A high-reliability multilayer HDI substrate and its fabrication method

Abstract

This invention discloses a high-reliability multilayer HDI substrate and its preparation method, relating to the field of HDI substrate technology. The method includes the following steps: sequentially aligning and stacking a heat-resistant film, a transition film, and a copper foil, and then hot-pressing them to obtain a multilayer HDI substrate. This application utilizes the multilayer structure of the heat-resistant film, transition film, and copper foil to improve the adhesion to the copper foil while enhancing heat resistance, ensuring that the product is not affected by high temperature and humidity during long-term use, thus improving heat resistance and achieving high reliability.

Description

Technical Field

[0001] This invention relates to the field of HDI substrate technology, specifically a high-reliability multilayer HDI substrate and its preparation method. Background Technology

[0002] As the electronics and information industry continues to expand in fields such as 5G communication, artificial intelligence, and automobiles, it is gradually developing towards multi-functionality and high reliability. As the core support and interconnection carrier of electronic components, HDI substrate plays a crucial role in efficient signal transmission and stable component fixation, becoming an indispensable key component of electronic equipment.

[0003] Multilayer HDI substrates are high-density circuit boards formed by stacking layers using advanced hole-forming technologies such as micro-blind vias and buried vias to achieve micron-level precision interconnection. They are widely used in communication equipment, automotive electronics, aerospace and other fields.

[0004] Polyimide possesses excellent high-temperature resistance, mechanical properties, and insulation properties, making it widely used in multilayer HDI substrates. However, in practical applications, it has been gradually discovered that polyimide has a certain degree of hygroscopicity, which allows it to absorb moisture from the environment during long-term use. This leads to a decrease in its heat resistance under high temperature and humidity conditions. Furthermore, when moisture penetrates, it forms ion migration channels internally, easily inducing the conductive anode wire (CAF) phenomenon, resulting in circuit short-circuit failure. Simultaneously, the bonding strength between traditional polyimide and copper foil is limited, affecting reliability. These factors restrict the application and development of multilayer HDI substrates.

[0005] In summary, the development of a high-reliability multilayer HDI substrate and its fabrication method is of great significance in addressing the aforementioned issues. Summary of the Invention

[0006] The purpose of this invention is to provide a high-reliability multilayer HDI substrate and its preparation method to solve the problems mentioned in the background art.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for fabricating a high-reliability multilayer HDI substrate includes the following steps: The moisture-resistant film, transition film, and copper foil are aligned and stacked in sequence, and then hot-pressed to form a multilayer HDI substrate. The raw materials of the transition film include the following parts by weight: 19-20 parts of fluorinated naphthyldiamine monomer, 22-23 parts of bis(4-aminophenyl) phosphate, 21-23 parts of pyromellitic dianhydride, and 120-150 parts of dimethylacetamide. The raw materials of the heat-resistant film include the following parts by weight: 10-11 parts diamine-modified boron nitride, 10-12 parts bis(4-aminophenoxy)dimethylsilane, 39-41 parts fluorinated naphthyldiamine monomer, 38-39 parts 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride, and 120-150 parts dimethylacetamide.

[0008] Ideally, the thickness of the transition film is 5-15 μm; the thickness of the moisture-resistant film is 40-60 μm; and the thickness of the copper foil is 30-50 μm.

[0009] A more optimized method for preparing the transition film is as follows: S1-1: Under a nitrogen atmosphere, 2,6-dibromonaphthalene, 2-cyano-4-(trifluoromethyl)phenylboronic acid pinacol ester, tetrabutylammonium bromide, tetratriphenylphosphine palladium, and potassium carbonate were added to 1,4-dioxane and reacted at 75-85℃ for 30-40 h. Then, hydrazine hydrate and palladium on carbon catalyst were added and reacted at 75-85℃ for 30-40 min. After drying and purification, fluorinated naphthyldiamine monomer was obtained. S1-2: Under a nitrogen atmosphere, fluorinated naphthalene diamine monomer and bis(4-aminophenyl) phosphate are added to dimethylacetamide and stirred at 170~190 r / min for 1~3 h. Then, pyromellitic dianhydride is added and stirred at room temperature for 10~14 h. The mixture is dried at 85~95℃ for 30~40 min and then cured at 300~350℃ for 8~12 min to obtain a transition film.

[0010] In a more optimized manner, the raw material for the fluorinated naphthyldiamine monomer includes the following parts by weight: 2.5 to 3.2 parts of 2,6-dibromonaphthalene, 5 to 7 parts of pinacol ester of 2-cyano-4-(trifluoromethyl)phenylboronic acid, 0.8 to 1.2 parts of tetrabutylammonium bromide, 0.1 to 0.3 parts of tetratetraphenylphosphine palladium, 1 to 2 parts of potassium carbonate, 1 to 1.5 parts of hydrazine hydrate, and 0.2 to 0.5 parts of palladium on carbon catalyst.

[0011] A more optimized method for preparing the moisture-resistant heat-resistant film is as follows: S2-1: Add flake boron nitride and vinyl-terminated dimethylmethyl-3,3,3-trifluoro to an aqueous ethanol solution, react at 60-70°C for 3-5 h, purify and dry to obtain vinyl-modified boron nitride; S2-2: Under a nitrogen atmosphere, vinyl-modified boron nitride, 3-mercapto-1-propane and azobisisobutyronitrile were added to tetrahydrofuran and reacted at 60-70℃ for 5-7 h. After purification and drying, diamine-modified boron nitride was obtained. S2-3: Under a nitrogen atmosphere, diamine-modified boron nitride, bis(4-aminophenoxy)dimethylsilane, and fluorinated naphthyldiamine monomer are added to dimethylacetamide and stirred at 170~190 r / min for 1~3 h. Then, 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride is added and stirred at room temperature for 10~14 h. The mixture is then dried at 85~95℃ for 30~40 min and subsequently cured at 230~270℃ for 0.5~1 h to obtain a moisture-resistant heat-resistant film.

[0012] In a more optimized manner, the mass ratio of plate-shaped boron nitride to vinyl-terminated dimethylmethyl-3,3,3-trifluoro in the vinyl-modified boron nitride is 4:(0.05~0.1). The raw material for the diamine-modified boron nitride includes the following parts by weight: 5-6 parts vinyl-modified boron nitride, 2-3 parts 3-mercapto-1-propane, and 0.03-0.05 parts azobisisobutyronitrile.

[0013] Ideally, the sheet-like boron nitride is hexagonal boron nitride with a sheet diameter of 1~3μm and a thickness of 8~12nm.

[0014] In a more optimized manner, the hot pressing process involves a pressure of 1.2~1.5MPa, a temperature of 200~220℃, and a time of 1~3min.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are: This application constructs a multi-layer structure consisting of a heat-resistant film, a transition film, and a copper foil. This enhances the adhesion to the copper foil while simultaneously improving the heat resistance, ensuring that the product is not affected by high temperature and humidity during long-term use, thereby improving heat resistance and achieving high reliability.

[0016] The process involves using a small amount of fluorinated naphthyldiamine monomer, bis(4-aminophenyl) phosphate, and pyromellitic dianhydride as raw materials, which are then cured to form a transition film. Phosphate groups are introduced into the transition film to improve the interfacial bonding with the copper foil. Furthermore, compared to traditional thioether bonds and other groups, phosphate groups can synergistically work with fluorinated naphthyldiamine monomer to chelate copper ions migrating in the circuit, preventing the formation of conductive anode wires (CAF) and improving reliability. It is important to note that the amount of fluorinated naphthyldiamine monomer introduced into the transition film should not be too high. Excessive amounts will prevent the phosphate ester groups from bonding with the copper foil surface, resulting in uneven composition and reduced interfacial adhesion.

[0017] However, the phosphate groups in the transition film have a certain degree of hygroscopicity, and relying solely on the small amount of fluorinated naphthyldiamine monomer in the transition film is insufficient to maintain high temperature resistance and improve reliability under long-term high temperature and humidity conditions. Therefore, to address the aforementioned issues and ensure the product remains unaffected by high temperatures and humidity during long-term use, this application utilizes diamine-modified boron nitride, bis(4-aminophenoxy)dimethylsilane, fluorinated naphthyldiamine monomer, and 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride as raw materials to prepare a moisture-resistant film. In the moisture-resistant film, fluorinated naphthalene and siloxane form a highly hydrophobic and high-temperature resistant molecular backbone, while boron nitride nanosheets introduced through thiol clicks create a "maze effect," preventing the penetration of moisture and ions. Meanwhile, 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride provides flexible segments, achieving a balance between rigidity and flexibility and releasing internal stress. The synergistic effect of these components enhances the product's moisture resistance and reliability. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that the following quantities are by weight. There are no special restrictions on the manufacturers of the raw materials involved in this invention. Exemplary examples include: in the following embodiments, the sheet-like boron nitride has a sheet diameter of 2 μm and a thickness of 10 nm, purchased from Suzhou Napo Materials Technology Co., Ltd.; the CAS number of 2,6-dibromonaphthalene is 13720-06-4; the CAS number of 2-cyano-4-(trifluoromethyl)phenylboronic acid pinacol ester is 1073355-21-1; the CAS number of tetrakis(triphenylphosphine)palladium is 14221-01-3; bis(4-amino) The CAS number for phenyl phosphate is 407578-85-2; the CAS number for palladium on carbon catalyst is 53092-86-7; the CAS number for vinyl-terminated dimethylmethyl-3,3,3-trifluoro is 68951-98-4; the CAS number for 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride is 17828-53-4; the CAS number for dimethylacetamide is 127-19-5; the copper foil is a 35μm thick double-sided rolled copper foil, purchased from Shenzhen Yuandelai Industrial Materials Co., Ltd.; and all other raw materials are commercially available.

[0020] Example 1: A method for fabricating a high-reliability multilayer HDI substrate, comprising the following steps: A heat-resistant film (50μm), a transition film (10μm), and a copper foil (35μm) are aligned and stacked in sequence, and then hot-pressed (pressure 1.35MPa, temperature 210℃, time 2min) to obtain a multilayer HDI substrate. The preparation method of the transition film is as follows: S1-1: Under a nitrogen atmosphere, 2.86 parts of 2,6-dibromonaphthalene, 6 parts of 2-cyano-4-(trifluoromethyl)phenylboronic acid pinacol ester, 1 part of tetrabutylammonium bromide, 0.2 parts of tetratetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were added to 1,4-dioxane and reacted at 80°C for 36 h. Then, 1.2 parts of hydrazine hydrate and 0.32 parts of palladium on carbon catalyst were added, and the reaction was carried out at 80°C for 35 min. After drying and purification, fluorinated naphthyldiamine monomer was obtained. S1-2: Under a nitrogen atmosphere, 19.6 parts of fluorinated naphthyldiamine monomer and 22.5 parts of bis(4-aminophenyl) phosphate were added to 135 parts of dimethylacetamide and stirred at 180 r / min for 2 h. Then, 22 parts of pyromellitic dianhydride were added and stirred at room temperature for 12 h. The mixture was dried at 90 °C for 35 min and then cured at 325 °C for 10 min to obtain a transition film. The preparation method of the moisture-resistant heat-resistant film is as follows: S2-1: Plate-shaped boron nitride (hexagonal boron nitride, plate diameter 2μm, thickness 10nm) and vinyl-terminated dimethylmethyl-3,3,3-trifluoro were added to a 60wt% aqueous ethanol solution (the mass ratio of plate-shaped boron nitride to vinyl-terminated dimethylmethyl-3,3,3-trifluoro was 4:0.08), reacted at 65℃ for 4h, purified and dried to obtain vinyl-modified boron nitride; S2-2: Under a nitrogen atmosphere, 5.5 parts of vinyl-modified boron nitride, 2.5 parts of 3-mercapto-1-propane and 0.04 parts of azobisisobutyronitrile were added to tetrahydrofuran and reacted at 65°C for 6 h. After purification and drying, diamine-modified boron nitride was obtained. S2-3: Under a nitrogen atmosphere, 10.5 parts of diamine-modified boron nitride, 11 parts of bis(4-aminophenoxy)dimethylsilane, and 40 parts of fluorinated naphthyldiamine monomer were added to 135 parts of dimethylacetamide and stirred at 180 r / min for 2 h. Then, 38.5 parts of 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride were added and stirred at room temperature for 12 h. The mixture was then dried at 90 °C for 35 min and subsequently cured at 250 °C for 0.7 h to obtain a moisture-resistant heat-resistant film.

[0021] Example 2: A method for fabricating a high-reliability multilayer HDI substrate, comprising the following steps: A heat-resistant film (40μm), a transition film (5μm), and a copper foil (35μm) are aligned and stacked in sequence, and then hot-pressed (pressure 1.35MPa, temperature 210℃, time 2min) to obtain a multilayer HDI substrate. The preparation method of the transition film is as follows: S1-1: Under a nitrogen atmosphere, 2.86 parts of 2,6-dibromonaphthalene, 6 parts of 2-cyano-4-(trifluoromethyl)phenylboronic acid pinacol ester, 1 part of tetrabutylammonium bromide, 0.2 parts of tetratetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were added to 1,4-dioxane and reacted at 80°C for 36 h. Then, 1.2 parts of hydrazine hydrate and 0.32 parts of palladium on carbon catalyst were added, and the reaction was carried out at 80°C for 35 min. After drying and purification, fluorinated naphthyldiamine monomer was obtained. S1-2: Under a nitrogen atmosphere, 19 parts of fluorinated naphthyldiamine monomer and 22 parts of bis(4-aminophenyl) phosphate were added to 135 parts of dimethylacetamide and stirred at 180 r / min for 2 h. Then, 21 parts of pyromellitic dianhydride were added and stirred at room temperature for 12 h. The mixture was dried at 90 °C for 35 min and then cured at 325 °C for 10 min to obtain a transition film. The preparation method of the moisture-resistant heat-resistant film is as follows: S2-1: Plate-shaped boron nitride (hexagonal boron nitride, plate diameter 2μm, thickness 10nm) and vinyl-terminated dimethylmethyl-3,3,3-trifluoro were added to a 60wt% aqueous ethanol solution (the mass ratio of plate-shaped boron nitride to vinyl-terminated dimethylmethyl-3,3,3-trifluoro was 4:0.08), reacted at 65℃ for 4h, purified and dried to obtain vinyl-modified boron nitride; S2-2: Under a nitrogen atmosphere, 5.5 parts of vinyl-modified boron nitride, 2.5 parts of 3-mercapto-1-propane and 0.04 parts of azobisisobutyronitrile were added to tetrahydrofuran and reacted at 65°C for 6 h. After purification and drying, diamine-modified boron nitride was obtained. S2-3: Under a nitrogen atmosphere, 10 parts of diamine-modified boron nitride, 10 parts of bis(4-aminophenoxy)dimethylsilane, and 39 parts of fluorinated naphthyldiamine monomer were added to 135 parts of dimethylacetamide and stirred at 180 r / min for 2 h. Then, 38 parts of 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride were added and stirred at room temperature for 12 h. The mixture was then dried at 90 °C for 35 min and subsequently cured at 250 °C for 0.7 h to obtain a moisture-resistant heat-resistant film.

[0022] Example 3: A method for fabricating a high-reliability multilayer HDI substrate, comprising the following steps: A heat-resistant film (60μm), a transition film (15μm), and a copper foil (35μm) are aligned and stacked in sequence, and then hot-pressed (pressure 1.35MPa, temperature 210℃, time 2min) to obtain a multilayer HDI substrate. The preparation method of the transition film is as follows: S1-1: Under a nitrogen atmosphere, 2.86 parts of 2,6-dibromonaphthalene, 6 parts of 2-cyano-4-(trifluoromethyl)phenylboronic acid pinacol ester, 1 part of tetrabutylammonium bromide, 0.2 parts of tetratetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were added to 1,4-dioxane and reacted at 80°C for 36 h. Then, 1.2 parts of hydrazine hydrate and 0.32 parts of palladium on carbon catalyst were added, and the reaction was carried out at 80°C for 35 min. After drying and purification, fluorinated naphthyldiamine monomer was obtained. S1-2: Under a nitrogen atmosphere, 20 parts of fluorinated naphthyldiamine monomer and 23 parts of bis(4-aminophenyl) phosphate were added to 135 parts of dimethylacetamide and stirred at 180 r / min for 2 h. Then, 23 parts of pyromellitic dianhydride were added and stirred at room temperature for 12 h. The mixture was dried at 90 °C for 35 min and then cured at 325 °C for 10 min to obtain a transition film. The preparation method of the moisture-resistant heat-resistant film is as follows: S2-1: Plate-shaped boron nitride (hexagonal boron nitride, plate diameter 2μm, thickness 10nm) and vinyl-terminated dimethylmethyl-3,3,3-trifluoro were added to a 60wt% aqueous ethanol solution (the mass ratio of plate-shaped boron nitride to vinyl-terminated dimethylmethyl-3,3,3-trifluoro was 4:0.08), reacted at 65℃ for 4h, purified and dried to obtain vinyl-modified boron nitride; S2-2: Under a nitrogen atmosphere, 5.5 parts of vinyl-modified boron nitride, 2.5 parts of 3-mercapto-1-propane and 0.04 parts of azobisisobutyronitrile were added to tetrahydrofuran and reacted at 65°C for 6 h. After purification and drying, diamine-modified boron nitride was obtained. S2-3: Under a nitrogen atmosphere, 11 parts of diamine-modified boron nitride, 12 parts of bis(4-aminophenoxy)dimethylsilane, and 41 parts of fluorinated naphthyldiamine monomer were added to 135 parts of dimethylacetamide and stirred at 180 r / min for 2 h. Then, 39 parts of 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride were added and stirred at room temperature for 12 h. The mixture was dried at 90 °C for 35 min and then cured at 250 °C for 0.7 h to obtain a moisture-resistant heat-resistant film.

[0023] Comparative Example 1: In the transition film, bis(4-aminophenyl) phosphate was replaced with 4,4'-diaminodiphenyl sulfide; the rest was the same as in Example 1; the specific differences are as follows: The preparation method of the transition film is as follows: S1-1: Under a nitrogen atmosphere, 2.86 parts of 2,6-dibromonaphthalene, 6 parts of 2-cyano-4-(trifluoromethyl)phenylboronic acid pinacol ester, 1 part of tetrabutylammonium bromide, 0.2 parts of tetratetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were added to 1,4-dioxane and reacted at 80°C for 36 h. Then, 1.2 parts of hydrazine hydrate and 0.32 parts of palladium on carbon catalyst were added, and the reaction was carried out at 80°C for 35 min. After drying and purification, fluorinated naphthyldiamine monomer was obtained. S1-2: Under a nitrogen atmosphere, 19.6 parts of fluorinated naphthyldiamine monomer and 17.3 parts of 4,4'-diaminodiphenyl sulfide were added to 135 parts of dimethylacetamide and stirred at 180 r / min for 2 h. Then, 22 parts of pyromellitic dianhydride were added and stirred at room temperature for 12 h. The mixture was dried at 90 °C for 35 min and then cured at 325 °C for 10 min to obtain a transition film.

[0024] Comparative Example 2: In the transition film, the fluorinated naphthyldiamine monomer was in excess; the rest was the same as in Example 1; the specific differences are as follows: The preparation method of the transition film is as follows: S1-1: Under a nitrogen atmosphere, 2.86 parts of 2,6-dibromonaphthalene, 6 parts of 2-cyano-4-(trifluoromethyl)phenylboronic acid pinacol ester, 1 part of tetrabutylammonium bromide, 0.2 parts of tetratetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were added to 1,4-dioxane and reacted at 80°C for 36 h. Then, 1.2 parts of hydrazine hydrate and 0.32 parts of palladium on carbon catalyst were added, and the reaction was carried out at 80°C for 35 min. After drying and purification, fluorinated naphthyldiamine monomer was obtained. S1-2: Under a nitrogen atmosphere, 61.5 parts of fluorinated naphthyldiamine monomer and 11.2 parts of bis(4-aminophenyl) phosphate were added to 150 parts of dimethylacetamide and stirred at 180 r / min for 2 h. Then, 22 parts of pyromellitic dianhydride were added and stirred at room temperature for 12 h. The mixture was dried at 90 °C for 35 min and then cured at 325 °C for 10 min to obtain a transition film.

[0025] Comparative Example 3: Only a single transition film was used, without a heat-resistant film; the rest was the same as in Example 1; the specific differences are as follows: the transition film (10μm) and copper foil (35μm) were aligned and stacked in sequence, and hot-pressed (pressure of 1.35MPa, temperature of 210℃, time of 2min) to obtain a multilayer HDI substrate.

[0026] Comparative Example 4: Only a single moisture-resistant heat-resistant film was used, without a transition film; the rest was the same as in Example 1; the specific differences are as follows: the moisture-resistant heat-resistant film (50μm) and copper foil (35μm) were aligned and stacked in sequence, and hot-pressed (pressure of 1.35MPa, temperature of 210℃, time of 2min) to obtain a multilayer HDI substrate.

[0027] Comparative Example 5: The humid heat resistant film did not contain fluorinated naphthyldiamine monomer; all other aspects were the same as in Example 1; the specific differences are as follows: The preparation method of the moisture-resistant heat-resistant film is as follows: S2-1: Plate-shaped boron nitride (hexagonal boron nitride, plate diameter 2μm, thickness 10nm) and vinyl-terminated dimethylmethyl-3,3,3-trifluoro were added to a 60wt% aqueous ethanol solution (the mass ratio of plate-shaped boron nitride to vinyl-terminated dimethylmethyl-3,3,3-trifluoro was 4:0.08), reacted at 65℃ for 4h, purified and dried to obtain vinyl-modified boron nitride; S2-2: Under a nitrogen atmosphere, 5.5 parts of vinyl-modified boron nitride, 2.5 parts of 3-mercapto-1-propane and 0.04 parts of azobisisobutyronitrile were added to tetrahydrofuran and reacted at 65°C for 6 h. After purification and drying, diamine-modified boron nitride was obtained. S2-3: Under a nitrogen atmosphere, 10.5 parts of diamine-modified boron nitride and 22 parts of bis(4-aminophenoxy)dimethylsilane were added to 135 parts of dimethylacetamide and stirred at 180 r / min for 2 h. Then, 38.5 parts of 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride were added and stirred at room temperature for 12 h. The mixture was dried at 90 °C for 35 min and then cured at 250 °C for 0.7 h to obtain a moisture-resistant heat-resistant film.

[0028] Comparative Example 6: The heat-resistant film was produced without the addition of diamine-modified boron nitride; otherwise, it was the same as in Example 1; the specific differences are as follows: The preparation method of the moisture-resistant heat-resistant film is as follows: Under a nitrogen atmosphere, 11 parts of bis(4-aminophenoxy)dimethylsilane and 40 parts of fluorinated naphthyldiamine monomer were added to 135 parts of dimethylacetamide and stirred at 180 r / min for 2 h. Then, 30.7 parts of 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride were added and stirred at room temperature for 12 h. The mixture was then dried at 90 °C for 35 min and subsequently cured at 250 °C for 0.7 h to obtain a moisture-resistant heat-resistant film.

[0029] Performance Test 1: The multilayer HDI substrates prepared in Examples 1-3 and Comparative Examples 1-6 were placed in a constant temperature and humidity chamber at 85℃ / 85%RH for 600 hours, and their resistivity and glass transition temperature before and after were tested. The test results are shown in Table 1. Table 1

[0030] Conclusions: As shown in Table 1 above, the multilayer HDI substrate prepared in this application maintains good heat resistance and high reliability under high temperature and humidity conditions, as indicated by the data from Examples 1-3. Comparative Example 1 shows that in the transition film, the bis(4-aminophenyl) phosphate was replaced with 4,4'-diaminodiphenyl sulfide. The sulfide bond also provides some binding force, but the chelating effect of the phosphate group on copper ions is lost, resulting in a sharp decrease in CAF resistance and overall performance. Comparative Example 2 shows that in the transition film, the excessive amount of fluorinated naphthyl diamine monomer significantly reduces interfacial bonding and overall performance. Comparative Example 3 shows that only a single transition film was used. Without a moisture-resistant film, the phosphate ester groups in the single transition film have a certain degree of hygroscopicity. A small amount of fluorinated naphthyldiamine monomer alone cannot maintain long-term moisture-resistant performance. Therefore, with prolonged use, the moisture-resistant performance and overall performance significantly decrease. Data from Comparative Example 4 shows that with only a single moisture-resistant film and no transition film, the adhesion to the copper foil is poor, resulting in decreased performance. Data from Comparative Example 5 shows that without the addition of fluorinated naphthyldiamine monomer, the moisture-resistant film has increased hygroscopicity, decreased rigidity, and lacks synergistic properties with silane, leading to decreased overall performance. Data from Comparative Example 6 shows that without the addition of diamine-modified boron nitride, the moisture-resistant film lacks the labyrinth effect, resulting in decreased overall performance.

[0031] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for fabricating a high-reliability multilayer HDI substrate, characterized in that: Includes the following steps: The heat-resistant film, transition film, and copper foil are aligned and stacked in sequence, and then hot-pressed to form a multilayer HDI substrate. In the raw materials of the transition film, It includes the following parts by weight: 19-20 parts of fluorinated naphthyldiamine monomer, 22-23 parts of bis(4-aminophenyl) phosphate, 21-23 parts of pyromellitic dianhydride, and 120-150 parts of dimethylacetamide; The raw materials of the heat-resistant film include the following parts by weight: 10-11 parts diamine-modified boron nitride, 10-12 parts bis(4-aminophenoxy)dimethylsilane, 39-41 parts fluorinated naphthyldiamine monomer, 38-39 parts 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride, and 120-150 parts dimethylacetamide.

2. The method for preparing a high-reliability multilayer HDI substrate according to claim 1, characterized in that: The thickness of the transition film is 5~15μm; the thickness of the moisture-resistant film is 40~60μm; and the thickness of the copper foil is 30~50μm.

3. The method for preparing a high-reliability multilayer HDI substrate according to claim 2, characterized in that: The method for preparing the transition film is as follows: S1-1: Under a nitrogen atmosphere, 2,6-dibromonaphthalene, 2-cyano-4-(trifluoromethyl)phenylboronic acid pinacol ester, tetrabutylammonium bromide, tetratriphenylphosphine palladium, and potassium carbonate were added to 1,4-dioxane and reacted at 75-85℃ for 30-40 h. Then, hydrazine hydrate and palladium on carbon catalyst were added and reacted at 75-85℃ for 30-40 min. After drying and purification, fluorinated naphthyldiamine monomer was obtained. S1-2: Under a nitrogen atmosphere, fluorinated naphthalene diamine monomer and bis(4-aminophenyl) phosphate are added to dimethylacetamide and stirred at 170~190 r / min for 1~3 h. Then, pyromellitic dianhydride is added and stirred at room temperature for 10~14 h. The mixture is dried at 85~95℃ for 30~40 min and then cured at 300~350℃ for 8~12 min to obtain a transition film.

4. The method for preparing a high-reliability multilayer HDI substrate according to claim 3, characterized in that: In the raw materials of the fluorinated naphthyldiamine monomer, It comprises the following parts by weight: 2.5 to 3.2 parts of 2,6-dibromonaphthalene, 5 to 7 parts of pinacol ester of 2-cyano-4-(trifluoromethyl)phenylboronic acid, 0.8 to 1.2 parts of tetrabutylammonium bromide, 0.1 to 0.3 parts of tetra-triphenylphosphine palladium, 1 to 2 parts of potassium carbonate, 1 to 1.5 parts of hydrazine hydrate, and 0.2 to 0.5 parts of palladium on carbon catalyst.

5. The method for preparing a high-reliability multilayer HDI substrate according to claim 2, characterized in that: The method for preparing the heat-resistant film is as follows: S2-1: Add flake boron nitride and vinyl-terminated dimethylmethyl-3,3,3-trifluoro to an aqueous ethanol solution, react at 60-70°C for 3-5 h, purify and dry to obtain vinyl-modified boron nitride; S2-2: Under a nitrogen atmosphere, vinyl-modified boron nitride, 3-mercapto-1-propane and azobisisobutyronitrile were added to tetrahydrofuran and reacted at 60-70℃ for 5-7 h. After purification and drying, diamine-modified boron nitride was obtained. S2-3: Under a nitrogen atmosphere, diamine-modified boron nitride, bis(4-aminophenoxy)dimethylsilane, and fluorinated naphthyldiamine monomer are added to dimethylacetamide and stirred at 170~190 r / min for 1~3 h. Then, 3,3',4,4'-triphenyl diether tetracarboxylic dianhydride is added and stirred at room temperature for 10~14 h. The mixture is then dried at 85~95℃ for 30~40 min and subsequently cured at 230~270℃ for 0.5~1 h to obtain a moisture-resistant heat-resistant film.

6. The method for preparing a high-reliability multilayer HDI substrate according to claim 5, characterized in that: In the vinyl-modified boron nitride, the mass ratio of plate-like boron nitride to vinyl-terminated dimethylmethyl-3,3,3-trifluoro is 4:(0.05~0.1); The raw material for the diamine-modified boron nitride includes the following parts by weight: 5-6 parts vinyl-modified boron nitride, 2-3 parts 3-mercapto-1-propane, and 0.03-0.05 parts azobisisobutyronitrile.

7. The method for preparing a high-reliability multilayer HDI substrate according to claim 6, characterized in that: The plate-shaped boron nitride is hexagonal boron nitride with a plate diameter of 1~3μm and a thickness of 8~12nm.

8. The method for preparing a high-reliability multilayer HDI substrate according to claim 1, characterized in that: In the hot pressing process, the pressure is 1.2~1.5MPa, the temperature is 200~220℃, and the time is 1~3min.

9. A multilayer HDI substrate prepared by the method for preparing a high-reliability multilayer HDI substrate according to any one of claims 1 to 8.

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