JPH066247B2 - Fine movement stage device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a fine movement stage apparatus applied to, for example, a semiconductor manufacturing apparatus, a precision measuring instrument such as a microscope, a high precision processing machine or the like.

<Outline of the Invention> The present invention supports a rotating base on a center column vertically installed on a mounting substrate, and disposes the mounting base, two parallel leaf springs, and a sample stage on the base, and surrounds the column to form an isometric structure. Depending on the position, a vertical fine movement mechanism for the sample stage is provided between the leaf spring and the mounting base, and a fine movement rotation mechanism for finely rotating the sample stage is provided between the mounting substrate and the rotation base, for precision work during assembly and adjustment. It is to realize high-precision vertical fine movement and high-resolution rotary fine movement of the sample stage without the need for.

<Prior Art> As a fine movement stage device of this type, as shown in FIGS. 6 to 8, for example, an outer peripheral portion of a circular leaf spring 82 is attached and fixed to an upper peripheral surface of a rising flange 81 of a housing 8 to form a circular plate. The stage 83 is located at the center of the spring 82, and the upper surface of the stage 83 is integrally fixed to the lower surface of the stage 83. The upper ends of the circular columns 85 of the armature 84 are integrally fixed to the lower surface of the horizontal substrate 86 of the armature 84. A pair of opposed ring-shaped magnetic attraction mechanisms 9 and 9a are provided with armature gaps h and h. In addition, the sample stage 83
A rotation transmission lever 87 is projectingly provided on one side thereof and is connected to a reciprocating mechanism 88 that reciprocates in the orthogonal direction. In such a stage device, when the stage 83 is finely moved vertically, the armature caps h and h are set in advance in a state where no current is applied to the magnetic attraction mechanisms 9 and 9a.
After that, the current value of the magnetic attraction mechanisms 9 and 9a is finely adjusted to finely change the armature gaps h and h, so that the stage 83 is finely adjusted in the vertical direction. When the stage 83 is finely rotated, the lever 87 is displaced by operating the reciprocating mechanism 88, and the stage 83 is supported by the support shaft 89.
Finely moves in the direction of rotation around. However, in the conventional stage apparatus described above, it is difficult to assemble the armature 84 and the pair of magnetic attraction mechanisms 9 and 9a in a completely horizontal and vertical direction. Therefore, as shown in FIG. When the attraction mechanisms 9 and 9a are tilted and fixed by θ, a force F is generated in the armature 84 by the attraction force of the magnetic attraction mechanisms 9 and 9a, and this force F is a circular leaf spring.
It acts as a bending moment M around the center of 82, and as a result, the stage 83 tilts. When the stage 83 is kept perfectly horizontal and moves slightly vertically, the bending moment M adversely affects the vertical feed-off accuracy, which contributes to deterioration of the feed accuracy. In the fine movement rotation mechanism 88,
Since the rotation transmission lever 87 protrudingly provided on the stage 83 and the actuating lever 90 of the reciprocating drive mechanism orthogonal to the rotation transmission lever 87 are always joined in an elastic state, when the stage 83 makes a vertical fine movement,
A frictional force F is generated between the levers 87 and 90, and
The stage 83, as shown by the phantom line in FIG. 7, produces fine tilt movement with the friction generating portion as a fulcrum. The fine movement of the tilt causes the horizontality of the stage to be lost, resulting in deterioration of vertical feed accuracy.

<Object of the Invention> The present invention improves the rigidity of the leaf spring and simplifies the armature gap adjustment, realizes highly precise vertical fine movement feed and rotary fine movement feed, and does not require precise assembly adjustment. A fine movement stage device is provided.

<Structure and Effect of the Invention> In order to achieve the above object, in the present invention, a rotation base is axially supported by a center column vertically installed on a mounting substrate, and the rotation base is mounted on the rotation base and the two parallel leaf springs. , The sample stage is provided, and the vertical fine movement mechanism of the sample stage is moved between the leaf spring and the rotary base, and the sample stage is finely rotated between the mounting substrate and the rotary base, corresponding to the equiangular position surrounding the column. It is equipped with a fine motion rotation mechanism.

According to the above configuration, in the present invention, the sample stage has a high rigidity against inclination due to the parallel leaf springs, and therefore, the sample stage maintains the horizontality even if the vertical acting force of the vertical fine movement mechanism is unbalanced. .

In addition, since the vertical fine movement mechanism has three sets of push-pull structure suction mechanisms that are independently arranged, the sample stage is not tilted by finely adjusting the gap between the suction mechanism facing surfaces or the armature gap. Can move vertically. Also,
Since the fine movement rotation mechanism does not have a conventional lever connecting structure, there is no fine movement inclination of the stage due to a frictional force or the like, and the sample stage always maintains a completely horizontal state.

In addition, the vertical fine movement mechanism and the fine movement rotation mechanism of the sample stage are
Since they have mutually independent structures, they do not adversely affect each other, and realize stable micro-movements respectively, and have practical effects such as improvement of operation reliability and stability.

<Description of Embodiments> FIGS. 1 and 2 show a fine movement stage device according to the present invention.

The fine movement stage device includes a center column 11 vertically installed on a mounting substrate 1, a rotation base 12 rotatably supported by the center column 11, and a parallel shaft fixed on a cylindrical portion of the rotation base 12. Two disc-shaped leaf springs 2 having a leaf spring structure 2,
3, a sample stage 4 provided on the leaf spring 3 and fixedly supporting the outer peripheral edge thereof, and arranged between the first leaf spring 2 and the mounting base 13 in correspondence with the peripheral equiangular position of the center support 11. The vertical fine movement mechanism 5 and the fine movement rotation mechanism which is provided between the mounting substrate 1 and the rotation base 12 and finely rotates the sample stage 4 including the vertical fine movement mechanism 5.

The first and second leaf springs 2 and 3 have ring-shaped mounting portions 21 and 31 in the center and a disk-shaped spring portion 2 on the outer periphery of the mounting portion.
2, 32, and mounting ring portions 23, 33 concentric with the mounting portions 21, 31 are integrally formed on the outer circumference of the spring portion.
Stack them on top of each other and mount the mounting parts 21 and 31 on the mounting base 1.
3 is fixed to the upper surface of 3 with screws, and the outer peripheral mounting ring portion 2
3, 33 are superposed, and the outer peripheral portion of the sample stage 4 is integrally connected to this portion to form a parallel spring between the mounting base 13 and the sample stage 4.

The vertical fine movement mechanism 5 is configured at an equiangular position of the circumference surrounding the center support 11, and includes three armatures 51 fixedly mounted at 120 degrees of the first leaf spring, and the mounting base 1.
Each armature 5 is attached to the arm 14 protruding from the armature 3.
3 sets of magnetic attraction mechanisms 53, 53a arranged facing each other on the upper and lower surfaces of No. 1
Consists of.

Each armature 51 is set to be completely parallel to the sample stage 4 by adhering or fixing the end mounting portion 52 to the mounting ring portion 33.

The magnetic attraction mechanism 53, 53a forming a pair is connected to the armature 51.
The armature 51 is magnetically displaced by disposing predetermined armature gaps h and h on the upper and lower surfaces thereof, and an electromagnet having a coil 56 wound around a sensor portion 55 of a yoke 54 and a permanent magnet inside. Deployed 57
The attraction mechanism has a push-pull structure, and the permanent magnet 57 constantly applies an attraction force to the armature 51.

The fine movement rotation mechanism 6 includes a linear movement mechanism 61 on the mounting substrate 1 and a transmission mechanism 67 for converting the linear movement of the mechanism into a rotation movement.
And the transmission pin 4 of the transmission mechanism 67 is attached to the rotary base 1
It is configured by connecting to 2.

The linear motion mechanism 61 is disposed on the mounting substrate 1, and has a forward-reverse rotation speed reduction motor in which a feed screw is formed on the drive shaft 63, and a slide guide 64 formed along the drive shaft 63.
The lead nut 6 is screwed to the drive shaft 63 and reciprocates by the rotational drive of the shaft 63.
5 is provided with a guide pin 66, and the lower end is a sliding guide 64.
And the transmission mechanism 67 is attached to the shaft of the pin 66.
Are connected.

The transmission mechanism 67 includes a thin hinge portion 70 on one side of the fixed portion 69.
A transmission member 68 integrally formed with a movable portion 71 is provided to fix the fixed portion 69 vertically on the mounting substrate 1, and the movable portion 71 has a lever 72 integral with the movable portion 71 and a lever 72 facing the lever 72. It has a leaf spring elastic piece 73, and the guide pin 66 is engaged and held between the lever 72 and the elastic piece 73. A transmission pin 74 is vertically provided on the upper surface of the movable portion 71, and on the other hand, the rotation base 12 has a projection piece 1 integrated with the transmission pin 74.
5, having an elastic piece 16 made of a leaf spring facing the projecting piece 15,
The transmission pin 74 is engaged and gripped between the elastic piece 16 and the projecting piece 15 to form a transmission mechanism. When the lead nut 65 moves in the axial direction, the movable portion 71 supports the elbow portion 70 as a fulcrum. The sample stage 4 is finely rotated by the connection of the transmission pin 74 and the rotation base 12.

FIG. 4 shows an example of an exciting circuit for the magnetic attraction mechanisms 53, 53a in the fine movement stage device of the present invention. Three pairs of electromagnetic coils 56, 56a are connected in series to the power supply circuit 58, and variable resistors R ₁ , R ₂ , R ₃ are connected in parallel to the paired electromagnetic coils 56, 56a, respectively. The armature gaps h and h are adjusted by changing the value of the current flowing through the magnetic attraction mechanisms 53 and 53a.

FIG. 5 shows another embodiment of the parallel leaf springs 2 and 3 in the fine movement stage device of the present invention. In this embodiment, the first plate spring 2 is integrally formed with a central ring-shaped mounting portion 21, a strip-plate-shaped spring portion 22 radially protruding to the outer periphery of the mounting portion, and a mounting ring portion 23 surrounding the spring portion 22. In the structure, a second disk-shaped plate spring 3 similar to the above-mentioned example is superposed on the first plate spring 2. The second leaf spring 3 may of course have the same structure as the first leaf spring.

However, when assembling the fine movement stage device of the present invention, the magnetic pole surfaces g, g are preliminarily parallel to each other so that the push-pull characteristics, that is, the load current-attraction force characteristics, match the three magnetic attraction mechanisms 53, 53a. After aligning and positioning the armature 51 between them, the pair of magnetic attraction mechanisms 53, 53a are operated to set the upper and lower armature gaps h, h equally.

During fine adjustment of the sample stage 4, when the pair of magnetic attraction mechanisms 53, 53a are energized, the corresponding armature 51
Is slightly displaced upward or downward, and at the same time, the outer peripheral portions of the parallel leaf springs 2 and 3 are slightly displaced so that the sample stage 4 is finely adjusted in the vertical direction. At this time, to the parallel leaf springs 2 and 3,
When non-uniformity such as bending in the radial direction exists, the variable resistors R ₁ , R ₂ , and R ₃ are adjusted so that three sets of magnetic attraction mechanisms 53,
By changing the current value for 53a, the sample stage 4 is kept horizontal regardless of the nonuniformity of the parallel leaf springs 2 and 3.

Next, when adjusting the fine rotation of the sample stage 4, the motor 6
When the lead nut 65 moves in the axial direction by the operation of 2, the lead nut 65 rotates the movable body 71 linked thereto with the hinge portion 70 as a fulcrum, and the movable body 71 is linked via the transmission pin 74. The rotating base 12 is finely rotated, and therefore, the fine rotation adjustment of the sample stage 4 can be performed with high accuracy.

According to the present invention, as described above, the center support 11 is attached to the rotary base 12.
And the mounting base 13 on the base 12, two parallel leaf springs 2 and 3 on the mounting base 13, and the parallel leaf springs 2 and 3.
The sample stage 4 is mounted on the upper part, and the vertical fine movement mechanism 5, the mounting substrate 1 and the rotating base 12 of the sample stage 4 are provided between the first leaf spring 2 and the mounting base 13 in correspondence with the equiangular position surrounding the column 11. Since the fine movement rotation mechanism 6 of the sample stage 4 is provided between the two, the present invention particularly has the vertical fine movement mechanism 5 and the fine movement rotation mechanism 6 of the sample stage 4 independently configured,
There is no mutual adverse effect unlike the conventional device, and the reliability and stability of each fine movement operation are improved.

Further, according to the present invention, the armatures 51 are arranged at equiangular positions around the leaf springs 2 and 3, and each armature 51 is paired.
Since the vertical fine movement mechanism 5 is configured by disposing the push-pull structure magnetic attraction mechanisms 53 and 53a facing each other, the armature gap can be adjusted freely when the sample stage 4 is horizontally set, and the adjustment is significantly facilitated. .

Further, in the present invention, since two parallel leaf spring structures are used,
The rigidity with respect to the inclination of the sample stage 4 is high, and stable vertical fine movement is realized. Further, the fine movement rotation mechanism 6 is provided with a thin-walled elbow portion 70 in a part of the transmission mechanism 67 for converting a linear movement into a rotation movement so as to transmit power to the sample stage 4. In addition, there is no rattling at the time of fine movement rotation, stable and highly precise fine movement rotation adjustment can be performed, and the device of the present invention has many effects such as size reduction and weight reduction as compared with the conventional device. .

[Brief description of drawings]

FIG. 1 is a plan view of a fine movement stage device of the present invention, a part of which is shown in cross section, FIG. 2 is a cross sectional view taken along the line II-II of FIG. 1, FIG. FIG. 5 is a diagram showing a circuit configuration example of a magnetic attraction mechanism, FIG. 5 is a perspective view showing another embodiment of a parallel leaf spring, FIG. 6 is a plan view of a conventional fine movement stage device, and FIG. 7 is VII in FIG. FIG. 8 is a cross-sectional view taken along line VII, and FIG. 8 is an explanatory diagram of the operation of the conventional device. 1 ... Mounting board 11 ... Center support 12 ... Rotating base 13 ... Mounting base 2 ... 1st leaf spring 21 ... Mounting section 22 ... Spring section 23 ... Ring section 3 ... Second plate Spring 31 ・ ・ ・ Mounting part 32 ・ ・ ・ Spring part 33 ・ ・ ・ Ring part 4 ‥‥ Sample stage 5 ‥‥ Vertical fine movement mechanism 51 ‥‥ Armature 53 ‥‥ Magnetic adsorption mechanism 6 ‥ Fine movement rotation mechanism 61 ・ ・ ・ Linear movement mechanism 67 Transmission mechanism 74 Transmission pin

Claims (4)

[Claims] 1. A center support column vertically provided on a mounting substrate, a rotation base supported by the center support column, a mounting base fixedly mounted on the rotation base, and a parallel plate mounted on the mounting base. The two leaf springs constituting the spring, the leaf spring, the sample stage provided on the leaf spring and supporting the outer peripheral portion, the leaf spring and the mounting base corresponding to the peripheral equiangular position of the center column. A fine movement stage device comprising a vertical fine movement mechanism arranged between the mounting substrate and a rotation base, and a fine movement rotation mechanism for finely rotating a sample stage including the vertical fine movement mechanism. 2. The vertical fine movement mechanism has a push-pull structure in which armatures are provided at 120 ° equiangular positions on the outer circumference of a leaf spring, and a mounting frame faces each armature with a predetermined armature gap above and below each armature. The fine movement stage device according to claim 1, wherein a pair of magnetic attraction mechanisms are provided. 3. A fine movement rotation mechanism, wherein a linear movement mechanism and a transmission mechanism for converting the linear movement into a rotation movement are provided on a mounting substrate, and a transmission pin is connected to a rotation base. The fine movement stage device described. 4. The parallel leaf spring has a ring-shaped mounting portion in the center,
The fine movement stage device according to claim 1, wherein a disk-shaped or radially protruding strip-shaped spring portion is formed on the outer periphery of the mounting portion, and a mounting ring portion is integrally formed on the outer periphery of the spring portion.