Electrochemical mechanical polishing apparatus and method

Abstract

The application relates to the technical field of semiconductor processing, in particular to an electrochemical mechanical polishing device and method, which comprises a three-axis moving mechanism, an A-axis swing unit, a C-axis rotating unit, an S-axis spindle unit, an electrochemical workstation, an upper computer and an industrial computer. The electrochemical workstation is connected with a conductive chuck and a polishing head; the upper computer is connected with the industrial computer and the electrochemical workstation. The electrochemical mechanical polishing method is adopted, the three-axis moving mechanism and the A-axis swing unit can be controlled to move by the industrial computer, the electrochemical workstation can electrify the workpiece through the conductive chuck and the polishing head, the workpiece will generate electrolysis reaction in the electrolyte stored in the liquid storage tank after being electrified, so that the machining effect of mechanical polishing is ensured, and thus the polishing machining of small-diameter hard and brittle material elements with rotary curved surface characteristics can be realized.

Description

Technical Field

[0001] This application relates to the field of semiconductor processing technology, and in particular to an electrochemical mechanical polishing apparatus and method. Background Technology

[0002] In the semiconductor field, hard and brittle materials such as silicon carbide (SiC) are widely used in high-performance devices due to their large bandgap. In the field of optical imaging, SiC has greater specific stiffness and thermal stability compared to materials such as quartz glass and beryllium. This makes silicon carbide mirrors lighter and more thermally stable while achieving the same optical aperture and precision requirements.

[0003] However, SiC single crystals possess extremely high hardness, second only to diamond and cubic boron nitride in nature. Furthermore, due to their chemical inertness, SiC single crystals react almost entirely with acid or alkaline solutions. Compared to traditional metal chemical mechanical polishing (CMP), electrochemical mechanical polishing (EMF) utilizes external circuitry to oxidize the material surface, achieving low pressure, high controllability, and excellent material removal efficiency, potentially eliminating these problems.

[0004] In related technologies, electrochemical mechanical polishing devices and methods for hard and brittle materials such as SiC and gallium nitride (GaN) have been proposed. However, these methods are limited to planarization of hard and brittle materials and cannot be used to process hard and brittle components with spherical or aspherical features (curved surface features).

[0005] Therefore, how to achieve polishing of hard and brittle material components with rotational curved surface features is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In order to achieve polishing of hard and brittle material components with the characteristics of a surface of revolution, this application provides an electrochemical mechanical polishing apparatus and method.

[0007] The electrochemical mechanical polishing apparatus and method provided in this application adopt the following technical solution: In a first aspect, an electrochemical mechanical polishing apparatus includes: Three-axis moving mechanism; A-axis swing unit, the A-axis swing unit is connected to the three-axis moving mechanism; The C-axis rotating unit is connected to the three-axis moving mechanism. The C-axis rotating unit includes a conductive chuck, and a liquid storage tank is rotatably and sealed at the lower end of the conductive chuck. The liquid storage tank stores electrolyte. The S-axis spindle unit is connected to the A-axis oscillating unit, and the S-axis spindle unit includes a polishing head; An electrochemical workstation having an anode and a cathode, the anode being connected to the conductive chuck and the cathode being connected to the polishing head; The host computer is electrically connected to the electrochemical workstation; An industrial control computer is electrically connected to the three-axis moving mechanism, the A-axis swing unit, the C-axis rotation unit, the S-axis spindle unit, and the host computer.

[0008] By adopting the above technical solution, the workpiece is fixedly mounted on the conductive chuck. The C-axis rotary unit, controlled by an industrial control computer, rotates, driving the conductive chuck and workpiece to rotate, thus achieving the main motion for mechanical polishing of the rotary surface. The S-axis spindle unit, controlled by the industrial control computer, drives the polishing head to rotate, achieving the feed motion for mechanical polishing of the rotary surface. The three-axis moving mechanism and A-axis oscillating unit, controlled by the industrial control computer, perform corresponding combined movements, allowing the polishing head on the S-axis spindle unit to perform mechanical polishing on the surface of the workpiece with a rotary surface. The rotation of the A-axis oscillating unit changes the angle of the S-axis spindle unit to adapt to the curvature changes of the workpiece's rotary surface. The electrochemical workstation can energize the workpiece through the conductive chuck and polishing head. When energized, the workpiece undergoes an electrolytic reaction in the electrolyte stored in the reservoir, ensuring the electrochemical processing effect of the mechanical polishing. This allows for the polishing of hard and brittle material components with rotary surface characteristics.

[0009] Optionally, the three-axis moving mechanism includes a base, on which a gantry is fixedly mounted. An X-axis moving unit is connected to the base below the gantry, a Y-axis moving unit is connected to the gantry, and a Z-axis moving unit is connected to the Y-axis moving unit.

[0010] By adopting the above technical solution, the X-axis moving unit is fixedly installed on the base below the gantry, the Y-axis moving unit is fixedly installed on the gantry, and the Z-axis moving unit is fixedly installed on the Y-axis moving unit. By using the fixed connection between the base and the gantry, the moving stability and operation convenience of the three-axis moving mechanism can be guaranteed.

[0011] Optionally, the A-axis swing unit is connected to the Z-axis moving unit, the C-axis rotation unit is connected to the X-axis moving unit, and the industrial computer is electrically connected to the X-axis moving unit, the Y-axis moving unit, and the Z-axis moving unit.

[0012] By adopting the above technical solution, the X-axis moving unit, Y-axis moving unit, and Z-axis moving unit can be stably controlled by the industrial control computer. The position of the C-axis rotation unit can be adjusted through the X-axis moving unit, and the height of the A-axis swing unit can be adjusted through the Z-axis moving unit. This further ensures the reliability and stability of the workpiece during the mechanical and electrochemical polishing process.

[0013] Optionally, the C-axis rotation unit includes a rotating base, on which a C-axis motor is fixedly mounted. The C-axis motor is electrically connected to an industrial control computer. A driving bevel gear is fixedly connected to the output shaft of the C-axis motor. A drive shaft is fixedly connected to the lower end of the conductive chuck. A driven gear is fixedly connected to the lower end of the drive shaft. A driven bevel gear is meshed with the outer side of the driving bevel gear. A driving gear is coaxially fixedly connected to the driven bevel gear. The driven bevel gear and the driving gear are coaxially rotatably connected to the rotating base. The driving gear meshes with the driven gear.

[0014] By adopting the above technical solution, the C-axis motor can be controlled by an industrial control computer to rotate. The C-axis motor can drive the active bevel gear and the driven bevel gear to rotate with the active gear. The active gear will drive the driven gear and the drive shaft to rotate. The drive shaft will drive the conductive chuck and the workpiece to rotate, thereby realizing the main motion of the workpiece during the electrochemical mechanical polishing process.

[0015] Optionally, the drive shaft is a hollow shaft, and the lower end face of the driven gear has a fluid flow channel communicating with the interior of the drive shaft. An impeller shaft is coaxially and fixedly connected to the lower end face of the driven gear, an impeller is fixedly connected to the outer side of the impeller shaft, and an impeller box is fixedly connected to the outer side of the impeller. The impeller box is rotatably and sealed to the lower end face of the driven gear. A drain pipe is fixedly and sealed to the side wall of the impeller box, and a spray pipe is sealed to the outer end of the drain pipe. The spray pipe sealably penetrates the side wall of the storage tank.

[0016] By adopting the above technical solution, during the electrochemical mechanical polishing process, the electrolyte flows from the gaps in the chuck into the hollow drive shaft. The electrolyte in the drive shaft enters the impeller box through the liquid flow channel. When the chuck drives the workpiece to rotate, the impeller shaft and impeller rotate synchronously with the driven gear. When the impeller rotates, it pumps the electrolyte to the drain pipe and spray pipe. The spray pipe then delivers the electrolyte to the storage tank, thereby promoting the fluidity of the electrolyte during the working process. This avoids the electrolyte from being trapped by workpiece chips during processing due to localized stagnant fluid, which would affect the electrolysis effect and ensure the stability of the electrolysis reaction, thus helping to guarantee the processing quality.

[0017] Optionally, a filter is connected between the drain pipe and the spray pipe, and a serpentine tube is connected to one end of the spray pipe that seals through the side wall of the storage tank, and a nozzle is connected to the end of the serpentine tube.

[0018] By adopting the above technical solution, the circulating electrolyte can be filtered to remove workpiece chips that are trapped in the electrolyte during processing. The filtered electrolyte can be delivered to the workpiece surface using a serpentine tube and nozzle, which can further ensure the stability of the electrolytic reaction and improve the processing quality of the workpiece.

[0019] Optionally, the conductive chuck has three centrally symmetrical jaws, and a conductive block is fixedly embedded on the working surface of the jaws. The conductive block is connected to the anode, and the conductive block is made of copper.

[0020] By adopting the above technical solution, the workpiece can be stably fixed using three centrally symmetrical jaws. Conductive blocks are fixedly embedded on the working surface of the jaws. The direct contact between the conductive blocks and the workpiece forms a conductive connection, which can increase the connection strength and reliability between the workpiece and the anode. Furthermore, the three centrally symmetrical conductive blocks can ensure the stability and balance of the electric field after the workpiece is energized. Therefore, the stability of the electrolytic reaction during the processing of the workpiece is guaranteed, thereby improving the quality of electrochemical mechanical polishing of the workpiece surface.

[0021] Optionally, the A-axis oscillation unit includes an A-axis motor electrically connected to an industrial control computer, and an oscillation frame is connected to the A-axis motor. The S-axis spindle unit includes an S-axis motor electrically connected to an industrial control computer, the S-axis motor is mounted on the oscillation frame, a conductive shaft is drivenly connected to the S-axis motor, a conductive slip ring is rotatably connected to the conductive shaft, the conductive slip ring is connected to the cathode, and the polishing head is fixedly connected to the conductive shaft.

[0022] By adopting the above technical solution, the industrial control computer controls the A-axis motor to drive the swing frame to swing, which in turn drives the S-axis spindle unit to swing smoothly. The industrial control computer controls the rotation of the S-axis motor, which in turn drives the conductive shaft to rotate. The conductive slip ring can form a conductive connection with the conductive shaft and the polishing head during the rotation of the conductive shaft, thereby ensuring a reliable connection between the cathode connection and the polishing head.

[0023] Secondly, an electrochemical mechanical polishing method includes the following steps: S1. Set the parameters of the electrochemical mechanical polishing process. The parameters of the electrochemical mechanical polishing process include the output voltage of the electrochemical workstation, the rotation speed of the C-axis rotary unit and the S-axis spindle unit, and the downward pressure of the polishing head in the Z-axis direction. S2. Calculate and evaluate the amount of material removed from the workpiece per unit time and the time required to complete the polishing of the workpiece; S3. The electrochemical workstation starts outputting voltage according to the linear change law of voltage, and the host computer detects the voltage output by the electrochemical workstation. S4. The host computer determines whether the voltage output by the electrochemical workstation meets the process conditions for electrochemical reaction, and adjusts the downward pressure of the polishing head in the Z-axis direction according to the voltage output by the electrochemical workstation. S5. After adjusting the downward pressure of the polishing head in the Z-axis direction, re-evaluate whether the voltage output by the electrochemical workstation meets the process conditions for electrochemical reaction. Repeat this cycle until the voltage output by the electrochemical workstation meets the requirements for electrochemical reaction. S6. The C-axis rotary unit and the S-axis spindle unit are controlled to rotate by the industrial control computer. The S-axis spindle unit drives the polishing head to perform mechanical polishing on the surface of the workpiece. S7. The A-axis swing unit is controlled by the industrial control computer to swing according to the curvature change of the workpiece surface, and the three-axis moving mechanism is controlled by the industrial control computer to move accordingly, so as to remove the oxides generated by the electrochemical reaction on the workpiece surface. S8. Determine whether the workpiece meets the process requirements. If it does, end the process. If it does not, continue with S1 to S8, and repeat until the workpiece meets the process requirements.

[0024] By adopting the above technical solution, the amount of material removed from the workpiece per unit time and the time required to complete the polishing of the workpiece can be calculated and evaluated. This can effectively realize the progress management of the workpiece during polishing and help ensure the efficiency of polishing the workpiece.

[0025] Specifically, step S4 includes: S41. If the voltage is greater than the predetermined value, the downward pressure of the polishing head in the Z-axis direction is reduced by the industrial control computer. S42. If the voltage is less than the predetermined value, the downward pressure of the polishing head in the Z-axis direction is increased by the industrial control computer.

[0026] By adopting the above technical solution, the height of the polishing head in the Z-axis direction can be automatically adjusted during the polishing process, thereby achieving wear compensation for the polishing head, which is beneficial to improving the electrolysis effect and ensuring the precision of the polishing process.

[0027] In summary, this application includes at least one of the following beneficial technical effects: 1. This application utilizes an industrial control computer to control the rotation of the C-axis rotary unit, which drives the conductive chuck and the workpiece to rotate, thereby achieving the main motion for mechanical polishing of the rotary surface; the industrial control computer controls the S-axis spindle unit to drive the polishing head to rotate, thereby achieving the feed motion for mechanical polishing of the rotary surface; the industrial control computer controls the three-axis moving mechanism and the A-axis swing unit to perform corresponding combined movements, which can control the polishing head on the S-axis spindle unit to perform mechanical polishing on the surface of the workpiece with the rotary surface; after the A-axis swing unit rotates, it can change the angle of the S-axis spindle unit to adapt to the curvature change of the workpiece's rotary surface; 2. This application utilizes an electrochemical workstation to energize the workpiece through a conductive chuck and polishing head. After the workpiece is energized, an electrolytic reaction occurs in the electrolyte stored in the reservoir, thereby ensuring the electrochemical processing effect of mechanical polishing. This enables the polishing of small-diameter hard and brittle material components with rotating curved surface features. 3. This application utilizes the synchronous rotation of the impeller shaft and impeller with the driven gear to pump the electrolyte to the drain pipe and spray pipe. The spray pipe then delivers the electrolyte to the storage tank, thereby promoting the fluidity of the electrolyte during operation. This prevents stagnant electrolyte from trapping workpiece chips during processing, which would affect the electrolysis effect and ensure the stability of the electrolysis reaction, thus contributing to ensuring processing quality. 4. This application utilizes three centrally symmetrical jaws to stably fix the workpiece, and a conductive block is fixedly embedded on the working surface of the jaws. The conductive block forms a conductive connection through direct contact with the workpiece, which can increase the connection strength and reliability between the workpiece and the anode. Furthermore, the three centrally symmetrical conductive blocks can ensure the stability and balance of the electric field after the workpiece is energized. Therefore, the stability of the electrolytic reaction of the workpiece during processing is guaranteed, thereby improving the quality of electrochemical mechanical polishing of the workpiece surface. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure and principle of the electrochemical mechanical polishing device in Embodiment 1 of this application.

[0029] Figure 2 This is a three-dimensional structural schematic diagram of the electrochemical mechanical polishing device in Embodiment 1 of this application.

[0030] Figure 3 This is an exploded view of the electrochemical mechanical polishing device in Embodiment 1 of this application.

[0031] Figure 4 This is a schematic diagram of the curved surface polishing of the electrochemical mechanical polishing device in Embodiment 1 of this application.

[0032] Figure 5 This is a schematic diagram of planar polishing using the electrochemical mechanical polishing apparatus in Embodiment 1 of this application.

[0033] Figure 6 This is a three-dimensional structural schematic diagram of the C-axis rotating unit of the electrochemical mechanical polishing device in Embodiment 1 of this application.

[0034] Figure 7 This is an exploded view of the C-axis rotating unit of the electrochemical mechanical polishing device in Embodiment 1 of this application.

[0035] Figure 8 This is a schematic diagram of the internal structure of the C-axis rotating unit of the electrochemical mechanical polishing device in Embodiment 1 of this application.

[0036] Figure 9 This is a flowchart of the electrochemical mechanical polishing method in Embodiment 2 of this application.

[0037] Explanation of reference numerals in the attached figures: 100. Three-axis moving mechanism; 101. Base; 102. Gantry frame; 103. X-axis moving unit; 1031. X-axis guide rail; 1032. X-axis slider; 1033. X-axis motor; 104. Y-axis moving unit; 1041. Y-axis guide rail; 1042. Y-axis slider; 1043. Y-axis motor; 105. Z-axis moving unit; 1051. Z-axis guide rail; 1052. Z-axis slider; 1053. Z-axis motor; 200. Swing unit; 201. A-axis motor; 202. Swing base; 203. Mounting base; 300. C-axis rotation unit; 301. Conductive chuck; 302. Liquid storage tank; 303. C-axis motor; 304. Driving bevel gear; 305. Drive shaft; 306. Driven gear; 307. Driven bevel gear; 308. Driving gear; 309. Liquid flow channel; 310. Impeller shaft; 311. Impeller; 312. Impeller box; 313. Drain pipe; 314. Spray pipe; 315. Filter; 316. Serpentine tube; 317. Nozzle; 318. Clamp; 319. Conductive block; 320. Rotating seat; 400. S-axis spindle unit; 401. Polishing head; 402. Conductive slip ring; 403. S-axis motor; 404. Conductive shaft; 405. Swing frame; 500. Electrochemical workstation; 501. Anode; 502. Cathode; 600. Host computer; 700. Industrial control computer; 800. Workpiece. Detailed Implementation

[0038] The following is in conjunction with the appendix Figure 1-9 This application will be described in further detail.

[0039] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "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 the present invention 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 the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0041] This application discloses an electrochemical mechanical polishing apparatus and method.

[0042] Example 1 Please refer to the above as well. Figure 1 and Figure 2 In one embodiment of this application, an electrochemical mechanical polishing device includes a base 101, a gantry 102 fixedly mounted on the base 101, an X-axis moving unit 103 connected to the base 101 below the gantry 102, a Y-axis moving unit 104 connected to the gantry 102, and a Z-axis moving unit 105 connected to the Y-axis moving unit 104. The X-axis moving unit 103, the Y-axis moving unit 104, and the Z-axis moving unit 105 form a three-axis moving mechanism 100.

[0043] It is understood that in other embodiments of this application, the three-axis moving mechanism 100 may also have an X-axis moving unit 103 on the base 101, a Z-axis moving unit 105 installed on the X-axis moving unit 103, and a Y-axis moving unit 104 installed on the Z-axis moving unit 105. This can also achieve adjustable positional movement in the X, Y, and Z axes. Therefore, the three-axis moving mechanism 100 is not limited to the specific positional settings of the X-axis moving unit 103, the Y-axis moving unit 104, and the Z-axis moving unit 105.

[0044] In this embodiment, the base 101 and the gantry 102 fixedly installed on the base 101 are preferably configured in the specific positions of the X-axis moving unit 103, Y-axis moving unit 104 and Z-axis moving unit 105. This can ensure the stability, convenience and reliability of the position adjustment of the three-axis moving mechanism 100 during operation, thereby ensuring the processing quality of polishing the workpiece 800.

[0045] Please refer to the above as well. Figure 2 and Figure 3In a specific embodiment of this application, the X-axis moving unit 103 includes an X-axis guide rail 1031 fixedly mounted on the upper surface of the base 101, an X-axis slider 1032 slidably connected to the X-axis guide rail 1031, and an X-axis motor 1033 fixedly mounted on the X-axis guide rail 1031. The X-axis motor 1033 can drive the X-axis slider 1032 to slide along the X-axis guide rail 1031. The transmission method of the X-axis motor 1033 driving the X-axis slider 1032 to slide includes, but is not limited to, belt drive, chain drive, screw drive, etc. In this embodiment, screw drive is preferred because screw drive has the advantages of simple structure, stability and reliability, which is conducive to ensuring the moving accuracy of the X-axis moving unit 103.

[0046] Please refer to the above as well. Figure 2 and Figure 3 In a specific embodiment of this application, the Y-axis moving unit 104 includes a Y-axis guide rail 1041 fixedly mounted on the gantry frame 102, a Y-axis slider 1042 slidably connected to the Y-axis guide rail 1041, and a Y-axis motor 1043 fixedly mounted on the Y-axis guide rail 1041. The Y-axis motor 1043 can drive the Y-axis slider 1042 to slide along the Y-axis guide rail 1041. The transmission method for the Y-axis motor 1043 to drive the Y-axis slider 1042 to slide includes, but is not limited to, belt drive, chain drive, screw drive, etc. In this embodiment, screw drive is preferred because screw drive has the advantages of simple structure, stability and reliability, which is beneficial to ensuring the moving accuracy of the Y-axis moving unit 104.

[0047] Please refer to the above as well. Figure 2 and Figure 3 In a specific embodiment of this application, the Z-axis moving unit 105 includes a Z-axis guide rail 1051 fixedly mounted on the upper Y-axis slider 1042, a Z-axis slider 1052 slidably connected to the Z-axis guide rail 1051, and a Z-axis motor 1053 fixedly mounted on the Z-axis guide rail 1051. The Z-axis motor 1053 can drive the Z-axis slider 1052 to slide along the Z-axis guide rail 1051. The transmission method for the Z-axis motor 1053 to drive the Z-axis slider 1052 to slide includes, but is not limited to, belt drive, chain drive, screw drive, etc. In this embodiment, screw drive is preferred because screw drive has the advantages of simple structure, stability and reliability, which is beneficial to ensuring the moving accuracy of the Z-axis moving unit 105.

[0048] Please refer to the above as well. Figure 2 and Figure 3In a specific embodiment of this application, a mounting base 203 is fixedly mounted on the Z-axis slider 1052, and an A-axis motor 201 is fixedly mounted on the mounting base 203. A swing seat 202 is rotatably connected inside the mounting base 203. The mounting base 203, the A-axis motor 201, and the swing seat 202 combine to form an A-axis swing unit 200. The A-axis motor 201 can drive the swing seat 202 to swing. The transmission form for the A-axis motor 201 to drive the swing seat 202 to swing can be a gear transmission or a worm gear transmission. In this embodiment, a worm gear transmission is preferred because the structure of the worm gear transmission is relatively compact and has advantages such as a large transmission ratio, large load capacity, smooth and quiet operation, self-locking performance, and self-aligning performance, which can ensure stability during use.

[0049] Please refer to the above as well. Figure 2 and Figure 3 In a specific embodiment of this application, a swing frame 405 is fixedly mounted on the swing base 202, an S-axis motor 403 is fixedly mounted on the swing frame 405, a conductive shaft 404 is coaxially fixedly connected to the S-axis motor 403, a polishing head 401 is fixedly connected to the end of the conductive shaft 404 away from the S-axis motor 403, and a conductive slip ring 402 is rotatably connected to the conductive shaft 404. The polishing head 401, the conductive slip ring 402, the S-axis motor 403, the conductive shaft 404, and the swing frame 405 are combined to form an S-axis spindle unit 400.

[0050] Please refer to the above as well. Figure 3 , Figure 6 and Figure 7 In a specific embodiment of this application, a rotating seat 320 is fixedly installed on the X-axis slider 1032, and a C-axis motor 303 is fixedly installed on the rotating seat 320. A driving bevel gear 304 is fixedly connected to the output shaft of the C-axis motor 303. A driven bevel gear 307 meshes with the driving bevel gear 304 on its outer side. A driving gear 308 is fixedly connected to the driven bevel gear 307 on its coaxial axis. A driven gear 306 meshes with the driving gear 308 on its outer side. A drive shaft 305 is fixedly connected to the upper end face of the driven gear 306 on its coaxial axis. A conductive chuck 301 is detachably installed on the drive shaft 305. The rotating base 320, C-axis motor 303, driving bevel gear 304, driven bevel gear 307, driving gear 308, driven gear 306, drive shaft 305, and conductive chuck 301 are combined to form the C-axis rotating unit 300. The conductive chuck 301 can clamp and fix the workpiece 800, and the C-axis motor 303 can drive the conductive chuck 301 and the workpiece 800 to rotate, thereby realizing the main motion of the workpiece 800 in the mechanical polishing process.

[0051] Please refer to the above as well. Figure 7 and Figure 8In a specific embodiment of this application, a liquid storage tank 302 is rotatably and sealed to the outside of the drive shaft 305. The liquid storage tank 302 is fixedly installed on the rotating seat 320. The liquid storage tank 302 stores electrolyte. The drive shaft 305 is a hollow shaft. A liquid flow channel 309 communicating with the inside of the drive shaft 305 is opened on the lower end face of the driven gear 306. An impeller shaft 310 is coaxially and fixedly connected to the lower end face of the driven gear 306. An impeller 311 is fixedly connected to the outside of the impeller shaft 310. An impeller box 312 is fixedly connected to the outside of the impeller 311. The impeller box 312 is rotatably and sealed to the lower end face of the driven gear 306. A drain pipe 313 is sealed and fixedly connected to the side wall of the impeller box 312. A spray pipe 314 is sealed and connected to the outer end of the drain pipe 313. The spray pipe 314 sealably penetrates the side wall of the liquid storage tank 302.

[0052] Please refer to the above as well. Figure 7 and Figure 8 In a specific embodiment of this application, a filter 315 is connected between the drain pipe 313 and the spray pipe 314. A serpentine tube 316 is connected to one end of the spray pipe 314 that seals and penetrates the side wall of the storage tank 302. A nozzle 317 is connected to the end of the serpentine tube 316. The filter 315 filters the circulating electrolyte, removing chips from the workpiece 800 that may be trapped in the electrolyte during processing. The serpentine tube 316 and nozzle 317 then deliver the filtered electrolyte to the processing surface of the workpiece 800, further ensuring the stability of the electrolytic reaction and improving the processing quality of the workpiece 800.

[0053] Please refer to the above as well. Figure 1 and Figure 2In the specific embodiments of this application, the conductive chuck 301 can be a three-jaw chuck or a four-jaw chuck in the prior art. In this embodiment, a three-jaw chuck is preferred because it not only has the characteristics of high efficiency and can be easily and quickly clamped and disassembled, but also has the ability to self-center, which is conducive to ensuring processing quality and processing accuracy. The three-jaw chuck has three centrally symmetrical jaws 318. In this embodiment, based on the existing three-jaw chuck, a conductive block 319 is fixedly embedded on the working surface of the jaws 318. The conductive block 319 is made of copper. An electrochemical workstation 500 is electrically connected between the conductive block 319 and the conductive slip ring 402. The electrochemical workstation 500 has an anode 501 and a cathode 502. The anode 501 of the electrochemical workstation 500 is connected to the conductive block 319, and the cathode 502 of the electrochemical workstation 500 is connected to the conductive slip ring 402. In this way, during the operation, the electrochemical workstation 500 can output voltage to the workpiece 800 according to the linear voltage change law through the conductive block 319 and the conductive slip ring 402. After the workpiece 800 is energized, an electrolytic reaction will occur in the electrolyte stored in the storage tank 302, thereby ensuring the electrochemical processing effect of mechanical polishing. In this way, electrochemical mechanical polishing processing of the workpiece 800 can be realized.

[0054] It is understandable that the conductive block 319 is made of copper, because copper not only has good conductivity, but is also softer than other metals. The conductive block 319 made of copper can not only ensure the connection strength and reliability between the workpiece 800 and the anode 501 during operation, but also avoid scratching the surface of the workpiece 800 when clamping it.

[0055] Please refer to the above as well. Figure 1 and Figure 2 In one embodiment of this application, an electrochemical mechanical polishing device further includes a host computer 600 and an industrial control computer 700. The host computer 600 is electrically connected to an electrochemical workstation 500 to detect the voltage and current characteristics of the electrochemical workstation 500. The host computer 600 is electrically connected to the industrial control computer 700, which is also electrically connected to X-axis motor 1033, Y-axis motor 1043, Z-axis motor 1053, A-axis motor 201, C-axis motor 303, and S-axis motor 403. By detecting the voltage and current characteristics of the electrochemical workstation 500, the host computer 600 can control the industrial control computer 700 to adjust the process conditions.

[0056] The implementation principle of the electrochemical mechanical polishing device in this application embodiment is as follows: When clamping workpiece 800, the industrial control computer 700 controls the Y-axis moving unit 104 to drive the S-axis spindle unit 400 to move outside the liquid storage tank 302, install workpiece 800 in the conductive chuck 301, and lock the conductive chuck 301 to complete the clamping of workpiece 800.

[0057] When performing electrochemical mechanical polishing on workpiece 800, please refer to the following: Figure 4 and Figure 5 The industrial control computer 700 controls the C-axis rotation unit 300 to rotate, which in turn drives the conductive chuck 301 and the workpiece 800 to rotate. Then, the industrial control computer 700 controls the S-axis spindle unit 400 to rotate the polishing head 401. Simultaneously, the industrial control computer 700 controls the three-axis moving mechanism 100 and the A-axis swing unit 200 to perform corresponding combined movements, thereby controlling the polishing head 401 on the S-axis spindle unit 400 to perform mechanical polishing on the surface of the workpiece 800, which has a surface of rotation. Figure 4 As shown, when the C-axis rotation unit 300 drives the conductive chuck 301 and the workpiece 800 to rotate, the A-axis swing unit 200 controls the S-axis spindle unit 400 to swing. Combined with the linkage of the Y-axis movement unit 104 and the Z-axis movement unit 105, polishing of the workpiece 800 with a curvature variation on a surface of revolution can be achieved. Figure 5 As shown, when the C-axis rotation unit 300 drives the conductive chuck 301 and the workpiece 800 to rotate, the S-axis spindle unit 400 is translated by the Y-axis moving unit 104, so that the workpiece 800 with a flat surface can be polished.

[0058] During mechanical polishing, the conductive slip ring 402 transmits the current output from the electrochemical workstation 500 to the polishing head 401, which acts as the cathode in the electrochemical mechanical polishing process. The conductive chuck 301 transmits the current output from the electrochemical workstation 500 to the workpiece 800, which becomes the anode after being energized. When the electrolyte inside the storage tank 302 is energized, a chemical reaction occurs simultaneously at the anode and cathode. After the workpiece 800 loses electrons, oxides with significantly reduced hardness are formed on the surface, resulting in passivation and a halt to the reaction. At this point, the oxides are rapidly removed by the rotation of the polishing head after contacting the component surface, thus obtaining a smooth and clean surface. This enables electrochemical mechanical polishing of small-diameter, hard, and brittle material components with features of a curved surface of revolution.

[0059] When disassembling workpiece 800, after the electrochemical mechanical polishing process is completed, the industrial control computer 700 controls the Y-axis moving unit 104 to drive the S-axis spindle unit 400 to move outside the liquid storage tank 302. After releasing the conductive chuck 301, the workpiece 800 is taken out from the conductive chuck 301, thus completing the disassembly of workpiece 800.

[0060] Example 2 Please refer to the above. Figure 1 and Figure 9 In one embodiment of this application, an electrochemical mechanical polishing method includes the following steps: S1. Set the parameters of the electrochemical mechanical polishing process. The parameters of the electrochemical mechanical polishing process include the output voltage of the electrochemical workstation 500, the rotation speed of the C-axis rotary unit 300 and the S-axis spindle unit 400, and the downward pressure of the polishing head 401 in the Z-axis direction. S2. Calculate and evaluate the amount of material removed from workpiece 800 per unit time and the time required to complete the polishing of workpiece 800; S3. Electrochemical workstation 500 starts outputting voltage according to the linear change law of voltage, and host computer 600 detects the voltage output by electrochemical workstation 500. S4. The host computer 600 determines whether the voltage output by the electrochemical workstation 500 meets the process conditions for electrochemical reaction, and adjusts the downward pressure of the polishing head 401 in the Z-axis direction according to the voltage output by the electrochemical workstation 500. S41. If the voltage is greater than the predetermined value, the downward pressure of the polishing head 401 in the Z-axis direction is reduced by the industrial control computer 700. S42. If the voltage is less than the predetermined value, the pressure of the polishing head 401 in the Z-axis direction is increased by the industrial control computer 700.

[0061] S5. After adjusting the downward pressure of the polishing head 401 in the Z-axis direction, re-determine whether the voltage output by the electrochemical workstation 500 meets the process conditions for electrochemical reaction. Repeat this process until the voltage output by the electrochemical workstation 500 meets the requirements for electrochemical reaction. S6. The C-axis rotation unit 300 and the S-axis spindle unit 400 are controlled to rotate by the industrial control computer 700. The S-axis spindle unit 400 drives the polishing head 401 to perform mechanical polishing on the surface of the workpiece 800. S7. The A-axis swing unit 200 is controlled by the industrial control computer 700 to swing according to the curvature change of the workpiece 800 surface, and the three-axis moving mechanism 100 is controlled by the industrial control computer 700 to move accordingly, so as to remove the oxides generated by the electrochemical reaction on the surface of the workpiece 800. S8. Determine whether workpiece 800 meets the process requirements. If it does, end the process. If it does not, continue with S1 to S8 and repeat until workpiece 800 meets the process requirements.

[0062] This embodiment, by employing the above method, ensures the processing quality of the workpiece by detecting whether it meets the predetermined process requirements, avoiding incorrect processing and thus preventing wasted processing costs. Calculating and evaluating the amount of material removed from the workpiece per unit time and the time required to complete polishing effectively manages the progress of the polishing process, thus ensuring the efficiency of polishing.

[0063] Furthermore, by automatically adjusting the height of the polishing head 401 in the Z-axis direction during the polishing process, wear compensation for the polishing head 401 can be achieved, which is beneficial to improving the electrolysis effect and ensuring the precision of the polishing process.

[0064] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An electrochemical mechanical polishing apparatus, characterized in that, include: Three-axis moving mechanism (100); A-axis swing unit (200), the A-axis swing unit (200) is connected to the three-axis moving mechanism (100); C-axis rotation unit (300), the C-axis rotation unit (300) is connected to the three-axis moving mechanism (100), the C-axis rotation unit (300) includes a conductive chuck (301), the lower end of the conductive chuck (301) is rotatably connected to a liquid storage tank (302), the liquid storage tank (302) stores electrolyte inside; S-axis spindle unit (400), which is connected to the A-axis swing unit (200), includes a polishing head (401). An electrochemical workstation (500) has an anode (501) and a cathode (502), the anode (501) being connected to the conductive chuck (301) and the cathode (502) being connected to the polishing head (401); A host computer (600) is electrically connected to the electrochemical workstation (500); An industrial computer (700) is electrically connected to the three-axis moving mechanism (100), the A-axis swing unit (200), the C-axis rotation unit (300), the S-axis spindle unit (400), and the host computer (600). The three-axis moving mechanism (100) includes a base (101), on which a gantry (102) is fixedly mounted. An X-axis moving unit (103) is connected to the base (101) below the gantry (102). A Y-axis moving unit (104) is connected to the gantry (102), and a Z-axis moving unit (105) is connected to the Y-axis moving unit (104). An A-axis swing unit (200) is connected to the Z-axis moving unit (105), and a C-axis rotation unit (300) is connected to the X-axis moving unit (103). The industrial computer (700) is electrically connected to the X-axis moving unit (103), Y-axis moving unit (104), and Z-axis moving unit (105); the C-axis rotating unit (300) includes a rotating base (320), on which a C-axis motor (303) is fixedly mounted. The C-axis motor (303) is electrically connected to the industrial computer (700), and a drive bevel gear (304) is fixedly connected to the output shaft of the C-axis motor (303). A drive shaft (305) is fixedly connected to the lower end of the conductive chuck (301), and a drive shaft (305) is fixedly connected to the lower end of the drive shaft (305). Driven gear (306), the outer side of the driving bevel gear (304) is meshed with driven bevel gear (307), driven bevel gear (307) is provided with driving gear (308) coaxially fixedly connected to it, driven bevel gear (307) and driving gear (308) are coaxially rotatably connected to the rotating seat (320), driving gear (308) meshes with driven gear (306); the drive shaft (305) is a hollow shaft, the lower end face of driven gear (306) is provided with a fluid flow channel (309) communicating with the interior of drive shaft (305). The driven gear (306) is coaxially fixedly connected to the lower end face of the driven gear (306), and the impeller (311) is fixedly connected to the outer side of the impeller shaft (310). The impeller box (312) is fixedly connected to the outer side of the impeller (311). The impeller box (312) is sealed and rotatably connected to the lower end face of the driven gear (306). The side wall of the impeller box (312) is sealed and fixedly connected to the drain pipe (313). The outer end of the drain pipe (313) is sealed and connected to the spray pipe (314). The spray pipe (314) sealably penetrates the side wall of the storage tank (302).

2. The electrochemical mechanical polishing apparatus according to claim 1, characterized in that: A filter (315) is connected between the drain pipe (313) and the spray pipe (314). One end of the spray pipe (314) that is sealed through the side wall of the storage tank (302) is connected to a serpentine tube (316), and the end of the serpentine tube (316) is connected to a nozzle (317).

3. The electrochemical mechanical polishing apparatus according to claim 1, characterized in that: The conductive chuck (301) has three centrally symmetrical jaws (318). A conductive block (319) is fixedly embedded on the working surface of the jaw (318). The conductive block (319) is connected to the anode (501). The conductive block (319) is made of copper.

4. The electrochemical mechanical polishing apparatus according to claim 1, characterized in that: The A-axis swing unit (200) includes an A-axis motor (201) electrically connected to an industrial computer (700), and a swing frame (405) is connected to the A-axis motor (201). The S-axis spindle unit (400) includes an S-axis motor (403) electrically connected to an industrial computer (700), and the S-axis motor (403) is mounted on the swing frame (405). A conductive shaft (404) is drivenly connected to the S-axis motor (403), and a conductive slip ring (402) is rotatably connected to the conductive shaft (404). The conductive slip ring (402) is connected to the cathode (502), and the polishing head (401) is fixedly connected to the conductive shaft (404).

5. An electrochemical mechanical polishing method, comprising the following steps: S1. Set the parameters of the electrochemical mechanical polishing process. The parameters of the electrochemical mechanical polishing process include the output voltage of the electrochemical workstation (500), the rotation speed of the C-axis rotary unit (300) and the S-axis spindle unit (400), and the downward pressure of the polishing head (401) in the Z-axis direction. S2. Calculate and evaluate the amount of material removed from the workpiece (800) per unit time and the time required to complete the polishing of the workpiece (800); S3. The electrochemical workstation (500) starts to output voltage according to the linear change law of voltage, and the host computer (600) detects the voltage output by the electrochemical workstation (500). S4. The host computer (600) determines whether the voltage output by the electrochemical workstation (500) meets the process conditions for electrochemical reaction, and adjusts the downward pressure of the polishing head (401) in the Z-axis direction according to the voltage output by the electrochemical workstation (500). S5. After adjusting the downward pressure of the polishing head (401) in the Z-axis direction, re-determine whether the voltage output by the electrochemical workstation (500) meets the process conditions for electrochemical reaction. Repeat this cycle until the voltage output by the electrochemical workstation (500) meets the requirements for electrochemical reaction. S6. The C-axis rotation unit (300) and the S-axis spindle unit (400) are controlled to rotate by the industrial control computer (700). The S-axis spindle unit (400) drives the polishing head (401) to perform mechanical polishing on the surface of the workpiece (800). S7. The A-axis swing unit (200) is controlled by the industrial control computer (700) to swing according to the curvature change of the workpiece (800) surface, and the three-axis moving mechanism (100) is controlled by the industrial control computer (700) to move accordingly, so as to remove the oxides generated by the electrochemical reaction on the surface of the workpiece (800). S8. Determine whether the workpiece (800) meets the process requirements. If it does, end the process. If it does not, continue with S1 to S8 and repeat until the workpiece (800) meets the process requirements.

6. The electrochemical mechanical polishing method according to claim 5, characterized in that, Step S4 includes: S41. If the voltage is greater than the predetermined value, the pressure of the polishing head (401) in the Z-axis direction is reduced by the industrial control computer (700). S42. If the voltage is less than the predetermined value, the pressure of the polishing head (401) in the Z-axis direction is increased by the industrial control computer (700).

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