Alkali-resistant spherical silica slurry for packaging substrates and method for producing same

Abstract

The present invention provides an alkali-resistant spherical silica slurry for packaging substrates and a method for producing the same. In this production method, submicron spherical silica and micron spherical silica are first blended, and then the blended spherical silica A is wet-modified using a silane coupling agent. Secondary modification is then performed using a non-polar short-chain silane coupling agent. Finally, the modified silica is dispersed in an organic solvent and classified to obtain a spherical silica slurry. The spherical silica slurry produced by this method has good stability, reasonable product particle size distribution, and uniform modifier coating. When applied to packaging substrates, it has good alkali resistance, good fluidity, and low melt viscosity.

Description

[Technical Field]

[0001] This application claims priority to a Chinese patent application filed with the China Patent Office on December 22, 2023, bearing application number CN202311782512.3 and entitled "Alkali-resistant spherical silica slurry for packaging substrates and method for producing the same," the entire contents of which are incorporated herein by reference.

[0002] The present application belongs to the technical field of inorganic fillers, and relates to an alkali-resistant spherical silica slurry for package substrates and a method for producing the same. [Background technology]

[0003] Package substrates, also known as IC substrates, are an important material for connecting chips to PCB motherboards in IC packages, and have now replaced traditional lead frames in mid- to high-end packaging. The main functions of IC substrates include chip protection, support, and heat dissipation. IC substrates are similar to PCBs in terms of structure and function, and evolved from HDI substrates. However, the technical hurdles for IC substrates are much higher than those for HDI and ordinary PCBs. They feature high density, high precision, multiple pin counts, high performance, miniaturization, and thinness, and have higher requirements for various technical parameters such as line width and line spacing.

[0004] Package substrates not only have high requirements for CTE (coefficient of thermal expansion) and are required to have high fluidity, but also particularly require good bonding strength between the filler and resin, good alkali resistance, and low surface roughness after Desmear processing (removing glue residue during drilling).Poor alkali resistance can result in increased roughness after Desmear processing, potentially causing problems with the long-term reliability of interlayer insulation.

[0005] Patent Document 1 discloses a silica slurry composition, which is prepared by coating the surface of silica fine powder with nano-scale silica and dispersing it in an organic solvent, and the resulting silica slurry composition is used for laminates and has excellent dispersibility and fluidity. However, the addition of nano-spherical silicon oxide does not improve alkali resistance.

[0006] Patent Document 2 discloses a slurry composition, which is a technology for producing a silica slurry composition by using a plasma modification method to coat the surface of silica with a single layer of a weakly polar or non-polar monomer and dispersing it in an organic solvent. The composition has good dispersibility, fluidity, and dielectric properties, and also has good sedimentation stability due to the uniform coating of the modifier. However, the plasma modification used in this method is difficult to produce industrially. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Chinese Patent No. 106700132 [Patent Document 2] Chinese Patent Application Publication No. 109021292 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide an alkali-resistant spherical silica slurry for packaging substrates and a method for producing the same. [Means for solving the problem]

[0009] The technical solution to achieve the object of the present invention is as follows. The method for producing alkali-resistant spherical silica slurry for packaging substrates includes the following steps: (1) Composition of raw materials: D50=0.3~0.8μm, D100≦5.0μm, SSA=4.0~12.0m2 / g submicron spherical silica, D50=1.0~3.0μm, D100≦5.0μm, SSA=0.5~4.0m 2 / g of micron spherical silica was mixed in a mass ratio of 1:3 to 3:1, and D50=0.4 to 2.0 μm, D100≦5.0 μm, SSA=1.5 to 9.0 m 2 / g of spherical silica A is obtained. (2) Wet modification: The spherical silica A and water are uniformly mixed in a mass ratio of 3:7 to 6:4 and pre-dispersed to obtain a submicron slurry. A modifier is then added and initial modification is performed by wet polishing. The initially modified slurry is then dry-modified at 120 to 300°C until the moisture content is 0.3% or less, and then kept at 60 to 120°C. Finally, the material after keeping is depolymerized until the particle size matches that of spherical silica A to obtain wet-modified spherical silica B. The modifier is selected from an epoxy-based silane coupling agent, an anilino-based silane coupling agent, an isocyanate-based silane coupling agent, or a ureido-based silane coupling agent. (3) Secondary modification: The wet-modified spherical silica B is subjected to secondary modification using a non-polar short-chain silane coupling agent to obtain secondarily modified spherical silica C, and the non-polar short-chain silane coupling agent is a short-chain alkyl silane coupling agent or a silazane. (4) Slurrying: The spherical silica C after the secondary modification is pre-dispersed in an organic solvent while stirring, then dispersed using a disperser, and then particles having a predetermined particle size or larger are removed by classification to obtain an alkali-resistant spherical silica slurry for packaging substrates, where the organic solvent is acetone, butanone, methyl isobutyl ketone (MIBK), or cyclohexanone.

[0010] Preferably, in step (2), the pre-dispersion is carried out using a sand mill, and the temperature of the pre-dispersion is 50 to 90°C.

[0011] Preferably, in step (2), the incubation time is 20 to 60 minutes.

[0012] Preferably, in step (2), the depolymerization is carried out using an airflow pulverizer, and the depolymerization pressure is 1.0 MPa or more.

[0013] Preferably, in step (2), the mass ratio of the modifier to the spherical silica A is 0.1-2.0:100.

[0014] Preferably, in step (2), the epoxy group silane coupling agent is 3-glycidylpropyltrimethoxysilane, the anilino group silane coupling agent is N-phenyl-3-aminopropyltrimethoxysilane, the isocyanate group silane coupling agent is 3-isocyanatopropyltriethoxysilane, and the ureido group silane coupling agent is 3-ureidopropyltriethoxysilane.

[0015] Preferably, in step (3), the short-chain alkyl silane coupling agent is selected from methyltrimethoxysilane, methyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, dimethyldimethoxysilane, or trimethylmethoxysilane, and the silazane is hexamethyldisilazane or tetramethyldisilazane.

[0016] Preferably, in step (3), the mass ratio of the non-polar short-chain silane coupling agent to the spherical silica B is 0.1-1.0:100.

[0017] Preferably, in step (3), the device used for the secondary reforming is a high-speed agitator, the temperature in the secondary reforming is 80 to 150°C, and the time for the secondary reforming is 10 to 40 minutes.

[0018] Preferably, in step (4), the mass ratio of the spherical silica C to the organic solvent is 25:75 to 50:50.

[0019] Preferably, in step (4), a high-pressure homogenizer is used as the dispersing machine, the dispersion pressure is 10,000 psi to 20,000 psi, the device used for classification is a wet vibrating sieve, the sieve mesh size of the wet vibrating sieve is 10 μm or less, and the device used for drying and modifying is a flash dryer.

[0020] The alkali-resistant spherical silica slurry for packaging substrates is manufactured by the manufacturing method described in the above technical proposal. [Effects of the Invention]

[0021] Compared with the prior art, the present invention has the following advantages: (1) In the method of the present invention, submicron spherical silica is blended with micron spherical silica, which has a small specific surface area and a narrow particle size distribution. Because the micron spherical silica has a small specific surface area, there is little interfacial contact with the resin during use. In addition, by combining spheres of different sizes, alkali resistance can be improved and the surface roughness after Desmear treatment is also reduced.

[0022] (2) In the method of the present invention, wet modification is performed using a polar silane coupling agent to achieve a uniform coating of the modifier, followed by secondary modification using a short-chain silane. The presence of polar groups improves compatibility between the filler (silica) and the resin, while the presence of nonpolar groups improves the dispersibility of the filler (silica). This results in good alkali resistance during use and low surface roughness after Desmear treatment. Furthermore, the synergistic effect of the silane coupling agent and the nonpolar short-chain silane can further improve the stability and flowability of the product.

[0023] (3) The spherical silica slurry product produced in this application has good stability. When applied to packaging substrates, it has good alkali resistance and low surface roughness after desmearing. At the same time, the manufacturing process is easy to control, the product has good stability, and is suitable for mass production. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present application will be described in more detail below in conjunction with specific examples. The methods for measuring D50, D100, pH, weight loss by TGA (thermogravimetric analysis), viscosity, and flow time of the silica fine powder in the following examples and comparative examples are as follows. (1) Measurement of D50 and D100: Measured using a Beckman Coulter LS13320 laser particle size distribution analyzer. (2) Sedimentation stability: Fill a 100 ml test tube with the slurry up to the 100 ml mark, seal it, and store it at room temperature. After one month, observe the layer separation of the slurry, record the height of the clear liquid that has separated into layers, and turn the tube upside down to observe whether there is any sedimentation at the bottom. The less layer separation and sedimentation at the bottom, the better the stability of the product. (3) Melt viscosity measurement: When the product is used in the formulation of a carrier substrate, the rheology curve of the semi-cured resin powder is measured within the range of 80 to 190°C, and the minimum melt viscosity (η) is confirmed. The smaller the minimum melt viscosity, the better the fluidity.

[0025] [Example 1] (1) Composition of raw materials D50=0.50μm, D100=2.6μm, SSA=6.6m 2 / g submicron spherical silica, D50=1.5μm, D100=2.2μm, SSA=2.6m 2 / g of micron spherical silica was mixed in a mass ratio of 1:1, and D50 = 0.93 μm, D100 = 2.6 μm, SSA = 4.6 m 2 / g of spherical silica A was obtained. (2) Wet modification Spherical silica A and deionized water were mixed uniformly at a mass ratio of 1:1, then sent to a sand mill for pre-dispersion. The temperature of the pre-dispersion was controlled at 80°C, and a submicron slurry was obtained. Then, 0.6% of N-phenyl-3-aminopropyltrimethoxysilane KBM-573 (Shin-Etsu Chemical) was added to the mass of spherical silica A, and initial modification was performed by wet grinding. The initially modified slurry was then sent to a flash dryer for drying and modification. The air temperature was 250°C, and the mixture was dried until the moisture content was 0.3% or less. After that, the mixture was sent to a collector for heat retention at 110°C for 30 minutes. The material after heat retention was then depolymerized in an airflow mill at a depolymerization pressure of 1.0 MPa to obtain wet-modified spherical silica B. (3) Secondary modification Spherical silica B was placed in a high-speed mixer, and methyltrimethoxysilane KBM-13 (Shin-Etsu Chemical) was added at the same time. Modification was carried out at 100°C for 20 minutes to obtain secondary-modified spherical silica C. The mass ratio of methyltrimethoxysilane KBM-13 to spherical silica B was 0.3:100. (4) Slurrying Spherical silica C and the organic solvent acetone were placed in a stirring tank in a mass ratio of 7:3 and pre-dispersed. After that, the mixture was dispersed using a homogenizer under a pressure of 10,000 psi. Large particles were then sieved out using a sieve with pores of 5 μm to remove them, yielding an alkali-resistant spherical silica slurry for packaging substrates.

[0026] [Example 2] (1) Composition of raw materials D50=0.78μm, D100=3.5μm, SSA=5.2m 2 / g submicron spherical silica, D50=2.0μm, D100=3.5μm, SSA=1.8m 2 / g of micron spherical silica was mixed in a mass ratio of 1:2, and D50 = 1.2 μm, D100 = 3.5 μm, SSA = 4.8 m 2 / g of spherical silica A was obtained. (2) Wet modification Spherical silica A and deionized water were mixed uniformly in a mass ratio of 6:4, then sent to a sand mill for pre-dispersion. The temperature of the pre-dispersion was controlled at 60°C, and after uniform dispersion, a submicron slurry was obtained. 0.8% of 3-glycidylpropyltrimethoxysilane KBM-403 (Shin-Etsu Chemical) was then added to the mass of spherical silica A, and initial modification was performed by wet grinding. The initially modified slurry was then sent to a flash dryer for drying and modification, with the air temperature at 150°C, until the moisture content was 0.3% or less. After that, the slurry was sent to a collector for heat retention at 100°C for 60 minutes. The material after heat retention was then depolymerized in an airflow mill at a depolymerization pressure of 1.0 MPa, to obtain wet-modified spherical silica B. (3) Secondary modification Spherical silica B was placed in a high-speed mixer, and dimethyldimethoxysilane KBM-22 (Shin-Etsu Chemical) was added at the same time. Modification was carried out at 100°C for 20 minutes to obtain secondary-modified spherical silica C. The mass ratio of dimethyldimethoxysilane KBM-22 to spherical silica B was 0.3:100. (4) Slurrying Spherical silica C and the organic solvent butanone were placed in a stirring tank in a mass ratio of 7:3 and pre-dispersed. After that, the mixture was dispersed using a homogenizer under a pressure of 10,000 psi. Next, large particles were removed by sieving using a sieve with 10 μm pore size, yielding an alkali-resistant spherical silica slurry for packaging substrates.

[0027] [Example 3] (1) Composition of raw materials D50=0.36μm, D100=0.87μm, SSA=11.6m 2 / g submicron spherical silica, D50=1.1μm, D100=2.0μm, SSA=3.2m 2 / g of micron spherical silica was mixed in a mass ratio of 1:2, and D50 = 0.59 μm, D100 = 2.0 μm, SSA = 6.0 m 2 / g of spherical silica A was obtained. (2) Wet modification Spherical silica A and deionized water were mixed uniformly in a mass ratio of 4:6, then sent to a sand mill for pre-dispersion. The temperature of the pre-dispersion was controlled at 60°C, and after uniform dispersion, a submicron slurry was obtained. 2.0% of 3-ureidopropyltriethoxysilane KBE-585 (Shin-Etsu Chemical) was then added to the spherical silica A mass, and initial modification was performed by wet grinding. The initially modified slurry was then sent to a flash dryer for drying and modification, with the air temperature at 220°C, until the moisture content was 0.3% or less. After that, the slurry was sent to a collector for heat retention at 120°C for 30 minutes. The material after heat retention was then depolymerized in an airflow mill at a depolymerization pressure of 1.0 MPa, to obtain wet-modified spherical silica B. (3) Secondary modification Spherical silica B was placed in a high-speed mixer, and hexamethyldisilazane SZ-13 (Shin-Etsu Chemical) was added at the same time. Modification was carried out at 110°C for 20 minutes to obtain secondary-modified spherical silica C. The mass ratio of hexamethyldisilazane SZ-13 to spherical silica B was 0.8:100. (4) Slurrying Spherical silica C and the organic solvent butanone were placed in a stirring tank in a mass ratio of 7:3 and pre-dispersed. After that, the mixture was dispersed using a homogenizer under a pressure of 10,000 psi. Next, large particles were removed by sieving using a sieve with pores of 5 μm, yielding an alkali-resistant spherical silica slurry for packaging substrates.

[0028] [Example 4] (1) Composition of raw materials D50=0.50μm, D100=2.6μm, SSA=6.6m 2 / g submicron spherical silica, D50=1.5μm, D100=2.2μm, SSA=2.6m 2 / g of micron spherical silica was mixed in a mass ratio of 1:1, and D50 = 0.93 μm, D100 = 2.6 μm, SSA = 4.6 m 2 / g of spherical silica A was obtained. (2) Wet modification After uniformly mixing spherical silica A and deionized water in a mass ratio of 3:7, the mixture was sent to a sand mill for pre-dispersion. The temperature of the pre-dispersion was controlled at 70°C. After uniform dispersion, a submicron slurry was obtained. 1.0% of 3-isocyanatopropyltriethoxysilane KBE-9007N (Shin-Etsu Chemical) was then added to the spherical silica A mass, and the mixture was modified by wet grinding to complete the initial modification. The initially modified slurry was then sent to a flash dryer for drying at an air temperature of 180°C until the moisture content was reduced to 0.3% or less. The mixture was then sent to a collector for heat retention at 100°C for 60 minutes. The material after heat retention was then depolymerized in an airflow mill at a depolymerization pressure of 1.0 MPa to obtain wet-modified spherical silica B. (3) Secondary modification Spherical silica B was placed in a high-speed mixer, and methyltrimethoxysilane KBM-13 (Shin-Etsu Chemical) was added at the same time. Modification was carried out at 100°C for 20 minutes to obtain secondary-modified spherical silica C. The mass ratio of methyltrimethoxysilane KBM-13 to spherical silica B was 0.5:100. (4) Slurrying Spherical silica C and the organic solvent methyl isobutyl ketone (MIBK) were placed in a stirring tank in a mass ratio of 7:3 and pre-dispersed. After that, the mixture was dispersed using a homogenizer under a pressure of 10,000 psi. Next, large particles were removed by sieving using a sieve with pores of 5 μm, yielding an alkali-resistant spherical silica slurry for packaging substrates.

[0029] [Comparative Example 1] This comparative example was similar to Example 1, except for the dry modification in step (2). Specifically, spherical silica A was placed in a high-speed mixer and stirred, while 0.6% of an anilino-silane coupling agent, KBM-573 (Shin-Etsu Chemical Co., Ltd.), was added. The mixture was modified at 110°C for 30 minutes to obtain spherical silica B.

[0030] Comparative Example 2 This comparative example is substantially the same as Example 1, except that micron-spherical silica is not added in step (1).

[0031] Comparative Example 3 This comparative example is substantially the same as Example 1, except that the silane coupling agent in step (2) is vinyltrimethoxysilane KBM-1003.

[0032] Comparative Example 4 This comparative example is substantially the same as Example 1, except that step (3) is not performed.

[0033] Comparative Example 5 This comparative example was substantially the same as Example 1, except that the silane coupling agent in step (3) was decyltrimethoxysilane KBM-3103 (Shin-Etsu Chemical).

[0034] The stability of the silica slurries prepared in the examples and comparative examples was examined and the results are shown in Table 1.

[0035] Sedimentation results of silica slurries produced in Examples and Comparative Examples [Table 1]

[0036] As can be seen from Table 1, after leaving the slurry for one month, Examples 1 to 4 showed low layer separation heights and no sediment at the bottom even when inverted, indicating good stability of the slurry products of the Examples. Comparative Example 1 differs from Example 1 in the modification process in step (2): Example 1 employs wet modification, while Comparative Example 1 employs dry modification. Comparative Example 1 showed higher layer separation heights and sediment at the bottom, indicating that wet modification helps improve sedimentation stability. Comparative Example 2 did not incorporate micron-spherical silica into the raw material, compared to Example 1. Comparative Example 2 showed slightly lower layer separation heights and no sediment at the bottom, indicating good slurry product stability. This indicates that the addition of micron-spherical silica is detrimental to sedimentation stability, but the effect is not significant. Comparative Example 3 differs from Example 1 in the type of modifier used in step (2). However, the layer separation height of Comparative Example 3 is similar to that of Example 1, there is no sediment at the bottom, and the stability of the slurry product is still good, indicating that the type of modifier used in step (2) does not significantly affect the stability of the slurry product. Comparative Example 4 does not include step (3) compared to Example 1, but the layer separation height of the slurry product is high and there is sediment at the bottom, indicating that step (3) can improve sedimentation stability. Comparative Example 5 differs from Example 1 in the modifier used. Comparative Example 5 uses a long-chain alkylsilane, KBM-3103. The layer separation height of the slurry product of Comparative Example 5 is high and there is sediment at the bottom, indicating that the chain length of the alkylsilane used in step (3) affects the stability of the product.

[0037] SC2050MT, a slurry product from an advanced overseas competitor * The slurry products of the examples and comparative examples were used to formulate BT resin packaging substrates, with a filler ratio of 65%. The melt viscosity of the product and the weight loss rate of the plate after desmearing were measured. The smaller the weight loss rate after desmearing, the less rough the plate surface after desmearing and the better its alkali resistance. The melt viscosity of the product and the weight loss rate of the plate after desmearing are shown in Table 2.

[0038] Melt viscosity of package substrates manufactured in Examples and Comparative Examples and weight loss rate after desmearing of the plate material [Table 2]

[0039] As can be seen from Table 2, the minimum melt viscosity of the examples is SC2050MT * The weight loss rate after desmearing is close to that of SC2050MT. * The results are lower than those of Example 1, indicating that the fluidity of the product of the present application is closer to that of products from overseas competitors and that its alkali resistance is better than that of products from overseas competitors. Comparative Example 1 differs from Example 1 in the modification process in step (2). Example 1 employs wet modification, while Comparative Example 1 employs dry modification. The large weight loss rate and melt viscosity after desmearing in Comparative Example 1 indicate that the wet modification employed in the present application results in good alkali resistance and low melt viscosity. Comparative Example 1 does not incorporate micronized spherical silica into the raw materials compared to Example 2. However, the large weight loss rate and melt viscosity after desmearing in Comparative Example 2 indicate that the addition of micronized spherical silica can improve alkali resistance and melt viscosity. Comparative Example 3 differs from Example 1 in the type of modifier in step (2). Comparative Example 3 also exhibits a large weight loss rate and melt viscosity after desmearing, indicating that the type of modifier in step (2) affects the alkali resistance and melt viscosity of the slurry product. Compared to Example 1, Comparative Example 4 does not include step (3). However, the product of Comparative Example 4 had a large weight loss rate after desmearing and a large melt viscosity, indicating that step (3) can improve alkali resistance and melt viscosity. Compared to Example 1, Comparative Example 5 used a different modifier, the long-chain alkylsilane KBM-3103. However, the slurry product of Comparative Example 5 had a slightly larger weight loss rate after desmearing and a large melt viscosity, indicating that the chain length of the alkylsilane in step (3) affects the alkali resistance and melt viscosity of the product.

[0040] Although the above embodiments provide detailed descriptions of the present application, they are only some of the embodiments of the present application and do not cover all of the embodiments. Based on these embodiments, people can obtain other embodiments without any creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A method for producing an alkali-resistant spherical silica slurry for a packaging substrate, comprising the following steps: (1) Composition of raw materials: D50=0.3~0.8μm, D100≦5.0μm, SSA=4.0~12.0m ２ / g submicron spherical silica, D50 = 1.0 to 3.0 μm, D100 ≦ 5.0 μm, SSA = 0.5 to 4.0 m ２ / g of micron spherical silica was mixed in a mass ratio of 1:3 to 3:1, and D50=0.4 to 2.0 μm, D100≦5.0 μm, SSA=1.5 to 9.0 m ２ / g of spherical silica A was obtained, (2) Wet modification: The spherical silica A and water are uniformly mixed in a mass ratio of 3:7 to 6:4 and pre-dispersed to obtain a submicron slurry, and then a modifier is added and initial modification is performed by wet polishing. The initially modified slurry is then dried at 120 to 300°C until the moisture content is 0.3% or less, and then kept at 60 to 120°C. Finally, the material after keeping is depolymerized until the particle size matches that of the spherical silica A to obtain wet-modified spherical silica B, and the modifier is selected from an epoxy group silane coupling agent, an anilino group silane coupling agent, an isocyanate group silane coupling agent, or a ureido group silane coupling agent. (3) Secondary modification: the wet-modified spherical silica (B) is subjected to a second modification using a non-polar short-chain silane coupling agent to obtain a second-modified spherical silica (C), and the non-polar short-chain silane coupling agent is a short-chain alkyl silane coupling agent or a silazane; (4) Slurrying: The spherical silica C after the second modification is preliminarily dispersed in an organic solvent while stirring, then dispersed in a disperser, and then particles having a predetermined particle size or larger are removed by classification to obtain an alkali-resistant spherical silica slurry for packaging substrates, wherein the organic solvent is acetone, butanone, methyl isobutyl ketone, or cyclohexanone. A manufacturing method comprising:

2. The method according to claim 1, wherein in step (2), the pre-dispersion is performed using a sand mill, the temperature of the pre-dispersion is 50 to 90°C, the warming time is 20 to 60 minutes, and the depolymerization is performed using an airflow pulverizer, and the depolymerization pressure is 1.0 MPa or more.

3. 2. The method according to claim 1, wherein in step (2), the mass ratio of the modifier to the spherical silica A is 0.1-2.0:

100.

4. The manufacturing method according to claim 1, wherein in step (2), the epoxy group silane coupling agent is 3-glycidylpropyltrimethoxysilane, the anilino group silane coupling agent is N-phenyl-3-aminopropyltrimethoxysilane, the isocyanate group silane coupling agent is 3-isocyanatopropyltriethoxysilane, and the ureido group silane coupling agent is 3-ureidopropyltriethoxysilane.

5. 2. The method of claim 1, wherein in step (3), the short-chain alkyl silane coupling agent is selected from methyltrimethoxysilane, methyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, dimethyldimethoxysilane, or trimethylmethoxysilane, and the silazane is hexamethyldisilazane or tetramethyldisilazane.

6. 2. The method according to claim 1, wherein in step (3), the mass ratio of the non-polar short-chain silane coupling agent to the spherical silica B is 0.1-1.0:

100.

7. 2. The method according to claim 1, wherein in step (3), the apparatus used for the secondary reforming is a high-speed agitator, the temperature in the secondary reforming is 80 to 150°C, and the time for the secondary reforming is 10 to 40 minutes.

8. 2. The method according to claim 1, wherein in step (4), the mass ratio of the spherical silica C to the organic solvent is 25:75 to 50:

50.

9. The method according to claim 1, wherein in step (4), a high-pressure homogenizer is used as the disperser, the dispersion pressure is 10,000 psi to 20,000 psi, the classification device is a wet vibrating sieve, the sieve mesh size of the wet vibrating sieve is 10 μm or less, and the drying modification device is a flash dryer.

10. An alkali-resistant spherical silica slurry for packaging substrates, produced by the method according to any one of claims 1 to 9.

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