High-voltage breakdown resistant high-insulation polymer film, method of manufacture and use

Abstract

The application discloses a high-pressure breakdown-resistant high-insulation polymer film, a preparation method and application thereof, and belongs to the technical field of preparation of electrically insulating polymer films. The application comprises the following steps: (1) preparing a high-insulation polymer solution; (2) preparing a solution of wide-bandgap nanoparticles with a certain concentration; (3) spin-coating the solution of wide-bandgap nanoparticles onto a base material to obtain a bottom layer of wide-bandgap inorganic layer; (4) spin-coating the high-insulation polymer solution in step (1) onto the wide-bandgap inorganic layer to obtain a middle layer of high-insulation polymer layer; and (5) continuously spin-coating the solution of wide-bandgap nanoparticles onto the high-insulation polymer layer, and obtaining the high-pressure breakdown-resistant high-insulation polymer film after ladder drying. The application spin-coats a layer of nanoparticles with a wide band gap on the upper and lower surfaces of the PEI film by using a spin-coating method, so that the Schottky emission at the electrode is inhibited, and the high-temperature electrically insulating performance of the PEI film is realized.

Description

Technical Field

[0001] This invention belongs to the field of electrical insulating polymer film preparation technology, specifically relating to a high-insulation polymer film resistant to high voltage breakdown, its preparation method, and its applications. Background Technology

[0002] Electrically insulating films are widely used in electronic devices due to their advantages such as low cost, ease of processing, and high voltage resistance. However, the miniaturization, integration, and high power consumption of electronic devices lead to significant heat accumulation, necessitating electrically insulating films with high temperature resistance and high breakdown capability. Compared to ceramic materials, polymer films exhibit excellent breakdown resistance. However, the intrinsic electrical insulation capability of polymer films is generally still limited, especially for polymer films with flexible molecular chains. When the ambient temperature exceeds their glass transition temperature (…),… When this occurs, the electrical insulation performance decreases significantly.

[0003] Currently, the main methods for preparing high-temperature resistant insulating polymer films include casting, coating, and casting. Polymer films prepared by these methods exhibit good density and high-temperature breakdown resistance, thus they are widely used in the field of electronic device insulation. To improve the electrical insulation properties of polymers, the primary method is to introduce wide-bandgap inorganic fillers or deep traps to effectively capture charges, followed by the preparation of high-insulation polymer films using methods such as casting, coating, and casting.

[0004] The main methods for preparing PEI films are blade coating and spin coating. For blade coating, a PEI solution of a certain concentration is prepared, filler is added to the PEI solution, and the solution is cast onto a substrate and then coated using a blade. Solvent evaporation treatment is then performed at 100 °C and 200 °C to obtain the film. Currently, the blade coating process can improve the electrical insulation properties of PEI films, mainly in terms of improved characteristic breakdown strength. Another method is spin coating of the solution under certain conditions. While this can produce polymer films with good density, their electrical insulation properties still need improvement. Furthermore, both methods only improve insulation performance by reducing bulk confinement conduction within the polymer film, often neglecting charge conduction at the metal electrode-dielectric interface. Summary of the Invention

[0005] To address the aforementioned shortcomings in the prior art, this invention provides a high-insulation polymer film resistant to high-voltage breakdown, its preparation method, and its applications. This invention uses a spin-coating method to spin-coat a layer of nanoparticles with a wide gap on the upper and lower surfaces of a PEI film, thereby suppressing Schottky emission at the electrodes and achieving high-temperature electrical insulation properties of the PEI film.

[0006] To achieve the above objectives, the technical solution adopted by the present invention to solve its technical problem is as follows: The purpose of this invention is to provide a method for preparing a high-insulation polymer film resistant to high-voltage breakdown, which includes the following steps: (1) Preparation of a highly insulating polymer solution; (2) Prepare a wide-bandgap nanoparticle solution with a concentration of 0.3~3.0 mg / mL, sonicate for 2~5 h, and then magnetically stir for 10~12 h; (3) Spin-coat the wide-bandgap nanoparticle solution onto the substrate material, dry to remove the solvent, and obtain the bottom wide-bandgap inorganic layer; (4) Spin-coat the high-insulation polymer solution from step (1) onto the wide-bandgap inorganic layer, dry to remove the solvent, and obtain the middle layer of high-insulation polymer layer; (5) Continue to spin-coat a wide-bandgap nanoparticle solution onto the high-insulation polymer layer, and obtain the high-insulation polymer film that is resistant to high voltage breakdown after step drying.

[0007] Furthermore, in step (1), the concentration of the high-insulation polymer solution is 0.15~0.25 g / mL.

[0008] Furthermore, in step (1), the concentration of the high-insulation polymer solution is 0.15~0.16 g / mL.

[0009] Furthermore, in step (1), the high insulating polymer is polyetherimide (PEI), polycarbonate, polyether ether ketone, polypropylene, or polyvinylidene fluoride, and the solvent used is NMP.

[0010] Furthermore, in step (2), the concentration of the wide-bandgap nanoparticle solution is 0.33~2.7 mg / mL, and the solvent used is NMP.

[0011] Furthermore, in step (2), the wide-bandgap nanoparticles are silicon dioxide, boron nitride nanosheets, carbon quantum dots (before and after fluorine atom doping or grafting with long-chain polar groups), or silicon carbide, etc., which are nanoparticles with wide bandgap.

[0012] Furthermore, in steps (3) and (4), the drying temperature is 80~95 ℃ and the drying time is 10~15 min.

[0013] Furthermore, in step (5), during the drying process, the temperature is first increased to 110~130 ℃ for 6~8 hours, and then further increased to 200~220 ℃ for 3~5 hours.

[0014] Another object of the present invention is to provide a highly insulating polymer film with high voltage breakdown resistance, which is prepared by the above method.

[0015] Another object of the present invention is to provide the use of the above-described high-insulation polymer film with high voltage breakdown resistance in the fabrication of electronic devices.

[0016] Furthermore, the electronic device is a polymer film capacitor used in high-temperature environments.

[0017] The beneficial effects of this invention are: This invention introduces a wide-bandgap insulating layer onto the surface of a polymer film using a spin-coating method, thereby achieving improved electrical insulation properties of the polymer film.

[0018] In the drying process of this invention, the excess solvent is first removed by drying at 110~130 ℃, and then the temperature is further increased to 200~220 ℃ for drying, thereby making the PEI composite film structure more compact and evaporating the residual solvent in the PEI composite film as much as possible. Attached Figure Description

[0019] Figure 1 The images show cross-sectional SEM images of PEI high-insulation polymer films; where (a) is PEI; (b) is B1; (c) is B2; (d) is B3; (e) is B4; and (f) is B5. Figure 2 AFM images of the surface of a PEI high-insulation polymer film; where (a) is PEI; (b) is B1; (c) is B2; (d) is B3; (e) is B4; and (f) is B5. Figure 3 Height analysis corresponding to surface AFM images of PEI high insulating polymer films; where (a) is PEI; (b) is B1; (c) is B2; (d) is B3; (e) is B4; and (f) is B5. Figure 4 Ultraviolet absorption spectra and band gap analysis of BNNDs; Figure 5 Ultraviolet absorption spectrum and band gap analysis of PEI high insulating polymer film; Figure 6 The breakdown performance of PEI high-insulation polymer film at different temperatures was analyzed; where (a) is 150 ℃; (b) is 200 ℃; and (c) is the characteristic breakdown strength at different temperatures. ); Figure 7 Leakage current density tests of PEI high insulating polymer films at different temperatures; where (a) is 150℃; (b) is 200℃; (c) is the fitted leakage current density at 150℃; and (d) is the fitted leakage current density at 200℃. Figure 8 The insulating conductivity of PEI high insulating polymer film at different temperatures. Detailed Implementation

[0020] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0021] Example 1 A high-insulation polymer film resistant to high-voltage breakdown is prepared by the following method: (1) Weigh 1 g of commercial PEI particles and put them into 6 mL of N-methylpyrrolidone (NMP) solvent. Stir at 50 °C for more than 12 h to obtain a uniform PEI solution.

[0022] (2) Prepare a low mass fraction wide-bandgap nanoparticle-boron nitride nanodots (BNNDs) NMP solution (0.002 g / 6 mL, named B1), sonicate for 2 h, and then magnetically stir for more than 12 h to obtain spin-coated upper and lower layer solutions.

[0023] (3) First, add 3 mL of wide-bandgap nanoparticle solution to a glass plate and spin-coat the solution at 300 rpm. Then, bake at 80 °C for 10 min to remove NMP and obtain the bottom wide-bandgap inorganic layer.

[0024] (4) Spin-coating the PEI layer. 6 mL of PEI solution was dropped onto the glass plate obtained in (3), and spin-coated at 300 rpm for 5 s and at 450 rpm for 10 s. After spin-coating, the plate was placed in a vacuum oven at 80 ℃ for 10 min to remove most of the NMP, and the lower wide-bandgap BNNDs layer and the middle PEI layer were obtained.

[0025] (5) Preparation of the upper wide-bandgap layer. 3 mL of wide-bandgap nanoparticle solution was dropped onto the glass plate obtained in (4), spin-coated at 300 rmp for 10 s, dried at 110 ℃ for 6 h, and finally dried at 200 ℃ for 3 h to obtain the PEI insulating film.

[0026] Example 2 A high-insulation polymer film resistant to high-voltage breakdown is prepared by the following method: (1) Weigh 1 g of commercial PEI particles and put them into 6 mL of N-methylpyrrolidone (NMP) solvent. Stir at 50 °C for more than 12 h to obtain a homogeneous PEI solution.

[0027] (2) Prepare a low mass fraction wide-bandgap nanoparticle-boron nitride nanodots (BNNDs) NMP solution (0.004 g / 6 mL, named B2), sonicate for 2 h, and then magnetically stir for more than 12 h to obtain spin-coated upper and lower layer solutions.

[0028] (3) First, add 3 mL of wide-bandgap nanoparticle solution to a glass plate and spin-coat the solution at 300 rpm. Then, bake at 80 °C for 10 min to remove NMP and obtain the bottom wide-bandgap inorganic layer.

[0029] (4) Spin-coating the PEI layer. 6 mL of PEI solution was dropped onto the glass plate obtained in (3), and spin-coated at 300 rpm for 5 s and at 450 rpm for 10 s. After spin-coating, the plate was placed in a vacuum oven at 80 ℃ for 10 min to remove most of the NMP, and the lower wide-bandgap BNNDs layer and the middle PEI layer were obtained.

[0030] (5) Preparation of the upper wide-bandgap layer. 3 mL of wide-bandgap nanoparticle solution was dropped onto the glass plate obtained in (4), spin-coated at 300 rmp for 10 s, dried at 110 ℃ for 6 h, and finally dried at 200 ℃ for 3 h to obtain the PEI insulating film.

[0031] Example 3 A high-insulation polymer film resistant to high-voltage breakdown is prepared by the following method: (1) Weigh 1 g of commercial PEI particles and put them into 6 mL of N-methylpyrrolidone (NMP) solvent. Stir at 50 °C for more than 12 h to obtain a homogeneous PEI solution.

[0032] (2) Prepare a low mass fraction wide-bandgap nanoparticle-boron nitride nanodots (BNNDs) NMP solution (0.008 g / 6 mL, named B3), sonicate for 2 h, and then magnetically stir for more than 12 h to obtain spin-coated upper and lower layer solutions.

[0033] (3) First, add 3 mL of wide-bandgap nanoparticle solution to a glass plate and spin-coat the solution at 300 rpm. Then, bake at 80 °C for 10 min to remove NMP and obtain the bottom wide-bandgap inorganic layer.

[0034] (4) Spin-coating the PEI layer. 6 mL of PEI solution was dropped onto the glass plate obtained in (3), and spin-coated at 300 rpm for 5 s and at 450 rpm for 10 s. After spin-coating, the plate was placed in a vacuum oven at 80 ℃ for 10 min to remove most of the NMP, and the lower wide-bandgap BNNDs layer and the middle PEI layer were obtained.

[0035] (5) Preparation of the upper wide-bandgap layer. 3 mL of wide-bandgap nanoparticle solution was dropped onto the glass plate obtained in (4), spin-coated at 300 rmp for 10 s, dried at 110 ℃ for 6 h, and finally dried at 200 ℃ for 3 h to obtain the PEI insulating film.

[0036] Example 4 A high-insulation polymer film resistant to high-voltage breakdown is prepared by the following method: (1) Weigh 1 g of commercial PEI particles and put them into 6 mL of N-methylpyrrolidone (NMP) solvent. Stir at 50 °C for more than 12 h to obtain a homogeneous PEI solution.

[0037] (2) Prepare a low mass fraction wide-bandgap nanoparticle-boron nitride nanodots (BNNDs) NMP solution (0.012 g / 6 mL, named B4), sonicate for 2 h, and then magnetically stir for more than 12 h to obtain spin-coated upper and lower layer solutions.

[0038] (3) First, add 3 mL of wide-bandgap nanoparticle solution to a glass plate and spin-coat the solution at 300 rpm. Then, bake at 80 °C for 10 min to remove NMP and obtain the bottom wide-bandgap inorganic layer.

[0039] (4) Spin-coating the PEI layer. 6 mL of PEI solution was dropped onto the glass plate obtained in (3), and spin-coated at 300 rpm for 5 s and at 450 rpm for 10 s. After spin-coating, the plate was placed in a vacuum oven at 80 ℃ for 10 min to remove most of the NMP, and the lower wide-bandgap BNNDs layer and the middle PEI layer were obtained.

[0040] (5) Preparation of the upper wide-bandgap layer. 3 mL of wide-bandgap nanoparticle solution was dropped onto the glass plate obtained in (4), spin-coated at 300 rmp for 10 s, dried at 110 ℃ for 6 h, and finally dried at 200 ℃ for 3 h to obtain the PEI insulating film.

[0041] Example 5 A high-insulation polymer film resistant to high-voltage breakdown is prepared by the following method: (1) Weigh 1 g of commercial PEI particles and put them into 6 mL of N-methylpyrrolidone (NMP) solvent. Stir at 50 °C for more than 12 h to obtain a homogeneous PEI solution.

[0042] (2) Prepare a low mass fraction wide-bandgap nanoparticle-boron nitride nanodots (BNNDs) NMP solution (0.016 g / 6 mL, named B5), sonicate for 2 h, and then magnetically stir for more than 12 h to obtain spin-coated upper and lower layer solutions.

[0043] (3) First, add 3 mL of wide-bandgap nanoparticle solution to a glass plate and spin-coat the solution at 300 rpm. Then, bake at 80 °C for 10 min to remove NMP and obtain the bottom wide-bandgap inorganic layer.

[0044] (4) Spin-coating the PEI layer. 6 mL of PEI solution was dropped onto the glass plate obtained in (3), and spin-coated at 300 rpm for 5 s and at 450 rpm for 10 s. After spin-coating, the plate was placed in a vacuum oven at 80 ℃ for 10 min to remove most of the NMP, and the lower wide-bandgap BNNDs layer and the middle PEI layer were obtained.

[0045] (5) Preparation of the upper wide-bandgap layer. 3 mL of wide-bandgap nanoparticle solution was dropped onto the glass plate obtained in (4), spin-coated at 300 rmp for 10 s, dried at 110 ℃ for 6 h, and finally dried at 200 ℃ for 3 h to obtain the PEI insulating film.

[0046] Comparative Example The specific process for spin-coating PEI thin films is as follows: 6 mL of PEI solution was dropped onto a glass plate, and then spin-coated at 300 rpm for 5 s and at 450 rpm for 10 s. After that, it was transferred to a vacuum oven at 80 ℃ and dried for 10 min. Then, the oven temperature was increased to 110 ℃ and dried for 6 h. Finally, it was dried at 200 ℃ for 3 h to obtain the PEI insulating film.

[0047] Test case This invention introduces a wide-bandgap insulating layer onto the surface of a polymer film using a spin-coating method, thereby achieving improved electrical insulation properties of the polymer film.

[0048] First, the density of the thin film is crucial to its breakdown performance. Characterization of the composite thin film cross-section using a JEOL JSM-7800F field emission scanning electron microscope (SEM) revealed that both the surface and cross-sectional SEM images of the prepared thin film exhibited a relatively dense and defect-free structure. Figure 1 (a~f), and the highly insulating polymer film maintains a relatively uniform thickness. This is beneficial for maintaining its high-temperature electrical insulation properties.

[0049] To further analyze whether BNNDs were successfully introduced onto the upper and lower surfaces of the PEI film, the surface morphology of the PEI composite film was observed using the tapping mode of a Bruker atomic force microscope (AFM). The film was fixed during the test to ensure that the surface morphology was clearly discernible. Figure 2 and Figure 3 Atomic force microscopy (AFM) images of the upper and lower surfaces of a high-insulation polymer film and the corresponding BNNDs dimensions are presented. It can be observed that BNNDs exist on the surface of all high-insulation polymer films. Figure 2 As the number of BNNDs increases, the number of BNNDs on the PEI film surface gradually increases, with the B3 film surface uniformly loaded with BNNDs. Figure 2 d and Figure 3 (d) This is beneficial for improving the high-temperature electrical insulation performance of PEI high-insulation polymer films. However, with the further increase of BNNDs, agglomeration occurs on the B5 film, resulting in more gaps between BNNDs, which is detrimental to its breakdown performance. All high-insulation polymer films maintain a low surface roughness (Rq = 0.38-1.39 nm), which helps reduce the concentration of local electric fields on the surface.

[0050] To further analyze the optical band gap of nanodots and composite films, ultraviolet-visible spectroscopy analysis was performed using a Shimadzu UV-2600 spectrophotometer. Visible BNNDs exhibited a relatively wide band gap ( Figure 4 After being loaded onto the PEI surface, the band gap of the high-insulation polymer film further increases. Figure 5 This is beneficial for capturing charges under high temperature and high electric field conditions. Therefore, highly insulating polymer films all exhibit increased high-temperature insulation properties. Figure 6 ).

[0051] The breakdown voltage of the PEI composite film was tested using an electrical breakdown tester (specifically, a BDJC-50 kV dielectric voltage tester manufactured by Beijing Precision Instrument Co., Ltd.). Before testing, a circular silver electrode with a diameter of 4 mm was deposited on the film surface. The voltage slope was set to 500 V / s, and the peak leakage current was 2 mA.

[0052] At room temperature, the characteristic breakdown strength ( The efficiency was increased from 454.6 MV / m to 756.7 MV / m for B3; at 150 ℃ The efficiency increased from 424.5 MV / m to 650.4 MV / m for B3; at 200 ℃ It increased from 364.0 MV / m to 529.7 MV / m for B3. Figure 6 c).

[0053] The leakage current density and insulation resistivity of the thin film at different temperatures are also important indicators for evaluating its insulation performance. The leakage current density was measured using the Trek 610E ferroelectric testing system (USA). Figure 7 Figures a and b show that the high-insulation polymer film exhibits a decrease in leakage current with increasing BNND concentration. For example, at 150 °C and 200 MV / m, the leakage current density decreases from 6.4 × 10⁻⁶ for the PEI film. 7 A / cm 2 It dropped to 2.0 × 10⁻⁶ for B3. 7 A / cm 2 At 200 ℃ and 200 MV / m, the leakage current density increased from 8.4 × 10⁻⁶ for the PEI film. 7 A / cm 2 It dropped to 3.3 × 10⁻⁶ for B3. 7 A / cm 2 .

[0054] also, Figure 7 c and d indicate that the highly insulating polymer film has an increased Schottky barrier height and a reduced jump distance at high temperatures, which means it can better capture moving charges under high temperature and high electric field conditions.

[0055] Meanwhile, the conductivity of the high-insulation polymer film was further characterized. The high-temperature conductivity of the PEI composite film was measured using an HGTZ-800 high-temperature four-probe tester from Beijing Huace Testing Instruments Co., Ltd. It can be seen that at 150℃ and 200 MV / m, the conductivity of the PEI film decreased from 3.2 × 10⁻⁶ m / s. -11 S / m decreased to 1.0 × 10⁻⁶ for B3. -11 S / m; at 200℃ and 200 MV / m, the conductivity of the PEI film increased from 4.2 × 10⁻⁶ S / m. -11 S / m decreased to 1.6 × 10⁻⁶ for B3. -11 S / m ( Figure 8 The above results all demonstrate that the insulation performance of the highly insulating polymer film prepared by this invention is significantly improved.

[0056] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a high-insulation polymer film resistant to high-voltage breakdown, characterized in that, Includes the following steps: (1) Preparation of a highly insulating polymer solution; (2) Prepare a wide-bandgap nanoparticle solution with a concentration of 0.3~3.0 mg / mL, sonicate for 2~5 h, and then stir magnetically for 10~12 h; (3) Spin-coat the wide-bandgap nanoparticle solution onto the substrate material, dry to remove the solvent, and obtain the bottom wide-bandgap inorganic layer; (4) Spin-coat the high-insulation polymer solution from step (1) onto the wide-bandgap inorganic layer, dry to remove the solvent, and obtain the middle layer of high-insulation polymer layer; (5) Continue to spin-coat a wide-bandgap nanoparticle solution onto the high-insulation polymer layer, and obtain the high-insulation polymer film that is resistant to high voltage breakdown after step drying.

2. The method for preparing a high-insulation polymer film resistant to high-voltage breakdown according to claim 1, characterized in that, In step (1), the concentration of the high-insulation polymer solution is 0.15~0.25 g / mL.

3. The method for preparing a high-insulation polymer film resistant to high-voltage breakdown according to claim 2, characterized in that, In step (1), the concentration of the high-insulation polymer solution is 0.15~0.16 g / mL.

4. The method for preparing a high-insulation polymer film resistant to high-voltage breakdown according to claim 1 or 2, characterized in that, In step (1), the high-insulation polymer is polyimide, polycarbonate, polyetheretherketone, polypropylene or polyvinylidene fluoride, and the solvent used is NMP.

5. The method for preparing a high-insulation polymer film resistant to high-voltage breakdown according to claim 1, characterized in that, In step (2), the concentration of the wide-bandgap nanoparticle solution is 0.33~2.7 mg / mL, and the solvent used is NMP.

6. The method for preparing a high-voltage-resistant, high-insulation polymer film according to claim 1 or 5, characterized in that, In step (2), the wide-bandgap nanoparticles are silicon dioxide, boron nitride nanosheets, carbon quantum dots (before and after fluorine atom doping or grafting with long-chain polar groups) or silicon carbide.

7. The method for preparing a high-insulation polymer film resistant to high-voltage breakdown according to claim 1, characterized in that, In steps (3) and (4), the drying temperature is 80~95 ℃ and the drying time is 10~15 min.

8. The method for preparing a high-insulation polymer film resistant to high-voltage breakdown according to claim 1, characterized in that, In step (5), when drying, first dry at 110~130 ℃ for 6~8 hours, and then continue to heat up to 200~220 ℃ for 3~5 hours.

9. A highly insulating polymer film with high voltage breakdown resistance, characterized in that, It is prepared by the method described in any one of claims 1 to 8.

10. The high-insulation polymer film with high voltage breakdown resistance as described in claim 9 for use in high-temperature environments.

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