A flexible high-barrier film for electronic packaging and preparation method thereof

Abstract

The present invention belongs to the technical field of electronic packaging materials. More specifically, it relates to a flexible high-barrier membrane for electronic packaging and a preparation method thereof. The specific preparation steps of the present invention include: substrate activation: activating the upper and lower surfaces of a polymer substrate to regulate the surface energy of the two surfaces to be ≥50mN / m respectively, to obtain an activated substrate; coating an organic buffer layer: coating the two surfaces of the activated substrate with a water-based organic coating, and then curing and molding to obtain an organic buffer layer with a moisture content of 15-20%, a thickness of 10-15μm, and a roughness Ra of 0.08-0.12μm; depositing an inorganic layer: pulsing a gaseous mixture of trimethylaluminum and ethyl orthosilicate on the surface of the organic buffer layer, followed by pulsing with water vapor, and cyclically pulsing to deposit an inorganic layer with a thickness of 15-20nm on the surface of the organic buffer layer; stacking and packaging: stacking the organic buffer layer and the inorganic layer for 8-10 cycles, then covering with UV curing glue, and annealing to obtain a flexible high-barrier membrane for electronic packaging.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic packaging materials, and more specifically relates to a flexible high-barrier film for electronic packaging and a preparation method thereof. Background Art

[0002] Flexible barrier films for electronic packaging are thin film materials that achieve high barrier properties (low oxygen and moisture permeability) through multi-layer lamination or specialized coating techniques, while maintaining excellent mechanical flexibility and lightweight characteristics. They are primarily used to protect electronic devices from environmental factors such as oxygen, moisture, and chemical corrosion. Their excellent flexibility also meets the application requirements of flexible electronic devices, and they are widely used in flexible displays, photovoltaic modules, wearable devices, medical electronics, and other fields.

[0003] However, existing flexible barrier films usually adopt a multi-layer alternating structure of "polymer substrate + inorganic barrier layer + organic buffer layer", which is prone to micro cracks when bent, mainly due to stress concentration. x ) has a high Young's modulus (high rigidity), while the polymer substrate has a low modulus (softness). When bent, the deformation capabilities of the two materials are mismatched, resulting in shear stress at the interface. When bending with a small radius (e.g., <5mm) or during dynamic bending (repeated folding), stress concentrates at defects in the inorganic layer (e.g., grain boundaries, areas of uneven coating), inducing microcracks. Once microcracks appear in the inorganic layer, they can propagate through the thickness and even penetrate the entire barrier layer, forming channels for water and oxygen permeation. In multilayer structures, if the organic buffer layer (e.g., acrylic resin) lacks elasticity and cannot effectively absorb stress, cracks can propagate across the layers.

[0004] Therefore, how to reduce the micro-crack problem of flexible barrier films during application is one of the challenges that those skilled in the art still need to face. Summary of the Invention

[0005] The technical problem addressed by this invention is that existing flexible barrier films used in electronic packaging, which employ a multi-layer alternating structure consisting of a polymer substrate, an inorganic barrier layer, and an organic buffer layer, are susceptible to microcracks when bent. To address this problem, the present invention provides a method for preparing a flexible high-barrier film for electronic packaging.

[0006] The object of the present invention is to provide a method for preparing a flexible high-barrier film for electronic packaging.

[0007] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0008] A method for preparing a flexible high-barrier film for electronic packaging, the specific preparation steps comprising:

[0009] Substrate activation:

[0010] Activating the upper and lower surfaces of the polymer substrate to adjust the surface energies of the two surfaces to be ≥50 mN / m, thereby obtaining an activated substrate;

[0011] Coating of organic buffer layer:

[0012] Applying a water-based organic coating on the two surfaces of the activated substrate, and then curing and forming the coating to obtain an organic buffer layer having a moisture content of 15-20%, a thickness of 10-15 μm, and a roughness Ra of 0.08-0.12 μm;

[0013] Deposition of inorganic layers:

[0014] At a temperature of 170° C., a gaseous mixture of trimethylaluminum and ethyl orthosilicate is pulsed onto the surface of the organic buffer layer, followed by a water vapor pulse, and this cycle is repeated to deposit an inorganic layer with a thickness of 15-20 nm on the surface of the organic buffer layer;

[0015] Stacking and packaging:

[0016] In this way, the organic buffer layer and the inorganic layer are stacked for 8-10 cycles, and then covered with UV curing glue and annealed to obtain a flexible high-barrier film for electronic packaging.

[0017] The beneficial effects of the above technical solution are:

[0018] The above technical solution first activates the substrate to enhance the interfacial adhesion between the substrate and the organic layer, thereby reducing the risk of delamination during the bending process. More importantly, in conventional existing technologies, the coating and deposition are started on one of the two surfaces of the substrate, while the above technical solution chooses to use the substrate as an intermediate layer and symmetrically deposit on its two surfaces. This is mainly because when a single-sided multilayer structure is bent, the center position is biased towards one side of the substrate, resulting in uneven tensile / compressive stress on the inorganic layer, which is prone to microcracks. In contrast, when stacked on both sides, the inorganic layers on both sides are subjected to symmetrical forces (when one side is compressed, the other side is stretched, and vice versa), and the stresses offset each other, which can alleviate the cracking problem during the bending process. At the same time, due to the difference in thermal expansion coefficients of each layer, the single-sided multilayer structure is prone to curling during annealing or temperature change. The double-sided symmetrical structure balances the contraction / expansion forces on both sides, significantly reducing curling.

[0019] In addition, the above technical solution promotes the hydrolysis reaction of trimethylaluminum and ethyl orthosilicate with the residual moisture in the organic buffer layer under high temperature conditions by mixing pulsed gaseous trimethylaluminum and ethyl orthosilicate in the organic buffer layer. The temperature of 170°C can not only reduce the residual carbon and form a denser Al-Si-O composite oxide layer, but also benefit from the volatilization of small molecular active water under high temperature conditions to form micropores. The presence of micropores can serve as one of the channels for stress release in the subsequent annealing process. At the same time, in the subsequent deposition process of the organic buffer layer, it can be partially embedded in the micropores, thereby forming a strong bond with the inorganic layer to prevent cracks.

[0020] Furthermore, the substrate activation further comprises:

[0021] The upper and lower surfaces of the polymer substrate are plasma activated by oxygen plasma at a power of 180-200 W and a treatment time of 80-110 s to adjust the surface energy of the two surfaces to be ≥50 mN / m, thereby obtaining an activated substrate.

[0022] Furthermore, the polymer substrate is selected from any one of polyethylene terephthalate (PET) or polyimide (PI);

[0023] Furthermore, the thickness of the polymer substrate is 25-50 μm.

[0024] Furthermore, the water-based organic coating is a water-based acrylic coating;

[0025] Furthermore, the water-based acrylic paint comprises: 60-65 parts of water-based acrylic emulsion, 15-20 parts of water, 3-5 parts of nano-silicon dioxide, 1-2 parts of silane coupling agent, 0.3-0.5 parts of leveling agent, and 0.1-0.3 parts of defoaming agent.

[0026] Further,

[0027] The water-based acrylic emulsion is selected from pure acrylic emulsion;

[0028] The D50 of the nano-silicon dioxide is 20-25 nm;

[0029] The silane coupling agent is selected from any one of silane coupling agent KH-540, silane coupling agent KH-550, silane coupling agent KH-560, silane coupling agent KH-570, and silane coupling agent KH-580;

[0030] The leveling agent is selected from BYK-346 (polyether modified siloxane);

[0031] The defoaming agent is selected from mineral oil TEGO Foamex 810.

[0032] Furthermore, the nano-silica is hollow nano-silica, and the particle size distribution of the nano-silica is 10-60 nm.

[0033] The beneficial effects of the above technical solution are:

[0034] By further adopting hollow nano-silica with a relatively narrow particle size distribution, on the one hand, the hollow structure can reduce the dielectric constant of the coating, reduce high-frequency signal transmission loss, and be suitable for 5G flexible electronic packaging; on the other hand, the hollow particles can be compressed to absorb stress when bent, reducing the expansion of cracks in the inorganic layer; more importantly, the monodisperse particles can easily self-assemble in the coating to form an ordered regular arrangement structure, thereby making the stress release of the coating more uniform and reducing the possibility of stress concentration.

[0035] Furthermore, the water-based acrylic paint further comprises a thermoplastic elastomer in an amount of 4-6% by mass of the water-based acrylic emulsion;

[0036] The thermoplastic elastomer is selected from linear SBS.

[0037] The beneficial effects of the above technical solution are:

[0038] By further adding thermoplastic elastomer, mainly because its elastic modulus is between that of acrylate and inorganic layer, it can gradiently transition stress and reduce the risk of interface peeling during bending; the styrene segment in SBS is compatible with acrylate, and the butadiene segment strengthens the chemical bond with the inorganic layer through free radical grafting reaction, thereby enhancing the interfacial bonding strength between the two, improving the interfacial compatibility, and further enhancing the product's anti-cracking ability.

[0039] Furthermore, in the trimethylaluminum and ethyl orthosilicate mixed gas, the mass ratio of trimethylaluminum to ethyl orthosilicate is 5.0-5.5:1.

[0040] Furthermore, the covering with UV curing glue includes: after covering the outermost layer with a thickness of 6-8 μm of UV glue, UV curing and packaging.

[0041] Furthermore, the annealing includes: annealing at a temperature of 90-110° C. for 1-2 hours. DETAILED DESCRIPTION

[0042] The present invention is further described below with reference to specific examples, which, however, are not intended to limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0043] Unless otherwise specified, the reagents and materials used in the following examples were commercially available.

[0044] Among them, hollow nano-silica is purchased from Qingdao Haowen New Material Technology Co., Ltd.

[0045] Example 1

[0046] Substrate activation:

[0047] Plasma activation was performed on the upper and lower surfaces of the polymer substrate using oxygen plasma at a power of 180 W and a treatment time of 80 seconds, so that the surface energy of both surfaces was controlled to be 50 mN / m, thereby obtaining an activated substrate. In this embodiment, plasma treatment was performed on one surface first, and then on the other surface.

[0048] The polymer substrate is selected from polyethylene terephthalate (PET);

[0049] Furthermore, the thickness of the polymer substrate is 25 μm;

[0050] Coating of organic buffer layer:

[0051] Applying a water-based organic coating on the two surfaces of the activated substrate, and then curing and forming the coating to obtain an organic buffer layer with a moisture content of 15%, a thickness of 10 μm, and a roughness Ra of 0.08 μm;

[0052] Specifically, the moisture content is controlled by adjusting the curing conditions during the curing process. The moisture content is detected by online monitoring using a halogen moisture meter (specific model: METTLER Toledo HC103).

[0053] In this embodiment, the specific curing conditions are: pre-drying at 80°C for 3 minutes, and then drying and curing at 120°C for 5 minutes;

[0054] In addition, the thickness and roughness of the organic buffer layer are regulated by controlling the coating conditions. Specifically, in this embodiment, slit coating is selected, the die gap is 15 μm, and the coating speed is 1.5 m / min.

[0055] During the coating process, the coating surface (5 × 5 mm area) was scanned by a white light interferometer (Zygo NewView) to confirm the film thickness after drying and curing. If the thickness was too large, the die gap could be reduced;

[0056] Detect Ra using online AFM (such as Bruker FastScan). If Ra is too large, reduce the coating speed.

[0057] The water-based organic coating is a water-based acrylic coating;

[0058] Furthermore, the water-based acrylic paint comprises: 60 parts of water-based acrylic emulsion, 15 parts of water, 3 parts of nano-silicon dioxide, 1 part of silane coupling agent, 0.3 parts of leveling agent, 0.1 parts of defoaming agent; and a thermoplastic elastomer in an amount of 4% by weight of the water-based acrylic emulsion;

[0059] The water-based acrylic emulsion is selected from pure acrylic emulsion;

[0060] The D50 of the nano-silicon dioxide is 20 nm;

[0061] The silane coupling agent is selected from silane coupling agent KH-540;

[0062] The leveling agent is selected from BYK-346 (polyether modified siloxane);

[0063] The defoaming agent is selected from mineral oil TEGO Foamex 810;

[0064] The thermoplastic elastomer is selected from linear SBS;

[0065] The nano-silica is hollow nano-silica, and the particle size distribution of the nano-silica is 10-60 nm;

[0066] Deposition of inorganic layers:

[0067] At a temperature of 170° C., a gaseous mixture of trimethylaluminum and ethyl orthosilicate was pulsed onto the surface of the organic buffer layer, followed by a water vapor pulse, and this pulse cycle was repeated to deposit a 15 nm thick inorganic layer on the surface of the organic buffer layer;

[0068] In the trimethylaluminum and ethyl orthosilicate mixed gas, the mass ratio of trimethylaluminum to ethyl orthosilicate is 5.0:1;

[0069] Stacking and packaging:

[0070] After 8 cycles of stacking the organic buffer layer and the inorganic layer, the outermost layer is covered with a 6μm thick UV adhesive, UV cured and encapsulated, and then annealed at 90°C for 1 hour to obtain a flexible high-barrier film for electronic packaging.

[0071] Among them, after 8 cycles of stacking, a corresponding multi-layer continuous stacking structure is formed on a single side of the substrate.

[0072] Example 2

[0073] Substrate activation:

[0074] Plasma activation was performed on the upper and lower surfaces of the polymer substrate using oxygen plasma at a power of 190 W and a treatment time of 100 s, so that the surface energy of both surfaces was controlled to be 62 mN / m, thereby obtaining an activated substrate. In this embodiment, plasma treatment was performed on one surface first, and then on the other surface.

[0075] The polymer substrate is selected from polyethylene terephthalate (PET);

[0076] Furthermore, the thickness of the polymer substrate is 25 μm;

[0077] Coating of organic buffer layer:

[0078] Applying a water-based organic coating on the two surfaces of the activated substrate, and then curing and forming the coating to obtain an organic buffer layer with a moisture content of 18%, a thickness of 12 μm, and a roughness Ra of 0.10 μm;

[0079] Specifically, the moisture content is controlled by adjusting the curing conditions during the curing process. The moisture content is detected by online monitoring using a halogen moisture meter (specific model: METTLER Toledo HC103).

[0080] In this embodiment, the specific curing conditions are: pre-drying at 80°C for 3 minutes, and then drying and curing at 115°C for 5 minutes;

[0081] In addition, the thickness and roughness of the organic buffer layer are regulated by controlling the coating conditions. Specifically, in this embodiment, slit coating is selected, the die gap is 17 μm, and the coating speed is 1.4 m / min.

[0082] During the coating process, the coating surface (5 × 5 mm area) was scanned by a white light interferometer (Zygo NewView) to confirm the film thickness after drying and curing. If the thickness was too large, the die gap could be reduced;

[0083] Detect Ra using online AFM (such as Bruker FastScan). If Ra is too large, reduce the coating speed.

[0084] The water-based organic coating is a water-based acrylic coating;

[0085] Furthermore, the water-based acrylic paint comprises: 62 parts of water-based acrylic emulsion, 18 parts of water, 4 parts of nano-silicon dioxide, 1.5 parts of silane coupling agent, 0.4 parts of leveling agent, 0.2 parts of defoaming agent; and a thermoplastic elastomer in an amount of 5% by weight of the water-based acrylic emulsion;

[0086] The water-based acrylic emulsion is selected from pure acrylic emulsion;

[0087] The D50 of the nano-silicon dioxide is 22 nm;

[0088] The silane coupling agent is selected from silane coupling agent KH-550;

[0089] The leveling agent is selected from BYK-346 (polyether modified siloxane);

[0090] The defoaming agent is selected from mineral oil TEGO Foamex 810;

[0091] The thermoplastic elastomer is selected from linear SBS;

[0092] The nano-silica is hollow nano-silica, and the particle size distribution of the nano-silica is 10-60 nm;

[0093] Deposition of inorganic layers:

[0094] At a temperature of 170° C., a gaseous mixture of trimethylaluminum and ethyl orthosilicate was pulsed onto the surface of the organic buffer layer, followed by a water vapor pulse, and this pulse cycle was repeated to deposit an 18 nm thick inorganic layer on the surface of the organic buffer layer.

[0095] In the trimethylaluminum and ethyl orthosilicate mixed gas, the mass ratio of trimethylaluminum to ethyl orthosilicate is 5.2:1;

[0096] Stacking and packaging:

[0097] After 9 cycles of stacking the organic buffer layer and the inorganic layer, the outermost layer was covered with a 7μm thick UV adhesive, UV cured and encapsulated, and then annealed at 100°C for 1.5 hours to obtain a flexible high-barrier film for electronic packaging.

[0098] Among them, after 9 cycles of stacking, a corresponding multi-layer continuous stacking structure is formed on a single side of the substrate.

[0099] Example 3

[0100] Substrate activation:

[0101] Plasma activation was performed on the upper and lower surfaces of the polymer substrate using oxygen plasma at a power of 200 W and a treatment time of 110 s, so that the surface energy of both surfaces was controlled to be 68 mN / m, thereby obtaining an activated substrate. In this embodiment, plasma treatment was performed on one surface first, and then on the other surface.

[0102] The polymer substrate is selected from polyethylene terephthalate (PET);

[0103] Furthermore, the thickness of the polymer substrate is 50 μm;

[0104] Coating of organic buffer layer:

[0105] Applying a water-based organic coating on the two surfaces of the activated substrate, and then curing and forming the coating to obtain an organic buffer layer with a moisture content of 20%, a thickness of 15 μm, and a roughness Ra of 0.12 μm;

[0106] Specifically, the moisture content is controlled by adjusting the curing conditions during the curing process. The moisture content is detected by online monitoring using a halogen moisture meter (specific model: METTLER Toledo HC103).

[0107] In this embodiment, the specific curing conditions are: pre-drying at 80°C for 3 minutes, and then drying and curing at 110°C for 5 minutes;

[0108] In addition, the thickness and roughness of the organic buffer layer are regulated by controlling the coating conditions. Specifically, in this embodiment, slit coating is selected, the die gap is 20 μm, and the coating speed is 1.3 m / min.

[0109] During the coating process, the coating surface (5 × 5 mm area) was scanned by a white light interferometer (Zygo NewView) to confirm the film thickness after drying and curing. If the thickness was too large, the die gap could be reduced;

[0110] Detect Ra using online AFM (such as Bruker FastScan). If Ra is too large, reduce the coating speed.

[0111] The water-based organic coating is a water-based acrylic coating;

[0112] Furthermore, the water-based acrylic paint comprises: 65 parts of water-based acrylic emulsion, 20 parts of water, 5 parts of nano-silicon dioxide, 2 parts of silane coupling agent, 0.5 parts of leveling agent, 0.3 parts of defoaming agent; and a thermoplastic elastomer in an amount of 6% by weight of the water-based acrylic emulsion;

[0113] The water-based acrylic emulsion is selected from pure acrylic emulsion;

[0114] The D50 of the nano-silicon dioxide is 25 nm;

[0115] The silane coupling agent is selected from silane coupling agent KH-560;

[0116] The leveling agent is selected from BYK-346 (polyether modified siloxane);

[0117] The defoaming agent is selected from mineral oil TEGO Foamex 810;

[0118] The thermoplastic elastomer is selected from linear SBS;

[0119] The nano-silica is hollow nano-silica, and the particle size distribution of the nano-silica is 10-60 nm;

[0120] Deposition of inorganic layers:

[0121] At a temperature of 170° C., a gaseous mixture of trimethylaluminum and ethyl orthosilicate was pulsed onto the surface of the organic buffer layer, followed by a water vapor pulse, and this pulse cycle was repeated to deposit a 20 nm thick inorganic layer on the surface of the organic buffer layer;

[0122] In the trimethylaluminum and ethyl orthosilicate mixed gas, the mass ratio of trimethylaluminum to ethyl orthosilicate is 5.5:1;

[0123] Stacking and packaging:

[0124] After 10 cycles of stacking the organic buffer layer and the inorganic layer, the outermost layer was covered with an 8μm thick UV adhesive, UV cured and encapsulated, and then annealed at 110°C for 2 hours to obtain a flexible high-barrier film for electronic packaging.

[0125] Among them, after 10 cycles of stacking, a corresponding multi-layer continuous stacking structure is formed on a single side of the substrate.

[0126] Example 4

[0127] Compared with Example 1, this embodiment differs in that the nano-silica is solid nano-silica, and the other conditions remain unchanged.

[0128] Example 5

[0129] The difference between this embodiment and embodiment 1 is that the particle size distribution range of the nano-silicon dioxide is 1-95 nm, and the other conditions remain unchanged.

[0130] Example 6

[0131] Compared with Example 1, this embodiment differs in that the mass ratio of trimethylaluminum to ethyl orthosilicate in the trimethylaluminum and ethyl orthosilicate mixed gas is 4:1, and other conditions remain unchanged.

[0132] Example 7

[0133] Compared with Example 1, this embodiment differs in that no thermoplastic elastomer is added, and other conditions remain unchanged.

[0134] Comparative Example 1

[0135] Compared with Example 1, this comparative example differs in that no ethyl orthosilicate is added, and other conditions remain unchanged.

[0136] Comparative Example 2

[0137] Compared with Example 1, this embodiment has the following differences:

[0138] Coating of organic buffer layer:

[0139] Applying a water-based organic coating on the two surfaces of the activated substrate, and then curing and forming the coating to obtain an organic buffer layer with a moisture content of 5%, a thickness of 10 μm, and a roughness Ra of 0.08 μm;

[0140] The rest of the conditions remain unchanged.

[0141] The performance tests of the products obtained in the examples and comparative examples were carried out, and the specific test methods and test results are as follows:

[0142] Under the conditions of an ambient temperature of 25°C and a relative humidity of 50%, a bending test was conducted using a Toyo Seiki bending tester. The bending radius was 3 mm, the bending frequency was 1 Hz, and the bending angle was 180°. The bending was performed 45,000 times. After the bending was completed, the surface cracks were observed using SEM and the maximum crack width was measured. The specific test results are shown in Table 1.

[0143] In addition, referring to ASTM F1249, the barrier properties (WVTR) of the corresponding products were tested before and after bending, and the change rate after bending compared to before bending was calculated. The detailed test results are shown in Table 1.

[0144] ;

[0145] As can be seen from the test results in Table 1, the product obtained by the present invention can improve the bending resistance of the product. Before and after bending, the cracks of the product are small and the change in barrier performance is relatively small.

[0146] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing a flexible high-barrier film for electronic packaging, characterized in that: The specific preparation steps include: Substrate activation: activating the upper and lower surfaces of the polymer substrate to adjust the surface energies of the two surfaces to be ≥50 mN / m, thereby obtaining an activated substrate; Coating of organic buffer layer: Applying a water-based organic coating on the two surfaces of the activated substrate, and then curing and forming the coating to obtain an organic buffer layer having a moisture content of 15-20%, a thickness of 10-15 μm, and a roughness Ra of 0.08-0.12 μm; The water-based organic coating is a water-based acrylic coating; Furthermore, the water-based acrylic paint comprises: 60-65 parts of water-based acrylic emulsion, 15-20 parts of water, 3-5 parts of nano-silicon dioxide, 1-2 parts of silane coupling agent, 0.3-0.5 parts of leveling agent, and 0.1-0.3 parts of defoaming agent; Furthermore, the water-based organic coating comprises a thermoplastic elastomer in an amount of 4-6% by mass of the water-based acrylic emulsion; The thermoplastic elastomer is selected from linear SBS; Deposition of inorganic layers: At a temperature of 170° C., a gaseous mixture of trimethylaluminum and ethyl orthosilicate is pulsed onto the surface of the organic buffer layer, followed by a water vapor pulse, and this cycle is repeated to deposit an inorganic layer with a thickness of 15-20 nm on the surface of the organic buffer layer; Stacking and packaging: In this way, the organic buffer layer and the inorganic layer are stacked for 8-10 cycles, and then covered with UV curing glue and annealed to obtain a flexible high-barrier film for electronic packaging.

2. The method for preparing a flexible high-barrier film for electronic packaging according to claim 1, characterized in that: The substrate activation further comprises: The upper and lower surfaces of the polymer substrate are plasma activated by oxygen plasma at a power of 180-200 W and a treatment time of 80-110 s to adjust the surface energy of the two surfaces to be ≥50 mN / m, thereby obtaining an activated substrate.

3. The method for preparing a flexible high-barrier film for electronic packaging according to any one of claims 1 or 2, characterized in that: The polymer substrate is selected from any one of polyethylene terephthalate (PET) or polyimide (PI); Furthermore, the thickness of the polymer substrate is 25-50 μm.

4. The method for preparing a flexible high-barrier film for electronic packaging according to claim 1, characterized in that: The water-based acrylic emulsion is selected from pure acrylic emulsion; The D50 of the nano-silicon dioxide is 20-25 nm; The silane coupling agent is selected from any one of silane coupling agent KH-540, silane coupling agent KH-550, silane coupling agent KH-560, silane coupling agent KH-570, and silane coupling agent KH-580; The leveling agent is selected from polyether modified siloxane with model number BYK-346; The defoaming agent is selected from mineral oil TEGO Foamex 810.

5. The method for preparing a flexible high-barrier film for electronic packaging according to claim 4, characterized in that: The nano-silica is hollow nano-silica, and the particle size distribution of the nano-silica is 10-60 nm.

6. The method for preparing a flexible high-barrier film for electronic packaging according to claim 1, characterized in that: In the trimethylaluminum and ethyl orthosilicate mixed gas, the mass ratio of trimethylaluminum to ethyl orthosilicate is 5.0-5.5:

1.

7. The method for preparing a flexible high-barrier film for electronic packaging according to claim 1, characterized in that: The covering with UV curing glue comprises: covering the outermost layer with UV glue having a thickness of 6-8 μm, and then UV curing and encapsulating.

8. The method for preparing a flexible high-barrier film for electronic packaging according to claim 1, characterized in that: The annealing comprises: annealing at a temperature of 90-110° C. for 1-2 hours.