Magnetron sputtering-based polyimide composite flexible film and preparation method thereof
By introducing modified diamine monomers and 4,4-diaminodiphenyl ether into the polyimide substrate and sputtering the metal layer with magnetron, the problems of poor flexibility and poor dielectric properties of aromatic polyimide materials are solved, and the high-performance preparation of polyimide composite flexible film is achieved, meeting the application needs of the microelectronics industry.
Patent Information
- Application Number
- CN202510046463.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-13
- Publication Date
- 2025-05-06
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Due to its strong inter-chain effect, poor flexibility, difficult to process, and poor dielectric performance, aromatic polyimide materials are difficult to meet the high demands of the microelectronics industry for moisture absorption and dielectric performance.
A polyimide substrate is prepared by mixing a flexible modified diamine monomer with 4,4-diaminodiphenyl ether and reacting with 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride at high temperature. A metal layer is plated on the polyimide substrate by magnetron sputtering to prepare a polyimide composite flexible film.
It improves the flexibility and processability of the polyimide substrate, reduces the hygroscopic rate and dielectric constant, improves the overall performance of the material, and meets the application needs of microelectronic devices.
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Figure SMS_1
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of polyimide flexible films, in particular to a polyimide composite flexible film based on magnetron sputtering and a preparation method thereof. Background Art
[0002] As a high-temperature resistant polymer material, polyimide is increasingly in demand in the aerospace, electrical and electronic, microelectronic equipment and other industries. Aromatic polyimide is widely used due to its excellent high and low temperature resistance, electrical properties, mechanical properties and stable chemistry. However, due to the strong interaction between the molecular chains of aromatic polyimide and the poor flexibility of the material, it is generally difficult to process and shape.
[0003] A layer of metal film is coated on the surface of the polyimide substrate by magnetron sputtering, so that the metal film layer is combined with the polyimide base film to obtain a polyimide composite film. Polyimide composite films based on magnetron sputtering are increasingly used in the microelectronics industry. With the development of the microelectronics industry, the requirements for the hygroscopicity and dielectric properties of polyimide are becoming higher and higher. Therefore, it is very necessary to modify the traditional aromatic polyimide. Summary of the invention
[0004] The object of the present invention is to provide a polyimide composite flexible film based on magnetron sputtering and a preparation method thereof, so as to solve the problems raised in the above background technology.
[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a polyimide composite flexible film based on magnetron sputtering and a preparation method thereof, comprising the following steps: Step 1: Add the mixed diamine material to N,N-dimethylacetamide under nitrogen environment, add 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride after stirring and dissolving at 25-35°C, stir and react for 1-2h, then coat the substrate on the surface of the carrier, heat under vacuum, cool naturally, boil in water to remove the film, soak in pretreatment liquid for pretreatment, and dry to obtain a polyimide flexible substrate; Step 2: A polyimide flexible substrate is placed on a substrate rack in a vacuum chamber, and a metal target is placed at the cathode position of a sputtering device; magnetron sputtering is performed in a vacuum environment to deposit a metal film; and annealing and polishing are performed to obtain a polyimide composite flexible film.
[0006] Furthermore, in step 1, the preparation method of the mixed diamine material comprises the following steps: S1: Disperse 4-fluoro-2-nitroaniline in dry tetrahydrofuran, use triethylamine as a salt-forming agent, stir evenly, add acryloyl chloride and a polymerization inhibitor, react at 0°C for 6-8h, then heat to 70°C and reflux for 6-8h, cool, filter, wash with ethyl acetate, and dry to obtain intermediate A; S2: Disperse intermediate A in tetrahydrofuran, add 1,1,3,3-tetramethyldisiloxane at 60-65°C under argon atmosphere with isopropanol solution of chloroplatinic acid as catalyst, and react for 8-12 hours to obtain intermediate B; S3: Disperse the intermediate B in anhydrous ethanol, add hydrazine hydrate with palladium carbon as a catalyst, heat to 80-85°C in an argon environment for 6-8h, cool, filter and collect the precipitate, dissolve and remove the palladium carbon in the precipitate with N,N-dimethylformamide, crystallize and purify at low temperature and dry to obtain a modified diamine monomer; S4: Mixing 4,4-diaminodiphenyl ether and modified diamine monomer to obtain a mixed diamine material.
[0007] Furthermore, in S1, the molar ratio of 4-fluoro-2-nitroaniline to acryloyl chloride is 1:1.
[0008] Further, in S2, the intermediate A reacts with 1,1,3,3-tetramethyldisiloxane at a molar ratio of carbon-carbon double bonds to silicon-hydrogen bonds of 1:1.
[0009] Further, in S4, 4,4-diaminodiphenyl ether and modified diamine monomer are mixed in a molar ratio of (4-9):1 to obtain a mixed diamine material.
[0010] Furthermore, in step 1, the heating step is: heating to 80-90°C at 0.5-0.6°C / min, heating to 200-220°C at 1-1.5°C / min, heating to 250°C at 0.8-1°C / min, and keeping warm for 2-3h.
[0011] Furthermore, in step 1, the pretreatment liquid is obtained by mixing anhydrous ethanol and anhydrous acetone in a volume ratio of 1:1.
[0012] Furthermore, in step 1, the mixed diamine material and 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride are reacted at a molar ratio of diamine to dianhydride of 1:1.
[0013] Furthermore, in step 2, the metal target material is any one of copper, silver, gold, aluminum, and titanium.
[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention provides a polyimide composite flexible film based on magnetron sputtering and a preparation process thereof. Traditional aromatic polyimide materials have the problems of strong molecular chain interaction, poor material flexibility, difficult processing, and poor dielectric properties. In the present invention, a flexible modified diamine monomer is mixed with 4,4-diaminodiphenyl ether, and reacted with 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride to prepare a polyimide substrate at high temperature. Among them, the preparation method of the modified diamine monomer is: first, using the reaction principle of acyl chloride and amine group, 4-fluoro-2-nitroaniline and acryloyl chloride are reacted in a molar ratio of 1:1 to obtain intermediate A; the unsaturated carbon-carbon double bond on intermediate A is subjected to a silylation reaction with the silicon-hydrogen bond on 1,1,3,3-tetramethyldisiloxane in a molar ratio of 1:1 to obtain intermediate B; finally, the nitro groups at both ends of intermediate B are reduced by hydrazine hydrate to obtain a modified diamine monomer. Among them, the Si-O-Si chain segment is introduced into the modified diamine monomer, which is beneficial to improve the flexibility of the polyimide substrate, thereby improving the processability of the polyimide substrate. The silicone and fluorine elements in the modified diamine have extremely strong hydrophobic properties, which effectively reduce the moisture absorption rate of the polyimide substrate; in addition, because the fluorine atom has strong electronegativity and a strong ability to adsorb electrons, it can reduce the polarizability of the material by limiting the polarization of dipoles or dipole molecules, so the modified diamine monomer reduces the dielectric constant of the polyimide substrate.
[0015] When preparing a polyimide substrate by mixing a modified diamine monomer with 4,4-diaminodiphenyl ether, the inventors found that the amount of modified diamine monomer used was not the more the better. Silicone improves the flexibility of the polyimide substrate, but at the same time the tensile strength of the substrate is also reduced. Although silicone has certain heat resistance, the heat resistance of the polyimide material itself is stronger than silicone. The addition of silicone will cause the heat resistance of the polyimide material to decrease, which will have an adverse effect. The present invention limits the mixing of 4,4-diaminodiphenyl ether and modified diamine monomer in a molar ratio of (4~9):1, and the obtained polyimide substrate has good properties. A composite flexible film is obtained by plating a metal layer on a polyimide substrate by magnetron sputtering, which meets the application in microelectronic devices. DETAILED DESCRIPTION
[0016] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.
[0017] Materials and sources used in the present invention: the polymerization inhibitor is polymerization inhibitor 701, and the metal target material is copper.
[0018] Embodiment 1: A polyimide composite flexible film based on magnetron sputtering and a preparation method thereof, comprising the following steps: Step 1: S1: Disperse 4-fluoro-2-nitroaniline in dry tetrahydrofuran, use triethylamine as a salt-forming agent, stir evenly, add acryloyl chloride and a polymerization inhibitor, react at 0°C for 6 hours, then heat to 70°C and reflux for 6 hours, cool down, filter, wash with ethyl acetate, and dry to obtain intermediate A; wherein the molar ratio of 4-fluoro-2-nitroaniline to acryloyl chloride is 1:1; S2: Disperse intermediate A in tetrahydrofuran, add 1,1,3,3-tetramethyldisiloxane at 60°C under argon atmosphere with an isopropanol solution of chloroplatinic acid as a catalyst, and react for 8 hours to obtain intermediate B; wherein intermediate A reacts with 1,1,3,3-tetramethyldisiloxane at a molar ratio of carbon-carbon double bonds to silicon-hydrogen bonds of 1:1; S3: Disperse the intermediate B in anhydrous ethanol, add hydrazine hydrate with palladium carbon as a catalyst, heat to 80°C in an argon environment for 6 hours, cool down, filter and collect the precipitate, dissolve and remove the palladium carbon in the precipitate with N,N-dimethylformamide, crystallize and purify at low temperature and dry to obtain a modified diamine monomer; S4: 4,4-diaminodiphenyl ether and modified diamine monomer are mixed at a molar ratio of 9:1 to obtain a mixed diamine material; the mixed diamine material is added to N,N-dimethylacetamide under a nitrogen environment, and 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride is added after stirring and dissolving at 25°C, and the mixture is stirred for reaction for 1 hour and then coated on the surface of the carrier, and heated under vacuum conditions; the heating steps are: heating to 80°C at 0.5°C / min, 200°C at 1°C / min, and 250°C at 1 / min, and naturally cooling after keeping the temperature for 2 hours, and then immersing in a pretreatment solution for pretreatment after de-molding by boiling in water, wherein the pretreatment solution is obtained by mixing anhydrous ethanol and anhydrous acetone at a volume ratio of 1:1, and drying to obtain a polyimide flexible substrate; wherein the mixed diamine material reacts with 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride at a molar ratio of diamine to dianhydride of 1:1; Step 2: A polyimide flexible substrate is placed on a substrate rack in a vacuum chamber, and a metal target is placed at the cathode position of a sputtering device; magnetron sputtering is performed in a vacuum environment to deposit a metal film; and annealing and polishing are performed to obtain a polyimide composite flexible film.
[0019] Embodiment 2: A polyimide composite flexible film based on magnetron sputtering and a preparation method thereof, comprising the following steps: Step 1: S1: Disperse 4-fluoro-2-nitroaniline in dry tetrahydrofuran, use triethylamine as a salt-forming agent, stir evenly, add acryloyl chloride and a polymerization inhibitor, react at 0°C for 7h, then heat to 70°C and reflux for 7h, cool, filter, wash with ethyl acetate, and dry to obtain intermediate A; wherein the molar ratio of 4-fluoro-2-nitroaniline to acryloyl chloride is 1:1; S2: Disperse intermediate A in tetrahydrofuran, add 1,1,3,3-tetramethyldisiloxane at 63°C under argon atmosphere with an isopropanol solution of chloroplatinic acid as a catalyst, and react for 10 hours to obtain intermediate B; wherein intermediate A reacts with 1,1,3,3-tetramethyldisiloxane at a molar ratio of carbon-carbon double bonds to silicon-hydrogen bonds of 1:1; S3: Disperse the intermediate B in anhydrous ethanol, add hydrazine hydrate with palladium carbon as a catalyst, heat to 82°C in an argon environment for 7 hours, cool down, filter and collect the precipitate, dissolve and remove the palladium carbon in the precipitate with N,N-dimethylformamide, crystallize and purify at low temperature and dry to obtain a modified diamine monomer; S4: 4,4-diaminodiphenyl ether and modified diamine monomer are mixed at a molar ratio of 7:1 to obtain a mixed diamine material; the mixed diamine material is added to N,N-dimethylacetamide under a nitrogen environment, and 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride is added after stirring and dissolving at 30°C, and the mixture is stirred for reaction for 1.5 hours and then coated on the surface of the carrier, and heated under vacuum conditions; the heating steps are: heating to 80°C at 0.5°C / min, 200°C at 1°C / min, and 250°C at 1 / min, and naturally cooling after keeping the temperature for 2 hours, and then immersing in a pretreatment solution for pretreatment after de-molding by boiling in water, wherein the pretreatment solution is obtained by mixing anhydrous ethanol and anhydrous acetone at a volume ratio of 1:1, and drying to obtain a polyimide flexible substrate; wherein the mixed diamine material reacts with 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride at a molar ratio of diamine to dianhydride of 1:1; Step 2: A polyimide flexible substrate is placed on a substrate rack in a vacuum chamber, and a metal target is placed at the cathode position of a sputtering device; magnetron sputtering is performed in a vacuum environment to deposit a metal film; and annealing and polishing are performed to obtain a polyimide composite flexible film.
[0020] Embodiment 3: A polyimide composite flexible film based on magnetron sputtering and a preparation method thereof, comprising the following steps: Step 1: S1: Disperse 4-fluoro-2-nitroaniline in dry tetrahydrofuran, use triethylamine as a salt-forming agent, stir evenly, add acryloyl chloride and a polymerization inhibitor, react at 0°C for 8h, then heat to 70°C and reflux for 8h, cool, filter, wash with ethyl acetate, and dry to obtain intermediate A; wherein the molar ratio of 4-fluoro-2-nitroaniline to acryloyl chloride is 1:1; S2: Disperse intermediate A in tetrahydrofuran, add 1,1,3,3-tetramethyldisiloxane at 65°C under argon atmosphere with an isopropanol solution of chloroplatinic acid as a catalyst, and react for 12 hours to obtain intermediate B; wherein intermediate A reacts with 1,1,3,3-tetramethyldisiloxane at a molar ratio of carbon-carbon double bonds to silicon-hydrogen bonds of 1:1; S3: Disperse the intermediate B in anhydrous ethanol, add hydrazine hydrate with palladium carbon as a catalyst, heat to 85°C in an argon environment for 8 hours, cool down, filter and collect the precipitate, dissolve and remove the palladium carbon in the precipitate with N,N-dimethylformamide, crystallize and purify at low temperature and dry to obtain a modified diamine monomer; S4: 4,4-diaminodiphenyl ether and modified diamine monomer are mixed in a molar ratio of 4:1 to obtain a mixed diamine material; the mixed diamine material is added to N,N-dimethylacetamide under a nitrogen environment, and 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride is added after stirring and dissolving at 35°C, and the mixture is stirred for reaction for 2 hours and then coated on the surface of the carrier, and heated under vacuum conditions; the heating steps are: heating to 80°C at 0.5°C / min, 200°C at 1°C / min, and 250°C at 1 / min, and naturally cooling after keeping the temperature for 2 hours, and then immersing in a pretreatment solution for pretreatment after de-molding by boiling in water, wherein the pretreatment solution is obtained by mixing anhydrous ethanol and anhydrous acetone in a volume ratio of 1:1, and drying to obtain a polyimide flexible substrate; wherein the mixed diamine material reacts with 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride in a molar ratio of diamine to dianhydride of 1:1; Step 2: A polyimide flexible substrate is placed on a substrate rack in a vacuum chamber, and a metal target is placed at the cathode position of a sputtering device; magnetron sputtering is performed in a vacuum environment to deposit a metal film; and annealing and polishing are performed to obtain a polyimide composite flexible film.
[0021] Comparative Example 1: No modified diamine monomer was added, and other parameters were the same as those in Example 1.
[0022] Step 1: Under a nitrogen environment, 4,4-diaminodiphenyl ether is added to N,N-dimethylacetamide, and 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride is added after stirring and dissolving at 25°C. After stirring and reacting for 1 hour, the mixture is coated on the surface of a slide and heated under vacuum conditions. The heating steps are as follows: heating to 80°C at 0.5°C / min, 200°C at 1°C / min, and 250°C at 1 / min, and naturally cooling after keeping the temperature for 2 hours. After de-molding by boiling in water, the mixture is immersed in a pretreatment solution for pretreatment, wherein the pretreatment solution is obtained by mixing anhydrous ethanol and anhydrous acetone in a volume ratio of 1:1, and drying to obtain a polyimide flexible substrate. In which, 4,4-diaminodiphenyl ether reacts with 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride in a molar ratio of 1:1. Step 2: A polyimide flexible substrate is placed on a substrate rack in a vacuum chamber, and a metal target is placed at the cathode position of a sputtering device; magnetron sputtering is performed in a vacuum environment to deposit a metal film; and annealing and polishing are performed to obtain a polyimide composite flexible film.
[0023] Comparative Example 2: The amount of the modified diamine monomer was increased, and the other parameters were the same as those in Example 2.
[0024] Step 1: S1: Disperse 4-fluoro-2-nitroaniline in dry tetrahydrofuran, use triethylamine as a salt-forming agent, stir evenly, add acryloyl chloride and a polymerization inhibitor, react at 0°C for 7h, then heat to 70°C and reflux for 7h, cool, filter, wash with ethyl acetate, and dry to obtain intermediate A; wherein the molar ratio of 4-fluoro-2-nitroaniline to acryloyl chloride is 1:1; S2: Disperse intermediate A in tetrahydrofuran, add 1,1,3,3-tetramethyldisiloxane at 63°C under argon atmosphere with an isopropanol solution of chloroplatinic acid as a catalyst, and react for 10 hours to obtain intermediate B; wherein intermediate A reacts with 1,1,3,3-tetramethyldisiloxane at a molar ratio of carbon-carbon double bonds to silicon-hydrogen bonds of 1:1; S3: Disperse the intermediate B in anhydrous ethanol, add hydrazine hydrate with palladium carbon as a catalyst, heat to 82°C in an argon environment for 7 hours, cool down, filter and collect the precipitate, dissolve and remove the palladium carbon in the precipitate with N,N-dimethylformamide, crystallize and purify at low temperature and dry to obtain a modified diamine monomer; S4: 4,4-diaminodiphenyl ether and modified diamine monomer are mixed in a molar ratio of 1:1 to obtain a mixed diamine material; the mixed diamine material is added to N,N-dimethylacetamide under a nitrogen environment, and 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride is added after stirring and dissolving at 30°C, and the mixture is stirred for reaction for 1.5 hours and then coated on the surface of the carrier, and heated under vacuum conditions; the heating steps are: heating to 80°C at 0.5°C / min, 200°C at 1°C / min, and 250°C at 1 / min, and naturally cooling after keeping the temperature for 2 hours, and then immersing in a pretreatment solution for pretreatment after de-molding by boiling in water, wherein the pretreatment solution is obtained by mixing anhydrous ethanol and anhydrous acetone in a volume ratio of 1:1, and drying to obtain a polyimide flexible substrate; wherein the mixed diamine material reacts with 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride in a molar ratio of diamine to dianhydride of 1:1; Step 2: A polyimide flexible substrate is placed on a substrate rack in a vacuum chamber, and a metal target is placed at the cathode position of a sputtering device; magnetron sputtering is performed in a vacuum environment to deposit a metal film; and annealing and polishing are performed to obtain a polyimide composite flexible film.
[0025] Comparative Example 3: p-nitroaniline was used instead of 4-fluoro-2-nitroaniline, and the other parameters were the same as those in Example 3.
[0026] Step 1: S1: dispersing p-nitroaniline in dry tetrahydrofuran, using triethylamine as a salt-forming agent, stirring evenly, adding acryloyl chloride and a polymerization inhibitor, reacting at 0°C for 8h, then heating to 70°C for reflux reaction for 8h, cooling, filtering, washing with ethyl acetate, and drying to obtain intermediate A; wherein the molar ratio of 4-fluoro-2-nitroaniline to acryloyl chloride is 1:1; S2: Disperse intermediate A in tetrahydrofuran, add 1,1,3,3-tetramethyldisiloxane at 65°C under argon atmosphere with an isopropanol solution of chloroplatinic acid as a catalyst, and react for 12 hours to obtain intermediate B; wherein intermediate A reacts with 1,1,3,3-tetramethyldisiloxane at a molar ratio of carbon-carbon double bonds to silicon-hydrogen bonds of 1:1; S3: Disperse the intermediate B in anhydrous ethanol, add hydrazine hydrate with palladium carbon as a catalyst, heat to 85°C in an argon environment for 8 hours, cool down, filter and collect the precipitate, dissolve and remove the palladium carbon in the precipitate with N,N-dimethylformamide, crystallize and purify at low temperature and dry to obtain a modified diamine monomer; S4: 4,4-diaminodiphenyl ether and modified diamine monomer are mixed in a molar ratio of 4:1 to obtain a mixed diamine material; the mixed diamine material is added to N,N-dimethylacetamide under a nitrogen environment, and 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride is added after stirring and dissolving at 35°C, and the mixture is stirred for reaction for 2 hours and then coated on the surface of the carrier, and heated under vacuum conditions; the heating steps are: heating to 80°C at 0.5°C / min, 200°C at 1°C / min, and 250°C at 1 / min, and naturally cooling after keeping the temperature for 2 hours, and then immersing in a pretreatment solution for pretreatment after de-molding by boiling in water, wherein the pretreatment solution is obtained by mixing anhydrous ethanol and anhydrous acetone in a volume ratio of 1:1, and drying to obtain a polyimide flexible substrate; wherein the mixed diamine material reacts with 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride in a molar ratio of diamine to dianhydride of 1:1; Step 2: A polyimide flexible substrate is placed on a substrate rack in a vacuum chamber, and a metal target is placed at the cathode position of a sputtering device; magnetron sputtering is performed in a vacuum environment to deposit a metal film; and annealing and polishing are performed to obtain a polyimide composite flexible film.
[0027] Experiment: The performance of the polyimide flexible substrates prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was tested.
[0028] Heat resistance test: Use a thermogravimetric analyzer with a heating rate of 20°C / min and nitrogen as the flowing medium. Record the temperature at which the thermal weight loss is 10%, which is recorded as Td 10% .
[0029] Hygroscopicity test: weigh the sample and record it as M 0 ; Soak the sample in distilled water at 25°C. After 48 hours, remove the residual distilled water on the surface of the film and weigh it, recorded as M 1 ; Calculate the moisture absorption rate according to the formula: Moisture absorption rate = (M 1 -M 0 ) / M 0 ×100%.
[0030] Mechanical properties test: The samples were tested using a universal testing machine with a sample size of 10 mm × 50 mm and a tensile rate of 10 mm / min. The samples were tested three times in parallel and the average value was taken.
[0031] Dielectric properties: The dielectric constant and dielectric loss of the film were tested using a broadband dielectric impedance spectrometer. The test temperature was 25°C and the test frequency range was 200~1MHz. Each sample was tested 3 times in parallel and the average value was taken.
[0032] The experimental results are shown in the following table.
[0033] Table 1. Test results of various properties of polyimide flexible substrate
[0034] Conclusion: The data of Examples 1 to 3 show that the polyimide flexible substrate prepared by the present invention has good performance and can be composited with metal to prepare a flexible film by magnetron sputtering. The data of Example 1 and Comparative Example 1 show that without adding modified diamine monomer, the moisture absorption rate of the substrate is high, the flexibility is poor, and the dielectric properties are poor. The data of Example 2 and Comparative Example 2 show that increasing the amount of modified diamine monomer will deteriorate the heat resistance and tensile strength of the substrate. The data of Example 3 and Comparative Example 3 show that the introduction of fluorine atoms is beneficial to reducing the moisture absorption rate and improving the dielectric properties.
[0035] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A method for preparing a polyimide composite flexible film based on magnetron sputtering, characterized in that: The following steps are involved: Step 1: Add the mixed diamine material to N,N-dimethylacetamide under nitrogen environment, add 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride after stirring and dissolving at 25-35°C, stir and react for 1-2h, then coat the substrate on the surface of the carrier, heat under vacuum, cool naturally, boil in water to remove the film, soak in pretreatment liquid for pretreatment, and dry to obtain a polyimide flexible substrate; Step 2: A polyimide flexible substrate is placed on a substrate rack in a vacuum chamber, and a metal target is placed at the cathode position of a sputtering device; magnetron sputtering is performed in a vacuum environment to deposit a metal film; and annealing and polishing are performed to obtain a polyimide composite flexible film.
2. The method for preparing a polyimide composite flexible film based on magnetron sputtering according to claim 1, characterized in that: In step 1, the preparation method of the mixed diamine material comprises the following steps: S1: Disperse 4-fluoro-2-nitroaniline in dry tetrahydrofuran, use triethylamine as a salt-forming agent, stir evenly, add acryloyl chloride and a polymerization inhibitor, react at 0°C for 6-8h, then heat to 70°C and reflux for 6-8h, cool, filter, wash with ethyl acetate, and dry to obtain intermediate A; S2: Disperse intermediate A in tetrahydrofuran, add 1,1,3,3-tetramethyldisiloxane at 60-65°C under argon atmosphere with isopropanol solution of chloroplatinic acid as catalyst, and react for 8-12 hours to obtain intermediate B; S3: Disperse the intermediate B in anhydrous ethanol, add hydrazine hydrate with palladium carbon as a catalyst, heat to 80-85°C in an argon environment for 6-8h, cool, filter and collect the precipitate, dissolve and remove the palladium carbon in the precipitate with N,N-dimethylformamide, crystallize and purify at low temperature and dry to obtain a modified diamine monomer; S4: Mixing 4,4-diaminodiphenyl ether and modified diamine monomer to obtain a mixed diamine material.
3. The method for preparing a polyimide composite flexible film based on magnetron sputtering according to claim 2, characterized in that: In S1, the molar ratio of 4-fluoro-2-nitroaniline to acryloyl chloride is 1:
1.
4. The method for preparing a polyimide composite flexible film based on magnetron sputtering according to claim 2, characterized in that: In S2, intermediate A reacts with 1,1,3,3-tetramethyldisiloxane at a molar ratio of carbon-carbon double bonds to silicon-hydrogen bonds of 1:
1.
5. The method for preparing a polyimide composite flexible film based on magnetron sputtering according to claim 2, characterized in that: In S4, 4,4-diaminodiphenyl ether and modified diamine monomer are mixed in a molar ratio of (4-9):1 to obtain a mixed diamine material.
6. The method for preparing a polyimide composite flexible film based on magnetron sputtering according to claim 1, characterized in that: In step 1, the heating steps are: heating to 80-90°C at 0.5-0.6°C / min, heating to 200-220°C at 1-1.5°C / min, heating to 250°C at 0.8-1°C / min, and keeping warm for 2-3h.
7. The method for preparing a polyimide composite flexible film based on magnetron sputtering according to claim 1, characterized in that: In step 1, the pretreatment liquid is obtained by mixing anhydrous ethanol and anhydrous acetone in a volume ratio of 1:
1.
8. The method for preparing a polyimide composite flexible film based on magnetron sputtering according to claim 1, characterized in that: In step 1, a mixed diamine material and 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride are reacted at a molar ratio of diamine to dianhydride of 1:
1.
9. The method for preparing a polyimide composite flexible film based on magnetron sputtering according to claim 1, characterized in that: In step 2, the metal target material is any one of copper, silver, gold, aluminum, and titanium. 10 . The polyimide composite flexible film prepared by the preparation method according to claim 1 .