JP5343728B2 - 2-axis stage device - Google Patents

Description

  The present invention relates to a biaxial stage device that moves a moving object placed on a table, and more particularly to a biaxial stage device that can be applied to a vacuum vessel.

  In matrix-assisted laser desorption / ionization (MALDI), a plurality of samples are placed on a stage in a vacuum vessel, and each sample is irradiated with laser for ion generation. Further, in the scanning electron microscope (SEM), the surface of the sample is detected by scanning the surface of the sample two-dimensionally with an electron beam to detect secondary electrons, reflected electrons, and the like emitted from each position of the sample. We are analyzing. In these analyzers, a stage device that moves a sample with each stage is usually used. Thereby, a sample can be appropriately moved to a laser or electron beam irradiation position.

  FIG. 1 shows a configuration of a general two-axis stage apparatus. This two-axis stage device places a sample and moves the X table 9 that can move in the X-axis direction, and the Y table that can place the X table 9 and move in the Y-axis direction orthogonal to the X-axis direction. An X table drive mechanism including an X motor 7, an X joint 8, and an X feed screw 10 connected to the table 4, the X table 9; a Y motor 2, a Y joint 3, connected to the Y table 4; And a Y table drive mechanism composed of a Y feed screw 5. The X feed screw 10 and the Y feed screw 5 are coupled to the shaft of the X motor 7 and the shaft of the Y motor 2 by the X joint 8 and the Y joint 3, respectively. It converts into the linear motion to an axial direction and a Y-axis direction, and moves the X table 9 and the Y table 4 to each axial direction.

  When the stage apparatus is used in a vacuum vessel, it is desirable to provide a drive source such as a motor outside the vacuum vessel. This is because heat is not easily dissipated in a vacuum, and heat generated by operating the drive source easily raises the temperature of the drive source itself. In addition, gas (outgas) is generated from the inside of the drive source that has become high temperature, thereby lowering the degree of vacuum in the vacuum vessel, and the generated outgas is incorporated into the analysis data, thereby adversely affecting the original data of the sample. Sometimes. Therefore, when the drive source is provided in the vacuum vessel, measures such as avoiding long-term continuous operation or reducing the drive speed are required to suppress the temperature rise of the drive source.

  However, in the two-axis stage apparatus of FIG. 1, since the X table driving mechanism moves in the Y axis direction together with the X table as the Y table 4 moves, both the X motor 7 and the Y motor 2 are placed outside the vacuum vessel. It is difficult to place.

  On the other hand, Patent Document 1 describes a two-axis stage device that can be applied to a vacuum vessel. The structure of this two-axis stage device is shown in FIG. 2 includes a base 1, three tables, an X table 9, a Y table 4, and a third table 23, an X feed screw 10 connected to each of the third table 23 and the Y table 4, and The Y feed screw 5 is connected to each of the X feed screw 10 and the Y feed screw 5 and has an X motor 7 and a Y motor 2 provided outside the vacuum vessel 30. The X feed screw 10 and the Y feed screw 5 are arranged on the base 1 so as not to cross each other. Further, the third table 23 and the X table 9 are connected through a long hole 24 provided in the Y table 4 via a coupling member (not shown). This connecting member is configured to be slidable in the Y-axis direction by the slide portion 25.

  The operation of the two-axis stage apparatus in FIG. 2 will be described. In this two-axis stage device, the Y feed screw 5 rotates by operating the Y motor 2, and the Y table 4 connected to the Y feed screw 5 moves back and forth on the Y axis. At this time, the X table 9 placed on the Y table 4 also moves together with the Y table 4, and the connecting member connected to the X table 9 also slides on the slide portion 25 in the Y axis direction. On the other hand, the X feed screw 10 is rotated by operating the X motor 7, and the third table 23 connected to the X feed screw 10 and the X table 9 connected to the third table 23 by the connecting member are connected to the X axis. Move up and down.

  Unlike the conventional two-axis stage apparatus as shown in FIG. 1, the two-axis stage apparatus of Patent Document 1 moves the X motor 7 that is the drive source of the X table 9 despite the movement of the Y table 4. do not do. Therefore, both the X motor 7 and the Y motor 2 can be arranged outside the vacuum container 30, and the problem caused by the heat generated by the motor can be solved.

JP 2004-317758 A ([0012] to [0016], FIG. 4)

  In the biaxial stage device of Patent Document 1, two feed screws cannot be crossed with each other due to structural problems. Therefore, one of the two feed screws (Y feed screw 5 in FIG. 2) needs to be arranged at the end of the base 1 so that the X table 9 on which the sample is placed can move on the entire surface of the base 1.

  Further, since the rotation axes of the X motor 7 and the Y motor 2 are orthogonal to each other, these motors are respectively disposed outside two orthogonal side surfaces of the vacuum vessel 30. In addition, since it is desirable that the distance between the motor and the feed screw is short for reasons such as power transmission and stage movement accuracy, the two-axis stage device is installed near the corner of the vacuum vessel.

  As described above, the biaxial stage device of Patent Document 1 has a low degree of freedom in design and installation. Since there are many restrictions on the arrangement of various devices such as detectors used for analysis in the analysis apparatus, it is desirable that the design apparatus and the degree of freedom of installation of the stage apparatus be high so as not to disturb the arrangement of these apparatuses. Further, due to the problem of maintainability, it is required that the drive sources (motors) of the respective axes be arranged close to each other.

  An object of the present invention is to provide a two-axis stage device that can be applied to a vacuum vessel, has a high degree of freedom in design and installation, and has good maintainability.

A two-axis stage device according to the present invention, which has been made to solve the above problems,
A first table for placing the object to be moved and movable in the first direction; a second table for placing the first table and movable in a second direction perpendicular to the first direction; In a two-axis stage apparatus comprising a first table moving means and a second table moving means for moving the first table and the second table in a first direction and a second direction, respectively.
The first table moving means is configured to rotate about the second direction as a rotation center; a spline shaft extending in the second direction and connected to a rotation shaft of the first drive source; A spline bearing that is movable along the spline shaft and that transmits the rotational torque of the spline shaft, and the rotational torque transmitted from the spline bearing is converted into a linear motion of the first table in the first direction. A first rotation-linear conversion mechanism,
The second table moving means converts a second drive source that performs a rotational motion about the second direction as a rotation center, and converts the rotational motion of the second drive source into a linear motion of the second table in the second direction. And a second rotation-linear conversion mechanism.

  With the two-axis stage device according to the present invention, the movement of the first table is performed by the first rotation-linear conversion mechanism. The spline shaft only transmits its rotational motion to the first rotation-linear conversion mechanism via the spline bearing, and the spline shaft does not move with the movement of the second table. Thereby, since the drive source of the 1st table moving means and the drive source of the 2nd table moving means can be fixed together, it becomes possible to apply the biaxial stage device of the present invention to a vacuum vessel.

  The biaxial stage device of the present invention has a structure in which the direction of the rotation axis of the first drive source and the direction of the rotation axis of the second drive source coincide. Thereby, since the freedom degree of arrangement | positioning of these 2 axes | shafts increases, the design freedom degree of a stage apparatus can be made high. In addition, since the directions of the rotating shafts coincide with each other, the first drive source and the second drive source can be integrated on the same plane. Therefore, when applied to a vacuum vessel, the stage device is not a corner of the vacuum vessel. Can also be arranged. Further, by concentrating the drive sources on the same surface, it is possible to reduce the size of the apparatus incorporating the two-axis stage apparatus of the present invention, and to obtain an effect that the maintainability is improved.

A top view (a) and a side view (b) of a conventional two-axis stage device in which a motor of one axis moves. The top view of the conventional 2 axis | shaft stage apparatus with which the motor of both axes was fixed together. The top view (a), AA 'sectional view (b), side view (c), and BB' sectional view (d) which show the 1st example of the 2 axis stage device concerning the present invention. The top view (a) which shows the 1st modification of the biaxial stage apparatus of 1st Example, AA 'sectional drawing (b), and a side view (c). The top view (a) which shows the 2nd modification of the biaxial stage apparatus of 1st Example, AA 'sectional drawing (b), a side view (c), and a perspective view (d). The top view which shows a steel belt. The top view (a), the side view (b), and BB 'sectional view (c) which show 2nd Example of the biaxial stage apparatus based on this invention. Schematic which shows the connection of the motor periphery of the biaxial stage apparatus in the modification of 2nd Example.

A first embodiment of a two-axis stage apparatus according to the present invention will be described with reference to FIG. In the following embodiments, the first direction is the X-axis direction and the second direction is the Y-axis direction.
The stage apparatus of this embodiment includes a base 1, an X motor (first drive source) 7 and a Y motor (second drive source) 2 attached to one end of the base 1, and the X motor 7 and Y. A ball spline shaft 101 and a Y feed screw 5 connected to the rotating shaft of the motor 2 via an X joint 8 and a Y joint 3, and a spline bearing 14 movable in the Y axis direction along the ball spline shaft 101; A gear 13 fixed to the spline bearing 14; a Y table (second table) 4 mounted on the base 1 and movable in the Y-axis direction along a Y-direction guide 6 provided on the base 1; An intermediate table 15 fixed to the spline bearing 14 and movable in the Y-axis direction along the ball spline shaft 101, and placed on the Y table 4 via the intermediate table 15; And X-direction guide 11 movable in the X-axis direction along the X-table (first table) 9 provided on the table 15, and a, a rack 12 fixed to the lower surface of the X table 9.

  The gear 13, the rack 12, and the intermediate table 15 transmit the rotational motion of the ball spline shaft 101 and the spline bearing 14 that rotate about the Y-axis direction to the X table 9 on the intermediate table 15 via the gear 13 and the rack 12. Is a first rotation-linear motion conversion mechanism that converts the X table 9 into a linear motion in the X-axis direction. The Y feed screw 5 is a second rotation-linear motion conversion mechanism that converts the rotational motion of the Y motor 2 centering on the Y-axis direction into the linear motion of the Y table 4 in the Y-axis direction.

  The spline bearing 14 is a mechanical element that can transmit torque generated by the rotation of the ball spline shaft 101 to another while performing linear motion along the ball spline shaft 101. FIG. 3D shows a longitudinal sectional view around the spline bearing 14. The spline bearing 14 includes a spline nut 141, a support bearing 142, and a flange 143, and these have an integrated structure. The spline nut 141 can move in the Y-axis direction along the ball spline shaft 101 and can rotate around the Y-axis direction as the ball spline shaft rotates. On the other hand, the flange 143 is fixed to the intermediate table 15. Since the support bearing 142 is incorporated between the flange 143 and the spline nut 141, the flange 143 does not rotate even if the spline nut 141 rotates.

  As described above, since the flange 143 of the spline bearing 14 is fixed to the intermediate table 15, the intermediate table 15 placed on the Y table 4 and the intermediate table 15 are moved along with the movement of the Y table 4. The fixed spline bearing 14 moves along the ball spline shaft 101 in the Y-axis direction. On the other hand, since the gear 13 is fixed to the spline nut 141 and the rack 12 that receives the rotation of the gear 13 is fixed to the X table 9, the rotation of the ball spline shaft 101 causes the X table 9 to move to the intermediate table 15. It moves in the X axis direction along the X direction guide 11. With the above configuration, the X table 9 can be moved in the X-axis direction while fixing the positions of the ball spline shaft 101 and the X motor 7 regardless of the position of the Y table 4 on the Y-axis.

  FIG. 4 shows a first modification of the two-axis stage device of the present embodiment. In the biaxial stage apparatus of FIG. 3, the rotational motion of the ball spline shaft 101 and the spline bearing 14 is converted into linear motion in the X-axis direction by a rack-pinion. In this modification, a timing belt or a steel belt is used. It is converted to linear motion in the X axis direction. The large pulley 17 is fixed to the spline nut 141, and the small pulley 18 can freely rotate about the rotating shaft 19 fixed to the intermediate table 15. Accordingly, the large pulley 17 rotates by the rotation of the ball spline shaft 101, and the X table 9 coupled to the timing belt 20 moves in the X axis direction.

  FIG. 5 shows a second modification of the biaxial stage device of the present embodiment. In this modification, a steel belt 22 having a shape as shown in FIG. 6 is wound around a pulley 21 fixed to a spline nut 141 and both ends are fixed to an X table 9. Accordingly, the pulley 21 is rotated by the rotation of the ball spline shaft 101, and the rotational torque is transmitted by the steel belt 22 wound with α, so that the X table 9 moves in the X axis direction.

A second embodiment of the two-axis stage apparatus according to the present invention will be described with reference to FIG.
In this embodiment, the biaxial stage device of the first embodiment is applied to a vacuum vessel. The biaxial stage device of the first embodiment is installed on a vacuum vessel base 301 that is a base portion of the vacuum vessel 30. The vacuum vessel 30 can maintain a vacuum state by attaching a vacuum vessel cover (not shown) to the vacuum vessel base 301 and exhausting the inside.
The biaxial stage apparatus of the present embodiment has a structure in which the X motor 7 and the Y motor 2 are arranged outside the vacuum vessel 30. Since the vacuum vessel 30 (vacuum vessel base 301) is provided with a motor shaft insertion port, a seal member is provided at the motor shaft insertion port so that the internal airtightness can be maintained. In this embodiment, an O-ring 31 is used as a seal member, an O-ring groove is formed in the motor shaft insertion opening, and the O-ring 31 is fitted in the O-ring groove.

  In the two-axis stage device according to the present invention, since the rotation axes of the X motor 7 and the Y motor 2 are both in the same direction, these motors can be integrated on one surface of the vacuum vessel 30. Thereby, a biaxial stage apparatus can be installed in addition to the corner of the vacuum container 30, and the freedom degree of installation can be improved. In addition, there is an effect that maintenance of the X motor 7 and the Y motor 2 becomes easy.

  When an O-ring is used as a sealing member as described above, for example, when the motor is removed from the vacuum vessel such as replacing the motor, it is necessary to remove the vacuum vessel cover in order to remove the coupling between the motor and the joint. Will be torn. Further, since an O-ring is used on the sliding surface, it is necessary to periodically replace the O-ring. FIG. 8 shows a modification that solves this problem. In this modification, a magnetic seal 16 is incorporated between the Y feed screw 5 and the shaft of the Y motor 2 and between the ball spline shaft 101 and the shaft of the X motor 7, and further, the X motor 7 and the Y motor 2 and the magnetic seal 16 are assembled. The X joint 8 and the Y joint 3 are provided therebetween. The magnetic seal 16 used in this modification has a structure in which the periphery of the rotating shaft is fixed with a magnetic fluid, and the airtightness around the rotating shaft is maintained even when the rotating shaft rotates. In addition, the airtightness between the housing of the magnetic seal 16 and the opening provided in the side wall of the vacuum vessel is maintained by an O-ring (not shown) provided therebetween. Thereby, even if the X motor 7 and the Y motor 2 are removed at the joint portion in the atmosphere, the airtightness inside the vacuum container can be maintained, and the replacement work of each motor can be performed without breaking the vacuum. Further, periodic replacement of the O-ring used for the motor shaft becomes unnecessary.

  In the second embodiment and its modification, an example in which the biaxial stage device according to the present invention is applied to a vacuum container has been shown. However, a container other than a vacuum container, such as a sealed container filled with an inert gas. Needless to say, this is also applicable to the above.

DESCRIPTION OF SYMBOLS 1 ... Base 2 ... Y motor 3 ... Y joint 4 ... Y table 5 ... Y feed screw 6 ... Y direction guide 7 ... X motor 8 ... X joint 9 ... X table 10 ... X feed screw 101 ... Ball spline shaft 11 ... X Direction guide 12 ... Rack 13 ... Gear 14 ... Spline bearing 141 ... Spline nut 142 ... Support bearing 143 ... Flange 15 ... Intermediate table 16 ... Magnetic seal 17 ... Large pulley 18 ... Small pulley 19 ... Rotating shaft 20 ... Timing belt 21 ... Pulley 22 ... Steel belt 23 ... Third table 24 ... Punch hole 25 ... Slide part 30 ... Vacuum vessel 301 ... Vacuum vessel base 31 ... O-ring

Claims (7)

A first table for placing the object to be moved and movable in the first direction; a second table for placing the first table and movable in a second direction perpendicular to the first direction; In a two-axis stage apparatus comprising a first table moving means and a second table moving means for moving the first table and the second table in a first direction and a second direction, respectively.
The first table moving means is configured to rotate about the second direction as a rotation center; a spline shaft extending in the second direction and connected to a rotation shaft of the first drive source; A spline bearing that is movable along the spline shaft and that transmits the rotational torque of the spline shaft, and the rotational torque transmitted from the spline bearing is converted into a linear motion of the first table in the first direction. A first rotation-linear conversion mechanism,
The second table moving means converts a second drive source that performs a rotational motion about the second direction as a rotation center, and converts the rotational motion of the second drive source into a linear motion of the second table in the second direction. And a second rotation-linear conversion mechanism.   The first rotation-linear conversion mechanism is mounted on the second table, an intermediate table for mounting the first table, a gear fixed to the spline bearing, and a rack fixed to the first table The two-axis stage device according to claim 1, comprising:   The first rotation-linear conversion mechanism is mounted on the second table, an intermediate table for mounting the first table, a first pulley fixed to the spline bearing, and fixed to the intermediate table, 2. The biaxial stage device according to claim 1, comprising: a second pulley having the second direction as a rotation axis; and a belt stretched between the second pulleys of the first pulley.   The first rotation-linear conversion mechanism is placed on the second table, an intermediate table for placing the first table, a pulley fixed to the spline bearing, and α wound around the pulley. 2. The biaxial stage device according to claim 1, comprising: a belt fixed to the intermediate table.   5. The biaxial stage device according to claim 1, wherein the first drive source and the second drive source are installed outside a vacuum vessel via a seal member.   The biaxial stage device according to claim 5, wherein the seal member is a magnetic seal.   The biaxial stage apparatus according to claim 6, wherein a joint is provided between the first drive source and the second drive source and the magnetic seal.

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