JP2661092B2 - Travel guide device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a moving guide device, and more particularly, to a semiconductor manufacturing device, a precision machine tool, or the like, in which a linear motor is used as a driving means by a moving body such as an X stage or a Y stage. The present invention relates to a movement guide device that can be used to position a predetermined position at high speed and with high accuracy.

(Prior Art) Conventionally, various types of moving guide devices have been proposed in which a moving body is moved along a predetermined guide by a driving means such as a linear motor to perform positioning at a predetermined position with high accuracy.

FIG. 4 is a perspective view of a main part of a multipolar linear motor used as a driving means in a conventional moving guide device.

In the linear motor shown in the figure, a permanent magnet (field magnet) 41A and a yoke 42A are opposed to one side surface, and permanent magnets 41B, 41C and yokes 42B, 42C are opposed to each other via a nonmagnetic spacer 43. Have been placed. The coil 45 wound around the coil bobbin 44 moves through the space therebetween.

The position and speed of the coil 45 are limited by the current and frequency supplied to the coil 45.

In general, the moving guide device is configured such that the moving body is fixed to the coil bobbin 44 and the yoke 42A is directly fixed to the base plate serving as a base. When an electric current is applied to the coil 45, Joule heat is generated, and the coil bobbin 44, the permanent magnets 41A, 41B, 41
C and the temperatures of the yokes 42A, 42B, 42C, etc. rise.

For this reason, the temperature of the moving body and the surface plate fastened to the coil bobbin 44 and the yokes 42A, 42B, 42C and the like increases.

When the temperature of the moving body and the surface plate rises, their shapes are bent and deformed, and as a result, the moving accuracy of the moving body decreases. For example, if a temperature difference of 0.5 ° C occurs between the front and back of a 40 mm thick platen, a moving
A milliradian tilt error occurs. JP 62-4538
Japanese Patent Application Laid-Open Publication No. H11-15083 proposes a movement guide device that prevents a decrease in the movement accuracy of a moving body due to heat generated by a linear motor, but the heat transfer path portion is not always sufficient.

(Problems to be Solved by the Invention) In the present invention, when a moving body is moved by using a linear motor as a driving means, heat generated from the linear motor is effectively insulated and heat is transferred to the moving body and the surface plate. Not to
An object of the present invention is to provide a movement guide device that enables highly accurate movement.

(Means for Solving the Problems) A surface plate having a reference surface, a guide provided on the surface plate, a first moving body guided in the guide and moved in a first direction,
A first linear motor driving the first moving body;
A second direction guided by a moving body and orthogonal to the first direction;
Moving body, a second linear motor provided between the first moving body and the second moving body for driving the second moving body, and the first moving body with respect to the reference plane. A first hydrostatic bearing for supporting the gas with a gas;
A second hydrostatic bearing for supporting the moving body with a gas, wherein at least one of the first and second linear motors is connected to the first moving body via a heat insulating material and a spacer made of a material harder than the heat insulating material. Or, it is connected to the second mobile unit.

(Embodiment) FIG. 1 is a perspective view of an essential part of an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA 'of FIG. In the figure, reference numeral 15 denotes a surface plate, the upper surface of which is a smooth reference surface. 10 is surface plate 15
A Y stage as a first moving body that moves in the Y-axis direction above, 11 is an X stage as a second moving body that moves in the X-axis direction using the Y stage 10 as a guide, and 16a and 16b are on the surface plate 15, respectively. Fixed guides 12a, 12b, 13a, 13b, 13c, and 14 for being fixed and guiding the Y stage 10 in the Y-axis direction.
Reference numerals a and 14b denote porous static pressure air bearings (air bearings). Among them, 14a and 14b regulate the position of the X stage 11 in the Y-axis direction with respect to the Y stage 10, and 13a, 13b and 13c.
Regulates the vertical position of the X stage 11 with respect to the surface plate 15, and 12a and 12b act to regulate the vertical position of the Y stage 10 with respect to the surface plate 15, respectively. The position of the Y stage 10 in the x-axis direction is determined by the Y stage 10 and the fixed guide 16.
The pressure is regulated by a static pressure air bearing (not shown) provided between the a and 16b.

100 is a part of a linear motor (first linear motor) for the Y stage 10, and 200 is a part of a linear motor (second linear motor) for the X stage 11, all of which are moving coil type linear motors.

The stator 2a of the linear motor for the Y stage 10 is fixed to the surface plate 15 by a plastic spacer 8 such as polycarbonate having a smaller thermal conductivity than iron or the like. The gap formed between the stator 2a and the platen 15 by the spacer 8 is filled with a heat insulating material 9 made of an organic material such as styrene foam over the front surface thereof.

The stator 2b of the linear motor for the X stage 11 is fixed inside the concave portion of the Y stage 10 by similar plastic spacers 8a and 8b. A gap formed between the stator 2b and the inner wall of the concave portion of the Y stage 10 is filled with a heat insulating material 9a, 9b, 9c such as styrene foam over the entire surface.

The mover (coil bobbin) 4a of the linear motor for the Y stage 10 is connected to the Y stage 10 by a similar spacer 6 made of a plastic material such as polycarbonate.
A gap formed between the mover 4a and the Y stage 10 by the spacer 6 is filled with a heat insulating material 7 such as styrene foam. Similarly, the mover 4b of the linear motor for the X stage 11 is connected to the X stage 11 by plastic spacers 6a and 6b. On the spacer mounting surface of the X stage 11, a styrofoam insulating material 7a, 7b, 7c is provided over the entire area opposed to the Y stage 10 with the mover 4b and the X stage.
It is provided so as to be located between 11. Note that reference numeral 5 in FIG. 2 is a coil.

In this embodiment, as shown in FIG.
10 is lifted from the surface plate 15 by supplying air to the hydrostatic air bearing 12, and is fixed by two linear motors 100.
It is moved in the Y direction along a and 16b.

The X stage 11 is supplied to the static pressure air bearings 13 and 14 so that the X stage 11 floats from the surface plate 15 similarly to the Y stage 10,
The stage 10 is moved in the X direction by the linear motor 200 using the side surface of the stage 10 as a guide. At this time, the X stage 11 and the Y stage 10 are adjusted by a plurality of preload magnet units (not shown) so as to always have a constant posture. When the X stage 11 and the Y stage 10 are moved, Joule heat is generated by the current flowing through the coil (for example, the coil 5) of the linear motor, and the heat raises the temperature of the movers 4a, 4b and the stators 2a, 2b. I do.

In this embodiment, at this time, the heat insulating materials 7 and 9 prevent heat from being transmitted to the adjacent X stage and Y stage and the surface plate, thereby effectively preventing the temperature of these members from rising.

Further, in this embodiment, the linear motor is firmly connected to the X stage and the Y stage by a relatively hard spacer to prevent improper vibration generated when the linear motor is weakly coupled. The Y stage is moved with high precision.

In addition, in the present embodiment, both the X stage and the Y stage are guided in the vertical direction from the surface plate, so that even if the X stage or the Y stage moves, no moving load is generated on the counterpart stage, and the static stage is performed. Maintain a good attitude.

FIG. 3 is a schematic view of a main part of another embodiment of the present invention when a movable magnet type linear motor is used. 2, the same elements as those shown in FIG. 2 are denoted by the same reference numerals.

In this embodiment, the Y stage 10 as the first moving body
Are supported by static pressure air bearings 12a and 12b.
Further, the vertical direction of the X stage 11 as the second moving body is supported by the static pressure air bearings 13a, 13b, and the horizontal direction is the static pressure air bearings 14a, 1b.
4b supports. 18a and 18b are two sets of permanent magnets, 17a and 17b
Are two sets of yokes which are opposed to each other with spacers 21a and 21b interposed therebetween, and between which the coils 20a and 20b and the coil bobbin 19 on the stator side are arranged.

One of the yokes 17a and 17b, the permanent magnets 18a and 18b, and the spacers 21a and 21b, which are movers, is a spacer 6a and 6b.
Is connected to the X stage 11 through the
It moves linearly with. On the other hand, the coils 20a and 20b on the stator side
The coil bobbin 19 is fixed to the Y stage 10.

The heat insulators 7a, 7b, 7c are filled between the yoke 17a, which is a mover, and the X stage 11, and the heat insulator 9a is arranged on the Y stage 10 so as to surround the movable range of the mover.

As the X stage 11 moves, Joule heat is generated by the current flowing through the coils 20a and 20b, and the temperatures of the mover such as the yoke 17a and the stator such as the coil bobbin 19 rise.

Therefore, in this embodiment, heat transfer to the X stage 11 is prevented by the heat insulating materials 7a, 7b, 7c, and the Y stage 10
To prevent heat transfer. This prevents the temperatures of the X stage, the Y stage, and the surface plate from rising, and prevents the X stage and the Y stage from being deteriorated in moving accuracy due to thermal deformation.

(Effects of the Invention) According to the present invention, by surrounding the coil of the linear motor with a heat insulating material as described above, heat generated from the coil is effectively transferred to the X stage, the Y stage, and the surface plate. Thus, it is possible to achieve a movement guide device that can perform high-precision movement while preventing deterioration in stage movement accuracy due to thermal deformation.

In addition, since the thrust of the linear motor is conducted by using a hard spacer made of plastic such as polycarbonate, and thereby sufficient mechanical strength can be obtained, the insulative effect of styrene foam as a heat insulating material is high, but it is soft. A heat insulator having the following can also be used.

[Brief description of the drawings]

FIG. 1 is a perspective view of an essential part of an embodiment of the present invention, and FIG.
FIG. 3 is a schematic view of another embodiment of the present invention, and FIG. 4 is a perspective view of a main part of a conventional multi-pole linear motor. In the figure, 15 is a surface plate, 10 is a Y stage, 11 is an X stage, 16
a, 16b are fixed guides, 12, 13, 14 are hydrostatic air bearings, 100, 200
Is a linear motor, 2a, 2b are stators, 6, 8, 21 are spacers, 7, 9 are heat insulators, 4a, 4b are movers, 5, 20 are coils, 17 is a yoke, and 19 is a coil bobbin.

Claims (3)

(57) [Claims] A surface plate having a reference surface; a guide provided on the surface plate; a first moving body guided by the guide and moving in a first direction; A first linear motor having a stator fixed to the surface plate and a mover fixed to the first moving body for driving along the guide, and guided by the first moving body. A second moving body that moves in a second direction orthogonal to the first direction, and fixed to the first moving body for driving the second moving body with respect to the first moving body on the reference plane. Stator and the second
A second linear motor having a mover fixed to a moving body; a first hydrostatic bearing for supporting the first moving body with a gas with respect to the reference plane; and a second movement with respect to the reference plane. A second hydrostatic bearing for supporting the body with gas, between the platen and the stator of the first linear motor, between the mover of the first linear motor and the first moving body, At least one of a space between the first moving body and the stator of the second linear motor and a space between the mover of the second linear motor and the second moving body are provided with a heat insulating material and the heat insulating material. A movement guide device wherein a harder material is connected via a spacer. 2. The movement guide device according to claim 1, wherein the heat insulating material is a foamable organic material, and the spacer is a plastic material. 3. The moving guide device according to claim 1, wherein the guide has two guide members provided in parallel.