JP2000014119A - Linear motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear motor in which a stator and a mover can be assembled accurately and easily. SOLUTION: A linear motor 1 is made up of a stator 2 formed in a recessed shape in cross-section and provided with magnetic field generators 2c on the inside surface 2bw of the side walls which from the recessed part 2a, and a mover formed in a protruding shape in cross-section and provided with coils on the protruding part 3a. A groove 2e and a projection 3c of a V-shape in cross-section are each formed on the surfaces which face each other when the stator 2 and mover 3 are assembled. The groove 2e and projection 3c function as positioning members at the fine of assembly of the stator 2 and mover 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a linear motor for driving a stage or the like.

[0002]

2. Description of the Related Art A linear motor is composed of a stator (or a moving member) having a magnet and a moving member (or a stator) having a coil.
The moving member is caused to travel along the stator by using a repulsive force (or an attractive force) between the magnet and the coil. If such a linear motor is installed as a stage drive source in a stage device, for example, the stage can be driven in a high-speed and non-contact manner, so that excellent performance such as extremely high-precision positioning and high-speed response can be obtained. Can be enjoyed. Incidentally, a motor provided with a magnet in the stator is called a moving magnet type linear motor, and a motor provided with a coil in the stator is called a moving coil type linear motor.

[0003] Examples of linear motors that are actually used include a drive source for a parts transport trolley in a factory, and manufacture of semiconductor devices, liquid crystal display devices, image pickup devices (such as CCDs), thin film magnetic heads, and the like. Examples can be cited as examples used as a drive source for a stage or the like incorporated in an exposure apparatus to be used. In particular, the background of the use of a linear motor as a stage drive source built into an exposure apparatus is to respond to the demand for ultra-fine processing of the above-mentioned semiconductor devices, etc., which has been increasing in recent years. There is. That is, in order to realize more advanced fine processing, a reticle (or photomask), a wafer (or glass plate)
This is because it is an essential requirement to position such a device with high accuracy with respect to the projection optical system or the like. This is a straightforward factor in the use of linear motors as stage drive sources.

[0004] By the way, various concrete forms of the stator and the mover have been proposed.
For example, in the concave portion of the stator having a concave cross section,
The projecting portion of the mover having a convex cross section is inserted into the projecting portion, and a magnetic motor provided on the wall surface forming the recess and a coil provided on the projecting portion constitute a linear motor. There is something.

[0005]

The above-described linear motor has the following problems. Now, taking a moving coil type linear motor as an example, when assembling a stator with a magnet and a mover with a coil, the relative positional relationship between the magnet and the coil,
More specifically, the stator and the mover must be assembled so that the distance between them becomes a certain appropriate value.
Speaking of the stator with a concave cross section and the mover with a convex cross section,
As shown in FIG. 7, both the recess wall surface a and the protrusion wall surface b must be assembled so that they are equal.

[0006] As described above, the linear motor is realized by magnetic mutual interference between the magnet and the coil. That is, the operation of the mover is achieved by an electromagnetic force derived from mutual interference between the magnetic field excited by the coil to which the current is applied and the magnetic field formed by the magnet. Therefore, it is physically clear that the distance between the magnet and the coil greatly affects the behavior performance of the moving element.

For this reason, when the stator and the mover are assembled without maintaining a proper distance between the magnet and the coil, accurate movement of the mover can no longer be expected. That is, it is almost impossible to perform high-precision positioning or the like necessary for the stage operation in the above-described exposure apparatus.

[0008] As described above, the assembling work of the stator and the moving element is extremely important work.
This can be a very laborious task. In particular, conventionally, since the stator and the mover have been manufactured independently of each other, it has been more difficult to position each other during the assembling work.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a linear motor capable of accurately and easily assembling a stator and a moving member. .

[0010]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the linear motor according to claim 1 is a linear motor including a stator and a movable member movable with respect to the stator, wherein a positioning member for positioning the stator and the movable member is provided. It is characterized by the following.

According to this, the relative positioning of the stator and the movable element, which is necessary when assembling the stator and the movable element, is performed by the positioning member, so that the work can be performed accurately and easily. It is possible to do.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing an outline of the linear motor 1. The linear motor 1 includes a stator 2 and a moving element 3. The stator 2 is a long columnar body having a concave cross section, and the moving element 3 is a short columnar body having a convex cross section. When both are assembled, the protrusion 2a having a convex cross section of the moving element 3 is inserted into the concave portion 2a of the stator 2 having a concave cross section.

A plurality of magnets (magnetizers) 2c are provided on the inner wall surface 2bw of the side wall 2b forming the concave portion 2a having a concave cross section of the stator 2. These magnets 2c form a row in the length direction of the columnar body and are arranged at equal intervals. The magnet 2c may be a permanent magnet or the like. Further, a fixing hole 2d used when assembling the stator 2 to an unillustrated apparatus body (for example, an exposure apparatus for exposing a circuit pattern of a reticle onto a substrate such as a wafer by a projection optical system) is formed in the side wall 2b. Have been. In the example shown in FIG.
When the side wall 2d faces the front, fixing holes 2d are formed at the four corners.

A coil is provided inside the protruding portion 3a of the moving element 3 having a convex cross section. An electric wire guided from both ends of the coil is connected to an electrode 3b attached to an upper plane 3d of the mover 3. A current supply line (not shown) is further connected to the electrode 3b. A current flows through the coil by the current supply line. In addition,
Although the coil is not specifically shown in FIG. 1, the interior of the coil, such as the direction of the coil, is such that the magnetic field excited by the coil moves with respect to the magnetic field formed by the magnet 2 c in the stator 2. The arrangement is such that the child 3 is effective for operation. Also, on the upper plane 3d of the moving element 3,
A screw hole 3e for attaching a table or the like (not shown) is formed.

A groove 2e (first member) having a V-shaped cross section is provided on the upper end surface of the side wall 2d of the stator 2, that is, the surface that comes into contact when the stator 2 is combined with the mover 3.
The column is formed over the length direction. In addition, the movable element 3 is configured to engage with the groove 2e having a V-shaped cross section.
A projection (second member) 3c having a V-shaped cross section is formed.
The projection 3c having a V-shaped cross section is formed over the entire length of the columnar body of the moving element 3. In addition, mover 3
Is made of a non-magnetic material such as aluminum so that it can be moved. Therefore, in this case, the projection 3c having a V-shaped cross section is naturally formed of a nonmagnetic material such as aluminum.

In such a linear motor composed of the stator 2 and the moving member 3, the assembling work of both is performed as follows. That is, the relative position between the protrusions 3a of the mover 3 is roughly set so that the protrusions 3a are inserted into the recesses 2a of the stator 2. Then, as shown in FIG.
The position of the moving element 3 is determined so that the e and the projection 3c are engaged. That is, the groove 2e and the projection 3c function as a positioning member for the stator 2 and the moving element 3. This completes the assembling work of both. At this time, the inner wall surface 2bw of the recess 2a and the wall surface 3aw of the protrusion 3a
It is clear that the distance between the two is exactly the proper value.

As described above, the assembling work of the stator 2 and the moving member 3 can be completed very easily. Also,
Although this is easy, the relative positional relationship between the magnet 2c and the coil, that is, the distance between the two is extremely accurately defined. Therefore, good behavioral performance of the moving element 3 after the completion of the assembly can be expected. When the linear motor 1 is actually used, the movable member 3 is separately provided at a position at an appropriate distance from the stator 2 by some means, and the groove 2e and the projection 3c are separated from each other. Used in the state. At this time, the projection 3c
Is formed of a non-magnetic material as described above, the separation between the projection 3c and the groove 2e can be easily performed. Note that a protrusion having a V-shaped cross section may be provided on the stator 2, and a groove having a V-shaped cross section may be provided on the mover 3 to engage with the protrusion.

A second embodiment of the present invention will be described below with reference to FIG. Since the shapes of the stator and the mover, the arrangement of the magnets, the interior of the coil, and the like are the same as those described above, the description thereof will be omitted below.
In FIG. 3, screw holes 40 and 41 are formed in the side surfaces 20a and 30a of the stator 20 and the movable member 30, respectively. In addition, separately from the stator 20 and the mover 30,
A fixed plate (positioning member) 42 made of a nonmagnetic material such as aluminum is prepared. As shown in FIG. 3, two sets of these are prepared. Fixing plate 42
Is a plate-like member having screw holes 42a and 42b formed at both ends. When these screw holes 42a and 42b are arranged so that the fixing plate 42 straddles the screw holes 40 and 41,
The screw holes 40 and 41 are formed so that their relative positions match. The fixing plate 42 is provided with the above-mentioned matched screw holes,
That is, by screwing the screw 50 into the screw hole 42a and the screw hole 40 and the screw hole 42b and the screw hole 41, the relative positional relationship between the stator 20 and the moving member 30 can be fixed.

In the linear motor 10 having the above structure, the operation of assembling the stator 20 and the moving member 30 is performed by the fixing plate 42.
Are arranged so as to straddle the screw holes 40 and 41, and these need only be fastened with screws 50 (not shown) through the screw holes 42a and 42b. Therefore, as in the first embodiment, the assembling work of the two can be completed very easily. It is also clear that accuracy is not compromised, although easy. When the linear motor 10 is actually used, the fixing plate 42 is removed and used. Since the fixing plate 42 is a non-magnetic material, it does not hinder removal from the stator 2.

The third embodiment of the present invention will be described below with reference to FIG. As shown in FIG. 4, a groove 201 and a groove 302 are formed on both surfaces of the stationary member 200 and the movable member 300 which are in contact with each other when the stator 200 and the movable member 300 are combined, over the entire length of the columnar body. I have. Further, separately from the stator 200 and the movable element 300, these grooves 201
A plate member (positioning member) 400 made of a non-magnetic material that engages with the groove 301 is prepared.

The assembling work of the stator 200 and the moving member 300 having such a configuration is completed only by engaging the plate member 400 with the grooves 201 and the grooves 301 formed on the contact surfaces thereof. Will be. In this case, the groove 201
The groove 301 and the plate member 400 function as positioning members in the present embodiment. Therefore, the assembling work of both can be easily performed by this, and the accuracy required for the work is not spoiled. The removal of the plate member 400 during the actual use of the linear motor 100 is the same as that of the fixing plate 42 in the second embodiment. And since this removal was performed because the plate member 400 was a non-magnetic material,
The same can be easily performed.

Hereinafter, supplementary items relating to the present embodiment will be described. In the above-described first to third embodiments, the stator and the mover are used in the vertical type, but the present invention is not particularly limited in this regard. For example, each of the stators 2, 20, 200 and each of the moving elements 3,
Each of 30, 30 may be used as a horizontal type. Although the moving coil type linear motors 1, 10, and 100 have been described above, the present invention can be applied to a moving magnet type linear motor.

In other words, the present invention is not limited to a stator having a concave cross section and a mover having a convex upper cross section. That is, the present invention is applicable to any linear motor in which the relative position between the magnet and the coil needs to be appropriately maintained in the assembling work of the stator and the mover, regardless of the form. Applicable.

FIG. 5 shows a case where the linear motor according to the present embodiment is applied as a substrate stage of an exposure apparatus. As shown in FIG. 5, a stage base SB is mounted on a base B. This stage base S
On B, two sets of linear motors L are installed, each of which is constituted by a plate-shaped stator L2 and a movable member L3 having a U-shaped cross section. Further, the upper surface of each mover L3 and the upper surface of the stage S are connected by a fixing frame FF. The power of the mover L3 is transmitted to the stage S via a fixing frame FF, and can move in the ± Y direction on the stage base SB via an air bearing (not shown). The stage S is provided with a wafer holder WH on which the wafer W is placed. The wafer W is placed on the wafer holder WH by vacuum suction. In the present embodiment, the stator L2 is connected to the stage base S
After being attached to B, the moving element L3 is attached using any of the positioning methods described above.

As shown in the enlarged view of FIG. 6, the linear motor L has a structure in which a pair of magnets (magnetizing bodies) LM are fixed inside the yoke portion L31 of the moving element L3. Further, the stator L2 is formed by fixing a jacket L22 made of tubular stainless steel or aluminum having a rectangular cross section on a stator support L21, and a pair of upper and lower resins adhered to the inside of the jacket L22. A support plate L24 on both sides of which a coil LC is mounted is fixed to the body L23. That is, the linear motor L is of a moving magnet type.

In this case, the assembling work of the stator L2 and the moving element L3 uses the protrusion L2P provided on the upper surface of the jacket L22 and the groove L3G provided on the inner surface of the moving element L3. These projection L2P and groove L3G
Is obviously equivalent to the groove 2e and the protrusion 3c in the first embodiment. Therefore, the assembling operation can be performed while appropriately maintaining the distance between the magnet LM and the coil LC. This contributes to the performance of the stage S such as high-precision positioning. It is needless to say that the work of assembling the stator L2 and the moving element L3 may be performed by using a member similar to the fixed plate 42 and the plate member 400 instead of the protrusion L2P and the groove L3G.

By the way, in the stator L2, the fluid F (for example, water or florinate) flows through the fluid flow path LF formed by the inner wall surface of the jacket L22, and the heat generated from the coil LC is suppressed. Such ingenuity has been made. The symbol FS shown in FIG.
And a fluid temperature controller for adjusting the temperature of the fluid F. Further, in FIG.
Indicates a series of laser measurement equipment for measuring the position of the stage S. When the linear motor of the present embodiment is used for the substrate stage of the exposure apparatus shown in FIG. 5, the stator L2 is controlled so that the reaction force generated when driving the stage S does not affect the exposure of the exposure apparatus.
Is desirably disposed on a separate member that is vibrationally insulated from the stage base SB. In particular, when using a scanning type exposure apparatus that exposes a mask pattern by synchronously moving a mask mounted on a mask stage and a wafer W mounted on a stage S as an exposure apparatus, not only the stage S but also It is desirable that the stator of the linear motor that drives the mask stage is also provided on a separate member that is vibrationally insulated from the mask stage.

The supplementary items according to the first, second and third embodiments will now be described. In the first embodiment, the grooves 2e and the projections 3c do not have to be V-shaped in cross section. That is, any cross section does not depart from the scope of the present invention. In addition, as described above, the groove may be provided on the mover side and the protrusion may be provided on the stator side. In some cases,
The grooves and projections need not be provided over the entire length of the columnar body.

In the second embodiment, the screws 50 are used to fix the fixing plate 42, but the present invention is not limited in this regard. Any member other than the screw 50 may be used as long as it can fix the fixing plate 42, the stator 20, and the movable member 30. At this time, the screw holes 42a and 42b of the fixed plate 42 and the stator 2
0, needless to say, the screw holes 40 and 41 in the moving element 30 also take a form corresponding to the newly adopted positioning member.

In the third embodiment, the plate member 400
Is detachable from either the stator 200 or the moving element 300, but may be fixed to either one of them, depending on the case. That is, in this case, the configuration is substantially the same as that of the first embodiment described for the stator 2 and the movable element 3 having the groove 2e and the projection 3c.

[0031]

As described above, in the linear motor according to the first aspect of the present invention, since the positioning member for positioning the stator and the movable member is provided, the assembling operation of both uses the positioning member. Thereby, it can be accurately and easily implemented. Here, "accurately" means that the assembling operation can be performed while maintaining a proper distance between the magnet and the coil.

According to a second aspect of the present invention, the positioning member has a first member and a second member. For example, as described in the embodiment, the first member corresponds to the groove, and the second member corresponds to the protrusion. This makes it possible to more specifically realize the above-described effects.

Further, the linear motor according to claim 3 is
The other of the positioning members is a non-magnetic material. Therefore, when the linear motor is actually used, the stator and the movable element can be easily separated from each other.

In addition, the linear motor according to claim 4 is
The positioning member is removable. As described specifically in the embodiment, this is realized if the positioning member is, for example, a fixed plate or a plate member, and the positioning member does not hinder the actual use of the linear motor.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an outline of a linear motor according to a first embodiment.

FIG. 2 is a side view showing a state where a stator and a mover are combined in the linear motor shown in FIG. 1;

FIG. 3 is a perspective view showing an outline of a linear motor according to a second embodiment.

FIG. 4 is a perspective view showing an outline of a linear motor according to a third embodiment.

FIG. 5 is an explanatory diagram showing an example in which a linear motor according to the present invention is applied as a stage drive source of an exposure apparatus.

FIG. 6 is an enlarged cross-sectional view of the linear motor shown in FIG.

FIG. 7 is a side view showing a state in which a stator and a mover in a conventional linear motor are combined.

[Explanation of symbols]

 1, 10, 100, L Linear motor 2, 20, 200, L2 Stator 3, 30, 300, L3 mover 2c, LM magnet (magnetizer) LC coil 2e, L3G Groove (first member) 3c, L2P protrusion (Second member) 42 Fixing plate (Positioning member) 400 Plate member

Claims (4)

[Claims] 1. A linear motor comprising a stator and a movable member movable with respect to the stator, wherein a positioning member for positioning the stator and the movable member is provided. motor. 2. The linear motor according to claim 1, wherein said positioning member is a second member capable of engaging with a first member provided on said stator and said first member provided on said mover. And a linear motor having: 3. The linear motor according to claim 2, wherein one of the stator and the mover is a magnet, and the member provided on the other of the stator and the mover is a non-magnetic material. A linear motor, comprising: 4. The linear motor according to claim 1, wherein the positioning member is detachable from the linear motor.