U.S. patent application number 09/791678 was filed with the patent office on 2002-05-02 for xyz-axes table.
Invention is credited to Joong, Kim Houng, Naganuma, Ryouichi, Seino, Hiromitsu.
Application Number | 20020050804 09/791678 |
Document ID | / |
Family ID | 18815292 |
Filed Date | 2002-05-02 |
United States Patent
Application |
20020050804 |
Kind Code |
A1 |
Joong, Kim Houng ; et
al. |
May 2, 2002 |
XYZ-axes table
Abstract
The invention provides an XYZ-axes table with a linear motor.
The XYZ-axes table has a base, a plurality of linear guiding
apparatuses, a stage, an X-axis drive linear motor, a Y-axis drive
linear motor, and a Z-axis drive linear motor. The linear motor is
constituted by an armature and a movable element being capable of
relatively moving with respect to the armature. The linear motor
further has one magnetic pole teeth rows which are magnetically
connected to one magnetic pole of the armature and are arranged so
as to be separated into a first stage and a second stage in a
substantially vertical direction to a moving direction of the
movable element, and another magnetic pole teeth rows which are
magnetically connected to another magnetic pole of the movable
element and are arranged so as to be separated into a first stage
and a second stage in a substantially vertical direction to the
moving direction of the movable element, the first stage of
magnetic pole teeth in the one magnetic pole teeth rows and the
first stage of magnetic pole teeth in the another magnetic pole
teeth row are alternately arranged with respect to the moving
direction of the movable element, the second stage of magnetic pole
teeth in the one magnetic pole teeth rows and the second stage of
magnetic pole teeth in the another magnetic pole teeth row are
alternately arranged with respect to the moving direction of the
movable element, and the movable element is arranged between the
one and another first stage of magnetic pole teeth rows and the one
and another second stage of magnetic pole teeth rows.
Inventors: |
Joong, Kim Houng; (Hitachi,
JP) ; Naganuma, Ryouichi; (Hitachinaka, JP) ;
Seino, Hiromitsu; (Iwaki, JP) |
Correspondence
Address: |
ANTONELLI TERRY STOUT AND KRAUS
SUITE 1800
1300 NORTH SEVENTEENTH STREET
ARLINGTON
VA
22209
|
Family ID: |
18815292 |
Appl. No.: |
09/791678 |
Filed: |
February 26, 2001 |
Current U.S.
Class: |
318/649 |
Current CPC
Class: |
H02K 2201/18 20130101;
H02K 41/031 20130101; B23Q 1/626 20130101; B23Q 5/28 20130101 |
Class at
Publication: |
318/649 |
International
Class: |
B64C 017/06 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 2, 2000 |
JP |
2000-340365 |
Claims
What is claimed is:
1. An XYZ-axes table comprising: a base; a plurality of linear
guiding apparatuses; a stage; an X-axis drive linear motor; a
Y-axis drive linear motor; and a Z-axis drive linear motor, wherein
said linear motor is structured such as to be constituted by an
armature and a movable element being capable of relatively moving
with respect to the armature, and said linear motor further has one
magnetic pole teeth rows which are magnetically connected to one
magnetic pole of said armature and are arranged so as to be
separated into a first stage and a second stage in a substantially
vertical direction to a moving direction of said movable element,
and another magnetic pole teeth rows which are magnetically
connected to another magnetic pole of said movable element and are
arranged so as to be separated into a first stage and a second
stage in a substantially vertical direction to the moving direction
of said movable element, the first stage of magnetic pole teeth in
said one magnetic pole teeth rows and the first stage of magnetic
pole teeth in said another magnetic pole teeth row are alternately
arranged with respect to the moving direction of said movable
element, the second stage of magnetic pole teeth in said one
magnetic pole teeth rows and the second stage of magnetic pole
teeth in said another magnetic pole teeth row are alternately
arranged with respect to the moving direction of said movable
element, and said movable element is arranged between said one and
another first stage of magnetic pole teeth rows and said one and
another second stage of magnetic pole teeth rows.
2. An XYZ-axes table as claimed in claim 1, wherein the rails of
said linear guiding apparatus are arranged at four portions
comprising east, west, south and north portions of said base, said
rails are integrally formed so that the slider guided by said rail
so as to be freely moves and a relative moving direction of said
armature form a vertical angle, said movable element is connected
to said stage so as to form a cross shape, and said armature
arranged in one east-west direction and said movable element
arranged in another south-north direction are respectively driven
as an X-axis drive linear motor and a Y-axis drive linear
motor.
3. An XYZ-axes table as claimed in claim 1, wherein four rails of
said linear guiding apparatus are arranged in four portions
comprising west, east, south and north portions on said base, said
movable elements are overlapped and arranged with keeping a gap so
as to form a cross shape, the sliders guided by said rails so as to
freely move are connected to both ends thereof so that relative
moving directions between the sliders and the movable elements are
vertical with each other, said plurality of armatures are
integrally formed with said stage by being gathered to an inner
side of said linear guiding apparatus, said armature arranged in
one east-west direction and said armature arranged in another
south-north direction are respectively driven as the X-axis drive
linear motor and the Y-axis drive linear motor.
4. An XYZ-axes table as claimed in claim 1, wherein the rails of
said linear guiding apparatus are arranged in said base so that the
X and Y axes vertically cross to each other, the sliders guided by
said rails so as to freely move are integrally formed with the
armatures so that relative moving directions are vertical, said
armatures are connected to said stage so as to form an L shape, and
the armature arranged in one east-west direction and the armature
arranged in another south-north direction are respectively driven
as the X-axis drive linear motor and the Y-axis drive linear
motor.
5. An XYZ-axes table as claimed in claim 1, wherein an XY table and
a Z-axis linear guiding apparatus respectively have a function of
driving at an angle .theta..
6. An XYZ-axes table as claimed in claim 2, wherein an XY table and
a Z-axis linear guiding apparatus respectively have a function of
driving at an angle .theta..
7. An XYZ-axes table as claimed in claim 3, wherein an XY table and
a Z-axis linear guiding apparatus respectively have a function of
driving at an angle .theta..
8. An XYZ-axes table as claimed in claim 4, wherein an XY table and
a Z-axis linear guiding apparatus respectively have a function of
driving at an angle .theta..
9. An XYZ-axes table as claimed in claim 1, wherein each of the
linear guiding apparatuses is independently arranged on said base
or one-axis linear guiding apparatus is overlaid on another-axis
linear apparatus, whereby said linear motor is used.
10. An XYZ-axes table as claimed in claim 2, wherein each of the
linear guiding apparatuses is independently arranged on said base
or one-axis linear guiding apparatus is overlaid on another-axis
linear apparatus, whereby said linear motor is used.
11. An XYZ-axes table as claimed in claim 3, wherein each of the
linear guiding apparatuses is independently arranged on said base
or one-axis linear guiding apparatus is overlaid on another-axis
linear apparatus, whereby said linear motor is used.
12. An XYZ-axes table as claimed in claim 4, wherein each of the
linear guiding apparatuses is independently arranged on said base
or one-axis linear guiding apparatus is overlaid on another-axis
linear apparatus, whereby said linear motor is used.
13. An XYZ-axes table as claimed in any one of claims 1 to 12,
further comprising a closed loop control system constituted by said
linear motor, a sensor detecting a relative displacement between
said armature and said movable element and a magnetic pole, a
control portion feeding back a signal of the sensor, and a power
drive portion.
14. An XYZ-axes table as claimed in any one of claims 1 to 12,
further comprising an open loop control system constituted by said
linear motor, a control portion and a power drive portion.
15. An XYZ-axes table as claimed in any one of claims 1 to 12,
further comprising a control system constituted by said linear
motor, a power drive portion, and a control portion including
estimating means for detecting an induced voltage of said linear
motor and estimating a relative magnetic pole position between said
armature and said movable element on the basis of said voltage
detected value.
16. An XYZ-axes table as claimed in any one of claims 1 to 12,
further comprising a control system comprising a linear motor, a
power drive portion, and a control portion including estimating
means for detecting an electric current flowing through said linear
motor and estimating a relative magnetic pole position between said
armature and said movable element on the basis of said current
detected value.
17. An XYZ-axes table as claimed in any one of claims 1 to 116,
wherein a plurality of armatures of said coaxially-driven linear
motor are arranged and a pitch between magnetic pole teeth of said
adjacent different armatures is set to (k.multidot.P+P/M) {(k=0, 1,
2, . . . ), (M=2, 3, 4, . . . )} {in which k is a number freely
selected in a range that the adjacent armatures can be arranged, M
is a number of phase of the motor} when the pole pitch is set to
P.
18. An XYZ-axes table as claimed in any one of claims 1 to 17,
wherein a through hole is provided in center portions of both of
said XY table and said base.
19. An XYZ-axes table as claimed in any one of claims 1 to 18,
wherein a compression air floating function or a magnetic floating
function is provided between said base and said stage.
20. A semiconductor producing stepper apparatus, a machine tool or
an exposing apparatus having the XY table or the XYZ-axes table as
claimed in any one of claims 1 to 19.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an XYZ-axes table, and more
particularly to an XYZ-axes table used for positioning a mask in a
stepper device for producing a semiconductor, a machine tool and
the other exposure apparatus.
[0003] 2. Description of the Prior Art
[0004] In a conventional XYZ-axes table, in the case of using a
linear motor, a linear motor having a structure in which a rotary
machine is cut and opened so as to be driven in a linear
manner.
[0005] In the XYZ-axes table, since the linear motor described in
the prior art has a lot of leakage flux between an armature and a
movable element, and a magnetic attraction force is applied to a
portion between the armature and the movable element in one
direction, a great load is applied to a support mechanism of the
movable element, so that there is a problem that a strain is
generated in the structure.
SUMMARY OF THE INVENTION
[0006] An object of the present invention is to provide an XYZ-axes
table in which a magnetic attraction force generated between the
armature and the movable element is made small by reducing a
leakage of a magnetic flux passing through a portion between the
armature and the movable element.
[0007] In accordance with one aspect of the present invention,
there is provided an XYZ-axes table provided with a base, a
plurality of linear guiding apparatuses, a stage, an X-axis drive
linear motor, a Y-axis drive linear motor and a Z-axis drive linear
motor. It is desirable that the linear motor is structured such as
to be constituted by an armature and a movable element being
capable of relatively moving with respect to the armature. Further,
it is desirable that the structure is made such that the linear
motor further has one magnetic pole teeth rows which are
magnetically connected to one magnetic pole of the armature and are
arranged so as to be separated into a first stage and a second
stage in a substantially vertical direction to a moving direction
of the movable element, and another magnetic pole teeth rows which
are magnetically connected to another magnetic pole of the movable
element and are arranged so as to be separated into a first stage
and a second stage in a substantially vertical direction to the
moving direction of the movable element, the first stage of
magnetic pole teeth in the one magnetic pole teeth rows and the
first stage of magnetic pole teeth in the another magnetic pole
teeth row are alternately arranged with respect to the moving
direction of the movable element, the second stage of magnetic pole
teeth in the one magnetic pole teeth rows and the second stage of
magnetic pole teeth in the another magnetic pole teeth row are
alternately arranged with respect to the moving direction of the
movable element, and the movable element is arranged between the
one and another first stage of magnetic pole teeth rows and the one
and another second stage of magnetic pole teeth rows.
[0008] In accordance with another aspect of the present invention,
there is provided an XYZ-axes table structured such that the rails
of the linear guiding apparatus are arranged at four portions
comprising east, west, south and north portions of the base, the
rails are integrally formed so that the slider guided by the rail
so as to be freely moves and a relative moving direction of the
armature form a vertical angle, the movable element is connected to
the stage so as to form a cross shape, and the armature arranged in
one east-west direction and the movable element arranged in another
south-north direction are respectively driven as an X-axis drive
linear motor and a Y-axis drive linear motor.
[0009] In accordance with the other aspect of the present
invention, there is provided an XYZ-axes table structured such that
four rails of the linear guiding apparatus are arranged in four
portions comprising west, east, south and north portions on the
base, the movable elements are overlapped and arranged with keeping
a gap so as to form a cross shape, the sliders guided by the rails
so as to freely move are connected to both ends thereof so that
relative moving directions between the sliders and the movable
elements are vertical with each other, the plurality of armatures
are integrally formed with the stage by being gathered to an inner
side of the linear guiding apparatus, the armature arranged in one
east-west direction and the armature arranged in another
south-north direction are respectively driven as the X-axis drive
linear motor and the Y-axis drive linear motor.
[0010] In accordance with the other aspect of the present
invention, there is provided an XYZ-axes table structured such that
the rails of the linear guiding apparatus are arranged in the base
so that the X and Y axes vertically cross to each other, the
sliders guided by the rails so as to freely move are integrally
formed with the armatures so that relative moving directions are
vertical, the armatures are connected to the stage so as to form an
L shape, and the armature arranged in one east-west direction and
the armature arranged in another south-north direction are
respectively driven as the X-axis drive linear motor and the Y-axis
drive linear motor.
[0011] In accordance with the other aspect of the present
invention, there is provided an XYZ-axes table structured such that
an XY table and a Z-axis linear guiding apparatus respectively have
a function of driving at an angle .theta..
[0012] In accordance with the other aspect of the present
invention, there is provided an XYZ-axes table structured such that
each of the linear guiding apparatuses is independently arranged on
the base or one-axis linear guiding apparatus is overlaid on
another-axis linear apparatus, whereby the linear motor is
used.
[0013] In accordance with the other aspect of the present
invention, there is provided an XYZ-axes table, further comprising
a closed loop control system constituted by the linear motor, a
sensor detecting a relative displacement between the armature and
the movable element and a magnetic pole, a control portion feeding
back a signal of the sensor, and a power drive portion.
[0014] In accordance with the other aspect of the present
invention, there is provided an XYZ-axes table, further comprising
an open loop control system constituted by the linear motor, a
control portion and a power drive portion.
[0015] In accordance with the other aspect of the present
invention, there is provided an XYZ-axes table, further comprising
a control system constituted by the linear motor, a power drive
portion, and a control portion including estimating means for
detecting an induced voltage of the linear motor and estimating a
relative magnetic pole position between the armature and the
movable element on the basis of the voltage detected value.
[0016] In accordance with the other aspect of the present
invention, there is provided an XYZ-axes table, further comprising
a control system comprising a linear motor, a power drive portion,
and a control portion including estimating means for detecting an
electric current flowing through the linear motor and estimating a
relative magnetic pole position between the armature and the
movable element on the basis of the current detected value.
[0017] In accordance with the other aspect of the present
invention, there is provided an XYZ-axes table structured such that
a plurality of armatures of the coaxially-driven linear motor are
arranged and a pitch between magnetic pole teeth of the adjacent
different armatures is set to (k.multidot.P+P/M) {(k=0, 1, 2, . . .
), (M=2, 3, 4, . . . )} {in which k is a number freely selected in
a range that the adjacent armatures can be arranged, M is a number
of phase of the motor} when the pole pitch is set to P.
[0018] In accordance with the other aspect of the present
invention, there is provided an XYZ-axes table structured such that
a through hole is provided in center portions of both of the XY
table and the base.
[0019] In accordance with the other aspect of the present
invention, there is provided an XYZ-axes table structured such that
a compression air floating function or a magnetic floating function
is provided between the base and the stage.
[0020] In accordance with the other aspect of the present
invention, there is provided a semiconductor producing stepper
apparatus, a machine tool or an exposing apparatus having the XY
table or the XYZ-axes table as recited in any one of the previous
features.
[0021] The features mentioned above and the other features of the
present invention will be described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a schematic view showing a basic structure of an
XYZ-axes table with a linear motor in accordance with an embodiment
of the present invention;
[0023] FIG. 2 is a schematic view of a linear motor used in the
present invention;
[0024] FIG. 3A is a schematic view showing a notion of a magnetic
flux flow of a linear motor;
[0025] FIG. 3B is a schematic view showing an assembly constructed
by separated cores;
[0026] FIG. 4 is a schematic view showing a structure in which a
molded linear motor and a slider are combined;
[0027] FIGS. 5A and 5B are control block diagrams of a structure
using a linear motor in accordance with the present embodiment;
[0028] FIGS. 6A and 6B are another control block diagrams of a
structure using a linear motor in accordance with the present
embodiment;
[0029] FIG. 7 is a schematic view showing an XYZ-axes table with a
linear motor in accordance with an embodiment of the present
invention;
[0030] FIG. 8 is a schematic view showing an XYZ-axes table with a
linear motor in accordance with another embodiment of the present
invention;
[0031] FIG. 9 is a schematic view showing an XYZ-axes table with a
linear motor in accordance with the other embodiment of the present
invention; and
[0032] FIG. 10 is a schematic view showing an XYZ-axes table with a
linear motor in accordance with the other embodiment of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] A description will be given below of embodiments in
accordance with the present invention with reference to the
accompanying drawings.
[0034] FIG. 1 is a schematic view of a basic structure of an
XYZ-axes table corresponding to an embodiment in accordance with
the present invention.
[0035] In FIG. 1, reference numeral 101 denotes a base, reference
numeral 102 denotes a rail of a linear guiding apparatus, reference
numeral 103 denotes a stage, reference symbol 3X denotes an
armature of an X-axis drive linear motor, reference symbol 3Y
denotes an armature of a Y-axis drive linear motor, reference
symbol 3Z denotes an armature of a Z-axis drive linear motor,
reference symbols 6X, 6Y and 6Z denote a movable element in
respective axes, and reference numeral 108 denotes an arm.
Accordingly, the XYZ-axes table with the linear motor is
constituted by the elements mentioned above. The armature 3X has
portions X1 and X2. The armature 3Y has portions Y1 and Y2. The
armature 3Z has portions Z1 and Z2.
[0036] Further, a smooth movement can be achieved between the base
101 and the stage 103 in accordance with an air floating operation
or a magnetic floating operation. A portion capable moving in the X
and Y axes on the base 101 can be consumed as an XY-axes table.
[0037] FIG. 2 is a schematic view showing an embodiment of a linear
motor for driving an axis which is used in the XYZ-axes table in
accordance with the embodiment of the present invention.
[0038] In FIG. 2, the linear motor is a linear motor constituted by
an armature 3 and a movable element 6 relatively moving with
respect to the armature 3, and the linear motor further has one
magnetic pole teeth row magnetically connected to one magnetic pole
1 of the armature and arranged so as to be separated into a first
stage and a second stage in a substantially vertical direction with
respect to a moving direction of the movable element.
[0039] Further, the linear motor has another magnetic pole teeth
row magnetically connected to another magnetic pole 2 of the
movable element and arranged so as to be separated into a first
stage and a second stage in a substantially vertical direction with
respect to the moving direction of the movable element. The
oscillating type motor is structured such that the first stage
magnetic pole teeth of the magnetic pole teeth row provide in one
of them and the first stage magnetic pole teeth of the magnetic
pole teeth row provided in another thereof are alternately arranged
with respect to the moving direction of the movable element, the
second stage magnetic pole teeth of the magnetic pole teeth row
provide in one of them and the second stage magnetic pole teeth of
the magnetic pole teeth row provided in another thereof are
alternately arranged with respect to the moving direction of the
movable element, and the movable element is arranged between the
first stage magnetic pole teeth rows in one and another and the
second stage magnetic pole teeth rows provided in one and
another.
[0040] In this case, an upper magnetic pole teeth 11a and a lower
magnetic pole teeth 21b in the armature are defined as a first
opposing portion, and a lower magnetic pole teeth 12b and an upper
magnetic pole teeth 22a are defined as a second opposing portion.
Accordingly, the armature is constructed so that (2n-1)th iron core
becomes a first opposing portion and (2n)th iron core becomes a
second opposing portion (in this case, n=1, 2, 3, . . . ).
[0041] Further, one coil 4 is received in the armature 3. There is
provided a linear motor structured such that the movable element 6
is held between the first opposing portions, the movable element is
held between the second opposing portions, and the movable element
relatively moves with respect to the armature. In this case, the
armature is constituted by an iron core, a permanent magnet, and
the coil 4, and the movable element 6 may be constituted by a
permanent magnet, a magnetic body and a coil combined by one kind
or plural kinds of materials.
[0042] FIGS. 3A and 3B show schematic views showing a notion of the
magnetic flux flow of the linear motor in accordance with the
present embodiment, and an assembly constructed by laminated steel
plates. When the structure is made as shown in FIG. 2, the armature
3 in which the magnetic flux alternately flows in a vertical
direction between the upper and lower magnetic pole teeth is formed
in the gap between the upper magnetic pole teeth 11a or 22a and the
lower magnetic pole teeth 21b or 12b in the respective opposing
portions of the linear motor in accordance with the present
embodiment, whereby the movable element 6 relatively moves through
the gap, as shown in FIG. 3A.
[0043] Further, in the linear motor in accordance with the present
embodiment, since an attraction force applied to the movable
element 6 and the upper magnetic pole teeth and an attraction force
applied to the movable element 6 and the lower magnetic pole teeth
have substantially the same magnitude and the attraction forces are
applied in the opposite directions, a total attraction force
becomes small. Accordingly, it is possible to make the attraction
force between the magnetic pole teeth of the movable element 6 and
the armature 3 small, and it is possible to reduce a load of the
supporting mechanism.
[0044] In FIG. 3B, the armature is constructed by laminated steel
plates, and is structured such that plural sets of first opposing
portions and second opposing portions are alternately arranged.
Further, the magnetic pole portion (corresponding to the upper
magnetic pole teeth 11a or 22a and the lower magnetic pole teeth
12b or 21b) having the iron core portion (corresponding to the iron
core 5 in FIG. 5) in which the coil of the armature is arranged and
the opposing portions between which the movable element is held is
separately produced by the laminated steel plates and thereafter
assembled.
[0045] FIG. 4 shows an image of molding the armature constructed by
the laminated steel plates shown in FIG. 3B.
[0046] The rail 102 of the linear guiding apparatus is held between
the slide grooves 111 so as to be guided and supported in such a
manner as to be integrally formed with the slider 110 of the linear
guiding apparatus in the armature 3.
[0047] FIGS. 5A, 5B, 6A and 6B show control block diagram using the
linear motor in accordance with the present embodiment.
[0048] FIG. 5A shows a block diagram constituting a close loop
control system comprising a sensor (not shown) detecting a relative
displacement between the linear motor (Motor) constituted by the
armature and the movable element, the armature and the movable
element and the magnetic pole, the control portion (Controller)
feeding back signals (Signals) of the sensor and the power drive
portion (Driver and Power Source).
[0049] FIG. 5B shows a block diagram constituting an open loop
control system comprising the linear motor (Motor) constituted by
the armature and the movable element, the control portion
(Controller) and the power drive portion (Driver and Power
Source).
[0050] FIG. 6A shows a block diagram constituting a magnetic pole
sensorless control system comprising the linear motor (Motor)
constituted by the armature and the movable element, a voltage
sensor, the control portion (Controller) and the power drive
portion (Driver and Power Source). In the present embodiment, an
induced voltage (Eo) generated by the linear motor is read within
the control portion by using the voltage sensor. A magnetic pole
position is estimated from a magnitude of the induced voltage,
within the control portion, and a signal for driving the linear
motor is output to the power drive portion. In the control system
in accordance with the present structure, the linear motor can be
stably (without being out of step) driven without mounting a
magnetic pole position sensor in the linear motor portion.
[0051] FIG. 6B shows a block diagram constituting a magnetic pole
sensorless control system comprising the linear motor (Motor)
constituted by the armature and the movable element, a current
sensor, the control portion (Controller) and the power drive
portion (Driver and Power Source). In the present embodiment, an
electric current (I) flowing through the linear motor is read
within the control portion by using the current sensor. Within the
control portion, the induced voltage of the linear motor is
calculated from a voltage applied to the linear motor and a
detected current value, whereby the magnetic pole position is
estimated and calculated. In the control system in accordance with
the present structure, the linear motor can be stably (without
being out of step) driven without mounting the magnetic pole
position sensor to the linear motor portion.
[0052] FIG. 7 shows details of the XY table portion on the base 101
shown in FIG. 1. The XY table with the linear motor is structured
such that the rails 102 of the linear guiding apparatus are
arranged at four portions comprising east, west, south and north
portions of the base 101, the rails are integrally formed so that
the slider 110 guided by the rail so as to be freely moves and a
relative moving direction of the armature form a vertical angle,
the movable element is connected to the stage so as to form a cross
shape, and the armature arranged in one east-west direction and the
movable element arranged in another south-north direction are
respectively driven as an X-axis drive linear motor and a Y-axis
drive linear motor.
[0053] The linear motor used in the present embodiment is
structured such that an armatures 3X1 (an X1 component of the
armature 3X) and an armature 3X2 (an X2 component of the armature
3X) constitute the armature of the X-axis drive linear motor by a
form of a pair, however, the same principle can be applied to the
case of Y axis and Z axis.
[0054] In FIG. 7, in general, the armature 3X1 and the armature 3X2
are arranged in series so that a pitch between the magnetic pole
teeth of the armature 3X1 and the magnetic pole teeth of the
armature 3X2 satisfies the formula (k.multidot.P+P/M) {(k=0, 1, 2,
. . . ), (M=2, 3, 4, . . . )}. In this case, P is a pole pitch (the
pole pitch P is selected from an armature magnetic pole pitch Ps
and a movable element pole pitch Pm), and M is a number of phase of
the motor. A plurality of permanent magnets are arranged in the
movable element 6 so that the adjacent magnetic poles are
different.
[0055] In FIG. 7, the armature 3X1 and the armature 3X2 may be
arranged in series so that the pitch between the magnetic pole
teeth of the armature 3X1 and the magnetic pole teeth of the
armature 3X2 satisfies the formula {(k.multidot.P; k=0, 1, 2, . . .
)} and a plurality of permanent magnets may be arranged so that a
center of the magnetic poles between the armature 6X1 (a portion
corresponding to X1 among the armature 6X) and the armature 6X2 (a
portion corresponding to X2 among the armature 6X) satisfies the
formula (k.multidot.P+P/M).
[0056] In other words, the armatures 6X1 and 6X2 are integrally
formed by being (k.multidot.P+P/M) pitch shifted. Relatively, the
armatures 6X1 and 6X2 are aligned and the centers of the armatures
3X1 and 3X2 may be (k.multidot.P+P/M) pitch shifted.
[0057] When exciting the coils 4 of the armatures 3X1 and 3X2 so
that a moving magnetic field is alternately generated, a magnetic
flux flows in an opposite direction at every pole pitches through
the gap 8 between the upper magnetic pole surface and the lower
magnetic pole surface, a propelling force is generated due to P/2
essential for moving, the movable element 6 relatively moves, and
the stage 103 connected to the movable element freely moves.
[0058] In FIG. 7, a ferromagnetic substrate and a nonmagnetic
substrate may be combined in the movable element 6 or the permanent
magnet may be commonly used. Further, a relatively freely moving
linear motor can be obtained by winding a coil generating a moving
magnetic field around the movable element 6 in place of the
permanent magnet and flowing a field current through the armature
3.
[0059] Here, in FIG. 7, the description is given of the structure
in which two armatures are arranged in series, however, a plurality
of armatures may be arranged in series. In the same manner, the
structure may be made such that two armatures are arranged in
parallel and two movable elements are integrally formed, or a
plurality of armatures are arranged in parallel and a plurality of
movable elements are integrally formed.
[0060] In this case, the description is given of the two-phase
linear motor for the embodiment in accordance with the present
invention, however, the present invention can be used as a
multi-phase linear motor such as a three-phase, a four-phase, a
five-phase or the like.
[0061] FIGS. 8, 9 and 10 show an XYZ-axes table in accordance with
the other embodiments of the present invention.
[0062] FIG. 8 shows the other embodiment structured such that the
armatures 3X1 and 3X2 shown in FIG. 7 are gathered to one portion
in one side. The XY table with the linear motor is structured such
that the rails 102 of the linear guiding apparatus are arranged in
the base 101 so that the X and Y axes vertically cross to each
other, the sliders guided by the rails 102 so as to freely move are
integrally formed with the armatures so that relative moving
directions are vertical, the armatures 6X and 6Y are connected to
the stage 103 so as to form an L shape, and the armature 3X
arranged in one east-west direction and the armature 3Y arranged in
another south-north direction are respectively driven as the X-axis
drive linear motor and the Y-axis drive linear motor. Since the
linear motor can be combined as mentioned above, a freedom of
arrangement is improved. Further, it is possible to reduce the
number of the linear motor.
[0063] FIG. 9 shows the XY table structured such that four rails
102 of the linear guiding apparatus are arranged in four portions
comprising west, east, south and north portions on the base, the
movable elements 6X and 6Y are overlapped and arranged with keeping
a gap so as to form a cross shape, the sliders 110 guided by the
rails 102 so as to freely move are connected to both ends thereof
so that relative moving directions between the sliders and the
movable elements are vertical with each other, a plurality of
armatures are integrally formed with the stage 103 by being
gathered to an inner side of the linear guiding apparatus, the
armature 3X arranged in one east-west direction and the armature 3Y
arranged in another south-north direction are respectively driven
as the X-axis drive linear motor and the Y-axis drive linear motor.
Since the linear motor can be combined as mentioned above, it is
possible to make the wire structure simple.
[0064] FIG. 10 shows a XYZ-axes table with a linear motor
structured such that an XY table and a Z-axis linear guiding
apparatus with a tool respectively have a function of driving at an
angle .theta.. Accordingly, a freedom of working in the tool is
increased. In place of the tool, a printing apparatus and an
observing apparatus such as a microscope or the like can be
added.
[0065] Further, since a through hole is provided in center portions
of both of the XY table and the base, a long object can be mounted
on the stage. Accordingly, it is possible to expand a range of the
subject to be treated.
[0066] As mentioned above, in accordance with the embodiments of
the present invention, since the linear motor can shorten a
magnetic path of the magnetic circuit for an effective magnetic
flux and reduces a leakage flux of the magnetic pole teeth, an
efficiency can be improved. Further, in the linear motor in
accordance with the present embodiment, since the attraction force
applied to the movable element 6 and the upper magnetic pole teeth
and the attraction force applied to the movable element 6 and the
lower magnetic pole teeth have the same magnitude, and the
attraction forces are applied in the opposite directions, the whole
attraction force becomes small. Accordingly, it is possible to make
the attraction force between the magnetic pole teeth of the movable
element 6 and the armature 3 small, and it is possible to reduce a
load of the support mechanism, whereby a durability can be
improved. Further, it is possible to reduce the number of the parts
and it is possible to make the XY table thin. Further, in
accordance with the structure mentioned above, it is possible to
provide a semiconductor producing stepper apparatus having the
XYZ-axes table or the XY table, the machine tool, the exposing
apparatus or the like.
[0067] In accordance with the present invention, it is possible to
provide the XY table or the XYZ-axes table having an improved
efficiency and a high durability.
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