CN103573815B - Micropositioner and gas bearing - Google Patents

Abstract

The invention provides a micro-motion table and an air bearing. The micro-motion table adopts a support tile type static pressure air bearing to support and guide the silicon wafer or glass substrate on the micro-motion table with high precision. The unit performs Z, θx, θy, and θz micro-stroke movements on the micro-motion plate. The pad-type static pressure air bearing includes a fixed shaft of the bearing and several pad devices evenly arranged around the fixed shaft. In the pad device An air film is formed by ventilation with the fixed shaft of the bearing, the pad device can move together with the micro-motion table, and the manufactured air film can also be inclined accordingly to play the role of support and guidance.

Description

Micro motion table and air bearing

technical field

The invention relates to a photolithography process, in particular to a micro-motion stage and an air bearing.

Background technique

The micro-motion stage of the lithography machine mainly carries silicon wafers or glass substrates for Z, θx, θy, θz micro-stroke movements, and performs precise positioning, so as to realize real-time focusing and leveling functions for silicon wafers or glass substrates. In order to achieve high positioning accuracy, the micro-motion table adopts air bearings to support and guide silicon wafers or glass substrates.

The air bearing of the micro-motion table in the prior art uses a one-dimensional rotating flexible part as the air bearing guide, and at the same time, the air flow must enter the gap between the flexible part and the ring stator through the flexible part to form an air film, and the thickness of the air film is It is not adjustable and cannot compensate for manufacturing and installation errors, and this air bearing only has one-dimensional rotational flexibility in the radial direction, which cannot meet the precise positioning of four degrees of freedom, and because the airflow channel passes through different flexible parts, it will cause each flexible Differences in component sensitivity.

Contents of the invention

The object of the present invention is to provide a micro-motion table and an air bearing to support a silicon chip or a glass substrate and guide its movement.

In order to solve the above technical problems, the present invention provides an air bearing, which is arranged between the base of the micro-motion table and the micro-motion plate, and the micro-motion plate can perform Z, θx, θy, and θz microstroke movements, so The air bearing includes a fixed shaft of the bearing and several pad devices, the fixed shaft of the bearing is fixedly arranged on the base, an opening is provided on the fretting plate, and the end of the fixed shaft of the bearing away from the base passes through The opening, the plurality of pad devices are arranged outside the outer circumference of the fixed shaft of the bearing, and the plurality of pad devices are connected to the fretting plate, the direction of the air film generated by the air bearing and The thickness can vary with the position of the fretting plate.

Optionally, each of the plurality of pad devices includes a pad, a first joint, a support, a screw and a fixing seat, and the shape of the side of the pad close to the fixed shaft of the bearing is the same as that of the fixed shaft of the bearing. Matching, the first joint is arranged on the pad, the side of the pad away from the fixed axis of the bearing is connected to the support, the screw is passed through the support and connected to the support The seat is connected by threads, and the fixed seat fixes the screw on the micro-movement plate, and the screw rotates around its own central axis on the fixed seat to drive the pad to move along the central axis After reaching the required gap between the shoe block and the fixed shaft of the bearing, the support is connected to the fretting plate.

Further, the pad device further includes a locking screw, the locking screw is arranged in the support, and is used to prevent the screw rod from rotating.

Further, the tile device further includes a hinge, and the tile is connected to the support through the hinge.

Further, the hinge is a flexible hinge.

Further, the support is connected to the micro-movement plate through screws, and the support is provided with a waist-shaped hole, and the screw is placed in the waist-shaped hole, and the screw can be placed in the waist-shaped hole. move within.

Optionally, the plurality of pad devices all include a pad, a first joint, a support, a fixed block and a screw, and the shape of the side of the pad close to the fixed shaft of the bearing is the same as the shape of the fixed shaft of the bearing. Matching, the first joint is arranged on the pad, and the side of the pad away from the fixed axis of the bearing is connected to one end of the screw, and the screw passes through the fixed block and is connected to the fixed block. The fixed block is connected by thread, the fixed block is arranged on the support, and the screw rod rotates around its own central axis on the fixed seat to drive the tile to move along the central axis to reach the After determining the required gap between the pad and the shaft of the bearing, connect the support to the fretting plate.

Further, the pad device further includes a nut, and the nut is used to lock the screw rod.

Further, the number of the nuts is two, which are respectively arranged on both sides of the fixing block, and the screw rod is locked by the two nuts.

Further, the end of the screw near the pad is provided with a ball head, and the side of the pad near the screw is provided with an inner spherical surface matching the ball head, and the ball head is placed on the In the inner spherical surface, the shoe can freely rotate around the center of the ball head without detaching from the screw.

Further, the pad device further includes a second joint, the second joint is arranged on the pad, and the end of the second joint that is in contact with the pad communicates with the inner spherical surface.

Further, the pad device also includes a pressing block, which is fixed on the pad at a position close to the ball head, which is used to limit the movement of the ball head and prevent the pad from breaking away from the ball head. screw.

The present invention also provides a micro-movement table, which includes the above-mentioned air bearing, a micro-motion plate, a base and a driving motor unit, the air bearing is fixedly arranged on the base, and the micro-motion plate passes through The driving motor group is connected with the base, and the driving motor group can drive the micro-movement plate to perform Z, θx, θy, θz micro stroke movements.

Further, the drive motor set includes a Z-direction motor and a θz motor, both of which are arranged between the micro-movement plate and the base.

Further, the driving motor unit further includes a gravity compensator, and the gravity compensator is arranged between the micro-movement plate and the base.

Further, the number of the Z-direction motors is three, the number of the θz motors is two, the number of the gravity compensators is three, and the θz motors are symmetrically arranged on both sides of the air bearing , the three Z-direction motors and the three gravity compensators are symmetrically arranged in a triangular shape on two corners and opposite sides between the micro-movement plate and the base.

Compared with the prior art, the present invention has the following beneficial effects:

The invention provides a micro-motion table and an air bearing. The micro-motion table uses a support tile type static pressure air bearing to support and guide the silicon wafer or glass substrate on the micro-motion table with high precision. The unit performs Z, θx, θy, and θz micro-stroke movements on the micro-motion plate. The pad-type hydrostatic air bearing includes a fixed shaft of the bearing and several pad devices evenly arranged around the fixed shaft. In the pad device An air film is formed by ventilation with the fixed shaft of the bearing, the pad device can move together with the micro-motion table, and the manufactured air film can also be inclined accordingly to play the role of support and guidance.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing:

FIG. 1 is a schematic structural diagram of a micro-motion stage provided by an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of an air bearing provided by an embodiment of the present invention;

Fig. 3 is a schematic structural diagram of the pad device in the air bearing provided by Embodiment 1 of the present invention;

Fig. 4 is a cross-sectional view of the pad device in the air bearing provided by Embodiment 1 of the present invention;

Fig. 5 is a schematic structural view of the pad device in the air bearing provided by Embodiment 2 of the present invention;

Fig. 6 is a cross-sectional view of the pad device in the air bearing provided by Embodiment 2 of the present invention.

In Figures 1 to 6,

1: Air bearing; 11: Bearing fixed shaft; 12: Pad device; 121: Pad; 122: First joint; 123: Support; 124: Screw; 125: Fixed seat; 126: Screw; 127: Lock Tight screw; 128: hinge; 129: waist hole; 121': tile; 122': first joint; 123': support; 124': screw; 125': fixed block; 126': screw; 127' : nut; 128′: ball head; 129′: pressing block; 2: micro-motion plate; 21: opening; 3: base; 4: drive motor unit; 41: Z-direction motor; 42: θz motor; 43: gravity compensation device.

detailed description

The micro-motion stage and the air bearing provided by the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. Advantages and features of the present invention will be apparent from the following description and claims. It should be noted that the drawings are all in a very simplified form and use imprecise ratios, which are only used to facilitate and clearly assist the purpose of illustrating the embodiments of the present invention.

The core idea of the present invention is to provide a micro-motion stage and an air bearing, the micro-motion stage adopts a shoe-type static pressure air bearing to support and guide the silicon wafer or glass substrate on the micro-motion stage with high precision For work, the micro-movement plate is moved in Z, θx, θy, θz direction by using the driving motor group. The pad type static pressure air bearing includes a fixed shaft of the bearing and several pad devices evenly arranged around the fixed shaft. Air is formed between the pad device and the fixed shaft of the bearing to form an air film, the pad device can move together with the micro-motion table, and the manufactured air film can also tilt accordingly to play the role of support and guidance .

Please refer to Figures 1 to 6, Figure 1 is a schematic structural view of a micro-motion stage provided by an embodiment of the present invention; Figure 2 is a schematic structural view of an air bearing provided by an embodiment of the present invention; Schematic diagram of the structure of the pad device in the air bearing; Figure 4 is a cross-sectional view of the pad device in the air bearing provided in Embodiment 1 of the present invention; Figure 5 is the structure of the pad device in the air bearing provided in Embodiment 2 of the present invention Schematic diagram; FIG. 6 is a cross-sectional view of the pad device in the air bearing provided by Embodiment 2 of the present invention.

Embodiment one

Please refer to Fig. 1. As shown in Fig. 1, the embodiment of the present invention provides a micro-motion stage, which includes an air bearing 1, a micro-motion plate 2, a base 3 and a drive motor unit 4. The floating bearing 1 is fixedly arranged on the base 3, and the micro-movement plate 2 is connected to the base 3 through the driving motor unit 4, and the driving motor unit 4 can drive the micro-moving plate 2 to make Z, θx , θy, θz move towards the micro stroke, and the direction and thickness of the air film generated by the air bearing 1 can change with the change of the position of the fretting plate 2 .

Further, the driving motor group 4 includes three Z-direction motors 41, three gravity compensators 43 and two θz motors 42, and the Z-direction motors 41, gravity compensators 43 and θz motors 42 are all arranged on the Between the micro-movement plate 2 and the base 3, and rigidly connected with the micro-motion plate 2 and the base 3, it is used to drive the micro-motion plate 2 and the objects on it to do Z, θx, θy, and θz directions. stroke movement, the θz motor 42 is symmetrically arranged on both sides of the air bearing 1, and the three Z-direction motors 41 and the three gravity compensators 43 are symmetrically arranged in a triangular shape between the fretting plate 2 and the On the two corners and opposite sides between the base 3, the three Z-direction motors 41 and three gravity compensators 43 are used to drive one side or the whole of the micro-movement plate 2 to move along the Z-direction, so that the The micro-movement plate 2 can move in Z, θx, and θy directions, and the gravity compensator 43 can also play the role of shock absorption and buffering to prolong the service life of the micro-motion table. The two θz motors 42 are driving Forces are respectively applied to the micro-movement plate 2 along two opposite directions of the Y-axis to make it move along the θz direction.

Please refer to Fig. 2, as shown in Fig. 2, the embodiment of the present invention also provides an air bearing 1, the air bearing 1 includes a bearing fixed shaft 11 and several pad devices 12, the bearing fixed shaft 11 is fixed Set on the base 3, the fretting plate 2 is provided with an opening 21, the end of the bearing fixed shaft 11 away from the base 3 passes through the opening 21, and the plurality of tile devices 12 are arranged around On the outside of the outer circumference of the bearing fixed shaft 11, the plurality of pad devices 12 are connected to the fretting plate 2, and air is ventilated between the pad device 12 and the bearing fixed shaft 11 to form an air film, The air film can support and guide the objects on the micro-motion platform 2 .

Please refer to Fig. 3 and Fig. 4 emphatically. As shown in Fig. 3 and Fig. 4, the several tile devices 12 all include a tile 121, a first joint 122, a support 123, a screw 124, a fixing seat 125 and a screw 126, The shape of the side of the pad 121 close to the bearing fixed shaft 11 matches the shape of the bearing fixed shaft 11 at the corresponding position, the first joint 122 is arranged on the pad 121, and the pad The side of the block 121 away from the fixed shaft 11 of the bearing is connected to the support 123, the screw 124 is penetrated in the support 123 and is threadedly connected with the support 123, and the fixed seat 125 connects the support 123 to the support 123. The screw 124 is fixed on the micro-movement plate 2, and the screw 124 can rotate around its own central axis on the fixed seat 125 to drive the pad 12 to move along the central axis to reach the After the required gap between the block 12 and the fixed shaft 11 of the bearing, the support 123 is connected to the micro-movement plate 2 through the screw 126, and the screw 126 is arranged on the support 123, and the micro-movement Corresponding positions of the moving plate 2 are provided with threaded holes corresponding to the screws 126 .

Further, the pad device 12 further includes a locking screw 127, the locking screw 127 is arranged in the support 123, and is used to prevent the screw rod 124 from rotating.

Further, the tile device 12 further includes a hinge 128 , and the tile 121 is connected to the support 123 through the hinge 128 .

Further, the hinge 128 is a flexible hinge.

Further, the support 123 is provided with a waist-shaped hole 129 , the screw 126 is placed in the waist-shaped hole 129 , and the screw 126 can move in the waist-shaped hole 129 .

By rotating the adjusting screw 124, the support 123 is moved in the radial direction, so that the gap between the side of the pad 121 close to the fixed shaft 11 of the bearing and the fixed shaft 11 of the bearing is generated to the required distance, and locked with the locking screw 127 Adjust the screw rod, the waist-shaped hole 129 arranged on the support 123 can make the screw 126 move therein, and make it move to the corresponding threaded hole, and then screw the screw 126 into the corresponding screw thread on the micro-movement plate 2 The support 123 is fixed in the hole. When the micro-motion table is working, start each Z-direction motor 41 and θz motor 42, and open the air circuit at the same time, the compressed air passes through the first joint 122 of each tile device 12, enters the tile 121, and flows between the fixed shaft 11 and the tile. A certain thickness of air film is formed between 121 to bear the load. At this time, under the drive of each motor, guided by the shoe-type static pressure air bearing 1, the micro-movement plate 2 moves in Z, θx, θy, θz to the micro-stroke, because the shoe block 121 is flexibly connected with the flexible hinge 128, During the movement, the shoe block 121 is free to incline as the load changes, so as to realize high-precision guiding and positioning. When there is a sudden gas failure, loosen the screw 126, remove the fixing seat 125, rotate the adjusting screw 126, and remove the tile 121 to avoid damaging the bearing surface of the tile 121.

Embodiment two

The difference between the micro-motion table and the air bearing provided in the embodiment of the present invention and the micro-motion table and the air bearing in the first embodiment is: Please refer to Fig. 5 and Fig. 6, as shown in Fig. 5 and Fig. 6, the The above-mentioned several pad devices all include a pad 121', a first joint 122', a support 123', a fixed block 125', a screw 124' and a screw 126', and the pad 121' is close to the fixed shaft 11 of the bearing. The shape of that side matches the shape of the bearing fixed shaft 11 at the corresponding position, the first joint 122' is arranged on the pad 121', and the side of the pad 121' away from the bearing fixed shaft 11 One side is connected to one end of the screw rod 124', the screw rod 124' is passed through the fixing block 125' and is threadedly connected with the fixing block 125', and the fixing block 125' is arranged on the support 123', the screw 124' can rotate around its own central axis on the fixed seat 125' to drive the pad 12 to move along the central axis, so as to reach the After the required gap between them, the support 123' is connected to the micro-movement plate 2 through the screw 126', and the screw 126' is arranged on the support 123', and the micro-motion plate 2 A threaded hole corresponding to the screw 126' is provided at the corresponding position.

Further, the pad device 12 further includes two nuts 127', and the two sides of the fixing block 125' are respectively locked to the screw rod 124' by the two nuts 127'.

Further, the end of the screw 124' close to the pad 121' is provided with a ball head 128', and the side of the pad 121' close to the screw 124' is provided with a ball head 128' that matches the ball head 128'. The inner spherical surface of the spherical head 128' is placed in the inner spherical surface, and the pad 121' can freely rotate around the center of the spherical head 128' without detaching from the screw rod 124'.

Further, the pad device 12 also includes a second joint (not shown in the figure), the second joint is arranged on the pad 121 ′, and the end of the pad 121 in contact with the inner The spheres are connected.

Further, the pad device 12 also includes a pressing block 129', the pressing block 129' is fixed on the pad 121' at a position close to the ball head 128', which is used to limit the ball head 128' movement, preventing the pad 121' from detaching from the screw 124'.

According to the size of the load, turn the screw 124', and use the radial movement of the screw 124' to drive the tiles 121' to move radially together, so as to achieve the purpose of adjusting the thickness of the air film. ’, tighten the screw rod 124’ at both ends, screw the screw 126’ into the corresponding threaded hole on the micro-movement plate 2, and at the same time, the compressed air enters the tile through the second joint (not shown in the figure) on the tile 121′ 121' and the ball head 128' of the screw 124' and the inner spherical surface form an air film, so that the pad 121' can freely rotate with the center of the ball head 128' to adapt to the deformation or coaxial error of the fixed shaft 11 of the bearing. High-precision positioning is realized, and the shoe block 121' is not affected by frictional force when rotating, reducing its frictional damage. When working, start each Z-direction drive 41 and θz motor 42, and open the air circuit at the same time, the compressed air passes through the first joint 122' on each shoe block 121', enters the shoe block 121' of the shoe block device 12, and is fixed in the bearing. An air film with a certain thickness is formed between the shaft 11 and the pad 121 ′, so as to bear the load on the fretting plate 2 . The micro-movement plate 2 moves in Z, θx, θy, and θz directions driven by each drive motor, and the silicon chip or glass substrate on the micro-motion plate 2 can be supported and guided by the air bearing 1, so that the silicon chip or glass substrate on the micro-motion plate 2 can be supported and guided by the air bearing 1, so that the Sheets or glass substrates can move together with the micro-movement plate 2. When there is a sudden gas failure, the outer nut 127' can be unscrewed, and the screw 124' can be rotated to move the screw 124' and the tile 121' out of the fixed pair composed of the support 123' and the fixed block 125'. In order to avoid damage to the bearing surface of the pad 121'.

Compared with the micro-motion stage and the air-bearing in the first embodiment, the micro-motion stage and the air-bearing provided in the embodiment of the present invention have no changes in other structures, so details will not be repeated here.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (15)

1. a kind of air-bearing, it is arranged between the base of micropositioner and fine motion plate, and described fine motion plate can be Z, θ x, θ y, θ Z moves to micro travel it is characterised in that including bearing dead axle and some tile fragment devices, and described bearing dead axle is fixedly installed on institute State on base, described fine motion plate is provided with an opening, described bearing dead axle passes through described opening, institute away from one end of described base State some tile fragment device weeks outside the excircle of described bearing dead axle, described some tile fragment devices are all with described fine motion plate even Connect, described tile fragment device can move with described micropositioner so that described air-bearing produce the direction of air film and thickness Degree changes with the change of described fine motion Board position；

Described some tile fragment devices all include tile fragment, the first joint, bearing, screw rod and fixed seat, and described tile fragment is near described axle Hold the shape of the dead axle side and the mating shapes of described bearing dead axle, described first joint is arranged on described tile fragment, institute The side away from bearing dead axle stating tile fragment is connected with described bearing, described screw rod be arranged in described bearing and with described Seat is threaded connection, and described screw rod is fixed on described fine motion plate described fixed seat, and described screw rod is in described fixed seat Rotarily drive described tile fragment around the central shaft of its own to move along described central axis direction, reach described tile fragment and bearing dead axle it Between behind required gap, described bearing is connected to described fine motion plate.

2. according to claim 1 air-bearing it is characterised in that described tile fragment device also includes lock-screw, described lock Tight screw is arranged in described bearing, for stoping described screw rod rotation.

3. according to claim 1 air-bearing it is characterised in that described tile fragment device also includes hinge, described tile fragment lead to Cross described hinge to be connected with described bearing.

4. according to claim 3 air-bearing it is characterised in that described hinge be flexible hinge.

5. according to claim 1 air-bearing it is characterised in that described bearing pass through screw connection in described fine motion plate On, described bearing is provided with waist-shaped hole, and described screw is placed in described waist-shaped hole, and described screw can move in described waist-shaped hole Dynamic.

6. a kind of air-bearing, it is arranged between the base of micropositioner and fine motion plate, and described fine motion plate can be Z, θ x, θ y, θ Z moves to micro travel it is characterised in that including bearing dead axle and some tile fragment devices, and described bearing dead axle is fixedly installed on institute State on base, described fine motion plate is provided with an opening, described bearing dead axle passes through described opening, institute away from one end of described base State some tile fragment device weeks outside the excircle of described bearing dead axle, described some tile fragment devices are all with described fine motion plate even Connect, described tile fragment device can move with described micropositioner so that described air-bearing produce the direction of air film and thickness Degree changes with the change of described fine motion Board position；

Described some tile fragment devices all include tile fragment, the first joint, bearing, fixed block and screw rod, and described tile fragment is near described axle Hold the shape of the side of dead axle and the mating shapes of described bearing dead axle, described first joint is arranged on described tile fragment, The side away from bearing dead axle of described tile fragment is connected with one end of described screw rod, and described screw rod is arranged in described fixed block And be threaded connection with described fixed block, described fixed block is arranged on described bearing, and described screw rod is on described fixed block Rotarily drive described tile fragment around the central shaft of its own to move along described central axis direction, reach described tile fragment and bearing dead axle it Between behind required gap, described bearing is connected to described fine motion plate.

7. according to claim 6 air-bearing it is characterised in that described tile fragment device also includes nut, described nut is used In the described screw rod of locking.

8. air-bearing, it is characterised in that the quantity of described nut is two, is separately positioned on institute according to claim 7 State the both sides of fixed block, by screw rod described in two described nut checks.

9. air-bearing according to claim 6 is it is characterised in that described screw rod is provided with ball near one end of described tile fragment Head, described tile fragment is provided with, near the side of described screw rod, the Internal Spherical Surface matching with described bulb, and described bulb is placed in described interior In sphere, described tile fragment can rotate freely without deviating from described screw rod around the center of circle of described bulb.

10. air-bearing according to claim 9 is it is characterised in that described tile fragment device also includes the second joint, described Second joint is arranged on described tile fragment, and one end that it is contacted with described tile fragment is communicated with described Internal Spherical Surface.

11. air-bearings according to claim 9 it is characterised in that described tile fragment device also includes briquetting, described briquetting It is fixed on described tile fragment on the position of bulb, it is used for limiting the motion of described bulb, prevent described tile fragment from departing from institute State screw rod.

A kind of 12. micropositioners are it is characterised in that include air-bearing, fine motion plate, bottom as described in any one of claim 1 to 11 Seat and motor group, described air-bearing is fixedly installed on described base, and described fine motion plate is by described motor group It is connected with described base, described motor group can drive described fine motion plate to be Z, θ x, θ y, θ z and move to micro travel.

13. according to claim 12 micropositioner it is characterised in that described motor group includes Z-direction motor and θ z motor, Described Z-direction motor and θ z motor may be contained between described fine motion plate and described base.

14. according to claim 13 micropositioner it is characterised in that described motor group also includes gravity compensator, institute State gravity compensator to be arranged between described fine motion plate and described base.

15. according to claim 14 micropositioner it is characterised in that described Z-direction motor quantity be three, described θ z motor Quantity be two, the quantity of described gravity compensator is three, and described θ z motor is symmetrically arranged in the two of described air-bearing Side, described three Z-direction motors and three gravity compensators be all symmetrically arranged in triangular shape described fine motion plate and described base it Between two angles and opposite side on.