WO2019137496A1

WO2019137496A1 - Lifting mechanism, lifting platform device, lithography machine and lithography method

Info

Publication number: WO2019137496A1
Application number: PCT/CN2019/071446
Authority: WO
Inventors: 管博然; 黄亚庆; 丛国栋
Original assignee: 上海微电子装备（集团）股份有限公司
Priority date: 2018-01-12
Filing date: 2019-01-11
Publication date: 2019-07-18
Also published as: TW201930173A; CN110028008A

Abstract

Disclosed is a lifting mechanism, a lifting platform device, a lithography machine, and a lithography method. The lifting mechanism comprises a case (4), a worm (1), a worm wheel (2), and a lead screw (3), wherein when rotating, the worm (1) drives the worm wheel (2) to rotate, and the lead screw (3) is driven, by means of the rotation of the worm wheel (2), to move up and down in the vertical direction. The lifting mechanism can simultaneously meet the requirements of highly precise and large-load vertical lifting adjustment in a limited space, and uses an anti-rotation limiting mechanism to prevent the lead screw (3) from rotating such that the output power of the worm wheel (2) and the worm (1) is completely received by the lead screw (3), and the range of motion of the lead screw (3) is also limited, so that the entire transmission mechanism is more efficient and reliable. The lifting mechanism compensates for the lack of high-precision, large-load and small-sized lifting mechanisms in the prior art, and is applied to, for example, the field of lithography machines, and the lithography effect thereof can also be correspondingly improved.

Description

Lifting mechanism, lifting table device, lithography machine and lithography method

Technical field

The present invention relates to the field of semiconductor manufacturing technology, and in particular, to a lifting mechanism, a lifting platform device, a lithography machine, and a lithography method.

Background technique

The lifting mechanism is a common mechanism that can be used to lift people or goods to a certain height and can be applied to many fields. For example, in the field of semiconductor manufacturing, the lifting mechanism is applied to the workpiece table of the lithography machine by fixing The base of the workpiece table can be used to support and adjust the entire maglev module.

However, due to the size limitation of the former lithography machine, the installation position and space of the lifting mechanism are very limited. Under this premise, the requirements for adjustment accuracy, stability and reliability are also high. At the same time, the lifting mechanism is also required to withstand a large load of, for example, 1.5 tons. At present, all the lifting platform systems found on the market cannot meet the demand and are far from each other. In addition, the inventors consulted a number of well-known lift platform manufacturing companies that can carry out custom lift service, and were told that it is impossible to manufacture a suitable lift system that satisfies both high precision, large load and small size. Therefore, there is an urgent need for a lifting mechanism capable of achieving high precision, large load, and high reliability in a limited space to fill the gaps in high-precision, large-load, and small-sized lifting mechanisms on the market.

Summary of the invention

In order to solve the technical problem of currently lacking a lifting mechanism capable of realizing high precision, large load and high reliability in a limited space, the present invention provides a lifting mechanism including a box body, a worm, a worm wheel and a screw rod The worm and the worm wheel are disposed in the casing, the worm is engaged with an external thread of the worm wheel, the worm wheel is sleeved on the screw rod and the screw rod and the worm wheel are disposed inside Threaded, the lead screw is vertically disposed and extends from the casing to the outside of the casing; the worm is rotatable to drive the worm gear to rotate, and the screw is driven by the rotation of the worm wheel Lifting in the straight direction.

Optionally, an anti-rotation limiting slot is disposed on a sidewall of the screw shaft protruding from the worm wheel, and the housing is provided with a jack corresponding to the position of the anti-rotation limiting slot, The lifting mechanism further includes a slider, the slider is inserted into the insertion hole and is locked in the anti-rotation limit groove, and the anti-rotation limit groove, the insertion hole and the slider constitute the wire Rod anti-rotation limit mechanism.

Optionally, the anti-rotation limit mechanism is included.

Optionally, the two anti-rotation limit mechanisms are included.

Optionally, the two anti-rotation limiting mechanisms are symmetrically disposed about a central axis of the screw.

Optionally, the transmission ratio of the worm wheel and the worm is 1:40 to 1:120.

Optionally, the internal thread of the worm wheel has a pitch of less than 2 mm.

Optionally, the lifting mechanism further includes a plurality of worm wheel bearings, wherein the plurality of worm wheel bearings are disposed in the box body, and are respectively disposed above and below the worm wheel in a vertical direction, and are located at the worm wheel The worm gear bearing below supports the worm gear.

Optionally, the worm wheel bearing abuts the worm wheel to maintain a predetermined gap between the worm wheel and the box.

Optionally, the worm wheel bearing is a crossed roller bearing.

Optionally, the lifting mechanism further includes a plurality of worm bearings, wherein the plurality of worm bearings are disposed in the casing, and are sleeved on the worm along a length direction of the worm to be radially limited Position the worm.

Optionally, the worm bearing is a radial ball bearing.

Optionally, the box body includes an upper side box body and a lower side box body, wherein the upper side box body and the lower side box body respectively cover the worm wheel from above and below the worm wheel, wherein Conical pin holes are respectively disposed at corresponding positions of the upper side case and the lower side case, and a conical pin is inserted in the conical pin hole to make the upper side case and the lower side The cabinet is aligned and fixed.

Optionally, the lower side box includes:

In a first part, the first portion includes an arcuate groove for covering the worm from below the worm;

a second part, the second part comprising a disk-shaped support and an auxiliary support for covering the worm wheel from below the worm wheel;

The disc-shaped support member and the side walls of the arcuate groove are connected to each other in a horizontal direction, the auxiliary support member is disposed below the disc-shaped support member, a bottom portion of the auxiliary support member and the curved shape The bottom of the trough is on the same level;

The auxiliary support member is disposed at a junction of the disc-shaped support member and the arcuate groove, and is coupled to the arcuate groove to increase a connection between the disc-shaped support member and the arcuate groove Thickness size.

The invention also provides a lifting platform device comprising:

The lifting mechanism provided by the present invention,

The working platform is disposed above the screw rod in the lifting mechanism and connected to the top end of the screw rod, and the lifting and lowering of the working platform is realized by lifting and lowering the screw rod.

The present invention also provides a lithography machine employing the lift table apparatus provided by the present invention.

The present invention also provides a photolithography method using the photolithography machine provided by the present invention.

The invention provides a lifting mechanism which adopts a transmission mechanism of a combination of a worm, a worm wheel and a screw rod. The overall structure is simple and reliable, and can meet the requirements of vertical lifting adjustment of high precision and large load in a limited space. Moreover, the present invention further adopts an anti-rotation limit mechanism to prevent the screw from rotating so that the output of the worm wheel and the worm is completely received by the screw rod, and at the same time limits the range of motion of the screw rod, so that the entire transmission mechanism has higher efficiency. And reliability. The invention provides a lifting mechanism, which compensates for the vacancy of the high-precision, large-load and small-sized lifting mechanism in the prior art, and is applied to, for example, the field of a lithography machine, and the lithography effect thereof can be correspondingly improved.

DRAWINGS

1 is a view showing the overall structure of a lifting mechanism in a first embodiment of the present invention;

2 is a schematic structural view of a transmission mechanism according to Embodiment 1 of the present invention;

3 and 4 are cross-sectional views of the elevating mechanism in the first embodiment of the present invention;

Figure 5 is a simulation diagram of the safety factor of the lower casing in the first embodiment of the present invention;

6 is a simulation diagram of displacement of a lower casing in the first embodiment of the present invention;

7 and 8 are cross-sectional views of the elevating mechanism in the second embodiment of the present invention;

Figure 9 is a schematic view showing the comparison of the structure of the lower case before and after reinforcement in the second embodiment of the present invention;

10 is a simulation diagram of the safety factor of the improved lower casing in the second embodiment of the present invention;

Figure 11 is a simulation diagram of the displacement of the improved lower casing in the second embodiment of the present invention.

Detailed ways

The lifting mechanism, the lifting platform device, the lithography machine and the lithography method proposed by the present invention are further described in detail below with reference to the accompanying drawings and specific embodiments. Advantages and features of the present invention will become more apparent from the description. It should be noted that the drawings are in a very simplified form and all use non-precise proportions, and are only for convenience and clarity to assist the purpose of the embodiments of the present invention.

Embodiment 1

1 is a schematic structural view of a lifting mechanism according to a first embodiment of the present invention, FIG. 2 is a schematic structural view of a transmission mechanism according to a first embodiment of the present invention, and FIGS. 3 and 4 are cross-sectional views of the lifting mechanism according to the first embodiment of the present invention. 1 to 4, in this embodiment, a lifting mechanism is provided, the lifting mechanism comprising a box 4, a worm 1, a worm wheel 2 and a screw rod 3; the worm 1 and the worm wheel 2 are disposed in the same In the case 4, the worm 1 is coupled with the external thread of the worm wheel 2, and the internal thread of the worm wheel 2 is sleeved on the screw rod 3. The screw rod 3 is vertically disposed and self-described The casing 4 extends to the outside of the casing 4; when the worm 1 rotates, the worm wheel 2 is driven to rotate, and the worm wheel 2 is rotated to drive the screw rod 3 to move up and down in the vertical direction.

The following is shown with reference to Figure 2 to illustrate the transmission process of the transmission mechanism of the present invention. The worm 1 is horizontally disposed and coupled with the external thread of the worm wheel 2; the screw rod 3 is vertically disposed; the inner ring of the worm wheel 2 is provided with a worm wheel internal thread and is sleeved on the screw rod 3. It can be seen that when the worm 1 is rotated, due to the connection with the external thread of the worm wheel 2, the axial rotation of the worm 1 along its central axis is converted into the axial rotation of the worm wheel 2 along its central axis, and the worm wheel 2 passes through the worm wheel. The thread is connected to the screw rod 3, and the rotation of the worm wheel 2 is converted into a vertical movement of the screw rod 3, and if the load is placed on the top of the screw rod 3, the load can be lifted and lowered by the screw rod 3. Moreover, since the worm wheel, the worm, and the screw have a small size and volume, the lifting mechanism constituted by the worm wheel has a small volume correspondingly. For example, its overall volume may be less than 160 mm (length) x 120 mm (width) x 40 mm (height).

In the embodiment, the box body 4 includes an upper side box 401 and a lower side box 402, and the upper side box 401 and the lower side box 402 are respectively covered from above and below the worm wheel 2. The worm wheel 2. Specifically, the upper side box 401 further has an upper cover portion, and the upper cover portion covers a part of the screw rod 3 to provide sufficient space for subsequently forming an anti-rotation limit mechanism; further, FIG. 5 and FIG. 6 are In the first embodiment of the present invention, a safety factor simulation diagram and a displacement simulation diagram of the lower casing, as shown in FIG. 5 and FIG. 6, the lower casing 402 includes a first portion 4020 and a first portion connected to the first portion 4020. The second portion 4021 is for covering the worm 1 from below the worm 1, and the second portion 4021 is for covering the worm wheel 2 from under the worm wheel 2. Specifically, the topography of the first portion 4020 and the second portion 4021 can be respectively matched with the worm 1 and the worm wheel 2. For example, the first portion 4020 includes a curved groove, and the second portion 4021 includes a disk-shaped support and an auxiliary support, the side walls of the curved groove and the disk-shaped support are connected to each other in a horizontal direction, An auxiliary support is disposed below the disc-shaped support and the bottom of the auxiliary support and the bottom of the arcuate groove of the first portion 4020 are on the same level.

As a preferred solution, an anti-rotation limiting slot 301 is disposed on a sidewall of the lead screw 3 extending from the worm wheel, and the anti-rotation limiting slot 301 is disposed on the housing 4 a corresponding jack, the lifting mechanism further includes a slider 5, the slider 5 is inserted into the jack and is locked in the anti-rotation limiting slot 301, and the anti-rotation on the screw rod 3 The rotation limit groove 301, the insertion hole on the casing 4, and the slider 5 constitute an anti-rotation limit mechanism of the screw shaft 3.

Referring to FIG. 2, in the embodiment, one anti-rotation limit mechanism is provided. Thereby, it is possible to avoid/reduce the problem caused by the frictional force existing between the internal thread of the worm wheel 2 and the screw shaft 3. Specifically, when the worm wheel 2 rotates, the screw 3 can be prevented from being rotated and rotated together with the worm wheel 2 due to the frictional force, thereby improving the rotation of the output of the worm 1 and the worm wheel 2 into the lifting movement of the screw rod 3. The ability to improve the transmission efficiency of the entire transmission mechanism, at the same time, the lifting and lowering displacement of the screw rod 3 can be controlled, greatly improving the adjustment precision of the transmission mechanism. It can be seen that, by using the anti-rotation limit mechanism shown in this embodiment, the screw rod 3 is fixed radially with respect to the box body 4, and does not generate unnecessary rotation, thereby having higher transmission efficiency and drooping. Adjust the accuracy.

Further, the transmission ratio range of the worm wheel 2 and the worm 1 is, for example, 1:40 to 1:120, and the pitch of the external thread of the worm wheel 2 is preferably less than 2 mm. Since the worm wheel 2 and the worm 1 have a large gear ratio, it is possible to achieve a more precise angle of rotation of the worm wheel 2 under the large-angle rotary worm 1. Moreover, the pitch of the thread of the screw 3 and the internal thread of the worm wheel 2 is small, for example, less than 2 mm, and accordingly, the lifting and lowering of the screw 3 can be controlled more precisely.

In a specific embodiment, when the transmission ratio of the worm wheel 2 and the worm 1 is 1:80, when the thread of the screw 3 and the internal thread of the worm wheel 2 have a pitch of 1 mm, the When the worm 1 rotates one turn, the worm wheel 2 rotates correspondingly by 1/80 turn, and the screw rod 3 also rotates by 1/80 turn with respect to the worm wheel 2, and the rising height is a pitch of 1/80, that is, 12.5μm, which realizes the adjustment of the lifting and lowering size of the screw 3 with greater precision.

In addition, in actual operation, the rotation angle of the worm 1 can be further controlled to be small, for example, the worm 1 can only be rotated by 1°, and then the screw 3 can only generate a lifting of 34.7 nm correspondingly, thereby showing that The lifting mechanism provided in the embodiment has a high vertical adjustment accuracy.

It should be noted that, according to specific needs, those skilled in the art can also adjust the transmission ratio of the worm wheel 2 and the worm 1 and the pitch of the screw rod 3 accordingly, and the vertical adjustment precision will also change accordingly. Therefore, the vertical adjustment accuracy described in this embodiment is only a reference, and does not limit the range of vertical adjustment accuracy that can be achieved by the present invention.

Preferably, the lifting mechanism further includes a plurality of worm wheel bearings 6 disposed in the casing 4 and disposed above and below the worm wheel 2 in the vertical direction, respectively. The worm wheel bearing 6 located below the worm wheel 2 supports the worm wheel 2. The worm wheel bearing 6 abuts against the worm wheel 2 to maintain a predetermined gap between the worm wheel 2 and the casing 4.

Specifically, in the embodiment, a worm wheel bearing 6 is disposed above and below the worm wheel 2, and the worm wheel bearing 6 is disposed to maintain a predetermined gap between the worm wheel 2 and the box body 4, Therefore, the problem that the worm wheel 2 and the casing 4 are rubbed during the transmission process to reduce the transmission efficiency and reduce the adjustment precision of the lifting mechanism is avoided. At the same time, the worm wheel bearing 6 abuts the worm wheel 2 from above and below the worm wheel 2, so that the position of the worm wheel 2 relative to the box 4 is fixed, and wherein the worm wheel bearing 6 below the worm wheel 2 is Withstand greater pressure and play the role of supporting the worm gear 2.

As a preferred solution, the worm wheel bearing 6 is a crossed roller bearing.

In the present embodiment, it can be understood that since the worm wheel bearing 6 under the worm wheel 2 functions to support the worm wheel 2, the pressure of the load is also transmitted to the worm wheel bearing 6 under the condition of applying a load. Therefore, in order to better adapt to the working condition of the worm wheel 2, it is preferred to take a bearing with a strong bearing capacity and a high rotation precision, that is, a cross roller bearing, and the thickness dimension of the cross roller bearing can be controlled to be better than other bearings. Smaller, the installation space is further saved, and the height of the lifting mechanism is reduced.

Preferably, the lifting mechanism further includes a plurality of worm bearings 7 disposed in the casing 4 and sleeved on the worm 1 along the length of the worm 1 Upper, the worm 1 is limited in the radial direction. The worm bearing 7 is a radial ball bearing.

In this embodiment, as shown in FIG. 3, the worm bearing 7 is disposed in the casing 4 and is sleeved on the worm 1 along the length direction of the worm 1 to limit the worm. 1. The worm bearing 7 also serves to support the worm 1 to prevent the worm 1 from rubbing against the casing 4, resulting in a problem of reduced transmission efficiency and reduced adjustment accuracy. Considering the working condition of the worm 1, it is preferable to take a radial ball bearing with a weak bearing capacity but a higher rotation speed and a lower noise.

Moreover, other components are also used in the embodiment to increase the reliability of the entire lifting mechanism. For example, an oil-free bushing 8 is disposed on the top of the upper casing 401 for lifting the axial guiding precision of the screw shaft 3; A sealing ring groove is disposed on the inner side of the upper side casing 401 and the inner side of the lower side casing 402 for placing the sealing ring; and the upper and lower sides of the laminated structure of the worm wheel 2 and the worm wheel bearing 6 are respectively disposed a worm wheel cover 9 is provided, and a seal ring groove is disposed on the worm wheel cover 9 for placing a sealing ring; a gasket 10 is disposed on an outer side of the worm bearing 7 at both ends of the worm 1 and passes through the nut 11 The limit position is fixed, and the worm shaft 1 is further provided with a regular hexagonal worm adjusting device 12 to facilitate precise rotation of the worm 1 by means of the regular hexagonal worm adjusting device 12, thereby facilitating adjustment of the lifting height of the screw rod 3.

In addition, the inventors performed strength check on the combination of the worm wheel 2 and the worm 1 in the lifting mechanism, the screw rod 3 and the screw thread, and the results show that the lifting mechanism can be used without exceeding the allowable stress of each component. To achieve the lifting of the 1.5t load.

In summary, the lifting mechanism provided in the embodiment has the advantages of simple structure and high reliability, that is, in a limited space, under the premise that the force of each transmission component does not exceed its allowable stress. (For example, 160mm × 120mm × 40mm space), achieving a large load of 1.5t and high-precision lifting movement.

Embodiment 2

In this embodiment, based on a lifting mechanism provided in the first embodiment, structural improvements are made to make it better suited to actual use.

7 and 8 are cross-sectional views of the elevating mechanism in the second embodiment of the present invention, which are shown below with reference to Figs. 2, 7, and 8. As a modification of the first embodiment, two anti-rotation limiting mechanisms 13 are disposed on the lifting mechanism, and the two anti-rotation limiting mechanisms 13 are symmetrically disposed about a central axis of the screw rod 3.

Specifically, the anti-rotation limiting mechanism 13 is composed of an anti-rotation limiting slot, a jack and a slider, that is, an anti-rotation limiting slot is symmetrically disposed on both sides of the screw rod 3, in two places. A jack is also formed at the position of the upper box 401 corresponding to the anti-rotation limit slot. When the anti-rotation limit is performed, a slider 5 is inserted into the two jacks and is locked to the anti-rotation limit. In the bit slot. Since the slider 5 and the screw rod 3 are actually a key connection when the anti-rotation limit is performed, the slider is subjected to a large torque, and in this embodiment, a double-key method with higher strength is adopted, thereby Enhanced the effect of anti-rotation limit.

As another modification of the first embodiment, a tapered pin hole is disposed at a corresponding position of the upper side case 401 and the lower side case 402, and a taper pin 15 is inserted into the taper pin hole. The upper side case 401 and the lower side case 402 are aligned and fixed. Dividing the box into two parts is convenient for processing and assembly, and also for distinguishing functions that can be realized by each component.

Specifically, referring to FIG. 8 , since the box body 4 is composed of the upper side box body 401 and the lower side box body 402, and the upper and lower parts have different coaxiality tolerance requirements, that is, for example, up and down The coaxiality of the two-part circular area is required, and can be completed once during processing, so that the coaxiality and consistency during processing and subsequent assembly can be well ensured. Therefore, in the embodiment, the conical pin holes are provided at corresponding positions of the upper side case 401 and the lower side case 402. When the processing is assembled, the alignment and fixing of the upper and lower side cases can be realized by inserting the conical pin 15. , thereby improving the processing accuracy and reducing the processing difficulty.

And, in the present embodiment, referring to FIG. 7, after analyzing the structure of the worm wheel bearing 6 at the worm wheel 2, it is found that the bearing fixing module 14 of the worm wheel bearing 6 can be removed, thereby further reducing the The vertical size of the lifting mechanism.

As a preferred solution, in the embodiment, the structure of the lower side box 402 is strengthened. FIG. 9 is a schematic view showing the structure comparison of the lower side box before and after reinforcement in the second embodiment of the present invention, and FIG. 10 and FIG. In the second embodiment of the present invention, the safety factor simulation diagram and the displacement simulation diagram of the lower casing are improved. As shown in FIG. 9 to FIG. 11, the first portion 4020 and the second portion 4021 of the lower casing 402 are connected to each other. The auxiliary support of the second portion 4021 is further extended at a junction of the first portion 4020 and the second portion 4021 and connected to the first portion 4020 such that the first portion 4020 and the second portion 4021 The joint has a larger thickness dimension (ie, the thickness of the joint of the first portion 4020 and the second portion 4021 is the total thickness of the disc-shaped support and the auxiliary support of the first portion 4020), thereby enabling the lift mechanism The lower case 402 can withstand a large pressure and has a high safety factor.

Based on the lifting mechanism described above, the embodiment further provides a lifting platform device, including:

The above lifting mechanism,

In this embodiment, a lithography machine based on the above lifting platform device is further provided. Specifically, the lifting platform device is applied to a workpiece table system of a lithography machine, and the workpiece table system can achieve higher precision. With the operation of a larger load, and further, the photolithography method using the photolithography machine can also have higher precision and improve the quality and efficiency of photolithography.

In summary, the present invention provides a lifting mechanism, a lifting table device, a lithography machine, and a lithography method. The lifting mechanism has a simple and reliable structure, and can simultaneously achieve high precision and large load vertical direction in a limited space. Lift adjustment. Moreover, the present invention further adopts an anti-rotation limit mechanism, so that the entire transmission mechanism has higher efficiency and reliability. The lifting mechanism provided by the invention compensates for the vacancy of the high-precision, large-load and small-sized lifting mechanism in the prior art, and is applied to, for example, the field of a lithography machine, and the lithography effect thereof can be correspondingly improved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and the modifications

Claims

A lifting mechanism, characterized in that the lifting mechanism comprises a box body, a worm, a worm wheel and a screw rod; the worm shaft and the worm wheel are both disposed in the box body, and the worm rod is matched with the external thread of the worm wheel The worm wheel is sleeved on the screw rod and the screw rod cooperates with an internal thread of the worm wheel, the screw rod is vertically disposed and extends from the tank body to the outside of the box body; the worm rod Rotating to drive the worm wheel to rotate, and driving the screw rod in the vertical direction by the rotation of the worm wheel.
The lifting mechanism according to claim 1, wherein the side wall of the screw rod protruding from the worm wheel is provided with an anti-rotation limit groove, and the box body is provided with the anti-rotation limit a jack corresponding to the position of the slot, the lifting mechanism further includes a slider, the slider is inserted into the jack and is locked in the anti-rotation limit slot, the anti-rotation limit slot, the plug The hole and the slider constitute an anti-rotation limit mechanism of the screw.
The lifting mechanism according to claim 2, comprising one of said anti-rotation limiting mechanisms.
The lifting mechanism according to claim 2, comprising two of said anti-rotation limiting mechanisms.
The lifting mechanism according to claim 4, wherein the two anti-rotation limiting mechanisms are symmetrically disposed about a central axis of the screw.
The lifting mechanism according to claim 1, wherein the worm wheel and the worm have a transmission ratio ranging from 1:40 to 1:120.
The lifting mechanism according to claim 1, wherein the internal thread of the worm wheel has a pitch of less than 2 mm.
The lifting mechanism according to claim 1, wherein the lifting mechanism further comprises a plurality of worm wheel bearings, wherein the plurality of worm wheel bearings are disposed in the casing and are respectively disposed in the vertical direction Above and below the worm gear, the worm gear bearing below the worm wheel supports the worm gear.
The elevating mechanism according to claim 8, wherein said worm wheel bearing abuts said worm wheel to maintain a predetermined gap between said worm wheel and said casing.
The lifting mechanism according to claim 8, wherein the worm wheel bearing is a crossed roller bearing.
The lifting mechanism according to claim 1, wherein the lifting mechanism further comprises a plurality of worm bearings, wherein the plurality of worm bearings are disposed in the casing and are sleeved along a length of the worm On the worm, the worm is radially constrained.
The lifting mechanism according to claim 11, wherein the worm bearing is a radial ball bearing.
The lifting mechanism according to claim 1, wherein the casing comprises an upper side casing and a lower side casing, wherein the upper side casing and the lower casing are respectively from above the worm wheel and The worm wheel is covered underneath, wherein a conical pin hole is respectively disposed at a corresponding position of the upper side case and the lower side case, and a conical pin is inserted in the conical pin hole to make The upper side case and the lower side case are aligned and fixed.
The lifting mechanism according to claim 13, wherein the lower side case comprises:

In a first part, the first portion includes an arcuate groove for covering the worm from below the worm;

a second part, the second part comprising a disk-shaped support and an auxiliary support for covering the worm wheel from below the worm wheel;

The disc-shaped support member and the side walls of the arcuate groove are connected to each other in a horizontal direction, the auxiliary support member is disposed below the disc-shaped support member, a bottom portion of the auxiliary support member and the curved shape The bottom of the trough is on the same level;

The auxiliary support member is disposed at a junction of the disc-shaped support member and the arcuate groove, and is coupled to the arcuate groove to increase a connection between the disc-shaped support member and the arcuate groove Thickness size.
A lifting platform device, comprising:

A lifting mechanism according to any one of claims 1 to 14,

The working platform is disposed above the screw rod in the lifting mechanism and connected to the top end of the screw rod, and the lifting and lowering of the working platform is realized by lifting and lowering the screw rod.
A lithography machine characterized by using the lifting table apparatus according to claim 15.
A photolithography method characterized by employing the photolithography machine of claim 16.