetic poles in the moving direction of the moving body can be appropriately controlled, and the thrust of the moving body can be efficiently obtained.

According to the present invention, it is possible to provide a flat stage device that can efficiently obtain thrust.

It is a schematic block diagram of the planar stage apparatus in this embodiment. It is a perspective view which shows the structure of the platen in this embodiment. It is sectional drawing which shows the structure of the mover in this embodiment. It is an exploded perspective view showing composition of a mover in this embodiment. It is a figure explaining the operation principle of the plane stage device in this embodiment. It is a figure explaining the operation principle of the plane stage device in this embodiment. It is a figure explaining the operation principle of the plane stage device in this embodiment. It is a figure explaining the operation principle of the plane stage device in this embodiment. It is a figure explaining the principle of operation of the conventional flat stage device. It is a figure explaining the principle of operation of the conventional flat stage device. It is a figure explaining the principle of operation of the conventional flat stage device. It is a figure explaining the principle of operation of the conventional flat stage device. It is a figure explaining the subject of the conventional platen. It is a figure explaining the subject of the conventional platen.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a flat stage device 100 according to this embodiment.
The flat stage apparatus 100 includes a flat platen 10 and a moving body 20 that can move on the platen 10 in the horizontal direction (X direction). The flat stage apparatus 100 according to the present embodiment can be used, for example, as a work stage of a processing apparatus that processes the work W.

The platen 10 includes a base 11 and a salient pole 12 provided on the base 11.
The base 11 is made of a carbon fiber reinforced plastic member (CFRP member). The CFRP member has a structure in which a plurality of prepregs are laminated. The prepreg is a sheet-shaped member in which carbon fiber is impregnated with resin while maintaining the directionality of the fiber. The resin forming the prepreg is, for example, a thermosetting epoxy resin. As the resin constituting the prepreg, for example, a thermosetting resin such as unsaturated polyester, vinyl ester, phenol, cyanate ester or polyimide can be used.

In the present embodiment, as the prepreg, a UD (UNI-DIRECTION) material in which the fiber direction extends in only one direction is used. Then, a plurality of UD materials are laminated in the mold so that the directions of the fibers are aligned with each other, heated to about 120° C. to 130° C. under reduced pressure, and then pressed (pressure bonded) to be cured to form a CFRP member. Molded. This makes it possible to obtain a unidirectional CFRP member in which carbon fibers are aligned in one direction.
The CFRP member is not limited to the unidirectional CFRP member as long as the fiber orientation is set so as to have anisotropy.
The CFRP member manufactured in this manner has a lower density (that is, lighter weight) than a metal material such as iron or aluminum, but has a high strength. The base 11 is a member obtained by cutting the completed CFRP member into a desired size.

In the base 11, the orientation direction of the carbon fibers is set along the X direction which is the moving direction of the moving body 20. Here, the orientation direction of the carbon fibers is the direction in which the fiber orientation ratio is the highest in the entire laminated structure. That is, the base 11 is composed of a CFRP member in which a plurality of UD materials are laminated so that the carbon fibers are aligned in the X direction.
Further, the base 11 can be a member having an elongated shape whose longitudinal direction is aligned with the X direction which is the orientation direction of the carbon fibers. For example, the length of the base 11 in the X direction is about 4 m, and the length of the base 11 in the Y direction can be about 100 mm to 200 mm.

Then, as shown in FIG. 2, stripe-shaped convex poles 12 are provided on the base 11. As shown in FIG. 2, the salient pole 12 is composed of a plurality of rod-shaped magnetic bodies (metals). The rod-shaped salient poles 12 are arranged in parallel along the X direction at regular intervals, with their longitudinal directions aligned with the Y direction. That is, the longitudinal direction of the salient pole 12 is a direction orthogonal to the moving direction of the moving body 20, and coincides with the Y direction which is a direction orthogonal to the orientation direction of the carbon fibers of the base 11.
In FIG. 2, the length of the salient pole 12 in the Y direction (longitudinal direction) is shorter than the length of the base 11 in the Y direction, but may be the same as the length of the base 11 in the Y direction.

The salient pole 12 is fixed to the base 11 with, for example, a resin adhesive. Note that the illustration of the above-mentioned adhesive is omitted in FIGS. 1 and 2.
Further, as shown in FIG. 1, a space between the salient poles 12 and the salient poles 12 is filled with a non-magnetic material 13. The non-magnetic body 13 is made of resin, for example. Note that the non-magnetic body 13 is not shown in FIG.
As described above, the salient poles 12 are arranged in parallel along the orientation direction of the carbon fibers of the CFRP member that is the base 11, and the salient poles 12 are independent of each other and are insulated from each other. That is, the salient poles 12 are not electromagnetically connected.

The flat stage apparatus 100 according to the present embodiment levitates the moving body 20 on the platen 10 with air, applies a magnetic force to the moving body 20, and applies a magnetic force between the moving body 20 and each salient pole 12 of the platen 10. By changing it, the moving body 20 is moved in the horizontal direction (X direction).
One surface (upper surface in FIG. 1) of the moving body 20 is a stage surface for mounting the work W, and the other surface (lower surface in FIG. 1) is arranged at a predetermined interval in the X direction. A mover 21 having a plurality of magnetic poles is provided. Although not particularly shown, an air pad that blows out air is provided on the other surface of the moving body 20.

The mover 21 according to the present embodiment has a convex pole on each of a plurality of magnetic poles arranged at predetermined intervals in the X direction by a magnetic field in a direction (Y direction) orthogonal to the X direction, which is the moving direction of the moving body 20. A magnetic force between 12 and 12 is generated. The moving body 20 moves in the X direction by the magnetic force generated between the magnetic pole of the moving element 21 and the salient pole 12.
In the following description, a mechanism for applying a magnetic force to a moving element by a magnetic field in a direction orthogonal to the moving direction of the moving element is referred to as a "transverse method", and a mechanism along the moving direction of the moving element (parallel to the moving direction) is used. ) A mechanism that applies a magnetic force to a moving element by a magnetic field is called an “axial method”.

FIG. 3 is a cross-sectional view showing the configuration of the mover 21. In FIG. 3, the mover 21 moves in the direction perpendicular to the paper surface.
The mover 21 includes a magnetic pole 23a wound with a coil 22a and a magnetic pole 23b wound with a coil 22b. The magnetic poles 23a and 23b are provided such that their magnetic pole surfaces face the upper surfaces of the salient poles 12 of the platen 10. The mover 21 has permanent magnets 24a and 24b that are individually arranged above the magnetic poles 23a and 23b, and a back yoke 25 that is arranged on the permanent magnets 24a and 24b so as to connect the magnetic poles 23a and 23b. And The back yoke is a magnetic body (metal).
The drive circuit (control unit) 30 can control the current flowing through the coils 22a and 22b.

With the configuration shown in FIG. 3, the permanent magnets 24a and 24b generate a bias magnetic field indicated by a dotted arrow in the Y direction, which is the direction in which the salient poles 12 of the platen 10 extend (the direction orthogonal to the moving direction of the moving body 20). give. When a current is applied to the coils 22a and 22b, the magnetic poles 23a and 23b become electromagnets and apply a magnetic field in the Z direction according to the direction of the coil current.
As a result, a magnetic force is generated between the magnetic pole pair 23a and 23b and the convex pole 12. Further, by controlling the current flowing through the coils 22a, 22b by the drive circuit 30, the bias magnetic field provided by the permanent magnets 24a, 24b can be strengthened or weakened by the magnetic field created by the electromagnets, and the magnetic pole sets 23a, 23b can be formed. The generated magnetic force can be changed.
As described above, the mover 21 is provided with a magnetic force generation unit that generates magnetic force between the magnetic pole set 23a and 23b and the convex pole 12 by the magnetic field in the Y direction. Here, the coils 22a and 22b corresponding to the magnetic poles 23a and 23b, the permanent magnets 24a and 24b, and the back yoke 25 correspond to the magnetic force generator.

Further, the mover 21 has a plurality of magnetic pole sets (the magnetic poles 23a and 23b in FIG. 3) arranged along the Y direction at predetermined intervals along the X direction. Furthermore, the mover 21 includes a plurality of magnetic force generation units corresponding to the plurality of magnetic pole sets.
FIG. 4 is an exploded perspective view of the mover 21. In FIG. 4, the magnetic poles 23a and 23b, the magnetic poles 23c and 23d, the magnetic poles 23e and 23f, and the magnetic poles 23g and 23h are a set of magnetic poles. In addition, illustration of the coil is omitted in FIG. Although the number of magnetic pole groups is four in FIG. 4, the number of magnetic pole groups is not limited to the number shown in FIG.

As shown in FIG. 4, the mover 21 includes a set of four magnetic poles and four sets of magnetic force generators provided corresponding to the sets of magnetic poles.
That is, the permanent magnets 24a to 24h are arranged on the magnetic poles 23a to 23h, and the magnetic poles 23a and 23b, the magnetic poles 23c and 23d, the magnetic poles 23e and 23f, and the magnetic poles 23g and 23h are arranged on the permanent magnets 24a to 24h. The back yoke 25 is arranged so as to connect to each other. A coil (not shown) is wound around each of the magnetic poles 23a to 23h, and the magnetic force between each magnetic pole and the salient pole 12 is changed by controlling the current flowing through the coil. You can

Next, the operation of the mover 21 will be described with reference to FIGS. 5 to 8, the horizontal direction of the drawings is the moving direction of the moving body 20. 5 to 8, the convex pole 12 of the platen 10 is a convex pole 12a, a convex pole 12b, a convex pole 12c,... In order from the upstream side in the moving direction of the moving body 20.
5 to 8 show the moving element 21 viewed from the magnetic poles 23a, 23c, 23e and 23g side. The magnetic poles 23b, 23d, 23f and 23h are present on the back side of the magnetic poles 23a, 23c, 23e and 23g, respectively.
As shown in FIGS. 5 to 8, a plate member 26 having good flatness is provided on each back yoke 25, and the plate member 26 can be used as a work stage for mounting the work W.

The salient pole 12a, the salient pole 12b, the salient pole 12c,... Are provided at regular intervals. The space between the convex poles of the platen 10 is filled with the non-magnetic body 13, and the width of the convex pole of the platen 10 and the width of the non-magnetic body 13 in the X direction are equal.
Further, in the X direction, when the width and spacing of the convex poles of the platen 10 are a (the pitch P of the convex poles is 2a), the spacing between the magnetic poles 23a and 23c is 2a, and the spacing between the magnetic poles 23c and 23e is The distance between the magnetic pole 23e and the magnetic pole 23g is 2.5a.
Although not shown in particular, the ends of the magnetic poles of the mover 21 on the side facing the platen 10 may be composed of a plurality of smaller convex poles. In this case, the pitch of the small salient poles is equal to the pitch of the salient poles of the platen 10. Further, in the present embodiment, since the operation is described using four magnetic pole sets, the magnetic pole spacing in the X direction is set to the above value, but the magnetic pole spacing is appropriately set according to the number of magnetic pole sets. It shall be.

As described above, the coils 22a to 22h are wound around the magnetic poles 23a to 23h, and when a current is applied to the coils 22a to 22h, the magnetic poles 23a to 23h become electromagnets. If the directions of the magnetic fields created by the permanent magnets 24a to 24h and the electromagnet are the same, the magnetic fields strengthen each other. On the other hand, if the magnetic fields generated by the permanent magnets 22a to 22h and the magnetic field generated by the electromagnet are opposite, the magnetic field is canceled.
A current can be passed from the drive circuit 30 to the coils 22a to 22h wound around the magnetic poles 23a to 23h, and the magnetic pole strongly attracted to the salient pole 12 is changed by controlling the current passed to the coils 22a to 22h. Can be made. As a result, the mover 21 moves in the left-right direction in FIGS.

Hereinafter, the operating principle of the moving element 21 moving to the right in FIGS. 5 to 8 will be described.
5 to 8 are views of the moving element 21 viewed from the magnetic poles 23a, 23c, 23e, and 23g side, the operation of the magnetic poles 23a, 23c, 23e, and 23g will be described as an example. Similar operations are performed for 23b, 23d, 23f, and 23h.
(1) STEP 1: As shown in FIG. 5, a current is applied to the coil 22 a of the magnetic pole 23 a of the moving element 21 so as to strengthen the magnetic force of the magnetic pole 23 a. On the other hand, a current is passed through the coil 22c of the magnetic pole 23c so as to cancel the magnetic force of the magnetic pole 23c. Further, no current is passed through the coil 22e of the magnetic pole 23e and the coil 22g of the magnetic pole 23g.
Since the magnetic force of the magnetic pole 23a is strengthened, the magnetic pole 23a strongly attracts the convex pole 12a of the platen 10, and the magnetic pole 23a and the convex pole 12a face each other.
The magnetic force of the magnetic pole 23c is canceled, and the magnetic pole 23c is located on the non-magnetic body 13 between the salient poles 12b and 12c. The magnetic pole 23e and the magnetic pole 23g attract the salient pole 12d and the salient pole 12f, respectively.

(2) STEP2: As shown in FIG. 6, the current of the coil 22a of the magnetic pole 23a and the coil 22c of the magnetic pole 23c is stopped, and the current is supplied to the coil 22g of the magnetic pole 23g so as to strengthen the magnetic force of the magnetic pole 23g. In addition, a current is applied to the coil 22e of the magnetic pole 23e so as to cancel the magnetic force.
The magnetic pole 23g strongly attracts the convex pole 12f, and the magnetic pole 23e cancels the magnetic force, so that it does not attract the convex pole 12d. Therefore, the mover 21 moves rightward in the figure so that the magnetic pole 23g faces the convex pole 12f. The magnetic pole 23a and the magnetic pole 23c attract the salient pole 12a and the salient pole 12c, respectively.

(3) STEP3: As shown in FIG. 7, the current of the coil 22g of the magnetic pole 23g and the coil 22e of the magnetic pole 23e is stopped, and the current is supplied to the coil 22c of the magnetic pole 23c so as to strengthen the magnetic force of the magnetic pole 23c. Further, a current is passed through the coil 22a of the magnetic pole 23a so as to cancel the magnetic force of the magnetic pole 23a.
The magnetic pole 23c strongly attracts the convex pole 12c, the magnetic force of the magnetic pole 23a is canceled, and the magnetic pole 23a does not attract the convex pole 12a. Therefore, the mover 21 moves rightward in the figure so that the magnetic pole 23c faces the convex pole 12c. The magnetic pole 23e and the magnetic pole 23g attract the salient pole 12e and the salient pole 12f, respectively.
(4) STEP4: As shown in FIG. 8, the current of the coil 22a of the magnetic pole 23a and the coil 22c of the magnetic pole 23c is stopped, and the current is passed through the coil 22e of the magnetic pole 23e so as to strengthen the magnetic force of the magnetic pole 23e. Further, a current is applied to the coil 22g of the magnetic pole 23g so as to cancel the magnetic force of the magnetic pole 23g.
The magnetic pole 23e strongly attracts the salient pole 12e, and the magnetic pole 23g cancels the magnetic force, so that it does not attract the salient pole 12f. Therefore, the mover 21 moves rightward in the figure so that the magnetic pole 23e faces the convex pole 12e.

Here, the operation of the conventional axial type flat stage device will be described with reference to FIGS.
As shown in FIGS. 9 to 12, the conventional flat stage apparatus has a configuration in which the mover 221 can move on the platen 210.
Here, the platen 210 has a plurality of ferromagnetic salient poles 212a, 212b, 212c,... Provided at regular intervals in the X direction. A space between the salient poles is filled with a non-magnetic material 213. The convex poles are electrically connected at the bottom.
The mover 221 includes magnetic poles 223a and 223b around which the coil 222a is wound, and magnetic poles 223c and 223d around which the coil 222b is wound. Further, the mover 221 is provided with a permanent magnet 224 at its center position. The permanent magnet 224 generates a magnetic field in the four magnetic poles 223a to 223d in a direction along the moving direction (X direction) of the moving element 221.

When a current is applied to the coils 222a and 222b, the magnetic poles 223a to 223d become electromagnets. If the magnetic field created by the permanent magnet 224 and the magnetic field created by the electromagnet are in the same direction, the magnetic fields are mutually strengthened, and if the magnetic field created by the permanent magnet 224 and the magnetic field created by the electromagnet are opposite, the magnetic field is canceled. It should be noted that + and − in FIGS. 9 to 12 indicate the direction of current flowing through the coil.
A current can be supplied from a drive circuit (not shown) to the coils 222a and 222b wound around the magnetic poles 223a to 223d. As a result, a moving magnetic field is generated, and the mover 221 moves in the left-right direction in FIGS. 9 to 12.
The relationship between the pitch of the convex poles of the platen 210 and the pitch of the magnetic poles of the mover 221 is the relationship between the pitch of the convex poles of the platen 10 and the pitch of the magnetic poles of the mover 21 shown in FIGS. The same is true.

The operating principle of the mover 221 moving to the right in FIGS. 9 to 12 will be described below.
(1) STEP 1: As shown in FIG. 9, a current is applied to the coil 222a on the magnetic poles 223a and 223b side of the moving element 221 so as to increase the magnetic force of the magnetic pole 223a. No current is passed through the coil 222b of the magnetic poles 223c and 223d. Since the magnetic force of the magnetic pole 223a is strengthened, the magnetic pole 223a strongly attracts the salient pole 212a of the platen 210, and the magnetic pole 223a and the salient pole 212a face each other.
The magnetic force of the magnetic pole 223b is canceled, and the magnetic pole 223b is located on the non-magnetic body 213 between the salient poles 212b and 212c. The magnetic pole 223c and the magnetic pole 223d attract the salient pole 212d and the salient pole 212f, respectively.
(2) STEP2: As shown in FIG. 10, the current of the coil 222a on the magnetic poles 223a and 223b side is stopped, and the current is applied to the coil 222b on the magnetic poles 223c and 223d side so as to strengthen the magnetic force of the magnetic pole 223d. The magnetic pole 223d strongly attracts the salient pole 212f, and the magnetic pole 223c cancels the magnetic force, so that it does not attract the salient pole 212d.
Therefore, the mover 221 moves rightward in the figure so that the magnetic pole 223d faces the salient pole 212f. The magnetic pole 222a and the magnetic pole 222b attract the salient pole 212a and the salient pole 212c, respectively.

(3) STEP 3: As shown in FIG. 11, the current of the coil 222b on the side of the magnetic poles 223c and 223d is stopped, and the current is applied to the coil 222a on the side of the magnetic poles 223a and 223b so as to strengthen the magnetic force of the magnetic pole 223b. The magnetic pole 223b strongly attracts the salient pole 212c, and the magnetic pole 223a cancels the magnetic force so that it does not attract the salient pole 212a.
Therefore, the mover 221 moves rightward in the figure so that the magnetic pole 223b faces the convex pole 212c. The magnetic pole 222c and the magnetic pole 222d attract the salient pole 212e and the salient pole 212f, respectively.
(4) STEP4: As shown in FIG. 12, the current of the coil 222a on the magnetic poles 223a and 223b side is stopped, and the current is supplied to the coil 222b on the magnetic poles 223c and 223d side so as to strengthen the magnetic force of the magnetic pole 223c. The magnetic pole 223c strongly attracts the salient pole 212e, and the magnetic pole 223d cancels the magnetic force, so that it does not attract the salient pole 212f.
Therefore, the mover 221 moves rightward in the figure so that the magnetic pole 223c faces the salient pole 212e.

As described above, in the conventional flat stage apparatus, the magnetic fields 223 a to 223 d of the moving element 221 are given a magnetic field in the direction along the moving direction (X direction) of the moving element 221 by the permanent magnet 224. Therefore, the salient poles of the platen 210 are separated by the non-magnetic material 213 on the surface of the platen 210, but they must be electrically connected at the bottom. Therefore, the conventional platen 210 is entirely made of a metal that is a magnetic material.
However, when the flat stage device is used as a work stage of a processing device that moves a large work for a long distance, the platen becomes large according to the moving distance of the moving element. In addition, the platen requires high flatness. In order to maintain such a large size and high flatness, it is necessary for the entire platen to have high rigidity, and for that purpose, it is necessary to increase the thickness of the platen. When the entire platen is made of metal, the platen becomes a large and thick metal block, and the entire planar stage apparatus becomes very heavy. Further, when the work is large and heavy, it is conceivable to fix the side on which the work is placed and move the platen side to process the work. Therefore, it is desirable that the platen be lightweight.

In order to reduce the weight of the platen, as in the platen 210A shown in FIG. 13, a thin metal plate 212A having a large number of salient poles formed on the surface of a base 211A made of a lightweight and highly rigid CFRP member. It is conceivable to attach the with an adhesive. Here, a space between the salient poles is filled with a non-magnetic material 213A which is a resin. With such a structure, the weight is extremely light as compared with the case where the entire platen is made of metal.
However, when the structure like the platen 210A shown in FIG. 13 is adopted, the following problems occur.
The coefficient of thermal expansion differs greatly between metal and CFRP. Metal has a large coefficient of thermal expansion, and CFRP has a very small coefficient of thermal expansion. For example, the coefficient of thermal expansion (CTE) of iron is 10×10 ⁻⁶ , and the coefficient of thermal expansion (CTE) of CFRP is 0.5 to −1.5×10 ⁻⁶ . Therefore, due to the difference in thermal expansion coefficient between the two, a slight temperature change in the environment in which the platen is installed causes deformation such as warpage in the entire platen. In some cases, as shown in FIG. 14, the metal plate 212A may peel off from the base (CFRP) 211A that is the main body of the platen 210A.

As described above, when two kinds of materials having different thermal expansion coefficients and having a large area, or ones elongated in one direction are pasted together, as described above, the two warp due to temperature change. And peeling will occur.
On the other hand, the platen 10 of the flat stage apparatus 100 according to the present embodiment has a configuration in which the stripe-shaped convex poles 12 are provided on the base 11 made of a CFRP member. Thus, each salient pole 12 has a rod-like shape and is independently arranged on the base 11. That is, the salient poles 12 are not connected to each other on the contact surface side to the base 11. Therefore, even if the coefficient of thermal expansion of the metal (magnetic material) that is the salient pole 12 is larger than the coefficient of thermal expansion of the prepreg (CFRP) that is the base 11, the warping or peeling of the salient pole 12 due to temperature change does not occur. Unlikely to occur. Because the length of each salient pole 12 in the X direction is short, the actual amount of thermal expansion and contraction is small, and when the non-magnetic body 13 between the salient poles 12 is resin, the expansion and contraction of the resin is This is because it absorbs expansion and contraction.
Moreover, the longitudinal direction of the salient pole 12 coincides with the direction orthogonal to the longitudinal direction of the base 11. That is, the salient pole 12 has a length equal to or shorter than the length of the base 11 in the lateral direction. As described above, since the salient pole 12 is made of a relatively short rod-shaped member, the salient pole 12 is unlikely to warp or peel off due to temperature change.

Further, in the present embodiment, the base 11 of the platen 10 can be a CFRP member in which a plurality of prepregs are laminated so that the fiber directions are the same. Then, the longitudinal direction of the base 11 is aligned with the orientation direction of the carbon fibers of the base 11, and the longitudinal direction of the salient pole 12 is aligned with the direction orthogonal to the orientation direction of the carbon fibers of the base 11. You can
In the case of a CFRP member in which the orientation of carbon fibers has anisotropy, the coefficient of thermal expansion in the direction of orientation of the carbon fibers is close to the coefficient of thermal expansion of a single fiber. The coefficient of thermal expansion of the fiber itself is very small. Therefore, the coefficient of thermal expansion in the orientation direction of the carbon fiber is small (compared to the direction orthogonal to the orientation direction). In the case of the above configuration, the longitudinal direction of the salient poles 12 is made to coincide with the direction in which the thermal expansion coefficient of the base 11 is large, that is, the direction in which the difference from the thermal expansion coefficient with the salient poles (magnetic material=metal) 12 is small. Therefore, in the direction in which the coefficient of thermal expansion of the base 11 is small, that is, in the direction in which the difference between the coefficient of thermal expansion and the convex pole (magnetic material=metal) 12 is large, the convex poles 12 are not connected to each other independently. Further, the salient pole 12 is rod-shaped, and the length of the salient pole 12 is very short in this direction. Therefore, even if the difference between the coefficient of thermal expansion of the salient pole 12 and the coefficient of thermal expansion of the base 11 is large, the amount by which the salient pole 12 actually expands due to temperature change is small, so that the salient pole 12 warps or peels off. There is no such thing.
In addition, since the carbon fiber has a high rigidity in the orientation direction, by making the longitudinal direction of the stage coincide with the orientation direction of the carbon fibers, it is possible to reduce distortion and deflection even in a long stage.
As described above, the platen 10 according to the present embodiment can be a platen that is light in weight, deforms due to a temperature change, and further has less deflection due to its own weight and less distortion.

Further, in the conventional axial type flat stage device shown in FIGS. 9 to 12, one permanent magnet 224 is provided for the moving element 221 having a plurality of magnetic poles 223a to 223d arranged along the X direction. ing. 9 to 12, the permanent magnet 224 is provided at the center position of the moving element 221 in the X direction. In this case, the strength of the magnetic field generated by the permanent magnet 224 varies among the magnetic poles 223a to 223d. Specifically, the magnetic fields 223b and 223c close to the permanent magnet 224 have a strong magnetic field, and the magnetic poles 223a and 223d far from the permanent magnet 224 have a weak magnetic field.
In this way, if there is a difference in the bias magnetic fields given by the permanent magnets among the magnetic poles 223a to 223d arranged side by side in the moving direction of the moving body, the thrust of the moving body may not be efficiently obtained. This is because even if the coil current of each magnetic pole is controlled to generate a magnetic field in a direction that strengthens or cancels the magnetic field created by the permanent magnet, it is not possible to appropriately provide a magnetic force difference between the magnetic poles.

On the other hand, the flat stage apparatus 100 according to the present embodiment is a flat stage apparatus that uses the transverse method instead of the conventional axial method. That is, the moving body 20 of the planar stage apparatus 100 is in a direction orthogonal to the moving direction of the moving body 20 with respect to the plurality of magnetic poles arranged at predetermined intervals in the moving direction (X direction) of the moving body 20. It moves in the X direction by the magnetic force generated by applying a magnetic field in the (Y direction).
Specifically, the moving body 20 of the flat stage apparatus 100 has a plurality of pairs of magnetic poles arranged side by side in the Y direction in the X direction. Further, the moving body 20 includes a magnetic force generation unit that generates a magnetic force by a magnetic field in the Y direction with respect to the magnetic pole sets, corresponding to the plurality of magnetic pole sets. Each magnetic force generation unit includes a permanent magnet that applies a bias magnetic field in the Y direction, and a coil that winds around the magnetic pole and that applies a magnetic field in the Z direction, and each magnetic force is generated by controlling the current flowing through the coil. The magnetic force generated by the section can be controlled.

As described above, by adopting the transverse method, it is possible to suppress the above-described problem of the magnetic field variation and easily create a well-balanced magnetic field in the X direction, which is the moving direction of the moving body 20. Further, since the magnetic force generating portion can be provided for each set of magnetic poles arranged along the moving direction of the moving body 20, it is possible to prevent the magnetic field strength from being biased to a specific magnetic pole. Therefore, the difference in magnetic force between the magnetic poles in the moving direction of the moving body 20 can be appropriately controlled, and the thrust of the moving body 20 can be efficiently obtained.
Furthermore, the permanent magnets that form the magnetic force generator may be arranged for each magnetic pole. In this case, the permanent magnets can be arranged above (immediately above) each magnetic pole. As a result, the magnetic field created by the permanent magnets in each magnetic pole can be strengthened, and the thrust of the moving body 20 can be increased.
As described above, in the flat stage apparatus 100 according to the present embodiment, the variation of the magnetic field is suppressed, and the thrust of the moving body 20 can be efficiently obtained.

(Modification)
In the above embodiment, the planar stage device 100 in which the moving body can move only in one direction (X direction) has been described. However, if two flat stage devices 100 are used and they are combined in an orthogonal direction (if another stage device is placed on the first stage device), the moving body is placed on the platen plane. The flat stage device can be moved in two orthogonal directions, so-called XY directions.
Further, in the above-mentioned embodiment, as shown in FIG. 4, the case where the permanent magnets are arranged on the respective magnetic poles of the moving element 21 has been described. However, one permanent magnet is arranged for each magnetic force generation unit. Good. That is, you may make it arrange|position one permanent magnet with respect to the group of magnetic poles (for example, magnetic pole 23a and magnetic pole 23b) arrange|positioned along with the direction orthogonal to the moving direction of the moving body 20. Also in this case, it is possible to suppress the variation of the magnetic field as compared with the conventional axial type flat stage device shown in FIGS. 9 to 12.

The flat stage apparatus 100 in the present embodiment can be used as, for example, a work stage of an exposure apparatus that exposes a work. Further, the flat stage apparatus 100 according to the present embodiment can also be used as a stage of a laser processing apparatus that processes a workpiece, for example, by irradiating a substrate with a laser to form a via hole. Furthermore, the flat stage apparatus 100 according to the present embodiment can also be used as a stage of a processing apparatus such as a wafer defect inspection apparatus or a component mounting apparatus.

10... Platen, 11... Base (CFRP member), 12... Convex pole, 13... Nonmagnetic material, 20... Moving body, 21... Moving element, 22a, 22b... Coil, 23a, 23b... Magnetic pole, 24a, 24b... Permanent magnet, 25... Back yoke, 26... Plate member, 100... Planar stage device, W... Work

Claims (6)

A flat stage device comprising: a flat platen; and a moving body that moves on the platen in a first direction,
The platen is
A base made of carbon fiber plastic in which the orientation direction of the carbon fibers is set along the first direction,
And a convex pole provided in a stripe shape on the base,
The salient poles are a plurality of rod-shaped magnetic bodies that are insulated from each other, and are arranged parallel to each other in the first direction with their longitudinal directions aligned with a second direction orthogonal to the first direction. ,
The moving body is
A plurality of magnetic poles arranged at a predetermined interval in the first direction,
A flat stage apparatus characterized in that it moves in the first direction by the magnetic force between the convex poles generated in the plurality of magnetic poles by the magnetic field in the second direction. The moving body is
As the plurality of magnetic poles, a plurality of pairs of magnetic poles arranged along the second direction are provided along the first direction,
A magnetic force generation unit that is provided corresponding to each of the magnetic pole sets and that generates a magnetic force between the corresponding magnetic pole set and the convex pole by the magnetic field in the second direction;
A control unit that controls the magnetic force generated by the magnetic force generation unit,
The magnetic force generation unit,
A permanent magnet that applies a bias magnetic field in the second direction,
A coil that is wound around each of the magnetic poles and that applies a magnetic field in a third direction orthogonal to the first direction and the second direction,
The flat stage apparatus according to claim 1, wherein the control unit controls a current flowing through the coil. The flat stage apparatus according to claim 2, wherein the permanent magnets are individually provided above the magnetic poles. 4. The flat stage apparatus according to claim 1, wherein the base is made of unidirectional carbon fiber reinforced plastic in which carbon fibers are aligned in one direction. 5. The flat stage apparatus according to claim 1, wherein a longitudinal direction of the base is aligned with an orientation direction of the carbon fibers. A flat stage apparatus comprising: a flat platen provided with a salient pole; and a moving body that moves on the platen in a first direction,
The moving body is
A plurality of pairs of magnetic poles arranged along a second direction orthogonal to the first direction on the plane of the platen at predetermined intervals in the first direction,
A magnetic force generation unit that is provided corresponding to each of the magnetic pole sets and that generates a magnetic force between the corresponding magnetic pole set and the convex pole by the magnetic field in the second direction;
A control unit that controls the magnetic force generated by the magnetic force generation unit,
The magnetic force generation unit,
A permanent magnet that applies a bias magnetic field in the second direction,
A coil that is wound around each of the magnetic poles and that applies a magnetic field in a third direction orthogonal to the first direction and the second direction,
The flat stage apparatus, wherein the control unit controls a current flowing through the coil.

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