Grinding and polishing integrated method and apparatus for diamond wafer

Abstract

A grinding and polishing integrated method and apparatus for a diamond wafer. The method comprises: grinding sequentially with a porous ceramic-based diamond grinding wheel, a resin-based diamond grinding wheel, and a chemical reaction grinding wheel in a grinding stage; and polishing sequentially with a diamond abrasive polishing solution, an alumina abrasive polishing solution, and a titanium dioxide abrasive polishing solution in a polishing stage. The grinding and polishing integrated apparatus comprises a Z-axis feeding device (1), an X-axis reciprocating device (2), a hollow rotating spindle assembly (3), a polishing disc assembly (4), a marble platform (6), a waste liquid pool (7), and a human-machine interaction and control module (8). By means of grinding and polishing in stages, surface roughness of the diamond wafer is reduced step by step, and efficient and ultra-smooth polishing of the diamond wafer of 50-220 mm is implemented, so that an ultra-smooth and flat surface of Ra0.001 can be obtained.

Description

A method and device for integrated grinding and polishing of diamond wafers Technical Field

[0001] The present invention belongs to the technical field of semiconductor manufacturing, and in particular relates to an integrated grinding and polishing method and device for diamond wafers. Background Art

[0002] As a semiconductor material, diamond's greatest advantages lie in its extremely high carrier mobility, higher breakdown electric field, and greater thermal conductivity. Not only is diamond the hardest material in nature, it also boasts a thermal conductivity 22 times that of silicon and five times that of copper. It also boasts excellent electrical insulation, a wide optical transmission band, exceptional semiconductor properties, and chemical inertness, making it one of the most ideal materials for semiconductor manufacturing.

[0003] However, precisely because of diamond's many properties, its processing has become the biggest obstacle to its widespread application. Due to diamond's extremely high hardness and extremely low coefficient of friction, traditional machining methods are nearly impossible to produce diamond products. Furthermore, the cross-sections produced by later-emerging machining methods like laser and plasma beam machining are too rough, seriously affecting the machining accuracy of diamond.

[0004] Therefore, in order to solve the above-mentioned technical problems, it is necessary to provide an integrated grinding and polishing method and device for diamond wafers.

[0005] Summary of the Invention

[0006] The purpose of the present invention is to provide an integrated grinding and polishing method and device for diamond wafers to solve the technical problems in the prior art that diamond processing is difficult due to the many characteristics of diamond, and the cross-section obtained by traditional processing methods is too rough, which seriously affects the diamond processing accuracy.

[0007] A first aspect of the present invention provides an integrated grinding and polishing method for a diamond wafer, the specific steps of the method comprising:

[0008] S1: Using the porous ceramic-based diamond grinding wheel on the hollow rotating spindle assembly, combined with the X-axis reciprocating device and the Z-axis feeding device, the diamond wafer adsorbed on the top of the polishing plate assembly is roughly ground to reduce the surface roughness of the diamond wafer to Ra0.05 to Ra0.03;

[0009] S2: The porous ceramic-based diamond grinding wheel on the hollow rotating spindle assembly is replaced with a resin-based diamond grinding wheel, and the diamond wafer is subjected to the first fine grinding, reducing the surface roughness of the diamond wafer to Ra0.01 to Ra0.005;

[0010] S3: replacing the resin-based diamond grinding wheel on the hollow rotating spindle assembly with a chemical reaction grinding wheel, and then performing a second fine grinding on the diamond wafer, reducing the surface roughness of the diamond wafer to Ra0.005 to Ra0.003, thereby completing the grinding of the diamond wafer;

[0011] S4: The human-machine interaction and control module controls the Z-axis feed device to lift the hollow rotating spindle assembly, replaces the chemical reaction grinding wheel with a polishing pad assembly, adds diamond abrasive polishing liquid to the polishing liquid dripping tube in the hollow rotating spindle assembly, and then roughly polishes the diamond wafer to reduce the surface roughness of the diamond wafer to Ra0.002 to Ra0.001;

[0012] In step S4, the diamond abrasive polishing liquid includes an oxidant, a catalyst, an acid-base regulator and a diamond abrasive solution;

[0013] S5: replacing the diamond abrasive polishing liquid in the polishing liquid dripping tube with an aluminum oxide abrasive polishing liquid, and then performing the first fine polishing on the diamond wafer to reduce the surface roughness of the diamond wafer to Ra0.001 to Ra0.0005;

[0014] In step S5, the aluminum oxide abrasive polishing liquid includes an oxidant, a catalyst, an acid-base regulator, and an aluminum oxide abrasive solution;

[0015] S6: replacing the aluminum oxide abrasive polishing liquid in the polishing liquid dripping tube with a titanium dioxide abrasive polishing liquid, and then performing a second fine polishing on the diamond wafer to remove scratches and adsorbents remaining on the surface of the diamond wafer, thereby obtaining a diamond wafer;

[0016] In step S6 , the titanium dioxide abrasive polishing liquid includes an oxidant, a catalyst, an acid-base regulator, and a titanium dioxide abrasive solution.

[0017] Optionally, the oxidant includes any one of a K2FeO4 solution or a H2O2 solution.

[0018] Optionally, the catalyst comprises a FeSO4 solution.

[0019] Optionally, the acid-base regulator is a phosphoric acid standard solution.

[0020] The second aspect of the present invention provides a device for an integrated method of grinding and polishing diamond wafers, comprising: a base support; a marble platform, arranged above the base support and connected to the base; a waste liquid tank, arranged above the marble platform and connected to the marble platform; a polishing disc assembly, arranged above the marble platform and connected to the marble platform; a gantry, arranged on one side above the marble platform, adjacent to the waste liquid tank, and connected to the marble platform; an X-axis reciprocating device, arranged above the gantry and connected to the gantry; a Z-axis feeding device, arranged above the X-axis reciprocating device and connected to the X-axis reciprocating device; a hollow rotating spindle assembly, arranged on the side of the Z-axis feeding device and connected to the Z-axis feeding device; a human-computer interaction and control module, arranged above the gantry and connected to the gantry, and electrically connected to both the X-axis reciprocating device and the Z-axis feeding device; and a polishing pad assembly, arranged at the bottom of the hollow rotating spindle assembly and connected to the hollow rotating spindle assembly.

[0021] Optionally, the hollow rotating spindle assembly includes: a frame, which is arranged on the side of the Z-axis feed device and connected to the Z-axis feed device; a hollow spindle, which is arranged on one side of the frame and connected to the frame; a rotating shell end cover, which is arranged above the rotating shell and connected to the rotating shell; a bearing fixing end cover, which is arranged below the rotating shell end cover and connected to the rotating shell end cover; a double-row angular contact ball bearing, which is arranged below the rotating shell end cover and connected to the rotating shell end cover; a rotating shell, which is arranged on the outside of the double-row angular contact ball bearing and connected to the double-row angular contact ball bearing; a frameless motor, which is arranged between the hollow spindle and the rotating shell and connected to the hollow spindle; a spindle end cover, which is arranged at the bottom of the hollow spindle and connected to the hollow spindle; a storage tray, which is arranged at the bottom of the spindle end cover and connected to the spindle end cover; a polishing liquid droplet tube, which is arranged at the lower end of the storage tray and connected to the storage tray.

[0022] Optionally, the hollow rotating spindle assembly further includes: an ultraviolet lamp head, which is arranged at the lower end of the placement tray and connected to the placement tray; and an ultraviolet shielding cover, which is arranged below the rotating shell and connected to the rotating shell.

[0023] Optionally, the polishing pad assembly further includes: a polishing pad base, which is arranged below the ultraviolet shielding cover and connected to the polishing pad base; and a polishing pad, which is arranged at the bottom of the polishing pad base and connected to the polishing pad base.

[0024] Optionally, the polishing disc assembly includes: a base, which is arranged above the marble platform and connected to the marble platform; a direct-drive rotary motor, which is arranged above the base and connected to the base; a polishing disc rotating chassis, which is arranged above the direct-drive rotary motor and connected to the direct-drive rotary motor; a cylindrical guide rail, which is arranged above the polishing disc rotating chassis and connected to the polishing disc rotating chassis; a floating disc, which is arranged above the cylindrical guide rail and connected to the cylindrical guide rail, thereby limiting the movement of the floating disc through the cylindrical guide rail; a magnetic levitation pillar, which is arranged at the bottom of the floating disc and connected to the floating disc, thereby providing magnetic levitation for the floating disc; a porous ceramic suction cup, which is arranged above the floating disc and connected to the floating disc; an air supply pipe, which is passed through the interior of the direct-drive rotary motor and the floating disc and is connected to the porous ceramic suction cup; a high-speed air slip ring, which is sleeved on the end of the air supply pipe close to the porous ceramic suction cup and is connected to the air supply pipe.

[0025] Compared with the prior art, the present invention provides an integrated grinding and polishing method and device for diamond wafers. The present invention divides the grinding and polishing process into six stages: rough grinding, first fine grinding, second fine grinding, rough polishing, first fine polishing, and second fine polishing. By performing grinding and polishing in stages, the surface roughness of the diamond wafer is gradually reduced, and rapid flattening of the diamond wafer is achieved by grinding with a diamond grinding wheel and a chemical reaction grinding wheel to ensure the surface accuracy of the diamond wafer. Subsequently, chemical mechanical polishing is performed in situ to achieve low-damage surface polishing of the diamond wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0027] FIG1 is a schematic flow diagram of an integrated grinding and polishing method for diamond wafers according to the present invention;

[0028] FIG2 is a schematic diagram of the overall structure of the integrated grinding and polishing device for diamond wafers of the present invention;

[0029] FIG3 is a schematic structural diagram of the hollow rotating spindle of the integrated grinding and polishing device for diamond wafers of the present invention;

[0030] FIG4 is a schematic structural diagram of a polishing disc assembly of the integrated grinding and polishing device for diamond wafers according to the present invention;

[0031] FIG5 is a schematic diagram of the gas and liquid paths of the integrated grinding and polishing apparatus for diamond wafers of the present invention.

[0032] Explanation of the accompanying symbols: 1. Z-axis feed device; 2. X-axis reciprocating device; 3. Hollow rotating spindle assembly; 301. Frame; 302. Rotating housing end cover; 303. Double-row angular contact ball bearing; 304. Bearing fixed end cover; 305. Motor outer rotor; 306. Motor inner stator; 307. Polishing liquid dripping tube; 308. Polishing pad; 309. Polishing pad base; 310. UV lamp head; 311. UV shielding cover; 312. Storage tray; 313. Spindle end cover; 314. Rotating housing; 315. Coaxial cooling fan; 316. Hollow spindle; 4. Polishing disc assembly; 401. Porous ceramic suction cup; 402. Floating disc; 403. Cylindrical guide rail; 404. Polishing disc rotating chassis; 406. Direct-drive rotating motor; 407. Air supply pipe; 410. Magnetic levitation support; 411. High-speed air slip ring; 5. Diamond wafer; 6. Marble platform; 7. Waste liquid tank; 8. Human-computer interaction and control module; 9. Polishing liquid reflux pipe. DETAILED DESCRIPTION

[0033] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.

[0034] It should be noted that, unless otherwise specified, technical or scientific terms used herein should have the ordinary meanings understood by those skilled in the art to which the present invention pertains. In this document, relational terms such as "first" and "second" are used solely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Terms such as "connected" and "connected" should be interpreted broadly, meaning, for example, fixedly connected, removably connected, or integrally connected; mechanically connected, electrically connected; directly connected, or indirectly connected through an intermediary. The terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Without further limitation, the phrase "comprises..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus comprising the elements.

[0035] As shown in FIG1 , this embodiment provides an integrated method for grinding and polishing a diamond wafer, the specific steps of the method comprising:

[0036] S1: Using the porous ceramic-based diamond grinding wheel on the hollow rotating spindle assembly 3, combined with the X-axis reciprocating device 2 and the Z-axis feeding device 1, the diamond wafer adsorbed on the top of the polishing plate assembly 4 is roughly ground to reduce the surface roughness of the diamond wafer to Ra0.05 to Ra0.03;

[0037] S2: replacing the porous ceramic-based diamond grinding wheel on the hollow rotating spindle assembly 3 with a resin-based diamond grinding wheel, and then performing the first fine grinding on the diamond wafer to reduce the surface roughness of the diamond wafer to Ra0.01 to Ra0.005;

[0038] S3: replacing the resin-based diamond grinding wheel on the hollow rotating spindle assembly 3 with a chemical reaction grinding wheel, and then performing a second fine grinding on the diamond wafer to reduce the surface roughness of the diamond wafer to Ra0.005 to Ra0.003, thereby completing the grinding of the diamond wafer;

[0039] S4: The human-machine interaction and control module 8 controls the Z-axis feeding device 1 to lift the hollow rotating spindle assembly 3, replaces the chemical reaction grinding wheel with the polishing pad 308 assembly, adds diamond abrasive polishing liquid to the polishing liquid dripping pipe 307 in the hollow rotating spindle assembly 3, and then roughly polishes the diamond wafer to reduce the surface roughness of the diamond wafer to Ra0.002 to Ra0.001;

[0040] In step S4, the diamond abrasive polishing liquid includes an oxidant, a catalyst, an acid-base regulator and a diamond abrasive solution;

[0041] S5: replacing the diamond abrasive polishing liquid in the polishing liquid dripping tube 307 with an aluminum oxide abrasive polishing liquid, and then performing a first fine polishing on the diamond wafer to reduce the surface roughness of the diamond wafer to Ra0.001 to Ra0.0005;

[0042] In step S5, the aluminum oxide abrasive polishing liquid includes an oxidant, a catalyst, an acid-base regulator, and an aluminum oxide abrasive solution;

[0043] S6: replacing the aluminum oxide abrasive polishing liquid in the polishing liquid dripping tube 307 with a titanium dioxide abrasive polishing liquid, and then performing a second fine polishing on the diamond wafer to remove the scratches and adsorbents remaining on the surface of the diamond wafer, thereby obtaining a diamond wafer;

[0044] In step S6 , the titanium dioxide abrasive polishing liquid includes an oxidant, a catalyst, an acid-base regulator, and a titanium dioxide abrasive solution.

[0045] In one possible embodiment, the oxidant includes either a K 2 FeO 4 solution or a H 2 O 2 solution.

[0046] In one possible embodiment, the catalyst is FeSO4.

[0047] In a possible embodiment, the acid-base regulator is a phosphoric acid standard solution.

[0048] In this embodiment, before use, the working space of the device is checked for obstacles, and the air supply device, polishing liquid supply device, and power supply device are checked to ensure they are functioning properly. After powering on, the device performs a self-check, turns on the 24V control power supply, and releases the power-off locks on each axis. After the control device is powered on, the device completes initialization, automatically returns to the zero position, and then enters standby mode.

[0049] The 4-inch diamond wafer to be processed is adsorbed on the floating plate 402 by the porous ceramic suction cup 401 and fixed for the second time with a limit ring. The hollow spindle 316 is mounted with a cup-shaped ceramic-based diamond grinding wheel, and the floating plate 402 in the polishing plate assembly is in a locked state. Turn on the frameless motor in the hollow rotating spindle assembly 3 and increase the speed to a maximum speed of 1500r / min. Turn on the direct-drive rotating motor 406 and gradually increase the speed to 1350r / min. Run at no load for 5 minutes. After the device runs stably, feed the Z-axis feed device 1 downward until it contacts the diamond wafer. When the real-time downward pressure data is observed to rise from 0, stop the Z-axis feed. Set the Z-axis feed device 1 to automatic mode. At this time, the Z-axis feeds at a speed of 100 microns per hour. The X-axis reciprocating device 2 is turned on. At this time, the X-axis will mount the hollow spindle 316 to perform lateral reciprocating motion, and gradually increase the reciprocating speed to the working speed. After 3 hours of processing, the diamond wafer is removed by 300 microns. At this time, the surface roughness of the diamond wafer reaches Ra0.05 to Ra0.03.

[0050] After the first flattening step is complete, shut down the hollow spindle 316, the polishing disc assembly 4, and the X-axis reciprocating drive. Raise the Z-axis to the upper limit, replace the ceramic-based diamond grinding wheel with a resin-based diamond grinding wheel, gradually increase the speed of each axis to the operating speed, and press the Z-axis downward until the grinding wheel contacts the diamond wafer. After one hour of grinding in automatic mode, the removal volume should be 100 microns, and the surface roughness of the diamond wafer should reach approximately Ra0.01 to Ra0.005.

[0051] After the second flattening step is complete, repeat the above steps, replacing the resin-bonded diamond grinding wheel with a chemical reaction grinding wheel. Gradually increase the speed of each axis to the operating speed, and press the Z axis downward until the grinding wheel contacts the diamond wafer. After 0.5 hours of grinding in automatic mode, the removal volume should be 50 microns, and the theoretical roughness of the diamond surface should be reduced to Ra0.005 to Ra0.003.

[0052] After completing the flattening process stage, there is no need to disassemble the diamond wafer. First, release the limit of the floating disk 402 to put the floating device in operation. Lift the Z axis, replace the grinding wheel with the polishing pad 308 base, stick the polyurethane polishing pad 308, and enter the chemical mechanical polishing process. Turn on the shielded cavity protection exhaust system to reduce the harm to personnel caused by harmful gases or ultraviolet rays. Turn on the spindle positive pressure cavity heat dissipation system to prevent oxidizing gases from corroding the precision parts inside the hollow spindle 316. Turn on the waste liquid water circulation system to dilute and rinse the polishing waste liquid to reduce the corrosive effect of the oxidizing polishing waste liquid on the waste liquid pool 7 and other direct contact components. Press the hollow spindle 316 down until the static pressure reaches 199N. Set the Z-axis micro-feed device to the automatic polishing mode. The motor of the Z-axis feed device 1 will adjust the Z-axis height in real time according to the real-time feedback data of the positive pressure to maintain the preset positive pressure value. After the preparation work is completed, the polishing liquid supply system is first turned on to avoid dry friction between the polishing pad 308 and the diamond wafer, and the hollow spindle 316, the polishing disk rotating chassis 404, and the X-axis reciprocating device 2 are gradually turned on, and the operating speed is slowly increased to the working speed, that is, the polishing stage of the diamond wafer is officially started.

[0053] In this example, the oxidant used was a 12.5 g / 500 ml K2FeO4 solution, and the catalyst was composed of 4 g FeSO4 and 50 ml of a standard phosphoric acid solution dissolved in 200 ml of deionized water.

[0054] In this example, the polishing process involved three abrasive solutions. First, B4C abrasive, second only to diamond in hardness, was used for polishing. The solution consisted of 7g of 500nm B4C, 3g of 30nm Al2O3, and P25 TiO2 dissolved in 500ml of deionized water. The B4C was the primary abrasive, Al2O3 was the auxiliary abrasive, and TiO2 was the photocatalytic abrasive.

[0055] Secondly, the B4C abrasive is removed, and Al2O3 is used as the main abrasive and TiO2 as the photocatalytic abrasive and auxiliary abrasive.

[0056] Finally, the Al2O3 abrasive is removed, leaving only TiO2 with lower hardness as polishing abrasive.

[0057] The oxidant in this example can also be a 0.66 mol / L H2O2 solution, and the catalyst is composed of 50 ml of standard phosphoric acid solution dissolved in 200 ml of deionized water.

[0058] Polishing is first performed using B4C abrasive, which is second only to diamond in hardness. The solution consists of 7g of 500nm B4C, 3g of 30nm Al2O3, and P25 TiO2 dissolved in 500ml of deionized water. The B4C is the primary abrasive, the Al2O3 is the auxiliary abrasive, and the TiO2 is the photocatalytic abrasive.

[0059] Secondly, the B4C abrasive is removed, and Al2O3 is used as the main abrasive and TiO2 as the photocatalytic abrasive and auxiliary abrasive.

[0060] Finally, the Al2O3 abrasive is removed, leaving only TiO2 with lower hardness as polishing abrasive.

[0061] After 2 hours of polishing, under the action of H2O2, the surface roughness of the diamond wafer will quickly drop from Ra0.005 to Ra0.003 to Ra0.001 to Ra0.0005, and the material removal rate at this time can reach 150-200nm / h.

[0062] The photocatalytic removal mechanism in this embodiment is as follows: During the polishing process, an oxidizing polishing liquid is delivered to the diamond wafer via a hollow spindle 316. The liquid passes through a UV lamp 310 housed within a UV shield 311. Ultraviolet radiation then generates photogenerated electron / hole pairs on the surface of the TiO2 particles. These electron / hole pairs decompose water into highly oxidizing hydroxyl radicals (OH), which degrade organic matter. This creates a softened layer on the diamond surface, which is then mechanically removed using the relatively soft abrasives Al2O3 and B4C in the polishing liquid, resulting in a flat surface with a surface roughness of Ra 0.001 to Ra 0.0005.

[0063] After the grinding and polishing of the diamond wafer is completed, the Z-axis feed device 1 is raised to the upper limit, the spindle rotation, the polishing disc assembly 4, and the X-axis reciprocating device 2 are turned off, and the diamond wafer is rinsed with deionized water. The porous ceramic suction cup 401 air supply system is turned off, and the processed diamond wafer is taken out. The equipment will automatically return to zero position and wait for the next processing.

[0064] The device and method in this embodiment can effectively improve the grinding and polishing efficiency of diamond wafers, optimize the technical problem that traditional equipment is not suitable for diamond wafer processing, realize the rapid flattening processing of diamond wafers, and thus improve the processing accuracy of diamond wafers.

[0065] This embodiment also provides an apparatus for an integrated grinding and polishing method for diamond wafers, as shown in Figures 2, 3, 4 and 5, comprising: a base support; a marble platform 6 disposed above the base support and connected to the base; a waste liquid tank 7 disposed above the marble platform 6 and connected to the marble platform 6; a polishing disc assembly 4 disposed above the marble platform 6 and connected to the marble platform 6; a gantry disposed on one side above the marble platform 6, adjacent to the waste liquid tank 7, and connected to the marble platform 6; The X-axis reciprocating device 2 is arranged above the gantry and connected to the gantry; the Z-axis feeding device 1 is arranged above the X-axis reciprocating device 2 and connected to the X-axis reciprocating device 2; the hollow rotating spindle assembly 3 is arranged on the side of the Z-axis feeding device 1 and connected to the Z-axis feeding device 1; the human-computer interaction and control module 8 is arranged above the gantry and connected to the gantry, and is electrically connected to the X-axis reciprocating device 2 and the Z-axis feeding device 1; the polishing pad assembly is arranged at the bottom of the hollow rotating spindle assembly 3 and connected to the hollow rotating spindle assembly 3.

[0066] The apparatus used in this embodiment for the integrated grinding and polishing method of diamond wafers comprises a Z-axis feed mechanism 1, an X-axis reciprocating mechanism 2, a hollow rotating spindle assembly 3, a polishing disc assembly 4, a marble platform 6, a waste liquid tank 7, and a human-machine interaction and control module 8. The X-axis reciprocating mechanism 2 is bolted to the gantry beam of the marble platform 6 to enable lateral feeding of the grinding wheel; the Z-axis feed mechanism 1 is mounted on the motion platform of the X-axis reciprocating mechanism 2, thereby enabling the lifting and lowering motion of the grinding wheel. The hollow rotating spindle assembly 3 is vertically mounted to the motion platform of the Z-axis feed mechanism 1 via bolts. The marble platform 6 is provided with a stepped hole, and the polishing disc assembly 4 is bolted to the bottom of the stepped hole. The waste liquid tank 7 in this embodiment is a corrosion-resistant, integrated waste liquid tank 7, which is directly fixed to the marble platform 6 with long bolts and recovers waste liquid via a polishing liquid return pipe 9. The human-machine interaction and control module 8 is secured to the marble platform 6 via a cantilever bracket mounted on the top of the gantry of the marble platform 6. The diamond wafer is adsorbed on the top of the polishing disc assembly 4 by the porous ceramic suction cup 401 in the polishing disc assembly 4 and contacts the grinding wheel and polishing pad 308. This arrangement enables the diamond wafer to move in the Z-axis and X-axis directions, thereby improving the grinding and polishing accuracy of the diamond wafer and ensuring the recyclability of waste liquid. In addition, by providing a human-computer interaction and control module 8, the grinding and polishing of the diamond wafer are automated, thereby improving the grinding and polishing efficiency of the diamond wafer.

[0067] In a possible embodiment, as shown in Figures 2 and 3, the hollow rotating spindle assembly 3 includes: a frame 301, which is arranged on the side of the Z-axis feeding device 1 and is connected to the Z-axis feeding device 1; a hollow spindle 316, which is arranged on one side of the frame 301 and is connected to the frame 301; a rotating shell end cover 302, which is arranged above the rotating shell 314 and is connected to the rotating shell 314; a bearing fixed end cover 304, which is arranged below the rotating shell end cover 302 and is connected to the rotating shell end cover 302; a double-row angular contact ball bearing 303, which is arranged below the rotating shell end cover 302, And it is connected to the rotating shell end cover 302; the rotating shell 314 is arranged on the outside of the double-row angular contact ball bearing 303 and is connected to the double-row angular contact ball bearing 303; the frameless motor is arranged between the hollow main shaft 316 and the rotating shell 314 and is connected to the hollow main shaft 316; the main shaft end cover 313 is arranged at the bottom of the hollow main shaft 316 and is connected to the hollow main shaft 316; the storage tray 312 is arranged at the bottom of the main shaft end cover 313 and is connected to the main shaft end cover 313; the polishing liquid droplet tube 307 is arranged at the lower end of the storage tray 312 and is connected to the storage tray 312.

[0068] Illustratively, the hollow rotating spindle assembly 3 consists of a T-shaped frame 301, a rotating housing end cap 302, a non-standard double-row angular contact ball bearing 303, a bearing fixing end cap 304, a motor outer rotor 305, a motor inner stator 306, a polishing liquid dripping tube 307, a polishing pad base 309, a polishing pad 308, a UV lamp head 310, a UV shield 311, a storage tray 312, a spindle end cap 313, a rotating housing 314, a coaxial cooling fan 315, and a hollow spindle 316. The T-shaped frame 301 is connected to the Z-axis feed mechanism 1 via bolts, and the hollow spindle 316 is fixed to the upper T-shaped frame 301 with round nuts. Two non-standard double-row angular contact ball bearings 303 are press-fitted to the rotating housing end cap 302 and the rotating housing 314, respectively, via the bearing fixing end cap 304 using six bolts. The motor's inner stator 306 is mounted on the hollow spindle 316 using its original press-fit disc. The motor's outer rotor 305, which forms part of the stator, is installed on the rotating housing 314 using an interference fit to drive the hollow rotating spindle assembly 3 into rotation. The UV shield 311 is coaxially connected to the rotating housing 314 via bolts. The polishing pad base 309 is bolted to the bottom of the UV shield 311 for replacing the polishing pad 308. The spindle end cap 313 is mounted to the bottom of the hollow spindle 316 using six fixing bolts to secure the inner race of the non-standard double-row angular contact ball bearing 303, which is fixed to the rotating housing 314, to the hollow spindle 316. A storage tray 312 is bolted to the bottom of the spindle end cap 313. The polishing liquid drip tube 307 and UV lamp holder 310 are secured to the lower end of the tray 312 using nylon cable ties. The hollow spindle 316 is a hollow structure with an inner diameter of 50 to 200 mm. The hollow spindle 316 provides a routing space for the ultraviolet light source, polishing liquid supply, and spindle air supply in the ultraviolet shielding cavity. A shielding cover is installed inside the grinding wheel mounting seat.

[0069] For example, the integrated diamond grinding and polishing device of this embodiment incorporates a coaxial cooling fan 315 mounted within the hollow spindle 316. When the hollow spindle 316 is in operation, air enters through the heat dissipation holes in the upper end cap and is exhausted through the side vents. This draws air from the inside of the hollow spindle 316 and exhausts it laterally. This not only removes heat from the motor but also prevents oxidizing gases from entering the hollow spindle 316 cavity through the rotating seal, thereby preventing component damage caused by heat accumulation due to continuous operation.

[0070] For example, the rotation speed of the hollow rotating spindle is 20 to 1500 r / min, the rotation speed of the direct-drive rotating motor 406 is 20 to 2000 r / min, and a polishing pressure of 0 to 600 N can be applied to the polishing disc.

[0071] In a possible embodiment, as shown in Figures 2 and 3, the hollow rotating spindle assembly 3 also includes: a UV lamp head, which is arranged at the lower end of the placement tray 312 and connected to the placement tray 312; and a UV shielding cover 311, which is arranged below the rotating shell 314 and connected to the rotating shell 314.

[0072] For example, during use, the device achieves chemical mechanical removal of diamonds through ultraviolet-induced oxidation, improving the efficiency of chemical mechanical polishing at room temperature and avoiding the hazards to equipment and personnel caused by the volatilization of oxidizing agents during thermal chemical mechanical polishing. Furthermore, the UV lamp head 310 and the polishing liquid supply tube are inserted into the UV shielding cover 311. The cavity of the UV shielding cover 311 also provides operating space for the polishing liquid supply and installation of the UV lamp head 310.

[0073] In a possible embodiment, as shown in Figures 2 and 3, the polishing pad 308 assembly also includes: a polishing pad base 309, which is arranged below the ultraviolet shielding cover 311 and connected to the polishing pad base 309; and a polishing pad 308, which is arranged at the bottom of the polishing pad base 309 and connected to the polishing pad base 309.

[0074] Exemplarily, the polishing pad base 309 is mounted on the bottom of the UV shielding cover 311 by bolts for replacing the polishing pad 308 .

[0075] In a possible embodiment, as shown in Figures 2, 4 and 5, the polishing disc assembly 4 includes: a base, which is arranged above the marble platform 6 and connected to the marble platform 6; a direct-drive rotary motor 406, which is arranged above the base and connected to the base; a polishing disc rotating chassis 404, which is arranged above the direct-drive rotary motor 406 and connected to the direct-drive rotary motor 406; a cylindrical guide rail 403, which is arranged above the polishing disc rotating chassis 404 and connected to the polishing disc rotating chassis 404; a floating disc 402, which is arranged above the cylindrical guide rail 403 and connected to the polishing disc rotating chassis 404; The cylindrical guide rail 403 is connected to the floating disk 402, thereby limiting the movement of the floating disk 402; the magnetic levitation pillar 410 is arranged at the bottom of the floating disk 402 and connected to the floating disk 402, thereby providing magnetic levitation for the floating disk 402; the porous ceramic suction cup 401 is arranged above the floating disk 402 and connected to the floating disk 402; the air supply pipe 407 is passed through the interior of the direct-drive rotating motor 406 and the floating disk 402, and is connected to the porous ceramic suction cup 401; the high-speed air slip ring 411 is sleeved on the end of the air supply pipe 407 close to the porous ceramic suction cup 401, and is connected to the air supply pipe 407.

[0076] Illustratively, the polishing plate assembly 4 includes a base, a porous ceramic suction cup 401, a floating plate 402, a cylindrical guide rail 403, a polishing plate rotating chassis 404, a direct-drive rotary motor 406, an air supply pipe 407 for the porous ceramic suction cup 401, magnetic levitation pillars 410, an air supply pipe 407, and a high-speed air slip ring 411. The porous ceramic suction cup 401 is concentrically mounted on the floating plate 402 using six nylon bolts. A negative pressure air source is provided by the high-speed air slip ring 411 located at the center of rotation and the air supply pipe 407 for the porous ceramic suction cup 401. Four evenly spaced cylindrical guide rails 403 mounted on the bottom of the floating plate 402 cooperate with linear bearings mounted on the polishing plate rotating chassis 404. Eight magnetic levitation pillars 410 mounted on the bottom end of the floating plate 402 are equipped with neodymium magnets to provide magnetic levitation for the floating plate 402, thereby constraining its movement.

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A diamond wafer grinding and polishing integrated method, characterized in that: The specific steps of this method include: S1: Using the porous ceramic-based diamond grinding wheel on the hollow rotating spindle assembly, combined with the X-axis reciprocating device and the Z-axis feeding device, the diamond wafer adsorbed on the top of the polishing disc assembly is roughly ground to reduce the surface roughness of the diamond wafer to Ra0.05 to Ra0.03; S2: replacing the porous ceramic-based diamond grinding wheel on the hollow rotating spindle assembly with a resin-based diamond grinding wheel, and then performing the first fine grinding on the diamond wafer to reduce the surface roughness of the diamond wafer to Ra0.01 to Ra0.005; S3: replacing the resin-based diamond grinding wheel on the hollow rotating spindle assembly with a chemical reaction grinding wheel, and then performing a second fine grinding on the diamond wafer, reducing the surface roughness of the diamond wafer to Ra0.005 to Ra0.003, and then completing the grinding of the diamond wafer; S4: The human-machine interaction and control module controls the Z-axis feeding device to lift the hollow rotating spindle assembly, replaces the chemical reaction grinding wheel with a polishing pad assembly, adds diamond abrasive polishing liquid to the polishing liquid dripping tube in the hollow rotating spindle assembly, and then roughly polishes the diamond wafer to reduce the surface roughness of the diamond wafer to Ra0.002 to Ra0.001; S5: replacing the diamond abrasive polishing liquid in the polishing liquid dripping tube with an aluminum oxide abrasive polishing liquid, and then performing a first fine polishing on the diamond wafer to reduce the surface roughness of the diamond wafer to Ra0.001 to Ra0.0005; S6: replacing the aluminum oxide abrasive polishing liquid in the polishing liquid drop tube with titanium dioxide abrasive polishing liquid, and then performing a second fine polishing on the diamond wafer to remove the scratches and adsorbed matter remaining on the surface of the diamond wafer, thereby obtaining a diamond wafer.

2. The integrated grinding and polishing method for a diamond wafer according to claim 1, characterized in that: In step S4, the diamond abrasive polishing liquid includes an oxidant, a catalyst, an acid-base regulator and a diamond abrasive solution; In step S5, the aluminum oxide abrasive polishing liquid includes an oxidant, a catalyst, an acid-base regulator and an aluminum oxide abrasive solution; In step S6, the titanium dioxide abrasive polishing liquid includes an oxidant, a catalyst, an acid-base regulator and a titanium dioxide abrasive solution.

3. The integrated grinding and polishing method for a diamond wafer according to claim 2, characterized in that: The oxidant includes any one of a K2FeO4 solution or a H2O2 solution.

4. The integrated grinding and polishing method for a diamond wafer according to claim 2, characterized in that: The catalyst is FeSO4 solution.

5. The integrated grinding and polishing method for a diamond wafer according to claim 2, characterized in that: The acid-base regulator is a phosphoric acid standard solution.

6. A device for use in the integrated grinding and polishing method for diamond wafers as claimed in claim 1, characterized in that: include: Base bracket; A marble platform is disposed above the base support and connected to the base; A waste liquid pool is arranged above the marble platform and connected to the marble platform; A polishing disc assembly is arranged above the marble platform and connected to the marble platform; A gantry is arranged on one side above the marble platform, adjacent to the waste liquid pool, and connected to the marble platform; An X-axis reciprocating device is disposed above the gantry and connected to the gantry; A Z-axis feeding device is disposed above the X-axis reciprocating device and connected to the X-axis reciprocating device; A hollow rotating spindle assembly is arranged on the side of the Z-axis feeding device and connected to the Z-axis feeding device; A human-machine interaction and control module is arranged above the gantry and connected to the gantry, and is electrically connected to the X-axis reciprocating device and the Z-axis feeding device; The polishing pad assembly is arranged at the bottom of the hollow rotating main shaft assembly and connected to the hollow rotating main shaft assembly.

7. The device used in the integrated grinding and polishing method for diamond wafers according to claim 6, characterized in that: The hollow rotating spindle assembly comprises: A frame, arranged on the side of the Z-axis feeding device and connected to the Z-axis feeding device; A hollow main shaft is arranged on one side of the frame and connected to the frame; A rotating shell end cover is disposed above the rotating shell and connected to the rotating shell; A bearing fixed end cover is arranged below the rotating housing end cover and connected to the rotating housing end cover; Double row angular contact ball bearings are arranged below the end cover of the rotating housing and are connected to the rotating housing. The shell end covers are connected; A rotating housing is arranged on the outer side of the double-row angular contact ball bearing and connected to the double-row angular contact ball bearing; A frameless motor is disposed between the hollow main shaft and the rotating housing and connected to the hollow main shaft; A spindle end cover, disposed at the bottom of the hollow spindle and connected to the hollow spindle; A storage tray is arranged at the bottom of the spindle end cover and connected to the spindle end cover; A polishing liquid dripping tube is arranged at the lower end of the placing tray and connected to the placing tray.

8. The device used in the integrated grinding and polishing method for diamond wafers according to claim 7, characterized in that: The hollow rotating spindle assembly also includes: The ultraviolet lamp head is arranged at the lower end of the storage tray and connected to the storage tray; The ultraviolet shielding cover is arranged below the rotating shell and connected with the rotating shell.

9. The device used in the integrated grinding and polishing method for diamond wafers according to claim 8, characterized in that: The polishing pad assembly further comprises: A polishing pad base is disposed below the ultraviolet shielding cover and connected to the polishing pad base; The polishing pad is arranged at the bottom of the polishing pad base and connected to the polishing pad base.

10. The device used in the integrated grinding and polishing method for diamond wafers according to claim 6, characterized in that: The polishing disc assembly comprises: A base is arranged above the marble platform and connected to the marble platform; A direct-drive rotary motor is disposed above the base and connected to the base; A polishing disc rotating chassis is disposed above the direct-drive rotating motor and connected to the direct-drive rotating motor; A cylindrical guide rail is arranged above the polishing disc rotating chassis and connected to the polishing disc rotating chassis; A floating plate is disposed above the cylindrical guide rail and connected to the cylindrical guide rail, thereby limiting the movement of the floating plate through the cylindrical guide rail; A magnetic levitation support, disposed at the bottom of the floating disk and connected to the floating disk, thereby providing magnetic levitation force for the floating disk; A porous ceramic suction cup is arranged above the floating plate and connected to the floating plate; An air supply pipe is arranged inside the direct-drive rotary motor and the floating plate, and is connected to the porous ceramic suction cup; The high-speed air slip ring is sleeved on the end of the air supply pipe close to the porous ceramic suction cup and is connected to the air supply pipe.

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