KR100507840B1 - Dual servo xy stage using leaf spring guide - Google Patents

Abstract

The present invention relates to a dual servo XY stage using a leaf spring guide for biaxial movement related to precision scanning or fiber alignment of a microscope, and more particularly, by symmetrically arranging the auxiliary motion portion and the leaf spring inwardly of the case. It relates to a double-servo XY stage using a leaf spring guide that ensures characteristics and stable motion and prevents parasitic motion in other directions besides the X and Y directions by configuring the X stage and the Y stage on the same plane. Dual-servo XY stage using a leaf spring guide according to a preferred embodiment of the present invention and the X-axis auxiliary movement unit which is installed opposite to the inside of the case; A plurality of first leaf springs disposed opposite the X-axis auxiliary movement part so as to be perpendicular to the X-axis direction; An X-axis main movement unit installed between the first plate springs adjacent to each other in the X-axis direction and having an inner space; And an X stage installed in the first plate spring adjacent to one side of the X axis main movement part and fixed to one side of the case and contacting one side of the X axis main movement part. And Y-axis auxiliary movement units installed to face each other in the inner space of the X-axis main movement unit of the X stage. A plurality of second leaf springs disposed opposite the Y-axis auxiliary movement part so as to be perpendicular to the Y-axis direction; A Y-axis main movement unit installed between the inner side second leaf springs adjacent to the Y-axis direction; And a Y stage including a Y-axis driver disposed on the second spring adjacent to one side of the Y-axis main motion part and fixed to one side of the X-axis main motion part, and contacting one side of the Y-axis main motion part.

Description

Dual servo shock stage with leaf spring guide {DUAL SERVO XY STAGE USING LEAF SPRING GUIDE}

The present invention relates to a double-servo XY stage using a leaf spring guide, and more particularly, to form an X stage for the X-axis motion and a Y stage for the Y-axis motion on the same plane and the plate spring on each stage , Symmetrical arrangement of the motor part, the auxiliary motor part to prevent the parasitic movement other than the intended direction of movement to ensure a stable movement and a double-servo XY stage using a leaf spring guide having excellent thermal characteristics.

Most high-precision scanning stages used in microscopes use hinge-type flexible mechanism and PZT. In general, however, the driving range of PZT is hard to exceed several tens of micrometers even when an amplifying structure is used. Therefore, a stage capable of driving an area of several mm or more with a nm resolution is difficult to implement as a single servo, and thus mainly implemented using a double servo. However, since these stages are also aimed at large stages with a driving range of several hundred millimeters that can be applied in most semiconductor processes, the structure is too large and complicated to move several millimeters.

As the dual servo stage, a linear motor, a linear guide, or an air bearing guide is used as a coarse driver, and a microdriver uses a PZT and a flexible device guide. In this case, two drivers and two guide means are required, which makes the structure complicated and consequently makes it difficult to implement the double servo stage.

In addition, in the case of using the air bearing guide, since a vertical displacement other than the direction of movement occurs, an additional driver must be installed to compensate for this, which further complicates the structure of the stage. Moreover, there existed a problem that the precision of driving of a stage falls by the heat which generate | occur | produces from a linear motor.

To solve these problems, an ultra-precision stage driven by a single servo is introduced.

8 is an exploded perspective view showing a single servo stage using a conventional VCM. As shown in FIG. 8, the single servo stage 80 using the conventional voice coil motor (VCM) has each VCM 90 guided by the leaf springs 83 and 85 for axial movement and Y-axis movement. X-axis motion follows the movement of the coil of the VCM (90), Y-axis motion follows the motion of the magnet yoke assembly of the VCM (90), the X stage 82 for the X-axis motion It is a structure formed by stacking the Y stage 84 formed below and mounted on the specimen stage 91 for the Y-axis movement thereon.

The conventional single servo stage using the VCM is simplified by adopting the VCM as a single servo, but there is still a problem with the heat generated in the coil of the VCM.

In addition, since the axial stages are arranged in a stack, the center of mass of the driver does not exist on one plane, causing a pitch and a roll motion.

The present invention has been made to solve the above problems of the prior art, an object of the present invention is to implement a guide mechanism as a single leaf spring guide in order to avoid the complexity of the structure, by placing the leaf springs symmetrically and thermal properties and It is to provide a double-servo XY stage using a leaf spring guide to ensure a stable movement and to form each axial stage on the same plane to prevent the occurrence of pitch and roll motion.

An object of the present invention described above and the X-axis auxiliary movement unit which is installed opposite the inside of the case; A plurality of first leaf springs disposed opposite the X-axis auxiliary movement part so as to be perpendicular to the X-axis direction; An X-axis main movement unit installed between the first plate springs adjacent to each other in the X-axis direction and having an inner space; And an X stage installed in the first plate spring adjacent to one side of the X axis main movement part and fixed to one side of the case and contacting one side of the X axis main movement part. And Y-axis auxiliary movement units installed to face each other in the inner space of the X-axis main movement unit of the X stage. A plurality of second leaf springs disposed opposite the Y-axis auxiliary movement part so as to be perpendicular to the Y-axis direction; A Y-axis main movement unit installed between the inner side second leaf springs adjacent to the Y-axis direction; And a Y stage including a Y-axis driver disposed on the second plate spring adjacent to one side of the Y-axis main motion part and fixed to one side of the X-axis main motion part, and contacting one side of the Y-axis main motion part. It can be achieved by a double servo XY stage using a leaf spring guide.

In order to achieve the above object, a first preload spring is installed on the other side of the main shaft of the X axis to contact the main axis of the X axis, and a second preload spring is in contact with the main axis of the Y axis of the other axis of the Y axis. It is preferable to be installed.

In order to achieve the above object, it is preferable that the stiffness of the first and second preload springs is less than 1/10 of the stiffness of the first and second leaf springs.

In order to achieve the above object, the X-axis or Y-axis driver is preferably composed of a DC motor linear actuator coupled to the PZT on one side.

In order to achieve the above object, one end of the PZT is preferably provided with a ball coupling in contact with the X-axis or Y-axis main movement.

Other objects, specific advantages and novel features of the invention will become more apparent from the following detailed description and the preferred embodiments associated with the accompanying drawings.

Hereinafter, a configuration of a dual servo XY stage using a leaf spring guide according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing a double servo XY stage using a leaf spring guide according to a preferred embodiment of the present invention, Figure 2 is a perspective view showing a configuration of a double servo XY stage using a leaf spring guide according to a preferred embodiment of the present invention to be. As shown in Figure 1 and 2, the dual servo XY stage using the leaf spring guide according to the present invention is the X-axis auxiliary movement portion 11, the X-axis main movement portion 20 and the first inward of the case (1) An X stage 10 including a leaf spring 16 and an X axis driver 40 is installed, and the Y axis auxiliary motion part 51, the Y axis main motion part 57, and the second axis are installed on the X axis main motion part 20. The Y stage 50 including the leaf spring 56 and the Y axis driver 70 is disposed at 90 ° with the X stage 10, and the case 1 is covered with a cover 2 penetrating the center thereof. .

3 is a perspective view showing an X stage constituting a double-servo XY stage using a leaf spring guide according to a preferred embodiment of the present invention. As shown in FIG. 3, in the X stage 10 constituting the dual-servo XY stage according to the present invention, two X-axis auxiliary motion parts 11 are symmetrically inside the case 1 having a rectangular inner space. Is installed. Four first plate springs 16 are coupled to the X-axis auxiliary movement unit 11, and the first plate springs 16 coupled to the respective X-axis auxiliary movement units 11 are symmetric with each other.

Between the four first leaf springs 16 located inside the X-axis main movement portion 20 of the rectangular box type having an upper portion and having an inner space 21 is installed. The X axis main motion part 20 has an outer protrusion 22 at a portion where the first leaf springs 16 extend to engage the first leaf spring 16 to the outside and the Y stage 50 on the inner side thereof. An inner protrusion 23 is provided for installation, and a through hole is formed in one of the inner protrusions 23, and an end of the first leaf spring 16 is engaged with the outer protrusion 22 of each of the X-axis main motion parts 20. Fixed blocks 30 and 33 are coupled to each other.

The ends of the first leaf springs 16 located at the leftmost side are engaged between the two fixing blocks 31 and 32, and the outer fixing block 32 is fixed to the case 1, and the inner fixing block is fixed to the case 1. A first preload spring 37, which is a coil spring, is installed between the 31 and the fixed block 30 of the main X-axis main motion unit 20. It is preferable that the rigidity of the first preload spring 37 based on the direction of the linear motion is 1/10 or less of the rigidity of the first leaf spring 16.

The ends of the first leaf springs 16 located at the far right are also engaged between the two fixing blocks 34 and 35, and the outer fixing block 35 is fixed to the case 1. The fixing blocks 34 and 35 have a through portion (not shown) formed in the center thereof, and the X-axis driver 40 penetrates the through portion.

4 is a perspective view showing a Y stage constituting a double-servo XY stage using a leaf spring guide according to a preferred embodiment of the present invention. As shown in FIG. 4, in the Y stage 50 constituting the dual-servo XY stage according to the present invention, two Y-axis auxiliary movement parts 51 are installed in the inner space of the X-axis main motion part 20. Four second plate springs 56 are coupled to the Y-axis auxiliary movement unit 51, and the second plate springs 56 coupled to each of the Y-axis auxiliary movement units 51 are disposed symmetrically with each other.

Between the two second plate springs 56 located inside, a Y-axis main movement part 57 having a mounting hole 58 for mounting a specimen stand or the like is installed thereon. The end of the second leaf spring 56 is superimposed on the outer surface of the Y-axis main motion portion 57 and the fixing blocks 60 and 63 are coupled.

The upper ends of the second leaf springs 56 located between the two fixing blocks 61 and 62 are engaged, and the upper fixing block 62 is fixed to the case 1, A second preload spring 67, which is a coil spring, is installed between the fixed block 61 and the fixed block 60 of the adjacent Y-axis main motion 57.

The lower ends of the second leaf springs 56 are also engaged between the two fixing blocks 64 and 65, of which the lower fixing block 65 is fixed to the case 1. The fixing blocks 64 and 65 have a through portion (not shown) formed in the center thereof, and a Y-axis driver 70 penetrates the through portion.

5 is a perspective view showing the coupling structure of the leaf spring of the dual-servo XY stage using a leaf spring guide according to a preferred embodiment of the present invention. As shown in FIG. 5, the leaf spring 16 of the dual-servo XY stage according to the present invention is inserted into and fixed to the clamp 13 of the auxiliary movement part 11, and occurs in a portion exposed from the auxiliary movement part 11. The edge of the clamp 13 is chamfered to relieve stress concentration. The coupling structure of this leaf spring is the same in the X stage and the Y stage.

Since the X-axis driver 40 and the Y-axis driver 70 used in the dual-servo XY stage according to the present invention have the same configuration, only the X-axis driver 40 will be described below.

Figure 6 is a perspective view showing the driver of the dual servo XY stage using a leaf spring guide according to a preferred embodiment of the present invention. As shown in FIG. 6, the X-axis driver 40 used in the dual-servo XY stage according to the present invention is installed in the driving main body 41 and the driving main body 41 fixed to the penetrating portion of the fixed block and rotates. The DC motor linear actuator 42 and the PZT 43 for converting the linear motion into a combination are combined. The PZT 43 is attached to the end of the DC motor linear actuator 42 exposed from the driving body, and at the end of the PZT 43 there is a ball coupling 44 in contact with the fixed block installed in the X-axis main movement part 20. Is installed. The DC motor linear actuator 42 drives the linear motion of about several millimeters and the PZT 43 drives the linear motion of several tens of micrometers.

Hereinafter, the operation of the dual servo XY stage using the leaf spring guide according to a preferred embodiment of the present invention having the above configuration will be described in detail.

In the dual-servo XY stage according to the present invention, the X stage 10 for the X-axis movement and the Y stage 50 for the Y-axis movement are combined on the same plane, and each stage has one axis because it has an independent driver. The motion in the direction does not affect the motion in the other axial direction. However, the final motion intended by the dual servo XY stage is made by the Y-axis main motion part 57.

Since the Y stage 50 is installed in the X axis main motion part 20 of the X stage 10, the X axis motion of the Y axis main motion part 57 is X of the X stage 10 in which the Y stage 50 is installed. It is made by the axial main motion portion 20, the Y-axis motion of the Y-axis main motion portion 57 is made by the Y-axis main motion portion 57 of the Y stage (50).

The principle of the axial motion in which each stage is interposed with the leaf spring guide is the same and specifically, as follows.

Figure 7 is a schematic diagram showing the operating principle of the leaf spring of the dual-servo XY stage using a leaf spring guide according to a preferred embodiment of the present invention. As shown in FIG. 7, each stage of the dual-servo XY stage according to the present invention has eight leaf springs 16a, 16b, 16c, and 16d, two auxiliary motion parts 11, and one main motion part 20. It consists of.

The preload spring 37 is installed between the movable main motion portion 20 and the fixed block 31 corresponding to the fixed end to push both, thereby connecting the main motion part 20 and the auxiliary motion part 11. The leaf springs 16b and 16c are deformed to the left in a direction away from the preload spring 37 where the portion connected to the main motion part 20 is located. And the leaf springs (16b, 16c) connecting the main motion portion 20 and the auxiliary motion portion 11 is to pull the auxiliary motion portion 11 to the left, thereby connecting the auxiliary motion portion 11 and the fixed block (31, 34) Leaf springs (16a, 16d) is a portion connected to the auxiliary movement portion 11 is deformed to the left. Therefore, the initial position of the main motion portion 20 when the preload spring 37 is installed is moved to the left by a predetermined value.

This results in greatly extending the driving range of the leaf spring without departing from a certain amount of deformation. For example, if the initial position of the main motion portion is "0", the leaf spring must be deformed by "d" to generate the displacement of "d", but the initial position of the main motion portion is changed to "-d / 2". In this case, the deformation of "d / 2" to generate the displacement of "d" generates the same displacement amount, thereby reducing the burden on the leaf spring.

Therefore, by installing the preload spring to change the initial position of the leaf spring to reduce the total amount of deformation of the leaf spring to obtain excellent dynamic characteristics and stress characteristics throughout the stage.

However, since the leaf spring also elastically deforms, when the stiffness of the preload spring is large compared with the stiffness of the leaf spring, the leaf spring does not guide the accurate linear motion. It is set to less than / 10 to generate accurate linear motion.

Since the leaf springs are symmetrically formed in each stage, the rigidity of the leaf spring is small in the direction perpendicular to the leaf spring, and the rigidity of the leaf spring is very large in the horizontal direction, so that parasitic motion in an unintended direction hardly occurs. In addition, even when there is a deformation due to heat, heat deformation is canceled from each other by a symmetrical structure, thereby preventing adverse effects on movement.

However, since the rigidity of the leaf spring according to the direction can be changed by the selection of the thickness, length, width, etc. of the leaf spring, an appropriate value can be selected according to the purpose of the design.

When the driver and the fixing block are mechanically fixed to transmit the driving force, they may cause an unintentional movement when there is a misalignment between them. In the present invention, even if there is a misalignment, the ball coupling 44 The driving force is transmitted in a direction perpendicular to the fixed block, thereby preventing movement in an unintended direction.

Since the clamp portion of the auxiliary motion portion into which the leaf spring is inserted is chamfered, the stress concentration phenomenon on the leaf spring is alleviated.

In the dual-servo XY stage of the present invention, the guide structure using the leaf spring instead of the sliding guide guides the axial motion, thereby solving problems such as heat generation due to friction.

Although not shown in the preferred embodiment of the present invention, the present invention is not limited to this, and the DC motor linear actuator is provided with an encoder which is a sensor for detecting displacement, and the exact displacement of the moving part is measured by a linear scale or a laser interferometer sensor. Can be used for dual servo feedback control.

Although not specified in the preferred embodiment of the present invention, the hole formed in the case 1 through which the Y-axis driver 70 penetrates the Y-axis driver 70 in the X-axis direction along the Y stage 50. It is natural to form slightly in consideration.

According to the dual-servo XY stage using a leaf spring guide according to a preferred embodiment of the present invention having the above-described configuration, the thermal deformation is canceled out because the leaf spring and the auxiliary motion portion and the main motion portion serving as a guide are symmetrically arranged. Since the thermal properties of, and the leaf spring is very stiff except for one direction to generate almost one degree of freedom movement, there is an effect that can prevent the unintentional parasitic movement occurs.

Since the double-servo XY stage of the present invention has formed the X stage and the Y stage on the same plane, the center of gravity of each stage is located on the same plane, so that pitch and roll motion can be prevented from occurring.

Since the driver contacts the fixed block of the main motion part through the ball coupling, there is an effect that the direction of the force can be maintained almost constant even if there is a slight deviation in the alignment between the driver and the fixed block.

Since the double servo XY stage of the present invention is driven by a pushing force, the leaf spring cannot be pulled and deformed. However, since the initial position of the leaf spring is changed in the direction of the driver using the preload spring, the deformation amount of the leaf spring is constant. Yet double the amount of exercise is effective.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

1 is a perspective view showing a dual servo XY stage using a leaf spring guide according to an embodiment of the present invention,

Figure 2 is a perspective view showing the inside of the dual servo XY stage using a leaf spring guide according to a preferred embodiment of the present invention,

3 is a perspective view showing an X stage constituting a double-servo XY stage using a leaf spring guide according to an embodiment of the present invention,

4 is a perspective view showing a Y stage constituting a double-servo XY stage using a leaf spring guide according to an embodiment of the present invention,

5 is a perspective view showing the coupling structure of the leaf spring of the dual-servo XY stage using a leaf spring guide according to an embodiment of the present invention,

Figure 6 is a perspective view showing the driver of the dual servo XY stage using a leaf spring guide according to an embodiment of the present invention,

7 is a schematic view showing the operation principle of the leaf spring of the dual-servo XY stage using a leaf spring guide according to a preferred embodiment of the present invention,

8 is an exploded perspective view showing a single servo stage using a conventional VCM.

Explanation of the Main References

1: case 2: cover

10: X stage 11: X axis auxiliary motion part

16: 1st leaf spring 20: X axis main motion part

37: First preload spring 40: X-axis driver

50: Y stage 51: Y axis auxiliary motion part

56: 2nd leaf spring 57: Y axis main motion part

67: second preload spring 70: Y-axis actuator

Claims (5)

X-axis auxiliary movement parts (11) installed to face the inner side of the case (1); A plurality of first leaf springs 16 disposed opposite the X-axis auxiliary movement part 11 so as to be perpendicular to the X-axis direction; An X-axis main movement part 20 provided between the first leaf springs 16 adjacent to each other in the X-axis direction and having an inner space; And an X-axis adjacent to one side of the X-axis main motion part 20 and installed on the first plate spring 16 fixed to one side of the case 1 and in contact with one side of the X-axis main motion part 20. An X stage 10 including a driver 40; And Y-axis auxiliary movement units 51 which are installed to face in the inner space of the X-axis main movement unit 20 of the X stage 10; A plurality of second leaf springs 56 disposed opposite the Y-axis auxiliary movement part 51 so as to be perpendicular to the Y-axis direction; A Y-axis main movement part 57 provided between the inner side second leaf springs 56 adjacent to the Y-axis direction; And a second plate spring 56 adjacent to one side of the Y-axis main motion part 57 and fixed to one side of the X-axis main motion part 20, and in contact with one side of the Y-axis main motion part 57. Dual-servo XY stage using a leaf spring guide composed of a Y stage 50 including a Y-axis driver 70. The method of claim 1, A first preload spring 37 is provided on the other side of the X axis main motion part 20 to contact the X axis main motion part 20, and on the other side of the Y axis main motion part 57, the Y axis main motion part ( A double servo XY stage using a leaf spring guide, characterized in that the second pre-load spring (67) in contact with the 57). The method of claim 2, The stiffness of the first and second preload springs (37, 67) is less than 1/10 of the stiffness of the first and second leaf springs (16, 56), dual servo XY stage using a leaf spring guide. The method according to claim 1 or 2, The X-axis or Y-axis driver (40, 70) is a dual-servo XY stage using a plate spring guide, characterized in that composed of a DC motor linear actuator 42 coupled to the PZT (43) on one side. The method of claim 4, wherein Double servo XY stage using a leaf spring guide, characterized in that the ball coupling 44 is installed at one end of the PZT (43) in contact with the X-axis or Y-axis main motion portion (20, 57).