A method for modifying inorganic powder, modified inorganic powder and carrier plate insulation adhesive film

Abstract

This invention provides a method for modifying inorganic powder, modified inorganic powder, and a carrier insulating film. The modification method includes the following steps: (1) drying the inorganic powder; (2) mixing a silane coupling agent with an alcohol solvent, adding deionized water while stirring, and continuing to stir to obtain a silane hydrolysate; (3) spraying the silane hydrolysate obtained in step (2) onto the inorganic powder obtained in step (1) while it is being stirred, heating, and stirring to react, thereby obtaining the modified inorganic powder. The modification method provided by this invention constructs a dense organic molecular layer on the surface of the inorganic powder that is chemically compatible with the resin matrix through a stepwise and controllable process, thereby significantly improving the dispersibility of the inorganic powder in the resin, reducing the viscosity of the slurry, and enhancing the dielectric properties and reliability of the final composite material.

Description

Technical Field

[0001] This invention belongs to the field of encapsulation substrate technology, and relates to a method for modifying inorganic powder, modified inorganic powder, and substrate insulating film. Background Technology

[0002] Integrated circuit packaging substrates (hereinafter referred to as "substrates") are key components connecting chips to printed circuit boards (PCBs), playing a role in physical support, electrical connection, heat dissipation, and chip protection. With the development of electronic products towards high performance, miniaturization, and high density, unprecedented demands are placed on the wiring density, signal transmission speed, reliability, and heat dissipation performance of substrates. Insulating films, especially resin-based composite films composed of epoxy resin, polyimide, and benzoxazine, are one of the core basic materials for manufacturing substrates. As interlayer dielectric layers or bonding sheets, their performance directly determines the insulation reliability, signal transmission loss (especially dielectric properties at high frequencies), thermomechanical stability (such as the coefficient of thermal expansion CTE), and heat resistance (such as the glass transition temperature Tg) of the substrate. To optimize the above-mentioned properties of pure resin films, the industry commonly uses the method of filling the resin matrix with inorganic powders such as silica (SiO2) to prepare composite dielectric materials. However, introducing these inorganic powders into the organic resin matrix faces a fundamental technical challenge: the interfacial compatibility between the inorganic powder and the resin. Inorganic powders have high surface energy and strong hydrophilicity, while organic resins are typically hydrophobic. Their inherent incompatibility leads to poor dispersibility, weak interfacial bonding, and reduced flowability. Therefore, effectively modifying the powder surface to achieve highly uniform dispersion and strong interfacial bonding of inorganic powders in a resin matrix is ​​a key technology for improving the overall performance of insulating films for carrier substrates, and ultimately driving the development of advanced encapsulation technologies.

[0003] Modifying inorganic powders using silane coupling agents is currently the most widely used powder surface modification technology. The principle is to utilize silane coupling agents (whose general formula is Y-(CH2)). n The silanol group (-SiOH) in -Si(OR)3 undergoes a condensation reaction with the hydroxyl group (-OH) on the surface of the inorganic powder. At the same time, its organic functional group Y (such as amino, epoxy, vinyl, etc.) undergoes a chemical reaction or physical entanglement with the resin matrix, thereby forming a "bridge" between the inorganic powder and the resin, thus improving the compatibility of the inorganic powder and the organic resin system. For example, CN110845872A discloses a method for modifying highly dispersible nano silica, which describes in detail the process of wet modification of nano SiO2 using silane coupling agents.

[0004] In summary, in high-density integrated circuit packaging, the substrate insulating film needs to possess characteristics such as low dielectric constant, low dielectric loss, low coefficient of thermal expansion, and high reliability. Adding a large amount of silica powder to the resin matrix (such as epoxy resin) is a key technical means to reduce the dielectric constant of the material and adjust the coefficient of thermal expansion. However, nano- or micro-sized silica powder has high surface energy and strong hydrophilicity, and is very easy to agglomerate in organic resin, leading to the following problems: (1) stress concentration points are formed in the film, becoming weak links in electrical and mechanical properties; (2) the viscosity of the slurry increases sharply, the leveling property deteriorates, and the coating process under high filling amount becomes difficult; (3) the bonding force between the filler and the resin interface is weak, and it is easy to adsorb water vapor, which leads to increased dielectric loss under high frequency conditions and affects the long-term moisture and heat resistance reliability of the packaging structure.

[0005] Existing powder modification methods mostly employ simple silane coupling agent solutions, but these methods suffer from problems such as insufficient hydrolysis of the coupling agent, low reaction efficiency with the powder surface, and uneven coating, making it difficult to meet the extremely high requirements for interface stability under demanding high-frequency applications.

[0006] Therefore, developing a method that can achieve uniform, firm, and efficient modification of the surface of inorganic powders is crucial for the preparation of high-performance carrier insulating films. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a method for modifying inorganic powders, modified inorganic powders, and a carrier insulating film. Specifically, it provides a method for modifying inorganic powders for use in carrier insulating films, allowing the selection of inorganic powders with low coefficients of thermal expansion, low dielectric properties, or high thermal conductivity. The modification method provided by this invention, through a step-by-step, controllable process, constructs a dense organic molecular layer on the surface of the inorganic powder that is chemically compatible with the resin matrix. This significantly improves the dispersibility of the inorganic powder in the resin, reduces the viscosity of the slurry, and enhances the dielectric properties and reliability of the final composite material.

[0008] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for modifying inorganic powders, the method comprising the following steps: (1) Dry the inorganic powder to remove physically adsorbed water and activate the hydroxyl groups on the surface of the inorganic powder; (2) Mix the silane coupling agent with an alcohol solvent, add deionized water while stirring, and continue stirring to fully hydrolyze the silane coupling agent and obtain a clear silane hydrolysate. (3) The silane hydrolysate obtained in step (2) is sprayed evenly and slowly onto the inorganic powder obtained in step (1) under stirring. After spraying, the temperature is raised and the mixture is stirred to allow the silane hydrolysate to fully undergo a condensation reaction with the hydroxyl groups on the surface of the inorganic powder, thereby obtaining the modified inorganic powder.

[0009] This invention employs a composite surface modification process involving silane coupling agents and polymer grafting to modify inorganic powders. This process significantly improves the interfacial compatibility and bonding strength between inorganic powders and organic resins, solving the technical problems of easy powder agglomeration, high system viscosity, and poor interfacial reliability under high filling conditions. The resulting insulating film has low coefficient of thermal expansion, low dielectric constant, high thermal conductivity, and high reliability, making it particularly suitable for high-end semiconductor packaging substrates.

[0010] The modification method provided by this invention has the following advantages: 1) Stepwise hydrolysis for high efficiency: The silane coupling agent is first pre-hydrolyzed in a solvent to generate silanols with higher reactivity, and then it comes into contact with the surface of the activated inorganic powder. This avoids the problems of incomplete hydrolysis and uneven coating caused by direct hydrolysis and condensation of silanes on the surface of inorganic powder, ensuring the efficiency and uniformity of the modification reaction.

[0011] 2) Spray coating, uniform and dense: The addition of silane hydrolysate by spraying instead of pouring allows the silane hydrolysate to come into full and uniform contact with the inorganic powder in the form of tiny droplets, achieving "one-by-one" coating of inorganic powder particles. This effectively prevents powder agglomeration and coupling agent self-agglomeration caused by local over-wetting, resulting in a denser and stronger organic coating layer.

[0012] 3) Excellent interfacial performance: The inorganic powder modified by this method has organic functional groups (such as epoxy groups and methacryloxy groups) on its surface that can form strong chemical bonds with the resin matrix of the carrier insulating film, which greatly improves the compatibility and bonding force of the inorganic-organic two-phase interface.

[0013] Preferably, the inorganic powder in step (1) includes silica powder.

[0014] Preferably, the silica powder is spherical silica micropowder.

[0015] Preferably, the median particle size D50 of the silica powder is 0.1~5μm, for example 0.1μm, 0.3μm, 0.5μm, 0.8μm, 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, 5μm, etc.

[0016] Preferably, the drying process in step (1) is carried out in a high-speed mixer.

[0017] Preferably, the high-speed mixer has a rotational speed of 500~1000 rpm, such as 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, etc.

[0018] Preferably, the drying temperature in step (1) is 60~80℃, such as 60℃, 65℃, 70℃, 75℃, 80℃, etc., and the drying time is 20~40 minutes, such as 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, etc.

[0019] Preferably, the drying treatment of the inorganic powder in step (1) specifically includes: The inorganic powder is placed in a high-speed mixer at a speed of 500-1000 rpm and stirred at 60-80℃ for 20-40 minutes.

[0020] Preferably, the silane coupling agent in step (2) includes any one or a combination of at least two of phenylsilane, phenylaminosilane, vinylsilane or aminosilane.

[0021] Preferably, the phenylsilane includes N-phenyl-3-aminopropyltrimethoxysilane and / or phenyltrimethoxysilane.

[0022] Preferably, the phenylaminosilane includes phenylaminopropyltrimethoxysilane.

[0023] Preferably, the alcohol solvent in step (2) includes ethanol and / or isopropanol.

[0024] Preferably, the mass ratio of the silane coupling agent to the alcohol solvent in step (2) is 1:(5~20), for example, 1:5, 1:6, 1:8, 1:10, 1:12, 1:13, 1:14, 1:15, 1:16, 1:18, 1:20, etc.

[0025] Preferably, the amount of deionized water added in step (2) is 1.5 to 2.5 times the amount of water required for the complete hydrolysis of the silane coupling agent, for example, 1.5 times, 1.6 times, 1.8 times, 2 times, 2.2 times, 2.3 times, 2.5 times, etc.

[0026] Preferably, the amount of silane coupling agent used in step (2) is 0.5% to 5% of the mass of the inorganic powder in step (1), for example, 0.5%, 0.6%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.

[0027] Preferably, the continuous stirring in step (2) is carried out at 20~40℃ (e.g., 20℃, 25℃, 30℃, 35℃, 40℃, etc.).

[0028] Preferably, the continuous stirring time in step (2) is 0.5 to 2 hours, for example, 0.5 hours, 1 hour, 1.5 hours, 2 hours, etc.

[0029] Preferably, the spraying in step (3) is achieved by a spraying device.

[0030] Preferably, the temperature rise in step (3) is to rise to 80~110℃, such as 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, etc.

[0031] Preferably, the stirring speed in step (3) is 500~1000 rpm, for example, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, etc.

[0032] Preferably, the stirring reaction time in step (3) is 1 to 3 hours, for example, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, etc.

[0033] As a preferred embodiment of the present invention, the modification method includes the following steps: (1) Place the inorganic powder in a high-speed mixer with a speed of 500~1000 rpm and stir at 60~80℃ for 20~40 minutes; (2) Mix the silane coupling agent with an alcohol solvent, add deionized water while stirring, and continue stirring at 20~40℃ for 0.5~2 hours to obtain a silane hydrolysate; (3) The silane hydrolysate obtained in step (2) is sprayed into the inorganic powder obtained in step (1) under stirring through a spraying device. After spraying, the temperature is raised to 80~110℃, and the temperature is maintained and stirred at a speed of 500~1000 rpm for 1~3 hours to obtain the modified inorganic powder.

[0034] In a second aspect, the present invention provides a modified inorganic powder, which is prepared by the modification method described in the first aspect.

[0035] The modified inorganic powder prepared by the modification method provided in this invention has the following characteristics: Excellent dispersibility: The modified inorganic powder does not agglomerate in the resin slurry, making it easy to achieve high filling.

[0036] Good slurry stability: The slurry obtained from modified inorganic powder has low viscosity and high long-term storage stability, which facilitates coating processing.

[0037] Ultimately, the performance is improved: the prepared insulating film has lower dielectric loss, better moisture resistance, and higher thermomechanical reliability.

[0038] Thirdly, the present invention provides a carrier insulating film, wherein the raw materials for preparing the carrier insulating film include a resin matrix and a filler powder, wherein the filler powder includes the modified inorganic powder as described in the second aspect.

[0039] Preferably, the raw materials for preparing the carrier insulating film also include an initiator.

[0040] Preferably, based on the total weight of the raw materials used to prepare the carrier insulating film as 100%, the content of the filler powder is 70% to 75%, such as 70%, 71%, 72%, 73%, 74%, 75%, etc.

[0041] Compared with the prior art, the present invention has the following beneficial effects: 1) Stepwise hydrolysis for high efficiency: The silane coupling agent is first pre-hydrolyzed in a solvent to generate silanols with higher reactivity, and then it comes into contact with the surface of the activated inorganic powder. This avoids the problems of incomplete hydrolysis and uneven coating caused by direct hydrolysis and condensation of silanes on the surface of inorganic powder, ensuring the efficiency and uniformity of the modification reaction.

[0042] 2) Spray coating, uniform and dense: The addition of silane hydrolysate by spraying instead of pouring allows the silane hydrolysate to come into full and uniform contact with the inorganic powder in the form of tiny droplets, achieving "one-by-one" coating of inorganic powder particles. This effectively prevents powder agglomeration and coupling agent self-agglomeration caused by local over-wetting, resulting in a denser and stronger organic coating layer. Detailed Implementation

[0043] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0044] Example 1 This embodiment provides a method for modifying inorganic powders, the method comprising the following steps: (1) Powder pretreatment: Weigh 500g of spherical silica powder (D50=0.5μm) and place it in a high-speed mixer. Heat it to 70℃ and stir it at 800 rpm for 30 minutes.

[0045] (2) Preparation of hydrolysate: Mix 5 g of N-phenyl-3-aminopropyltrimethoxysilane with 100 g of ethanol, and slowly add deionized water (2.0 times the theoretical amount of water to be hydrolyzed) at 25 °C with stirring. Continue stirring for 1 hour to obtain silane hydrolysate.

[0046] (3) Spray coating reaction: The silane hydrolysate is sprayed evenly onto the preheated powder being stirred at high speed within 20 minutes using a spray device.

[0047] (4) Post-processing: Raise the temperature of the high-speed mixer to 100°C and continue stirring and reacting at a speed of 1000 rpm for 2 hours. Discharge the material to obtain modified inorganic powder, which is denoted as modified powder A.

[0048] Example 2 This embodiment provides a method for modifying inorganic powders, the method comprising the following steps: (1) Powder pretreatment: Same as in Example 1.

[0049] (2) Preparation of hydrolysate: 22.5 g of phenyltrimethoxysilane was mixed with 120 g of isopropanol, and deionized water (1.8 times the theoretical amount of water for hydrolysis) was slowly added dropwise at 35 °C with stirring. The mixture was stirred for 1.5 hours to obtain silane hydrolysate.

[0050] (3) Spray coating reaction: The silane hydrolysate is sprayed evenly onto the preheated powder being stirred at high speed within 25 minutes using a spray device.

[0051] (4) Post-processing: The temperature of the high-speed mixer is raised to 105℃, and the reaction is continued at a speed of 1000 rpm for 1.5 hours. The material is discharged to obtain modified inorganic powder, which is denoted as modified powder B.

[0052] Example 3 This embodiment provides a method for modifying inorganic powders, the method comprising the following steps: (1) Powder pretreatment: Same as in Example 1, the powder is spherical silicon dioxide with D50=1.2μm.

[0053] (2) Preparation of hydrolysate: Mix 5 g of phenylaminopropyltrimethoxysilane with 100 g of ethanol, and slowly add deionized water (2.0 times the theoretical amount of water to be hydrolyzed) at 30 °C with stirring. Continue stirring for 1 hour to obtain silane hydrolysate.

[0054] (3) Spray coating reaction: The silane hydrolysate is sprayed evenly onto the preheated powder being stirred at high speed within 15 minutes using a spray device.

[0055] (4) Post-processing: The temperature of the high-speed mixer is raised to 95°C and stirred at 1000 rpm for 2.5 hours. The material is discharged to obtain modified inorganic powder, which is denoted as modified powder C.

[0056] Example 4 This embodiment provides a method for modifying inorganic powders, the method comprising the following steps: (1) Powder pretreatment: Same as in Example 1, the powder is spherical silicon dioxide with D50=3.5μm.

[0057] (2) Preparation of hydrolysate: 4 g of N-phenyl-3-aminopropyltrimethoxysilane was mixed with 60 g of ethanol, and deionized water (twice the theoretical amount of water for hydrolysis) was slowly added dropwise at 25 °C with stirring. The mixture was stirred for 1.5 hours to obtain silane hydrolysate.

[0058] (3) Spray coating reaction: The silane hydrolysate is sprayed evenly onto the preheated powder being stirred at high speed within 30 minutes using a spray device.

[0059] (4) Post-processing: The temperature of the high-speed mixer is raised to 90°C, and the mixture is stirred and reacted at a speed of 1000 rpm for 3 hours. The mixture is then discharged to obtain modified inorganic powder, which is denoted as modified powder D.

[0060] Comparative Example 1 This comparative example provides a method for modifying inorganic powders, the method comprising the following steps: Weigh 500g of spherical silica powder (D50=0.5μm) and place it in a high-speed mixer. Heat the mixture to 70℃ and stir at 800 rpm for 30 minutes.

[0061] 5 grams of N-phenyl-3-aminopropyltrimethoxysilane (without pre-hydrolysis) were directly poured into the powder being stirred, and mixed for 5 minutes. Then the temperature of the high-speed mixer was raised to 100°C, and stirring was continued at 1000 rpm for 2 hours. The material was then discharged to obtain modified inorganic powder, which was designated as modified powder D1.

[0062] Comparative Example 2 This comparative example provides a method for modifying inorganic powders, the method comprising the following steps: (1) Powder pretreatment: Same as in Example 1, weigh 500g of spherical silica powder and place it in a high-speed mixer, heat it to 70℃, and stir it at 800 rpm for 30 minutes.

[0063] (2) Mixing reaction: 5 g of N-phenyl-3-aminopropyltrimethoxysilane (not pre-hydrolyzed), 100 g of ethanol, and 2.0 times the theoretical hydrolysis water volume of Example 1 were directly mixed evenly and then poured into the preheated powder that was being stirred at high speed. The mixture was mixed for 10 minutes to ensure that the components were in full contact.

[0064] (3) Post-processing: Same as in Example 1, raise the temperature of the high-speed mixer to 100°C, continue stirring and reacting at a speed of 1000 rpm for 2 hours, discharge the material, and obtain modified inorganic powder, which is denoted as modified powder D2.

[0065] Comparative Example 3 This comparative example provides a method for modifying inorganic powders, the method comprising the following steps: (1) Mixing pretreatment: Weigh 500g of spherical silica powder and place it in a high-speed mixer. Add 100g of ethanol (the same type and amount of solvent as in Example 1), heat to 70°C, and stir at 800 rpm for 30 minutes to ensure that the powder and ethanol are fully mixed and dispersed without obvious agglomeration.

[0066] (2) Silane addition reaction: 5 g of N-phenyl-3-aminopropyltrimethoxysilane (without pre-hydrolysis and without added deionized water) was directly poured into the above mixture and stirred at 800 rpm for 1 hour to make the silane, powder and ethanol evenly mixed.

[0067] (3) Post-processing: Same as in Example 1, raise the temperature of the high-speed mixer to 100°C, continue stirring and reacting at a speed of 1000 rpm for 2 hours, discharge the material, and obtain modified inorganic powder, which is denoted as modified powder D3.

[0068] Comparative Example 4 This comparative example provides a method for modifying inorganic powders, the method comprising the following steps: (1) Powder pretreatment: Same as in Example 1, weigh 500g of spherical silica powder and place it in a high-speed mixer, heat it to 70℃, and stir it at 800 rpm for 30 minutes.

[0069] (2) Preparation of hydrolysate: Same as in Example 1, 5 g of N-phenyl-3-aminopropyltrimethoxysilane was mixed with 100 g of ethanol, and deionized water (2.0 times the theoretical amount of water to be hydrolyzed) was slowly added dropwise at 25°C with stirring, and stirring was continued for 1 hour to obtain silane hydrolysate.

[0070] (3) Pouring and coating reaction: The prepared silane hydrolysate is slowly poured into the preheated powder being stirred at high speed. The pouring process lasts for 5 minutes. After pouring, the mixture is stirred at 800 rpm for 15 minutes to allow the hydrolysate and powder to be initially mixed (the total mixing time is the same as the spraying time in Example 1).

[0071] (4) Post-processing: Same as in Example 1, raise the temperature of the high-speed mixer to 100°C, continue stirring and reacting at a speed of 1000 rpm for 2 hours, discharge the material, and obtain modified inorganic powder, which is denoted as modified powder D4.

[0072] Application Example 1 In this application example, a resin composition is provided, the specific components and amounts (by weight percentage) of which are shown in Table 1.

[0073] This application example also provides a carrier insulating film, which is prepared by the following method: The above resin composition was cured at 180°C for 0.5 h to obtain the carrier plate insulating film.

[0074] The performance of the resin composition and the carrier insulating film was tested. Among them, the tests (2) coefficient of thermal expansion (CTE) ~ (6) water absorption rate (24h) were all performed on the carrier insulating film. The test methods are as follows: (1) Viscosity of resin composition (25℃): The viscosity was tested in accordance with GB / T 10247-2008 "Viscosity Measurement Method". The test speed was 20r / min. Each sample was tested 3 times and the average value was taken as the final viscosity value.

[0075] (2) Coefficient of thermal expansion (CTE): The test was conducted according to IPC-TM-650 2.4.24.1 standard. The test temperature range was 25~120℃ (lower than the glass transition temperature Tg), the heating rate was 5℃ / min, the sample size was 5mm×20mm×0.1mm, and the test was conducted 3 times and the average value was taken.

[0076] (3) Dielectric constant and dielectric loss: The test was conducted according to the IPC-TM-650 2.5.5.12 standard. The test frequency was 10GHz, the test temperature was 25℃, the sample size was 50mm×50mm×0.1mm, and 3 points were tested for each sample. The average value was taken.

[0077] (4) Glass transition temperature (Tg): The test was conducted in accordance with GB / T 19466.2-2004 Differential scanning calorimetry (DSC) for plastics - Part 2: Determination of glass transition temperature. The heating rate was 10℃ / min, and the test temperature range was 25~300℃. The midpoint of the baseline shift in the DSC curve was taken as the Tg value. The test was conducted 3 times and the average value was taken.

[0078] (5) Copper bonding strength: The test was conducted according to IPC-TM-650 2.4.9 standard. The insulating film of the carrier board was hot-pressed with 1oz of electrolytic copper foil (hot pressing conditions: 180℃, 0.3MPa, 30min) to make a copper-film-copper sample. The 90° peeling method was used, the peeling speed was 50mm / min, and 5 samples were tested. The average value after removing the maximum and minimum values ​​was taken as the copper bonding strength.

[0079] (6) Water absorption rate (24h): The test was conducted in accordance with GB / T 1034-2008 "Determination of water absorption of plastics". The insulating film of the carrier board was cut into samples of 20mm×20mm×0.1mm. The samples were dried in an oven at 105℃ for 2h. After cooling to room temperature, the mass (m0) was weighed. Then the samples were immersed in deionized water at 25℃ for 24h. After soaking, the samples were taken out and the surface moisture was absorbed with filter paper. The mass (m1) was weighed. The formula for calculating the water absorption rate is: water absorption rate (%) = (m1-m0) / m0×100%. Three samples were tested and the average value was taken.

[0080] Application Example 2-4, Comparison with Application Example 1-4 The only difference from Application Example 1 is that the specific components and / or amounts of the resin composition are different, as shown in Tables 1 and 2.

[0081] The performance test results are shown in Tables 1 and 2.

[0082] Table 1 Table 2 As can be seen from Table 1, the carrier insulating films obtained by the modified inorganic powder provided by the present invention all have high heat resistance (CTE: 10.8~12ppm / ℃), good dielectric properties (dielectric loss: 0.0035~0.0042), high Tg (155~215℃), high adhesion (copper bonding strength: 6.8~7.4N / cm) and low water absorption (0.25%~0.32%).

[0083] Compared with Application Example 1, the heat resistance, dielectric properties, Tg, adhesive properties, and water absorption resistance of the carrier insulating film provided in Comparative Application Examples 1-4 all decreased.

[0084] The applicant declares that this invention illustrates the method for modifying inorganic powders, the modified inorganic powders, and the carrier insulating film through the above embodiments. However, this invention is not limited to the above embodiments, meaning that this invention does not necessarily rely on the above embodiments for implementation. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials used, additions of auxiliary components, and selection of specific methods all fall within the protection and disclosure scope of this invention.

Claims

1. A method for modifying inorganic powders, characterized in that, The modification method includes the following steps: (1) Drying the inorganic powder; (2) Mix the silane coupling agent with an alcohol solvent, add deionized water while stirring, and continue stirring to obtain a silane hydrolysate; (3) Spray the silane hydrolysate obtained in step (2) into the inorganic powder obtained in step (1) under stirring, heat up, stir and react to obtain modified inorganic powder.

2. The modification method according to claim 1, characterized in that, The inorganic powder in step (1) includes silica powder; Preferably, the silica powder is spherical silica micropowder; Preferably, the median particle size D50 of the silica powder is 0.1~5μm.

3. The modification method according to claim 1 or 2, characterized in that, The drying process described in step (1) is carried out in a high-speed mixer; Preferably, the high-speed mixer rotates at a speed of 500-1000 rpm; Preferably, the drying temperature in step (1) is 60~80℃ and the drying time is 20~40 minutes; Preferably, the drying treatment of the inorganic powder in step (1) specifically includes: The inorganic powder is placed in a high-speed mixer at a speed of 500-1000 rpm and stirred at 60-80℃ for 20-40 minutes.

4. The modification method according to any one of claims 1-3, characterized in that, The silane coupling agent in step (2) includes any one or a combination of at least two of phenylsilane, phenylaminosilane, vinylsilane or aminosilane; Preferably, the phenylsilane comprises N-phenyl-3-aminopropyltrimethoxysilane and / or phenyltrimethoxysilane; Preferably, the phenylaminosilane includes phenylaminopropyltrimethoxysilane.

5. The modification method according to any one of claims 1-4, characterized in that, The alcohol solvent in step (2) includes ethanol and / or isopropanol; Preferably, the mass ratio of the silane coupling agent to the alcohol solvent in step (2) is 1:(5~20); Preferably, the amount of deionized water added in step (2) is 1.5 to 2.5 times the amount of water theoretically required for the complete hydrolysis of the silane coupling agent; Preferably, the amount of silane coupling agent used in step (2) is 0.5% to 5% of the mass of the inorganic powder in step (1).

6. The modification method according to any one of claims 1-5, characterized in that, The continuous stirring described in step (2) is carried out at 20~40℃; Preferably, the continuous stirring time in step (2) is 0.5 to 2 hours.

7. The modification method according to any one of claims 1-6, characterized in that, The spraying in step (3) is achieved by a spraying device; Preferably, the temperature rise in step (3) is to 80~110℃; Preferably, the stirring speed in step (3) is 500~1000 rpm; Preferably, the stirring reaction time in step (3) is 1 to 3 hours.

8. A modification method as described in any one of claims 1-7, characterized in that, The modification method includes the following steps: (1) Place the inorganic powder in a high-speed mixer with a speed of 500~1000 rpm and stir at 60~80℃ for 20~40 minutes; (2) Mix the silane coupling agent with an alcohol solvent, add deionized water while stirring, and continue stirring at 20~40℃ for 0.5~2 hours to obtain a silane hydrolysate; (3) The silane hydrolysate obtained in step (2) is sprayed into the inorganic powder obtained in step (1) under stirring through a spraying device. After spraying, the temperature is raised to 80~110℃, and the temperature is maintained and stirred at a speed of 500~1000 rpm for 1~3 hours to obtain the modified inorganic powder.

9. A modified inorganic powder, characterized in that, The modified inorganic powder is prepared by the modification method described in any one of claims 1-8.

10. A carrier insulating film, characterized in that, The raw materials for preparing the carrier insulating film include a resin matrix and filler powder, wherein the filler powder includes the modified inorganic powder as described in claim 9; Preferably, the content of the filler powder is 70% to 75%, based on the total weight of the raw materials used to prepare the carrier insulating film as 100%.

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