Flexible high-barrier film for electronic packaging and preparation method thereof

Abstract

The invention belongs to the technical field of electronic packaging materials. The invention relates to the field of electronic packaging, in particular to a flexible high-barrier film for electronic packaging and a preparation method thereof. The preparation method comprises the following specific preparation steps: substrate activation: activating the upper surface and the lower surface of a polymer substrate to regulate the surface energy of the two surfaces to be greater than or equal to 50mN / m respectively, so as to obtain an activated substrate; coating an organic buffer layer: coating a water-based organic coating on the two surfaces of the activated substrate, and curing and forming to obtain the organic buffer layer with the water content of 15-20%, the thickness of 10-15 microns and the roughness Ra of 0.08-0.12 microns; depositing an inorganic layer: pulse gaseous trimethylaluminum and tetraethoxysilane mixed gas on the surface of the organic buffer layer, then pulse with water vapor, and circulating the pulse so as to deposit the inorganic layer with the thickness of 15-20nm on the surface of the organic buffer layer; and stacking and packaging: stacking the organic buffer layer and the inorganic layer for 8-10 cycles, then covering the organic buffer layer and the inorganic layer with a UV curing adhesive, and annealing to obtain the flexible high-barrier film for electronic packaging.

Description

Technical Field

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

[0002] The flexible barrier film for electronic packaging is a thin film material that achieves high barrier properties (low oxygen and moisture permeability) through multi-layer composite or special coating technology, while maintaining excellent mechanical flexibility and lightweight characteristics. It is mainly used to protect electronic devices from environmental factors such as oxygen, water vapor, and chemical corrosion. At the same time, its excellent flexibility can meet the application requirements of flexible electronic devices, and it is widely used in fields such as flexible displays, photovoltaic modules, wearable devices, and medical electronics.

[0003] However, the existing flexible barrier films usually adopt a multi-layer alternating structure of "polymer substrate + inorganic barrier layer + organic buffer layer". When bent, micro-cracks are likely to appear, and the main reason comes from stress concentration. The Young's modulus of the inorganic layer (such as SiO x )is high (rigid), while the modulus of the polymer substrate is low (soft). When bent, the deformation abilities of the two materials do not match, resulting in shear stress at the interface. When the bending radius is small (such as <5 mm) or dynamic bending (repeated folding) occurs, the stress concentrates at the defects of the inorganic layer (such as grain boundaries, coating uneven areas), triggering micro-cracks. Once micro-cracks appear in the inorganic layer, the cracks will expand along the thickness direction and even penetrate the entire barrier layer, forming a channel for water and oxygen penetration. In the multi-layer structure, if the elasticity of the organic buffer layer (such as acrylic resin) is insufficient and cannot effectively absorb stress, the cracks will propagate across 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 to be solved by the present invention is: for the existing flexible barrier film for electronic packaging that adopts a multi-layer alternating structure of "polymer substrate + inorganic barrier layer + organic buffer layer", it is prone to micro-cracks when bent. Based on the above problems, the present invention provides a preparation method for a flexible high-barrier film for electronic packaging.

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

[0007] The above object of the present invention is achieved by the following technical solutions: A preparation method for a flexible high-barrier film for electronic packaging, the specific preparation steps include: Substrate activation: The upper and lower surfaces of the polymer substrate are activated to regulate the surface energy of the two surfaces to be ≥50 mN / m respectively, obtaining an activated substrate; Coat an organic buffer layer: On the two surfaces of the activated substrate, a water-based organic coating is coated and then cured and formed to obtain an organic buffer layer with a moisture content of 15 - 20%, a thickness of 10 - 15 μm, and a roughness Ra of 0.08 - 0.12 μm; Deposit an inorganic layer: Under the condition of a temperature of 170 °C, a mixed gas of trimethylaluminum and tetraethyl orthosilicate in a pulsed gaseous state is applied to the surface of the organic buffer layer, and then water vapor is pulsed, and such cyclic pulsing is carried out to deposit an inorganic layer with a thickness of 15 - 20 nm on the surface of the organic buffer layer; Stack and encapsulate: In this way, the organic buffer layer - inorganic layer is stacked for 8 - 10 cycles, and then after covering with a UV - curable adhesive and annealing, a flexible high - barrier film for electronic packaging is obtained.

[0008] The beneficial effects of the above - mentioned technical solution are as follows: The above - mentioned technical solution first enhances the interfacial adhesion between the substrate and the organic layer by activating the substrate, thereby reducing the risk of delamination during the bending process; more importantly, in the conventional prior art, coating or deposition starts on one of the two surfaces of the substrate, while the above - mentioned technical solution selects the substrate as the intermediate layer and symmetrically deposits on its two surfaces respectively. This is mainly because, in the case of a single - side multi - layer structure, the center position biases towards the substrate side during bending, resulting in uneven tensile / compressive stress on the inorganic layer and prone to generating micro - cracks. On the contrary, when stacking on both sides, the stress on the two inorganic layers is symmetric (when one side is compressed, the other side is stretched, and vice versa), and the stresses cancel each other out, which can alleviate the cracking problem during the bending process; at the same time, due to the difference in the thermal expansion coefficients of each layer in the single - side multi - layer structure, it is prone to curling during annealing or temperature change, while the two - side symmetric structure has balanced shrinkage / expansion forces on both sides, significantly reducing curling; In addition, the above - mentioned technical solution promotes the hydrolysis reaction of trimethylaluminum and tetraethyl orthosilicate with the residual moisture in the organic buffer layer by applying a mixed pulsed gaseous state of trimethylaluminum and tetraethyl orthosilicate to the organic buffer layer under high - temperature conditions. The temperature of 170 °C can not only reduce the carbon residue and form a relatively dense Al - Si - O composite oxide layer, but also, due to the volatilization of small molecules and moisture to form micropores under high - temperature conditions, the presence of micropores can serve as one of the stress - release channels during the subsequent annealing process; at the same time, during the subsequent deposition process of the organic buffer layer, it can partially embed into the micropores, thereby forming a firm bond with the inorganic layer and preventing crack generation.

[0009] Further, the substrate activation further includes: Using oxygen plasma, the upper and lower surfaces of the polymer substrate are plasma-activated at a power of 180 - 200 W and a treatment time of 80 - 110 s to regulate the surface energy of the two surfaces to be ≥ 50 mN / m respectively, obtaining an activated substrate.

[0010] Furthermore, the polymer substrate is selected from any one of polyethylene terephthalate (PET) or polyimide (PI); And the thickness of the polymer substrate is 25 - 50 μm.

[0011] Furthermore, the waterborne organic coating is a waterborne acrylate coating; And the waterborne acrylate coating comprises: 60 - 65 parts of waterborne acrylate emulsion, 15 - 20 parts of water, 3 - 5 parts of nano-silica, 1 - 2 parts of silane coupling agent, 0.3 - 0.5 part of leveling agent, and 0.1 - 0.3 part of defoaming agent.

[0012] Furthermore, the waterborne acrylate emulsion is selected from pure acrylic emulsion; the D50 of the nano-silica 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 BYK-346 (polyether modified silicone); the defoaming agent is selected from mineral oil TEGO Foamex 810.

[0013] Furthermore, the nano-silica is hollow nano-silica, and the particle size distribution of the nano-silica is 10 - 60 nm.

[0014] The beneficial effects of the above technical solutions are: By further using 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 and reduce the high-frequency signal transmission loss, which is suitable for 5G flexible electronic packaging; on the other hand, the hollow particles can compress and absorb stress during bending, reducing the crack propagation of the inorganic layer; more importantly, the monodisperse particles are easy to self-assemble in the coating to form an ordered regular arrangement structure, so that the stress release of the coating is more uniform and the possibility of stress concentration is reduced.

[0015] Furthermore, the waterborne acrylate coating further comprises a thermoplastic elastomer accounting for 4 - 6% of the mass of the waterborne acrylate emulsion; The thermoplastic elastomer is selected from linear SBS.

[0016] The beneficial effects of the above technical solution are as follows: By further adding a thermoplastic elastomer, mainly because its elastic modulus is between that of the acrylate and the inorganic layer, it can gradually transition the stress and reduce the risk of interfacial peeling during bending; the styrene segment in SBS is compatible with the acrylate, and the butadiene segment enhances the chemical bonding with the inorganic layer through a free radical grafting reaction, thereby improving the interfacial bonding strength between the two, enhancing the interfacial compatibility, and further improving the anti-cracking ability of the product.

[0017] Furthermore, in the mixed gas of trimethylaluminum and tetraethyl orthosilicate, the mass ratio of trimethylaluminum to tetraethyl orthosilicate is 5.0 - 5.5:1.

[0018] Furthermore, the covering UV curable adhesive includes: after covering a UV adhesive with a thickness of 6 - 8 μm on the outermost layer, performing UV curing encapsulation.

[0019] Furthermore, the annealing includes: performing annealing treatment for 1 - 2 h at a temperature of 90 - 110°C. Specific embodiments

[0020] The following specific embodiments are used to further illustrate the present invention, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the technical field.

[0021] Unless otherwise specified, the reagents and materials used in the following embodiments are all commercially available.

[0022] Among them, hollow nano-silica is purchased from Qingdao Haoen New Material Technology Co., Ltd.

[0023] Example 1 Substrate activation: Using oxygen plasma, at a power of 180 W and a treatment time of 80 s, perform plasma activation on the upper and lower surfaces of the polymer substrate to adjust the surface energy of the two surfaces to 50 mN / m, obtaining an activated substrate; in this embodiment, first perform plasma treatment on one surface, and after completion, perform plasma treatment on the other surface; The polymer substrate is selected from polyethylene terephthalate (PET); And, the thickness of the polymer substrate is 25 μm; Coating an organic buffer layer: On the two surfaces of the activated substrate, coat a water-based organic coating, and then cure and form it to obtain an organic buffer layer with a water content of 15%, a thickness of 10 μm, and a roughness Ra of 0.08 μm; Specifically, during the curing and forming process, the moisture content is regulated by the curing conditions, and the moisture content is detected by online monitoring using a halogen moisture meter (specific model: METTLER Toledo HC103). In this embodiment, the specific curing conditions are: pre-drying at 80°C for 3 minutes first, and then drying and curing at 120°C for 5 minutes. In addition, the thickness and roughness of the organic buffer layer are regulated by controlling the coating conditions. Specifically, in this embodiment, slot coating is selected, the die gap is 15 μm, and the coating speed is 1.5 m / min. During the coating process, the surface of the coating (5×5 mm area) is scanned by a white light interferometer (Zygo NewView) to confirm the film thickness after drying and curing. If the thickness is too large, the die gap can be reduced. Ra is detected by online AFM (such as Bruker FastScan). If Ra is too large, the coating speed is reduced. The water-based organic coating is a water-based acrylate coating. Moreover, the water-based acrylate coating includes: 60 parts of water-based acrylate emulsion, 15 parts of water, 3 parts of nano-silica, 1 part of silane coupling agent, 0.3 part of leveling agent, 0.1 part of defoaming agent; and 4% of the mass of the water-based acrylate emulsion of thermoplastic elastomer. The water-based acrylate emulsion is selected from pure acrylic emulsions. The D50 of the nano-silica is 20 nm. The silane coupling agent is selected from silane coupling agent KH-540. The leveling agent is selected from BYK-346 (polyether modified silicone). The defoaming agent is selected from mineral oil TEGO Foamex 810. The thermoplastic elastomer is selected from linear SBS. The nano-silica is hollow nano-silica, and moreover, the particle size distribution of the nano-silica is 10 - 60 nm. Depositing an inorganic layer: At a temperature of 170°C, a mixed gas of trimethylaluminum and tetraethyl orthosilicate in a pulsed gaseous state is applied to the surface of the organic buffer layer, and then water vapor is pulsed. Such cyclic pulsing is performed to deposit an inorganic layer with a thickness of 15 nm on the surface of the organic buffer layer. In the mixed gas of trimethylaluminum and tetraethyl orthosilicate, the mass ratio of trimethylaluminum to tetraethyl orthosilicate is 5.0:1. Stacking and encapsulating: After such 8 cycles of organic buffer layer - inorganic layer stacking, after covering the outermost layer with a UV glue with a thickness of 6 μm, UV curing and encapsulation are carried out, and then annealing treatment is carried out at a temperature of 90 °C for 1 h to obtain a flexible high - barrier film for electronic packaging; Among them, after 8 cycles of stacking, a corresponding multi - layer continuous stacking structure is formed on one side of the substrate.

[0024] Example 2 Substrate activation: Using oxygen plasma, under the conditions of a power of 190 W and a treatment time of 100 s, the upper and lower surfaces of the polymer substrate are subjected to plasma activation to regulate the surface energy of the two surfaces to 62 mN / m to obtain an activated substrate; in this example, one surface is first subjected to plasma treatment, and after completion, the other surface is subjected to plasma treatment; The polymer substrate is selected from polyethylene terephthalate (PET); And, the thickness of the polymer substrate is 25 μm; Coating the organic buffer layer: On the two surfaces of the activated substrate, a water - based organic coating is coated and then cured and formed 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; Specifically, during the curing and forming process, the moisture content is regulated by the curing conditions, and the moisture content is detected by online monitoring using a halogen moisture meter (specific model: METTLER Toledo HC103); In this example, the specific curing conditions are: pre - drying at 80 °C for 3 min first, and then drying and curing at 115 °C for 5 min; In addition, the thickness and roughness of the organic buffer layer are regulated by controlling the coating conditions. Specifically, in this example, slot coating is selected, the die head gap is 17 μm, and the coating speed is 1.4 m / min; During the coating process, the surface of the coating (5×5 mm area) is scanned by a white - light interferometer (Zygo NewView) to confirm the film thickness after drying and curing. If the thickness is too large, the die head gap can be reduced; The Ra is detected by online AFM (such as Bruker FastScan). If the Ra is too large, the coating speed is reduced; The water - based organic coating is a water - based acrylate coating; And, the water - based acrylate coating includes: 62 parts of water - based acrylate emulsion, 18 parts of water, 4 parts of nano - silica, 1.5 parts of silane coupling agent, 0.4 part of leveling agent, 0.2 part of defoaming agent; and 5% of the mass of the water - based acrylate emulsion of thermoplastic elastomer; The aqueous acrylate emulsion is selected from pure acrylic emulsions; The D50 of the nano-silica is 22 nm; The silane coupling agent is selected from silane coupling agent KH-550; The leveling agent is selected from BYK-346 (polyether modified silicone); The defoaming agent is selected from mineral oil TEGO Foamex 810; The thermoplastic elastomer is selected from linear SBS; The nano-silica is hollow nano-silica, and the particle size distribution of the nano-silica is 10 - 60 nm; Depositing an inorganic layer: At a temperature of 170 °C, a mixed gas of trimethylaluminum and tetraethyl orthosilicate in a pulsed gaseous state is applied to the surface of the organic buffer layer, and then water vapor is pulsed. Such pulsed cycles are carried out to deposit an inorganic layer with a thickness of 18 nm on the surface of the organic buffer layer; In the mixed gas of trimethylaluminum and tetraethyl orthosilicate, the mass ratio of trimethylaluminum to tetraethyl orthosilicate is 5.2:1; Stacking and encapsulating: After stacking the organic buffer layer - inorganic layer for 9 cycles, after covering a 7-μm-thick UV glue on the outermost layer, UV curing and encapsulation are carried out, and then annealing treatment is carried out at a temperature of 100 °C for 1.5 h to obtain a flexible high-barrier film for electronic packaging; Among them, after stacking 9 cycles, a corresponding multi-layer continuous stacked structure is formed on one side of the substrate.

[0025] Example 3 Substrate activation: Using oxygen plasma, at a power of 200 W and a treatment time of 110 s, the upper and lower surfaces of the polymer substrate are subjected to plasma activation to adjust the surface energy of the two surfaces to 68 mN / m to obtain an activated substrate; in this example, plasma treatment is first carried out on one surface, and after completion, plasma treatment is carried out on the other surface; The polymer substrate is selected from polyethylene terephthalate (PET); And the thickness of the polymer substrate is 50 μm; Coating an organic buffer layer: On the two surfaces of the activated substrate, an aqueous organic coating is applied and then cured and formed 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; Specifically, during the curing and forming process, the moisture content is regulated by the curing conditions, and the moisture content is detected by online monitoring using a halogen moisture analyzer (specific model: METTLER Toledo HC103). In this embodiment, the specific curing conditions are as follows: pre-dry at 80°C for 3 minutes, and then dry and cure at 110°C for 5 minutes. In addition, the thickness and roughness of the organic buffer layer are regulated by controlling the coating conditions. Specifically, in this embodiment, slot coating is selected, the die gap is 20 μm, and the coating speed is 1.3 m / min. During the coating process, the surface of the coating (5×5 mm area) is scanned by a white light interferometer (Zygo NewView) to confirm the thickness of the film after drying and curing. If the thickness is too large, the die gap can be reduced. The Ra is detected by online AFM (such as Bruker FastScan). If the Ra is too large, the coating speed is reduced. The water-based organic coating is a water-based acrylate coating. Moreover, the water-based acrylate coating includes: 65 parts of water-based acrylate emulsion, 20 parts of water, 5 parts of nano-silica, 2 parts of silane coupling agent, 0.5 part of leveling agent, 0.3 part of defoaming agent; and 6% of the mass of the water-based acrylate emulsion of thermoplastic elastomer. The water-based acrylate emulsion is selected from pure acrylic emulsions. The D50 of the nano-silica is 25 nm. The silane coupling agent is selected from silane coupling agent KH-560. The leveling agent is selected from BYK-346 (polyether modified silicone). The defoaming agent is selected from mineral oil TEGO Foamex 810. The thermoplastic elastomer is selected from linear SBS. The nano-silica is hollow nano-silica, and moreover, the particle size distribution of the nano-silica is 10 - 60 nm. Depositing an inorganic layer: At a temperature of 170°C, a mixed gas of trimethylaluminum and tetraethyl orthosilicate in a pulsed gaseous state is applied to the surface of the organic buffer layer, and then water vapor is pulsed. Such cyclic pulsing is carried out to deposit an inorganic layer with a thickness of 20 nm on the surface of the organic buffer layer. In the mixed gas of trimethylaluminum and tetraethyl orthosilicate, the mass ratio of trimethylaluminum to tetraethyl orthosilicate is 5.5:1. Stacking and encapsulation: After such 10 cycles of organic buffer layer - inorganic layer stacking, after covering the outermost layer with a UV glue with a thickness of 8 μm, UV curing encapsulation is carried out, and then annealing treatment is carried out at a temperature of 110 °C for 2 h to obtain a flexible high - barrier film for electronic packaging; Among them, after stacking 10 cycles, a corresponding multi - layer continuous stacked structure is formed on one side of the substrate.

[0026] Example 4 Compared with Example 1, the difference in this example is that the nano - silica is solid nano - silica, and the rest of the conditions remain unchanged.

[0027] Example 5 Compared with Example 1, the difference in this example is that the particle size distribution range of the nano - silica is 1 - 95 nm, and the rest of the conditions remain unchanged.

[0028] Example 6 Compared with Example 1, the difference in this example is that in the mixed gas of trimethylaluminum and tetraethyl orthosilicate, the mass ratio of trimethylaluminum to tetraethyl orthosilicate is 4:1, and the rest of the conditions remain unchanged.

[0029] Example 7 Compared with Example 1, the difference in this example is that no thermoplastic elastomer is added, and the rest of the conditions remain unchanged.

[0030] Comparative Example 1 Compared with Example 1, the difference in this comparative example is that no tetraethyl orthosilicate is added, and the rest of the conditions remain unchanged.

[0031] Comparative Example 2 Compared with Example 1, the difference in this example is that: Coating the organic buffer layer: On the two surfaces of the activated substrate, a water - based organic coating is coated, and then cured and formed 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; The rest of the conditions remain unchanged.

[0032] Performance tests are carried out on the products obtained in the examples and comparative examples. The specific test methods and test results are as follows: Under the conditions of an ambient temperature of 25 °C and a relative humidity of 50%, a bending test is carried out using a bending test machine of Toyo Seiki of Japan. The bending radius is 3 mm, the bending frequency is 1 Hz, the bending angle is 180°, and 45000 times of bending are carried out. After the bending is completed, SEM is used to observe the surface cracks and measure their maximum crack width. The specific test results are shown in Table 1; In addition, referring to ASTM F1249, before and after the bending starts, the barrier performance (WVTR) of the corresponding product is tested respectively, and the change rate after bending compared with that before bending is calculated. The detailed test results are shown in Table 1; ; It can be seen from the test results in Table 1 that the product obtained by the present invention can improve the anti-bending ability of the product. Before and after bending, the product has smaller cracks and relatively small changes in barrier performance.

[0033] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A preparation method of 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 regulate the surface energy of the two surfaces to be ≥50 mN / m respectively, obtaining an activated substrate; Coating an organic buffer layer: Coating a water-based organic coating on the two surfaces of the activated substrate, and then curing and molding to obtain an organic buffer layer with a moisture content of 15 - 20%, a thickness of 10 - 15 μm, and a roughness Ra of 0.08 - 0.12 μm; Depositing an inorganic layer: Under the condition of a temperature of 170 °C, pulsing a mixed gas of trimethylaluminum and tetraethyl orthosilicate in a gaseous state on the surface of the organic buffer layer, and then pulsing with water vapor, and such cycling pulses are carried out to deposit an inorganic layer with a thickness of 15 - 20 nm on the surface of the organic buffer layer; Stacking and encapsulation: Stacking the organic buffer layer - inorganic layer in this way for 8 - 10 cycles, and then covering with a UV - curable adhesive and annealing to obtain a flexible high - barrier film for electronic packaging.

2. The preparation method of a flexible high-barrier film for electronic packaging according to claim 1, wherein The substrate activation further includes: Using oxygen plasma, under the conditions of a power of 180 - 200 W and a treatment time of 80 - 110 s, performing plasma activation on the upper and lower surfaces of the polymer substrate to regulate the surface energy of the two surfaces to be ≥50 mN / m respectively, obtaining an activated substrate.

3. The preparation method of 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); And the thickness of the polymer substrate is 25 - 50 μm.

4. The preparation method of a flexible high-barrier film for electronic packaging according to claim 1, wherein, The water - based organic coating is a water - based acrylate coating; And the water - based acrylate coating includes: 60 - 65 parts of water - based acrylate emulsion, 15 - 20 parts of water, 3 - 5 parts of nano - silica, 1 - 2 parts of silane coupling agent, 0.3 - 0.5 part of leveling agent, 0.1 - 0.3 part of defoaming agent.

5. The preparation method of a flexible high - barrier film for electronic packaging according to claim 4, wherein The water - based acrylate emulsion is selected from pure acrylic emulsion; The D50 of the nano - silica 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, silane coupling agent KH - 580; The leveling agent is selected from BYK - 346 (polyether - modified silicone); The defoaming agent is selected from mineral oil TEGO Foamex 810.

6. The preparation method of a flexible high-barrier film for electronic packaging according to any one of claims 4 or 5, characterized in that The nano - silica is hollow nano - silica, and the particle size distribution of the nano - silica is 10 - 60 nm.

7. The preparation method of a flexible high-barrier film for electronic packaging according to claim 6, characterized in that, The water - based acrylate coating further includes a thermoplastic elastomer accounting for 4 - 6% of the mass of the water - based acrylate emulsion; The thermoplastic elastomer is selected from linear SBS.

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

1.

9. The preparation method of a flexible high-barrier film for electronic packaging according to claim 1, characterized in that, The covering of the UV - curable adhesive includes: covering a UV adhesive with a thickness of 6 - 8 μm on the outermost layer and then performing UV - curing encapsulation.

10. The preparation method of a flexible high-barrier film for electronic packaging according to claim 1, characterized in that, The annealing includes: annealing treatment for 1 - 2 h under the condition of a temperature of 90 - 110 °C.