JPH09257106A - Drive device of turn table - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the drive device of a turn table which can stop the turn table at a prescribed position surely and accurately. SOLUTION: A feed drive gear 14 and a return gear 20 meshed with this driven gear 12 are installed on the driven gear 12 for rotating a turn table 10. These gears are stopped after being rotated in a prescribed direction and the front side teeth surface of the feed drive gear 14 is contacted with the rear side teeth surface of the driven gear 12 and also the return gear 20 is rotated in the direction opposite to the prescribed direction and the rear side teeth surface of the return gear 20 is contacted with the front side teeth surface of the driven gear 12 and the minute rotation of the driven gear 12 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device for a rotary table, and more particularly to a backlash removing device for a feed drive gear device that rotates a rotary table of a vacuum processing device.

[0002]

2. Description of the Related Art Generally, a vacuum processing apparatus is used to form a thin metal film on the surface of a disk-shaped object to be processed such as a CD. FIG. 4 shows an example of a conventional vacuum processing apparatus 1 of this type. A vacuum transfer chamber 3 is formed inside the housing 2 having a substantially octagonal shape in plan view, a lid (not shown) is provided on the top of the housing 2 to close the vacuum transfer chamber 3, and a turbo molecular pump (not shown) is provided at the bottom. Provided and vacuum transfer chamber 3
There is a vacuum atmosphere inside.

On the other hand, a load lock chamber 4 for loading and unloading the workpiece W is provided on one side of the octagonal shape of the vacuum transfer chamber 3, and vacuum processing chambers 5a and 5a are provided on the remaining sides, respectively.
b ... 5g are provided. Further, the load lock chamber 4 and the walls of the respective vacuum processing chambers 5 on the side of the vacuum transfer chamber 3 are formed with openings 6 for loading and unloading the workpiece W, respectively. A valve disc 7 is provided in each opening 6 so that it can be opened and closed. By closing the valve disc 7 with a valve opening / closing mechanism 8, the vacuum transfer chamber 3 and the load lock chamber 4 are closed.
And the airtightness between each vacuum processing chamber 5 is maintained. Then, the workpiece W carried into the load lock chamber 4 and held on the valve disc 7 is successively carried into the respective vacuum processing chambers 5 by the rotary table 10 which is rotated by the drive device 9, and each of these is carried out. In the vacuum processing chamber 5, operations necessary for forming a thin film such as etching and baking on the object W to be processed are continuously performed.

In the figure, reference numeral 11 indicates a turbo molecular pump. The lower part of the rotary table 10 is shown in FIG.
As shown in, the driven gear 12 is fixed, and the rotary table 10 is rotated within a predetermined angle range by meshing the driven gear 12 with the drive gear 14 driven by the motor 13. Further, according to another conventional example, as shown in FIG. 6, the driven pulley 15 under the rotary table 10 is used.
Is mounted, the belt 18 is wound between the driven pulley 15 and the drive pulley 17 driven by the motor 16, and the rotary table 10 is rotated.

[0005]

In the conventional example shown in FIG. 5, the backlash 19 due to the tooth profile error and pitch error of the gear as shown in FIG. 7 cannot be avoided. Therefore, the rotary table 10 rotates within the range of the backlash 19 by the inertial force of the rotary table 10,
There is a problem that it is difficult to stop the rotary table at an accurate position. Then, when the rotary table 10 shifts from a predetermined position and stops, the position of the valve disc 7 to the opening 6 of the vacuum transfer chamber 3 and the load lock chamber 4 and the vacuum processing chamber 5 shifts to open and close the valve disc 7. There is a problem in that the smoothness cannot be achieved, and the variation in the film thickness distribution becomes large when a thin film is formed on the object W to be processed. Further, according to the conventional example shown in FIG. 6, it is difficult to obtain a large rotation ratio, and it is necessary to provide a certain axial distance between the drive pulley 17 and the driven pulley 15, so that the device becomes large. There was a problem such as.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above problems of the prior art and to provide a rotary table drive device capable of accurately and reliably stopping the rotary table at a predetermined position.

[0007]

To achieve the above object, the present invention provides a drive gear, a driven gear that is fixed to a rotary table and meshes with the drive gear, and a return gear that meshes with the driven gear. Provided with, the drive gear that rotates in a predetermined rotation direction, while stopping the rotation of the driven gear and the return gear to bring the front tooth surface of the drive gear into contact with the rear tooth surface of the driven gear, The return gear is rotated in a direction opposite to a predetermined rotation direction so that a rear tooth surface of the return gear is brought into contact with a front tooth surface of the driven gear.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A case in which a rotary table driving device according to the present invention is applied to a rotary table of a vacuum processing apparatus will be described below with reference to FIGS. The drive device 9 for rotating the rotary table 10 in the forward direction includes a feed drive gear 14 and a drive motor 13 for the feed drive gear 14.
, Driven gear 12, return gear 20, and return gear 2
Drive motor 21 of 0. The driven gear 12 is
It is fixed to the center of the lower portion of the rotary table 10, and a feed drive gear 14 meshes with the driven gear 12. A return gear 20 meshes with the feed drive gear 14 at a position away from the feed drive gear 14. The rotation torque of the return gear 20 is about 1/10 of the rotation torque of the feed drive gear 14.

Since the drive unit 9 is constructed as described above, when the feed drive gear 14 is rotated in the P direction in FIG. 2, the driven gear 12 and the return gear 20 are also rotated in the P direction. When the rotary table 10 rotates and the valve disk 7 holding the workpiece W comes in front of the opening 6 of the vacuum processing chamber 5, the drive motor 13 of the feed drive gear 14 stops rotating, and the feed drive gear 14 front tooth surface 22 and driven gear 1
As shown in FIG. 3, the rear tooth surface 23 of 2 is in contact with the tooth surface 23. In order to maintain this state, the drive motor 21 of the return gear 20 rotates in the reverse direction, and the return gear 20 rotates in the Q direction shown in FIG. Then, the rear tooth surface 24 of the return gear 20 comes into contact with the front tooth surface 25 of the driven gear 12, and the driven gear 12 has an R
The rotational torque in the direction is applied, and the rotational torque from the feed drive gear 14 and the return gear 20 acts on the driven gear 12, and the driven gear 12, that is, the rotary table 10 is completely stopped. In this case, since the feed drive gear 14 has a larger holding torque than the return gear 20,
The rotation of the return gear 20 does not rotate the driven gear 12. Therefore, the workpiece W held on the valve disc 7 can be stopped at the correct position with respect to the opening 6 of each vacuum processing chamber 5, and each vacuum processing chamber 5 of the workpiece W can be stopped. It can be carried in smoothly, and the variation in the film thickness distribution when forming a thin film can be minimized.

[0010]

As is apparent from the above description, according to the present invention, the feed drive gear and the return gear mesh with the driven gear provided on the rotary table, and the feed drive gear rotates in a predetermined direction. , The rotation of the driven gear and the return gear is stopped to bring the front tooth surface of the feed drive gear into contact with the rear tooth surface of the driven gear, and the return gear is rotated in the opposite direction to the predetermined rotation direction to return. Since the rear tooth flank of the gear is brought into contact with the front tooth flank of the driven gear, the rotation of the rotary table can be stopped quickly, reliably and accurately at any rotation angle.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a rotary table driving device according to the present invention.

FIG. 2 is an explanatory view showing a meshed state of gears.

FIG. 3 is an explanatory view showing a meshed state of gears.

FIG. 4 is a perspective view of a vacuum processing apparatus to which the rotary table driving device according to the present invention is applied.

FIG. 5 is a perspective view of a drive device that drives a conventional rotary table.

FIG. 6 is a perspective view of another drive device that drives a conventional rotary table.

FIG. 7 is an explanatory diagram showing a meshed state of gears.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum processing device 3 Vacuum transfer chamber 4 Load lock chamber 5 Vacuum processing chamber 7 Valve disc 9 Drive device 10 Rotary table 12 Driven gear 14 Feed drive gear 19 Backlash 20 Return gear

Claims (1)

[Claims] 1. A drive gear which is provided with a drive gear, a driven gear which is fixed to a rotary table and which meshes with the drive gear, and a return gear which meshes with the driven gear, and which rotates in a predetermined rotation direction. Stop the rotation of the driven gear and the return gear to bring the front tooth surface of the drive gear into contact with the rear tooth surface of the driven gear, and rotate the return gear in a direction opposite to the predetermined rotation direction. The drive device for the rotary table is characterized in that the rear tooth surface of the return gear is brought into contact with the front tooth surface of the driven gear to prevent rotation of the driven gear.