JPS62107312A - Positioning table - Google Patents

Abstract

PURPOSE:To raise the accuracy of a driving means, and to improve the positioning accuracy of a table by driving a roller of the upper table through a wedge block. CONSTITUTION:The titled table is constituted of the upper table 13 having a plane, pole groups 14a-14c for controlling this upper table so that it moves in one plane, three pieces of rollers 19a-19c which have been provided on the upper table, three pieces of wedge blocks 22a-22c having an abutting surface for abutting on these rollers, and driving means 23a-23c for driving this wedge block in the direction having a prescribed angle against the surface for abutting on the roller. The accuracy and the rigidity of the driving means are raised by the wedge block, and a positioning table whose accuracy and rigidity are high can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is carried out, for example, to align a wafer with a pattern mask in an exposure step of a semiconductor manufacturing process. This relates to a positioning table used for positioning wafers, etc.

In conventional positioning tables, the X=Y axis perpendicular to the mutual IZ-1 and the rotational θ axis are generally used by stacking two linear tables and one rotary table, but in this method, Since the three-tier structure increases the height dimension of the device, it is difficult to design it compactly.
This has the disadvantage that the rigidity in the vertical direction is also low.

In order to improve this problem, a one-stage table as shown in Japanese Patent Laid-Open No. 59-72727 has been proposed. Second
The figure shows a conventional positioning cheagle disclosed in Japanese Unexamined Patent Publication No. 59-72727.

In FIG. 2, 1 is a base plate and 2 is an upper table on which the position is positioned. There is a group of balls 3 arranged on the circumference between the base plate 1 and the upper table 2, and together with the weight of the upper table 2, the upper table 2 is regulated on one plane on the base 1. .

The upper table 2 is provided with rollers 4a, 4b, and 4c. Motors 5a and 5b on the base 1.

6C is installed, and these motors sa and sb.

Blockers a, 7b, 7C are connected to guides 8a, 8b, 8 by screws 6a, 6b, 6c driven by screws 6C.
Move along c. The springs 9a, 9b, 9c act on the upper table 2 in the axial direction of the screws 6a, 6b, 6c, and the rollers 4a, 4b, 4ci push 7a.

Press 7b and 7c.

With the configuration described below, when the motors 5a, 5b, and 5c are driven one time, the upper table 2 moves in the XY.theta. direction.

. However, this conventional example has the following drawbacks. First, the rollers 4a, 4b, and 4c are screwed sa and eb.

Because it moves in the axial direction of screw 6C, the accuracy of screws 6a, 6b, and 6c directly appears as the positioning accuracy of the table, and screw 6a
, esb, 6c, the positioning accuracy of the upper table 2 cannot be improved beyond the processing accuracy of .

Further, the force acting on the upper table 2 is directly applied to the screw 6a.

Since it acts in the axial direction of eb and 6c, especially when a high-precision ball screw is used for the screw, the stiffness of the Nand appears as the stiffness of the table, so the stiffness of the table in the position regulation direction becomes low.

To solve the above-mentioned problems, a stage positioning device of a type in which a trapezoidal cam is driven by a friction wheel as shown in FIG. 6 has been proposed in Japanese Patent Laid-Open No. 178728/1983.

In FIG. 6, 51 is a stage base, 62 is an XY stage, 63 is a trapezoidal cam, 64 is a support wheel, 56 is a rotating support shaft, 6 is a spring, and 67 is a roller.

Problems to be Solved by the Invention However, in the conventional example shown in FIG. 5, two trapezoidal cams with two parallel surfaces are located on one side of the table, so the stroke of each trapezoidal cam is large. The support shaft 54 of each trapezoidal cam (with respect to the predetermined inclination angle formed by the surface that contacts the roller 67
The stroke of the stage table also becomes small, which poses a problem in that it is difficult to improve accuracy.

In view of the above problems, the present invention provides a positioning table with high positioning accuracy and high rigidity in the regulating direction.

Means for Solving the Problems In order to solve the above problems, the positioning table of the present invention includes an upper table having a flat surface, a regulating means for restricting the upper table to move within one plane, and a regulating means provided on the upper table. three wedge blocks that have contact surfaces that come into contact with the rollers, a spring that fully biases the upper table so as to press the rollers against the contact surfaces, and a wedge block that has contact surfaces that contact the rollers. On the other hand, it is fully equipped with drive and auxiliary stages that drive in a direction with a constant 1lji inclination, and among the three contact surfaces, 21'Ai, which are parallel to each other, is placed at a position that sandwiches the -1-table. be.

Function: With the above-described configuration, the present invention drives the rollers of the upper table via the wedge block.1, the accuracy of the driving means is increased by the wedge block, and the positioning accuracy of the table is improved.

EXAMPLE Hereinafter, a positioning table according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a positioning table according to an embodiment of the present invention, FIG. 3 is a partially sectional plan view, and FIG. 4 is a sectional side view.

The positioning dople of this embodiment has a stroke of 2M in both X and Y, and a feed resolution of approximately 0.1 μm.

In Figures 1, 3, and 4, 11 is the base plate %1
2 is a lower table, 13 is an upper table, and the lower table 12 is fixed to the base 11 (C).
is placed on the lower table 12 via three ball groups 14a11ab and 1ac. 3rd group of balls 14
a, 14b.

Balls 14C are kept at appropriate intervals by retainers 15a, i5b, 15C, and 15.

However, the retainers 1 sb and 15c are not shown in the figure. Lower table 12 and third group of balls 14a.

14b and 14C are regulating means for moving the upper table 13 within one plane.

Since this embodiment includes three sets of units of the same shape, parts common to each unit are indicated by subscripts a, b, and c.

There are plaques (17a) in three places on the upper table 13.

Sill rollers 19a, 19b, 19c are attached to 17b, 17c and vias 1sa, 1sb, 1sc. Here, the rollers 19a, 19b, 19c are connected to the pins 18a,
It is rotatably attached around the axes 18b and 18c.

On the other hand, the base plate 11 is provided with a guide block 20a.

20b + 20c are fixed, and this guide block 2
Slide guides 21a are provided at 0a, 20b, and 20c.

21b, 2IC via Kuzabip 0. ri22
a.

22b and 22c are slidably attached.

Ball screws 24a, 24b, 24c and a pulse motor 26d constitute means 23a, 2ab, 23c for driving the wedge rollers 22a, 22b, 22c.

25b, 25c are Funecta 26a, 26b, 2
The shafts are fixed together with 6c. Ball screw 24a.

24b and 24c are bearings 27a and 2ab.

27c (27b and 27c are omitted from the diagram) and Plaqueno) 2
Guide block 20a via 8a, 28b, 28c
, 20b, 20c, and the pulse motor 25
a, 26b, and 26c are also brackets 29a.

Guide block 20a via 29b and 29c.

It is attached to 20b and 20G. Furthermore, ball screw nuts 30a, 30b, and 30c are fixed to wedge blocks 22a, 22b, and 22c, respectively.

With this configuration, pulse motors 25a and 25b.

When 25c is moved @, wedge blocks 22a, 22
b.

22c moves in the axial direction of the ball screws 24a, 24b, 24c. In addition, Kusabibu 0:, Ri22a.

22b, 22c are contact surfaces 31a, 31b, 31c which are flat surfaces that contact the rollers 19a, 19b, 19c.
have. These contact surfaces 31a, 31b, 3
1C is inclined at a constant angle α with respect to the rotation axis of the ball screws 24a, 24b, and 24c.

On the other hand, the upper table 13 has brackets 32, 33°34
．． 36 and spring bracket pins 3613 and 38.39 are provided, and spring bracket pins 40° and 41.42 are provided on the base plate 11.
．． 43 is fixed. A tension spring 44 is placed between spring holder pins 36 and 40, a tension spring 46 is placed between spring holder pins 37 and 41, a tension spring 46 is placed between spring holder pins 38 and 42, and a tension spring 46 is placed between spring holder pins 39 and 43. are each tensioned by a tension spring 47, roller 19a is tensioned by tension spring 4F>, 47 to contact surface 31a of wedge block 22a, and roller 19b is tensioned to contact surface 31b of wedge block 22b by tension spring 44, roller 19C. is the contact surface 31 of the wedge block 22c by the tension spring 46.
C is pressed respectively.

As shown in FIG. 3, the wedge pin sockets 22a, 22b, and 22c are arranged in contact with the contact surface 31a of the wedge block 22a and the other wedge block 22b.

The abutting surfaces 31b and 31c of the wedge block 22c are perpendicular to each other, and the abutting surfaces 31b and 31c of the wedge block 22b and 22c are parallel to each other and are positioned to sandwich the upper table 13. When frozen, rollers 19b, 19
The position of c is such that there is a distance L (L>o) between a perpendicular line passing through the center of the roller 19b and dropping down to the contact surface 31b and a perpendicular line E passing through the center of the roller 19C and dropping down to the contact surface 31Cp. I decide.

Now, the direction parallel to the abutting surface 31a is 'ffzx, the perpendicular direction is y, and the angle α between the abutting surface 31& and the rotation axis of the ball screw 24a is, for example, (1=sin -" (1/2o), The lead of the ball screw 24a is 2 mm.

Here, the pulse motor 25a is driven and the T-pole screw 24a is
f When turned by 171,000 revolutions, wedge block 2
2& moves 2 μm, and the roller 19ald moves o, i in the Y direction.
4. The rollers 19b and 190 that move by μm are also similar to 19a,
The principle of positioning the upper table 1'1 in the x, y, and θ directions by positioning the rollers 19a, 19b, and 19C is well-known as disclosed in Japanese Patent Laid-Open No. 69-72727. Therefore, it is omitted here.

As described above, in this embodiment, the pulse motor 26a.

25b and 25c, the upper table 13
positioning in the force direction is possible. At this time, the lead error δ of the ball screws 24a, 24b, 24C that drive the wedge blocks 22a, 22b, 22c is:
Kusabipu: 7J contact surfaces 31a, 31b, 31c of 22a, 22b, 22c and ball screws 24a, 24b
, 24a, the rollers 19a, 1
The positioning error ε of 9b and 19c appears small as ε:=δ~5ina. Therefore, the highest P of upper table 13
Positioning will be 8 degrees or higher.

Place the cut rollers 19a, 19b, and 19c into wedge block
Pulse motor 25 via 2a, 22b, 22c
a, 26b, 26c and the ball screw 24a.

Since it is driven by 24b and 24C, the upper table 1
The external force acting on the wedge block 22a is the external force acting on the wedge block 22a.

22b, 22c, and a ball screw 24a.

It does not directly join the nuts 30a, 30b, 30c of 24b, 24C. For this reason, the ball screw 24a.

24b, 24G nuts 30a, 30b, 30c
The rigidity of the upper table 13 in the regulating direction can be made larger than the rigidity of the upper table 13.

Further, the contact surfaces 31b and 31c which are parallel to each other are the upper table 1.
Because it is in a position sandwiching 3, the wedge block 22b,
22c can have a large stroke, and has high accuracy and reliability.

! , hole screws 24a, 24b are used as drive means.

24c and pa/l, smoke 25a, 25b, 25c
By using this, the configuration of the device is simple, the handling becomes easy, and a highly accurate positioning table can be realized.

Effects of the Invention As described above, the present invention comprises an upper table having a plane, a regulating means for regulating the upper table to move within a plane, a 31-hard roller provided on the lower table, and A wedge block is still in contact with the roller, and this wedge block is driven in a direction having a certain angle to the roller. The accuracy of the driving means because it consists of the driving means.

The rigidity is increased by the wedge block, providing a positioning table with high precision and rigidity.

In addition, by arranging the wedge block so that the two mutually parallel abutting surfaces are in the position where the upper table metal is sandwiched, the moving stroke of the wedge block can be extended, resulting in a highly accurate and reliable positioning table. can be provided.

In addition, as one drive means for the wedge block, a ball screw and a pulse motor with an axial metal in an oblique direction are used on the contact surface of the wedge block with the center roller, resulting in high accuracy and ease of handling. A positioning table can be provided.

[Brief explanation of drawings]

FIG. 2 is a plan view of a cam-driven stage positioning device. 11...Base ffl, 12...Lower table, 13...Upper table, 14a, 14b,
14. c...Ball group, 16a, 15b, 1
6c, 16----retainer, 19a, 19b, 1
9c...-=-roller, 22a. 22b, 22c=...wedge block, 23a
, 23b. 23 c-= --- driving means, 24a, 24b,
24cm-・Ball screw, 25a, 25b, 26c
m...-pulse motor, 31a, 31b,
31 c...--contact surface, 44.45, 46.4
7...Tension spring. Name of agent: Patent attorney Toshio Nakao and 1 other person11
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゛-Virus (-ta 3feb-3fc ---% #y. 44' da 7---57 green l (gito figure 2 figure 3 figure 4 figure g=, S5 figure

Claims (2)

[Claims] (1) An upper table having a flat surface, a regulating means for regulating the upper table to move within one plane, three rollers rotatably provided on the upper table, and an abutment that abuts the rollers. three wedge blocks each having a contact surface, a spring that biases the roller to press the roller against the contact surface, and driving the wedge block in a direction having a constant inclination with respect to the contact surface. Of the three contact surfaces, one set of two surfaces are parallel to each other and positioned to sandwich the upper table, and another set of two surfaces are perpendicular to each other. A positioning table characterized in that the wedge blocks are arranged so that (2) As a drive means for the wedge block, a ball screw having an axial direction in a direction inclined to the contact surface and a pulse motor for driving the ball screw are used. positioning table.