Electromagnetic vibration cavitation assisted chemical mechanical polishing device and method

Abstract

The invention provides an electromagnetic vibration cavitation assisted chemical mechanical polishing device and method.The device comprises a polishing disc, a mounting frame, a polishing main shaft and a mounting disc, the polishing main shaft is mounted on the mounting frame and comprises a connecting shaft, a hollow rotating shaft, a stator sleeve and a vertical floating mechanism, and the vertical floating mechanism is connected between the connecting shaft and the hollow rotating shaft; the vertical floating mechanism vibrates in a reciprocating mode in the vertical direction while driving the hollow rotating shaft to rotate, a liquid inlet used for introducing polishing liquid is formed in the outer side of the stator sleeve, the mounting disc is connected to the bottom of the hollow rotating shaft, a workpiece is clamped by the bottom of the mounting disc, and the lower surface of the workpiece is evenly coated with an agent injected through the liquid inlet. Polishing liquid enters the position between the workpiece and the polishing disc to form a liquid film, and when the mounting disc and the polishing disc rotate relatively, the polishing uniformity of the workpiece can be improved. And by arranging the vertical floating mechanism, the workpiece can axially vibrate relative to the polishing disc while the mounting disc and the polishing disc rotate relatively, and the polishing efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polishing, and in particular to a chemical mechanical polishing device and method assisted by electromagnetic vibration cavitation. Background Art

[0002] With the continuous development of semiconductor technology, the application of hard and brittle materials in electronic devices, optoelectronic equipment and other high-precision mechanical equipment has gradually increased. Especially in the manufacture of integrated circuits, the surface quality of semiconductor materials (such as silicon, sapphire, gallium nitride, diamond, etc.) has an increasingly significant impact on device performance. Surface quality is not only directly related to the packaging, heat dissipation and stability of the chip, but also plays a decisive role in the yield rate and service life of the product. Therefore, higher requirements are placed on the surface polishing process of these hard and brittle materials. As a commonly used semiconductor material polishing technology, traditional polishing has been widely used in the surface treatment of wafers, but it still has certain limitations. Due to the hard and brittle characteristics of semiconductor materials, traditional polishing processes are prone to poor polishing uniformity, severe surface or subsurface damage, and low efficiency. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, the embodiment of the present invention provides an electromagnetic vibration cavitation assisted chemical mechanical polishing device and method, which can improve the uniformity and polishing efficiency of polishing.

[0004] In one aspect, an embodiment of the present invention proposes a chemical mechanical polishing device assisted by electromagnetic vibration cavitation, comprising: a polishing disc, a mounting frame, a polishing spindle and a mounting disc, wherein the mounting frame is arranged above the polishing disc, and a spindle servo motor is installed on the mounting frame, wherein the output shaft of the spindle servo motor is vertically downward, and the rotation direction of the output shaft of the spindle servo motor is opposite to the rotation direction of the polishing disc.

[0005] The polishing spindle is installed on the mounting frame, and the spindle servo motor is connected to and drives the polishing spindle to rotate along the z-axis. The polishing spindle includes a connecting shaft, a hollow rotating shaft, a stator sleeve and a vertical floating mechanism. The connecting shaft and the output shaft of the spindle servo motor are connected by a coupling, and the vertical floating mechanism is connected between the connecting shaft and the hollow rotating shaft. The vertical floating mechanism is suitable for driving the hollow rotating shaft to reciprocate and vibrate in the vertical direction while rotating along the z-axis. The stator sleeve is sleeved on the outer periphery of the hollow rotating shaft, and the stator sleeve and the hollow rotating shaft are rotationally connected by the rotor sleeve. The interior of the hollow rotating shaft has a vertical through hole along the axial direction, and the outer side of the stator sleeve is provided with a liquid inlet for introducing polishing liquid, and the rotor sleeve and the hollow rotating shaft are respectively provided with channels to connect the liquid inlet with the vertical through hole of the hollow rotating shaft.

[0006] The mounting plate is detachably connected to the bottom of the hollow rotating shaft, a mounting groove for clamping the workpiece is provided at the bottom of the mounting plate, a liquid outlet is provided at the center of the mounting plate, and the liquid outlet is connected to the vertical through hole so that the agent injected from the liquid inlet can be evenly coated on the lower surface of the workpiece, and the lower surface of the workpiece is suitable for contacting with the upper surface of the polishing plate for polishing.

[0007] In some embodiments, the chemical mechanical polishing device also includes a guide rail module, which includes a column, an x-axis guide rail and a y-axis guide rail. The y-axis guide rail is arranged in a horizontal direction, and a slider is horizontally slidably connected to the y-axis guide rail. The mounting frame is fixedly connected to the slider. The slider moves horizontally along the y-axis guide rail, driving the mounting frame to move synchronously. The column is provided with two columns and is respectively fixedly connected to the bottom of the two ends of the y-axis guide rail. The bottom of each column is respectively connected to an x-axis guide rail. The two x-axis guide rails are respectively arranged on both sides of the polishing disk. The x-axis guide rail is arranged in a horizontal direction, and a foot seat is horizontally slidably connected to the x-axis guide rail. The bottom of the column is fixedly connected to the foot seat. The two foot seats move horizontally synchronously along the x-axis guide rail, driving the column and the y-axis guide rail to move synchronously.

[0008] In some embodiments, the mounting frame includes a C-shaped frame, a guide rod and a slotted chuck, the C-shaped frame includes an upper end plate, a back plate and a lower end plate, the upper end plate and the lower end plate are arranged in parallel, the back plate is fixedly connected between the upper end plate and the lower end plate to form a C-shaped structure, the housing of the spindle servo motor is installed on the upper end plate, the output shaft of the spindle servo motor vertically penetrates the upper end plate downward, the lower end plate is provided with an opening for the polishing spindle to pass through, a plurality of guide rods are evenly distributed, the slotted chuck is fixedly connected to the bottom of the lower end plate through the guide rods, each guide rod is respectively slidably connected with a linear bearing, the stator sleeve is fixedly connected to the non-rotating guide plate, all guide rods penetrate the non-rotating guide plate in the vertical direction, and the non-rotating guide plate is respectively fixedly connected to all linear bearings at the guide rod penetration point, so that the non-rotating guide plate slides along the axial direction of the guide rod, and the slotted chuck is provided with a C-shaped opening from the center to the edge, so that the stator sleeve is clamped into the slotted chuck and slides synchronously with the non-rotating guide plate in the vertical direction.

[0009] In some embodiments, an electric slip ring is sleeved on the connecting shaft, an electric slip ring fixing plate is fixedly connected to the lower side of the upper end plate via a screw and a nut, and the outer side of the electric slip ring is mounted on the electric slip ring fixing plate.

[0010] In some embodiments, the vertical floating mechanism includes an upper fixed disk, a lower fixed disk, a floating disk, an optical axis, an iron core, a coil and a permanent magnet. Several optical axes are evenly distributed around the edge of the upper fixed disk and connected between the upper fixed disk and the lower fixed disk. The upper fixed disk is fixedly connected to the bottom of the connecting shaft, the iron core is fixedly connected to the center of the upper fixed disk, the coil is wound around the outside of the iron core, and the floating disk is arranged between the upper fixed disk and the lower fixed disk. All optical axes pass through the edge of the floating disk, and each optical axis is sleeved with an upper spring and a lower spring. The upper spring is connected between the floating disk and the upper fixed disk, and the lower spring is connected between the floating disk and the lower fixed disk. The floating disk floats up and down along the axial direction of the optical axis. The upper end of the floating disk is fixedly connected to the permanent magnet, the iron core is located directly above the permanent magnet, and the floating disk is fixedly connected to the hollow rotating shaft. When high-frequency alternating current is passed through the coil, the iron core and the coil generate an alternating force of attraction and repulsion on the permanent magnet, driving the floating disk to float up and down along the optical axis, thereby driving the mounting disk and the workpiece to vibrate up and down while rotating on the polishing disk.

[0011] In some embodiments, a fixed sleeve, a transition sleeve and a tensioning sleeve are connected between the floating disk and the hollow rotating shaft. The fixed sleeve, the transition sleeve and the tensioning sleeve are connected in sequence from top to bottom. The fixed sleeve is coaxially fixedly connected to the bottom of the center of the floating disk, the transition sleeve is coaxially fixedly connected to the bottom of the fixed sleeve, the transition sleeve and the hollow rotating shaft are fixedly connected to the end cover, the tensioning sleeve is coaxially fixedly connected between the rotor sleeve and the end cover, the tensioning sleeve is sleeved on the outer side of the upper part of the hollow rotating shaft, and a first bearing is connected between the top of the stator sleeve and the outer side of the hollow rotating shaft. The first bearing includes a first bearing inner ring and a first bearing outer ring. The upper end of the first bearing inner ring is fixedly connected to the tensioning sleeve, and the lower end of the first bearing inner ring is fixedly connected to the upper end of the rotor sleeve. The inner side of the first bearing inner ring is fixedly connected to the hollow rotating shaft, and the first bearing outer ring is fixedly connected to the non-rotating guide disk and the stator sleeve.

[0012] A second bearing is connected between the bottom of the stator sleeve and the outer side of the hollow rotating shaft. The second bearing includes a second bearing inner ring and a second bearing outer ring. The upper end of the second bearing inner ring is fixedly connected to the lower end of the rotor sleeve, the inner side of the second bearing inner ring is fixedly connected to the hollow rotating shaft, the second bearing outer ring is fixedly connected to the stator sleeve, and a bearing end cover is fixedly connected to the bottom of the stator sleeve. The bearing end cover is sleeved on the outer periphery of the hollow rotating shaft, and the bearing end cover is fixedly connected to the lower end of the second bearing outer ring.

[0013] In some embodiments, the liquid inlet includes a first liquid inlet and a second liquid inlet, a dynamic sealing ring is connected between the stator sleeve and the rotor sleeve, and a static sealing ring is connected between the rotor sleeve 34 and the hollow shaft 31 .

[0014] In some embodiments, a detachable fixed connection tray is disposed in the mounting groove, and the bottom of the tray is connected to the workpiece via hot melt adhesive.

[0015] In some embodiments, a plurality of drainage grooves are provided at the bottom of the mounting plate, and the drainage grooves are respectively arranged between two adjacent mounting grooves and are interconnected with each other. The drainage grooves are connected to the liquid outlet holes, and the side walls of the drainage grooves are inclined surfaces inclined toward the bottom of the drainage grooves to drain the polishing liquid to the lower surface of the workpiece.

[0016] Another embodiment of the present invention provides an electromagnetic vibration cavitation assisted chemical mechanical polishing method, using the above chemical mechanical polishing device, comprising the following steps:

[0017] S1, install the workpiece to be polished at the bottom of the installation plate, adjust the installation height of the Y-axis guide rail on the column to obtain the best initial processing gap, and introduce polishing liquid from the liquid inlet so that there is a liquid film in the processing gap between the workpiece and the polishing plate;

[0018] S2, start the power supply of the polishing disc and the spindle servo motor of the polishing spindle, so that the polishing disc and the mounting disc rotate relative to each other, input high-frequency alternating current into the coil, so that the workpiece makes high-frequency axial vibration relative to the polishing disc, and the polishing liquid between the workpiece and the polishing disc produces cavitation effect;

[0019] S3, respectively start the motors of the x-axis guide and the y-axis guide, so that the polishing spindle reciprocates in the x-axis and y-axis directions, and use the PLC control module to make each motor move according to a given rule, so that the polishing trajectory is more uniform, and finally the surface quality of the workpiece meets the standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings.

[0021] in:

[0022] Figure 1 Schematic diagram of the structure of the electromagnetic vibration cavitation assisted chemical mechanical polishing device in an embodiment of the present invention;

[0023] Figure 2 for Figure 1 A schematic diagram of the structure of the guide rail module;

[0024] Figure 3 for Figure 1 A schematic diagram of the structure of the mounting frame in FIG.

[0025] Figure 4 for Figure 3 A schematic diagram of the structure of the electric slip ring fixing plate;

[0026] Figure 5 for Figure 3 A schematic diagram of the structure of the slotted chuck in FIG.

[0027] Figure 6 for Figure 1 A schematic diagram of the structure of the polishing spindle;

[0028] Figure 7 for Figure 1 A schematic diagram of the connection relationship between the mounting plate and the hollow shaft;

[0029] Figure 8 for Figure 7 A bottom view of the mounting plate in FIG.

[0030] Fig. 9 for Figure 7 A schematic diagram of the structure of the pallet;

[0031] Fig.10 A polishing principle diagram of a chemical mechanical polishing device assisted by electromagnetic vibration cavitation in an embodiment of the present invention;

[0032] Reference numerals:

[0033] 1. Polishing disc; 2. Guide rail module; 3. Mounting frame; 4. Polishing spindle; 5. Mounting disc; 6. First motor; 7. Lead screw; 8. Guide rod; 9. Slider; 10. Column; 11. Foot; 12. Slotted chuck; 13. Linear bearing; 14. Guide rod; 15. C-frame; 16. Screw; 17. Spindle servo motor; 18. Electric slip ring fixing plate; 19. Connecting shaft; 20. Iron core; 21. Upper fixing disc; 22. Permanent magnet; 23. Floating disc; 24. Blocking screw; 25. End cover; 26. Lower fixing disc; 27. First bearing; 28. Stator sleeve; 29. ​​Dynamic sealing ring; 30. First A joint; 31. hollow shaft; 32. bearing end cover; 33. static sealing ring; 34. rotor sleeve; 35. second joint; 36. non-rotating guide plate; 37. tensioning sleeve; 38. locking nut; 39. transition sleeve; 40. lower spring; 41. fixed sleeve; 42. optical axis; 43. upper spring; 44. coil; 45. electric slip ring; 46. coupling; 47. static sealing ring; 48. nut; 49. gasket; 50. elastic gasket; 51. tray; 52. workpiece; 53. drainage trough; 531. inclined surface; 54. gasket; 55. second bearing; 56. mounting groove; 57. liquid outlet. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0035] The following describes an electromagnetic vibration cavitation-assisted chemical mechanical polishing device and method according to an embodiment of the present invention with reference to the accompanying drawings.

[0036] like Figure 1-10 As shown, an embodiment of the present invention proposes an electromagnetic vibration cavitation assisted chemical mechanical polishing device, including: a polishing disc 1, a mounting frame 3, a polishing spindle 4 and a mounting disc 5, the mounting frame 3 is arranged above the polishing disc 1, and a spindle servo motor 17 is installed on the mounting frame 3, the output shaft of the spindle servo motor 17 is vertically downward, and the rotation direction of the output shaft of the spindle servo motor 17 is opposite to the rotation direction of the polishing disc 1.

[0037] The polishing spindle 4 is installed on the mounting frame 3, and the spindle servo motor 17 is connected to and drives the polishing spindle 4 to rotate along the z-axis. The polishing spindle 4 includes a connecting shaft 19, a hollow rotating shaft 31, a stator sleeve 28 and a vertical floating mechanism. The connecting shaft 19 and the output shaft of the spindle servo motor 17 are connected by a coupling 46. The vertical floating mechanism is connected between the connecting shaft 19 and the hollow rotating shaft 31. The vertical floating mechanism is suitable for driving the hollow rotating shaft 31 to rotate along the z-axis and vibrate back and forth in the vertical direction. The stator sleeve 28 is sleeved on the outer periphery of the hollow rotating shaft 31 and is in a non-rotating state. The stator sleeve 28 and the hollow rotating shaft 31 are rotationally connected through the rotor sleeve 34. The interior of the hollow rotating shaft 31 has a vertical through hole along the axial direction. The outer side of the stator sleeve 28 is provided with a liquid inlet for introducing polishing liquid. The rotor sleeve 34 and the hollow rotating shaft 31 are respectively provided with channels so that the liquid inlet is connected to the vertical through hole of the hollow rotating shaft 31.

[0038] The mounting plate 5 is detachably connected to the bottom of the hollow rotating shaft 31. A mounting groove 56 for clamping the workpiece 52 is provided at the bottom of the mounting plate 5. A liquid outlet 57 is provided at the center of the mounting plate 5. The liquid outlet 57 is connected to the vertical through hole so that the agent injected from the liquid inlet can be evenly coated on the lower surface of the workpiece 52. The lower surface of the workpiece 52 is suitable for contacting with the upper surface of the polishing plate 1 for polishing.

[0039] The embodiment of the present invention provides a polishing spindle 4, a mounting plate 5 and a polishing plate 1, so that the polishing liquid enters between the workpiece 52 and the polishing plate 1 to form a liquid film. When the mounting plate 5 and the polishing plate 1 rotate relative to each other, the uniformity of the polishing of the workpiece 52 can be improved. By providing a vertical floating mechanism, the workpiece 52 can be axially vibrated relative to the polishing plate 1 while the mounting plate 5 and the polishing plate 1 rotate relative to each other, thereby improving the polishing efficiency. The overall structure is compact, the design is reasonable, and the processing effect is good.

[0040] It should be noted that if Figure 1 As shown, the x-axis direction is the inside-out direction, the y-axis direction is the left-right direction, and the z-axis direction is the up-down direction. The polishing disc 1 is connected to the polishing mechanism, and the polishing disc 1 is independently controlled to rotate. Since the polishing mechanism is not the solution to be protected by the present invention, it is regarded as a conventional structure and will not be described in detail here.

[0041] Furthermore, the upper end of the mounting plate 5 has a boss at the center, and a thread groove is provided in the boss. The lower end of the hollow shaft 31 has an external thread matching the thread groove, and the mounting plate 5 is threadedly connected with the hollow shaft 31. The liquid outlet 57 runs through the bottom of the thread groove, so that the polishing liquid can enter the vertical through hole of the hollow shaft 31 along the liquid inlet, and then flow to the polishing plate 1 through the liquid outlet 57. Through the relative rotation between the polishing plate 1 and the mounting plate 5, the polishing liquid is evenly coated on the lower surface of the workpiece 52.

[0042] Furthermore, a static sealing ring 47 is provided at the connection between the inner side of the boss and the hollow rotating shaft 31 , and a gasket 54 is provided at the connection between the upper end of the boss and the hollow rotating shaft 31 .

[0043] In some embodiments, Figure 2 As shown, the chemical mechanical polishing device also includes a guide rail module 2, which includes a column 10, an x-axis guide rail and a y-axis guide rail. The y-axis guide rail is arranged in the horizontal direction, and a slider 9 is horizontally slidably connected to the y-axis guide rail. The mounting frame 3 is fixedly connected to the slider 9. The slider 9 moves horizontally along the y-axis guide rail, driving the mounting frame 3 to move synchronously. The column 10 is provided with two columns and is respectively fixedly connected to the bottom of the two ends of the y-axis guide rail. The bottom of each column 10 is respectively connected to an x-axis guide rail, and the two x-axis guide rails are respectively arranged on both sides of the polishing disk 1. The x-axis guide rail is arranged in the horizontal direction, and a foot seat 11 is horizontally slidably connected to the x-axis guide rail. The bottom of the column 10 is fixedly connected to the foot seat 11. The two foot seats 11 move horizontally synchronously along the x-axis guide rail, driving the column 10 and the y-axis guide rail to move synchronously.

[0044] By setting the guide rail module 2, the polishing spindle 4 can be controlled to move along the x-axis direction and the y-axis direction, thereby controlling the polishing path to form a specific uniform polishing track.

[0045] Furthermore, the x-axis guide includes a first housing, a lead screw 7 and a first motor 6, and the y-axis guide includes a second housing, a guide rod 8 and a second motor. The lead screw runs through the first housing and is rotatably connected to the first housing. The first motor 6 is connected to the end of the lead screw and drives the lead screw to rotate. The lead screw of the x-axis guide drives the foot 11 to move horizontally along the x-axis direction. The guide rod 8 runs through the second housing and is rotatably connected to the second housing. The second motor is connected to the end of the guide rod 8 and drives the guide rod 8 to rotate. The guide rod 8 of the y-axis guide drives the slider 9 to move horizontally along the y-axis direction. Both the first motor 6 and the second motor are servo motors, which facilitates precise control of the moving position of the slider 9 and the foot 11.

[0046] Furthermore, the column 10 is a liftable column.

[0047] In some embodiments, Figure 3 , 5As shown, the mounting frame 3 includes a C-shaped frame 15, a guide rod 14 and a slotted chuck 12. The C-shaped frame 15 includes an upper end plate, a back plate and a lower end plate. The upper end plate and the lower end plate are arranged in parallel. The back plate is fixedly connected between the upper end plate and the lower end plate to form a C-shaped structure. The housing of the spindle servo motor 17 is installed on the upper end plate. The output shaft of the spindle servo motor 17 vertically penetrates the upper end plate downward. The lower end plate is provided with an opening for the polishing spindle 4 to pass through. A plurality of guide rods 14 are evenly distributed. The slotted chuck 12 is fixedly connected to the lower end plate through the guide rods 14. A linear bearing 13 is slidably connected to each guide rod 14, a stator sleeve 28 is fixedly connected to a non-rotating guide plate 36, all guide rods 14 penetrate the non-rotating guide plate 36 in a vertical direction, and the non-rotating guide plate 36 is fixedly connected to all linear bearings 13 at the penetration point of the guide rod 14, so that the non-rotating guide plate 36 slides along the axial direction of the guide rod 14, and a C-shaped opening is opened from the center to the edge of the slotted chuck 12, so that the stator sleeve 28 can be clamped into the slotted chuck 12 and slide synchronously with the non-rotating guide plate 36 in the vertical direction.

[0048] Furthermore, the non-rotating guide plate 36 and the linear bearing 13 are threadedly connected.

[0049] In some embodiments, Figure 3 , 4 As shown in FIG. 6 , an electric slip ring 45 is sleeved on the connecting shaft 19 , and an electric slip ring fixing plate 18 is fixedly connected to the lower part of the upper end plate through a screw 16 and a nut 48 , and the outer side of the electric slip ring 45 is mounted on the electric slip ring fixing plate 18 .

[0050] Furthermore, the electric slip ring fixing plate 18 is provided with a semi-open notch structure to facilitate the assembly and disassembly of the electric slip ring 45 .

[0051] In some embodiments, Figure 6As shown, the vertical floating mechanism includes an upper fixed plate 21, a lower fixed plate 26, a floating plate 23, an optical axis 42, an iron core 20, a coil 44 and a permanent magnet 22. A plurality of optical axes 42 are evenly distributed around the edge of the upper fixed plate 21 and connected between the upper fixed plate 21 and the lower fixed plate 26. The upper fixed plate 21 is fixedly connected to the bottom of the connecting shaft 19. The iron core 20 is fixedly connected to the center of the upper fixed plate 21. The coil 44 is wound around the outer side of the iron core 20. The floating plate 23 is arranged between the upper fixed plate 21 and the lower fixed plate 26. All optical axes 42 pass through the edge of the floating plate 23. Each optical axis 42 is sleeved with an upper spring 43 and a lower spring 40. The upper spring 43 is connected between the floating plate 23 and the upper fixed plate 21, and the lower spring 40 is connected between the floating plate 23 and the lower fixed plate 26. The floating plate 23 floats up and down along the axial direction of the optical axis 42. The upper end of the floating plate 23 is fixedly connected to the permanent magnet 22. The iron core 20 is located directly above the permanent magnet 22. The floating plate 23 is fixedly connected to the hollow rotating shaft 31. When high-frequency alternating current is passed through the coil 44, the iron core 20 and the coil 44 generate an alternating force of attraction and repulsion on the permanent magnet 22, driving the floating plate 23 to float up and down along the optical axis 42 and gradually self-balance, thereby driving the mounting plate 5 and the workpiece 52 to vibrate up and down while rotating on the polishing plate 1.

[0052] The electromagnetic module composed of the iron core 20 and the coil 44 is coaxially installed with the permanent magnet 22. When high-frequency alternating current is passed through the coil 44, an alternating force of attraction and repulsion is generated on the permanent magnet 22, thereby generating an axial vibration effect. At the same time, the optical axis 42, the upper spring 43 and the lower spring 40 respectively guide and buffer the vibration of the hollow shaft 31. Under the action of electromagnetic vibration, the liquid film formed between the workpiece 52 and the polishing disc 1 is subjected to high-frequency alternating forces, thereby generating a cavitation effect and promoting the chemical mechanical polishing effect.

[0053] It should be noted that the coil 44 is energized during the rotation process using conventional methods such as carbon brushes.

[0054] Furthermore, the longitudinal section of the core 20 is T-shaped, the upper portion of the core 20 is disc-shaped, the lower portion of the core 20 is cylindrical, and the outer diameter of the upper portion of the core 20 is greater than the outer diameter of the lower portion. The upper portion of the core 20 is fixed between the upper fixing plate 21 and the connecting shaft 19 by bolts.

[0055] In some embodiments, Figure 6As shown, a fixed sleeve 41, a transition sleeve 39 and a tensioning sleeve 37 are connected between the floating plate 23 and the hollow rotating shaft 31. The fixed sleeve 41, the transition sleeve 39 and the tensioning sleeve 37 are connected in sequence from top to bottom. The fixed sleeve 41 is coaxially fixedly connected to the bottom of the center of the floating plate 23, the transition sleeve 39 is coaxially fixedly connected to the bottom of the fixed sleeve 41, the end cover 25 is fixedly connected between the transition sleeve 39 and the hollow rotating shaft 31, and the tensioning sleeve 37 is coaxially fixedly connected to the rotor sleeve 34 and the end cover 2 5, a tensioning sleeve 37 is sleeved on the outer side of the upper part of the hollow rotating shaft 31, a first bearing 27 is connected between the top of the stator sleeve 28 and the outer side of the hollow rotating shaft 31, the first bearing 27 includes a first bearing inner ring and a first bearing outer ring, the upper end of the first bearing inner ring is fixedly connected to the tensioning sleeve 37, the lower end of the first bearing inner ring is fixedly connected to the upper end of the rotor sleeve 34, the inner side of the first bearing inner ring is fixedly connected to the hollow rotating shaft 31, and the first bearing outer ring is fixedly connected to the non-rotating guide plate 36 and the stator sleeve 28.

[0056] A second bearing 55 is connected between the bottom of the stator sleeve 28 and the outer side of the hollow shaft 31. The second bearing 55 includes a second bearing inner ring and a second bearing outer ring. The upper end of the second bearing inner ring is fixedly connected to the lower end of the rotor sleeve 34, the inner side of the second bearing inner ring is fixedly connected to the hollow shaft 31, the second bearing outer ring is fixedly connected to the stator sleeve 28, and the bottom of the stator sleeve 28 is fixedly connected to a bearing end cover 32. The bearing end cover 32 is sleeved on the outer periphery of the hollow shaft 31, and the bearing end cover 32 is fixedly connected to the lower end of the second bearing outer ring.

[0057] By providing the fixed sleeve 41 , the transition sleeve 39 and the tension sleeve 37 , the alternating force generated by the electromagnetic module and the permanent magnet 22 is transmitted to the hollow shaft 31 via the fixed sleeve 41 , the transition sleeve 39 and the tension sleeve 37 , thereby generating an axial vibration effect.

[0058] Furthermore, the end cover 25 is fixed to the top of the hollow shaft 31 by means of the plugging screw 24 and the locking nut 38 .

[0059] In some embodiments, Figure 6 As shown, the liquid inlet includes a first liquid inlet and a second liquid inlet, a dynamic sealing ring 29 is connected between the stator sleeve 28 and the rotor sleeve 34 , and a static sealing ring 33 is connected between the rotor sleeve 34 and the hollow rotating shaft 31 .

[0060] The first liquid inlet and the second liquid inlet are used to introduce polishing liquids or chemical additives of different properties.

[0061] Furthermore, the first liquid inlet is connected to the first connector 30 , and the second liquid inlet is connected to the second connector 35 , which makes liquid injection more convenient.

[0062] Furthermore, the rotor sleeve 34 and the side wall of the hollow shaft 31 are both provided with annular grooves, and each annular groove is evenly provided with four radial holes, and the liquid inlet is connected with the annular groove, so that during the rotation of the hollow shaft 31, the polishing liquid is introduced into the vertical through hole of the hollow shaft 31 through the annular groove and the radial holes, thereby effectively entering the polishing area. This design can effectively avoid the problem of reactive polishing liquid becoming ineffective due to excessive reaction and consumption after external mixing.

[0063] In some embodiments, Figure 7-9 As shown, the tray 51 is detachably fixedly connected in the mounting groove 56, and the bottom of the tray 51 is connected to the workpiece 52 by hot melt adhesive.

[0064] When the workpiece 52 is polished, the tray 51 on which the workpiece 52 is attached is taken out from the mounting groove 56 and placed in a heating box or oven for heating to completely melt the hot melt adhesive, thereby separating the workpiece 52 from the tray 51 and then taking the workpiece 52 out.

[0065] Furthermore, one side of the tray 51 is used to stick the workpiece 52, and a threaded column is provided at the center of the other side, which passes through the bottom of the mounting groove 56 and is screwed and fixed by a nut 48, and a gasket 49 is provided between the nut 48 and the mounting groove 56. An elastic gasket 50 is provided between the tray 51 and the mounting groove 56 to provide a buffering effect on the workpiece 52 during the polishing process.

[0066] In some embodiments, Figure 7 , 8 As shown, a plurality of drainage grooves 53 are provided at the bottom of the mounting plate 5. The drainage grooves 53 are respectively arranged between two adjacent mounting grooves 56 and the two adjacent drainage grooves 53 are interconnected. The drainage grooves 53 are connected to the liquid outlet holes 57. The side walls of the drainage grooves 53 are inclined surfaces 531 inclined toward the bottom of the drainage grooves 53 so as to drain the polishing liquid to the lower surface of the workpiece 52.

[0067] By setting up a drainage groove 53 and designing the inner wall of the drainage groove 53 as an inclined surface 531, on the one hand, it is convenient to drain the polishing liquid along the inclined surface 531 to the lower surface of the workpiece 52; on the other hand, since the groove body is located between two adjacent mounting grooves 56 and the center position of the mounting plate 5, the contact surface area between the mounting plate 5 and the polishing plate 1 is reduced, thereby increasing the squeezing force of the polishing plate 1 on the workpiece 52, thereby improving the polishing efficiency.

[0068] like Fig.10 As shown, another embodiment of the present invention provides an electromagnetic vibration cavitation assisted chemical mechanical polishing method, using the above chemical mechanical polishing device, including the following steps:

[0069] S1, install the workpiece 52 to be polished at the bottom of the mounting plate 5, adjust the installation height of the y-axis guide rail on the column 10 to obtain the best initial machining gap, and introduce polishing liquid from the liquid inlet so that a liquid film exists in the machining gap between the workpiece 52 and the polishing plate 1;

[0070] S2, start the power supply of the polishing disc 1 and the spindle servo motor 17 of the polishing spindle 4, so that the polishing disc 1 and the mounting disc 5 rotate relative to each other, input high-frequency alternating current to the coil 44, so that the workpiece 52 performs high-frequency axial vibration relative to the polishing disc 1, so that the polishing liquid between the workpiece 52 and the polishing disc 1 produces cavitation effect;

[0071] S3, respectively start the motors of the x-axis guide and the y-axis guide, so that the polishing spindle 4 reciprocates in the x-axis and y-axis directions, and use the PLC control module to make each motor move according to a given rule, so that the polishing track is more uniform, and finally the surface quality of the workpiece 52 meets the standard.

[0072] The method of the embodiment of the present invention can make the polishing liquid enter between the workpiece 52 and the polishing disc 1 to form a liquid film, and when the mounting disc 5 and the polishing disc 1 rotate relative to each other, the uniformity of the polishing of the workpiece 52 can be improved. And when the mounting disc 5 and the polishing disc 1 rotate relative to each other, the workpiece 52 is axially vibrated relative to the polishing disc 1, thereby improving the polishing efficiency.

[0073] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0074] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0075] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0076] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0077] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0078] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A chemical mechanical polishing device assisted by electromagnetic vibration cavitation, characterized in that: include: Polishing discs; A mounting frame, the mounting frame is arranged above the polishing disc, a spindle servo motor is mounted on the mounting frame, an output shaft of the spindle servo motor is vertically downward, and a rotation direction of the output shaft of the spindle servo motor is opposite to a rotation direction of the polishing disc; A polishing spindle, wherein the polishing spindle is mounted on the mounting frame, the spindle servo motor is connected to and drives the polishing spindle to rotate along the z-axis, the polishing spindle comprises a connecting shaft, a hollow rotating shaft, a stator sleeve and a vertical floating mechanism, the connecting shaft and the output shaft of the spindle servo motor are connected via a coupling, the vertical floating mechanism is connected between the connecting shaft and the hollow rotating shaft, the vertical floating mechanism is suitable for driving the hollow rotating shaft to reciprocate and vibrate in the vertical direction while rotating along the z-axis, the stator sleeve is sleeved on the outer circumference of the hollow rotating shaft, the stator sleeve and the hollow rotating shaft are rotationally connected via a rotor sleeve, the interior of the hollow rotating shaft has a vertical through hole along the axial direction, the outer side of the stator sleeve is provided with a liquid inlet for introducing polishing liquid, the rotor sleeve and the hollow rotating shaft are respectively provided with channels so that the liquid inlet is communicated with the vertical through hole of the hollow rotating shaft; A mounting plate is detachably connected to the bottom of the hollow rotating shaft, a mounting groove for clamping a workpiece is provided at the bottom of the mounting plate, a liquid outlet is provided at the center of the mounting plate, and the liquid outlet is communicated with the vertical through hole so that the agent injected from the liquid inlet can be evenly coated on the lower surface of the workpiece, and the lower surface of the workpiece is suitable for contacting with the upper surface of the polishing plate for polishing.

2. The electromagnetic vibration cavitation assisted chemical mechanical polishing device according to claim 1, characterized in that: It also includes a guide rail module, which includes a column, an x-axis guide rail and a y-axis guide rail. The y-axis guide rail is arranged in a horizontal direction, and a slider is horizontally slidably connected to the y-axis guide rail. The mounting frame is fixedly connected to the slider. The slider moves horizontally along the y-axis guide rail, driving the mounting frame to move synchronously. The column is provided with two columns and is respectively fixedly connected to the bottom of the two ends of the y-axis guide rail. The bottom of each column is respectively connected to an x-axis guide rail. The two x-axis guide rails are respectively arranged on both sides of the polishing disk. The x-axis guide rail is arranged in a horizontal direction, and a foot seat is horizontally slidably connected to the x-axis guide rail. The bottom of the column is fixedly connected to the foot seat. The two foot seats move horizontally synchronously along the x-axis guide rail, driving the column and the y-axis guide rail to move synchronously.

3. The electromagnetic vibration cavitation assisted chemical mechanical polishing device according to claim 1, characterized in that: The mounting frame includes a C-shaped frame, a guide rod and a slotted chuck, the C-shaped frame includes an upper end plate, a back plate and a lower end plate, the upper end plate and the lower end plate are arranged in parallel, the back plate is fixedly connected between the upper end plate and the lower end plate to form a C-shaped structure, the housing of the spindle servo motor is installed on the upper end plate, the output shaft of the spindle servo motor vertically penetrates the upper end plate downward, the lower end plate is provided with an opening for the polishing spindle to pass through, the guide rods are evenly distributed, and the slotted chuck is fixedly connected through the guide rods Below the lower end plate, each guide rod is slidably connected with a linear bearing, the stator sleeve is fixedly connected to a non-rotating guide plate, all the guide rods penetrate the non-rotating guide plate in a vertical direction, and the non-rotating guide plate is fixedly connected to all the linear bearings at the points where the guide rods penetrate, so that the non-rotating guide plate slides along the axial direction of the guide rods, and the slotted chuck is provided with a C-shaped opening from the center to the edge, so that the stator sleeve can be clamped into the slotted chuck and slide synchronously with the non-rotating guide plate in the vertical direction.

4. The electromagnetic vibration cavitation assisted chemical mechanical polishing device according to claim 3, characterized in that: An electric slip ring is sleeved on the connecting shaft, and an electric slip ring fixing plate is fixedly connected to the lower side of the upper end plate through a screw and a nut, and the outer side of the electric slip ring is mounted on the electric slip ring fixing plate.

5. The electromagnetic vibration cavitation assisted chemical mechanical polishing device according to claim 3, characterized in that: The vertical floating mechanism includes an upper fixed plate, a lower fixed plate, a floating plate, an optical axis, an iron core, a coil and a permanent magnet. Several optical axes are evenly distributed around the edge of the upper fixed plate and connected between the upper fixed plate and the lower fixed plate. The upper fixed plate is fixedly connected to the bottom of the connecting shaft. The iron core is fixedly connected to the center of the upper fixed plate. The coil is wound around the outside of the iron core. The floating plate is arranged between the upper fixed plate and the lower fixed plate. All the optical axes pass through the edge of the floating plate. Each of the optical axes is sleeved with an upper spring and a lower spring. The upper spring is connected to the bottom of the connecting shaft. The floating plate is connected between the floating plate and the upper fixed plate, and the lower spring is connected between the floating plate and the lower fixed plate. The floating plate floats up and down along the axial direction of the optical axis. The upper end of the floating plate is fixedly connected to a permanent magnet. The iron core is located directly above the permanent magnet. The floating plate is fixedly connected to the hollow rotating shaft. When high-frequency alternating current is passed through the coil, the iron core and the coil generate an alternating force of attraction and repulsion on the permanent magnet, driving the floating plate to float up and down along the optical axis, thereby driving the mounting plate and the workpiece to vibrate up and down while rotating on the polishing plate.

6. The electromagnetic vibration cavitation assisted chemical mechanical polishing device according to claim 5, characterized in that: A fixed sleeve, a transition sleeve and a tensioning sleeve are connected between the floating plate and the hollow rotating shaft, the fixed sleeve, the transition sleeve and the tensioning sleeve are connected in sequence from top to bottom, the fixed sleeve is coaxially fixedly connected to the bottom of the center of the floating plate, the transition sleeve is coaxially fixedly connected to the bottom of the fixed sleeve, an end cover is fixedly connected between the transition sleeve and the hollow rotating shaft, the tensioning sleeve is coaxially fixedly connected between the rotor sleeve and the end cover, the tensioning sleeve is sleeved on the outer side of the upper part of the hollow rotating shaft, a first bearing is connected between the top of the stator sleeve and the outer side of the hollow rotating shaft, the first bearing comprises a first bearing inner ring and a first bearing outer ring, the upper end of the first bearing inner ring is fixedly connected to the tensioning sleeve, the lower end of the first bearing inner ring is fixedly connected to the upper end of the rotor sleeve, the inner side of the first bearing inner ring is fixedly connected to the hollow rotating shaft, and the first bearing outer ring is fixedly connected to the non-rotating guide plate and the stator sleeve; A second bearing is connected between the bottom of the stator sleeve and the outer side of the hollow shaft, the second bearing includes a second bearing inner ring and a second bearing outer ring, the upper end of the second bearing inner ring is fixedly connected to the lower end of the rotor sleeve, the inner side of the second bearing inner ring is fixedly connected to the hollow shaft, the second bearing outer ring is fixedly connected to the stator sleeve, the bottom of the stator sleeve is fixedly connected to a bearing end cover, the bearing end cover is sleeved on the outer circumference of the hollow shaft, and the bearing end cover is fixedly connected to the lower end of the second bearing outer ring.

7. The electromagnetic vibration cavitation assisted chemical mechanical polishing device according to claim 1, characterized in that: The liquid inlet includes a first liquid inlet and a second liquid inlet, a dynamic sealing ring is connected between the stator sleeve and the rotor sleeve, and a static sealing ring is connected between the rotor sleeve and the hollow rotating shaft.

8. The electromagnetic vibration cavitation assisted chemical mechanical polishing device according to claim 1, characterized in that: A tray is detachably fixedly connected in the installation groove, and the bottom of the tray is connected to the workpiece by hot melt adhesive.

9. The electromagnetic vibration cavitation assisted chemical mechanical polishing device according to claim 8, characterized in that: A plurality of drainage grooves are provided at the bottom of the mounting plate, and the drainage grooves are respectively arranged between two adjacent mounting grooves and are interconnected with each other. The drainage grooves are connected to the liquid outlet holes, and the side walls of the drainage grooves are inclined surfaces inclined toward the bottom of the drainage grooves so as to drain the polishing liquid to the lower surface of the workpiece.

10. A chemical mechanical polishing method assisted by electromagnetic vibration cavitation, characterized in that: The chemical mechanical polishing device according to any one of claims 1 to 9 comprises the following steps: S1, installing the workpiece to be polished at the bottom of the mounting plate, adjusting the installation height of the Y-axis guide rail on the column to obtain the best initial machining gap, and introducing polishing liquid from the liquid inlet so that a liquid film exists in the machining gap between the workpiece and the polishing plate; S2, starting the power supply of the polishing disc and the spindle servo motor of the polishing spindle, so that the polishing disc and the mounting disc rotate relative to each other, inputting high-frequency alternating current into the coil, so that the workpiece performs high-frequency axial vibration relative to the polishing disc, and causing the polishing liquid between the workpiece and the polishing disc to produce cavitation effect; S3, respectively start the motors of the x-axis guide rail and the y-axis guide rail, so that the polishing spindle reciprocates in the x-axis and y-axis directions, and use the PLC control module to make each motor move according to a given rule, so that the surface quality of the workpiece finally meets the standard.

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