Ceramic wedge knife micro-pore inner hole high-precision grinding method

Abstract

The application discloses a high-precision grinding method for a ceramic wedge micro-hole inner hole, which comprises the following steps: preliminary steps such as outer circle processing, length processing, ultrasonic micro-etching crack / oxidation layer removing, blank cleaning and drying, waste blank screening, mandrel processing and flexible clamping, four-stage grinding processing steps such as rough grinding, semi-precision grinding, resonance precision polishing and orifice passivation trimming, and post-processing steps such as cleaning and drying, multi-dimensional precision detection and qualified product judgment after processing. The high-precision grinding method for the ceramic wedge micro-hole inner hole adopts hierarchical substrate pretreatment, four-stage grinding technology of rough grinding-semi-precision grinding-resonance precision polishing-passivation trimming, matches differentiated diamond grinding medium, flexible mandrel grinding tool, axial micro-vibration+unidirectional rotation compound motion mode, and can better complete ceramic wedge 0.02-0.08mm micro-hole inner hole processing.

Description

Technical Field

[0001] This invention relates to the fields of precision machining of semiconductor packaging tools and ceramic micro-hole grinding technology, specifically to a high-precision grinding method for the inner hole of a ceramic cleaver. Background Technology

[0002] Ceramic wire cutters are core consumables in semiconductor gold wire bonding, copper wire bonding, and aluminum wire bonding packaging processes. They are mainly made of zirconia-toughened ceramic, which has the advantages of high hardness, wear resistance, good insulation, and low high-temperature deformation. The center of the wire cutter has a micron-level wire through hole. The inner hole size accuracy, hole wall smoothness, coaxiality, and hole integrity directly determine the smoothness of the bonding wire delivery, the bonding joint yield, and the service life of the wire cutter.

[0003] The existing process for machining the micro-holes of ceramic cleavers involves first pre-forming the inner hole using laser drilling / diamond micro-grinding, and then using a single-grit abrasive bar with conventional abrasive paste to complete the finishing of the inner hole. However, this process has many defects in actual production. (1) Ceramics are brittle and hard materials. After micro-hole drilling and grinding, a large number of longitudinal lines, sintering hidden cracks, and micro-chipping of the hole opening remain on the hole wall. Conventional grinding cannot completely remove them. During the bonding process, the wires wear and break, and generate debris that contaminates the solder joint. (2) The rigidity of the ultra-fine micro-pore (0.02~0.08mm) grinding mandrel is too large. During the grinding process, the rigid pressure of the ceramic hole wall is easily aggravated by brittle edge breakage and secondary micro cracks. At the same time, the taper error is formed at both ends of the inner hole, and the straightness and roundness exceed the standard. (3) The grinding process adopts a single rotation speed and vibration-free static grinding mode. The grinding media is unevenly distributed, the amount of material removed from the hole wall is inconsistent, and the coaxiality of the inner hole is poor, which cannot meet the ±1μm dimensional tolerance requirements of high-end semiconductor packaging. (4) The graded grinding particle size is not properly matched, the coarse grinding allowance is insufficient, the fine grinding and polishing efficiency is low, the mass production processing cycle is long, the finished product qualification rate is low, and the production cost is high.

[0004] Existing patents and industry processes mostly focus on the shape of the chopping tool and the grinding optimization of the outer conical surface. There is a lack of graded grinding processes that are suitable for micron-level ultrafine internal holes and brittle ceramic substrates. These processes cannot solve the problem of coordinated control of taper, roughness, edge chipping, and coaxiality of ultrafine internal holes. Therefore, the development of a special grinding method adapted to the micropores of ceramic chopping tools has great industrialization value. Summary of the Invention

[0005] The purpose of this invention is to address the problems of existing technologies, such as numerous scratches, large taper, poor roundness and coaxiality, edge chipping at the hole opening, residual hidden cracks, and low mass production yield, by providing a high-precision grinding method for the micro-hole inner hole of a ceramic cleaver.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for high-precision grinding of the micropore inner hole of a ceramic cleaver includes the following steps: Pre-treatment of ceramic chopping tool blanks: Select sintered dense chromium oxide ceramic chopping tool semi-finished products and complete the fine machining of the outer circle, conical surface and tool head shape; use ultrasonic micro-etching process to remove residual blank particle texture, sintered oxide layer and micro-cracks at the opening of the chopping tool inner hole; after cleaning and drying, inspect the initial hole diameter, straightness and edge chipping defects at the opening of the inner hole, and select qualified ceramic chopping tool blanks for use. Tooling clamping and positioning: The pre-treated ceramic chopping blank is fixed in a precision indexing tooling. An air-floating bushing clamp is used. When coaxially introducing the material, an ultra-fine grinding mandrel is inserted. The gap between the ultra-fine grinding mandrel and the inner hole of the chopping blank is controlled at 1 to 2 μm to adaptively complete the coaxial positioning. Graded grinding process: The inner hole of the cleaver is subjected to four processes in sequence: coarse grinding, semi-fine grinding, resonant fine polishing, and hole mouth passivation trimming. Post-processing inspection: After processing, clean the residual grinding debris and grinding paste from the inner hole of the chopping tool, and dry it with hot air at a constant temperature; perform full-dimensional inspection of the inner hole diameter, roundness, roughness, coaxiality and orifice integrity of the chopping tool to obtain the finished ceramic chopping tool.

[0007] This high-precision grinding method for the micro-hole inner hole of ceramic wedges can effectively solve the problems of numerous scratches, large taper, poor roundness and coaxiality, edge chipping at the hole opening, residual hidden cracks, and low mass production yield of existing ceramic wedges. It can realize ultra-precision machining and large-scale mass production of micro-hole inner holes of ceramic wedges for semiconductor packaging.

[0008] This high-precision grinding method for the micro-hole inner diameter of ceramic wedges employs a four-stage grinding process: graded substrate pretreatment, coarse grinding, semi-fine grinding, resonant fine polishing, and passivation trimming. It utilizes differentiated diamond grinding media, a flexible mandrel grinding fixture, and a composite motion mode of axial micro-vibration and unidirectional rotation, enabling it to effectively machine micro-holes ranging from 0.02 to 0.08 mm in ceramic wedges. Furthermore, the graded grinding process allows for fine finishing and inspection of the workpiece; any workpiece that fails to meet the standards is reworked, ensuring a high yield rate.

[0009] This method employs ultrasonic micro-etching pretreatment to eliminate the original cracks and oxide layer in the blank and grinding process in advance, reducing the source of defects in subsequent grinding processing. The accompanying flexible clamping fixture ensures the overall coaxial positioning accuracy, and significantly optimizes the coaxiality and roundness of the inner hole of the finished product.

[0010] The present invention, through the above-described method steps, can eliminate the taper of the inner hole of the ceramic wedge, micro-cracks and chipping of the cutting edge, with the inner hole roundness not exceeding 0.3μm, the roughness R not exceeding 0.02μm, and the coaxiality not exceeding 0.5μm, thus greatly improving the bonding stability and service life of the ceramic wedge.

[0011] In some embodiments, the ultrasonic micro-etching process includes: selecting a composite weak acid solution as the etching solution, an ultrasonic frequency of 35-40 kHz, a micro-etching time of 6-10 H, and a micro-etching temperature of 60-70 °C; the initial aperture of the inner hole of the cleaver is 0.02-0.08 mm, and the initial roughness Ra is 0.8-1.6 μm.

[0012] In some embodiments, the ultrafine grinding mandrel is a tungsten substrate coated with a flexible nano-polyurethane layer, and the diameter tolerance of the ultrafine grinding mandrel is ±0.1μm; the precision indexing fixture is equipped with a dual-drive module for bidirectional rotation and axial micro-vibration.

[0013] In some embodiments, the coarse grinding process is as follows: using 8000-mesh diamond petroleum-based grinding paste, the ultrafine grinding mandrel has no self-rotation and adapts to vibration and undulation, the ceramic chopping blank rotates in the opposite direction at a speed of 300-400 r / min, the axial micro-vibration frequency is 18-22 kHz and the amplitude is 3-5 μm, and the grinding time is 30-50 s; removing deep tool marks and macro-taperes in the inner hole of the chopping cutter, and controlling the roughness Ra of the inner hole of the chopping cutter to be reduced to 0.2-0.4 μm.

[0014] In some embodiments, the semi-fine grinding process includes: replacing the 15000-mesh diamond petroleum-based grinding paste; the ultrafine grinding mandrel does not rotate and adapts to vibration; reducing the rotational speed of the ceramic chopping blank; the reverse rotational speed of the ceramic chopping blank is 200-250 r / min; the axial micro-vibration frequency is 25-28 kHz; the amplitude is 1.5-2 μm; and the grinding time is 30-50 s; correcting the roundness and straightness deviation of the chopping blank inner hole; eliminating the micro-steps on the inner hole wall of the chopping blank; and reducing the roughness Ra of the inner hole of the chopping blank to 0.05-0.08 μm.

[0015] In some embodiments, the resonant polishing process includes: replacing the 30,000-mesh nano-diamond composite polishing fluid; adjusting the vibration frequency of the precision indexing tool to match the resonant frequency of the polishing fluid medium, which is 32–35 kHz; rotating the ceramic cleaver blank in the opposite direction at a low speed of 500–600 r / min; the ultrafine grinding mandrel having no self-rotation and adapting to vibration with its own undulations, with an axial micro-vibration amplitude of 0.6–1 μm; and polishing for 30–50 s; thus achieving atomic-level polishing of the inner hole and eliminating micro-stress and hidden cracks in the hole wall.

[0016] In the rough grinding, semi-fine grinding, and resonant fine polishing steps, a gradient grinding medium of 8000 grit → 15000 grit → 30000 grit is used sequentially to remove excess material, correct dimensional and positional tolerances, perform atomic-level polishing, and trim the hole edges in stages. This approach balances grinding efficiency and processing accuracy, increasing the mass production yield to over 96%. All three processes employ a composite motion of flexible coated grinding mandrel + workpiece rotation + mandrel adaptive undulation + axial frequency conversion micro-vibration, weakening the rigid grinding extrusion stress and completely avoiding secondary chipping and micro-cracks in brittle ceramic micropores. This method is suitable for machining ultra-fine holes of 0.02–0.08 mm.

[0017] In some embodiments, the process of passivating and trimming the orifice is as follows: using a nano-silica flexible polishing medium, low amplitude micro-vibration is used to trim the upper and lower ends of the inner hole of the wedge, the trimming time is 10-15s, the sharp edge and micro-chipping of the orifice are removed, and a smooth arc transition angle of R0.8-1.2μm is formed.

[0018] In some embodiments, the cleaning method in the post-processing detection step is as follows: acetone ultrasonic cleaning and anhydrous ethanol ultrasonic cleaning are performed sequentially, with acetone ultrasonic cleaning for 5 minutes and anhydrous ethanol ultrasonic cleaning for 8 minutes; the drying temperature after cleaning is 55-60°C.

[0019] Furthermore, the finished ceramic chopping tool has an inner hole roundness of ≤0.3μm, an inner hole roughness Ra of ≤0.02μm, and a coaxiality between the inner hole and the outer circle of the chopping tool of ≤0.5μm.

[0020] Furthermore, the raw materials for the semi-finished ceramic cleaver are chromium oxide ceramic and toughened zirconium oxide, with a Vickers hardness of 1900-2100 HV and a fracture toughness of not less than 8.2 MPa•m. 1 / 2 .

[0021] Compared with the prior art, the beneficial effects of this invention are: 1. This high-precision grinding method for the inner hole of micro-holes in ceramic wedges can effectively solve the problems of numerous scratches, large taper, poor roundness and coaxiality, edge chipping at the hole opening, residual hidden cracks, and low mass production yield in the existing ultra-fine inner hole grinding of ceramic wedges. It can realize ultra-precision machining and large-scale mass production of the inner hole of micro-holes in semiconductor packaging ceramic wedges; 2. This high-precision grinding method for the inner hole of micro-holes in ceramic wedges adopts a graded substrate pretreatment, a four-stage grinding process of coarse grinding - semi-fine grinding - resonant fine polishing - passivation trimming, matched with differentiated diamond grinding media, flexible mandrel grinding fixture, and axial micro-vibration + unidirectional rotation composite motion mode, which can better complete the machining of 0.02~0.08mm micro-holes in ceramic wedges; 3. This method uses ultrasonic micro-etching pretreatment to eliminate the original cracks and oxide layer in the blank and grinding in advance. This method reduces the source of defects in subsequent grinding processes. By adding a polishing fluid resonance polishing process, the uniform flow of nano-abrasives is enhanced by media resonance, achieving scratch-free ultra-smooth machining of the inner hole with an inner hole roughness Ra≤0.02μm and zero jamming and wear in wire feeding. 4. This method can eliminate the taper, micro-cracks and chipping of the inner hole of ceramic wedges, with the inner hole roundness not exceeding 0.3μm, roughness R not exceeding 0.02μm, and coaxiality not exceeding 0.5μm, significantly improving the bonding stability and service life of ceramic wedges. 5. In the steps of rough grinding, semi-fine grinding and resonance polishing, 8000 mesh → 15000 mesh → 30000 mesh gradient grinding media are matched sequentially to remove excess material, correct dimensional and positional tolerances, perform atomic-level polishing, and trim the hole opening step by step, balancing grinding efficiency and machining accuracy, and increasing the mass production yield to over 96%. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the process flow for a high-precision grinding method for the micropore inner hole of a ceramic chopping tool according to the present invention. Figure 2 A schematic diagram of the hole wall structure of a ceramic chopping tool processed by the high-precision grinding method of the present invention; Figure 3 for Figure 2 A magnified schematic diagram of the central part of the structure; Figure 4 A schematic diagram of the hole wall structure of a ceramic chopping tool processed using existing conventional processes; Figure 5 for Figure 4 A magnified schematic diagram of the central part of the structure. Detailed Implementation

[0023] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: A method for high-precision grinding of the micropore inner hole of a ceramic cleaver is provided, combined with... Figure 1 As shown, the process includes preliminary steps such as outer diameter machining, length machining, ultrasonic micro-etching to remove cracks / oxide layers, billet cleaning and drying, screening of waste billets, mandrel machining and flexible clamping, as well as four-stage grinding processes such as rough grinding, semi-fine grinding, resonant fine polishing and hole passivation trimming. After processing, subsequent steps such as cleaning and drying, multi-dimensional precision inspection and qualified product judgment are performed to achieve ultra-precision machining of the inner hole of the micro-hole of the semiconductor packaging ceramic cleaver.

[0025] The method specifically includes the following steps: Step 1: Pre-treatment of ceramic cleaver blanks: Select sintered dense chromium oxide ceramic cleaver semi-finished products and complete the fine machining of the outer circle, conical surface and cleaver head shape; use ultrasonic micro-etching process to remove residual blank particle texture, sintered oxide layer and micro-cracks at the hole opening of the cleaver; after cleaning and drying, check the initial hole diameter, straightness and edge chipping defects at the hole opening, and select qualified ceramic cleaver blanks for use. Step 2, Fixture clamping and positioning: Fix the pretreated ceramic chopping blank to the precision indexing fixture, using an air-floating bushing clamp, and insert an ultra-fine grinding mandrel during coaxial introduction. The gap between the ultra-fine grinding mandrel and the inner hole of the chopping blank is controlled at 1~2μm to adaptively complete coaxial positioning. Step 3, graded grinding process: The inner hole of the cleaver is subjected to four processes in sequence: rough grinding, semi-fine grinding, resonant fine polishing, and hole passivation trimming. Step 4, Post-processing and inspection: After processing, clean the residual grinding debris and grinding paste from the inner hole of the chopping tool, and dry it with hot air at a constant temperature; complete the full-dimensional inspection of the inner hole diameter, roundness, roughness, coaxiality and orifice integrity of the chopping tool to obtain the finished ceramic chopping tool.

[0026] This high-precision grinding method for the micro-hole inner hole of ceramic wedges can effectively solve the problems of numerous scratches, large taper, poor roundness and coaxiality, edge chipping at the hole opening, residual hidden cracks, and low mass production yield of existing ceramic wedges. It can realize ultra-precision machining and large-scale mass production of micro-hole inner holes of ceramic wedges for semiconductor packaging.

[0027] This high-precision grinding method for the micro-hole inner diameter of ceramic wedges employs a four-stage grinding process: graded substrate pretreatment, coarse grinding, semi-fine grinding, resonant fine polishing, and passivation trimming. It utilizes differentiated diamond grinding media, a flexible mandrel grinding fixture, and a composite motion mode of axial micro-vibration and unidirectional rotation, enabling it to effectively machine micro-holes ranging from 0.02 to 0.08 mm in ceramic wedges. Furthermore, the graded grinding process allows for fine finishing and inspection of the workpiece; any workpiece that fails to meet the standards is reworked, ensuring a high yield rate.

[0028] This method employs a pre-treatment ultrasonic micro-etching process to eliminate inherent cracks and oxide layers in the blank and during grinding, reducing the source of defects in subsequent grinding processes. A flexible clamping fixture ensures overall coaxial positioning accuracy, significantly optimizing the coaxiality and roundness of the finished inner hole. By adding a polishing fluid resonance polishing process, the uniform flow of nano-abrasives is enhanced through media resonance, achieving scratch-free, ultra-smooth machining of the inner hole with an inner hole roughness Ra≤0.02μm, and zero jamming and wear during wire feeding.

[0029] The present invention, through the above-described method steps, can eliminate the taper of the inner hole of the ceramic wedge, micro-cracks and chipping of the cutting edge, with the inner hole roundness not exceeding 0.3μm, the roughness R not exceeding 0.02μm, and the coaxiality not exceeding 0.5μm, thus greatly improving the bonding stability and service life of the ceramic wedge.

[0030] This method also has the advantage of precise and controllable process parameters, making it suitable for the mass production of zirconia ceramic cleavers for semiconductor packaging. It improves the bonding yield of finished cleavers by 8% to 12% and increases the tool life by more than 40%, making it suitable for the production needs of high-end chip gold wire and ultra-fine copper wire bonding.

[0031] In step 1, the ultrasonic micro-etching process includes: selecting a composite weak acid solution as the etching solution, an ultrasonic frequency of 35-40 kHz, a micro-etching time of 6-10 H, and a micro-etching temperature of 60-70 °C; the initial aperture of the inner hole of the cleaver is 0.02-0.08 mm, and the initial roughness Ra is 0.8-1.6 μm.

[0032] In step 2, the ultrafine grinding mandrel is a tungsten substrate coated with a flexible nano-polyurethane layer, and the diameter tolerance of the ultrafine grinding mandrel is ±0.1μm; the precision indexing fixture is equipped with a dual-drive module for bidirectional rotation and axial micro-vibration.

[0033] In step 3, the coarse grinding process is as follows: using 8000-mesh diamond petroleum-based grinding paste, the ultrafine grinding mandrel has no self-rotation and adapts to vibration and undulation, the ceramic chopping blank rotates in the opposite direction at a speed of 300-400 r / min, the axial micro-vibration frequency is 18-22 kHz and the amplitude is 3-5 μm, and the grinding time is 30-50 s; the deep tool marks and macro-taper of the chopping tool's inner hole are removed, and the roughness Ra of the chopping tool's inner hole is controlled to be reduced to 0.2-0.4 μm.

[0034] Further, in step 3, the semi-fine grinding process is as follows: replace the 15000-mesh diamond petroleum-based grinding paste, the ultrafine grinding mandrel does not rotate and adapts to vibration, reduce the rotation speed of the ceramic chopping blank, the reverse rotation speed of the ceramic chopping blank is 200-250 r / min, the axial micro-vibration frequency is 25-28 kHz, the amplitude is 1.5-2 μm, and the grinding time is 30-50 s; correct the roundness and straightness deviation of the chopping blank inner hole, eliminate the micro-steps on the inner hole wall of the chopping blank, and reduce the roughness Ra of the chopping blank inner hole to 0.05-0.08 μm.

[0035] Further, in step 3, the resonant polishing process is as follows: the 30,000-mesh nano-diamond composite polishing fluid is replaced, and the vibration frequency of the precision indexing tool is adjusted to match the resonant frequency of the polishing fluid medium, which is 32-35 kHz; the ceramic cleaver blank is rotated in the opposite direction at a low speed of 500-600 r / min, the ultrafine grinding mandrel does not rotate and adapts to the vibration, with an axial micro-vibration amplitude of 0.6-1 μm, and polishing is performed for 30-50 seconds; atomic-level polishing of the inner hole is achieved, eliminating micro-stress and hidden cracks in the hole wall.

[0036] In the rough grinding, semi-fine grinding, and resonant fine polishing steps, a gradient grinding medium of 8000 grit → 15000 grit → 30000 grit is used sequentially to remove excess material, correct dimensional and positional tolerances, perform atomic-level polishing, and trim the hole edges in stages. This approach balances grinding efficiency and processing accuracy, increasing the mass production yield to over 96%. All three processes employ a composite motion of flexible coated grinding mandrel + workpiece rotation + mandrel adaptive undulation + axial frequency conversion micro-vibration, weakening the rigid grinding extrusion stress and completely avoiding secondary chipping and micro-cracks in brittle ceramic micropores. This method is suitable for machining ultra-fine holes of 0.02–0.08 mm.

[0037] Furthermore, in step 3, the process of passivating and trimming the orifice is as follows: using a nano-silica flexible polishing medium, low amplitude micro-vibration is used to trim the upper and lower ends of the inner hole of the wedge, the trimming time is 10-15s, the sharp edge and micro-chipping of the orifice are removed, and a smooth arc transition angle of R0.8-1.2μm is formed.

[0038] In some embodiments, the cleaning method in the post-processing detection step is as follows: acetone ultrasonic cleaning and anhydrous ethanol ultrasonic cleaning are performed sequentially, with acetone ultrasonic cleaning for 5 minutes and anhydrous ethanol ultrasonic cleaning for 8 minutes; the drying temperature after cleaning is 55-60°C.

[0039] Furthermore, the finished ceramic chopping tool has an inner hole roundness of ≤0.3μm, an inner hole roughness Ra of ≤0.02μm, and a coaxiality between the inner hole and the outer circle of the chopping tool of ≤0.5μm.

[0040] Furthermore, the raw materials for the semi-finished ceramic cleaver are chromium oxide ceramic and toughened zirconium oxide, with a Vickers hardness of 1900-2100 HV and a fracture toughness of not less than 8.2 MPa•m. 1 / 2 .

[0041] Example 2: This example uses the machining of a 0.025mm diameter zirconia ceramic bonding wedge as an example to illustrate the high-precision grinding method for the micropore inner hole of this ceramic wedge.

[0042] The steps are as follows: a1. Blank pretreatment: Chromium oxide ceramic cleaver blank, pre-made with 0.020mm inner hole, initial roughness Ra1.2μm; 38kHz ultrasonic micro-etching for 1-2 hours to remove micro-cracks at the hole opening and oxide layer on the hole wall, followed by pure water cleaning and drying. a2. Tooling clamping: Flexible polyurethane-coated tungsten steel grinding mandrel, mandrel diameter 0.023mm, mandrel and inner hole clearance 2μm; self-adaptive fixture clamps the cleaver handle, tooling coaxial positioning accuracy 0.15μm; a3. Graded grinding: Rough grinding: 8000-mesh water-based diamond grinding paste, mandrel adaptive undulation, workpiece reverse rotation speed 350r / min, 20kHz vibration, amplitude 4μm, grinding for 10S; Semi-finish grinding: 15000 mesh oil-based grinding paste, mandrel self-adaptive to undulations, workpiece speed 220r / min, 26kHz vibration, amplitude 1.8μm, grinding for 15 seconds; Resonance polishing: 30,000 mesh nano diamond polishing slurry, 34kHz resonant frequency, mandrel adaptive undulation, workpiece reverse low-speed rotation 500-600 r / min, amplitude 0.8 μm, polishing 2 seconds; Orifice trimming: trimming with nano-silica medium for 6 min, orifice radius R1.0μm; a4. Post-treatment: Acetone ultrasonic cleaning for 5 min, ethanol ultrasonic cleaning for 8 min, and hot air drying at 58℃; the finished product is tested to have a pore diameter of 0.05 mm, roundness of 0.22 μm, roughness Ra of 0.02 μm, coaxiality of 0.4 μm, and no chipping or cracking defects.

[0043] The above steps can produce qualified zirconia ceramic bonding wedges with a pore size of 0.025mm, and the dimensional accuracy and tolerance meet the preset requirements.

[0044] Example 3: This example provides a high-precision grinding method for the inner hole of a ceramic wedge. It processes a zirconia ceramic wedge with a hole diameter of 0.058mm. The process parameters are matched and the hole diameter is enlarged and optimized. The final product has an inner hole roundness of 0.28μm, a roughness Ra of 0.02μm, and a coaxiality of 0.45μm, which meets the industrial mass production standard.

[0045] Comparative example: A ceramic wedge of the same specification was processed using a conventional single grinding rod, 20,000-mesh mixed grinding paste, and unidirectional rotational vibration-free grinding process. The finished product had an inner hole roughness of Ra0.2μm, roundness of 1.2μm, coaxiality of 1.8μm, longitudinal scratches on the hole wall, and slight chipping at the hole opening. The finished product qualification rate was 62%.

[0046] Combination Figures 2-5 As shown, the ceramic chopping tool was cut open for testing, and the scratches on the hole wall were observed under a microscope. The ceramic chopping tool processed by conventional processes had scratches on the inner hole wall with a roughness Ra of 0.11 to 0.25 μm; while the ceramic chopping tool processed by the method of the present invention had no obvious marks on the hole wall, with Ra < 0.02 μm.

[0047] By comparing Examples 2 and 3 with the comparative examples, it can be seen that the high-precision grinding method for the micropore inner hole of the ceramic wedge is far superior to conventional industry processes in terms of product quality control, dimensional accuracy control, and product qualification rate, achieving significant progress.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for high-precision grinding of the micropore inner hole of a ceramic cleaver, characterized in that, Includes the following steps: Pre-treatment of ceramic chopping tool blanks: Select sintered dense chromium oxide ceramic chopping tool semi-finished products and complete the fine machining of the outer circle, conical surface and tool head shape; use ultrasonic micro-etching process to remove residual blank particle texture, sintered oxide layer and micro-cracks at the opening of the chopping tool inner hole; after cleaning and drying, inspect the initial hole diameter, straightness and edge chipping defects at the opening of the inner hole, and select qualified ceramic chopping tool blanks for use. Tooling clamping and positioning: The pre-treated ceramic chopping blank is fixed in a precision indexing tooling. An air-floating bushing clamp is used. When coaxially introducing the material, an ultra-fine grinding mandrel is inserted. The gap between the ultra-fine grinding mandrel and the inner hole of the chopping blank is controlled at 1 to 2 μm to adaptively complete the coaxial positioning. Graded grinding process: The inner hole of the cleaver is subjected to four processes in sequence: rough grinding, semi-fine grinding, resonant fine polishing, and hole mouth passivation trimming. Post-processing inspection: After processing, clean the residual grinding debris and grinding paste from the inner hole of the chopping tool, and dry it with hot air at a constant temperature; perform full-dimensional inspection of the inner hole diameter, roundness, roughness, coaxiality and orifice integrity of the chopping tool to obtain the finished ceramic chopping tool.

2. The method for high-precision grinding of the micropore inner hole of a ceramic cleaver according to claim 1, characterized in that, The ultrasonic micro-etching process includes: selecting a composite weak acid solution as the etching solution, an ultrasonic frequency of 35-40kHz, a micro-etching time of 6-10H, and a micro-etching temperature of 60-70℃; the initial aperture of the inner hole of the cleaver is 0.02-0.08mm, and the initial roughness Ra is 0.8-1.6μm.

3. The method for high-precision grinding of the micropore inner hole of a ceramic cleaver according to claim 1, characterized in that, The ultrafine grinding mandrel is a tungsten substrate coated with a flexible nano-polyurethane layer, and the diameter tolerance of the ultrafine grinding mandrel is ±0.1μm; the precision indexing fixture is equipped with a dual-drive module for bidirectional rotation and axial micro-vibration.

4. The method for high-precision grinding of the micropore inner hole of a ceramic cleaver according to claim 1, characterized in that, The coarse grinding process is as follows: using 8000-mesh diamond petroleum-based grinding paste, the ultrafine grinding mandrel has no self-rotation and adapts to vibration and undulation, the ceramic chopping blank rotates in the opposite direction at a speed of 300-400 r / min, the axial micro-vibration frequency is 18-22 kHz and the amplitude is 3-5 μm, and the grinding time is 30-50 s; the deep tool marks and macro-taper of the chopping tool's inner hole are removed, and the roughness Ra of the chopping tool's inner hole is controlled to be reduced to 0.2-0.4 μm.

5. The method for high-precision grinding of the micropore inner hole of a ceramic cleaver according to claim 1, characterized in that, The semi-fine grinding process is as follows: replace the 15000-mesh diamond petroleum-based grinding paste; the ultra-fine grinding mandrel does not rotate and adapts to vibration; reduce the rotation speed of the ceramic chopping blank; the reverse rotation speed of the ceramic chopping blank is 200-250 r / min; the axial micro-vibration frequency is 25-28 kHz and the amplitude is 1.5-2 μm; the grinding time is 30-50 s; correct the roundness and straightness deviation of the chopping blank inner hole; eliminate the micro-steps on the inner hole wall of the chopping blank; and reduce the roughness Ra of the chopping blank inner hole to 0.05-0.08 μm.

6. The method for high-precision grinding of the micropore inner hole of a ceramic cleaver according to claim 1, characterized in that, The resonant polishing process is as follows: replace the 30,000-mesh nano-diamond composite polishing fluid, adjust the vibration frequency of the precision indexing tool to match the resonant frequency of the polishing fluid medium, which is 32-35kHz; the ceramic chopping blank rotates in the opposite direction at a low speed of 500-600r / min, the ultrafine grinding mandrel does not rotate and adapts to the vibration, with an axial micro-vibration amplitude of 0.6-1μm, and polishing for 30-50s.

7. The method for high-precision grinding of the micropore inner hole of a ceramic cleaver according to claim 1, characterized in that, The process of passivating and trimming the orifice is as follows: using a nano-silica flexible polishing medium, low amplitude micro-vibration is used to trim the upper and lower ends of the inner hole of the wedge, the trimming time is 10-15s, the sharp edge and micro-chipping of the orifice are removed, and a smooth arc transition angle of R0.8-1.2μm is formed.

8. The method for high-precision grinding of the micropore inner hole of a ceramic cleaver according to claim 1, characterized in that, The cleaning method in the post-processing detection step is as follows: acetone ultrasonic cleaning and anhydrous ethanol ultrasonic cleaning are performed sequentially, with acetone ultrasonic cleaning for 5 minutes and anhydrous ethanol ultrasonic cleaning for 8 minutes; the drying temperature after cleaning is 55-60℃.

9. The method for high-precision grinding of the micropore inner hole of a ceramic cleaver according to claim 1, characterized in that, The finished ceramic chopping tool has an inner hole roundness of ≤0.3μm, an inner hole roughness Ra of ≤0.02μm, and a coaxiality between the inner hole and the outer circle of the chopping tool of ≤0.5μm.

10. The method for high-precision grinding of the micropore inner hole of a ceramic cleaver according to claim 1, characterized in that, The raw materials for the semi-finished ceramic cleaver are chromium oxide ceramic and toughened zirconium oxide, with a Vickers hardness of 1900-2100 HV and a fracture toughness of not less than 8.2 MPa•m. 1 / 2 .

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