KR100904345B1 - Surface stage - Google Patents

Abstract

The present invention is a planar stage in which a moving object is moved on a platen provided with convex poles in a lattice shape, so that the moving object can be linearly moved in the XY direction while the moving object is rotated.

The Y-direction movers 20c and 20d are provided at two places on the X axis of the mover 30 and are attached to the mover 30 via the rotary bearing 24. The movers 20a and 20b for the X-direction movement are mounted to the plate 25 and to the moving body 30 through the rotary bearing 26. To move the movable body 30 in the XY direction, the movers 20a and 20b or the movers 20c and 20d are moved in the same direction. When the moving body 30 is rotated, the movers 20c and 20d are moved in the reverse direction. When the moving body 30 is rotated, the magnetic poles of the moving parts 20a to 20d rotate to follow the direction of the convex pole of the platen 10, and in this state, the moving body 30 can be moved in the XY direction.

Description

Planar Stage {SURFACE STAGE}

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing the configuration of a planar stage in an embodiment of the invention.

2 is a view showing a state in which the moving object is rotated θ in the planar stage of the embodiment of the present invention.

3 is a view showing a modification 1 of the planar stage of the embodiment of the present invention;

4 is a view showing a modification 2 of the planar stage of the embodiment of the present invention.

5 is a view showing a modification 3 of the planar stage of the embodiment of the present invention.

Fig. 6 is a view showing a modification 4 of the planar stage of the embodiment of the present invention.

7 is a view for explaining the principle of operation of a conventional planar stage.

8 is a view for explaining the principle of operation of a conventional planar stage.

9 is a timing chart of current flowing through the coil of the magnetic pole in the planar stages shown in FIGS.

FIG. 10 is a diagram showing a specific configuration example of the mover shown in FIGS. 7 and 8; FIG.

Fig. 11 is a diagram showing the configuration of a conventional planar stage in which four movers are provided in the moving body.

It is a figure explaining the case where (theta) rotates a planar stage.

FIG. 13 is a view showing a state of a magnetic pole when the movable body is rotated θ in FIG. 11. FIG.

<Explanation of symbols for main parts of drawing>

10: platen 10a: nonmagnetic material

11 to 17: convex pole 20, 20a to 20d: mover

21 permanent magnet 22a to 22d magnetic pole

23a, 23b: coil 24: rotating bearing

25 plate 26 rotating bearing

30: moving body 40: air pad

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar stage on which a moving body moves on a platen, and more particularly, to a planar stage capable of smoothly moving in a XY direction in a state in which the moving stage on a platen is rotated θ.

Conventionally, a moving body is floated on a flat platen having a convex pole of a lattice-shaped ferromagnetic material by air, a magnetic force is applied to the moving body, and the moving body is changed by changing the magnetic force between the moving body and the convex pole of the platen. The planar stage apparatus comprised so that it is moved is known (for example, refer patent document 1).

In the planar stage, one surface of the movable body is planarized with high precision in order to be a work stage for placing the workpiece. The other surface is provided with a magnetic pole for generating a moving magnetic field in each axial direction of the orthogonal coordinate axis and an air pad for blowing air.

To face the convexity of the platen, the magnetic pole of the mobile body and the air pad are placed, and the mobile body floats by the action of air. In this state, a moving magnetic field is generated on the magnetic pole of the moving object, and the moving object moves on the platen by changing the magnetic field between the magnetic pole and the convex pole of the platen.

Moreover, the apparatus which has such a structure is called a surface motor stage apparatus, a Sawyer motor stage apparatus, etc. in some cases.

Unlike a stage device having a configuration using a conventional ball screw, such a planar stage device XY a moving body on one stage made of a flat platen without overlapping the X stage, the Y stage, and the θ stage with a plurality of stages. Direction and θ rotation.

Therefore, in recent years, application as a work stage of a step and repeat exposure apparatus which moves and divides the workpiece | work divided into the some exposure area | region in the order of the divided area | region is examined. In the exposure apparatus using the planar stage apparatus as a work stage, since the structure of a work stage becomes simple, it is anticipated that the weight reduction of an apparatus can be aimed at.

The operating principle of the planar stage will be briefly described with reference to FIGS. 7, 8 and 9. 7 and 8 are cross-sectional views of the platen 10 having a plurality of convex poles constituting the planar stage and the mover 20 having a magnetic pole, and FIG. 9 is a coil wound around the magnetic pole of the mover 20. This is a timing chart of the current flowing in the. 9 represents the direction of current flowing through the coil. In addition, the pattern of the electric current of FIG. 9 is an example, and as shown with a sine wave, you may change a current value smoothly.

The platen 10 has a flat plate shape, and as shown in Fig. 7, the convex poles 11, 12, ... of ferromagnetic material are provided in a lattice shape. Between the convex pole and the convex pole is filled with a nonmagnetic material 10a.

The permanent magnet 21 is attached to the mover 20, whereby the magnetic poles of N or S are generated in the four magnetic poles 22a to 22d provided in the mover in the same figure.

The coils 23a and 23b are wound around the magnetic poles 22a to 22d, and when the current flows, each magnetic pole 22a to 22d becomes an electromagnet. If the magnetic field produced by the permanent magnet 21 and the magnetic field produced by the electromagnet are the same, the magnetic force is strengthened. If the magnetic field produced by the permanent magnet 21 and the magnetic field produced by the electromagnet are reversed, the magnetic force is canceled.

The coils 23a are wound in opposite directions in the magnetic poles 22a and 22b. Therefore, when the magnetic field in the same direction is generated in the magnetic pole 22a and the magnetic force is strengthened, the magnetic force in the opposite direction is generated in the magnetic pole 22b to cancel the magnetic force. The magnetic poles 22c and 22d are also the same.

The magnetic poles 22a to 22d of the mover 20 are placed to face the convex poles 11, 12,... Of the platen 10. The mover 20 is lifted from the platen 10 by the action of a pad that ejects air, but the air pad is omitted in FIGS. 7 and 8.

The upper surface of the mover 20 becomes the surface on which the workpiece is placed. Although the workpiece may be directly placed on the mover 20, the work stage may be placed on the upper surface of the mover 20, and the workpiece may be placed thereon.

From the drive circuits not shown in each of the coils 23a and 23b wound around the magnetic poles 22a to 22d, a moving magnetic field is generated by flowing a current in the following order, and the mover 20 moves in the left and right directions in the figure. . Hereinafter, an operation principle in which the mover 20 moves in the right direction of the drawing will be described.

(1) STEP 1: Current flows through the coil 23a on the magnetic poles 22a and 22b of the mover 20 so as to strengthen the magnetic force of the magnetic pole 22a. No current flows through the coils 23b of the magnetic poles 22c and 22d. Since the magnetic pole 22a becomes stronger, the magnetic pole 22a is strongly attracted to the convex pole 11 of the platen 10, and the magnetic pole 22a and the convex pole 11 are opposed to each other.

The magnetic pole 22b cancels the magnetic force and is located on the nonmagnetic material between the convex poles 12 and 13. The magnetic poles 22c and 22d are attracted to the convex poles 14 and 16 in the inclination direction, respectively.

(2) STEP 2: As shown in FIG. 9, the current of the coil 23a of the magnetic poles 22a and 22b is stopped, and the magnetic force of the magnetic pole 22d is applied to the coil 23b of the magnetic poles 22c and 22d. Current to strengthen. The magnetic poles 22d strongly attract each other with the convex poles 16, and the magnetic poles 22c cancel the magnetic force and do not attract each other with the convex poles 14.

Thus, the mover 20 moves in the right direction in the same drawing so that the magnetic pole 22d faces the convex pole 16. The magnetic poles 22a and 22b are attracted to the convex poles 11 and 13 in the inclination direction, respectively.

(3) STEP 3: As shown in FIG. 9, the current of the coil 23b of the magnetic poles 22c and 22d is stopped, and this time to the coil 23a of the magnetic poles 22a and 22b, this time of the magnetic pole 22b. Current flows to strengthen the magnetic force. The magnetic poles 22b are strongly attracted to the convex poles 13, and the magnetic poles 22a cancel their magnetic forces so that the magnetic poles 22a are not attracted to each other.

The mover 20 moves in the right direction in the drawing so that the magnetic pole 22b faces the convex pole 13.

(4) STEP 4: As shown in FIG. 9, the current of the coil 23a of the magnetic poles 22a and 22b is stopped, and the magnetic force of the magnetic pole 22c is applied to the coil 23b of the magnetic poles 22c and 22d. Current to strengthen. The magnetic poles 22c strongly attract each other with the convex poles 15, and the magnetic poles 22d cancel the magnetic force and do not attract each other with the convex poles 16. FIG. The mover 20 moves in the right direction in the drawing so that the magnetic pole 22c faces the convex pole 15.

In addition, after moving to the position of STEP 4, as shown in STEP 4 of FIG. 9, the mover 20 can be hold | maintained in the position of STEP 4 by continuing to flow a current through the coil 23b.

10 (a) and 10 (b) are views showing a specific configuration example of the mover 20, the figure (a) is a view of the mover 20 viewed from the side, and the figure (b) is a platen It is the figure seen from the surface side opposite to.

As shown in the figure, the magnetic poles 22a to 22d of the mover 20 are composed of a plurality of smaller convex poles.

As shown in the drawing (a), when the interval between the convex poles formed on the platen 10 is a, the interval between the convex poles formed on the magnetic poles 22a to 22d is a, and the magnetic poles 22a and 22b are respectively. The interval between the magnetic poles 22c and 22d is 2a, and the interval between the magnetic poles 22b and 22c is 2.5a. That is, as shown in FIG. 7, above, when the magnetic poles 22a and 22b face the convex poles of the platen 20, a part of the magnetic poles 22c and 22d (1/2 in this example) is flat. It faces the convex pole of the tongue 10.

Fig. 11 is a diagram showing the configuration in the case where four movers 20a to 20d are provided on the moving body 30 such as a work stage so as to be able to move in the orthogonal XY direction, and Fig. 11 (a) is a platen ( 10) FIG. 11B is a view of the movable body 30 moving upward from the surface side opposite the platen 10. FIG. 11 (b) shows the movable body 30 in a direction parallel to the plane of the platen 10. In the PP direction). In addition, although the mover 20 is shown as a continuum of convex poles in the same figure, it has the structure shown in the said FIG. 7, FIG. 8, FIG. 11 (b), the convex poles provided on the platen 10 are omitted.

As shown in FIG. 11 (a), air pads 40 for ejecting air are provided at four corners of the movable body 30. Air blown out from the air pad 40 touches the surface of the platen 10, and the movable body 30 floats with respect to the platen 10.

The movers 20a to 20d are provided at four locations in the XY direction perpendicular to the center of the mover 30. The movers 20a and 20b are movers for moving the mover 30 in the X direction (left and right directions in FIG. 11), and are provided at two locations (up and down in the figure) on the Y axis. The movers 20c and 20d are movers for moving the mover 30 in the Y direction (up and down direction in Fig. 11), and are provided at two locations (left and right in the figure) on the X axis.

Each of the movers 20a to 20d has the configuration shown in FIG. 10, and a magnetic field for moving in the left and right directions is generated in the magnetic pole of the mover 20a for moving in the X direction, so that both movers 20a and 20b If the moving direction of the magnetic field in () is the same, the moving body 30 moves in the X direction.

Moreover, if the magnetic field for moving to the up-down direction generate | occur | produces in the mover 20c, 20d for Y direction movement, and the moving direction of the magnetic field in both movers 20c, 20d is the same, the movable body 30 will be Y. Move in the direction of

When using the stage which has such a moving body 30 as a work stage of a sequential exposure apparatus, only the movement in an XY direction is insufficient, and as shown to FIG. 12 (a), the pattern formed in the workpiece | work W When (P) causes a position shift in the θ rotation direction, in order to perform alignment with this, as shown in Fig. 12B, the stage is rotated around an axis perpendicular to the stage surface (such rotation). Hereinafter referred to as θ rotation).

In order to rotate the movable body θ, for example, the moving direction of the magnetic field of the movers 20c and 20d of the movable body 30 is reversed. In this case, since the moving directions are reversed on the mover 20c side and the mover 20d side of the mover 30, the mover 30 rotates θ as shown in FIG. 12. Even if the moving direction of the magnetic fields of the movers 20a and 20b is in the reverse direction, the movable body 30 can be rotated θ similarly.

<Patent Document 1> Japanese Unexamined Patent Publication No. 9-23689

Such a planar stage has a drawback in that it cannot move linearly in the X or Y direction while maintaining the state in which the movable body is rotated θ. The reason is as follows.

As shown in the prior art, the magnetic poles installed in the mover and the convex poles of the platen are in a predetermined positional relationship and move so that this positional relationship is repeated.

For example, in FIG. 7, the magnetic pole 22a provided in the mover 20 faces the convex pole 11 of the platen 10, and the magnetic pole 22b faces the nonmagnetic material of the platen 10. The magnetic poles 22c and 22d correspond to the intermediate positions of the convex poles 14 and 16 and the nonmagnetic material of the platen 10, and the mover 20 moves linearly by moving the relationship between the magnetic poles and the convex poles. do.

However, when the movable body 30 rotates θ as described above, the alignment direction of the magnetic poles 22a to 22d of the movers 20a to 20d and the alignment direction of the convex poles of the platen 10 are not parallel (or orthogonal). (Hereinafter, orthogonal collapse is called this state).

That is, as shown in FIG. 13, the state in which the movable body 30 is rotated θ is a state in which orthogonalities of the magnetic poles and the convex poles collapse, and are shifted from the predetermined positional relationship. If the linear movement is attempted while maintaining the state, the driving force for the movers 20a to 20d is lowered, so that the controllability to the movers 20a to 20d is deteriorated, making it difficult to align the set position.

As mentioned above, in the structure shown in FIG. 11, when linear movement is normally performed after (theta) rotation, linear movement is made after returning (theta) rotation to original.

That is, in order to linearly move the moving body 30 after θ rotation, the convex poles of the movers 20a to 20d and the convex poles of the platen 10 are orthogonal to each other by returning θ rotation to its original position, and the mover 20a to 20b) and the convex pole of the platen 10 are made to be in the predetermined positional relationship, and then moved.

As described above, it is considered to employ the planar stage shown in FIG. 11 as the work stage of the exposure apparatus sequentially. In the sequential exposure apparatus, as shown in FIG. 12, alignment in the (theta) direction is performed in a certain exposure area | region, and moving and exposing to the exposure area of an X or Y direction, maintaining the state is performed.

In order, [theta rotate position] → [exposure] → [move to X (or Y) direction] → [exposure] → [move to X (or Y) direction]. Becomes

By the way, if this is to be done in the planar stage, it is difficult to move the movable body 30, which is the stage on which the work is placed, in the XY direction while maintaining the θ rotation as described above. [Exposure] → [theta rotate back] → [the shift in X (or Y) direction] → [theta rotate the rotation position] → [exposure] → [theta rotate back] → [the shift in X (or Y) direction]. Will be moved to.

That is, the θ-rotation return and θ-rotation position of the moving object 30 must be performed for each movement in the XY direction, and the entire exposure processing time becomes longer than when the flat stage is not used.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and an object of the present invention is to provide a plate-like platen having a plane in which a convex pole is provided in a lattice shape, and a moving magnetic field in each axial direction of an orthogonal coordinate axis. It is provided with a moving body provided with a moving object for generating a, and in a flat stage apparatus in which the moving object moves on the platen plane, it is an object to enable the moving body to move linearly in the XY direction while maintaining the θ rotation.

Conventionally, although the mover is fixed with respect to the moving body, the mover is fixed with respect to the moving body so as to have a degree of freedom in the rotational direction (freely rotated) with respect to the geometry center of the mover. Specifically, the magnetic pole is fixed to the movable body through the rotary bearing.

In the position where the magnetic pole is mounted, magnetic poles for Y-direction movement are provided on both sides of the movable body. The magnetic pole for X direction movement is attached to the straight line which arises by connecting the rotation center of the magnetic pole for Y direction movement.

1 is a diagram showing the configuration of a planar stage in an embodiment of the present invention.

Fig.1 (a) is a figure which looked at the moving body from the surface side which opposes a platen, and FIG.1 (b) is a figure which looked at the moving body from the direction parallel to the platen plane (P-P direction of the same figure). In addition, the air pad 40 is abbreviate | omitted in FIG.1 (b). In addition, the platen 10 has a flat plate shape as described above, a convex pole of a ferromagnetic material is provided in a lattice shape, and a gap between the convex pole and the convex pole is filled with a nonmagnetic material.

The Y-direction movable movers 20c and 20d for moving the movable body 30 in the Y direction have the structures shown in FIGS. 7, 8 and 10, and as shown in FIG. It is provided in two places on a X axis (left and right in a figure). However, the movers 20c and 20d are rotatably mounted via the rotary bearing 24 with the geometric center as the rotation axis.

Although the X-direction movable movers 20a and 20b for moving the movable body 30 in the X-direction also have the structures shown in Figs. 7, 8 and 10, in the present embodiment, the movers 20a and 20b, It is attached to one plate 25. The plate 25 is mounted to the movable body 30 through the rotary bearing 26.

The geometric center of the plate 25 on which the movers 20a and 20b are mounted coincides with the midpoint of the straight line formed by connecting the rotation centers of the movers 20c and 20d for the Y-direction movement, and the rotary bearing 26 is positioned at that position. The plate 25 is rotated with the center as the rotation axis.

In addition, the said rotary bearing 24 does not necessarily need to be installed in the midpoint on the straight line which connects the rotation centers of the Y-direction movers 20c and 20d, and may shift from the midpoint position if it is on this straight line.

In this case, the rotation center at the time of rotating the moving body 30 becomes a position which provided the said rotary bearing 26. As shown in FIG. For this reason, each movement amount of the Y-direction movement movers 20c and 20d at the time of rotating the moving body 30 is set so that the said position may become a rotation center.

The air pad 40 is provided in three places of the moving body 30, as shown to FIG. 1 (a). Since the plane is positioned at three points, even if it is not provided in four places as shown in FIG. 10, the stability is good and the movable body 30 can be supported with respect to the platen 10.

The operation of the movable body 30 of the present embodiment will be described.

(1) Movement of the Moving Body 30 in the XY Direction

 In order to move the movable body 30 in the X direction, the current flows in the same order as the coil wound around the magnetic poles of the X-direction movable movers 20a and 20b as described above with reference to FIGS. 7 and 8. Thereby, when the moving magnetic field of the left-right direction of FIG.1 (a) generate | occur | produces, and the moving direction of a moving magnetic field is the same, the mover 20a, 20b will move to an X direction, and the moving body 30 will move to an X direction. If the movers 20a and 20b are moved at the same speed by the same amount, the mover 30 moves in the X direction without rotating θ.

The same applies to the case where the movable body 30 is moved in the Y direction, and if the moving directions of the movable members 20c and 20d in the Y direction mounted on the plate 25 are the same, the movable body 30 moves in the Y direction.

Here, since the plate 25 is attached to the movable body 30 via the rotary bearing 26, even if the movers 20a and 20b are moved in the reverse direction, only the plate 25 rotates and the movable body ( 30) neither rotate nor move. When the movers 20a and 20b are moved in different amounts in the same direction, the mover 30 moves in the direction, but the magnetic poles of the movers 20a and 20b and the convex poles of the platen 10 are moved. The orthogonal to collapses, and the driving force falls.

In addition, after moving the movable body 30, in order to keep the movable body 30 in that position, it continues to flow as it is, without stopping the electric current which flows to the coil of the movable bodies 20a-20d as mentioned above.

(2) Movement of θRotation and θRotation of Moving Body 30

To rotate the movable body 30, as described in Fig. 11, the movers 20c and 20d are moved in the reverse direction, with the moving direction of the moving magnetic field of the movers 20c and 20d for the Y direction reversed. As a result, the movable body 30 rotates θ.

Further, even if the moving directions of the movers 20c and 20d are the same, if the moving amounts are different, the moving body 30 moves in the Y direction while rotating θ.

Since the movers 20c and 20d are free to rotate with respect to the mover, when the mover 30 rotates θ, as shown in FIG. 2, the mover 20c and 20d rotates with respect to the mover 30 but the platen ( It does not rotate with respect to 10), and the magnetic poles of the movers 20c and 20d are orthogonal to the convex poles of the platen 10.

In the [theta] rotation of the movable body 30, the coil of the magnetic pole of the X-direction movable movers 20a and 20b is not related to the [theta] rotation caused by the movement of the Y-direction movers 20c and 20d.

However, the plate 25 on which the movers 20a and 20b are mounted is free to rotate with respect to the mover 30. Therefore, when the movable body is rotated θ, the plate 25 is rotated by the magnetic poles of the movers 20a and 20b and the suction force of the convex poles of the platen 10, and is orthogonal to the convex poles of the platen 10. It remains natural.

That is, even if the movable body 30 is rotated θ, the magnetic poles of the respective movableers 20a to 20d are not orthogonal to the platen 10, so that the movable body 30 does not rotate and basically does not change. .

In other words, even when the movable body 30 is rotated θ, the magnetic poles of the respective movableers 20a to 20d can maintain a predetermined relationship with respect to the convex pole of the platen 10.

Therefore, in this state, when the magnetic field is moved in the same direction in the movers 20a and 20b for the X-direction movement, the movable body moves in the X direction. In the Y-direction moving movers 20c and 20d, when the magnetic field is moved in the same direction, the movable body 30 moves linearly in the Y direction.

In order to realize the above-mentioned operation, it is necessary to provide the X-direction moving movers 20a and 20b and the Y-direction moving movers 20c and 20d with respect to the movable body 30 so as to satisfy the following conditions.

(A) Both the X-direction moving movers 20a and 20b and the Y-direction moving movers 20c and 20d have a center of rotation at the geometric center thereof.

(B) On the straight line formed by connecting the rotation centers of the two Y-direction movers 20c and 20d, there are rotation centers of the X-direction movers 20a and 20b.

In addition, if the rotation center of the X-direction movement movers 20a and 20b is placed at the midpoint on the straight line formed by connecting the rotation axes of the two Y-direction movers 20c and 20d, the Y-direction movers 20c and 20d are reversed. By moving the same amount in the direction, the movable body 30 can be rotated θ about the midpoint.

If the above conditions are satisfied, it is also conceivable to arrange the movers 20a to 20d on the mover 30 as shown in Figs.

As shown in FIG. 3, the rotation centers of the X-direction moving movers 20c and 20d are positioned at positions shifted from the center of the moving body 30.

In addition, the two bearings 20A and 20b for moving in the X direction are not mounted on the plate 25, but as shown in FIG. 4, the rotary bearing 26 is provided in the geometric center of one mover 20e. The mover 20a is attached to the mover 30 through this rotary bearing.

In addition, as shown in FIG. 5, the Y-direction moving movers 20c and 20d may be mounted in the inclination direction (diagonal direction) with respect to the moving body 30.

In addition, as shown in Fig. 6, the centers of rotation on the straight lines formed by connecting the rotation centers of the two Y-direction movers 20c and 20d do not need to have the rotation centers of the X-direction movers 20a and 20b. In the case of the configuration as shown in Fig. 6, when the movable body 30 is rotated θ, the movement amounts d1 and d2 of the moving members 20c and 20d for the Y-direction movement are set to be d1 / d2 = L1 / L2. do. Here, L1 and L2 are distances between the mover 20c and the centers P1 and P2 of the mover 20d and the rotational center θ. By moving the movers 20c and 20d for the Y-direction movement in the reverse direction d1 and d2, the movable body 30 can be rotated θ about the rotation center θ.

In the present invention, the magnetic pole is fixed to the movable body with a degree of freedom in the rotational direction (freely rotated) at the center of the geometry of the magnetic pole. Therefore, even if the movable body rotates, the magnetic pole of the movable body can be kept perpendicular to the convex pole of the platen. , Can move linearly in XY direction.

Claims (1)

A planar stage device comprising: a moving object including a mover having a magnetic pole for generating a moving magnetic field on each of the XY coordinate axes orthogonal to the platen plane on a planar platen provided with convex poles in a lattice shape; The mover having a magnetic pole generating a moving magnetic field in each of the axial directions, Two Y-direction movable movers having magnetic poles for generating a moving magnetic field in the Y-axis direction of the coordinate axis, rotatably mounted on both sides of the movable body; An X-direction movement mover having a magnetic pole for generating a moving magnetic field in the X-axis direction of the coordinate axis freely mounted on a straight line formed by connecting the rotation centers of the two Y-direction movers, And the direction of arrangement of the magnetic poles of the Y-direction moving mover and the magnetic poles of the X-direction moving mover is parallel to the direction of alignment of the convex poles of the platen even when the moving body is rotated.

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