Auxiliary driving device, polishing mechanism for wafer processing and polishing equipment

Abstract

The utility model provides an auxiliary driving device, a polishing mechanism for wafer processing and polishing equipment. The auxiliary driving device comprises an auxiliary driver; the magnetic coupling mechanism comprises an electromagnetic wheel and a conductive gear opposite to the electromagnetic wheel; the electromagnetic wheel is configured to be driven to rotate by the auxiliary driver; the conductive gear is provided with a conductive disc and a gear surrounding the conductive disc, and the conductive gear is in power connection with a polishing head station switching mechanism of the polishing equipment; the electromagnetic wheel is configured to have magnetism when powered on so as to be in magnetic connection with the conductive gear, so that power of the auxiliary driver is transmitted to the polishing head station switching mechanism through the conductive gear, and polishing head station switching is conducted. According to the polishing mechanism, the polishing head station switching mechanism can be driven by the auxiliary driver to conduct polishing head station switching and posture adjustment, and the maintenance or repair convenience of the polishing mechanism is improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of semiconductor processing, and in particular to an auxiliary driving device, a polishing mechanism for wafer processing, and a polishing apparatus. BACKGROUND

[0002] In the field of semiconductor processing, a polishing apparatus is mainly used to remove excess material on the surface of a wafer or the like by chemical mechanical polishing (CMP) technology, so as to make the wafer surface highly flat, thereby facilitating subsequent processes.

[0003] Currently, a single-disk multi-head polishing apparatus is equipped with two or more polishing heads, and a controllable part of the polishing heads can polish at the polishing disk, while another part of the polishing heads can work at other stations (for example, at loading and unloading stations), so as to improve the WPH (Wafer Per Hour) of the polishing apparatus.

[0004] However, when the current single-disk multi-head polishing apparatus switches between stations, a motor is usually used to drive the linkage rotation of each polishing head through a large-speed-ratio speed reducer, so as to switch between stations. Such a large-speed-ratio structure is difficult to switch between stations or adjust the posture under the condition that the motor cannot provide power, resulting in a long time consumption for maintenance and troubleshooting. SUMMARY

[0005] Therefore, embodiments of the present application provide an auxiliary driving device, a polishing mechanism for wafer processing, and a polishing apparatus to at least partially solve the above problems.

[0006] According to an aspect of the present application, an auxiliary driving device for a polishing apparatus is provided, comprising: an auxiliary driver; and a magnetic coupling mechanism, the magnetic coupling mechanism comprising an electromagnetic wheel and a conductive gear opposite to the electromagnetic wheel; the electromagnetic wheel is configured to be driven to rotate by the auxiliary driver; the conductive gear has a conductive disc and a gear surrounding the conductive disc, and the conductive gear is power-connected with a polishing head station switching mechanism of the polishing apparatus; the electromagnetic wheel is configured to have magnetism when energized to magnetically connect with the conductive gear, so as to transmit power of the auxiliary driver to the polishing head station switching mechanism via the conductive gear, to switch between stations of the polishing head.

[0007] Optionally or alternatively, the electromagnetic wheel comprises a plurality of electromagnets uniformly distributed in the circumferential direction, and the magnetic poles of adjacent electromagnets are opposite, and the plurality of electromagnets generate corresponding magnetic fields when the electromagnetic wheel is energized.

[0008] Optionally or alternatively, the electromagnetic wheel and the conductive gear have a gap therebetween in the axial direction, the gap is configured to allow the conductive disc to be in the magnetic field generated by the plurality of electromagnets when the electromagnetic wheel is powered on, and to allow the magnetic force between the electromagnetic wheel and the conductive gear to drive the conductive gear to rotate.

[0009] Optionally or alternatively, the conductive disc is configured to be induced to generate eddy current by the rotating magnetic field of the electromagnetic wheel when the electromagnetic wheel is powered on and rotating, the eddy current causes the conductive disc to generate an induced magnetic field corresponding to the magnetic pole distribution of the magnetic field of the electromagnetic wheel, the electromagnetic wheel and the conductive gear are magnetically connected through the interaction between the magnetic field of the electromagnetic wheel and the induced magnetic field of the conductive disc.

[0010] Optionally or alternatively, the conductive disc comprises a base disc and a copper disc embedded in the base disc.

[0011] Optionally or alternatively, the electromagnetic wheel is configured to be powered off when the main driver of the polishing head station switching mechanism is in operation to drive the polishing head station switching mechanism, and to be powered on when the main driver is disabled; the auxiliary driver is configured to be activated when the main driver is disabled.

[0012] Optionally or alternatively, the auxiliary driving device further comprises a control mechanism configured to control the activation and deactivation of the auxiliary driver and to control the power on and off of the electromagnetic wheel.

[0013] Optionally or alternatively, the control mechanism is configured to control the power on of the electromagnetic wheel before controlling the activation of the auxiliary driver.

[0014] Optionally or alternatively, the auxiliary driver is a pneumatic motor or a direct current motor.

[0015] According to another aspect of the present application, there is provided a polishing mechanism for wafer processing, comprising a main driver, a polishing head station switching mechanism connected to the main driver, at least two polishing head assemblies connected to the polishing head station switching mechanism, and an auxiliary driving device as described in the foregoing aspects.

[0016] Optionally or alternatively, the main driver and the polishing head station switching mechanism are connected via a first transmission wheel and a second transmission wheel connected in series in the axial direction, the first transmission wheel is connected to the output shaft of the main driver and is meshingly connected to the conductive gear of the auxiliary driving device, the second transmission wheel is connected to the polishing head station switching mechanism, the first transmission wheel is configured to drive the second transmission wheel to rotate and in turn drive the polishing head station switching mechanism to switch the polishing head station.

[0017] Optionally or alternatively, the polishing head station switching mechanism comprises a reduction gear connected with the second transmission wheel and a rotary support mechanism configured to support the polishing head assembly.

[0018] According to another aspect of the present application, there is provided a polishing apparatus for wafer processing, comprising a polishing disc, a loading table, a dresser and a liquid supply arm, and a polishing mechanism as described in the foregoing aspects.

[0019] According to the auxiliary driving device, the polishing mechanism for wafer processing and the polishing apparatus for wafer processing of the present application, by providing the magnetic coupling mechanism capable of driving the polishing head station switching mechanism, an auxiliary way of switching the polishing head station is provided for the polishing mechanism or the polishing apparatus, ensuring the convenience of switching the polishing head station during maintenance and troubleshooting, reducing the operation difficulty of the operator, significantly shortening the downtime and improving the production capacity. Moreover, the magnetic coupling mechanism is a non-contact driving way, the electromagnetic wheel and the conductive gear are non-mechanically contacted, and there is no wear between them, so that the service life of the magnetic coupling mechanism is long, and the cost of the overall equipment is reduced.

[0020] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and are not limiting to the present application. BRIEF DESCRIPTION OF DRAWINGS

[0021] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the different views of the drawings.

[0022] Figure 1 is a structural schematic view of a polishing apparatus;

[0023] Figure 2 is a structural schematic view of a polishing apparatus according to an embodiment of the present application, which comprises an auxiliary driving device according to an embodiment of the present application;

[0024] Figure 3 is Figure 2 is a structural schematic view of a magnetic coupling mechanism of the auxiliary driving device;

[0025] Figure 4 is Figure 3 is a structural schematic view of the magnetic coupling mechanism from another angle;

[0026] Figure 5 is Figure 2 is a structural schematic view of a magnetic coupling mechanism of the auxiliary driving device, which comprises a connecting structure;

[0027] Figure 6 is Figure 5Another angle of the magnetic coupling mechanism.

[0028] Reference signs:

[0029] Polishing apparatus 100, polishing mechanism 110, liquid supply arm 120, dresser 130, polishing disc 140, loading table 150, polishing pad 160, main driver 111, polishing head station switching mechanism 113, speed reducer 1131, driving wheel of speed reducer 1131A, rotary support mechanism 1132, polishing head assembly 114, carrier head 115, auxiliary driving device 200, auxiliary driver 210, magnetic coupling mechanism 220, electromagnetic wheel 221, electromagnet 2211, conductive gear 222, conductive disc 2221, gear of conductive gear 2222, first transmission wheel 111B, second transmission wheel 111A, output shaft 111C. DETAILED DESCRIPTION

[0030] Preferred embodiments of the present application will be described in more detail with reference to the drawings. Although preferred embodiments of the present application are shown in the drawings, it should be understood that the present application can be embodied in various forms without being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0031] The terminology used in the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used in the description of the application and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0032] It will be understood that, although the terms "first", "second", "third", etc. can be used herein to describe various components, these components should not be limited by these terms. These terms are only used to distinguish one component from another. For example, a first component could be termed a second component, and, similarly, a second component could be termed a first component without departing from the scope of the present application. As such, the term "in one embodiment" is contemplated to mean that a stated feature, structure, or characteristic is included in at least one embodiment of the present application. The phrases "in one embodiment" or "in an embodiment" as used herein do not necessarily refer to the same embodiment.

[0033] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0034] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0035] In related technologies, when a single-disc multi-head polishing equipment controls the polishing head to switch between two or more workstations (such as the polishing workstation at the polishing disc and the loading and unloading workstation at the loading and unloading table), a motor is generally used in conjunction with a high-ratio reducer to drive the polishing head components to rotate in linkage and switch workstations. However, when the motor cannot provide power (such as motor failure or power failure), this high-ratio structure makes it difficult to switch workstations or adjust posture, which seriously affects the maintenance or troubleshooting of the polishing equipment.

[0036] To address the aforementioned issues, this application provides an auxiliary drive device that can assist in driving the polishing head station switching mechanism after a motor failure or power outage, thereby driving the polishing head assembly to switch stations and adjust its posture.

[0037] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0038] See Figure 1 , Figure 1 A schematic diagram of a polishing apparatus 100 suitable for use with the auxiliary drive device in an embodiment of this application is shown. As shown, the polishing apparatus 100 includes a polishing mechanism 110, a liquid supply arm 120, a dressing device 130, a polishing disc 140, and a loading stage 150. The polishing mechanism 110 may include a main drive (… Figure 1 (Not shown), polishing head station switching mechanism 113 and two polishing head assemblies 114, below the polishing head assembly 114 (relative to) Figure 1As shown in the state) provided with a carrier head 115 (or can be referred to as a polishing head), the polishing pad 140 is provided with a polishing pad 160. Two polishing head assemblies 114 are connected with the polishing head station switching mechanism 113, the main drive is connected with the polishing head station switching mechanism 113 through the polishing head station switching mechanism 113, the main drive 111 drives the polishing head station switching mechanism 113 to rotate, thereby making the two polishing head assemblies 114 switch between the polishing pad 140 and the loading table 150 two stations.

[0039] The trimmer 130 can swing around the fixed point located on the left side of the polishing pad 140 (relative to the state shown) to trim the surface of the polishing pad 160. The trimmer 130 is configured to rotate the trimming disc itself and apply a downward load; the liquid supply arm 120 is arranged above the polishing pad 160 to spread the polishing liquid on the surface of the polishing pad 160 according to the process requirements. Figure 1

[0040] During the polishing operation, the carrier head 115 abuts the surface to be polished of the wafer and other components to the surface of the polishing pad 160, and the carrier head 115 rotates and reciprocates along the radial direction of the polishing pad 140; at the same time, the polishing pad 140 rotates, and the liquid supply arm 120 sprinkles the polishing liquid on the surface of the polishing pad 160. Under the chemical action of the polishing liquid, the wafer and the abrasive particles in the polishing liquid are relatively moved by the relative motion of the carrier head 115 and the polishing pad 140, so as to remove the material on the surface of the wafer.

[0041] In the present example, when the two polishing head assemblies 114 need to switch stations, the main drive transmits power to the polishing head station switching mechanism 113, thereby increasing the driving torque, and completing the station switching of the two polishing head assemblies 114. In addition, when one of the polishing head assemblies 114 is normally polishing, the main drive 111 and the speed reducer 1131 of the polishing head station switching mechanism 113 can also provide a large enough torque to overcome the dynamic polishing resistance and maintain the stable state of the polishing head assembly 114.

[0042] It should be noted that, Figure 1 In the example shown, two polishing head assemblies 114 are provided. It can be understood that the polishing head assembly 114 can be more than two in specific implementation, which is not limited herein.

[0043] Figure 2 ​Fig. 1 is a schematic view of a polishing mechanism for wafer processing according to an embodiment of the present application, which comprises a main driver 111, a polishing head station switching mechanism 113 connected to the main driver 111, at least two polishing head assemblies 114 connected to the polishing head station switching mechanism 113, and an auxiliary driving device 200. Specifically, the polishing head station switching mechanism 113 can comprise a speed reducer 1131 and a rotary support mechanism 1132 configured to mount the polishing head assemblies. The auxiliary driving device 200 comprises an auxiliary driver 210 and a magnetic coupling mechanism 220, which comprises an electromagnetic wheel 221 and a conductive gear 222 opposite to the electromagnetic wheel 221; the electromagnetic wheel 221 is configured to be driven to rotate by the auxiliary driver 210; the conductive gear 222 is in power connection with the polishing head station switching mechanism 113. The main driver 111 and the polishing head station switching mechanism 113 are connected via a first transmission wheel 111B and a second transmission wheel 111A connected in series in the axial direction, the first transmission wheel 111B is connected to an output shaft 111C of the main driver 111 and is in meshing connection with the conductive gear 222 of the auxiliary driving device 200, the second transmission wheel 111A is connected with the polishing head station switching mechanism 113, specifically with a driving wheel 1131A of the speed reducer 1131, the first transmission wheel 111B is configured to drive the second transmission wheel 111A to drive the polishing head station switching mechanism 113 to switch the polishing head station.

[0044] In optional embodiments, the auxiliary driver 210 is a pneumatic motor or a direct current motor.

[0045] Figure 3 For Figure 2 A schematic view of the magnetic coupling mechanism 220 of the auxiliary driving device 200 is shown; Figure 4 For Figure 3 Another schematic view of the magnetic coupling mechanism 220 is shown. As can be seen, the conductive gear 222 has a conductive disc 2221 and a gear 2222 surrounding the conductive disc. Specifically, the conductive disc 2221 can comprise a base disc and a copper disc or other disc capable of generating magnetic attraction effect embedded in the base disc. The electromagnetic wheel 221 comprises a plurality of electromagnets 2211 uniformly distributed in the circumferential direction, and the magnetic poles of adjacent electromagnets 2211 are opposite, and the plurality of electromagnets 2211 generates corresponding magnetic fields when the electromagnetic wheel 221 is energized, for example, arranged in N-S-N-S-… in the circumferential direction.

[0046] Figure 5 And Figure 6 The respective connection structures of the electromagnetic wheel 221 and the conductive gear 222 are also shown, for example, the shaft connected with the electromagnetic wheel 221 and extending upward in the figure can be the output shaft of the auxiliary driver 210, and the shaft connected with the conductive gear 222 and extending downward can be connected to the rack or housing of the polishing equipment, etc. In combination Figure 5 And Figure 6It can be seen that the electromagnetic wheel 221 and the conductive gear 222 have an axial gap therebetween, which is configured to allow the conductive disc 2221, for example, a copper disc of the conductive disc 2221, to be in the magnetic field generated by the plurality of electromagnets 2211 when the electromagnetic wheel 221 is powered, so as to be able to generate a magnetic attraction effect. The conductive disc 2221 is configured to be induced to generate an eddy current by the rotating magnetic field of the electromagnetic wheel 221 when the electromagnetic wheel 221 is powered and rotates, and the eddy current causes the conductive disc 2221 to generate an induced magnetic field corresponding to the magnetic pole distribution of the magnetic field of the electromagnetic wheel 221. Due to the same sex repulsion and the opposite sex attraction, the electromagnetic wheel 221 and the conductive gear 222 are magnetically coupled and drivenly connected through the interaction between the magnetic field of the electromagnetic wheel and the induced magnetic field of the conductive disc, and the electromagnetic wheel 221 can thereby drive the conductive gear 222 to rotate, so as to transmit the rotation of the output shaft of the auxiliary drive 210 to the conductive gear 222, and then to the polishing head station switching mechanism 113 through the first transmission wheel 111B and the second transmission wheel 111A, thereby providing auxiliary power for the polishing head station switching mechanism 113.

[0047] Further, the gap is also configured to make the magnetic force between the electromagnetic wheel 221 and the conductive gear 222 large enough to drive the conductive gear 222 to rotate to drive the polishing head station switching mechanism 113. The gap can be adjusted according to the size of the torque required to drive the polishing head station switching mechanism 113 to rotate, so as to ensure that the electromagnetic wheel 221 and the conductive gear 222 do not slip, thereby ensuring that the auxiliary drive device 200 can effectively drive the polishing head station switching mechanism 113.

[0048] In a specific implementation, the auxiliary drive device 200 and the polishing head station switching mechanism 113 can be arranged side by side, and specifically, the electromagnetic wheel 221, the conductive gear 222, and the axis of the speed reducer 1131 can be arranged in parallel.

[0049] The magnetic coupling mechanism adopted in the embodiments of the present application is a non-contact driving mode, and the electromagnetic wheel and the conductive gear are not in mechanical contact, so there is no wear therebetween, which makes the magnetic coupling mechanism have a long service life and can effectively reduce the cost of the overall equipment. Moreover, the magnetic coupling mechanism has an overload protection function, which can avoid overloading failure of the polishing equipment, reduce the downtime of the polishing equipment, and improve the production capacity.

[0050] In the embodiments of the present application, the failure of the main drive 111 can include various cases such as failure, power failure, process maintenance, etc. of the main drive 111, which cannot provide power for the speed reducer 1131. For example, the case of powering off the main drive 111 to maintain one of the polishing heads in the double polishing head.

[0051] In the embodiments of the present application, when the main driver 111 cannot provide power for the speed reducer 1131, the speed reducer 1131 and the polishing head assembly 114 driven thereby can be driven by the auxiliary driver 210 to switch the work station and adjust the posture. Since the polishing mechanism with double polishing heads needs to be repeatedly maintained, or the consumables need to be replaced at a high frequency for the severe wear of the process, the auxiliary driving device of the present application can effectively improve the convenience of troubleshooting, maintenance or repair of the polishing mechanism, shorten the downtime, improve the system uptime, thereby improving the production efficiency and reducing the production loss caused by downtime.

[0052] In specific embodiments, the electromagnetic wheel 221 is configured to be not powered when the main driver 111 normally operates to drive the polishing head work station switching mechanism 113, and to be powered when the main driver 111 fails; the auxiliary driver 210 is configured to be started when the main driver 111 fails. The auxiliary driving device 200 can further include a control mechanism (not shown in the figure), which is configured to control the start and stop of the auxiliary driver 210 and the power-on and power-off of the electromagnetic wheel 221. Preferably, the control mechanism is configured to control the electromagnetic wheel 221 to be powered on before controlling the auxiliary driver 210 to be started, so that the electromagnetic wheel 221 generates a magnetic field first, which helps the electromagnetic wheel 221 and the conductive gear 222 to establish stable magnetic force coupling. Further, when the auxiliary driving is not needed, the auxiliary driver 210 can be controlled to stop first, and then the electromagnetic wheel 221 can be controlled to be powered off to disconnect the electromagnetic wheel 221 and the conductive gear 222. Through such a delay setting, the stability of the system during the start and stop switching of the auxiliary driving device can be ensured. Preferably, the controller is configured to make the main driver 111 and the auxiliary driver 210 not interfere with each other for the speed reduction polishing head work station switching mechanism 113.

[0053] In specific implementations, the control mechanism can be a controller, such as a single-chip microcomputer, a programmable logic controller, etc.

[0054] In specific implementations, the delay time at start and stop can be determined according to actual conditions, which is not limited herein.

[0055] Preferably, a switch can be further provided between the electromagnetic wheel 221 and the power supply (not shown) supplying power thereto, which is electrically connected or communicatively connected with the control mechanism and controlled thereby. The control mechanism controls the switch to power on or power off the electromagnetic wheel 221, so as to establish or cut off the magnetic force connection between the electromagnetic wheel 221 and the conductive gear 222. In addition, the power supply for the electromagnetic wheel 221 can be the original power supply in the polishing equipment, so as to reduce the introduction of additional components and simplify the system structure.

[0056] The auxiliary driving device, the polishing mechanism for wafer processing and the polishing equipment for wafer processing provided by the application can drive the magnetic coupling mechanism of the polishing head station switching mechanism, provide an auxiliary way for switching the polishing head station for the polishing mechanism or the polishing equipment, ensure the convenience of the polishing head station switching during maintenance and troubleshooting, reduce the operation difficulty of the operator, significantly shorten the downtime, and improve the production capacity. The double-driving polishing mechanism and the polishing equipment with the main driving and the auxiliary driving, the double-driving mechanism cooperates with each other, ensures the efficient operation of various stages such as the on-machine work and the downtime maintenance of the system, and improves the overall efficiency of the equipment.

[0057] Obviously, those skilled in the art can make various modifications and variations to the application without departing from the spirit and scope of the application. Thus, if these modifications and variations of the application belong to the scope of the claims of the application and the equivalent technology thereof, the application also intends to include these modifications and variations.

Claims

1. An auxiliary drive device for a polishing apparatus, characterized by, The auxiliary drive device comprises: an auxiliary drive; and a magnetic coupling mechanism comprising an electromagnetic wheel and a conductive gear wheel opposite to the electromagnetic wheel; the electromagnetic wheel is configured to be driven to rotate by the auxiliary drive; the conductive gear wheel has a conductive disc and a gear wheel surrounding the conductive disc, and is power-connected with a polishing head station switching mechanism of the polishing equipment; the electromagnetic wheel is configured to have magnetism when energized to magnetically connect with the conductive gear wheel, so as to transmit power of the auxiliary drive to the polishing head station switching mechanism via the conductive gear wheel to perform polishing head station switching.

2. The auxiliary drive device according to claim 1, characterized in that the electromagnetic wheel comprises a plurality of electromagnets uniformly distributed in the circumferential direction, and poles of adjacent electromagnets are opposite, and the plurality of electromagnets generate corresponding magnetic fields when the electromagnetic wheel is energized.

3. The auxiliary drive device according to claim 2, characterized in that a gap is provided between the electromagnetic wheel and the conductive gear wheel in the axial direction, the gap is configured to enable the conductive disc to be in the magnetic fields generated by the plurality of electromagnets when the electromagnetic wheel is energized, and the magnetic force between the electromagnetic wheel and the conductive gear wheel is capable of driving the conductive gear wheel to rotate.

4. The auxiliary drive device according to claim 3, characterized in that the conductive disc is configured to be induced to generate eddy current by the rotating magnetic field of the electromagnetic wheel when the electromagnetic wheel is energized and rotates, the eddy current causes the conductive disc to generate an induced magnetic field corresponding to the pole distribution of the magnetic field of the electromagnetic wheel, and the electromagnetic wheel and the conductive gear wheel are magnetically connected through the interaction between the magnetic field of the electromagnetic wheel and the induced magnetic field of the conductive disc.

5. The auxiliary drive device according to claim 1, characterized in that the conductive disc comprises a base disc and a copper disc embedded in the base disc.

6. The supplemental drive of claim 1, wherein, the electromagnetic wheel is configured to be de-energized when a main drive of the polishing head station switching mechanism is in operation to drive the polishing head station switching mechanism, and is energized when the main drive fails; the auxiliary drive is configured to be started when the main drive fails.

7. An auxiliary drive device according to claim 6, characterised in that the auxiliary drive device further comprises a control mechanism configured to control starting and stopping of the auxiliary drive and to control energization and de-energization of the electromagnetic wheel.

8. The auxiliary drive device according to claim 7, characterized in that the control mechanism is configured to control energization of the electromagnetic wheel before controlling starting of the auxiliary drive.

9. The auxiliary drive device according to any one of claims 1 to 8, characterized in that the auxiliary drive is a pneumatic motor or a direct current motor.

10. A polishing mechanism for wafer processing, characterized by, the polishing equipment comprises a main drive, a polishing head station switching mechanism connected with the main drive, at least two polishing head assemblies connected with the polishing head station switching mechanism, and the auxiliary drive device as claimed in any one of claims 1 to 9.

11. The polishing mechanism according to claim 10, wherein the main drive and the polishing head station switching mechanism are connected via a first transmission wheel and a second transmission wheel axially connected in series, the first transmission wheel is connected to an output shaft of the main drive and is meshingly connected with the conductive gear wheel of the auxiliary drive device, the second transmission wheel is connected with the polishing head station switching mechanism, and the first transmission wheel is configured to drive the second transmission wheel to rotate and in turn drive the polishing head station switching mechanism to perform polishing head station switching.

12. The polishing mechanism according to claim 11, wherein the polishing head station switching mechanism comprises a speed reducer connected with the second transmission wheel and a rotary support mechanism configured to support the polishing head assemblies.

13. A polishing apparatus for wafer processing, characterized by comprising: the polishing equipment comprises a polishing disc, a loading table, a dresser and a liquid supply arm, and the polishing mechanism as claimed in any one of claims 10 to 12.

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