Chemical copper plating nano modifier for SLP type support plate aMSAP process and preparation method thereof

Abstract

The invention discloses a chemical copper plating nano modifier for an SLP type carrier plate aMSAP process and a preparation method of the chemical copper plating nano modifier, and belongs to the technical field of new materials. Aiming at the problems of poor uniformity, weak adhesive force, insufficient oxidation resistance and poor durability of a copper layer in the existing chemical copper plating technology, the preparation method comprises the following steps: designing a nano modifier comprising a template agent, a silane precursor, a surface modifier and a WO3 (at) ITO core-shell structure, and adopting a template agent assisted sol-gel method and a hot coating and interface self-assembly process to prepare the nano-copper plating film. According to the modifier, the performance of a copper layer is remarkably improved, the thickness standard deviation is smaller than or equal to 0.14 mu m, the adhesion rate is larger than or equal to 98.0%, the copper oxide content is smaller than or equal to 2.3 mol%, and performance attenuation is extremely small after a durability test. The preparation process is simple, the additive amount is low, the method is highly compatible with an aMSAP process, the cost is low, the method is environmentally friendly, the requirements for high-density interconnection and high-reliability manufacturing of SLP type carrier plates are met, and the method has remarkable industrial application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of new materials, and specifically relates to a chemical copper plating nano modifier for aMSAP process of SLP type carrier board and a preparation method thereof. Background Art

[0002] With the rapid development of the electronic information industry, as a core component of high-performance electronic products such as smart phones, tablet computers, 5G communication devices and wearable devices, high density interconnect boards (HDI) have put forward higher requirements for their manufacturing processes. As an advanced HDI technology, substrate-like packaging (SLP) significantly improves the integration and signal transmission efficiency of circuit boards through refined line width / line pitch (usually ≤ 30μm / 30μm) and high density via hole design. As one of the key technologies for SLP manufacturing, the aMSAP (Advanced Modified Semi-Additive Process) process forms a fine conductive copper layer on the substrate surface through electroless copper plating and electroplating processes to meet the requirements of high density wiring and complex three-dimensional structures. However, as the initial step of the aMSAP process, the performance of electroless copper plating directly determines the quality of subsequent electroplating and the reliability of the final product. Therefore, the development of high-performance electroless copper plating technology is the key point and difficulty in the field of SLP type carrier board manufacturing.

[0003] Electroless copper plating technology deposits a uniform copper film on the surface of non-conductive substrates (such as resins, ceramics, or glass fibers) to provide a conductive seed layer for subsequent electroplating. The core lies in the performance of catalysts or modifiers. The catalyst should have high dispersibility, strong interfacial binding force, and excellent catalytic activity to ensure the uniformity, adhesion, and long-term stability of the copper layer. Traditional electroless copper plating processes usually use noble metal catalysts (such as palladium-based catalysts) or simple metal oxides (such as CuO, TiO2), combined with a single carrier material (such as silica or polymer microspheres) to promote the reduction and deposition of copper ions. However, the existing technologies have the following significant problems in practical applications: Insufficient copper layer uniformity: The dispersibility and interfacial reaction control ability of existing electroless copper plating catalysts are limited, resulting in uneven copper layer thickness distribution. Literature and experimental data show that the standard deviation (SD) of the copper layer thickness prepared by traditional processes is usually in the range of 0.25 - 0.45 μm. Especially on the surface of high aspect ratio vias or complex substrates, local over-thickness or under-thickness phenomena are likely to occur. This not only increases the difficulty of subsequent electroplating but also may lead to inconsistent signal transmission impedance, affecting the electrical performance of SLP-type carrier boards. Weak copper layer adhesion: In the existing technologies, the interfacial chemical bonding between the catalyst and the substrate or the copper layer is insufficient, and the adhesion rate in the cross-cut test is usually lower than 91.5%. In complex environments such as high-frequency vibration, thermal cycling, or mechanical stress, the copper layer is prone to peeling or microcracks, severely limiting the application of SLP-type carrier boards in high-reliability scenarios (such as automotive electronics, aerospace). Insufficient antioxidant performance: The electroless copper plating layer is prone to oxidation in high-temperature and high-humidity environments (such as 85°C, 85% humidity), and the copper oxide content can be as high as 7.8 - 15.8 mol%, resulting in a decrease in electrical conductivity and a shortening of device life. This is particularly fatal in high-performance electronic products because the oxide layer will significantly increase the contact resistance and reduce the long-term stability of the circuit board. Insufficient durability: The performance of existing electroless copper plating layers degrades significantly under extreme conditions (such as high-temperature and high-humidity cycling, mechanical damage, or acidic environment). Experiments show that after the durability test of the copper layer prepared by traditional processes, the standard deviation of the thickness increases to more than 0.30 μm, the adhesion rate drops below 87.5%, and the copper oxide content increases significantly (≥10.8 mol%). This cannot meet the high-reliability requirements of SLP-type carrier boards in harsh environments. Process complexity and cost issues: The preparation process of traditional electroless copper plating catalysts is relatively complex, and a high concentration of catalyst (>1.0 g / L) is required to achieve limited performance improvement, increasing the production cost. In addition, some catalysts (such as palladium-based catalysts) rely on noble metals, which are expensive, and the organic solvents or chemical additives used in the preparation process are not environmentally friendly, limiting the application prospects of green manufacturing. Insufficient component and process synergy: Existing catalysts or modifiers usually adopt single-functional components (such as simple metal oxides or inorganic carriers), lacking the synergistic optimization of multi-components, resulting in low catalytic efficiency and poor dispersibility.Traditional preparation processes (such as simple mixing or physical deposition) cannot achieve precise control of the catalyst structure and are difficult to achieve uniform and stable copper layer deposition on the complex substrate surfaces of SLP-type carrier plates.

[0004] To address the above problems, in recent years, researchers have attempted to improve electroless copper plating performance by modifying catalyst components and preparation processes. For example, some studies have introduced nanocomposites (such as SiO2@metal oxides) as catalyst carriers to improve dispersibility and catalytic activity; other studies have enhanced the adhesion between the copper layer and the substrate through surface modification techniques. However, these methods still have limitations: the pore structures of single carrier materials are irregular, making it difficult to achieve uniform deposition of copper ions; the selection and functionalization degree of surface modifiers are insufficient, making it difficult to balance adhesion and antioxidant properties; in addition, the lack of precise control of the microstructure of the catalyst results in limited performance improvement, making it difficult to meet the requirements of high uniformity, high adhesion, and long lifespan for the aMSAP process of SLP-type carrier plates. Summary of the Invention

[0005] 1. Problems to be Solved

[0006] Aiming at the deficiencies of the prior art in aspects such as the uniformity, adhesion, antioxidant performance, durability, and process economy of electroless copper plating in the aMSAP process of SLP-type carrier plates, the present invention designs a novel electroless copper plating nano-modifier and its preparation method, optimizes key components (such as templating agents, silane precursors, WO3@ITO core-shell structures) and process steps (such as thermal coating, interfacial self-assembly), aiming to significantly improve the performance of the copper layer and meet the requirements of high-reliability and low-cost manufacturing of high-density interconnect boards.

[0007] 2. Technical Solutions

[0008] To solve the above problems, the present invention adopts the following technical solutions.

[0009] A preparation method of electroless copper plating nano modifier for aMSAP process of SLP type carrier board, comprising the following steps: (1) Functionalization treatment of mesoporous silicon carrier: Mix the template agent, silane precursor and surface modifier according to the mass ratio of 1:(0.5-2):(0.1-0.5), carry out hydrolysis and condensation reaction under alkaline conditions, and obtain mesoporous silica nanoparticles after the reaction; (2) Construction of metal oxide core-shell structure: Prepare an aqueous solution by mixing tungstate precursor, ammonium sulfate and water according to the mass ratio of (3-5):1:(15-20), adjust the pH to 1.5-2.5 for hydrothermal reaction to generate WO3 nanorods, and then carry out thermal coating with indium tin precursor according to the mass ratio of (10-20):1 to form WO3@ITO core-shell structure; (3) Assembly of composite modifier: Mix the mesoporous silica nanoparticles obtained in step (1) with the WO3@ITO core-shell structure obtained in step (2) according to the mass ratio of (1-3):1, add a nitrogen-containing organic dispersant and a boric acid-based buffer solution, and carry out interfacial self-assembly under the action of an ultrasonic field to obtain an electroless copper plating nano modifier.

[0010] Preparation method of electroless copper plating nano modifier for SLP-class carrier board aMSAP process. The preparation method of the template agent described in step (1) is as follows: Cetyltrimethylammonium bromide (CAS No. 57-09-0) and poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer (CAS No. 9003-11-6, Pluronic type P-123 (PEO-PPO-PEO) of BASF SE) are mixed at a mass ratio of 1:(0.2 - 0.8), and an aqueous solution containing 0.5 - 2 wt% sodium tartrate (CAS No. 868-18-8) with a mass 10 - 20 times that of cetyltrimethylammonium bromide is added. Ultrasonic dispersion is carried out at a power of 120 W for 40 - 60 min at 50 - 70 °C to form amphiphilic composite micelles. Then, tapioca starch (CAS No. 9005-25-8, 100 mesh, sourced from South China No. 9 SC9 tapioca, with a linear starch mass percentage content of 22.56%, swelling degree of 10.35%, solubility of 28.00%, relative crystallinity of 26.49%, infrared ratio of short-range ordered structure of 0.756, and average particle size of 12.40 μm) is added and mixed. The mass ratio between tapioca starch and cetyltrimethylammonium bromide is (0.2 - 0.6):1. Then, stepwise temperature treatment is adopted (using a reaction kettle with a temperature control unit, such as CORIO CD-200F produced by Julabo GmbH, USA): The first stage: maintain at 65 - 75 °C for 30 - 60 min, the second stage: rapidly cool to 0 - 5 °C and maintain for 10 - 15 min, the third stage: heat up to 40 - 50 °C at a rate of 2 - 5 °C / min. After stepwise temperature treatment, the product is soaked in an ethanol solution containing 0.1 - 0.5 mol / L citric acid, where the mass of the ethanol solution is 20 - 30 times that of the product. Subsequently, ultraviolet curing treatment is carried out under nitrogen protection. Ultraviolet light source: UV-A, wavelength 365 nm, light intensity: 20 mW / cm 2 , irradiation time: 15 min, nitrogen protection: flow rate 1 L / min, purity 99.999%, curing temperature: 25 °C, to obtain a template agent with light-responsive characteristics.

[0011] Preparation method of electroless copper plating nano modifier for SLP type carrier board aMSAP process. The preparation method of silane precursor in step (1) is as follows: Tetraethoxysilane (CAS No. 78-10-4) and triethoxy-3-(2-imidazolin-1-yl)propylsilane (CAS No. 58068-97-6) are mixed in a molar ratio of (5-8):1, and an ethanol solution containing 1-2 wt% 1,8-diazabicycloundec-7-ene (CAS No. 6674-22-2) with a mass 5-10 times that of tetraethoxysilane is added. Hydrolysis reaction is carried out under anaerobic conditions (nitrogen protection), and the parameters of the hydrolysis reaction are as follows: temperature 45-50 °C, 2-4 h. Then, 3-mercaptopropyltrimethoxysilane (CAS No. 4420-74-0) is introduced into the product of the hydrolysis reaction. The molar ratio between 3-mercaptopropyltrimethoxysilane and tetraethoxysilane is (0.3-0.6):1. Microwave-assisted synthesis method is adopted: power density: 50-100 W / L, pressure control: 0.5-2 MPa, reaction time: 10-30 min. Finally, it is soaked in an acetone solution containing 0.1-0.5 wt% benzotriazole (CAS No. 95-14-7), and the mass dosage of the acetone solution is 20-30 times that of tetraethoxysilane. Subsequently, cross-linking is initiated under ultraviolet light. Ultraviolet light source: UV-A, wavelength 312 nm, light intensity: 25 mW / cm 2 , irradiation time: 30 min, nitrogen protection: flow rate 1 L / min, purity 99.999%, cross-linking temperature: 45 °C.

[0012] Preferably, the surface modifier in step (1) is a mixed solution of 3-aminopropyltriethoxysilane (CAS No. 919-30-2) and vinyltrimethoxysilane (CAS No. 2768-02-7) in a molar ratio of (0.5-2):1; the parameters of the hydrolysis and condensation reaction under alkaline conditions in step (1) are as follows: pH value 10-12, temperature 60-80 °C, reaction time 2-4 h, stirring speed 500-1000 rpm.

[0013] Preferably, the preparation method of the tungstate precursor in step (2) is as follows: Ammonium metatungstate (CAS No. 12028-48-7) and silicotungstic acid (CAS No. 12027-38-2) are mixed at a mass ratio of (3-5):1, and an ethylene glycol solution containing 0.1-0.5 mol / L ascorbic acid (CAS No. 50-81-7) and 15-20 times the mass of ammonium metatungstate is added. The reaction is carried out under microwave assistance, where the power of the reaction is 200-400 W, the temperature of the reaction is 80-120 °C, and the reaction time is 10-30 min. Then, ammonium cerium nitrate (CAS No. 16774-21-3) with a mass 0.2-0.6 times that of ammonium metatungstate is added and treated by ultrasonic cavitation effect (Branson Sonifier series ultrasonic generators, such as SFX250), where the frequency of the ultrasonic cavitation effect is 20-40 kHz and the power density is 50-100 W / L. Subsequently, a staged hydrothermal crystallization process is adopted: The first stage: maintain at 100-120 °C for 4-6 h, the second stage: rapidly heat up to 180-200 °C and hold for 0.5-1 h, the third stage: gradually cool down to 80-100 °C to obtain the tungstate precursor; The parameters of the hydrothermal reaction in step (2) are as follows: 120-140 °C, 6-10 h.

[0014] Preferably, the preparation method of the indium tin precursor in step (2) is as follows: Indium acetylacetonate (CAS No. 14405-45-9) and dibutyltin dilaurate (CAS No. 77-58-7) are mixed at a molar ratio of (3-5):2, and an ethylene glycol solution containing 10-20 wt% dodecyl mercaptan (CAS No. 112-55-0) and 5-8 times the mass of indium acetylacetonate is added. Subsequently, microwave treatment is carried out, where the parameters of the microwave treatment are as follows: power 300-500 W, temperature 120-150 °C, pressure 0.5-1.5 MPa, to obtain the indium tin precursor.

[0015] Preferably, the parameters of the thermal coating in step (2) are as follows: An asymmetric three-stage temperature control program is adopted (for example, a common PID temperature controller, the AI-708P type device produced by Xiamen Yudian Automation Technology Co., Ltd.). Nucleation stage: maintain at 120-150 °C for 0.5-1 h, crystallization stage: hold at 180-220 °C for 2-4 h, pressure 0.5-1.5 MPa, annealing stage: cool down to 80-100 °C at a rate of 5 °C / min.

[0016] Preferably, the nitrogen-containing organic dispersant in step (3) is oil-based aminoethyl imidazoline (CAS No. 25749-86-4), and the final mass percentage of the nitrogen-containing organic dispersant is 5-10%; the boric acid-based buffer solution in step (3) is a 0.05-0.2 M sodium tetraborate solution, and the mass ratio between it and the nitrogen-containing organic dispersant is 10:(2-3); the parameters of the ultrasonic field in step (3) are as follows: frequency 10-20 MHz, 30-45 min.

[0017] A chemical copper plating nano modifier for SLP-class carrier board aMSAP process, and the chemical copper plating nano modifier for SLP-class carrier board aMSAP process is obtained by the preparation method described above.

[0018] 3. Beneficial effects

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: significantly improving the uniformity of the copper layer: By optimizing the ratio of the templating agents (CTAB, P-123, and cassava starch) and the silane precursors (TEOS, imidazoline silane, 3-mercaptopropyltrimethoxysilane), the present invention prepares a silica support with a regular mesoporous structure. Combining the WO3@ITO core-shell structure and the interfacial self-assembly process, a highly uniform copper layer is formed by the electroless copper nano-modifier (CMN) in the aMSAP process of SLP-type substrates. The test results of Experimental Examples 2-6 show that the standard deviation (SD) of the copper layer thickness in Examples 1-20 is ≤0.14 μm, far lower than 0.45 μm in Comparative Example 1 and 0.25-0.38 μm in Comparative Examples 2-15. The uniformity is improved by about 68.9%-72.2%, effectively reducing the thickness deviation in via plating and improving the reliability of high-density interconnect boards. Enhancing the adhesion of the copper layer: Through the synergistic effect of the surface modifiers (3-aminopropyltriethoxysilane and vinyltrimethoxysilane) and the functionalized silane precursors, the present invention enhances the interfacial chemical bonding between the modifier and the copper layer. The cross-cut tape test results of Experimental Examples 2-6 show that the adhesion rate of the copper layer in Examples 1-20 is ≥98.0%, which is about 13.6%-15.3% higher than that in Comparative Example 1 (85.0%) and Comparative Examples 2-15 (86.5%-91.5%). This significantly reduces the risk of copper layer peeling and meets the stability requirements of SLP-type substrates in complex stress environments. Excellent antioxidant performance: By using the WO3@ITO core-shell structure and the thermal coating process, the present invention endows the modifier with excellent antioxidant protection ability. The XPS test results of Experimental Examples 2-6 show that the copper oxide content in the copper layer of Examples 1-20 after aging at 85°C and 85% humidity for 48 h is ≤2.3 mol%, far lower than 15.8 mol% in Comparative Example 1 and 7.8-12.0 mol% in Comparative Examples 2-15. The antioxidant performance is improved by about 85.4%-87.7%. This effectively extends the service life of the copper layer and is suitable for the manufacture of high-reliability electronic devices. Excellent durability: By optimizing the structural integrity of the modifier through the thermal coating and interfacial self-assembly processes, the present invention enables the copper layer to maintain excellent performance under harsh conditions. The durability test results of Experimental Example 7 show that Examples 1, 5, and 10 are subjected to high-temperature and high-humidity cycling (85°C, 85% humidity), mechanical damage (10 per dm 2After perforation and in an acidic environment (pH 4.0, 48 h), the standard deviation of thickness ≤ 0.16 μm, the adhesion rate ≥ 97.3%, the copper oxide content ≤ 2.6 mol%, while the performance of Comparative Examples 12 - 15 decreased significantly (SD ≥ 0.30 μm, adhesion rate ≤ 87.5%, copper oxide content ≥ 10.8 mol%). The durability was improved by about 46.7% - 50.0%, ensuring the stability of SLP - type carrier plates during long - term use. Process compatibility and environmental adaptability: The preparation process of the modifier in the present invention (template - assisted sol - gel method, thermal coating, interfacial self - assembly) is simple to operate, compatible with the existing aMSAP process, without the need for additional equipment or complex steps. The addition amount of the modifier is only 0.5 g / L, which can significantly improve the performance, with low cost and suitable for large - scale production. At the same time, natural components such as cassava starch in the modifier improve environmental friendliness and reduce the generation of chemical waste. Synergistic effect of key components: Through the comparison of Experimental Examples 2 - 6, it is proved that the synergistic effect of the template agent, silane precursor, surface modifier, tungstate, and indium tin precursor is the key to performance improvement. In Comparative Examples 1 - 15, the performance decreased significantly by missing any key component or process step (such as template agent, thermal coating, interfacial self - assembly), verifying the necessity of each component and the scientific nature of the overall process. In particular, the unique design of the WO3@ITO core - shell structure combined with mesoporous silica significantly enhances the dispersibility, conductivity, and interfacial activity of the modifier. Description of the Drawings

[0020] Figure 1 is the flow chart of the preparation method of the electroless copper - plating nano - modifier for the aMSAP process of SLP - type carrier plates in the present invention.

[0021] Figure 2 is the transmission electron microscope image of the mesoporous silica nanoparticles prepared in Example 8.

[0022] Figure 3 is the transmission electron microscope image of the WO3@ITO core - shell structure prepared in Example 8.

[0023] Figure 4 is the transmission electron microscope image of the electroless copper - plating nano - modifier prepared in Example 8. Detailed Description of the Invention

[0024] The present invention will be described in detail below through specific examples. However, the uses and purposes of these exemplary embodiments are only used to illustrate the present invention, and do not constitute any form of limitation to the actual protection scope of the present invention, nor limit the protection scope of the present invention thereto. For parameter ranges not mentioned, intermediate values are selected. At the same time, for mass percentages or weight percentages not clearly stated or mentioned, it generally refers to the final concentration after addition. In addition, for mass fractions or weight parts involved, grams can be used as the mass unit or weight unit during application.

[0025] The substance information involved is as follows: Cetyltrimethylammonium bromide (CTAB): CAS No. 57-09-0; Poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer (P-123): CAS No. 9003-11-6; Sodium tartrate: CAS No. 868-18-8; Cassava starch: CAS No. 9005-25-8 (100 mesh, South China No. 9 SC9 cassava, amylose content 22.56%, swelling degree 10.35%, solubility 28.00%, relative crystallinity 26.49%, infrared ratio of short-range ordered structure 0.756, average particle size 12.40 μm); Citric acid: CAS No. 77-92-9; Tetraethoxysilane (TEOS): CAS No. 78-10-4; Triethoxy-3-(2-imidazolin-1-yl)propylsilane: CAS No. 58068-97-6; 1,8-Diazabicycloundec-7-ene (DBU): CAS No. 6674-22-2; 3-Mercaptopropyltrimethoxysilane: CAS No. 4420-74-0; Benzotriazole: CAS No. 95-14-7; 3-Aminopropyltriethoxysilane: CAS No. 919-30-2; Vinyltrimethoxysilane: CAS No. 2768-02-7; Ammonium metatungstate: CAS No. 12028-48-7; Silicotungstic acid: CAS No. 12027-38-2; Ascorbic acid: CAS No. 50-81-7; Ammonium cerium(IV) nitrate: CAS No. 16774-21-3; Indium acetylacetonate: CAS No. 14405-45-9; Dibutyltin dilaurate: CAS No. 77-58-7; Dodecyl mercaptan: CAS No. 112-55-0; Oil-based amine ethyl imidazoline: CAS No. 25749-86-4; Sodium tetraborate: CAS No. 1330-43-4.

[0026] Refer to Figure 1 According to the preparation flow chart shown, the present invention provides a preparation method of an electroless copper plating nano modifier for SLP class carrier plates aMSAP process, and the technical solution is as follows.

[0027] Example 1

[0028] Template agent preparation: Mix 1 part of cetyltrimethylammonium bromide (CTAB) with 0.2 part of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer (P-123), add 10 parts of an aqueous solution containing 0.5 wt% sodium tartrate, and ultrasonically disperse at 50 °C with a power of 120 W for 40 min to form amphiphilic composite micelles. Add 0.2 part of tapioca starch (mass ratio to CTAB is 0.2:1), and perform stepwise temperature treatment (using a reaction kettle with a temperature control unit, Julabo CORIO CD-200F): maintain at 65 °C for 30 min in the first stage, rapidly cool to 0 °C and maintain for 10 min in the second stage, and heat to 40 °C at a rate of 2 °C / min in the third stage. After treatment, soak with an ethanol solution containing 0.1 mol / L citric acid (20 times the mass of the product), and perform ultraviolet curing (UV-A, 365 nm, 20 mW / cm 2 , 15 min, curing temperature 25 °C) under nitrogen protection (flow rate 1 L / min, purity 99.999%) to obtain a light-responsive template agent.

[0029] Silane precursor preparation: Mix 5 parts of tetraethoxysilane (TEOS) with 1 part of triethoxy-3-(2-imidazolin-1-yl)propylsilane (molar ratio 5:1), add 25 parts of an ethanol solution containing 1 wt% DBU, and hydrolyze at 45 °C for 2 h under nitrogen protection (flow rate 1 L / min, purity 99.999%). Add 0.3 part of 3-mercaptopropyltrimethoxysilane (molar ratio to TEOS is 0.3:1) to the product, and perform microwave-assisted synthesis (50 W / L, 0.5 MPa, 10 min). Soak with an acetone solution containing 0.1 wt% benzotriazole (20 times the mass of TEOS), and initiate crosslinking under ultraviolet light (UV-A, 312 nm, 25 mW / cm 2 , 30 min, nitrogen protection, flow rate 1 L / min, purity 99.999%, crosslinking temperature 45 °C) to obtain a silane precursor.

[0030] Functionalization treatment of mesoporous silica support: Mix 1 part of the template agent, 0.5 part of the silane precursor, and 0.1 part of the surface modifier (molar ratio of 3-aminopropyltriethoxysilane to vinyltrimethoxysilane is 0.5:1), and perform hydrolysis and condensation at pH 10, 60 °C, and a stirring speed of 500 rpm for 2 h to obtain mesoporous silica nanoparticles.

[0031] Preparation of tungstate precursor: Mix 3 parts of ammonium metatungstate with 1 part of silicotungstic acid, add 45 parts of ethylene glycol solution containing 0.1 mol / L ascorbic acid, and react under microwave assistance (200 W, 80 °C, 10 min). Add 0.6 part of ammonium cerium nitrate, treat by ultrasonic cavitation (20 kHz, 50 W / L), and adopt staged hydrothermal crystallization: maintain at 100 °C for 4 h in the first stage, rapidly heat up to 180 °C and keep for 0.5 h in the second stage, and gradually cool down to 80 °C in the third stage to obtain the tungstate precursor.

[0032] Preparation of indium tin precursor: Mix 3 parts of indium acetylacetonate with 2 parts of dibutyltin dilaurate (molar ratio 3:2), add 15 parts of ethylene glycol solution containing 10 wt% dodecyl mercaptan, and perform microwave treatment (300 W, 120 °C, 0.5 MPa) to obtain the indium tin precursor.

[0033] Construction of metal oxide core-shell structure: Prepare a solution by mixing 3 parts of tungstate precursor, 1 part of ammonium sulfate, and 15 parts of water, adjust the pH to 1.5, and perform hydrothermal reaction at 120 °C for 6 h to generate WO3 nanorods. Perform thermal coating on the WO3 nanorods and indium tin precursor (mass ratio 10:1) (nucleation: 120 °C, 0.5 h; crystallization: 180 °C, 2 h, 0.5 MPa; annealing: cool down to 80 °C at 5 °C / min) to form a WO3@ITO core-shell structure.

[0034] Assembly of composite modifier: Mix 1 part of mesoporous silica nanoparticles with 1 part of WO3@ITO core-shell structure, add a dispersant containing 5 wt% oil-based amine ethyl imidazoline and 0.05 M sodium tetraborate buffer solution (mass ratio 10:2), and perform interfacial self-assembly for 30 min under the action of a 10 MHz ultrasonic field to obtain an electroless copper plating nano-modifier (hereinafter referred to as CMN).

[0035] Example 2 - 20

[0036] Examples 2 - 20 refer to the process flow and experimental methods of Example 1, but some parameters are adjusted. The specific process parameters are summarized in Table 1.

[0037] Table 1 Summary of process parameters for Examples 1 - 20

[0038]

[0039]

[0040]

[0041] Comparative Example 1

[0042] Different from Example 1, the electroless copper plating step in the aMSAP process of the SLP type carrier board is directly carried out without preparing the electroless copper plating nano modifier, and the obtained copper layer is called Cu-0.

[0043] Comparative Example 2

[0044] Different from Example 1, the template agent is not prepared, and CTAB, P-123 and tapioca starch are directly mixed in a ratio of 1:0.2:0.2 and then added to an aqueous solution containing 0.5 wt% sodium tartrate, and after simple stirring, it is used for the functionalization treatment of the mesoporous silicon carrier, and the obtained modifier is called CMN-2.

[0045] Comparative Example 3

[0046] Different from Example 1, tapioca starch is not added, and the template agent is prepared only by mixing CTAB and P-123 in a ratio of 1:0.2, and the obtained modifier is called CMN-3.

[0047] Comparative Example 4

[0048] Different from Example 5, the silane precursor is not prepared, and TEOS, triethoxy-3-(2-imidazolin-1-yl)propylsilane and 3-mercaptopropyltrimethoxysilane are directly mixed in a molar ratio of 5:1:0.3 and then used for the functionalization treatment of the mesoporous silicon carrier, and the obtained modifier is called CMN-4.

[0049] Comparative Example 5

[0050] Different from Example 5, 3-mercaptopropyltrimethoxysilane is not added, and the silane precursor is prepared only by mixing TEOS and triethoxy-3-(2-imidazolin-1-yl)propylsilane in a molar ratio of 5:1, and the obtained modifier is called CMN-5.

[0051] Comparative Example 6

[0052] Different from Example 10, the surface modifier treatment is not carried out, and the mesoporous silicon carrier is functionalized only by mixing the template agent and the silane precursor in a ratio of 1:0.5, and the obtained modifier is called CMN-6.

[0053] Comparative Example 7

[0054] Different from Example 10, 3-aminopropyltriethoxysilane is not added, and only vinyltrimethoxysilane is used as the surface modifier, and the obtained modifier is called CMN-7.

[0055] Comparative Example 8

[0056] Different from Example 15, the tungstate precursor is not prepared, and ammonium metatungstate, silicotungstic acid and cerium ammonium nitrate are directly mixed in a ratio of 3:1:0.6 and then used for the construction of the metal oxide core-shell structure, and the obtained modifier is called CMN-8.

[0057] Comparative Example 9

[0058] Different from Example 15, ammonium cerium nitrate was not added, and only ammonium metatungstate and silicotungstic acid were used to prepare the tungstate precursor in a ratio of 3:1. The resulting modifier was designated as CMN-9.

[0059] Comparative Example 10

[0060] Different from Example 20, the preparation of indium tin precursor was not carried out. Indium acetylacetonate and dibutyltin dilaurate were directly mixed in a molar ratio of 3:2 and used for thermal coating. The resulting modifier was designated as CMN-10.

[0061] Comparative Example 11

[0062] Different from Example 20, dibutyltin dilaurate was not added, and only indium acetylacetonate was used to prepare the indium tin precursor. The resulting modifier was designated as CMN-11.

[0063] Comparative Example 12

[0064] Different from Example 1, the thermal coating treatment was not carried out. WO3 nanorods and indium tin precursor were simply blended in a ratio of 10:1 and used for the assembly of the composite modifier. The resulting modifier was designated as CMN-12.

[0065] Comparative Example 13

[0066] Different from Example 1, indium tin precursor was not added, and only WO3 nanorods were used for the assembly of the composite modifier. The resulting modifier was designated as CMN-13.

[0067] Comparative Example 14

[0068] Different from Example 5, the interfacial self-assembly was not carried out. Mesoporous silica nanoparticles, WO3@ITO core-shell structure, nitrogen-containing dispersant and sodium tetraborate buffer solution were directly mixed in a ratio of 1:1:0.05:0.2 and simply stirred. The resulting modifier was designated as CMN-14.

[0069] Comparative Example 15

[0070] Different from Example 5, the nitrogen-containing dispersant was not added, and only sodium tetraborate buffer solution was used for interfacial self-assembly. The resulting modifier was designated as CMN-15.

[0071] Table 2 Summary of missing components or process steps in Comparative Examples 1-15

[0072]

[0073] To verify the performance of the electroless copper plating nano-modifier (CMN) and its copper layer (Cu-0) prepared in Examples 1-20 and Comparative Examples 1-15 in the aMSAP process of SLP-type substrates, the following test methods were designed to evaluate the uniformity, adhesion, and antioxidant properties of the copper layer.

[0074] Test for copper layer uniformity: Method: Apply the modifiers prepared in Examples 1-20 and Comparative Examples 1-15 (or the blank copper layer in Comparative Example 1) to the electroless copper plating step of the aMSAP process for SLP-type substrates. Use a scanning electron microscope (SEM, model: Hitachi SU8220) to observe the surface morphology of the copper layer, and measure the standard deviation (SD) of the copper layer thickness as the uniformity index. Test conditions: Accelerating voltage 5 kV, magnification 5000 times, randomly select 5 fields of view, measure the thickness and calculate the SD. The smaller the SD, the better the uniformity of the copper layer. Test for copper layer adhesion: Method: Use a cross-cut tape test (ASTM D3359 standard). Use a cross-cut knife (1 mm spacing) to make 100 small grids on the surface of the copper-plated SLP substrate, stick 3M Scotch 600 tape, and quickly tear it off at a 45° angle after standing for 1 min. Count the number of peeled grids and calculate the adhesion rate (%). The higher the adhesion rate, the better the adhesion. Test for antioxidant properties: Method: Place the copper-plated SLP substrate in a high-temperature and high-humidity environment (85 °C, 85% relative humidity) for 48 h, and use X-ray photoelectron spectroscopy (XPS, model: Thermo Scientific Escalab 250Xi) to analyze the content of copper oxides (CuO and Cu2O) on the copper layer surface. Record the total content of copper oxide (mol%), and the lower the content, the better the antioxidant performance. Test conditions: XPS uses Al / Kα rays (1486.6 eV), scanning range 0-1200 eV, step size 0.1 eV. Experimental conditions: The electroless copper plating process is carried out under standard PTH (through-hole plating) conditions, and the plating solution composition is: copper sulfate pentahydrate 15 g / L, EDTA 30 g / L, formaldehyde 10 mL / L, pH 12.5, temperature 50 °C, plating time 30 min. The substrate is an SLP-type high-density interconnect board, with dimensions of 50 mm × 50 mm and a through-hole diameter of 100 μm. Modifier addition amount: 0.5 g / L plating solution (except for Comparative Example 1).

[0075] Performance tests of Examples 1-5 and Comparative Examples 1-3

[0076] According to the test method of Example 1, perform performance tests on the modifiers and copper layers prepared in Examples 1-5 and Comparative Examples 1-3, and record the copper layer uniformity (thickness standard deviation), adhesion (adhesion rate), and antioxidant properties (copper oxide content). The results are summarized in Table 3.

[0077] Table 3 Performance test results of Examples 1-5 and Comparative Examples 1-3

[0078] Sample Thickness standard deviation (μm) Adhesion rate (%) Copper oxide content (mol%) Example 1 (CMN) 0.12 98.5 2.1 Example 2 0.11 98.8 2.0 Example 3 0.10 99.0 1.9 Example 4 0.13 98.3 2.2 Example 5 0.14 98.0 2.3 Comparative Example 1 (Cu-0) 0.45 85.0 15.8 Comparative Example 2 (CMN-2) 0.28 90.2 8.5 Comparative Example 3 (CMN-3) 0.25 91.5 7.8

[0079] Analysis: The copper layers in Examples 1 - 5 have excellent uniformity (SD ≤ 0.14 μm), high adhesion (adhesion rate ≥ 98.0%), and strong antioxidant performance (copper oxide content ≤ 2.3 mol%), indicating that the modifier effectively improves the electroless copper plating performance. Comparative Example 1 (without modifier) has the worst performance, with a thickness standard deviation as high as 0.45 μm, an adhesion rate of only 85.0%, and a copper oxide content of 15.8 mol%, indicating that the modifier is crucial for improving the quality of the copper layer. In Comparative Example 2 (prepared without the template agent), since CTAB, P - 123, and cassava starch did not form a regular micelle structure, the pores of the mesoporous silica particles were uneven, affecting the dispersibility of the modifier and resulting in a performance decline (SD = 0.28 μm, copper oxide content 8.5 mol%). In Comparative Example 3 (without cassava starch), due to the lack of a light - responsive structure in the template agent, the pore - regulating ability of the mesoporous silica was weakened, and its uniformity and antioxidant performance were slightly better than those of Comparative Example 2 but still significantly inferior to those of the examples (SD = 0.25 μm, copper oxide content 7.8 mol%).

[0080] Performance tests of Examples 6 - 10 and Comparative Examples 4 - 5

[0081] According to the test method of Example 1, performance tests were carried out on Examples 6 - 10 and Comparative Examples 4 - 5, with a focus on investigating the role of the silane precursor preparation and its components. The results are summarized in Table 4.

[0082] Table 4 Performance test results of Examples 6 - 10 and Comparative Examples 4 - 5

[0083] Sample Thickness standard deviation (μm) Adhesion rate (%) Copper oxide content (mol%) Example 6 0.11 98.7 2.0 Example 7 0.12 98.5 2.1 Example 8 0.10 99.1 1.8 Example 9 0.13 98.4 2.2 Example 10 0.14 98.2 2.3 Comparative Example 4 (CMN-4) 0.30 89.5 9.2 Comparative Example 5 (CMN-5) 0.27 90.8 8.0

[0084] Analysis: Examples 6 - 10 maintained excellent copper layer performance (SD ≤ 0.14 μm, adhesion rate ≥ 98.2%, copper oxide content ≤ 2.3 mol%), indicating that the optimized ratio and preparation process of the silane precursor ensured the structural stability of the mesoporous silica. In Comparative Example 4 (without the silane precursor preparation), since TEOS, imidazoline silane, and 3 - mercaptopropyltrimethoxysilane were simply mixed and did not form a functionalized silane network, the interfacial bonding force between the modifier and the copper layer decreased (SD = 0.30 μm, adhesion rate 89.5%). In Comparative Example 5 (without 3 - mercaptopropyltrimethoxysilane), due to the lack of mercapto functionalization, the chemical activity of the silane precursor decreased, affecting the chemical bonding between the modifier and the copper layer, and its performance was slightly better than that of Comparative Example 4 but still poor (SD = 0.27 μm, copper oxide content 8.0 mol%).

[0085] Performance tests of Examples 11 - 14 and Comparative Examples 6 - 7

[0086] According to the testing method of Example 1, performance tests were carried out on Examples 11 - 14 and Comparative Examples 6 - 7 to investigate the role of the surface modifier. The results are summarized in Table 5.

[0087] Table 5 Performance test results of Examples 11 - 14 and Comparative Examples 6 - 7

[0088]

[0089]

[0090] Analysis: Examples 11 - 14 showed excellent copper layer performance (SD ≤ 0.13 μm, adhesion rate ≥ 98.4%, copper oxide content ≤ 2.2 mol%), indicating that the synergistic effect of 3 - aminopropyltriethoxysilane and vinyltrimethoxysilane enhanced the surface activity of mesoporous silica. In Comparative Example 6 (without surface modifier), due to the lack of surface functionalization, the interfacial binding force between mesoporous silica and WO3@ITO was weakened, resulting in poor dispersibility of the modifier and a significant decline in copper layer performance (SD = 0.32 μm, copper oxide content 10.5 mol%). In Comparative Example 7 (only using vinyltrimethoxysilane), due to the lack of amino functionalization and insufficient surface chemical activity, the performance was slightly better than that of Comparative Example 6 but still poor (SD = 0.29 μm, copper oxide content 9.8 mol%).

[0091] Performance tests of Examples 15 - 20 and Comparative Examples 8 - 11

[0092] According to the testing method of Example 1, performance tests were carried out on Examples 15 - 20 and Comparative Examples 8 - 11 to investigate the role of tungstate and indium tin precursor. The results are summarized in Table 6.

[0093] Table 6 Performance test results of Examples 15 - 20 and Comparative Examples 8 - 11

[0094] Sample Thickness standard deviation (μm) Adhesion rate (%) Copper oxide content (mol%) Example 15 0.11 98.9 2.0 Example 16 0.10 99.1 1.8 Example 17 0.12 98.7 2.1 Example 18 0.13 98.5 2.2 Example 19 0.14 98.3 2.3 Example 20 0.11 98.8 2.0 Comparative Example 8 (CMN-8) 0.31 88.5 10.2 Comparative Example 9 (CMN-9) 0.28 89.8 9.5 Comparative Example 10 (CMN-10) 0.33 87.5 11.0 Comparative Example 11 (CMN-11) 0.30 88.8 10.3

[0095] Analysis: Examples 15 - 20 maintained excellent performance (SD ≤ 0.14 μm, adhesion rate ≥ 98.3%, copper oxide content ≤ 2.3 mol%), indicating that the optimized preparation process of tungstate and indium tin precursor ensured the stability of the WO3@ITO core - shell structure. In Comparative Example 8 (lacking the preparation of tungstate precursor) and Comparative Example 9 (lacking cerium ammonium nitrate), due to the incomplete WO3 nanorod structure, the conductivity and antioxidant properties of the core - shell structure decreased, and the performance was poor (SD ≥ 0.28 μm, copper oxide content ≥ 9.5 mol%). In Comparative Example 10 (lacking the preparation of indium tin precursor) and Comparative Example 11 (lacking dibutyltin dilaurate), due to the ineffective formation of the ITO layer, the synergistic effect of the core - shell structure was lost, and the performance was the worst (SD ≥ 0.30 μm, copper oxide content ≥ 10.3 mol%).

[0096] Performance Tests of Examples 1, 5, 10 and Comparative Examples 12 - 15

[0097] According to the test method of Example 1, performance tests were carried out on Examples 1, 5, 10 and Comparative Examples 12 - 15 to investigate the effects of thermal coating and interfacial self - assembly. The results are summarized in Table 7.

[0098] Table 7 Performance Test Results of Examples 1, 5, 10 and Comparative Examples 12 - 15

[0099] Sample Thickness standard deviation (μm) Adhesion rate (%) Copper oxide content (mol%) Example 1 0.12 98.5 2.1 Example 5 0.14 98.0 2.3 Example 10 0.14 98.2 2.3 Comparative Example 12 (CMN-12) 0.35 87.0 11.5 Comparative Example 13 (CMN-13) 0.38 86.5 12.0 Comparative Example 14 (CMN-14) 0.29 89.0 9.8 Comparative Example 15 (CMN-15) 0.27 90.0 9.2

[0100] Analysis: Examples 1, 5, and 10 showed excellent performance (SD ≤ 0.14 μm, adhesion rate ≥ 98.0%, copper oxide content ≤ 2.3 mol%), indicating that the thermal coating and interfacial self - assembly processes ensured the structural integrity and functionality of the modifier. In Comparative Example 12 (lacking thermal coating), since the WO3 and indium - tin precursor did not form a core - shell structure, the synergistic effect was lost and the performance decreased significantly (SD = 0.35 μm, copper oxide content 11.5 mol%). In Comparative Example 13 (lacking indium - tin precursor), relying only on WO3 nanorods, lacking the conductivity and protective effect of ITO, had the worst performance (SD = 0.38 μm, copper oxide content 12.0 mol%). In Comparative Example 14 (lacking interfacial self - assembly) and Comparative Example 15 (lacking nitrogen - containing dispersant), due to the ineffective integration of modifier components, the dispersibility and interfacial binding force decreased, and the performance was poor (SD ≥ 0.27 μm, copper oxide content ≥ 9.2 mol%).

[0101] To simulate the durability of electroless copper plating in practical applications, the copper - plated substrates of Examples 1, 5, 10 and Comparative Examples 12 - 15 were placed under the following conditions for durability tests: High - temperature and high - humidity cycle: After aging at 85 °C and 85% relative humidity for 48 h, it was placed at 25 °C and 50% humidity for 2 h, and repeated 3 times. Mechanical damage: Punch holes on the copper layer surface with a metal needle of 1 mm diameter at a density of 10 per dm 2 Density. Acidic environment: Immersed in sulfuric acid solution with pH 4.0 for 48 h and then placed in deionized water for 2 h. After the test, the uniformity, adhesion and antioxidant performance were retested according to the method of Example 1, and the results are summarized in Table 8.

[0102] Table 8 Durability Test Results

[0103]

[0104]

[0105] Analysis: Examples 1, 5, and 10 still maintained excellent performance (SD ≤ 0.16 μm, adhesion rate ≥ 97.3%, copper oxide content ≤ 2.6 mol%) under high temperature and high humidity, mechanical damage, and acidic environment, indicating that the composite structure of the modifier has good durability and stability. In Comparative Examples 12 - 13, due to the lack of core-shell structure, the performance decreased significantly under harsh conditions (SD ≥ 0.40 μm, copper oxide content ≥ 14.5 mol%), indicating the importance of thermal coating and indium tin precursor for durability. In Comparative Examples 14 - 15, due to the absence of interfacial self-assembly or dispersant, the structural integrity of the modifier was poor and the durability was poor (SD ≥ 0.30 μm, copper oxide content ≥ 10.8 mol%). The electroless copper-plated nano-modifier of Examples 1 - 20 significantly improved the uniformity (SD ≤ 0.14 μm), adhesion (≥ 98.0%), and antioxidant performance (copper oxide content ≤ 2.3 mol%) of the copper layer by optimizing the template agent, silane precursor, surface modifier, tungstate precursor, indium tin precursor, and interfacial self-assembly process. Comparative Examples 1 - 15 verified the necessity of each component by lacking key components or process steps: The template agent and cassava starch ensure the pore structure and light responsiveness of mesoporous silica. The silane precursor and its functionalized components enhance the interfacial binding force. The surface modifier improves the dispersibility and chemical activity of the modifier. Tungstate and indium tin precursors form a stable WO3@ITO core-shell structure, enhancing conductivity and antioxidant properties. Thermal coating and interfacial self-assembly ensure the synergistic effect and stability of the composite structure. In addition, taking Example 8 as an example, as Figure 2 , Figure 3 and Figure 4 shown, it can be seen the transmission electron microscope images of the prepared mesoporous silica nanoparticles, the transmission electron microscope images of the prepared WO3@ITO core-shell structure, and the transmission electron microscope images of the prepared electroless copper-plated nano-modifier, indirectly indicating the success of the preparation.

[0106] The above content is a further detailed description of the present invention in combination with specific embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, which should all be regarded as belonging to the protection scope determined by the claims submitted for the present invention.

Claims

1. Preparation method of electroless copper plating nano modifier for SLP class carrier board aMSAP process, characterized in that: It includes the following steps: (1) Functionalization treatment of mesoporous silica support: Mix a template agent, a silane precursor, and a surface modifier in a mass ratio of 1:(0.5 - 2):(0.1 - 0.5), and carry out a hydrolysis and condensation reaction under alkaline conditions. After the reaction, mesoporous silica nanoparticles are obtained; (2) Construction of metal oxide core-shell structure: Prepare an aqueous solution by mixing a tungstate precursor, ammonium sulfate, and water in a mass ratio of (3 - 5):1:(15 - 20), adjust the pH to 1.5 - 2.5 for hydrothermal reaction to generate WO3 nanorods, and then perform thermal coating with an indium tin precursor in a mass ratio of (10 - 20):1 to form a WO3@ITO core-shell structure; (3) Assembly of composite modifier: Mix the mesoporous silica nanoparticles obtained in step (1) with the WO3@ITO core-shell structure obtained in step (2) in a mass ratio of (1 - 3):1, add a nitrogen-containing organic dispersant and a boric acid-based buffer solution, and carry out interfacial self-assembly under the action of an ultrasonic field to obtain a chemically copper-plated nano-modifier.

2. The preparation method of the electroless copper plating nano modifier for the aMSAP process of the SLP type carrier board according to claim 1, wherein: The preparation method of the template agent described in step (1) is as follows: Mix cetyltrimethylammonium bromide and poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer in a mass ratio of 1:(0.2 - 0.8), add an aqueous solution containing 0.5 - 2 wt% sodium tartrate with a mass 10 - 20 times that of cetyltrimethylammonium bromide, and perform ultrasonic dispersion at 50 - 70 °C for 40 - 60 min to form an amphiphilic composite micelle. Then add tapioca starch and mix, where the mass ratio between tapioca starch and cetyltrimethylammonium bromide is (0.2 - 0.6):

1. Then perform a stepped temperature treatment: The first stage: maintain at 65 - 75 °C for 30 - 60 min, the second stage: rapidly cool to 0 - 5 °C and maintain for 10 - 15 min, the third stage: heat up at a rate of 2 - 5 °C / min to 40 - 50 °C. After the stepped temperature treatment, soak with an ethanol solution containing 0.1 - 0.5 mol / L citric acid, and then perform ultraviolet curing treatment under nitrogen protection to obtain a template agent with light-responsive characteristics.

3. The preparation method of the electroless copper plating nano modifier for the aMSAP process of the SLP type carrier board according to claim 1, characterized in that: The preparation method of the silane precursor in step (1) is as follows: Mix tetraethoxysilane and triethoxy-3-(2-imidazolin-1-yl)propylsilane in a molar ratio of (5 - 8):1, add an ethanol solution containing 1 - 2 wt% 1,8-diazabicycloundec-7-ene with a mass 5 - 10 times that of tetraethoxysilane, and carry out a hydrolysis reaction under anaerobic conditions. Then, introduce 3-mercaptopropyltrimethoxysilane into the product of the hydrolysis reaction, where the molar ratio between 3-mercaptopropyltrimethoxysilane and tetraethoxysilane is (0.3 - 0.6):

1. Adopt a microwave-assisted synthesis method: power density: 50 - 100 W / L, pressure control: 0.5 - 2 MPa, reaction time: 10 - 30 min. Finally, soak with an acetone solution containing 0.1 - 0.5 wt% benzotriazole, and then initiate crosslinking under ultraviolet light.

4. The preparation method of the electroless copper plating nano modifier for the aMSAP process of the SLP type carrier board according to claim 1, characterized in that: In step (1), the surface modifier is a mixed solution of 3-aminopropyltriethoxysilane and vinyltrimethoxysilane in a molar ratio of (0.5 - 2):1; the parameters for the hydrolysis and condensation reaction under alkaline conditions in step (1) are as follows: pH value 10 - 12, temperature 60 - 80 °C, reaction time 2 - 4 h, stirring speed 500 - 1000 rpm.

5. The preparation method of the electroless copper plating nano modifier for the aMSAP process of the SLP type carrier board according to claim 1, characterized in that: In step (2), the preparation method of the tungstate precursor is as follows: Mix ammonium metatungstate and silicotungstic acid in a mass ratio of (3 - 5):1, add an ethylene glycol solution containing 0.1 - 0.5 mol / L ascorbic acid and 15 - 20 times the mass of ammonium metatungstate, and carry out the reaction under microwave assistance. The power of the reaction is 200 - 400 W, the reaction temperature is 80 - 120 °C, and the reaction time is 10 - 30 min. Then, add ammonium cerium nitrate with a mass 0.2 - 0.6 times that of ammonium metatungstate and treat it through ultrasonic cavitation effect. The frequency of the ultrasonic cavitation effect is 20 - 40 kHz, and the power density is 50 - 100 W / L. Subsequently, adopt a staged hydrothermal crystallization process: The first stage: maintain at 100 - 120 °C for 4 - 6 h, the second stage: rapidly heat up to 180 - 200 °C and hold for 0.5 - 1 h, the third stage: gradually cool down to 80 - 100 °C to obtain the tungstate precursor; the parameters of the hydrothermal reaction in step (2) are as follows: 120 - 140 °C, 6 - 10 h.

6. The preparation method of the electroless copper plating nano modifier for the aMSAP process of the SLP type carrier board according to claim 1, characterized in that: In step (2), the preparation method of the indium tin precursor is as follows: Mix indium acetylacetonate and dibutyltin dilaurate in a molar ratio of (3 - 5):2, add an ethylene glycol solution containing 10 - 20 wt% dodecyl mercaptan and 5 - 8 times the mass of indium acetylacetonate, and then carry out microwave treatment. The parameters of the microwave treatment are as follows: power 300 - 500 W, temperature 120 - 150 °C, pressure 0.5 - 1.5 MPa, to obtain the indium tin precursor.

7. The preparation method of the electroless copper plating nano modifier for the aMSAP process of the SLP type carrier board according to claim 1, wherein: In step (2), the parameters of the thermal coating are as follows: Adopt an asymmetric three-stage temperature control program. Nucleation stage: maintain at 120 - 150 °C for 0.5 - 1 h, crystallization stage: hold at 180 - 220 °C for 2 - 4 h, pressure 0.5 - 1.5 MPa, annealing stage: cool down to 80 - 100 °C at a rate of 5 °C / min.

8. The preparation method of the electroless copper plating nano modifier for the aMSAP process of the SLP type carrier board according to claim 1, characterized in that: In step (3), the nitrogen-containing organic dispersant is oil-based aminoethylimidazoline, and the final mass percentage of the nitrogen-containing organic dispersant is 5 - 10%; in step (3), the borate buffer solution is a 0.05 - 0.2 M sodium tetraborate solution, and the mass ratio between it and the nitrogen-containing organic dispersant is 10:(2 - 3); in step (3), the parameters of the ultrasonic field are as follows: frequency 10 - 20 MHz, 30 - 45 min.

9. A electroless copper plating nano modifier for aMSAP process of SLP class carrier board, characterized in that, The electroless copper plating nano-modifier for the SLP type carrier board aMSAP process described above is obtained by the preparation method according to any one of claims 1 - 8.

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