Electromagnetic levitation polishing head and polishing apparatus

Abstract

The application relates to an electromagnetic suspension polishing head and a polishing device, which comprises a rotating shaft, a central control system, an inductance assembly, a flexible connecting piece, a magnet assembly and an adsorption assembly. The central control system is arranged on the rotating shaft; the inductance assembly is arranged on the rotating shaft, the inductance assembly comprises a plurality of inductance units, the plurality of inductance units are used for corresponding to different areas of a substrate, each inductance unit is electrically connected with the central control system; the flexible connecting piece is arranged on the inductance assembly; the magnet assembly is arranged on the flexible connecting piece, there is a working gap between the magnet assembly and the inductance assembly, the magnet assembly is used for synchronous rotation with the inductance assembly through the flexible connecting piece, when the inductance assembly is powered, the inductance assembly and the magnet assembly form a magnetic force which attracts or repels the magnet assembly; the adsorption assembly is arranged on the rotating shaft, and the adsorption assembly is used for adsorbing the substrate. The application directly takes the electromagnetic force as a pressure source, improves the overall polishing quality while realizing the improvement of the response control.

Description

Technical Field

[0001] This application relates to the field of chemical mechanical polishing technology, and in particular to electromagnetic levitation polishing heads and polishing equipment. Background Technology

[0002] In the field of chemical mechanical polishing (CMP), existing technologies for planarization of large-size square substrates mainly employ pneumatic zoned pressurization techniques. These techniques utilize multi-layered airbags or membrane structures, introducing compressed gas into sealed chambers in different areas to drive the deformation of flexible diaphragms, thereby applying adjustable pressure to different regions of the substrate (such as the central, edge, and corner areas). For example, multiple independent annular pressurization chambers are formed by stacked membrane units, corresponding to the inner ring region and the four corner regions of the substrate, respectively.

[0003] However, this technology relies on the gas filling and releasing process. The compressibility of the gas leads to a significant response lag in pressure build-up and regulation, making it difficult to meet the needs of rapid pressure reduction or dynamic real-time adjustment after endpoint detection. Meanwhile, while existing partitioned airbags can partially improve edge effects, their limited flexibility and the number of partitions make it difficult to achieve precise independent pressure control at the four corners of a square substrate. This results in over-polishing at the corners or under-polishing at the center, affecting the overall polishing quality. Summary of the Invention

[0004] Therefore, it is necessary to provide an electromagnetic levitation polishing head and polishing equipment to address the problems of slow response and poor polishing quality in existing polishing methods.

[0005] An electromagnetic levitation polishing head, comprising:

[0006] Shaft;

[0007] The central control system is mounted on the rotating shaft;

[0008] An inductor assembly is disposed on the rotating shaft. The inductor assembly includes multiple inductor units, which are used to correspond to different areas of the substrate. Each inductor unit is electrically connected to the central control system, and the central control system is used to supply an independent control current to each inductor unit.

[0009] A flexible connector is disposed on the inductor assembly;

[0010] A magnet assembly is disposed on the flexible connector. There is a working gap between the magnet assembly and the inductor assembly. The magnet assembly is used to rotate synchronously with the inductor assembly through the flexible connector. When the inductor assembly is energized, a magnetic force is formed between the inductor assembly and the magnet assembly to attract or repel the magnet assembly.

[0011] An adsorption component is disposed on the rotating shaft, and the magnet component abuts against the adsorption component. The adsorption component is used to adsorb the substrate.

[0012] The technical solution will be further explained below:

[0013] In one embodiment, the magnet assembly includes:

[0014] The first support is connected to the flexible connector;

[0015] Multiple permanent magnets are all mounted on the first support, and each of the multiple permanent magnets corresponds to a multiple inductor unit.

[0016] In one embodiment, the inductor unit has a ring structure, and multiple inductor units are concentrically arranged around the rotating shaft.

[0017] In one embodiment, the inductor assembly includes:

[0018] The second bracket is disposed on the rotating shaft, and the flexible connector is disposed between the magnet assembly and the second bracket;

[0019] The first yoke is disposed on the second support, and the plurality of inductor units are wound around the first yoke.

[0020] In one embodiment, the first yoke is in the shape of a square ring.

[0021] In one embodiment, the adsorption component includes:

[0022] An adsorption element is disposed on the rotating shaft. An adsorption cavity is formed inside the adsorption element. A first adsorption hole is provided on the adsorption element. The first adsorption hole communicates with the adsorption cavity. The adsorption hole is used to adsorb a substrate.

[0023] An adsorption tube, one end of which is connected to the adsorption cavity;

[0024] A vacuum pump is connected to the other end of the adsorption tube.

[0025] In one embodiment, the adsorption component includes an elastic element disposed on the adsorption component, and the elastic element has a second adsorption hole that communicates with the first adsorption hole.

[0026] In one embodiment, the electromagnetic levitation polishing head includes:

[0027] A polishing housing is disposed on the rotating shaft. A first accommodating space is formed inside the polishing housing. The inductor assembly, the flexible connector, the magnet assembly, and the adsorption assembly are all located in the first accommodating space. A polishing hole is provided on the polishing housing. The polishing hole communicates with the first accommodating space. The polishing hole is used by the adsorption assembly to adsorb the substrate through the polishing hole.

[0028] A retainer is disposed on the polishing housing around the polishing hole, and the retainer is provided with grooves for guiding flow.

[0029] A polishing apparatus, comprising an electromagnetically levitated polishing head as described in any of the above claims, wherein the polishing apparatus includes:

[0030] A polishing disc is provided with a polishing surface, the polishing disc is used to rotate around the center of the polishing surface, and the polishing surface is used to polish the substrate;

[0031] A trimming device abuts against the polished surface; the trimming device is used to trim the polished surface.

[0032] A liquid supply device is used to spray polishing liquid onto the polishing surface.

[0033] In one embodiment, the polishing apparatus includes:

[0034] A polishing pad is detachably mounted on the polishing disc.

[0035] The aforementioned electromagnetic levitation polishing head and polishing equipment, after the inductor component is energized, generate a magnetic force that attracts or repels the magnet component. Since the net polishing pressure per unit area applied to the substrate is determined by the gravity of the adsorption component and the pressure exerted by the magnet component on the adsorption component, and the pressure exerted by the magnet component on the adsorption component is determined by the gravity and magnetic force of the magnet component, the magnitude and direction of the electromagnetic force can be linearly adjusted by adjusting the magnitude and direction of the current input to the inductor component, thereby precisely controlling the net polishing pressure.

[0036] This application uses electromagnetic force directly as a pressure source. By controlling the current of the inductor component to adjust the magnitude and direction of the magnetic force, millisecond-level response control can be achieved, replacing the traditional pneumatic pressurization method.

[0037] Meanwhile, each inductor unit in this application is individually controlled by the central control system. The central control system can adjust the current magnitude and direction of each inductor unit separately, thereby adjusting the magnitude and direction of the magnetic force in different areas of the substrate and optimizing the pressure distribution in each area of ​​the substrate, such as performing fine independent pressure control on the four corners of the square substrate.

[0038] Furthermore, since the inductor and magnet components can rotate synchronously with the shaft, the inductor and permanent magnet can remain relatively stationary, thereby eliminating magnetic resistance fluctuations in the magnetic circuit during rotation, stabilizing the net polishing pressure, and thus avoiding surface ripples and scratches. The partitioned control of the substrate and the synchronous rotation design of this application improve the overall polishing quality.

[0039] Therefore, this application improves the overall polishing quality while enhancing response control by directly using electromagnetic force as a pressure source. Attached Figure Description

[0040] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0041] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Furthermore, the accompanying drawings are not drawn to a 1:1 scale, and the relative dimensions of the various components are shown as examples only and not necessarily to scale. In the accompanying drawings:

[0043] Figure 1 This is a schematic diagram of the overall structure of the electromagnetic levitation polishing head.

[0044] Figure 2 This is a cross-sectional view of an electromagnetic levitation polishing head.

[0045] Figure 3 for Figure 2 Enlarged portion of the image;

[0046] Figure 4 A perspective view of the electromagnetic levitation polishing head from a low angle;

[0047] Figure 5 This is a schematic diagram of the overall structure of the polishing equipment.

[0048] Explanation of reference numerals in the attached figures:

[0049] 01. Rotating shaft; 2. Central control system; 3. Inductor assembly; 31. Inductor unit; 32. Second bracket; 33. First yoke; 41. Permanent magnet; 5. Adsorption assembly; 51. Adsorption component; 511. First adsorption hole; 52. Elastic component; 521. Second adsorption hole; 53. Support plate; 6. Limiting component; 7. Polishing shell; 8. Holding component; 81. Groove; 9. Adjusting component; 10. Polishing disc; 11. Dressing device; 12. Liquid supply device; 13. Polishing pad; 14. Base plate. Detailed Implementation

[0050] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0051] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms 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.

[0052] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0053] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," 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, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0054] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0055] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0056] See Figure 1 , Figure 2 and Figure 3 As shown, Figure 1 A schematic diagram of the overall structure of an electromagnetic levitation polishing head according to an embodiment of this application is shown; Figure 2 A cross-sectional view of an electromagnetic levitation polishing head according to an embodiment of this application is shown; Figure 3 It shows Figure 2 Enlarged view of part of the image.

[0057] An embodiment of this application provides an electromagnetic levitation polishing head, including a rotating shaft 01, a central control system 2, an inductor assembly 3, a flexible connector, a magnet assembly, and an adsorption assembly 5. The central control system 2 is mounted on the rotating shaft 01; the inductor assembly 3 is mounted on the rotating shaft 01 and includes multiple inductor units 31, each corresponding to a different area of ​​the substrate 14. Each inductor unit 31 is electrically connected to the central control system 2, which supplies an independent control current to each inductor unit 31; the flexible connector is mounted on the inductor assembly 3; the magnet assembly is mounted on the flexible connector, with a working gap between the magnet assembly and the inductor assembly 3. The magnet assembly rotates synchronously with the inductor assembly 3 via the flexible connector. When the inductor assembly 3 is energized, a magnetic force attracting or repelling the magnet assembly is formed between the inductor assembly 3 and the magnet assembly; the adsorption assembly 5 is mounted on the rotating shaft 01 and is used to adsorb the substrate 14.

[0058] The aforementioned electromagnetic levitation polishing head and polishing equipment, after the inductor component 3 is energized, generate a magnetic force that attracts or repels the magnet component. Since the net polishing pressure per unit area applied to the substrate 14 is determined by the gravity of the adsorption component 5 and the pressure applied by the magnet component to the adsorption component 5, and the pressure applied by the magnet component to the adsorption component 5 is determined by the gravity and magnetic force of the magnet component, the magnitude and direction of the electromagnetic force can be linearly adjusted by adjusting the magnitude and direction of the current input to the inductor component 3, thereby precisely controlling the net polishing pressure.

[0059] This application uses electromagnetic force directly as a pressure source. By controlling the current of the inductor component 3 to adjust the magnitude and direction of the magnetic force, millisecond-level response control can be achieved, replacing the traditional pneumatic pressurization method.

[0060] Meanwhile, each inductor unit 31 in this application is individually controlled by the central control system 2. The central control system 2 can adjust the current magnitude and direction of each inductor unit 31 respectively, thereby adjusting the magnitude and direction of the magnetic force in different areas of the substrate 14 and optimizing the pressure distribution in each area of ​​the substrate 14, such as performing fine independent pressure control on the four corners of the square substrate 14.

[0061] Furthermore, since the inductor assembly 3 and the magnet assembly can rotate synchronously with the rotating shaft 01, the inductor assembly 3 and the permanent magnet 41 can be kept relatively stationary, thereby eliminating magnetic resistance fluctuations in the magnetic circuit during rotation, stabilizing the net polishing pressure, and thus avoiding surface vibration marks and scratches. The partition control of the substrate 14 and the synchronous rotation design of this application improve the overall polishing quality.

[0062] Therefore, this application improves the overall polishing quality while enhancing response control by directly using electromagnetic force as a pressure source.

[0063] Combination Figure 1 and Figure 2 As shown, in some embodiments, the electromagnetic levitation polishing head further includes a polishing shell 7, which is disposed on the rotating shaft 01. A first accommodating space is formed inside the polishing shell 7. The inductor assembly 3, the flexible connector, the magnet assembly, and the adsorption assembly 5 are all located in the first accommodating space. A polishing hole is provided on the polishing shell 7, which is connected to the first accommodating space. The polishing hole is used for the adsorption assembly 5 to adsorb the substrate 14 through the polishing hole.

[0064] Specifically, the upper end of the rotating shaft 01 is connected to an external drive motor to provide rotational power. The rotating shaft 01 has a hollow structure and houses the vacuum circuit, coolant lines, and electrical cables.

[0065] The electromagnetic levitation polishing head of this application is designed for a square shape for the substrate 14. Therefore, the polishing housing 7 is also square in shape. The rotating shaft 01 passes through the center of the polishing housing 7. The polishing hole is located below the polishing housing 7 and is also square in shape, and is located at the center of the bottom surface of the polishing housing 7. The substrate 14 can be adsorbed and fixed by the adsorption component 5 located in the first receiving space through the square hole.

[0066] In some embodiments, the inductor unit 31 has a ring structure, and multiple inductor units 31 are concentrically arranged around the rotating shaft O1.

[0067] Specifically, the inductor unit 31 is in the shape of a square ring. Multiple inductor units 31 are arranged in a ring around the rotating shaft 01 from the inside out. The multiple inductor units 31 can cover various areas of the substrate 14 to ensure uniform magnetic field coverage.

[0068] The central control system 2 includes multiple power channels. Each inductor unit 31 can be connected to different power channels of the central control system 2 through wires passing through the hollow shaft 01, thereby enabling the central control system 2 to independently adjust the current of each inductor unit 31, thereby adjusting the magnetic force of different areas of the substrate 14 and optimizing the pressure distribution.

[0069] The central control system 2 also includes a pressure sensor, which can detect the pressure exerted by the permanent magnet 41 on the adsorption component 5 in real time.

[0070] Combination Figure 2 and Figure 3 As shown, in some embodiments, the inductor assembly 3 further includes a second support 32 and a first yoke 33. The second support 32 is disposed on the rotating shaft 01, and the flexible connector is disposed between the magnet assembly and the second support 32. The first yoke 33 is disposed on the second support 32, and multiple inductor units 31 are wound around the first yoke 33.

[0071] Specifically, the second bracket 32 ​​is fixed on the rotating shaft 01, the inductor unit 31 is an excitation coil, the cross-sectional contours of the first iron yoke 33 and the excitation coil are both U-shaped, and the outer contour dimensions of the first iron yoke 33 match the square substrate 14 to be polished (e.g., the square substrate 14 is 510 mm × 515 mm) to ensure that the magnetic field line distribution area is highly coincident with the projected contour of the square substrate 14, so that the magnetic field strength distribution from the center of the substrate 14 to the four corners is more uniform, fundamentally improving the problem of insufficient pressure at the four corners of the circular magnetic field on the square substrate 14.

[0072] The inductor unit 31 consists of two coils: an inner coil and an outer coil. The inner coil corresponds to the central area of ​​the substrate 14, while the outer coil corresponds to the edge and four corner areas of the substrate 14. The inner and outer coils are connected to different power channels of the central control system 2 via wires passing through the hollow shaft 01. The central control system 2 can independently adjust the current of each coil.

[0073] It should be noted that this application is not limited to the number of inductor units 31, and more inductor units 31 can be added as needed.

[0074] The flexible connector is a metal bellows or diaphragm. The flexible connector is suspended below the second bracket 32. The flexible connector has the characteristics of high circumferential stiffness and low axial stiffness. The high circumferential stiffness ensures torque transmission and synchronous rotation. The low axial stiffness is to quickly adapt to the displacement of the magnet assembly in the axial direction and prevent the magnetic force change from being canceled due to excessive axial stiffness.

[0075] The magnet assembly includes a first support and a permanent magnet 41. The first support is a rigid carrier and is connected to a flexible connector. The first support is located below the second support 32, and the flexible connector is disposed between the first and second supports. The permanent magnet 41 is a neodymium iron boron magnet and is embedded or fixed on the first support. There is a working gap between the permanent magnet 41 and the first yoke 33, and the first support abuts against the adsorption assembly 5 located below it.

[0076] Multiple permanent magnets 41 are provided, and each permanent magnet 41 is arranged in a one-to-one correspondence with multiple inductor units 31. In this embodiment, each permanent magnet 41 is located directly below each inductor unit 31 corresponding to it, and the shape of each permanent magnet 41 is the same as the shape of each inductor unit 31 corresponding to it. That is, the shape of the inductor unit 31 is a square ring shape, and the shape of each permanent magnet 41 is also the same as the shape of the inductor unit 31 corresponding to it.

[0077] When the central control system 2 energizes the inductor unit 31, a magnetic force is generated between the first yoke 33 and the permanent magnet 41. By controlling the direction of the current flowing into each inductor unit 31, the direction of the magnetic force between each permanent magnet 41 and the first yoke 33 can be controlled, allowing the magnetic force to be directed towards or away from the first yoke 33. When the magnetic force is directed towards the first yoke 33, that is, the direction of the electromagnetic force is vertically upward, rapid voltage reduction can be achieved after the endpoint detection of the substrate 14.

[0078] After determining the direction of the current in each inductor unit 31, the magnitude of the magnetic force between each permanent magnet 41 and the first yoke 33 can be controlled by controlling the magnitude of the current supplied to each inductor unit 31, thereby changing the pressure of each permanent magnet on the adsorption component 5, and thus achieving the purpose of controlling the net polishing pressure. Since the pressure of the permanent magnet on the adsorption component 5 is directly applied by electromagnetic force, its response speed is much faster than that of the traditional pneumatic solution, which can meet the requirements of rapid pressure reduction and real-time dynamic adjustment after endpoint detection, and the control accuracy is greatly improved. The electromagnetic force and current have a good linear relationship in the unsaturated range, with no hysteresis phenomenon.

[0079] Combination Figure 3 As shown, in some embodiments, the electromagnetic levitation polishing head includes a limiting member 6, which is disposed on the side of the inductor assembly 3 facing the magnet assembly.

[0080] Specifically, the limiting member 6 is set on the side of the second bracket 32 ​​facing the magnet assembly. Under normal conditions, there is a gap between the limiting member 6 and the permanent magnet 41, and the magnetic force is less than the weight of the permanent magnet 41. Even if the direction of the magnetic force is vertically upward, the permanent magnet 41 will always press on the first bracket or the support plate 53 disclosed later.

[0081] If the current runs out of control, the magnetic force may exceed the weight of the permanent magnet 41. If the direction of the magnetic force is vertically upward, it may pull the permanent magnet 41 up under the influence of the magnetic force.

[0082] The limiting member 6 is designed to block the permanent magnet 41, preventing the out-of-control permanent magnet 41 from rigidly colliding with the first iron yoke 33. The limiting member 6 provides safety redundancy protection.

[0083] Combination Figure 2 and Figure 3 As shown, in some embodiments, the adsorption assembly 5 includes an adsorption element 51, an adsorption tube, and a vacuum pump. The adsorption element 51 is disposed on the rotating shaft 01, and an adsorption cavity is formed inside the adsorption element 51. A first adsorption hole 511 is provided on the adsorption element 51, which communicates with the adsorption cavity and is used to adsorb the substrate 14. One end of the adsorption tube is connected to the adsorption cavity, and the vacuum pump is connected to the other end of the adsorption tube.

[0084] Specifically, the adsorption element 51 is set on the rotating shaft 01, and the first adsorption hole 511 is opened below the adsorption element 51. When the vacuum pump is turned on, a vacuum can be drawn into the adsorption chamber, and the cover plate is attached to the lower surface of the adsorption element 51. The cover plate can be adsorbed onto the adsorption element 51 through the first adsorption hole 511.

[0085] Furthermore, multiple first adsorption holes 511 are provided, and the multiple first adsorption holes 511 are distributed in a combination of X-shape and square shape, that is, the outer edge is square, and the inside of the square is X-shaped, and the intersection of the X-shapes is located at the center of the lower surface of the adsorption member 51.

[0086] This distribution helps to distribute the adsorption force along the diagonal of the substrate 14 and ensures the reliability of adsorption at the edge of the substrate 14.

[0087] Furthermore, the adsorption assembly 5 also includes a support plate 53, which is disposed between the first support and the adsorption member 51. The support plate 53 can transmit pressure to the adsorption member 51 by bearing the downward pressure of the permanent magnet 41, and finally to the substrate 14.

[0088] Combination Figure 2 and Figure 3 As shown, in some embodiments, the adsorption component 5 includes an elastic element 52, which is disposed on the adsorption component 51. The elastic element 52 is provided with a second adsorption hole 521, which communicates with the first adsorption hole 511.

[0089] Specifically, the elastic element 52 is a flexible polished film, which is a wear-resistant polymer with a certain degree of elasticity. The elastic element 52 can buffer the substrate 14 and adapt to the shape of the substrate 14. If the surface of the substrate 14 is slightly warped, the elastic element 52 can adapt to the shape of the substrate 14 by making a small deformation based on its own elasticity.

[0090] Multiple second adsorption pores 521 are provided, and the number and distribution of the multiple second adsorption pores 521 correspond to the first adsorption pores 511.

[0091] During operation, a vacuum is drawn inside the adsorption chamber, and the atmospheric pressure difference is applied to the substrate 14 through the first adsorption hole 511 and the second adsorption hole 521, causing it to be tightly adsorbed onto the elastic member 52. In addition, positive pressure gas can be selectively introduced into the adsorption chamber as back pressure, which, in conjunction with the slight deformation of the elastic member 52, can accommodate local warping of the surface of the substrate 14.

[0092] Combination Figure 3 and Figure 4 As shown, Figure 4 A perspective view of an electromagnetic levitation polishing head according to an embodiment of this application is shown from a bottom view.

[0093] In some embodiments, the electromagnetic levitation polishing head further includes a retainer 8 disposed on the polishing housing 7 around the polishing hole, and the retainer 8 is provided with a groove 81 for guiding flow.

[0094] Specifically, the retainer 8 is disposed on the lower surface of the polishing housing 7, and it is disposed around the four periphery of the lower surface of the polishing housing 7 around the polishing hole. The retainer 8 is generally square-ring shaped.

[0095] The thickness of the retainer 8 ensures that the lower surface of the substrate 14 can be exposed from the lower surface of the retainer 8 after the substrate 14 is adsorbed onto the elastic member 52. The retaining ring can prevent the substrate 14 from sliding laterally during the high-speed rotation of the rotating shaft 01.

[0096] Multiple grooves 81 are provided on the retainer 8, and the multiple grooves 81 are spaced apart on the retainer 8. The grooves 81 are connected to the axial space where the polishing hole is located. The grooves 81 are used for guiding flow so that the polishing liquid can contact the substrate 14 located inside through the grooves 81, and the polishing waste liquid can be discharged through the grooves 81.

[0097] Furthermore, the electromagnetic levitation polishing head also includes an adjustment component 9, which is L-shaped, and four adjustment components 9 are respectively set on the four corners of the inner wall of the polishing shell 7.

[0098] The inner surface of the adjusting component 9 is provided with a buffer layer, which is made of a soft buffer material such as rubber or soft polymer. When the substrate 14 experiences a slight horizontal shift or vibration during levitation, the buffer layer can preferentially contact the corners of the substrate 14 to prevent rigid collisions from causing fragments. Since the polished housing 7 is mounted on the rotating shaft 01 and can rotate with the rotating shaft 01, it ensures that it rotates synchronously with the inductor assembly 3 and the magnet assembly, thus protecting the corners without disrupting the overall magnetic levitation pressure field.

[0099] When the electromagnetic levitation polishing head is in operation, the drive motor first lowers the rotating shaft 01. At this time, the inductor unit 31 has not yet been supplied with a large current, and the magnet assembly is suspended below the flexible connector by its own gravity. The rotating shaft 01 continues to descend until the lower surface of the substrate 14 just contacts the polishing surface to be disclosed later, at which point the rotating shaft 01 stops descending. At this time, the working air gap between the first yoke 33 and the permanent magnet 41 is at its maximum (e.g., 3.5 mm).

[0100] Subsequently, the central control system 2 supplies a preset current to the inductor unit 31. As the first yoke 33 and the inductor unit 31 rotate with the main shaft, the permanent magnet 41 also rotates with the shaft 01. The inductor assembly 3 and the magnet assembly remain relatively stationary, directly generating a stable axial magnetic force. The central control system 2 can adjust the magnitude and direction of the current supplied to each electromagnetic unit in real time according to the pressure signal uploaded by the pressure sensor, ensuring that the net polishing pressure can be accurately applied to the substrate 14, and that mechanical vibration is isolated by the flexible connector.

[0101] Next, the synchronous rotary polishing stage begins. The drive motor accelerates the rotating shaft 01 to the speed set by the process. The rotational torque is transmitted sequentially through the rotating shaft 01, the inductor assembly 3, the flexible connector, the magnet assembly, and the adsorption assembly 5, ultimately reaching the substrate 14. Because the first yoke 33 and the inductor unit 31 rotate in strict synchronization with the permanent magnet 41 below and the substrate 14, the magnetic resistance in the magnetic circuit remains constant, and there are no magnetic fluctuations caused by changes in the rotation angle, thus ensuring that the pressure on the substrate 14 under high-speed rotation remains constant. At the same time, the polishing disc 10, which will be disclosed later, drives the polishing pad 13 to rotate in the opposite direction. Combined with the radial oscillation of the electromagnetic levitation polishing head on the surface of the polishing pad 13, the substrate 14 is thoroughly polished.

[0102] To further improve the polishing quality, if an abnormality in the local flatness of the substrate 14 surface is detected during the polishing process (such as a central collapse), the central control system 2 can perform fine-tuning of the zones: on the one hand, it independently adjusts the direction of the current magnitude of the inner and outer coils, and uses the characteristics of the square magnetic circuit to correct the local pressure distribution; on the other hand, it adjusts the air pressure in the adsorption cavity, and uses the micro-deformation of the elastic element 52 to correct the local contact state of the substrate 14 without changing the total pressure.

[0103] Combination Figure 5 As shown, Figure 5 A schematic diagram of the overall structure of a polishing device according to an embodiment of this application is shown.

[0104] A polishing apparatus includes an electromagnetically levitated polishing head as described above. The polishing apparatus also includes a polishing disc 10, a dressing device 11, and a liquid supply device 12. The polishing disc 10 is provided with a polishing surface and is used to rotate around the center of the polishing surface. The polishing surface is used to polish a substrate 14. The dressing device 11 abuts against the polishing surface and is used to dress the polishing surface. The liquid supply device 12 is used to spray polishing liquid onto the polishing surface.

[0105] Specifically, the electromagnetic levitation polishing head moves horizontally above the polishing surface. The dressing device 11 is located to the side of the polishing disk 10. It drives the dressing head to swing via the dressing arm, thereby dressing and activating the polishing surface, removing residual abrasive particles and waste materials from the substrate 14, and smoothing out the deformation of the polishing surface caused by grinding. This maintains the consistency of the surface morphology of the polishing surface during polishing and stabilizes the polishing removal rate. The liquid supply device 12 distributes the polishing liquid onto the surface of the polishing surface from above.

[0106] Combination Figure 5 As shown, the polishing equipment also includes a polishing pad 13. The polishing pad 13 is detachably mounted on the polishing disc 10.

[0107] Specifically, the polishing pad 13 is also a circle with the same diameter as the polishing surface of the polishing disk 10. The polishing pad 13 and the polishing disk 10 can be detached by bonding with an adhesive layer, by mechanically clamping with a pressure ring or pressure ring on the outer periphery, or by snap-fit ​​or fitting.

[0108] In this embodiment, the polishing pad 13 and the polishing disk 10 are connected by an adhesive detachable connection, and the polishing pad 13 and the polishing disk 10 rotate together around the axis.

[0109] Polishing pad 13 is a consumable part. It can be directly replaced after wear and blockage, avoiding the wear and scratches on the pad body caused by polishing with polishing disc 10 for a long time. It also reduces the maintenance costs and time costs of re-grinding and repairing the disc.

[0110] During polishing, the electromagnetic levitation polishing head presses the substrate 14 against the surface of the polishing pad 13, while simultaneously performing rotational and radial reciprocating motions; the polishing disc 10 rotates continuously, and the liquid supply device 12 sprays polishing liquid. Under the chemical action of the polishing liquid, polishing is achieved through friction between the substrate 14 and the polishing pad 13, relying on the relative motion between the electromagnetic levitation polishing head and the polishing disc 10. During this process, the dressing device 11 is responsible for dressing and activating the surface of the polishing pad 13, removing residual abrasive particles, substrate detachment waste, and other impurities, and smoothing the surface deformation of the pad caused by abrasion, thereby maintaining the consistency of the pad surface morphology during polishing and stabilizing the polishing removal rate.

[0111] In summary, this application has the following beneficial effects:

[0112] 1. Significantly improved response speed: Direct electromagnetic force application results in a faster response speed than pneumatic solutions, meeting the requirements for rapid pressure reduction and real-time dynamic adjustment after endpoint detection, and significantly improving control accuracy. The electromagnetic force and current exhibit a good linear relationship within the unsaturated region, with no hysteresis.

[0113] 2. Perfectly adapted to square substrate 14: The square magnetic circuit makes the magnetic field distribution highly coincide with the shape of the square substrate 14. Combined with the independent control of the partitioned coils, the pressure in the center area and the four corners can be optimized separately, effectively compensating for the uneven material removal rate caused by speed differences and eliminating the over-polishing phenomenon at the edges and corners.

[0114] 3. Eliminate rotational magnetic reluctance fluctuations: The synchronous rotation structure keeps the inductor unit 31 and the permanent magnet 41 relatively stationary, ensuring constant magnetic reluctance and stable polishing pressure, thus avoiding surface ripples and scratches.

[0115] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0116] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An electromagnetic levitation polishing head, characterized in that, The electromagnetic levitation polishing head includes: Shaft; The central control system is mounted on the rotating shaft; An inductor assembly is disposed on the rotating shaft. The inductor assembly includes multiple inductor units, which are used to correspond to different areas of the substrate. Each inductor unit is electrically connected to the central control system, and the central control system is used to supply an independent control current to each inductor unit. A flexible connector is disposed on the inductor assembly; A magnet assembly is disposed on the flexible connector. There is a working gap between the magnet assembly and the inductor assembly. The magnet assembly is used to rotate synchronously with the inductor assembly through the flexible connector. When the inductor assembly is energized, a magnetic force is formed between the inductor assembly and the magnet assembly to attract or repel the magnet assembly. An adsorption component is disposed on the rotating shaft, and the magnet component abuts against the adsorption component. The adsorption component is used to adsorb the substrate.

2. The electromagnetic levitation polishing head according to claim 1, characterized in that, The magnet assembly includes: The first support is connected to the flexible connector; Multiple permanent magnets are all mounted on the first support, and each of the multiple permanent magnets corresponds to a multiple inductor unit.

3. The electromagnetic levitation polishing head according to claim 1, characterized in that, The inductor unit has a ring structure, and multiple inductor units are arranged concentrically around the rotating shaft.

4. The electromagnetic levitation polishing head according to claim 1, characterized in that, The inductor assembly includes: The second bracket is disposed on the rotating shaft, and the flexible connector is disposed between the magnet assembly and the second bracket; The first yoke is disposed on the second support, and the plurality of inductor units are wound around the first yoke.

5. The electromagnetic levitation polishing head according to claim 4, characterized in that, The first iron yoke is in the shape of a square ring.

6. The electromagnetic levitation polishing head according to claim 1, characterized in that, The adsorption component includes: An adsorption element is disposed on the rotating shaft. An adsorption cavity is formed inside the adsorption element. A first adsorption hole is provided on the adsorption element. The first adsorption hole communicates with the adsorption cavity. The adsorption hole is used to adsorb a substrate. An adsorption tube, one end of which is connected to the adsorption cavity; A vacuum pump is connected to the other end of the adsorption tube.

7. The electromagnetic levitation polishing head according to claim 6, characterized in that, The adsorption component includes an elastic element disposed on the adsorption component, and the elastic element is provided with a second adsorption hole, which communicates with the first adsorption hole.

8. The electromagnetic levitation polishing head according to claim 1, characterized in that, The electromagnetic levitation polishing head includes: A polishing housing is disposed on the rotating shaft. A first accommodating space is formed inside the polishing housing. The inductor assembly, the flexible connector, the magnet assembly, and the adsorption assembly are all located in the first accommodating space. A polishing hole is provided on the polishing housing. The polishing hole communicates with the first accommodating space. The polishing hole is used by the adsorption assembly to adsorb the substrate through the polishing hole. A retainer is disposed on the polishing housing around the polishing hole, and the retainer is provided with grooves for guiding flow.

9. A polishing device, characterized in that, The polishing equipment includes the electromagnetic levitation polishing head as described in any one of claims 1-8, and comprises: A polishing disc is provided with a polishing surface, the polishing disc is used to rotate around the center of the polishing surface, and the polishing surface is used to polish the substrate; A trimming device abuts against the polished surface; the trimming device is used to trim the polished surface. A liquid supply device is used to spray polishing liquid onto the polishing surface.

10. The polishing equipment according to claim 9, characterized in that, The polishing equipment includes: A polishing pad is detachably mounted on the polishing disc.

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