A high-hardness diamond scribing soft knife and its preparation method

Abstract

The present invention discloses a high-hardness diamond scribing soft knife and a preparation method thereof, relating to the technical field of scribing knives, and comprising the following steps: S1: Slurry preparation: uniformly mixing solid fine powder and an organic carrier, and performing homogenization treatment to obtain a metal-diamond slurry; S2: Green body printing: uniformly coating the metal-diamond slurry on a wire mesh plate and then performing green body printing on a separator plate, and drying with hot air to obtain a diamond scribing knife green body; S3: Diffusion sintering and forming: putting the diamond scribing knife green body into a vacuum sintering furnace to successively perform diffusion sintering and isostatic pressing treatment after cooling to obtain a rough diamond scribing knife; S4: Pattern processing: successively performing film pasting, exposure, and etching treatment on the rough diamond scribing knife, and measuring the size after film stripping processing to obtain the diamond scribing soft knife.

Description

Technical Field

[0001] The present invention relates to the technical field of dicing blades, and specifically to a high-hardness diamond dicing soft blade and a preparation method thereof. Background Art

[0002] With the rapid development of China's semiconductor industry in recent years, the demand for dicing blades for dicing and slicing semiconductor wafers, ceramics, etc. has also increased accordingly. As a super-hard tool material, diamond has been used in the field of chip processing for more than a hundred years. Diamond dicing blades use the high hardness, wear resistance and good thermal conductivity of diamond for cutting, and have good applications in cutting a series of highly brittle materials such as silicon wafers, ceramics, and glass in the semiconductor industry.

[0003] According to the classification of the bonding method of diamond dicing blade materials, it is divided into three types of soft blades: metal dicing blades, resin dicing blades, and electroformed dicing blades. Among them, the resin dicing blade has limited cutting ability compared with metal and electroformed dicing blades, is suitable for light cutting and scraping, and has relatively poor wear resistance and short service life; the electroformed dicing blade can meet the application scenarios with higher cutting accuracy, but its production requires the use of advanced electroforming technology, and has high requirements for production equipment and processes, so the technical threshold is high; while the metal dicing blade has strong cutting ability, and due to the characteristics of the preparation material, it has a long service life and can still maintain good cutting effect after multiple uses. However, due to its traditional preparation process generally using hot pressing and casting to prepare the blank, the long cycle of post-treatment and the preparation yield make its manufacturing cost high;

[0004] At present, the preparation process of metal dicing soft blades is relatively complex, due to a series of high-cost equipment brought about by its sintering process and post-treatment precision control. In summary, a relatively simple preparation method of metal diamond dicing soft blades needs to be developed urgently. In summary, to solve the above problems, it is of great significance to provide a high-hardness diamond dicing soft blade and a preparation method thereof. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-hardness diamond dicing soft blade and a preparation method thereof to solve the problems raised in the prior art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A preparation method of a high-hardness diamond dicing soft blade, comprising the following steps:

[0008] S1: Slurry preparation: Mix solid micro-powder and organic carrier evenly and perform homogenization treatment to obtain a metal-diamond slurry;

[0009] S2: Green body printing: Uniformly coat the metal-diamond slurry on the wire mesh plate and then perform green body printing on the separator plate, followed by hot air drying to obtain the diamond scribing tool green body.

[0010] S3: Diffusion sintering and forming: Place the diamond scribing tool green body into a vacuum sintering furnace and perform diffusion sintering and isostatic pressing after cooling in sequence to obtain the rough diamond scribing tool.

[0011] S4: Graphic processing: Perform film pasting, exposure, and etching on the rough diamond scribing tool in sequence, and measure the size after film stripping to obtain the diamond scribing soft tool.

[0012] Preferably, the metal-diamond slurry comprises the following raw materials by mass fraction: 75 - 85 parts of solid micro-powder and 15 - 25 parts of organic carrier.

[0013] Among them, in step S3, the heating rate of the vacuum sintering furnace is 5 - 10 °C / min, and the sintering vacuum degree ≤ 0.01 Pa; during the diffusion sintering process: the diffusion sintering temperature is 650 - 900 °C, and the time is 30 - 120 min; during the isostatic pressing process, the isostatic pressing pressure is 10 - 50 Mpa, and the time is 10 - 60 min.

[0014] Among them, in step S1: during the homogenization process, the homogenization rotation speed is 800 - 2000 r / min, and the time is 30 - 120 min; in step S2: during the green body printing process, the printing is automatic printing, and the printing speed is 5 - 10 mm / s; during the hot air drying process: the drying temperature is 50 - 80 °C, and the time is 5 - 15 min.

[0015] Preferably, in step S4, the size of the tool exposure mask film is an inner diameter of 40.0 - 42.0 mm, an outer diameter of 58.0 - 60.0 mm, a circular ring, and a toothed circular ring with an inner diameter of 40.0 - 42.0 mm and an outer diameter of 58.0 - 60.0 mm.

[0016] Preferably, the solid micro-powder comprises the following substances by mass fraction: 10 - 20% diamond micro-powder, 80 - 85% oxygen-free copper powder, 1 - 3% tin powder, 3 - 5% silver powder; the particle size of the diamond micro-powder is 10 - 20 μm, the particle size of the oxygen-free copper powder is 1 - 3 μm, the particle size of the tin powder is 1 - 5 μm, and the particle size of the silver powder is 1 - 3 μm.

[0017] Preferably, the organic carrier comprises one or more of ethylene glycol, n-butanol, and terpineol.

[0018] Preferably, the diamond micro-powder is pre-modified, including the following steps:

[0019] (1) After rinsing the diamond powder clean with deionized water, immerse it in anhydrous ethanol at 40 - 45 °C for 10 - 15 min, take it out and add etching powder with a mass ratio of 1:0.5 - 0.7 to the diamond powder, transfer it to a homogenizer for homogenization treatment to obtain a mixture.

[0020] (2) Transfer the mixture to a muffle furnace, keep it at 450 - 500 °C for 5 - 10 min, then gradually heat it up to 600 - 650 °C at a rate of 5 - 10 °C / min, keep it at this temperature for 5 - 10 min, cool it with the furnace, remove impurities, and rinse it with deionized water to obtain pretreated diamond.

[0021] (3) Mix the pretreated diamond and nano - silicon powder evenly with a mass ratio of 1:0.8 - 1, conduct homogenization treatment, add them to a graphite mold pre - coated with hexagonal boron nitride dispersion liquid, and perform spark plasma sintering at 2 - 3 Mpa and 1080 - 1120 °C for 30 - 45 min to obtain modified diamond.

[0022] Among them, the mixture includes diamond powder and etching powder with a mass ratio of 1:0.5 - 0.7; the etching powder includes the following raw materials in parts by mass: 90 - 100 parts of nano - aluminum oxide, 2 - 3 parts of potassium chlorate, 2 - 3 parts of sodium perchlorate, 5 - 8 parts of nano - titanium powder, 10 - 15 parts of iron oxide powder; the modified diamond includes pretreated diamond and nano - silicon powder with a mass ratio of 1:0.8 - 1.

[0023] More preferably, the metal - diamond slurry further includes a dispersant, which is composed of the following raw materials in parts by mass: 20 - 25 parts of modified polyethylene glycol, 5 - 10 parts of polyvinyl alcohol, 2 - 3 parts of sodium dodecylbenzenesulfonate, 1 - 2 parts of polydimethylsiloxane, 60 - 70 parts of deionized water.

[0024] Among them, the preparation method of the modified polyethylene glycol includes the following steps:

[0025] (1) Mix acrylic acid and polyethylene glycol with a mass ratio of 1:4 - 4.2 and add them to a flask, add 2 - 3 wt% of p - toluenesulfonic acid and 240 - 260 ppm of phenothiazine based on the total mass after mixing, reflux and react at 110 - 120 °C for 6 - 7 h, and purify to obtain substance A.

[0026] (2) Add substance A to deionized water and stir evenly, add a mercapto - silane coupling agent with a mass ratio of 1:0.2 - 0.25 to substance A and 1 - 3 wt% of an initiator based on the total mass of substance A and the mercapto - silane coupling agent, stir at 45 - 55 °C for 2 - 3 h under ultraviolet light irradiation conditions to obtain modified polyethylene glycol.

[0027] More preferably, the molecular weight of the polyethylene glycol is 1000 - 2000, and the initiator is benzoin dimethyl ether.

[0028] Compared with the prior art, the beneficial effects of the present application are as follows:

[0029] (1) In the preparation method of a metal diamond scribing soft knife disclosed in the present invention, by the method of printing to prepare the diamond tool blank, the forming thickness of the diamond tool can be effectively controlled. Compared with the traditional processes of cold pressing followed by sintering and post-treatment of melting and casting, the preparation process is simple and the cost is low. Moreover, diffusion sintering can effectively weld the copper powder particles. Compared with the relatively low sintering temperature of the melting and casting method, the energy consumption is reduced. The diamond soft knife prepared by its unique preparation process has a thickness of only 100 - 150 μm, ensuring good processing accuracy, and having characteristics such as strong cutting ability, high hardness and wear resistance, long service life, and short preparation cycle, which is suitable for mass production, effectively solving the difficult problems such as long preparation process cycle and high cost of the metal diamond scribing soft knife.

[0030] (2) Since even at 1400 °C, the contact angle between diamond and copper is still as high as 128°, that is, the affinity is very low, and diamond and copper do not form chemical bonds, and the bonding method only adopts mechanical bonding, which easily leads to problems such as many voids and poor bonding force on the bonding surface, reducing the wear resistance of diamond scribing. The present invention first roughens the surface of the diamond to increase the contact area and friction, improving the mechanical locking effect, thereby improving the interfacial bonding force, hardness and durability; the present invention also performs silicon plating on the surface of the diamond. Silicon can react with the carbon on the surface of the diamond to form a carbon-silicon layer, which has a strong bonding property with the diamond, can prevent the diamond from contacting with oxygen in the air and being oxidized, and also inhibits the possibility of diamond graphitization at high temperatures. Moreover, silicon and copper can also react to form chemical bonds, greatly improving the bonding property between the diamond and the base material copper, and improving the wear resistance and hardness of the diamond scribing.

[0031] (3) During the process of roughening the surface of the diamond in the present invention, nano-titanium powder is introduced into the etching powder. Part of the titanium powder will first be oxidized by the oxygen generated by sodium perchlorate to form titanium dioxide, forming a thin film to locally cover the surface of the diamond, which can reduce excessive etching of the diamond surface, affecting the diamond structure and reducing stability. As the temperature further increases, part of the carbon on the diamond surface is oxidized and etched, and the exposed active carbon atoms will form titanium carbide with the remaining titanium, which can reduce further etching. At the same time, during the subsequent silicon plating, carbon-titanium-oxygen-silicon bonds can be formed, further improving the bonding property and stability. Moreover, the locally covered titanium dioxide on the surface can also act as a catalyst for the formation of carbon-silicon bonds, reducing the silicon plating temperature and reducing the impact on the diamond strength.

[0032] (4) In the metal-diamond slurry of the present invention, a dispersant containing modified polyethylene glycol is added. The polyethylene glycol molecular chain can form a protective film on the particle surface, preventing the direct contact and agglomeration of particles through steric hindrance effect. By grafting siloxane, it helps to bind the silicon-coated diamond, enabling it to be evenly dispersed in the slurry and improving the hardness and wear resistance of the subsequent material. Description of the Drawings

[0033] Figure 1 It is a schematic diagram of the preparation process of the present invention;

[0034] Figure 2 It is an example diagram of the mask exposure film design;

[0035] Figure 3 It is an example diagram of the completion of the green body printing in Example 1;

[0036] Figure 4 It is an example diagram of the sample after diffusion sintering and forming in Example 1;

[0037] Figure 5 It is an example diagram of the cross-sectional morphology of the sample after etching in Example 1;

[0038] Figure 6 It is an example diagram of the appearance after the stripping process in Example 1; Detailed Embodiment

[0039] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] It should be noted that there are no special restrictions on the purchasing manufacturers of all raw materials involved in the present invention. Exemplarily, it includes: in the following embodiments, parts are parts by mass, and all raw materials are commercially available. The particle size of the diamond micropowder is 10 - 20 μm, the particle size of the oxygen-free copper powder is 1 - 3 μm, the particle size of the tin powder is 1 - 5 μm, and the particle size of the silver powder is 1 - 3 μm; the model of the nano-aluminum oxide is ZTL-WAO-01, provided by Yangzhou Zhongtianli New Materials Co., Ltd.; the particle size of the nano-titanium powder is 40 - 50 nm; the particle size of the iron oxide powder is 50 nm; the model of the nano-silicon powder is YM-Si.

[0041] The implementation process of the preparation of a metal diamond scribing soft knife is as Figure 1 shown; the specific embodiments are as follows:

[0042] Example 1: Preparation of a metal diamond scribing soft knife:

[0043] S1: Slurry preparation: Mix the solid micropowder and the organic carrier evenly and perform homogenization treatment to obtain a metal-diamond slurry, specifically as follows:

[0044] A) Weigh precisely 34.8 g of diamond micropowder, 359.5 g of oxygen-free copper powder, 7.5 g of tin powder, and 15.8 g of silver powder respectively, and load them into a ball-milling and mixing tank. Mix at a rotational speed of 120 rpm / min for 30 min to obtain solid micropowder.

[0045] B) Weigh 104.4 g of ethylene glycol and gradually add it to the solid micropowder obtained in step A after mixing. Manually stir evenly first and then put it into a homogenizer. Homogenize at a rotational speed of 1200 r / min for 40 min to obtain metal-diamond slurry.

[0046] S2: Green body printing: Uniformly coat the metal-diamond slurry on a wire mesh screen and then perform green body printing on a separator board, followed by hot air drying to obtain a diamond scribing tool green body, specifically as follows:

[0047] C) Select a steel film screen with a thickness of 200 μm, and for the screen tool pattern size, select a circular pattern with an outer diameter of 100.0 mm.

[0048] D) Attach a boron nitride high-temperature separator board to the printing area of an automatic printer, install a 200-μm-thick steel film screen, uniformly coat the slurry on the area of the screen to be printed, and use a squeegee to automatically print at a speed of 5 mm / s to obtain a green body.

[0049] E) Put the green body completed in the above step D into a hot air oven and dry it at 80 °C for 10 min to obtain a diamond scribing tool green body, as shown in the product Figure 3 shown;

[0050] S3: Diffusion sintering and forming: Put the diamond scribing tool green body into a vacuum sintering furnace and perform diffusion sintering and isostatic pressing treatment after cooling in sequence to obtain a rough diamond scribing tool, specifically as follows:

[0051] F) Take the diamond scribing tool green body dried in the above step E and place it in a vacuum brazing furnace for diffusion sintering. Heat it at a heating rate of 10 °C / min to 750 °C, hold for 120 min, and the vacuum degree of the vacuum sintering furnace cavity is 1.2×10 -3 Pa, and cool it with the furnace for standby;

[0052] G) After sintering and forming, put the sample into an isostatic press for cold pressing. The isostatic pressing load is 30 MPa, and the holding time is 20 min; obtain a rough diamond scribing tool;

[0053] S4: Pattern processing: Perform film pasting, exposure, and etching on the rough diamond scribing tool in sequence, and measure the dimensions after stripping the film to obtain a diamond scribing soft tool, specifically as follows:

[0054] H) The rough diamond scribing tool completed by cold pressing in the above step G is subjected to pre-graphical treatment. The surface is leveled by a 1200# polishing machine, and then a series of processes such as film sticking - exposure - development - copper etching are used for graphical treatment;

[0055] I) After etching, the sample is stripped with a sodium hydroxide solution with a mass fraction of 4%, the solution temperature is 43 °C, the soaking time is 5 min, washed with pure water, and dried to obtain a soft diamond scribing tool. The actual measured size is 57.86 mm (O.D) X 40.09 mm (I.D), and the average thickness is 0.142 mm.

[0056] Example 2 The specific process for preparing a metal diamond soft scribing tool is as follows:

[0057] S1: Slurry preparation: The solid micro-powder and the organic carrier are mixed evenly and homogenized to obtain a metal - diamond slurry, specifically as follows:

[0058] A) Accurately weigh 35.2 g of diamond micro-powder, 360.5 g of oxygen-free copper powder, 7.2 g of tin powder, and 16.3 g of silver powder, and load them into a ball mill mixing tank respectively. Mix at a rotation speed of 120 rpm / min for 30 min to obtain solid micro-powder;

[0059] B) Weigh 111.5 g of ethylene glycol and gradually add it to the solid micro-powder completed in step A. After manual preliminary stirring, put it into a homogenizer and homogenize at a rotation speed of 1200 r / min for 40 min to obtain a metal - diamond slurry;

[0060] S2: Green body printing: The metal - diamond slurry is evenly coated on a wire mesh plate and then printed on a separator plate to form a green body, and then dried with hot air to obtain a diamond scribing tool green body, specifically as follows:

[0061] C) Select a steel film mesh plate with a thickness of 200 μm, and the pattern size of the mesh plate tool is a circular pattern with an outer diameter of 100.0 mm;

[0062] D) Adhere a boron nitride high-temperature separator plate to the printing area of an automatic printing machine, install a 200-μm-thick steel film mesh plate, evenly coat the slurry on the area to be printed on the mesh plate, and the squeegee automatically prints at a speed of 5 mm / s to obtain a green body;

[0063] E) Put the green body completed in the above step D into a hot air oven and dry it with hot air at 80 °C for 10 min to obtain a diamond scribing tool green body;

[0064] S3: Diffusion sintering and forming: Put the diamond scribing tool green body into a vacuum sintering furnace and perform diffusion sintering and isostatic pressing treatment after cooling in sequence to obtain a rough diamond scribing tool, specifically as follows:

[0065] F) Take the diamond scribing tool blank dried in the above step E and place it in a vacuum brazing furnace for diffusion sintering. Heat it at a heating rate of 10 °C / min to 750 °C, hold for 120 min, and the vacuum degree of the vacuum sintering furnace chamber is 1.1×10 -3 Pa, and cool it in the furnace for standby;

[0066] G) After sintering and forming, put the sample into an isostatic press for cold pressing. The isostatic pressing load is 30 MPa and the holding time is 20 min; obtain the rough diamond scribing tool;

[0067] S4: Graphic processing: Perform film pasting, exposure, and etching on the rough diamond scribing tool in sequence, measure the size after stripping process, and obtain the diamond scribing soft tool, specifically as follows:

[0068] H) Perform graphic pretreatment on the rough diamond scribing tool completed in cold pressing in the above step G. The surface is leveled by a 1200# polishing machine, and then a series of processes such as film pasting - exposure - developing - copper etching are used for graphic processing;

[0069] I) After etching, the sample is stripped with a 4% sodium hydroxide solution by mass fraction, the solution temperature is 45 °C, the soaking time is 5 min, washed with pure water, and dried to obtain the diamond scribing soft tool. The actual measured size is 57.35 mm (O.D) X 39.82 mm (I.D), and the average thickness is 0.135 mm.

[0070] Example 3: Modify the diamond, perform silicon plating treatment in advance, and add a dispersant to the metal - diamond slurry. The remaining processes are the same as those in Example 2:

[0071] Preparation of silicon - plated diamond: Mix 35.2 g of diamond particles and nano - silicon powder evenly at a mass ratio of 1:0.8, perform homogenization treatment, add them to a graphite mold pre - coated with a layer of hexagonal boron nitride dispersion liquid, and sinter by spark plasma sintering at 2.5 Mpa and 1100 °C for 30 min to obtain modified diamond;

[0072] The metal - diamond slurry also includes 18.27 g of dispersant, which includes the following raw materials by mass fraction: 23 parts of modified polyethylene glycol, 7 parts of polyvinyl alcohol, 2.5 parts of sodium dodecyl benzene sulfonate, 1.5 parts of polydimethylsiloxane, and 65 parts of deionized water;

[0073] Among them, the preparation method of modified polyethylene glycol includes the following steps: (1) Mix acrylic acid and polyethylene glycol at a mass ratio of 1:4.1 and add them to a flask, add 2.5 wt% of p - toluenesulfonic acid and 250 ppm of phenothiazine based on the total mass after mixing, react under reflux at 115 °C for 6.5 h, and purify to obtain substance A;

[0074] (2) Add substance A to deionized water and stir evenly. Then add a mercapto silane coupling agent with a mass ratio of 1:0.2 to substance A and an initiator accounting for 1.5 wt% of the total mass of substance A and the mercapto silane coupling agent. Stir at 50 °C for 2 h under ultraviolet light irradiation to obtain modified polyethylene glycol.

[0075] Example 4: Modify the diamond, roughen the surface and then coat it with silicon. The remaining processes are the same as those in Example 3:

[0076] (1) After rinsing 35.2 g of diamond powder with deionized water, immerse it in absolute ethanol and soak at 40 °C for 10 min. Take it out and add an etching powder with a mass ratio of 1:0.6 to the diamond powder (95 parts of nano-aluminum oxide, 2 parts of potassium chlorate, 2.5 parts of sodium perchlorate, 6 parts of nano-titanium powder, 12 parts of iron oxide powder). Transfer it to a homogenizer for homogenization treatment to obtain a mixture.

[0077] (2) Transfer the mixture to a muffle furnace, keep it at 475 °C for 5 min, then gradually heat it to 620 °C at a rate of 5 °C / min, keep it at this temperature for 10 min, cool it with the furnace, remove impurities, and rinse with deionized water to obtain pretreated diamond.

[0078] (3) Mix the pretreated diamond and nano-silicon powder evenly at a mass ratio of 1:0.8, conduct homogenization treatment, add it to a graphite mold pre-coated with a hexagonal boron nitride dispersion liquid, and perform spark plasma sintering at 2.5 Mpa and 1100 °C for 30 min to obtain modified diamond.

[0079] Comparative Example 1: Produced by the traditional hot casting process,

[0080] Load 35.2 g of diamond micropowder, 360.5 g of oxygen-free copper powder, 7.2 g of tin powder, and 16.3 g of silver powder into a ball milling and mixing tank and mix at a rotation speed of 120 rpm / min for 30 min; fill the mixed powder after mixing into a φ60.0 mm hot pressing and melting casting mold, and use a vacuum brazing furnace to heat it to 1100 °C at a heating rate of at least 10 °C / min. The vacuum degree of the furnace cavity is 1.5×10 -3 Pa. After cooling with the furnace and demolding, the size of the tool blank is measured as φ59.3 mm * 2.8 mm. Then, through post-treatment cutting and surface treatment with a 3000# diamond grinding disc, the sample size is processed to 58.29 mm (O.D) X 40.13 mm (I.D) with an average thickness of 0.183 mm to obtain a scribing soft knife.

[0081] Comparative Example 2: Based on Example 4, during the diamond modification process, only roughen the surface and do not coat it with silicon. The remaining processes are the same.

[0082] Preparation of Modified Diamond: (1) After rinsing 35.2 g of diamond powder with deionized water, immerse it in absolute ethanol and soak at 40 °C for 10 min. Take it out and add an etching powder with a mass ratio of 1:0.6 to the diamond powder (95 parts of nano-aluminum oxide, 2 parts of potassium chlorate, 2.5 parts of sodium perchlorate, 6 parts of nano-titanium powder, 12 parts of iron oxide powder), and transfer it to a homogenizer for homogenization treatment to obtain a mixture;

[0083] (2) Transfer the mixture to a muffle furnace, keep it at 475 °C for 5 min, then gradually heat it up to 620 °C at a rate of 5 °C / min, keep it at this temperature for 10 min, and cool it in the furnace. Remove impurities and rinse with deionized water to obtain modified diamond.

[0084] Comparative Example 3: Based on Example 4, no dispersant is added to the metal-diamond slurry, and the rest of the process is the same.

[0085] Performance Test: (1) Conduct a cutting performance test on Example 2 and Comparative Example 1: Use a precision dicing machine with a spindle speed of 25 Krpm and a feed speed of 1.5 mm / s to cut an aluminum nitride ceramic plate for testing. The test data is shown in Table 1; (2) Fix the cutting depth at 0.335 mm and the number of cutting paths at 35. Perform performance tests on other examples and comparative examples under the same conditions as in test experiment (1). The test data is shown in Table 2.

[0086] Table 1

[0087]

[0088] Table 2

[0089] Item Tool edge wear amount / μm Example 1 0.89 Example 2 0.84 Example 3 0.75 Example 4 0.67 Comparative Example 2 0.98 Comparative Example 3 0.80

[0090] Conclusion: (1) As can be seen from Table 1, the formula designed in the present invention and its unique preparation process can obtain a metal diamond scribing soft knife with excellent processing performance, which has stable performance, small machining chipping amount, the service life is increased by 1 / 3, and the production process is simple, the preparation cost is lower, and it can be produced batch by batch conveniently, solving the practical problems of difficult processing of brittle materials and high cost of preparation process equipment at present; (2) As can be seen from Table 2: In Example 3, the diamond surface was subjected to silicon plating treatment, the bonding property with the matrix copper was improved, the wear resistance was improved, and the wear amount of the tool edge was reduced; In Example 4, the diamond surface was roughened first and then silicon plated, the contact area was increased, the bonding degree was further enhanced, and the wear amount of the tool edge was further reduced; In Comparative Example 2, only the diamond was roughened and no silicon was plated. There were a large number of pits on the diamond surface after roughening. Without the wrapping of silicon, the diamond was prone to react with oxygen in the air, had a tendency to graphitize, the strength was reduced, and the wear amount of the tool edge increased significantly; In Comparative Example 3, the polyethylene glycol dispersant modified with siloxane was not added, and there was agglomeration of metal and diamond particles in the slurry, the strength decreased slightly, and the wear amount of the tool edge increased.

[0091] In summary, through the prior modification of diamond and the design of a unique preparation process, the present invention successfully provides a high-hardness diamond scribing soft knife with a relatively simple process, good wear resistance and cutting effect.

[0092] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent substitution on some of the technical features. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of a high-hardness diamond scribing soft knife, characterized in that: It includes the following steps: S1: Slurry preparation: Mix solid micro-powders and an organic carrier evenly and perform homogenization treatment to obtain a metal-diamond slurry; S2: Green body printing: Evenly coat the metal-diamond slurry on a wire mesh screen and then perform green body printing on a separator plate, followed by hot air drying to obtain a diamond scribing tool green body; S3: Diffusion sintering and forming: Place the diamond scribing tool green body into a vacuum sintering furnace, successively perform diffusion sintering and isostatic pressing treatment after cooling to obtain a rough diamond scribing tool; S4: Graphic processing: Perform film pasting, exposure, and etching treatment on the rough diamond scribing tool in sequence, and measure the dimensions after stripping processing to obtain a diamond scribing soft tool; Among them, the solid micro-powders include the following substances, by mass fraction: 10 - 20% diamond micro-powders, 80 - 85% oxygen-free copper powder, 1 - 3% tin powder, 3 - 5% silver powder; Among them, the diamond micro-powders are pre-modified, including the following steps: (1) After rinsing the diamond powder with deionized water, immerse it in absolute ethanol at 40 - 45 °C for 10 - 15 min, take it out and add etching powder with a mass ratio of 1:0.5 - 0.7 to the diamond powder, transfer it to a homogenizer for homogenization treatment to obtain a mixture; (2) Transfer the mixture to a muffle furnace, keep it at 450 - 500 °C for 5 - 10 min, then gradually heat it up to 600 - 650 °C at a rate of 5 - 10 °C / min, keep it at this temperature for 5 - 10 min, cool it with the furnace, remove impurities, and rinse it with deionized water to obtain pretreated diamond; (3) Mix the pretreated diamond and nano-silicon powder evenly at a mass ratio of 1:0.8 - 1, perform homogenization treatment, add it to a graphite mold pre-coated with a hexagonal boron nitride dispersion liquid, and perform spark plasma sintering at 2 - 3 Mpa and 1080 - 1120 °C for 30 - 45 min to obtain modified diamond.

2. The preparation method of a high-hardness diamond scribing soft knife according to claim 1, characterized in that: The metal-diamond slurry includes the following raw materials, by mass fraction: 75 - 85 parts of solid micro-powders, 15 - 25 parts of organic carrier.

3. The preparation method of a high-hardness diamond scribing soft knife according to claim 1, characterized in that: In step S3, the heating rate of the vacuum sintering furnace is 5 - 10 °C / min, and the sintering vacuum degree ≤ 0.01 Pa; during the diffusion sintering process: the diffusion sintering temperature is 650 - 900 °C, and the time is 30 - 120 min; during the isostatic pressing treatment process, the isostatic pressing treatment pressure is 10 - 50 Mpa, and the time is 10 - 60 min.

4. The preparation method of a high-hardness diamond scribing soft knife according to claim 1, characterized in that: In step S1: during the homogenization treatment process, the homogenization treatment rotation speed is 800 - 2000 r / min, and the time is 30 - 120 min; in step S2: during the green body printing process, the printing is automatic printing, and the printing speed is 5 - 10 mm / s; during the hot air drying process: the drying temperature is 50 - 80 °C, and the time is 5 - 15 min.

5. The preparation method of a high-hardness diamond scribing soft knife according to claim 1, characterized in that: The particle size of the diamond micro-powders is 10 - 20 μm, the particle size of the oxygen-free copper powder is 1 - 3 μm, the particle size of the tin powder is 1 - 5 μm, and the particle size of the silver powder is 1 - 3 μm; The organic carrier includes one or more of ethylene glycol, n-butanol, and terpineol.

6. The preparation method of a high-hardness diamond scribing soft knife according to claim 1, characterized in that: The mixture includes diamond powder and etching powder with a mass ratio of 1:0.5 - 0.7; the etching powder includes the following raw materials in parts by mass: 90 - 100 parts of nano-aluminum oxide, 2 - 3 parts of potassium chlorate, 2 - 3 parts of sodium perchlorate, 5 - 8 parts of nano-titanium powder, 10 - 15 parts of iron oxide powder; the modified diamond includes pretreated diamond and nano-silicon powder with a mass ratio of 1:0.8 - 1.

7. The preparation method of a high-hardness diamond scribing soft knife according to claim 2, characterized in that: The metal-diamond slurry further includes 2 - 5 parts of a dispersant, which is composed of the following raw materials in parts by mass: 20 - 25 parts of modified polyethylene glycol, 5 - 10 parts of polyvinyl alcohol, 2 - 3 parts of sodium dodecylbenzenesulfonate, 1 - 2 parts of polydimethylsiloxane, 60 - 70 parts of deionized water.

8. The preparation method of a high-hardness diamond scribing soft knife according to claim 7, characterized in that: The preparation method of the modified polyethylene glycol includes the following steps: (1) Mix acrylic acid and polyethylene glycol with a mass ratio of 1:4 - 4.2 and add them to a flask, add 2 - 3 wt% of p-toluenesulfonic acid and 240 - 260 ppm of phenothiazine based on the total mass after mixing, reflux and react at 110 - 120 °C for 6 - 7 h, and purify to obtain substance A; (2) Add substance A to deionized water and stir evenly, add a mercapto-silane coupling agent with a mass ratio of 1:0.2 - 0.25 to substance A and 1 - 3 wt% of an initiator based on the total mass of substance A and the mercapto-silane coupling agent, and stir at 45 - 55 °C for 2 - 3 h under ultraviolet light irradiation to obtain the modified polyethylene glycol.

9. A scribing soft knife prepared by the preparation method of a high-hardness diamond scribing soft knife according to any one of claims 1 - 8.

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