A nano-modifier for electroless copper plating using SLP-type substrates in aMSAP process and its preparation method

Abstract

This invention discloses a nano-modifier for electroless copper plating in the aMSAP process of SLP-type substrates and its preparation method, belonging to the field of new materials technology. Addressing the problems of poor copper layer uniformity, weak adhesion, insufficient oxidation resistance, and poor durability in existing electroless copper plating technologies, this invention designs a nano-modifier comprising a template agent, a silane precursor, a surface modifier, and a WO3@ITO core-shell structure, and prepares it using a template agent-assisted sol-gel method, thermal coating, and interface self-assembly process. This modifier significantly improves copper layer performance, with a thickness standard deviation ≤0.14μm, adhesion rate ≥98.0%, copper oxide content ≤2.3mol%, and minimal performance degradation after durability testing. The preparation process is simple, requires low dosage, is highly compatible with the aMSAP process, is low-cost and environmentally friendly, and meets the high-density interconnect and high-reliability manufacturing requirements of SLP-type substrates, demonstrating significant industrial application value.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology, specifically, it relates to a chemical copper plating nanomodifier for SLP-type substrate aMSAP process and its preparation method. Background Technology

[0002] With the rapid development of the electronics and information industry, high-density interconnect (HDI) boards, as core components of high-performance electronic products such as smartphones, tablets, 5G communication equipment, and wearable devices, face increasingly stringent requirements for their manufacturing processes. Substrate-like PCB (SLP), an advanced HDI technology, significantly improves the integration and signal transmission efficiency of circuit boards by refining linewidth / spacing (typically ≤30μm / 30μm) and using high-density via designs. Advanced Modified Semi-Additive Process (aMSAP), a key technology in SLP manufacturing, forms a fine conductive copper layer on the substrate surface through chemical copper plating and electroplating processes, meeting the demands of high-density wiring and complex three-dimensional structures. However, as the initial step in the aMSAP process, the performance of chemical copper plating directly determines the quality of subsequent electroplating and the reliability of the final product. Therefore, developing high-performance chemical copper plating technology is both a key focus and a challenge in the field of SLP-like substrate manufacturing.

[0003] Electroless copper plating technology deposits a uniform copper film on the surface of a non-conductive substrate (such as resin, ceramic, or glass fiber) to provide a conductive seed layer for subsequent electroplating. Its core lies in the performance of the catalyst or modifier; the catalyst must possess high dispersibility, strong interfacial bonding, and excellent catalytic activity to ensure the uniformity, adhesion, and long-term stability of the copper layer. Traditional electroless copper plating processes typically use noble metal catalysts (such as palladium-based catalysts) or simple metal oxides (such as CuO, TiO2), combined with a single support material (such as silica or polymer microspheres) to promote copper ion reduction and deposition. However, existing technologies suffer from the following significant problems in practical applications: Insufficient copper layer uniformity: The limited dispersibility and interfacial reaction control of existing electroless copper plating catalysts lead to uneven copper layer thickness distribution. Literature and experimental data show that the standard deviation (SD) of copper layer thickness prepared by traditional processes is typically between 0.25-0.45 μm, especially on surfaces with high aspect ratio through-holes or complex substrates, where localized areas of excessive thickness or thinness are prone to occur. This not only increases the difficulty of subsequent electroplating but may also lead to inconsistent signal transmission impedance, affecting the electrical performance of SLP-type substrates. Weak copper layer adhesion: In existing technologies, the interfacial chemical bonding between the catalyst and the substrate or copper layer is insufficient, with adhesion rates typically below 91.5% in cross-cut adhesion tests. Under 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 substrates in high-reliability scenarios (such as automotive electronics and aerospace). Insufficient oxidation resistance: Chemically plated copper layers are prone to oxidation in high-temperature and high-humidity environments (such as 85℃, 85% humidity), with copper oxide content reaching as high as 7.8-15.8 mol%, leading to decreased conductivity and shortened device lifespan. This is particularly critical in high-performance electronic products because the oxide layer significantly increases contact resistance, reducing the long-term stability of the circuit board. Insufficient durability: Existing chemically plated copper layers exhibit significant performance degradation under extreme conditions (such as high-temperature and high-humidity cycling, mechanical damage, or acidic environments). Experiments show that after durability testing, the copper layer prepared by traditional processes exhibits a thickness standard deviation exceeding 0.30 μm, an adhesion rate below 87.5%, and a significantly increased copper oxide content (≥10.8 mol%). This fails to meet the high reliability requirements of SLP-type carriers in harsh environments. Process complexity and cost issues: The preparation process of traditional chemical copper plating catalysts is relatively complex, requiring high-concentration catalysts (>1.0 g / L) to achieve limited performance improvements, increasing production costs. Furthermore, some catalysts (such as palladium-based catalysts) rely on precious metals, making them expensive, and the organic solvents or chemical additives used in the preparation process are environmentally unfriendly, limiting the application prospects of green manufacturing. Insufficient synergy between components and processes: Existing catalysts or modifiers typically employ single functional components (such as simple metal oxides or inorganic supports), lacking multi-component synergistic optimization, resulting in low catalytic efficiency and poor dispersibility.Traditional preparation processes (such as simple mixing or physical deposition) cannot achieve precise control of catalyst structure, making it difficult to achieve uniform and stable copper layer deposition on the complex substrate surface of SLP-type carriers.

[0004] To address the aforementioned issues, researchers have recently attempted to improve the performance of electroless copper plating by modifying catalyst components and preparation processes. For example, some studies have introduced nanocomposite materials (such as SiO2@metal oxide) as catalyst supports to improve dispersibility and catalytic activity; others have used surface modification techniques to enhance the adhesion between the copper layer and the substrate. However, these methods still have limitations: the irregular pore structure of a single support material makes it difficult to achieve uniform deposition of copper ions; the selection and functionalization of surface modifiers are insufficient, making it difficult to balance adhesion and oxidation resistance; furthermore, the lack of precise control over the catalyst's microstructure results in limited performance improvement, making it difficult to meet the requirements of high uniformity, high adhesion, and long lifespan for SLP-type substrate aMSAP processes. Summary of the Invention

[0005] 1. The problem to be solved

[0006] To address the shortcomings of existing technologies in the aMSAP process for SLP-type substrates regarding the uniformity, adhesion, oxidation resistance, durability, and economic efficiency of electroless copper plating, this invention designs novel electroless copper plating nanomodifiers and their preparation methods, optimizes key components (such as template agents, silane precursors, and WO3@ITO core-shell structures) and process steps (such as thermal coating and interface self-assembly), aiming to significantly improve copper layer performance and meet the requirements of high reliability and low-cost manufacturing of high-density interconnect boards.

[0007] 2. Technical Solution

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

[0009] A method for preparing a chemical copper plating nanomodifier for SLP-type substrate aMSAP process includes the following steps: (1) Functionalization treatment of mesoporous silica carrier: The template agent, silane precursor and surface modifier are mixed in a mass ratio of 1:(0.5-2):(0.1-0.5), and a hydrolysis condensation reaction is carried out under alkaline conditions to obtain mesoporous silica nanoparticles after the reaction; (2) Construction of metal oxide core-shell structure: The tungstate precursor, ammonium sulfate and water are prepared into an aqueous solution in a mass ratio of (3-5):1:(15-20). The pH was adjusted to 1.5-2.5 to carry out a hydrothermal reaction to generate WO3 nanorods, which were then thermally coated with indium tin precursor at a mass ratio of (10-20):1 to form a WO3@ITO core-shell structure; (3) Composite modifier assembly: The mesoporous silica nanoparticles obtained in step (1) and the WO3@ITO core-shell structure obtained in step (2) were mixed at a mass ratio of (1-3):1, and nitrogen-containing organic dispersant and boric acid buffer were added. The interface self-assembly was carried out under the action of an ultrasonic field to obtain a chemical copper plating nanomodifier.

[0010] The preparation method of the chemical copper plating nanomodifier for the SLP-type carrier aMSAP process, the preparation method of the template agent in step (1) is as follows: hexadecyltrimethylammonium bromide (CAS No. 57-09-0) and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (CAS No. 9003-11-6, BASF Pluronic type P-123 (PEO-PPO-PEO)) are mixed at a mass ratio of 1:(0.2-0.8), and 10-20 times the mass of hexadecyltrimethylammonium bromide is added to an aqueous solution containing 0.5-2wt% sodium tartrate (CAS No. 868-18-8), and the mixture is prepared at 50-70℃. The mixture was ultrasonically dispersed at 120W for 40-60 minutes to form amphiphilic complex micelles. Then, cassava starch (CAS No. 9005-25-8, 100 mesh, source: 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 12.40μm) was added and mixed. The mass ratio of cassava starch to hexadecyltrimethylammonium bromide was (0.2-0.6):1. The mixture was then subjected to a stepped temperature treatment (using a reactor with a temperature control unit, such as the CORIO manufactured by Julabo Corporation, USA). CD-200F): First stage: 65-75℃ for 30-60 min; Second stage: Rapidly cool to 0-5℃ and maintain for 10-15 min; Third stage: Heat to 40-50℃ at a rate of 2-5℃ / min. After this stepped temperature treatment, the product is obtained and 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 the mass of the product. Subsequently, it undergoes ultraviolet curing under nitrogen protection. Ultraviolet light source: UV-A, wavelength 365nm, light intensity: 20mW / cm². 2 Irradiation time: 15 min, nitrogen protection: flow rate 1 L / min, purity 99.999%, curing temperature: 25℃, to obtain a template agent with photoresponsive properties.

[0011] The preparation method of the SLP-type carrier aMSAP process for chemical copper plating nanomodifier, 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 at a molar ratio of (5-8):1, and 5-10 times the mass of tetraethoxysilane is added to an ethanol solution containing 1-2 wt% 1,8-diazabicycloundec-7-ene (CAS No. 6674-22-2). Hydrolysis reaction is carried out under anaerobic conditions (nitrogen protection), wherein the parameters of the hydrolysis reaction are as follows: temperature 45-50℃, 2-4h. Next, 3-mercaptopropyltrimethoxysilane (CAS No. 4420-74-0) was introduced into the product of the hydrolysis reaction, wherein the molar ratio of 3-mercaptopropyltrimethoxysilane to tetraethoxysilane was (0.3-0.6):1. Microwave-assisted synthesis was employed: power density: 50-100 W / L, pressure control: 0.5-2 MPa, reaction time: 10-30 min. Finally, the mixture was soaked in an acetone solution containing 0.1-0.5 wt% benzotriazole (CAS No. 95-14-7), wherein the mass of the acetone solution was 20-30 times that of the tetraethoxysilane. Crosslinking was then initiated under ultraviolet light: UV-A, wavelength 312 nm, light intensity: 25 mW / cm². 2 Irradiation time: 30 min, nitrogen protection: flow rate 1 L / min, purity 99.999%, crosslinking temperature: 45℃.

[0012] Preferably, in step (1), the surface modifier is a mixture 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 for the hydrolysis-condensation reaction under alkaline conditions in step (1) are as follows: pH value 10-12, temperature 60-80℃, reaction time 2-4h, and stirring speed 500-1000rpm.

[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. An ethylene glycol solution containing 0.1-0.5 mol / L ascorbic acid (CAS No. 50-81-7) is added at 15-20 times the mass of ammonium metatungstate. The reaction is carried out under microwave assistance, with a reaction power of 200-400 W, a reaction temperature of 80-120 °C, and a reaction time of 10-30 min. Then, cerium ammonium nitrate (CAS No. 16774-21-3) is added at 0.2-0.6 times the mass of ammonium metatungstate. The reaction is then carried out using ultrasonic cavitation (Branson Sonic). The process is performed using a fier series ultrasonic generator (such as SFX250), where the frequency of the ultrasonic cavitation effect is 20-40kHz and the power density is 50-100W / L. Then, a staged hydrothermal crystallization process is adopted: the first stage: 100-120℃ for 4-6h, the second stage: rapidly heating to 180-200℃ and holding for 0.5-1h, the third stage: gradient cooling to 80-100℃ to obtain the tungstate precursor; the parameters of the hydrothermal reaction in step (2) are as follows: 120-140℃, 6-10h.

[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 10-20wt% dodecyl mercaptan (CAS No. 112-55-0) is added at 5-8 times the mass of indium acetylacetonate. Then, microwave treatment is performed, wherein the parameters of microwave treatment are as follows: power 300-500W, temperature 120-150℃, pressure 0.5-1.5MPa, to obtain the indium tin precursor.

[0015] Preferably, the parameters for heat coating in step (2) are as follows: an asymmetric three-stage temperature control program is used (e.g., a common PID temperature controller, AI-708P type equipment produced by Xiamen Yudian Automation Technology Co., Ltd.), nucleation stage: 120-150℃ for 0.5-1h, crystallization stage: 180-220℃ for 2-4h, pressure 0.5-1.5MPa, annealing stage: cooling to 80-100℃ at a rate of 5℃ / min.

[0016] Preferably, the nitrogen-containing organic dispersant in step (3) is oleo-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 buffer solution in step (3) is a 0.05-0.2M 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 10-20MHz, 30-45min.

[0017] A nano-modifier for electroless copper plating in the aMSAP process of SLP-type substrates is obtained by the preparation method described above.

[0018] 3. Beneficial effects

[0019] Compared to existing technologies, the beneficial effects of this invention are as follows: Significantly improved copper layer uniformity: This invention optimizes the ratio of template agents (CTAB, P-123, and tapioca starch) and silane precursors (TEOS, imidazoline silane, 3-mercaptopropyltrimethoxysilane) to prepare a silica carrier with a regular mesoporous structure. Combined with the WO3@ITO core-shell structure and interface self-assembly process, the chemical copper plating nanomodifier (CMN) forms a highly uniform copper layer in the aMSAP process of SLP-type substrates. Tests in 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, with a uniformity improvement of approximately 68.9%-72.2%. This effectively reduces thickness deviation in through-hole plating and improves the reliability of high-density interconnect boards. Enhanced Copper Layer Adhesion: This invention enhances the interfacial chemical bonding between the modifier and the copper layer through the synergistic effect of surface modifiers (3-aminopropyltriethoxysilane and vinyltrimethoxysilane) and functionalized silane precursors. Cross-cut adhesion tests in Examples 2-6 show that the copper layer adhesion rate in Examples 1-20 is ≥98.0%, an improvement of approximately 13.6%-15.3% compared to Comparative Example 1 (85.0%) and Comparative Examples 2-15 (86.5%-91.5%), significantly reducing the risk of copper layer peeling and meeting the stability requirements of SLP-type substrates under complex stress environments. Excellent Antioxidant Properties: This invention utilizes a WO3@ITO core-shell structure and a thermal coating process to endow the modifier with excellent antioxidant protection capabilities. XPS tests in Examples 2-6 showed that the copper oxide content of the copper layers in Examples 1-20 after aging at 85°C and 85% humidity for 48 hours was ≤2.3 mol%, far lower than the 15.8 mol% of Comparative Example 1 and the 7.8-12.0 mol% of Comparative Examples 2-15, with an improvement in oxidation resistance of approximately 85.4%-87.7%. This effectively extends the service life of the copper layers, making them suitable for the manufacture of high-reliability electronic devices. Excellent durability: This invention optimizes the structural integration of the modifier through thermal coating and interface self-assembly processes, enabling the copper layers to maintain excellent performance even under harsh conditions. Durability tests in Example 7 showed that Examples 1, 5, and 10 exhibited good performance under high-temperature and high-humidity cycling (85°C, 85% humidity) and mechanical damage (10 cycles / dm³). 2After perforation and exposure to an acidic environment (pH 4.0, 48h), the thickness standard deviation is ≤0.16μm, the adhesion rate is ≥97.3%, and the copper oxide content is ≤2.6mol%. In contrast, the performance of comparative examples 12-15 significantly decreased (SD≥0.30μm, adhesion rate≤87.5%, copper oxide content≥10.8mol%). Durability is improved by approximately 46.7%-50.0%, ensuring the stability of SLP-type carriers during long-term use. Process compatibility and environmental adaptability: The modifier preparation process of this invention (template agent-assisted sol-gel method, thermal coating, interface self-assembly) is simple to operate, compatible with existing aMSAP processes, and requires no additional equipment or complex steps. A modifier addition of only 0.5g / L can significantly improve performance, with low cost, suitable for large-scale production. Simultaneously, the natural components such as cassava starch in the modifier improve environmental friendliness and reduce the generation of chemical waste. Synergistic Effect of Key Components: Comparisons in Examples 2-6 demonstrate that the synergistic effect of the template agent, silane precursor, surface modifier, tungstate, and indium tin precursor is crucial for performance enhancement. Comparative Examples 1-15 show a significant performance degradation due to the absence of any key component or process step (such as template agent, thermal coating, or interfacial self-assembly), validating the necessity of each component and the scientific validity 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. Attached Figure Description

[0020] Figure 1 This is a flowchart of the preparation method of the chemical copper plating nanomodifier for the aMSAP process of SLP-type carriers in this invention.

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

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

[0023] Figure 4 This is a transmission electron microscope (TEM) image of the chemical copper plating nanomodifier prepared in Example 8. Detailed Implementation

[0024] The present invention will now be described in detail through specific embodiments. However, the uses and purposes of these illustrative embodiments are merely for illustrating the invention and do not constitute any limitation on the actual scope of protection of the invention, nor are they intended to limit the scope of protection of the invention to these embodiments. For parameter ranges not mentioned, intermediate values ​​are selected. Furthermore, for mass percentages or weight percentages not explicitly stated or mentioned, the final concentration after addition is generally referred to. Additionally, for mass fractions or weight parts involved, grams can be used in application.

[0025] The information on the substances involved is as follows: hexadecyltrimethylammonium bromide (CTAB): CAS No. 57-09-0; polyethylene oxide-polypropylene oxide-polyethylene 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...) Expansion 10.35%, solubility 28.00%, relative crystallinity 26.49%, short-range ordered structure infrared ratio 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-diazabicyclohexane -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. 1202 7-38-2; Ascorbic acid: CAS No. 50-81-7; Cerium ammonium nitrate: CAS No. 16774-21-3; Indium acetylacetone: CAS No. 14405-45-9; Dibutyltin dilaurate: CAS No. 77-58-7; Dodecyl mercaptan: CAS No. 112-55-0; Oleylamine ethyl imidazoline: CAS No. 25749-86-4; Sodium tetraborate: CAS No. 1330-43-4.

[0026] Reference Figure 1 The preparation flow chart shown illustrates that this invention provides a method for preparing a chemical copper plating nanomodifier for SLP-type substrate aMSAP process, and the technical solution is as follows.

[0027] Example 1

[0028] Template preparation: 1 part hexadecyltrimethylammonium bromide (CTAB) was mixed with 0.2 parts polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P-123), and 10 parts of an aqueous solution containing 0.5 wt% sodium tartrate were added. The mixture was ultrasonically dispersed at 50°C and 120 W for 40 min to form amphiphilic composite micelles. 0.2 parts cassava starch (to CTAB mass ratio of 0.2:1) were added, and a stepped temperature treatment was performed (using a Julabo CORIO CD-200F reactor with a temperature control unit): the first stage was held at 65°C for 30 min, the second stage was rapidly cooled to 0°C and held for 10 min, and the third stage was heated to 40°C at a rate of 2°C / min. After treatment, the product was soaked in an ethanol solution containing 0.1 mol / L citric acid (20 times the mass of the product) and then cured under nitrogen protection (1 L / min flow rate, 99.999% purity) using ultraviolet light (UV-A, 365 nm, 20 mW / cm²). 2 (15 min, curing temperature 25℃) to obtain a photoresponsive template agent.

[0029] Preparation of silane precursor: 5 parts of tetraethoxysilane (TEOS) and 1 part of triethoxy-3-(2-imidazolin-1-yl)propylsilane (molar ratio 5:1) were mixed, and 25 parts of an ethanol solution containing 1 wt% DBU were added. The mixture was hydrolyzed at 45 °C for 2 h under nitrogen protection (flow rate 1 L / min, purity 99.999%). 0.3 parts of 3-mercaptopropyltrimethoxysilane (molar ratio to TEOS 0.3:1) were added to the product, and the mixture was synthesized using microwave-assisted synthesis (50 W / L, 0.5 MPa, 10 min). The mixture was then soaked in an acetone solution containing 0.1 wt% benzotriazole (20 times the mass of TEOS) and exposed to ultraviolet light (UV-A, 312 nm, 25 mW / cm²). 2 Crosslinking was initiated by 30 min under nitrogen protection, flow rate 1 L / min, purity 99.999%, and crosslinking temperature 45℃ to obtain the silane precursor.

[0030] Functionalization of mesoporous silica carriers: 1 part template agent, 0.5 part silane precursor, and 0.1 part surface modifier (3-aminopropyltriethoxysilane and vinyltrimethoxysilane in a molar ratio of 0.5:1) were mixed and hydrolyzed and condensed for 2 hours at pH 10, 60℃ and a stirring speed of 500 rpm to obtain mesoporous silica nanoparticles.

[0031] Preparation of tungstate precursor: 3 parts ammonium metatungstate and 1 part silicotungstic acid were mixed, and 45 parts ethylene glycol solution containing 0.1 mol / L ascorbic acid were added. The reaction was carried out under microwave assistance (200 W, 80 °C, 10 min). 0.6 parts cerium ammonium nitrate were added, and the mixture was treated by ultrasonic cavitation (20 kHz, 50 W / L). A staged hydrothermal crystallization was then performed: the first stage was maintained at 100 °C for 4 h, the second stage was rapidly heated to 180 °C and held for 0.5 h, and the third stage was gradually cooled to 80 °C to obtain the tungstate precursor.

[0032] Preparation of indium tin precursor: 3 parts of indium acetylacetonate and 2 parts of dibutyltin dilaurate (molar ratio 3:2) were mixed, and 15 parts of ethylene glycol solution containing 10 wt% dodecyl mercaptan were added. The mixture was microwaved (300 W, 120 °C, 0.5 MPa) to obtain the indium tin precursor.

[0033] Construction of metal oxide core-shell structure: A solution was prepared by mixing 3 parts tungstate precursor, 1 part ammonium sulfate, and 15 parts water, and the pH was adjusted to 1.5. The solution was then subjected to hydrothermal reaction at 120℃ for 6 h to generate WO3 nanorods. The WO3 nanorods were then thermally coated with indium tin precursor (mass ratio 10:1) (nucleation: 120℃, 0.5 h; crystallization: 180℃, 2 h, 0.5 MPa; annealing: cooling to 80℃ at 5℃ / min) to form a WO3@ITO core-shell structure.

[0034] Composite modifier assembly: 1 part of mesoporous silica nanoparticles and 1 part of WO3@ITO core-shell structure were mixed, and a dispersant containing 5 wt% oleo-based aminoethyl imidazoline and 0.05 M sodium tetraborate buffer (mass ratio 10:2) were added. The interface self-assembled for 30 min under the action of a 10 MHz ultrasonic field to obtain a chemical copper plating nanomodifier (hereinafter referred to as CMN).

[0035] Example 2-20

[0036] Examples 2-20 follow the process flow and experimental methods of Example 1, but some parameters have been 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] Unlike Example 1, no chemical copper plating nanomodifier was prepared. Instead, the chemical copper plating step in the SLP-type substrate aMSAP process was directly performed, and the resulting copper layer was called Cu-0.

[0043] Comparative Example 2

[0044] Unlike Example 1, no template agent was prepared. Instead, CTAB, P-123 and cassava starch were mixed in a ratio of 1:0.2:0.2 and then added to an aqueous solution containing 0.5 wt% sodium tartrate. After simple stirring, the mixture was used for the functionalization of mesoporous silica carriers. The resulting modifier was called CMN-2.

[0045] Comparative Example 3

[0046] Unlike Example 1, no cassava starch was added. Instead, a template agent was prepared by mixing CTAB and P-123 at a ratio of 1:0.2. The resulting modifier was called CMN-3.

[0047] Comparative Example 4

[0048] Unlike Example 5, no silane precursor preparation was performed. Instead, TEOS, triethoxy-3-(2-imidazolin-1-yl)propylsilane and 3-mercaptopropyltrimethoxysilane were directly mixed in a molar ratio of 5:1:0.3 and used for the functionalization of mesoporous silica carriers. The resulting modifier was called CMN-4.

[0049] Comparative Example 5

[0050] Unlike Example 5, 3-mercaptopropyltrimethoxysilane was not added. Instead, a silane precursor was prepared using only TEOS and triethoxy-3-(2-imidazolin-1-yl)propylsilane in a 5:1 molar ratio. The resulting modifier was called CMN-5.

[0051] Comparative Example 6

[0052] Unlike Example 10, no surface modifier treatment was performed. Instead, a mesoporous silica carrier was functionalized by mixing a template agent and a silane precursor at a ratio of 1:0.5. The resulting modifier was called CMN-6.

[0053] Comparative Example 7

[0054] Unlike Example 10, 3-aminopropyltriethoxysilane was not added; instead, vinyltrimethoxysilane was used as the surface modifier, and the resulting modifier was called CMN-7.

[0055] Comparative Example 8

[0056] Unlike Example 15, no tungstate precursor was prepared. Instead, ammonium metatungstate, silicotungstic acid, and cerium ammonium nitrate were directly mixed in a ratio of 3:1:0.6 and used to construct the metal oxide core-shell structure. The resulting modifier was called CMN-8.

[0057] Comparative Example 9

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

[0059] Comparative Example 10

[0060] Unlike Example 20, instead of preparing an indium tin precursor, indium acetylacetone and dibutyltin dilaurate were directly mixed in a 3:2 molar ratio and then used for heat coating. The resulting modifier was called CMN-10.

[0061] Comparative Example 11

[0062] Unlike Example 20, dibutyltin dilaurate was not added; instead, indium tin precursor was prepared using only indium acetylacetone, and the resulting modifier was called CMN-11.

[0063] Comparative Example 12

[0064] Unlike Example 1, no thermal coating treatment was performed. Instead, WO3 nanorods and indium tin precursor were simply blended at a ratio of 10:1 and then used for the assembly of composite modifiers. The resulting modifier was called CMN-12.

[0065] Comparative Example 13

[0066] Unlike Example 1, no indium tin precursor was added; instead, WO3 nanorods were used for composite modification assembly, and the resulting modifier was called CMN-13.

[0067] Comparative Example 14

[0068] Unlike Example 5, no interfacial self-assembly was performed. Instead, mesoporous silica nanoparticles, WO3@ITO core-shell structure, nitrogen-containing dispersant and sodium tetraborate buffer were directly mixed at a ratio of 1:1:0.05:0.2 and then simply stirred. The resulting modifier was called CMN-14.

[0069] Comparative Example 15

[0070] Unlike Example 5, no nitrogen-containing dispersant was added; instead, interfacial self-assembly was performed using only sodium tetraborate buffer solution. The resulting modifier was named 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 nanomodifier (CMN) and its copper layer (Cu-O) 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 oxidation resistance of the copper layer.

[0074] Copper Layer Uniformity Test: Method: The modifiers prepared in Examples 1-20 and Comparative Examples 1-15 (or the blank copper layer of Comparative Example 1) were applied to the chemical copper plating step of the aMSAP process on SLP-type substrates. The surface morphology of the copper layer was observed using a scanning electron microscope (SEM, model: Hitachi SU8220), and the standard deviation (SD) of the copper layer thickness was measured as an indicator of uniformity. Test conditions: accelerating voltage 5kV, magnification 5000x, 5 fields of view were randomly selected, the thickness was measured, and the SD was calculated. The smaller the SD, the better the copper layer uniformity. Copper Layer Adhesion Test: Method: A cross-cut adhesion test (ASTM D3359 standard) was used. 100 small squares were drawn on the surface of the copper-plated SLP substrate using a cross-cut adhesion tester (1mm spacing), 3M Scotch 600 tape was applied, left to stand for 1 minute, and then quickly peeled off at a 45° angle. The number of peeled squares was counted, and the adhesion rate (%) was calculated. The higher the adhesion rate, the better the adhesion. Antioxidant Performance Test: Method: The copper-plated SLP substrate was aged in a high-temperature and high-humidity environment (85℃, 85% relative humidity) for 48 hours. The content of oxides (CuO and Cu2O) on the copper layer surface was analyzed using X-ray photoelectron spectroscopy (XPS, Thermo Scientific Escalab 250Xi). The total copper oxide content (mol%) was recorded; the lower the content, the better the antioxidant performance. Test Conditions: XPS used Al / Kα rays (1486.6 eV), with a scan range of 0-1200 eV and a step size of 0.1 eV. Experimental Conditions: The chemical copper plating process was carried out under standard PTH (through-hole plating) conditions. The plating solution composition was: copper sulfate pentahydrate 15 g / L, EDTA 30 g / L, formaldehyde 10 mL / L, pH 12.5, temperature 50℃, and plating time 30 min. The substrate was 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] Following the test method of Example 1, the modifiers and copper layers prepared in Examples 1-5 and Comparative Examples 1-3 were subjected to performance tests, and the uniformity of the copper layer (thickness standard deviation), adhesion (adhesion rate), and antioxidant properties (copper oxide content) were recorded. 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 exhibited excellent uniformity (SD≤0.14μm), high adhesion (adhesion rate≥98.0%), and strong oxidation resistance (copper oxide content≤2.3mol%), indicating that the modifier effectively improved the performance of electroless copper plating. Comparative Example 1 (without modifier) ​​showed the worst performance, with a thickness standard deviation as high as 0.45μm, an adhesion rate of only 85.0%, and a copper oxide content of 15.8mol%, demonstrating the crucial role of the modifier in improving the quality of the copper layer. In Comparative Example 2 (prepared without template agent), the lack of a regular micelle structure formed by CTAB, P-123, and cassava starch led to uneven porosity of the mesoporous silica particles, affecting the dispersibility of the modifier and resulting in decreased performance (SD=0.28μm, copper oxide content 8.5mol%). Comparative Example 3 (lacking cassava starch) lacked a photoresponsive structure in its template agent, resulting in a weakened ability to regulate the pore size of the mesoporous silica. Its uniformity and antioxidant properties were slightly better than those of Comparative Example 2, but still significantly worse than those of the Example (SD = 0.25 μm, copper oxide content 7.8 mol%).

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

[0081] Following the test method of Example 1, performance tests were conducted on Examples 6-10 and Comparative Examples 4-5, focusing on the preparation of silane precursors and the role of their 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 of the silane precursor and the preparation process ensured the structural stability of the mesoporous silica. Comparative Example 4 (preparation without silane precursor) lacked a functionalized silane network due to the simple mixing of TEOS, imidazoline silane, and 3-mercaptopropyltrimethoxysilane, resulting in decreased interfacial bonding between the modifier and the copper layer (SD = 0.30 μm, adhesion rate 89.5%). Comparative Example 5 (without 3-mercaptopropyltrimethoxysilane) lacked thiol functionalization, leading to reduced chemical activity of the silane precursor and affecting the chemical bonding between the modifier and the copper layer. Its performance was slightly better than Comparative Example 4 but still inferior (SD = 0.27 μm, copper oxide content 8.0 mol%).

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

[0086] The performance of Examples 11-14 and Comparative Examples 6-7 was tested according to the test method of Example 1 to examine the effect 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 exhibited excellent copper layer performance (SD ≤ 0.13 μm, adhesion ≥ 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. Comparative Example 6 (without surface modifier) ​​lacked surface functionalization, resulting in weakened interfacial bonding between mesoporous silica and WO3@ITO, leading to poor modifier dispersibility and a significant decrease in copper layer performance (SD = 0.32 μm, copper oxide content 10.5 mol%). Comparative Example 7 (using only vinyltrimethoxysilane) lacked amino functionalization, resulting in insufficient surface chemical activity; its performance was slightly better than Comparative Example 6 but still inferior (SD = 0.29 μm, copper oxide content 9.8 mol%).

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

[0092] Following the test method of Example 1, performance tests were conducted on Examples 15-20 and Comparative Examples 8-11 to examine the effects of tungstate and indium tin precursors. 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≤0.14μm, adhesion rate≥98.3%, copper oxide content≤2.3mol%), indicating that the optimized preparation process of tungstate and indium tin precursors ensured the stability of the WO3@ITO core-shell structure. Comparative Examples 8 (preparation without tungstate precursor) and 9 (preparation without cerium ammonium nitrate) showed poor performance (SD≥0.28μm, copper oxide content≥9.5mol%) due to the incomplete WO3 nanorod structure, resulting in decreased conductivity and oxidation resistance of the core-shell structure. Comparative Examples 10 (preparation without indium tin precursor) and 11 (preparation without dibutyltin dilaurate) showed the worst performance (SD≥0.30μm, copper oxide content≥10.3mol%) because the ITO layer was not effectively formed, leading to the loss of the synergistic effect of the core-shell structure.

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

[0097] Following the test method of Example 1, performance tests were conducted on Examples 1, 5, 10, and Comparative Examples 12-15 to examine the effects of thermal coating and interface 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 exhibit 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. Comparative Example 12 (lacking thermal coating) showed a significant performance decrease due to the loss of synergistic effect caused by the failure of WO3 and the indium tin precursor to form a core-shell structure (SD = 0.35 μm, copper oxide content 11.5 mol%). Comparative Example 13 (lacking the indium tin precursor) relied solely on WO3 nanorods, lacking the conductivity and protective effect of ITO, resulting in the worst performance (SD = 0.38 μm, copper oxide content 12.0 mol%). Comparative Examples 14 (lacking interfacial self-assembly) and 15 (lacking nitrogen-containing dispersant) showed poor performance due to the ineffective integration of modifier components, reduced dispersibility and interfacial bonding (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 subjected to durability tests under the following conditions: High-temperature and high-humidity cycling: After aging at 85°C and 85% relative humidity for 48 hours, they were placed at 25°C and 50% humidity for 2 hours, repeated 3 times. Mechanical damage: Ten metal needles with a diameter of 1 mm were used to prick the copper layer surface at a rate of 10 needles / dm. 2 Density puncture test. Acidic environment: Immersed in sulfuric acid solution at pH 4.0 for 48 hours, then placed in deionized water for 2 hours. After testing, uniformity, adhesion, and antioxidant properties were retested according to the method in 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 maintained excellent performance under high temperature and humidity, mechanical damage, and acidic environments (SD ≤ 0.16 μm, adhesion rate ≥ 97.3%, copper oxide content ≤ 2.6 mol%), indicating that the composite structure of the modifier has good durability and stability. Comparative Examples 12-13, lacking a core-shell structure, showed a significant decrease in performance under harsh conditions (SD ≥ 0.40 μm, copper oxide content ≥ 14.5 mol%), highlighting the importance of thermal coating and the indium tin precursor for durability. Comparative Examples 14-15, lacking interfacial self-assembly or dispersants, exhibited poor structural integration and durability (SD ≥ 0.30 μm, copper oxide content ≥ 10.8 mol%). The electroless copper plating nanomodifiers in Examples 1-20 significantly improved the uniformity (SD≤0.14μm), adhesion (≥98.0%), and antioxidant properties (copper oxide content≤2.3mol%) 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 omitting key components or process steps: the template agent and tapioca starch ensured the pore structure and photoresponsiveness of mesoporous silica. The silane precursor and its functionalized components enhanced interfacial bonding. The surface modifier improved the dispersibility and chemical activity of the modifier. The tungstate and indium tin precursor formed a stable WO3@ITO core-shell structure, enhancing conductivity and antioxidant properties. Thermal coating and interfacial self-assembly ensured the synergistic effect and stability of the composite structure. Furthermore, taking Example 8 as an example, ... Figure 2 , Figure 3 and Figure 4 As shown, the transmission electron microscope (TEM) images of the prepared mesoporous silica nanoparticles, the prepared WO3@ITO core-shell structure, and the prepared chemically plated copper nanomodifier indirectly demonstrate the success of the preparation.

[0106] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted herein.

Claims

1. A method for preparing a nano-modifier for electroless copper plating in SLP-type substrate aMSAP process, characterized in that: The process includes the following steps: (1) Functionalization of mesoporous silica carrier: The template agent, silane precursor and surface modifier are mixed in a mass ratio of 1:(0.5-2):(0.1-0.5), and a hydrolysis-condensation reaction is carried out under alkaline conditions to obtain mesoporous silica nanoparticles; (2) Construction of metal oxide core-shell structure: The tungstate precursor, ammonium sulfate and water are prepared into an aqueous solution in a mass ratio of (3-5):1:(15-20), and the pH is adjusted to 1.5-2.5 for hydrothermal treatment. The reaction generates WO3 nanorods, which are then thermally coated with indium tin precursor at a mass ratio of (10-20):1 to form a WO3@ITO core-shell structure; (3) Composite modifier assembly: The mesoporous silica nanoparticles obtained in step (1) are mixed with the WO3@ITO core-shell structure obtained in step (2) at a mass ratio of (1-3):1, and nitrogen-containing organic dispersant and boric acid buffer are added. The interface self-assembly is carried out under the action of ultrasonic field to obtain chemical copper plating nanomodifier.

2. The method for preparing the chemical copper plating nanomodifier for SLP-type substrate aMSAP process according to claim 1, characterized in that: The preparation method of the template agent mentioned in step (1) is as follows: Hexadecyltrimethylammonium bromide and polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer are mixed at a mass ratio of 1:(0.2-0.8). An aqueous solution containing 0.5-2 wt% sodium tartrate, at 10-20 times the mass of hexadecyltrimethylammonium bromide, is added. The mixture is ultrasonically dispersed at 50-70℃ for 40-60 min to form amphiphilic composite micelles. Then, cassava starch is added and mixed. The cassava starch and hexadecyltrimethylammonium bromide... The mass ratio of ammonium chloride to ammonium chloride is (0.2-0.6):

1. Then, a stepped temperature treatment is adopted: the first stage is 65-75℃ for 30-60 min, the second stage is rapid cooling to 0-5℃ for 10-15 min, and the third stage is heating to 40-50℃ at a rate of 2-5℃ / min. After the stepped temperature treatment, the sample is soaked in an ethanol solution containing 0.1-0.5 mol / L citric acid, and then UV curing is carried out under nitrogen protection to obtain a template agent with photoresponsive properties.

3. The method for preparing the chemical copper plating nanomodifier for SLP-type substrate aMSAP process according to claim 1, characterized in that: The preparation method of the silane precursor in step (1) is as follows: Tetraethoxysilane and triethoxy-3-(2-imidazolin-1-yl)propylsilane are mixed at a molar ratio of (5-8):

1. An ethanol solution containing 1-2 wt% 1,8-diazabicycloundec-7-ene is added at 5-10 times the mass of tetraethoxysilane. Hydrolysis is carried out under anaerobic conditions. Then, 3-mercaptopropyltrimethoxysilane is introduced into the product of the hydrolysis reaction, wherein the molar ratio between 3-mercaptopropyltrimethoxysilane and tetraethoxysilane is (0.3-0.6):

1. Microwave-assisted synthesis is used: power density: 50-100W / L, pressure control: 0.5-2MPa, reaction time: 10-30min. Finally, the product is soaked in an acetone solution containing 0.1-0.5 wt% benzotriazole, and then cross-linking is initiated under ultraviolet light.

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

5. The method for preparing the chemical copper plating nanomodifier for SLP-type substrate aMSAP process according to claim 1, characterized in that: The preparation method of the tungstate precursor in step (2) is as follows: Ammonium metatungstate and silicotungstic acid are mixed at a mass ratio of (3-5):

1. An ethylene glycol solution containing 0.1-0.5 mol / L ascorbic acid, at a mass ratio of 15-20 times that of ammonium metatungstate, is added. The reaction is carried out under microwave assistance, with a reaction power of 200-400 W, a reaction temperature of 80-120℃, and a reaction time of 10-30 min. Then, cerium ammonium nitrate, at a mass ratio of 0.2-0.6 times that of ammonium metatungstate, is added. The ultrasonic cavitation effect is used for treatment, wherein the frequency of the ultrasonic cavitation effect is 20-40kHz and the power density is 50-100W / L. Then, a staged hydrothermal crystallization process is adopted: the first stage: 100-120℃ for 4-6h, the second stage: rapidly heating to 180-200℃ and holding for 0.5-1h, the third stage: gradient cooling to 80-100℃ to obtain tungstate precursor; the parameters of the hydrothermal reaction in step (2) are as follows: 120-140℃, 6-10h.

6. The method for preparing the chemical copper plating nanomodifier for SLP-type substrate aMSAP process according to claim 1, characterized in that: The preparation method of the indium tin precursor in step (2) is as follows: Indium acetylacetone and dibutyltin dilaurate are mixed at a molar ratio of (3-5):2, and ethylene glycol solution containing 10-20wt% dodecyl mercaptan is added at 5-8 times the mass of indium acetylacetone. Then, microwave treatment is performed. The parameters of microwave treatment are as follows: power 300-500W, temperature 120-150℃, pressure 0.5-1.5MPa, to obtain the indium tin precursor.

7. The method for preparing the chemical copper plating nanomodifier for SLP-type substrate aMSAP process according to claim 1, characterized in that: The parameters for heat coating in step (2) are as follows: an asymmetric three-stage temperature control program is adopted. Nucleation stage: 120-150℃ for 0.5-1h, crystallization stage: 180-220℃ for 2-4h, pressure 0.5-1.5MPa, annealing stage: cooling to 80-100℃ at a rate of 5℃ / min.

8. The method for preparing the chemical copper plating nanomodifier for SLP-type substrate aMSAP process according to claim 1, characterized in that: The nitrogen-containing organic dispersant mentioned in step (3) is oleo-based aminoethyl imidazoline, and the final mass percentage of the nitrogen-containing organic dispersant is 5-10%; the boric acid buffer mentioned in step (3) is a 0.05-0.2M 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 10-20MHz, 30-45min.

9. A nano-modifier for electroless copper plating in the aMSAP process of SLP-type substrates, characterized in that, The SLP-type substrate aMSAP process chemical copper plating nanomodifier is obtained by the preparation method described in any one of claims 1-8.

Images