Preparation method of polycrystalline diamond grinding fluid for silicon carbide substrate DMP

Abstract

The invention provides a preparation method of a polycrystalline diamond grinding fluid for a silicon carbide substrate DMP. The polycrystalline diamond grinding fluid comprises the following components: pretreated polycrystalline diamond particles, an alcohol-based system, a polymeric dispersant, a stabilizer, a lubricant, a pH regulator, an antibacterial agent, a microemulsion forming agent and deionized water. The development of the grinding fluid is different from the traditional grinding of a copper disc matched with a polycrystalline grinding material, the polycrystalline matched with a polyurethane grinding pad has better surface effect and grinding rate, the surface roughness Ra can reach 1-2nm, the submerging rate can reach 0.15-0.25 mu m / min, and a surface damage layer is relatively small; an alcohol-based system is adopted in the system and comprises but is not limited to one or a mixed solution of more of ethylene glycol, glycerol, ethanol and triethylene glycol; and the polymeric dispersant suitable for an alcohol system is added, so that the dispersity of the particles is ensured while the speed is ensured, and scratches caused by soft agglomeration among the particles are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of polishing liquid, and more specifically to a method for preparing polycrystalline diamond polishing liquid for DMP of silicon carbide substrate. Background Art

[0002] Silicon carbide substrate is a basic material used to manufacture semiconductor devices. It is mainly composed of silicon carbide single crystals and has many excellent physical properties, which makes it widely used in the manufacture of high-power, high-frequency electronic devices and optoelectronic devices. Silicon carbide substrates are widely used in semiconductor manufacturing, and their surface grinding is one of the important steps to ensure the quality of semiconductor device preparation.

[0003] Polycrystalline diamond slurry is a liquid abrasive used for precision grinding. Its main components are polycrystalline diamond particles and alcohol-based systems. It is widely used in various manufacturing and processing industries, especially in applications that require high-precision and high-hardness materials, such as semiconductor, optics and ceramic processing. The semiconductor industry is mainly used to process silicon carbide substrates, gallium nitride substrates and other semiconductor materials, and can ensure efficient grinding rates and high-precision surface quality; the optical industry is mainly used to grind watch mirrors, mobile phone camera lenses and other optical components; the ceramic industry is mainly used to grind structural ceramics, electronic ceramics and other materials.

[0004] Existing polycrystalline diamond particles aggregate into larger agglomerates during the grinding process. This phenomenon leads to uneven distribution of particles in the grinding fluid, which in turn generates localized high pressure on the silicon carbide substrate, which may cause scratches. In addition, the polycrystalline diamond slurry used in the existing DMP process of silicon carbide substrates is usually not environmentally friendly, mainly due to the following factors: Chemical composition: The grinding fluid may contain harmful chemicals, such as certain dispersants and stabilizers, which are potentially harmful to the environment and human body; Waste liquid treatment: The waste liquid generated during the grinding process needs to be properly treated. Improper treatment may cause environmental pollution; Resource consumption: The production and use of polycrystalline diamond slurry involves a lot of energy and resources, increasing the environmental burden.

[0005] The present invention adopts an alcohol-based system, including but not limited to ethylene glycol, propylene glycol, ethanol, triethylene glycol, etc.; and adds but not limited to a polymer dispersant suitable for the alcohol system, such as caprolactam polyol-polyethyleneimine block copolymer type dispersant, acrylate polymer type dispersant, polyurethane or polyester polymer dispersant, etc., to ensure the rate while also ensuring the dispersion of the particles, avoiding scratches caused by soft agglomeration between particles. Summary of the invention

[0006] The present invention aims to solve the technical problems raised by the above background technology. The present invention provides the following technical solutions: a polycrystalline diamond polishing liquid for DMP of silicon carbide substrate, comprising the following components: pretreated polycrystalline diamond particles, alcohol-based system, polymer dispersant, stabilizer, lubricant, pH adjuster, antimicrobial agent, microemulsion former and deionized water; Relative to 100 parts by weight of the pretreated polycrystalline diamond particles, the content of the alcohol-based system is 10 to 30 parts by weight; the content of the polymer dispersant is 0.5 to 5 parts by weight; the content of the lubricant is 2 to 10 parts by weight; the content of the pH regulator is 0.1 to 2 parts; the content of the stabilizer is 0.5 to 3 parts by weight; the content of the antibacterial agent is 0.1 to 1 part by weight; the content of the microemulsion forming agent is 1 to 5 parts by weight; the content of the deionized water is 45 to 85 parts by weight; The pretreatment steps of the pretreated polycrystalline diamond particles are as follows: the polycrystalline diamond particles are cleaned, dried, surface modified, graded and screened, and heat treated.

[0007] In a specific embodiment, the alcohol-based system includes at least one of ethylene glycol, glycerol, ethanol, and triethylene glycol.

[0008] In a specific embodiment, the polymer dispersant includes at least one of a caprolactam polyol-polyethyleneimine block copolymer type dispersant, an acrylate polymer dispersant, a polyurethane or polyester polymer dispersant.

[0009] In a specific embodiment, the stabilizer includes at least one of bio-based polyvinyl alcohol or polylactic acid.

[0010] In a specific embodiment, the lubricant includes at least one of vegetable oil, vegetable fatty acid and plant extract.

[0011] In a specific embodiment, the pH regulator includes at least one of citric acid, acetic acid, and lactic acid; the antibacterial agent includes at least one of tea tree oil, rosemary extract, and lemon extract; the microemulsion forming agent includes at least one of polysorbate and a plant-based surfactant. A method for preparing a polycrystalline diamond grinding liquid for DMP of a silicon carbide substrate comprises the following steps: S1. Add deionized water into a stirring container; S2, adding a polymer dispersant to deionized water; S3, slowly adding the pre-treated polycrystalline diamond particles into the stirring container; S4, adding a microemulsion forming agent; S5, adding stabilizer; S6, adding lubricant; S7, adjusting the pH value of the liquid using a pH adjuster; S8, adding antimicrobial agent; S9, performing final stirring on the entire mixed liquid; S10. Check the performance and stability of the liquid and make adjustments if necessary.

[0012] In a specific embodiment, in steps S1-S9, the stirring temperature is 20-25°C.

[0013] In a specific embodiment, in steps S1-S9, the stirring rate of the stirring is 200-300 rpm.

[0014] In a specific embodiment, in steps S1-S9, the stirring time is 15-30 minutes. Beneficial Effects

[0015] 1. The development of the polishing liquid of the present invention is different from the traditional polishing on a copper plate. It can be matched with a polyurethane polishing pad to achieve a better surface effect. Ra can reach within 2nm, the speed can reach more than 0.2um / min, and the surface shape is good; 2. The system of the present invention adopts an alcohol-based system, including but not limited to ethylene glycol, propylene glycol, ethanol, triethylene glycol, etc.; and adds but not limited to a polymer dispersant suitable for the alcohol system, caprolactam polyol-polyethyleneimine block copolymer type dispersant, acrylate polymer dispersant, polyurethane or polyester polymer dispersant, etc., to ensure the rate while also ensuring the dispersion of the particles, avoiding scratches caused by soft agglomeration; 3. The present invention adopts a stabilizer including at least one of bio-based polyvinyl alcohol or polylactic acid, a lubricant including at least one of vegetable oil, vegetable fatty acid and plant extract, a pH adjuster including at least one of citric acid, acetic acid and lactic acid, an antibacterial agent including at least one of tea tree oil, rosemary extract and lemon extract, and a microemulsion former including at least one of polysorbate and a plant-based surfactant. The above ingredients are all non-toxic and natural ingredients, making the grinding fluid more environmentally friendly; 4. In summary, the use of non-toxic, natural stabilizers, lubricants, pH regulators, antibacterial agents and microemulsion formers to prepare grinding fluids not only makes them more environmentally friendly, but also has the following benefits: Reduce harm to the human body: Natural ingredients usually have less irritation to the skin and respiratory tract, reducing the health risks of operators during use; Reduce environmental pollution: Natural and bio-based ingredients have less impact on the environment during degradation, reducing pollution to water and soil; Improved wastewater treatment: Environmentally friendly ingredients are generally easier to handle and degrade, making the wastewater treatment process simpler and more economical, helping to reduce the burden on treatment facilities; Improve grinding efficiency: Natural lubricants such as vegetable oils and vegetable fatty acids may provide better lubrication properties, reduce frictional heat, improve grinding efficiency and workpiece surface finish; Improved safety: Natural antimicrobial agents such as tea tree oil and rosemary extract have natural antimicrobial properties, which can reduce the growth of microorganisms in the grinding fluid and improve the sanitation of the operating environment; Reduce wear on materials: The use of non-toxic, natural grinding fluid has less erosion on hard materials such as silicon carbide, reducing damage to materials during the grinding process; Supporting Sustainability: The use of bio-based and plant-based ingredients is in line with the principles of green chemistry and sustainable development, helping to drive the industry towards a more environmentally friendly direction. DETAILED DESCRIPTION

[0016] The present invention provides a method for preparing a polycrystalline diamond polishing liquid for DMP of a silicon carbide substrate. The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0017] The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0018] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art. Example

[0019] This example provides a grinding liquid, the components and contents of which are shown in Table 1, and the preparation method thereof is as follows: The pretreatment steps of the polycrystalline diamond particles are as follows: washing, drying, surface modification, grading and screening, and heat treatment of the polycrystalline diamond particles; The specific method is as follows: Cleaning: Purpose: To remove impurities and contaminants from the particle surface; Method: Clean the particles using an ultrasonic cleaner and deionized water. A thorough rinse with an organic solvent such as ethanol or acetone may also be required.

[0020] dry: Purpose: To remove residual water or solvent from the cleaning process.

[0021] Method: The cleaned granules are placed in an oven and dried at a controlled temperature, usually between 60-120°C.

[0022] Surface modification: Purpose: To improve the surface properties of particles and increase their compatibility with other components.

[0023] Methods: The surface properties of particles can be modified by chemical treatment (such as acid treatment or base treatment) or physical treatment (such as plasma treatment).

[0024] Grading and screening: Purpose: To ensure that the particles are of uniform size to meet application requirements.

[0025] Method: Use a vibrating screen or air classifier to classify the particles by size and remove particles that do not meet the specifications.

[0026] Heat Treatment: Purpose: To further enhance the performance of particles and improve their structural stability.

[0027] Method: Heat treating particles at high temperatures to enhance their hardness or other properties.

[0028] Finally, the pre-treated polycrystalline diamond particles can be characterized and analyzed: Purpose: To confirm the effect of pretreatment and ensure the quality of particles.

[0029] Methods: Microscopes, particle size analyzers, X-ray diffractometers and other tools are used to analyze the morphology, size and crystal structure of the particles.

[0030] A method for preparing a polycrystalline diamond grinding liquid for DMP of a silicon carbide substrate comprises the following steps: S1. Add deionized water into a stirring container; S2, adding a polymer dispersant to deionized water; S3, slowly adding the pre-treated polycrystalline diamond particles into the stirring container; S4, adding a microemulsion forming agent; S5, adding stabilizer; S6, adding lubricant; S7, adjusting the pH value of the liquid using a pH adjuster; S8, adding antimicrobial agent; S9, performing final stirring on the entire mixed liquid; S10. Check the performance and stability of the liquid and make adjustments if necessary.

[0031] In the above steps S1-S9, the stirring temperature is 20-25° C., the stirring speed is 200-300 rpm, and the stirring time is 15-30 minutes.

[0032] In step S10, the detection items include: particle size distribution, pH value, stability, etc.

[0033] Embodiments 2 to 5 Examples 2 to 5 provide a series of grinding liquids, and the preparation method thereof is the same as that of Example 1, except that the amounts of the components are different. The amounts of the components are shown in Table 1.

[0034] Table 1 Examples 1 to 5 (parts by weight) Example

[0035] Comparative Examples 1-5 provide a method for preparing a polycrystalline diamond polishing liquid for DMP of a silicon carbide substrate. The component content and preparation method thereof are basically the same as those in Example 1, as shown in Table 2. The difference is that: The alcohol-based system includes at least one of ethylene glycol, propylene glycol, ethanol, and triethylene glycol; The polymer dispersant includes at least one of a caprolactam polyol-polyethyleneimine block copolymer type dispersant, an acrylate polymer dispersant, a polyurethane or polyester polymer dispersant; The stabilizer includes at least one of bio-based polyvinyl alcohol or polylactic acid; The lubricant includes at least one of a vegetable oil, a vegetable fatty acid, and a vegetable extract; The pH adjuster includes at least one of citric acid, acetic acid, and lactic acid; The antimicrobial agent includes at least one of tea tree oil, rosemary extract, and lemon extract; The microemulsion former includes at least one of a polysorbate and a plant-based surfactant.

[0036] Table 2 Examples 1 to 5 (Details of ingredients used)

[0037] These ingredients have the following effects in polycrystalline diamond slurry for DMP of silicon carbide substrates: Alcohol-based systems: Ethylene glycol, propylene glycol, etc. are usually biodegradable, reducing environmental burden; Polymer dispersants: Using bio-based or degradable polymer materials, such as polyurethane, can help reduce plastic pollution; Stabilizer: Bio-based polyvinyl alcohol or polylactic acid is a renewable resource, reducing the use of petroleum-based chemicals; Lubricants: Plant oils and extracts are renewable in origin, reducing reliance on petrochemicals; pH adjusters: citric acid, acetic acid, etc. are usually more environmentally friendly and easy to decompose; Antimicrobial agents: Natural extracts such as tea tree oil and rosemary extract are more environmentally friendly than synthetic antimicrobials; Microemulsion formers: Plant-based surfactants and polysorbates have a lower environmental impact.

[0038] In summary: The development of the polishing liquid of the present invention is different from the traditional polishing on a copper disk, and can be matched with a polyurethane polishing pad to achieve a better surface effect, wherein the roughness Ra can reach 1-2nm, the speed can reach 0.15-0.25um / min, and the surface damage layer is low; The system of the present invention adopts an alcohol-based system, including but not limited to ethylene glycol, propylene glycol, ethanol, triethylene glycol, etc.; and is added with but not limited to a polymer dispersant suitable for the alcohol system, such as a caprolactam polyol-polyethyleneimine block copolymer dispersant, an acrylate polymer dispersant, a polyurethane or polyester polymer dispersant, etc., to ensure the rate while also ensuring the dispersion of the particles, and avoiding scratches caused by soft agglomeration; The present invention uses non-toxic, natural stabilizers, lubricants, pH regulators, antibacterial agents and microemulsion forming agents to prepare the grinding liquid, which not only makes it more environmentally friendly, but also has the following advantages: Reduce harm to the human body: Natural ingredients usually have less irritation to the skin and respiratory tract, reducing the health risks of operators during use; Reduce environmental pollution: Natural and bio-based ingredients have less impact on the environment during degradation, reducing pollution to water and soil; Improved wastewater treatment: Environmentally friendly ingredients are generally easier to handle and degrade, making the wastewater treatment process simpler and more economical, helping to reduce the burden on treatment facilities; Improve grinding efficiency: Natural lubricants such as vegetable oils and vegetable fatty acids may provide better lubrication properties, reduce frictional heat, improve grinding efficiency and workpiece surface finish; Improved safety: Natural antimicrobial agents such as tea tree oil and rosemary extract have natural antimicrobial properties, which can reduce the growth of microorganisms in the grinding fluid and improve the sanitation of the operating environment; Reduce wear on materials: The use of non-toxic, natural grinding fluid has less erosion on hard materials such as silicon carbide, reducing damage to materials during the grinding process; Supporting Sustainability: The use of bio-based and plant-based ingredients is in line with the principles of green chemistry and sustainable development, helping to drive the industry towards a more environmentally friendly direction.

Claims

1. A polycrystalline diamond polishing liquid for DMP of silicon carbide substrate, characterized in that: The components include: pretreated polycrystalline diamond particles, alcohol-based system, polymer dispersant, stabilizer, lubricant, pH adjuster, antimicrobial agent, microemulsion former and deionized water; Relative to 100 parts by weight of the pretreated polycrystalline diamond particles, the content of the alcohol-based system is 10 to 30 parts by weight; the content of the polymer dispersant is 0.5 to 5 parts by weight; the content of the lubricant is 2 to 10 parts by weight; the content of the pH regulator is 0.1 to 2 parts; the content of the stabilizer is 0.5 to 3 parts by weight; the content of the antibacterial agent is 0.1 to 1 part by weight; the content of the microemulsion forming agent is 1 to 5 parts by weight; the content of the deionized water is 45 to 85 parts by weight; The pretreatment steps of the pretreated polycrystalline diamond particles are as follows: the polycrystalline diamond particles are cleaned, dried, surface modified, graded and screened, and heat treated.

2. The polycrystalline diamond polishing liquid for DMP of silicon carbide substrate according to claim 1, characterized in that: The alcohol-based system includes at least one of ethylene glycol, propylene glycol, ethanol and triethylene glycol.

3. The polycrystalline diamond polishing liquid for DMP of silicon carbide substrate according to claim 1, characterized in that: The polymer dispersant includes at least one of a caprolactam polyol-polyethyleneimine block copolymer type dispersant, an acrylate polymer dispersant, a polyurethane or polyester polymer dispersant.

4. The polycrystalline diamond polishing liquid for DMP of silicon carbide substrate according to claim 1, characterized in that: The stabilizer includes at least one of bio-based polyvinyl alcohol or polylactic acid.

5. The polycrystalline diamond polishing liquid for DMP of silicon carbide substrate according to claim 1, characterized in that: The lubricant includes at least one of vegetable oil, vegetable fatty acid and plant extract.

6. The polycrystalline diamond polishing liquid for DMP of silicon carbide substrate according to claim 1, characterized in that: The pH regulator includes at least one of citric acid, acetic acid, and lactic acid; the antibacterial agent includes at least one of tea tree oil, rosemary extract, and lemon extract; and the microemulsion former includes at least one of polysorbate and a plant-based surfactant.

7. A method for preparing a polycrystalline diamond polishing liquid for DMP of a silicon carbide substrate according to any one of claims 1 to 6, characterized in that: The steps include: S1. Add deionized water into a stirring container; S2, adding a polymer dispersant to deionized water; S3, slowly adding the pre-treated polycrystalline diamond particles into the stirring container; S4, adding a microemulsion forming agent; S5, adding stabilizer; S6, adding lubricant; S7, adjusting the pH value of the liquid using a pH adjuster; S8, adding antimicrobial agent; S9, performing final stirring on the entire mixed liquid; S10. Check the performance and stability of the liquid and make adjustments if necessary.

8. The method for preparing a polycrystalline diamond polishing liquid for DMP of a silicon carbide substrate according to claim 7, characterized in that: In steps S1-S9, the stirring temperature is 20-25°C.

9. The method for preparing a polycrystalline diamond polishing liquid for DMP of a silicon carbide substrate according to claim 7, characterized in that: In steps S1-S9, the stirring rate of the stirring is 200-300 rpm.

10. The method for preparing a polycrystalline diamond polishing liquid for DMP of a silicon carbide substrate according to claim 7, characterized in that: In steps S1-S9, the stirring time is 15-30 minutes.

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