JPH0541143U - XY moving table drive mechanism - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize an XY moving table drive mechanism that is compact and does not require a large space without backlash. When the rotating shaft 21 is rotated, the rotation of the rotating shaft 21 is transmitted to a screw gear 22 via a ball spline mechanism 24, and the rotation of the screw gear 22 is transmitted to the screw gear 20. The rotation of the screw gear 20 causes the feed screw 8 to rotate, which causes the ball screw 7 to linearly move on the feed screw 8 to move the X-movable table 6
Can be moved vertically in the figure. When the Y moving table 3 is moved in the left-right direction in the drawing by driving from the same direction as the rotary shaft 21, the housing 23 moves in the left-right direction together with the Y moving table 3. Therefore, the screw gear 22 inside the housing 23 and the screw gear 2 at the tip of the feed screw
The meshing with 0 does not come off even if the Y moving table 3 moves.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an XY moving table driving mechanism which is optimal for moving a semiconductor wafer sample in both X and Y directions by a scanning electron microscope or the like.

[0002]

[Prior Art]

 FIG. 2 shows an XY moving table mechanism in a conventional scanning electron microscope or the like. Reference numerals 1 and 2 denote Y-movement rails, and the Y-movement table 3 is moved in the left-right direction in the figure by being guided by the rails 1 and 2. Although not shown, a mechanism for linearly moving the Y moving table 3 from the right side of the figure, for example, a ball screw that moves integrally with the Y moving table 3 and a feed screw that meshes with the ball screw. Is provided. Then, by rotating the feed screw, the ball screw and the Y moving table 3 are integrally moved in a straight line in the left-right direction. X movement rails 4 and 5 are fixed on the Y movement table 3, and the rails 4 and 5 are arranged at right angles to the Y movement rails 1 and 2. An X motion table 6 is guided by the X motion rails 4 and 5 and moved in the vertical direction in the figure. Although not shown, a sample for the scanning electron microscope or a sample holder is placed on the X-moving table 6. A ball screw 7 is fixed to the X-moving table 6, and the ball screw 7 is meshed with a feed screw 8 arranged in parallel with the X-moving rails 4 and 5. A bevel gear 9 is provided at one end of the feed screw 8, and the bevel gear 9 is screwed with a bevel gear 11 at the tip of a rotary shaft 10. One end portion of the rotary shaft 10 is inserted into the rotary sleeve 12, and the shaft 10 is configured to be movable in the left-right direction in the drawing together with the Y moving table 3 by a joint member 13. There is. That is, the joint portion between the joint member 13 and the shaft 10 is such that the shaft 10 can freely rotate within the joint member 13, but the shaft 10 also moves together with the linear movement of the joint member 13. It is configured. The rotation of the rotating sleeve 12 is transmitted to the shaft 10, but the inside of the sleeve 12 and the shaft 10 are joined so that the shaft 10 can move linearly with respect to the sleeve 12. The operation of such a configuration will be described below.

The Y moving table 3 is linearly moved in the left-right (Y) direction in the drawing by rotating a feed screw (not shown). At this time, the joining member 13 moves integrally with the movement of the Y moving table 3, and as a result, the shaft 10 joined to the joining member 13 also moves in the same direction as the Y moving table 3. Therefore, the bevel gear 11 at the tip of the shaft 10 and the bevel gear 9 at the tip of the X-moving feed screw 8 fixed on the Y moving table 3 are always in mesh with each other even when the Y moving table 3 is moved. R. When the X-movement table 6 is moved, the shaft 12 is rotated by rotating the sleeve 12, and the rotation of the shaft 10 is transmitted to the X-movement feed screw 8 via the bevel gears 11 and 9. The rotation of the feed screw 8 moves the ball screw 7 in the vertical (X) direction in the figure, and the X-movable table that moves integrally with the ball screw 7 is also moved in the X direction.

[0004]

[Problems to be solved by the device]

 In the above-mentioned configuration, when two X and Y tables are moved, both tables are driven from the same direction (right side in the figure). Such a drive mechanism is used for a sample such as a scanning electron microscope. When used for movement, it is convenient because the X and Y movement control can be performed from the same position. However, in order to move the X and Y in the orthogonal direction from the same position (direction), it is necessary to convert the rotation axis by 90 ° and transmit it to either one of the X and Y. Therefore, in the above drive mechanism, the rotating shaft is converted by 90 degrees by the bevel gears 9 and 11, and the shaft 10 having the bevel gear 11 at its tip can be moved integrally with the Y moving table 3. There is. The shaft 10 is inserted into the sleeve 12 so that the shaft 10 can move linearly. Therefore, there is a drawback that backlash due to the sleeve mechanism is likely to occur. Further, in order to convert the rotating shaft by 90 degrees by the bevel gear, the rotating mechanism including the shaft 10 and the sleeve 12 and the X-motion feed screw 8 must be at the same height. For this reason, the movement of the X-moving table 6 interferes with the movement of the sleeve mechanism, and in order to prevent this interference, the space between the X-moving table 6 and the sleeve mechanism must be increased. Further, the sleeve mechanism also requires each component to be longer than the movement stroke of the Y-movable table 3, which also increases the size of the entire configuration.

The present invention has been made in view of the above circumstances, and an object thereof is to realize an XY moving table drive mechanism which does not require backlash, is small, and does not require a large space.

[0006]

[Means for Solving the Problems]

 An XY moving table driving mechanism according to the present invention includes a Y moving table that moves in the Y direction, an X moving table movably mounted on the Y moving table in the X direction orthogonal to the Y direction, and a Y moving table. Arranged in a direction orthogonal to the feed screw for driving the X-moving table that moves as a unit in the X direction, the ball screw for moving the X-moving table in the X direction by the rotation of the feed screw, and the feed screw. The rotating shaft joined to the rotating shaft and the rotating member move independently in the Y direction with the movement of the Y moving table, but rotate by the rotation of the rotating shaft, and the rotating member and the X motion feed. It is characterized by comprising a screw gear provided on each of the screws and for transmitting the rotation of the rotating member to the X-motion feed screw.

[0007]

[Action]

 The XY moving table drive mechanism according to the present invention rotates the rotating shaft when moving the X moving table, and the rotation of the rotating shaft moves in the Y direction independently of the rotating shaft as the Y moving table moves. The rotating member is rotated, and the rotation of the rotating member is transmitted to the X-motion feed screw by the screw gear to move the X-motion table.

[0008]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of an XY moving table drive mechanism according to the present invention, and FIG. 3 shows details of a screw gear portion used in the embodiment of FIG. The same parts as those of the embodiment of FIG. 1 and the conventional mechanism of FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted. The difference between this embodiment and the conventional example of FIG. 1 is the moving mechanism of the X-moving table 6. A screw gear (spiral gear) 20 is provided at the tip of the feed screw 8 meshing with the ball screw 7 for driving the X motion table, instead of the bevel gear. The screw gear 20 is meshed with a screw gear 22 that rotates together with a rotary shaft 21 for X movement. The screw gear 22 is connected to the shaft 21 by a ball spline mechanism 24 so that the screw gear 22 can move straight along the rotary shaft 21 integrally with the housing 23. The housing 23 is fixed to the Y moving table 3.

With such a structure, when the X-moving table 6 is moved, when the rotary shaft 21 is rotated, the rotation of the rotary shaft 21 is transmitted to the screw gear 22 via the ball spline mechanism 24, and the screw gear 22 is rotated. The rotation of the gear 22 is transmitted to the screw gear 20. By the rotation of the screw gear 20, the feed screw 8 rotates, the ball screw 7 moves linearly on the feed screw 8, and the X-moving table 6 moves vertically in the drawing. When the Y-movable table 3 is moved in the left-right direction in the figure by driving from the same direction as the rotary shaft 21, the housing 23 moves in the left-right direction together with the Y-movable table 3. Therefore, the meshing between the screw gear 22 inside the housing 23 and the screw gear 20 at the tip of the feed screw does not disengage even when the Y moving table 3 moves.

As described above, in the above-described embodiment, the heights of the X-movement feed screw 8 and the X-movement drive mechanism such as the ball spline mechanism 24 and the rotary shaft 21 are different, and the movements of the X-movement table 6 and the drive mechanism are different. Since they do not interfere with each other, there is an advantage that the entire device can be downsized and a large amount of movement in the X direction can be obtained. Further, since the ball spline mechanism is used as a mechanism for following the movement of the Y movement table 3, backlash does not occur in this portion, and the movement accuracy of the X movement can be improved. Further, since the screw gear and the ball spline mechanism are integrated, there is no need to move the rotary shaft by moving the Y-moving table, and this also allows the mechanism to be downsized.

[0011]

[Effect of the device]

 As described above, the XY moving table driving mechanism according to the present invention rotates the rotating shaft when moving the X moving table, and the rotation of the rotating shaft causes the rotating shaft to move as the Y moving table moves. Independently from, the rotating member that moves in the Y direction is rotated, and the rotation of this rotating member is transmitted to the X motion feed screw by the screw gear to move the X motion table, so there is no backlash and it is small and large. A mechanism that does not require space can be realized.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an XY drive mechanism according to the present invention.

FIG. 2 is a diagram showing a conventional XY moving table drive mechanism.

FIG. 3 is a diagram showing details of a screw gear portion used in the embodiment of FIG.

[Explanation of symbols]

 1, 2 ... Y motion rail 3 ... Y motion table 4, 5 ... X motion rail 6 ... X motion table 7 ... Ball screw 8 ... Feed screw 20,22 ... Screw gear 21 ... Rotary shaft 23 ... Housing 24 ... Ball spline mechanism

Claims (1)

[Scope of utility model registration request] 1. A Y moving table which moves in the Y direction, an X moving table which is movably mounted on the Y moving table in an X direction orthogonal to the Y direction, and an X which moves integrally with the Y moving table. A feed screw for driving the moving table in the X direction, a ball screw for moving the X moving table in the X direction by rotation of the feed screw, a rotary shaft arranged in a direction orthogonal to the feed screw, A rotary member that is joined to the shaft and that moves in the Y direction independently of the rotary shaft with the movement of the Y motion table, but that rotates by the rotation of the rotary shaft, and that is provided on each of the rotary member and the X motion feed screw. An XY moving table drive mechanism composed of a screw gear for transmitting the rotation of the member to the X movement feed screw.