JP3793871B2 - Stage equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stage apparatus using a linear motor suitable for applications requiring positioning at high speed and high accuracy, such as a transport system for FA equipment.
[0002]
[Prior art]
In general, it is excellent in positioning accuracy and responsiveness in applications such as a transfer system of FA equipment that requires high-speed and high-precision positioning of workpieces and workpieces such as substrates. A linear motor is applied. FIG. 5 shows a general application example in which a conventional linear motor is used for a transport system of an FA device. 5A and 5B show an example in which a conventional linear motor is applied to a stage device, where FIG. 5A is a front view thereof, FIG. 5B is a side view of an X-axis linear motor, and positions of a mover and a stator. It is seen through to show the relationship. In the figure, 10 is a Z-axis linear motor, 11 is a Z-axis actuator, 12 is a slider, 13 is a guide rail, 14 is a moving stage, 15 is a fixed base, 21 is an X-axis linear motor, 22 is a field yoke, and 23 is A permanent magnet, 24 is a yoke base, 25 is an armature, 26 is a coil array, and 27 is a frame. The stage device includes an X-axis linear motor 21 that can reciprocate in the X-axis direction so as to be perpendicular to the paper surface on the fixed base 15, and a Z-axis that can reciprocate in the Z-axis direction on the X-axis linear motor 21. The linear motor 10 and the X-axis linear motor 21 are arranged on the upper part of the moving stage 14 for placing a workpiece or a measurement object, respectively, on the Z-axis linear motor 10 side and the fixed base 15 side. The linear guide is composed of a slider 12 and a guide rail 13 provided. Among these, one X-axis linear motor 21 has a plurality of permanent magnets 23 constituting a field pole arranged in a straight line on the side surfaces of two rows of field yokes 22 so that the N-pole and S-pole polarities are alternately different. The yoke base 24 is disposed between the field yokes 22 to constitute a stator. Further, the X-axis linear motor 21 has a coreless armature 25 arranged opposite to the permanent magnet 23 via a magnetic array and a magnetic gap, and this is used as a mover. The armature 25 has a plurality of coil arrays 26 formed in a flat plate shape, and the coil arrays 26 are arranged in a straight line on both surfaces of a metal or resin core (not shown), and a resin (not shown). It is fixed and integrated with a mold. Further, a stainless steel frame 27 is provided on the upper portion of the armature 25 along the longitudinal direction thereof. For example, a part of a core metal (not shown) of the armature is inserted into the frame 27, The frame 27 is fixed. In the other Z-axis linear motor 10, the Z-axis actuator 11 is configured by, for example, a generally known mechanism including a cylindrical mover and a stator, and the X-axis linear motor 21 moves in the X-axis direction. In this case, it can be moved freely in the Z-axis direction independently. In such a configuration, FIG. 5 shows a position where the Z-axis actuator 11 is moved up and down at a position where the coil array 26 which is the mover of the X-axis linear motor 21 and the permanent magnet 23 which is the stator overlap each other in the height direction. In this case, the X-axis linear motor 21 applies a current to the coil array 26 of each phase from a power source (not shown). An electromagnetic force works from the magnetic field formed in the magnetic gap between the row 26 and the permanent magnet 23 in the longitudinal direction of the coil row 26 to generate a thrust, thereby performing a smooth linear movement.
[0003]
[Problems to be solved by the invention]
However, the prior art has the following problems.
(1) FIG. 6 shows a state when the mover of the conventional X-axis linear motor is moved up and down to the uppermost position with respect to the stator, (a) is a front view thereof, (b). It is the side view. FIGS. 7A and 7B show a state when the mover of the conventional X-axis linear motor is moved up and down to the lowest position with respect to the stator. FIG. 7A is a front view thereof, and FIG. 7B is a side view thereof. It is. In addition, in each figure, S has shown the raising / lowering stroke of the Z-axis linear motor. As shown in FIG. 5, the shape of the coil array 26 and the permanent magnet 23 are equivalent in the height direction. Therefore, when the coil array 26 moves upward in the Z-axis as shown in FIG. It protrudes from the upper part of the permanent magnet 23. Further, when the coil array 26 moves downward in the Z axis as shown in FIG. 7, the coil array 26 protrudes from the lower portion of the permanent magnet 23. For this reason, since the coil current that contributes to the drive that flows through the coil array 26 decreases by the amount that the coil array 26 protrudes from the permanent magnet 23, the X-axis linear motor 21 is moved up and down by the Z-axis actuator 11, for example. When moving up and down in the axial direction and moving in the X-axis direction, which is the horizontal movement direction, the thrust of the X-axis linear motor 21 is reduced.
(2) Also, in (1), when the X-axis linear motor 21 is moved up and down, if the stainless steel frame faces the permanent magnet, a viscous braking force due to eddy current is generated, leading to a loss of thrust of the mover. There was a problem.
(3) Further, the X-axis linear motor 21 has poor cooling performance because no cooling measures are taken for the armature 5 or the frame 7. Therefore, if the temperature rise of the coil array 6 is large, when the heat generated in the coil array 6 is conducted to the moving stage 14 via the frame 7, the moving stage 14 is thermally deformed, and the positioning accuracy of the entire stage apparatus is increased. There was a problem of affecting.
The present invention has been made to solve the above problems, and generates a viscous braking force due to an eddy current when a linear motor that moves in the horizontal direction is applied to a stage device having an up-and-down moving mechanism. It is an object of the present invention to provide a stage apparatus using a linear motor with good cooling performance, which can prevent a decrease in thrust of the mover without doing so.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the present invention of claim 1 is a stator composed of a field yoke in which a plurality of permanent magnets constituting a field pole are arranged in a straight line so that the polarities are alternately different from each other ; the through magnet array and the magnetic air gap of the permanent magnet is constituted by an insulator made of ceramic for supporting armature and said armature having a coil array that facing each towards the longitudinal direction of the magnet array and more composed mover and frame, comprising a, so as to reciprocally move toward the X-axis direction as the horizontal direction with respect to the fixing base, run relative to the armature and the field poles An X-axis linear motor, a moving stage for placing a workpiece or the like provided on the frame of the X-axis linear motor, and both sides of the X-axis linear motor on the fixed base And placed A Z-axis linear motor provided such that the moving stage is movable in the Z-axis direction perpendicular to the fixed base, and a linear guide provided between the Z-axis linear motor and the fixed base; The permanent magnet has a length in a direction orthogonal to a longitudinal direction in which the magnet array is arranged larger than a length in a direction orthogonal to the longitudinal direction of the armature of the coil array. And the frame has a cooling jacket inside, which is a stage apparatus .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a front view showing an example in which the linear motor according to the first embodiment of the present invention is applied to a stage apparatus. In addition, about the same component as this invention, the same code | symbol is attached | subjected and description is abbreviate | omitted, and only a different point is demonstrated.
In the figure, 1 is an X-axis linear motor, 2 is a field yoke, 3 is a permanent magnet, 4 is a yoke base, 5 is an armature, 6 is a coil array, and 7 is a frame.
The present invention is different from the prior art as follows.
The permanent magnet 3 in the X-axis linear motor 1 is that the length in the direction perpendicular to the longitudinal direction in which the magnet row is arranged is larger than the length in the direction perpendicular to the longitudinal direction of the armature 5 of the coil row 6. is there. The frame 7 is made of an insulator, and it is particularly preferable to use ceramic for the insulator.
[0006]
FIG. 2 shows a state when the mover of the X-axis linear motor according to the first embodiment of the present invention moves up and down to the uppermost position with respect to the stator, and (a) is a front view thereof. (B) is a side view thereof. FIG. 3 shows a state when the mover of the X-axis linear motor according to the first embodiment of the present invention moves up and down to the lowest position with respect to the stator, and (a) is a front view thereof. (B) is a side view thereof. In addition, in each figure, S has shown the raising / lowering stroke of the Z-axis linear motor.
In the first embodiment, the permanent magnet 3 of the X-axis linear motor 1 has a length in a direction perpendicular to the longitudinal direction in which the magnet row is arranged, and a direction perpendicular to the longitudinal direction of the armature 5 in the coil row 6. 2, even if the coil array 6 of the mover moves slightly upward in the Z-axis as shown in FIG. 2, the coil array 6 does not protrude from the upper part of the permanent magnet 3. . Further, as shown in FIG. 3, the coil array 6 does not protrude from the lower portion of the permanent magnet 3 even if the coil array 6 moves slightly downward in the Z axis. For this reason, since the coil array 6 does not protrude from the permanent magnet 3, the coil current that contributes to the drive flowing through the coil array 6 does not decrease. When such an X-axis linear motor that moves in the horizontal direction is combined with a stage device having a lifting and lowering mechanism and moved horizontally while moving up and down in the Z-axis direction, the thrust of the X-axis linear motor 1 is not reduced. It can be moved with high accuracy. Further, since the frame 7 is made of an insulator made of ceramic, when the X-axis linear motor 1 is raised and lowered, even if the ceramic frame 7 is applied to the permanent magnet 3, no viscous braking force due to eddy current is generated. The thrust drop of the mover can be prevented.
[0007]
Next, a second embodiment of the present invention will be described.
FIG. 4 is a front view of an X-axis linear motor according to a second embodiment of the present invention.
The second embodiment is different from the first embodiment in that a cooling jacket 8 is provided inside the frame 9 and refrigerant is supplied to the cooling jacket 8 from a refrigerant supply device (not shown). At this time, when a coil current for driving the mover flows through the coil array 6, the coil array 6 generates heat due to the internal resistance, but the heat generated in the coil array 6 is a core metal ( After the heat is transferred to the frame 7 via a not-shown), the heat is exchanged by the refrigerant circulating in the cooling jacket 8. Therefore, the cooling performance of the entire armature 5 can be improved by the cooling jacket 8. Since heat is efficiently exchanged by the frame 7, it is possible to prevent thermal deformation of the moving stage 14, and it is possible to prevent influence on the positioning accuracy of the entire stage device.
[0008]
In this embodiment, the armature of the linear motor is used as a mover and the field pole is used as a stator. However, the armature of the linear motor is used as a stator and the field pole is used as a mover. It doesn't matter. In the present embodiment, the armature coil has been described using an example in which the number of coil arrays is two. However, the structure of the coil arrays may be three, and the combination of the number of coils and the number of phases is limited. It is not something.
[0009]
【The invention's effect】
As described above, the present invention has the following effects.
(1) In the first embodiment, the permanent magnet of the X-axis linear motor has a length in a direction perpendicular to the longitudinal direction in which the magnet row is arranged, in a direction perpendicular to the longitudinal direction of the armature of the coil row. Since it is larger than the length, even if the coil array of the mover moves slightly up and down with respect to the stator, the coil array does not protrude from the upper or lower position of the permanent magnet. It is possible to prevent a decrease in coil current that contributes to driving that flows through the coil. Such an X-axis linear motor that moves in the horizontal direction is combined with a stage device that has a lifting and lowering mechanism, and is moved up and down in the Z-axis direction while moving horizontally, without reducing the thrust of the X-axis linear motor. It can be moved with accuracy. In addition, since the frame is made of an insulator made of ceramic, when the X-axis linear motor is moved up and down, even if the ceramic frame is applied to the permanent magnet, viscous braking force due to eddy current is not generated, and the mover Thrust reduction can be prevented.
(2) In the second embodiment, since the cooling jacket for supplying heat and exchanging heat is provided inside the frame, the heat generated in the coil row is transferred to the frame through the cored bar holding the coil row. The heat exchange is performed by the refrigerant circulating inside the cooling jacket, so that the cooling performance of the entire armature can be improved. Since heat is efficiently exchanged by the frame, it is possible to prevent thermal deformation of the moving stage and to prevent influence on the positioning accuracy of the entire stage apparatus.
[Brief description of the drawings]
FIG. 1 is a front view showing an example in which a linear motor according to a first embodiment of the present invention is applied to a stage apparatus.
FIG. 2 shows a state when the mover of the X-axis linear motor according to the first embodiment of the present invention is moved up and down to the uppermost position with respect to the stator, and (a) is a front view thereof. FIG. 2B is a side view thereof.
FIG. 3 shows a state when the mover of the X-axis linear motor according to the first embodiment of the present invention moves up and down to the lowest position with respect to the stator, and (a) shows the front surface thereof. FIG. 2B is a side view thereof.
FIG. 4 is a front view of an X-axis linear motor according to a second embodiment of the present invention.
5A and 5B show an example in which a conventional linear motor is applied to a stage device, in which FIG. 5A is a front view thereof, and FIG. 5B is a side view of an X-axis linear motor. This is seen through to show the positional relationship.
[6] Conventional X-axis linear motor movable elements there is shown a state in which the lift moves to the top position relative to the stator, (a) represents a front view thereof, (b) its It is a side view.
[7] be those conventional X-axis linear motor mover showing a state in which the lift moves to the bottom position relative to the stator, (a) represents a front view thereof, (b) its It is a side view.
[Explanation of symbols]
1 X-axis linear motor (linear motor of the present invention)
2 Field yoke 3 Permanent magnet 4 Yoke base 5 Armature 6 Coil array 7 Frame 8 Cooling jacket 10 Z-axis linear motor 11 Z-axis actuator 12 Slider 13 Guide rail 14 Moving stage 15 Fixed base

Claims (1)

And from configured stator field yoke that is arranged in a straight line a plurality of permanent magnets constituting the field pole so different polarities alternately, via the magnet array and the magnetic air gap of the permanent magnet, the magnet array toward the longitudinal and a more composed mover and frame made of an insulating material made of ceramic for supporting armature and said armature having a coil array that facing each of the fixed base An X-axis linear motor configured to travel relative to the field pole and the armature so as to be reciprocally movable in the X-axis direction that is horizontal with respect to
A moving stage provided on an upper part of the frame of the X-axis linear motor for placing a workpiece or the like;
A Z-axis linear motor which is arranged on both sides of the X-axis linear motor on the fixed base and is provided so as to be movable in the Z-axis direction which is perpendicular to the fixed base; ,
A linear guide provided between the Z-axis linear motor and the fixed base;
In a stage apparatus equipped with
The permanent magnet has a length in a direction orthogonal to the longitudinal direction in which the magnet array is arranged larger than a length in a direction orthogonal to the longitudinal direction of the armature of the coil array,
The stage apparatus has a cooling jacket for exchanging heat generated by the coil of the armature with a refrigerant in the frame so as to prevent thermal deformation of the moving stage.

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