Preparation method of high-purity spherical silica sol for electronic polishing

Abstract

The present invention provides a method for preparing high-purity spherical silica sol for electronic polishing, which relates to the field of inorganic compound materials and includes: simultaneously injecting tetramethoxysiloxane and a dispersion liquid from two feeding ports of a first-stage silicon carbide microchannel reactor to carry out a hydrolysis polymerization reaction to obtain solution A; simultaneously injecting solution A and an acidic hydrolysis solution from two feeding ports of a second-stage silicon carbide microchannel reactor to carry out a particle homogenization reaction to obtain solution B; simultaneously injecting solution B and a stabilizer from two feeding ports of a third-stage silicon carbide microchannel reactor to carry out a particle stability reaction to obtain high-purity spherical silica sol; performing solvent replacement on the high-purity spherical silica sol, and after the solvent replacement, concentrating it through a membrane filter until the silica content is greater than 20% to obtain ultra-high-purity spherical silica sol with a total metal ion content of less than 1 ppm. The high-purity spherical silica sol prepared by the present invention has uniform particle size, which helps to improve the polishing effect.

Description

Technical Field

[0001] The present invention relates to the field of electronic-grade high-purity inorganic silicon compound materials, and more particularly, to a method for preparing high-purity spherical silica sol for electronic polishing. Background Art

[0002] Silica sol is a dispersion of nano-scale silicon dioxide particles in water or a solvent. Since the SiO in silica sol 2 contains a large amount of water and hydroxyl groups, it belongs to a colloidal solution and has properties such as odorlessness, non-toxicity, high dispersibility, and high temperature resistance. It is widely used in fields such as papermaking, casting, coatings, and chemical mechanical polishing. In recent years, silica sol for electronic polishing has been widely used in the chemical mechanical polishing of semiconductor devices and semiconductor materials such as silicon, germanium, and indium phosphide. With the development of semiconductor devices, the requirements for the surface quality and precision of devices are getting higher and higher. The metal ions contained in silica sol, as well as the morphology and particle size of silica sol, have a serious impact on its application. The existing methods for preparing silica sol have the following defects: the hydrolysis polymerization reaction rate is difficult to control, the metal ion content is relatively high, the particle size of the prepared silica sol is uneven, and the particle size and particle shape are difficult to control.

[0003] Therefore, how to prepare spherical silica sol with uniform particle size and capable of improving the electronic polishing effect has become a technical problem to be solved. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the above-mentioned prior art or related technologies, and provides a method for preparing high-purity spherical silica sol for electronic polishing. The prepared high-purity spherical silica sol has uniform particle size and can improve the electronic polishing effect.

[0005] The first aspect of the present invention discloses a preparation method of high-purity spherical silica sol for electronic polishing, comprising: simultaneously injecting tetramethoxysilane and a dispersion liquid into two feed ports of a first-stage silicon carbide microchannel reactor, wherein the injection rate of tetramethoxysilane is 1.5 - 2.1 ml / min, and the injection rate of the dispersion liquid is 3.0 - 16.8 ml / min. The dispersion liquid comprises a composite alcohol, ultrapure water, and a weak base; performing a hydrolysis polymerization reaction at a temperature of 5 - 15°C, controlling the temperature fluctuation during the reaction within 1.2°C, and obtaining solution A from the outlet of the first-stage silicon carbide microchannel reactor; connecting the outlet of the first-stage silicon carbide microchannel reactor to a second-stage silicon carbide microchannel reactor, and simultaneously injecting solution A and an acidic hydrolysis solution into two feed ports of the second-stage silicon carbide microchannel reactor, wherein the injection rate of the acidic hydrolysis solution is 9.0 - 95.0 ml / min; the acidic hydrolysis solution comprises tetramethoxysilane, ultrapure water, and an acid, and the pH value is 2 - 4; performing a particle homogenization reaction at a temperature of 50 - 85°C, and obtaining solution B from the outlet of the second-stage silicon carbide microchannel reactor; connecting the outlet of the second-stage silicon carbide microchannel reactor to a third-stage silicon carbide microchannel reactor, and simultaneously injecting solution B and a stabilizer into two feed ports of the third-stage silicon carbide microchannel reactor, wherein the injection rate of the stabilizer is 0.01 - 9.1 ml / min; the stabilizer comprises ultrapure water, an organic base, and a viscosity reducer; performing a particle stability reaction at a temperature of 20 - 30°C, and obtaining high-purity spherical silica sol from the outlet of the third-stage silicon carbide microchannel reactor.

[0006] According to the preparation method of high-purity spherical silica sol for electronic polishing provided by the present invention, preferably, it further comprises: collecting the high-purity spherical silica sol prepared by the third-stage silicon carbide microchannel reactor into a reaction kettle, heating to 100°C and simultaneously adding ultrapure water to maintain a constant liquid level for solvent replacement; concentrating the high-purity spherical silica sol after solvent replacement through a membrane filter to a silica content greater than 20% to obtain an ultra-high-purity spherical silica sol with a total metal ion content less than 1 ppm.

[0007] According to the preparation method of high-purity spherical silica sol for electronic polishing provided by the present invention, preferably, the mass ratio of tetramethoxysilane to the dispersion liquid is 1:2 - 8; the mass ratio of the composite alcohol, ultrapure water, and weak base in the dispersion liquid is 10:1.3 - 1.8:0.1 - 0.5.

[0008] According to the preparation method of high-purity spherical silica sol for electronic polishing provided by the present invention, preferably, the composite alcohol is a mixture of two or more of isopropyl alcohol, methanol, methyl ether, ethanol, and acetone; the weak base is a mixture of two or more of ammonia water, monoethanolamine, diethanolamine, triethanolamine, and ethylenediamine.

[0009] According to the preparation method of high-purity spherical silica sol for electronic polishing provided by the present invention, preferably, the mass ratio of solution A to the acidic hydrolysis solution is 1:3 to 5; the mass ratio of tetramethoxysiloxane, ultrapure water and acid in the acidic hydrolysis solution is 1:2 to 5:0.01 to 0.001.

[0010] According to the preparation method of high-purity spherical silica sol for electronic polishing provided by the present invention, preferably, the mass ratio of solution B to the stabilizer is 100:1 to 8; the mass ratio of ultrapure water, organic base and viscosity reducer in the stabilizer is 100:2 to 6:0.05 to 0.1.

[0011] According to the preparation method of high-purity spherical silica sol for electronic polishing provided by the present invention, preferably, the acid includes one or more of sulfuric acid, hydrochloric acid, nitric acid, oxalic acid, citric acid and acetic acid; the organic base includes ethylenediamine and / or tetramethylammonium hydroxide; the viscosity reducer includes polyethylene glycol and / or nonylphenol.

[0012] According to the preparation method of high-purity spherical silica sol for electronic polishing provided by the present invention, preferably, the total ion content of sodium ions, aluminum ions, copper ions, iron ions, calcium ions, magnesium ions and potassium ions in tetramethoxysiloxane, composite alcohol, weak base, acid, organic base and viscosity reducer used in the reaction process is less than 1 ppb.

[0013] According to the preparation method of high-purity spherical silica sol for electronic polishing provided by the present invention, preferably, the pumps, pipelines, valves and storage tanks in contact with the materials during the reaction process are all made of non-metallic materials, and the first-stage silicon carbide microchannel reactor, the second-stage silicon carbide microchannel reactor and the third-stage silicon carbide microchannel reactor are hermetically connected to form a closed reaction environment.

[0014] The second aspect of the present invention also discloses a high-purity spherical silica sol for electronic polishing, which is prepared according to the preparation method of the high-purity spherical silica sol for electronic polishing disclosed in any of the above technical solutions.

[0015] The beneficial effects achieved by the present invention at least include: Utilizing the advantages of the microchannel reactor and special reaction conditions, the rate of the hydrolysis polymerization reaction can be effectively controlled, solving the problem that the rate of the hydrolysis polymerization reaction of tetramethoxysiloxane is difficult to control, and successfully preparing an ultra-high-purity spherical silica sol with high stability and good uniformity. This method has the advantages of simple operation and a closed reaction process, can avoid air pollution and does not volatilize harmful substances, and can be continuously produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Shows a schematic flow chart of the preparation method of high-purity spherical silica sol for electronic polishing according to an embodiment of the present invention.

[0017] Figure 2 Shows a schematic micrograph of high-purity spherical silica sol for electronic polishing according to an embodiment of the present invention.

[0018] Figure 3 Shows a schematic micrograph of high-purity spherical silica sol for electronic polishing according to another embodiment of the present invention.

[0019] Figure 4 Shows a schematic micrograph of high-purity spherical silica sol for electronic polishing according to another embodiment of the present invention. Detailed implementation manners

[0020] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0021] As Figure 1 shown, according to an embodiment of the present invention, a preparation method of high-purity spherical silica sol for electronic polishing is disclosed, including:

[0022] Step S1, hydrolysis polymerization reaction: Tetramethoxysilane and the dispersion liquid are simultaneously injected from two feed ports of the first-stage silicon carbide microchannel reactor, and the hydrolysis polymerization reaction is carried out at a temperature of 5-15 °C. During the reaction process, the temperature fluctuation is less than 1.2 °C, and solution A is obtained from the outlet of the silicon carbide microchannel reactor.

[0023] In this step, tetramethoxysilane is easily dispersed in the composite alcohol, which is beneficial to the hydrolysis polymerization reaction, avoiding the problem of uneven local reaction caused by uneven dispersion and forming particles with uneven sizes. Heat is released during the reaction process of tetramethoxysilane. The higher the temperature, the faster the hydrolysis polymerization reaction, which affects the formation of silica sol. The weak base is composed of two or more of ammonia water, monoethanolamine, diethanolamine, triethanolamine and ethylenediamine. The weak base has strong pH value stability, and the pH value fluctuation during the reaction process is small, which is beneficial to stabilizing the hydrolysis polymerization reaction rate. The mass ratio of tetramethoxysilane to the dispersion liquid is 1:2-8. The injection rate of tetramethoxysilane is 1.5-2.1 ml / min, and the injection rate of the dispersion liquid is 3.0-16.8 ml / min. The dispersion liquid is a composite alcohol, ultrapure water and a weak base, and the ratio is 10:1.3-1.8:0.1-0.5; the composite alcohol is a mixture of isopropanol and two or more of methanol, methyl ether, ethanol and acetone. Take two or more of methanol, methyl ether, ethanol and acetone to form a mixture, and mix 1-3 parts by mass of this mixture with 10 parts by mass of isopropanol to obtain the composite alcohol. The temperature of the silicon carbide microchannel reactor is controlled at 5-15 °C, the optimal choice is 8-13 °C, the reaction temperature fluctuation is less than 1.2 °C, and the optimal reaction temperature fluctuation is less than 0.8 °C.

[0024] Step S2, Particle homogenization reaction: Solution A and the acidic hydrolysis solution are simultaneously fed into the second-stage silicon carbide microchannel reactor through two feed ports, and the particle homogenization reaction is carried out at a temperature of 50 - 85°C to obtain Solution B from the outlet of the second-stage silicon carbide microchannel reactor.

[0025] In this step, the acidic hydrolysis solution is a mixture of tetramethoxysiloxane, ultrapure water, and acid with a mass ratio of 1:2 - 5:0.01 - 0.001, a pH value between 2 - 4, and the optimal pH value is 2 - 3. The mass ratio of Solution A to the acidic hydrolysis solution is 1:2 - 5, and the feeding rate of the acidic hydrolysis solution is 9.0 - 95.0 ml / min. The optimal temperature is selected to be 70 - 80°C.

[0026] Step S3, Particle stabilization reaction: Solution B and the stabilizer are simultaneously fed into the third-stage silicon carbide microchannel reactor through two feed ports, and the particle stability reaction is carried out at a temperature of 20 - 30°C to obtain high-purity spherical silica sol with high particle uniformity and good stability from the outlet of the third-stage silicon carbide microchannel reactor.

[0027] In this step, the mass ratio of Solution B to the stabilizer is 100:1 - 8, and the feeding rate of the stabilizer is 0.01 - 9.1 ml / min. The stabilizer is a mixture of ultrapure water, organic strong base, and viscosity reducer with a mass ratio of 100:2 - 6:0.05 - 0.1. The organic strong base includes ethylenediamine and tetramethylammonium hydroxide. The viscosity reducer includes polyethylene glycol and nonylphenol.

[0028] Step S4, Solvent replacement: The high-purity spherical silica sol produced by the third-stage silicon carbide microchannel reactor is collected in a reaction kettle, heated to 100°C, and ultrapure water is added simultaneously to maintain a constant liquid level. When the alcohol content is detected to be less than 0.1 g / L, the solvent replacement is completed.

[0029] Step S5, Concentration: The high-purity spherical silica sol after solvent replacement is concentrated through a membrane filter to a silica content > 20% to obtain ultra-high-purity spherical silica sol with a total metal ion content of less than 1 ppm.

[0030] According to the above embodiments, the present invention controls the purity of silica sol by the following methods: (1) The total ion content of sodium ions, aluminum ions, copper ions, iron ions, calcium ions, magnesium ions and potassium ions in tetramethoxysiloxane, composite alcohol, weak base, acid, organic base and viscosity reducer used in the reaction process is less than 1 ppb; (2) The reactor used is made of non-metallic material, and satisfies the simultaneous feeding of two or more materials, and the feeding flow rate range satisfies 0-200 ml / min, and can be accurately controlled within the temperature range of 0-150 °C, and the temperature difference is less than 0.5 °C, supporting continuous production; (3) Pumps, pipelines, valves and storage tanks in contact with materials during the reaction process are all made of non-metallic materials. The first-stage silicon carbide microchannel reactor, the second-stage silicon carbide microchannel reactor and the third-stage silicon carbide microchannel reactor are hermetically connected to form a closed reaction environment.

[0031] As Figure 2 , Figure 3 and Figure 4 shown, according to another embodiment of the present invention, the specific implementation of the preparation method of high-purity spherical silica sol for electronic polishing provided in the above embodiment is also disclosed:

[0032] Example 1:

[0033] Isopropanol, ethanol, ultrapure water and ammonia water are proportioned according to the mass ratio of 4:6:1.5:0.3 to obtain a dispersion liquid. Tetramethoxysiloxane, ultrapure water and hydrochloric acid are proportioned according to the mass ratio of 1:3:0.004 to obtain an acidic hydrolysis solution with a pH of 2.3. Ultrapure water, ethylenediamine and polyethylene glycol are proportioned according to the mass ratio of 100:3:0.06 to obtain a stabilizer. The temperature of the first-stage silicon carbide microchannel reactor is set to 12.0 °C, the injection speed of tetramethoxysiloxane is set to 1.7 ml / min, the injection speed of the dispersion liquid is set to 11.9 ml / min, the temperature of the second-stage silicon carbide microchannel reactor is set to 76 °C, and the injection speed of the acidic hydrolysis solution is set to 9.5 ml / min. The temperature of the third-stage silicon carbide microchannel reactor is set to 22 °C, and the injection speed of the stabilizer is set to 0.4 ml / min. When the temperature reaches, turn on the pumps of the first stage, the second stage and the third stage in sequence to start the reaction. When the reaction temperature fluctuation of the first-stage, second-stage and third-stage silicon carbide microchannel reactors is less than 0.8 °C, high-purity spherical silica sol with a particle size of 16 nm is obtained from the outlet of the third-stage silicon carbide microchannel reactor. The high-purity spherical silica sol produced by the third-stage silicon carbide microchannel reactor is collected in a reaction kettle, heated to 100 °C, and ultrapure water is added at the same time to maintain the liquid level constant. When the alcohol content is detected to be less than 0.1 g / L, the solvent replacement is completed. The high-purity spherical silica sol after solvent replacement is concentrated to 25% of silicon dioxide content through a membrane filter to obtain an ultra-high-purity silica sol with a total metal ion content of 0.3 ppm, and its particle morphology is spherical, as Figure 2 shown.

[0034] Example 2: Preparation of 78 nm spherical silica sol;

[0035] Isopropanol, ethanol, ultrapure water and triethanolamine were proportioned according to the mass ratio of 2:8:1.5:0.2 to obtain a dispersion. Tetramethoxysilane, ultrapure water and sulfuric acid were proportioned according to the mass ratio of 1:3:0.006 to obtain an acidic hydrolysis solution with a pH of 2.1. Ultrapure water, tetramethylammonium hydroxide and polyethylene glycol were proportioned according to the mass ratio of 100:2:0.06 to obtain a stabilizer. The temperature of the first-stage silicon carbide microchannel reactor was set at 13.0 °C, the injection rate of tetramethoxysilane was set at 1.8 ml / min, and the injection rate of the dispersion was set at 11.6 ml / min. The temperature of the second-stage silicon carbide microchannel reactor was set at 77 °C, and the injection rate of the acidic hydrolysis solution was set at 10.5 ml / min. The temperature of the third-stage silicon carbide microchannel reactor was set at 22 °C, and the injection rate of the stabilizer was set at 0.3 ml / min. When the temperature reached, the pumps of the first, second and third stages were turned on in sequence to start the reaction. When the reaction temperature fluctuations of the first, second and third-stage silicon carbide microchannel reactors were less than 0.8 °C, high-purity spherical silica sol with a particle size of 78 nm was obtained from the outlet of the third-stage silicon carbide microchannel reactor. The high-purity spherical silica sol produced by the third-stage silicon carbide microchannel reactor was collected in a reaction kettle and heated to 100 °C. At the same time, ultrapure water was added to maintain a constant liquid level. When the alcohol content was detected to be less than 0.1 g / L, the solvent replacement was completed. The high-purity spherical silica sol after solvent replacement was concentrated through a membrane filter to a silica content of 26% to obtain an ultrapure silica sol with a total metal ion content of 0.2 ppm, and its particle morphology was spherical, as Figure 3 shown.

[0036] Example 3: Preparation of 118 nm spherical silica sol;

[0037] Methanol, ethanol, ultrapure water and triethanolamine are proportioned by mass ratio of 1:9:1.5:0.2 to obtain a dispersion liquid. Tetramethoxysiloxane, ultrapure water and citric acid are proportioned by mass ratio of 1:3:0.009 to obtain an acidic hydrolysis solution with a pH of 2.8. Ultrapure water, tetramethylammonium hydroxide and nonylphenol are proportioned by mass ratio of 100:2:0.08 to obtain a stabilizer. The temperature of the first-stage silicon carbide microchannel reactor is set at 13.0 °C, the feeding rate of tetramethoxysiloxane is set at 2.0 ml / min, the feeding rate of the dispersion liquid is set at 12.8 ml / min, the temperature of the second-stage silicon carbide microchannel reactor is set at 77 °C, the feeding rate of the acidic hydrolysis solution is set at 18.1 ml / min, the temperature of the third-stage silicon carbide microchannel reactor is set at 23 °C, and the feeding rate of the stabilizer is set at 0.4 ml / min. When the temperature reaches, turn on the pumps of the first stage, the second stage and the third stage in sequence to start the reaction. When the reaction temperature fluctuations of the first-stage, second-stage and third-stage silicon carbide microchannel reactors are less than 0.8 °C, high-purity spherical silica sol with a particle size of 118 nm is obtained from the outlet of the third-stage silicon carbide microchannel reactor. The high-purity spherical silica sol produced by the third-stage silicon carbide microchannel reactor is collected in a reaction kettle and heated to 100 °C. At the same time, ultrapure water is added to maintain a constant liquid level. When the alcohol content is detected to be less than 0.1 g / L, the solvent replacement is completed. The high-purity spherical silica sol after solvent replacement is concentrated through a membrane filter to a silica content of 28% to obtain an ultrapure silica sol with a total metal ion content of 0.4 ppm, and its particle morphology is spherical, as Figure 4 shown.

[0038] According to another embodiment of the present invention, a high-purity spherical silica sol for electronic polishing is also disclosed. The high-purity spherical silica sol for electronic polishing is prepared by the preparation method of the high-purity spherical silica sol for electronic polishing disclosed in any of the above embodiments.

[0039] In summary, the above embodiments utilize the advantages of the microchannel reactor and special reaction conditions, can effectively control the speed of the hydrolysis polymerization reaction, solve the problem that the speed of the hydrolysis polymerization reaction of tetramethoxysiloxane is difficult to control, and successfully prepare an ultrapure silica sol with high stability and good uniformity. This method has the advantages of simple operation, a closed reaction process, avoiding air pollution and not volatilizing harmful substances, and can be continuously produced.

[0040] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, 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 method for preparing high-purity spherical silica sol for electronic polishing, characterized in that: include: Simultaneously injecting tetramethoxysiloxane and a dispersion liquid from two feed ports of a first-stage silicon carbide microchannel reactor, wherein the injection rate of tetramethoxysiloxane is 1.5-2.1 ml / min, and the injection rate of the dispersion liquid is 3.0-16.8 ml / min, wherein the dispersion liquid comprises a complex alcohol, ultrapure water and a weak base; performing a hydrolysis polymerization reaction at a temperature of 5-15° C., controlling the temperature fluctuation during the reaction process within 1.2° C., and obtaining a solution A from the outlet of the first-stage silicon carbide microchannel reactor; The outlet of the first-stage silicon carbide microchannel reactor is connected to the second-stage silicon carbide microchannel reactor, and the A solution and the acidic hydrolyzate are simultaneously injected from two feed ports of the second-stage silicon carbide microchannel reactor, and the injection rate of the acidic hydrolyzate is 9.0-95.0 ml / min; the acidic hydrolyzate comprises tetramethoxysiloxane, ultrapure water and acid, and the pH value is 2-4; a particle homogenization reaction is performed at a temperature of 50-85° C., and a B solution is obtained from the outlet of the second-stage silicon carbide microchannel reactor; The outlet of the second-stage silicon carbide microchannel reactor is connected to the third-stage silicon carbide microchannel reactor, and the B solution and the stabilizer are simultaneously injected from the two feed ports of the third-stage silicon carbide microchannel reactor, and the injection rate of the stabilizer is 0.01-9.1 ml / min; the stabilizer includes ultrapure water, an organic base and a viscosity reducer; a particle stability reaction is carried out at a temperature of 20-30° C., and a high-purity spherical silica sol is obtained from the outlet of the third-stage silicon carbide microchannel reactor, wherein the mass ratio of the B solution to the stabilizer is 100:1-8; the mass ratio of the ultrapure water, the organic base and the viscosity reducer in the stabilizer is 100:2-6:0.05-0.1, and the viscosity reducer includes polyethylene glycol and / or nonylphenol.

2. The method for preparing high-purity spherical silica sol for electronic polishing according to claim 1, characterized in that: Also includes: The high-purity spherical silica sol prepared by the third-stage silicon carbide microchannel reactor is collected into a reaction kettle, heated to 100° C. and ultrapure water is added to maintain a constant liquid level to perform solvent replacement; The high-purity spherical silica sol after solvent replacement is concentrated through a membrane filter to a silicon dioxide content greater than 20%, thereby obtaining an ultra-high-purity spherical silica sol with a total metal ion content less than 1 ppm.

3. The method for preparing high-purity spherical silica sol for electronic polishing according to claim 1, characterized in that: The mass ratio of tetramethoxysiloxane to the dispersion is 1:2-8; the mass ratio of the complex alcohol, ultrapure water and weak base in the dispersion is 10:1.3-1.8:0.1-0.

5.

4. The method for preparing high-purity spherical silica sol for electronic polishing according to claim 3, characterized in that: The complex alcohol is a mixture of two or more of isopropanol, methanol and ethanol; the weak base is a mixture of two or more of ammonia water, monoethanolamine, diethanolamine, triethanolamine and ethylenediamine.

5. The method for preparing high-purity spherical silica sol for electronic polishing according to claim 1, characterized in that: The mass ratio of solution A to the acidic hydrolyzate is 1:3-5; the mass ratio of tetramethoxysiloxane, ultrapure water and acid in the acidic hydrolyzate is 1:2-5:0.01-0.

001.

6. The method for preparing high-purity spherical silica sol for electronic polishing according to claim 1, characterized in that: The acid includes one or a mixture of more than one of sulfuric acid, hydrochloric acid, nitric acid, oxalic acid, citric acid and acetic acid.

7. The method for preparing high-purity spherical silica sol for electronic polishing according to claim 6, characterized in that: The organic base includes ethylenediamine and / or tetramethylammonium hydroxide.

8. The method for preparing high-purity spherical silica sol for electronic polishing according to any one of claims 1 to 7, characterized in that: The total ion content of the sodium ion, aluminum ion, copper ion, iron ion, calcium ion, magnesium ion and potassium ion in the tetramethoxysiloxane, the complex alcohol, the weak base, the acid, the organic base and the viscosity reducer used in the reaction process is less than 1 ppb.

9. The method for preparing high-purity spherical silica sol for electronic polishing according to any one of claims 1 to 7, characterized in that: The pumps, pipelines, valves and storage tanks that contact the materials during the reaction process are all made of non-metallic materials. The first-stage silicon carbide microchannel reactor, the second-stage silicon carbide microchannel reactor and the third-stage silicon carbide microchannel reactor are sealed and connected to form a closed reaction environment.

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