A curved metal grid electromagnetic shielding optical window and its preparation method and application

Abstract

The present invention relates to the technical field of electromagnetic shielding materials, and specifically discloses a curved metal mesh electromagnetic shielding optical window and a preparation method and application thereof. The present invention adopts a variable speed laser direct writing method for scanning exposure, thereby improving the line width uniformity of different glue thickness areas; at the same time, metal aluminum is used as the metal shielding material, and an alkaline solution is used to develop and etch it, thereby successfully preparing a curved metal mesh electromagnetic shielding optical window with high line width uniformity. The present invention effectively solves the problems of uneven photoresist coating in the preparation process of the curved metal mesh in the prior art, such as poor line width uniformity and transmittance, difficulty in stripping the metal film, and corrosion of the metal optical window by the metal etching solution. The prepared metal mesh window takes into account both high transmittance and superior electromagnetic shielding performance.

Description

Technical Field

[0001] The invention relates to the technical field of electromagnetic shielding materials, and specifically discloses a curved metal grid electromagnetic shielding optical window and a preparation method and application thereof. Background Art

[0002] With the rapid development of the electromagnetic field, optical windows need to face extremely complex spatial electromagnetic environments during use, which not only requires optical windows to have good environmental impact resistance, but also requires optical windows to have excellent electromagnetic shielding performance and transmittance. As one of the effective methods to achieve electromagnetic shielding of optical windows, metal grid electromagnetic shielding technology has received extensive attention and research.

[0003] There are still many difficulties in the realization of metal grid optical shielding windows, especially in the preparation technology of curved metal grids. The most widely studied are the problems of photoresist coating and metal etching. Due to the large curvature of the curved optical window and the influence of the gravity of the photoresist, the thickness uniformity of the photoresist coated on the curved window is poor regardless of whether the spray coating or spin coating process is used. The photoresist obtained by spin coating will have the problem of thin thickness in the center and thick thickness at the edge; while the photoresist obtained by spray coating will have the problem of thick thickness in the center and thin thickness at the edge. During curved surface lithography, due to the uneven distribution of photoresist thickness, it is very easy to cause the thin surface to be overexposed, and the line width becomes larger; the exposure energy of the thick area is insufficient, the line width becomes smaller and it is very easy to break the line. The problem of uniformity of the thickness of the photoresist directly affects the optical and electromagnetic shielding performance of the curved metal grid.

[0004] The curved metal grid is usually made into a grid pattern on the inner surface of the curved window by photolithography, and then the metal film is evaporated by metal coating, and selectively peeled off to form the curved metal grid. However, due to the certain curvature of the curved optical window, the metal at the edge of the curved window will inevitably be deposited with photoresist on the side during the coating operation, resulting in metal adhesion, difficulty in peeling and increased line breakage rate after subsequent strong ultrasound. Although peeling can be promoted by enhancing the standing wave effect or other photolithography optimization processes, the cost is high and the process is complicated. It is more noteworthy that the metal etching solution used in the prior art will cause a certain degree of corrosion damage to the metal optical window, seriously affecting the service life of the curved metal grid electromagnetic shielding optical window.

[0005] Based on this, developing a curved metal mesh electromagnetic shielding optical window that is easy to operate, low-cost and high-quality has significant progressive significance in the field of electromagnetic shielding materials. Summary of the invention

[0006] In view of the problems of uneven coating of photoresist in the preparation process of curved metal grid in the prior art, such as poor line width uniformity and transmittance, difficulty in stripping of metal film, and corrosion of metal optical window by metal etching solution, the present invention provides a curved metal grid electromagnetic shielding optical window and its preparation method and application. By testing the thickness of the glue in different distribution areas of the optical window in advance, calculating the laser scanning rate corresponding to different glue thicknesses according to the formula, and using the method of laser direct writing variable speed scanning exposure, the exposure dose distribution of different glue thickness areas is realized, and the problem of line width uniformity caused by uneven glue thickness is completely solved. The present invention also realizes the development and etching of the grid pattern by using the method of curved etching of metal aluminum film with alkaline developer, and replaces the traditional stripping process with the wet etching process, which not only avoids the problem of corrosion of the curved optical window by the existing etching solution, but also avoids the problem of complicated stripping operation in the preparation process of the traditional curved grid. The etching method provided by the present invention has a simple operation process and low cost, effectively solves the problems in the preparation process of the curved metal grid electromagnetic shielding window in the prior art, and provides a new idea for the preparation of the curved metal grid electromagnetic shielding window.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] A first aspect of the present invention provides a method for preparing a curved metal grid electromagnetic shielding optical window, comprising the following steps:

[0009] Step 1: Clean the curved optical window with a low boiling point mixed solvent, and dry it to obtain a one-time treated curved optical window;

[0010] Step 2, forming a metal aluminum film, an adhesion promoter layer and a negative photoresist layer in sequence on the surface of the once-treated curved optical window to obtain a sample to be exposed;

[0011] Step 3, testing the photoresist thickness of different areas of the sample to be exposed, determining the laser direct writing scanning rate according to the photoresist thickness, and scanning the sample to be exposed by using a variable speed laser direct writing method to obtain an exposed sample;

[0012] Step 4, immersing the exposed sample in a strong alkaline solution for development and etching, washing, and drying to obtain a curved metal grid electromagnetic shielding optical window;

[0013] In step three, when the photoresist thickness is 3.0μm-5.0μm, the laser direct writing scanning rate is 3.5mm / s-9.5mm / s; when the photoresist thickness is 5.0μm-7.5μm, the laser direct writing scanning rate is 2.0mm / s-7.0mm / s; when the photoresist thickness is 7.5μm-9.0μm, the laser direct writing scanning rate is 1.0mm / s-4.0mm / s.

[0014] Compared with the prior art, the present invention first evaporates a layer of metal aluminum film on the surface of the curved optical window. While evaporating the aluminum film, the surface will be oxidized to form an aluminum oxide film, which can effectively block water and oxygen in the air and prevent further corrosion of the metal, thereby avoiding the impact of metal oxidation and corrosion on the curved metal grid electromagnetic shielding optical window, and to a certain extent improves the service life of the curved electromagnetic shielding window. In addition, aluminum, as the metal with the highest content, has a lower cost than the commonly used gold and copper, but has the same excellent conductivity. Therefore, using aluminum as the metal raw material can effectively control the process cost.

[0015] Furthermore, the present invention tests the photoresist thickness distribution of the curved surface sample to be exposed in advance, and converts the exposure energy into a laser direct writing scanning rate according to the exposure energy required to achieve the set target line width with different photoresist thicknesses. The exposure dose distribution of different photoresist thickness areas is achieved by the curved surface laser direct writing variable speed scanning method. The prepared metal grid has a more uniform line width, and has good transmittance and electromagnetic shielding performance, avoiding the problem of line breakage caused by insufficient exposure energy in the edge or center photoresist thickness areas.

[0016] In addition, since the existing etching solution is mainly an acidic substance, although the etching effect is good, it will inevitably cause damage to the metal optical window, affecting its subsequent performance. The present invention uses a strong alkaline solution for treatment, which serves as both a developer and an etching solution. The metal material can be etched while developing, and the corrosion process replaces the traditional stripping process. It also avoids the problem of damage to the metal optical window caused by the existing acidic etching solution. Therefore, the metal material selected by the present invention needs to be able to react with the alkaline developer, and aluminum, as an amphoteric metal, not only has the characteristics of reacting with alkaline substances, but also meets the requirements of stable chemical properties.

[0017] In summary, the technical solution provided by the present invention achieves the target line width by performing laser direct writing variable speed scanning exposure to different glue thickness areas, which completely solves the problem of line width uniformity caused by uneven glue thickness. The present invention also uses an alkaline developer to develop and etch the curved optical window to prepare a curved aluminum metal mesh optical window, and replaces the traditional stripping process with a wet etching process, which not only avoids the problem of complex stripping operations in the traditional curved mesh preparation process, but also further avoids the problem of corrosion of the curved optical window by the existing acidic etching solution. The method has a simple operation process, low cost, and will not cause damage to the curved metal mesh electromagnetic shielding optical window.

[0018] Preferably, in step 1, the low boiling point mixed solvent is a mixed solvent of acetone and ethanol; wherein the volume ratio of acetone to ethanol is 1-2:2-3.

[0019] Preferably, in step 1, the drying temperature is 110° C.-180° C., and the drying time is 0.5 h-1.5 h.

[0020] Preferably, in step 2, the thickness of the metal aluminum film is 120nm-500nm.

[0021] Preferably, in step 2, the thickness of the adhesion promoter layer is 10 nm-50 nm.

[0022] Preferably, in step 2, the thickness of the negative photoresist layer is 3 μm-9 μm.

[0023] Preferably, in step 2, the metal aluminum film is prepared by evaporation, wherein the evaporation temperature is 100° C.-180° C., and the evaporation rate is 0.8 A / s-3 A / s.

[0024] Preferably, in step 2, the adhesion promoter layer is prepared by fumigation, wherein the fumigation temperature is 175°C-185°C.

[0025] Preferably, in step 2, the negative photoresist layer is prepared by spin coating, wherein the spin coating speed is 1000 rpm-1100 rpm, and the spin coating time is 70s-80s.

[0026] Preferably, in step 2, the raw material of the adhesion promoter layer is hexamethyldisilane.

[0027] Preferably, in step 2, the raw material of the negative photoresist layer is HTIN160 negative photoresist.

[0028] Preferably, in step 3, the calculation formula of the laser direct writing scanning rate is: ; Where v is the laser direct writing scanning rate, in mm / s, I 0 is the laser power, in J / s; X a is the exposure length of the light spot, and the calculation formula is , in mm; C is the proportionality coefficient including the absorption coefficient, and its value is 7.827×10 3 ; D is the exposure line width, in μm; ω(z) is the laser spot radius at different focal planes, in μm; F is the critical exposure threshold for different photoresist thicknesses, in mJ; among them, when the photoresist thickness is 3.0μm-9.0μm, F is 50mJ-200mJ.

[0029] Preferably, in step three, the laser wavelength of the variable speed laser direct writing is 400nm-410nm.

[0030] Preferably, in step three, the target line width of the sample after exposure is 8 μm-20 μm.

[0031] Preferably, in step 4, the strong alkaline solution is any one of a sodium hydroxide solution with a mass concentration of 3%-8% or a potassium hydroxide solution with a mass concentration of 3%-8%.

[0032] Preferably, in step 4, the drying is carried out by blowing with an inert gas, and the gas flow rate of the inert gas is 0.3 Nm 3 / h-0.5Nm 3 / h.

[0033] A second aspect of the present invention provides a curved metal grid electromagnetic shielding optical window, which is manufactured using the method for manufacturing a curved metal grid electromagnetic shielding optical window.

[0034] The third aspect of the present invention provides the application of the curved metal grid electromagnetic shielding optical window in the field of electromagnetic shielding materials.

[0035] In summary, the present invention provides a curved metal grid electromagnetic shielding optical window and its preparation method and application. By testing the optical window glue thickness distribution in advance, calculating the laser scanning rate corresponding to different glue thicknesses according to the formula, and using the laser direct writing variable speed scanning exposure method, the exposure dose distribution of different glue thickness areas is realized, and the line width uniformity problem caused by uneven glue thickness is completely solved. The present invention also realizes the development and etching of the grid pattern by using the method of etching the metal aluminum film on the curved surface with an alkaline developer, and replaces the traditional stripping process with a wet etching process, which not only avoids the problem of complex stripping operation in the traditional curved grid preparation process, but also further avoids the problem of corrosion of the curved optical window by the existing acid etching solution. The problem of line width uniformity caused by uneven glue thickness is solved by curved laser direct writing variable speed scanning. The etching method provided by the present invention has a simple operation process and low cost, and effectively solves the problems of poor line width uniformity and transmittance caused by uneven photoresist coating in the preparation process of the curved metal grid in the prior art, the difficulty of stripping the metal film, and the corrosion of the metal optical window by the metal etching solution, and provides a new idea for the preparation of the curved metal grid electromagnetic shielding window. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Example 1

[0038] This embodiment provides a curved metal grid electromagnetic shielding optical window, comprising the following steps:

[0039] Step 1: Clean the curved optical window with a mixed solvent of acetone and ethanol in a volume ratio of 1:2, and dry it at 120° C. for 1 hour to obtain a treated curved optical window;

[0040] Step 2: at 150° C., a layer of metal aluminum film with a thickness of 200 nm is evaporated on the surface of the first-processed curved optical window at a rate of 1 A / s to obtain a second-processed curved optical window; and then at 180° C., a layer of hexamethyldisilane film with a thickness of 20 nm is fumigated on the surface of the second-processed curved optical window to obtain a third-processed curved optical window;

[0041] Step 3: Spin coating a layer of HTIN160 negative photoresist film with a thickness of 6 μm on the surface of the thrice-processed curved optical window, and drying at 110° C. for 5 min to obtain a sample to be exposed; wherein the spin coating speed is 1100 rpm and the spin coating time is 70 s;

[0042] Step 4: Test the exposure dose required for the target line width to be achieved in the areas of different photoresist thicknesses of the sample to be exposed, adopt a laser direct writing method with a wavelength of 405nm, and use a laser with a laser power of 60mJ / s to perform variable speed laser scanning on the sample to be exposed, and the scanning rate varies according to different photoresist thicknesses, as shown in Table 1, to obtain a target line width uniform, which is a sample after exposure of 15μm;

[0043] Step 5: Immerse the exposed sample in a sodium hydroxide solution with a mass concentration of 3% for development and etching for 5 minutes, wash with deionized water, and use a gas flow rate of 0.4 Nm 3 / h nitrogen blowing method is used to dry the curved metal mesh electromagnetic shielding optical window.

[0044] Table 1 Example 1 Areas of different photoresist thicknesses of the sample to be exposed and their corresponding curved surface laser direct writing scanning rates

[0045]

[0046] Example 2

[0047] This embodiment provides a curved metal grid electromagnetic shielding optical window, comprising the following steps:

[0048] Step 1: Clean the curved optical window with a mixed solvent of acetone and ethanol in a volume ratio of 1.5:2.5, and dry it at 120° C. for 1 hour to obtain a treated curved optical window;

[0049] Step 2: at 150° C., a layer of metal aluminum film with a thickness of 250 nm is evaporated on the surface of the first-processed curved optical window at a rate of 0.9 A / s to obtain a second-processed curved optical window; and then at 180° C., a layer of hexamethyldisilane film with a thickness of 22 nm is fumigated on the surface of the second-processed curved optical window to obtain a third-processed curved optical window;

[0050] Step 3: Spin coating a layer of HTIN160 negative photoresist film with a thickness of 5 μm on the surface of the thrice-processed curved optical window, and drying at 108° C. for 8 min to obtain a sample to be exposed; wherein the spin coating speed is 1000 rpm and the spin coating time is 75 s;

[0051] Step 4: Test the exposure dose required for the target line width to be achieved in the areas of different photoresist thicknesses of the sample to be exposed, adopt a laser direct writing method with a wavelength of 405nm, and use a laser with a laser power of 60mJ / s to perform variable speed laser scanning on the sample to be exposed, and the scanning rate varies according to different photoresist thicknesses, as shown in Table 2, to obtain a target line width uniform, which is 8μm after exposure;

[0052] Step 5: Immerse the exposed sample in a 4% potassium hydroxide solution for development and etching for 5 minutes, wash with deionized water, and use a gas flow rate of 0.5 Nm 3 / h nitrogen blowing method is used to dry the curved metal mesh electromagnetic shielding optical window.

[0053] Table 2 Example 2 Areas of different photoresist thicknesses of the sample to be exposed and their corresponding curved surface laser direct writing scanning rates

[0054]

[0055] Example 3

[0056] This embodiment provides a curved metal grid electromagnetic shielding optical window, comprising the following steps:

[0057] Step 1: Clean the curved optical window with a mixed solvent of acetone and ethanol in a volume ratio of 1.5:3, and dry it at 120° C. for 1 hour to obtain a treated curved optical window;

[0058] Step 2: at 150° C., a layer of metal aluminum film with a thickness of 200 nm is evaporated on the surface of the first-processed curved optical window at a rate of 1 A / s to obtain a second-processed curved optical window; and then at 180° C., a layer of hexamethyldisilane film with a thickness of 200 nm is fumigated on the surface of the second-processed curved optical window to obtain a third-processed curved optical window;

[0059] Step 3: Spin coating a layer of HTIN160 negative photoresist film with a thickness of 6 μm on the surface of the thrice-processed curved optical window, and drying at 110° C. for 5 min to obtain a sample to be exposed; wherein the spin coating speed is 1100 rpm and the spin coating time is 70 s;

[0060] Step 4: Test the exposure dose required for the target line width to be achieved in the areas of different photoresist thicknesses of the sample to be exposed, and use a laser direct writing method with a wavelength of 405nm, and use a laser with a laser power of 60mJ / s to perform variable speed laser scanning on the sample to be exposed. The scanning rate varies according to different photoresist thicknesses, as shown in Table 3, and the target line width is uniform, which is a sample after exposure of 10μm;

[0061] Step 5: Immerse the exposed sample in a sodium hydroxide solution with a mass concentration of 3% for development and etching for 5 minutes, wash with deionized water, and use a gas flow rate of 0.4 Nm 3 / h nitrogen blowing method is used to dry the curved metal mesh electromagnetic shielding optical window.

[0062] Table 3 Example 3 Areas of different photoresist thicknesses of the sample to be exposed and their corresponding curved surface laser direct writing scanning rates

[0063]

[0064] Comparative Example 1

[0065] This comparative example provides a curved metal grid electromagnetic shielding optical window, which is different from Example 1 in that the laser scanning rate is different, and includes the following steps:

[0066] Step 1: Clean the curved optical window with a mixed solvent of acetone and ethanol in a volume ratio of 1:2, and dry it at 120° C. for 1 hour to obtain a treated curved optical window;

[0067] Step 2: at 150° C., a layer of metal aluminum film with a thickness of 200 nm is evaporated on the surface of the first-processed curved optical window at a rate of 1 A / s to obtain a second-processed curved optical window; and then at 180° C., a layer of hexamethyldisilane film with a thickness of 20 nm is fumigated on the surface of the second-processed curved optical window to obtain a third-processed curved optical window;

[0068] Step 3: Spin coating a layer of HTIN160 negative photoresist film with a thickness of 6 μm on the surface of the thrice-processed curved optical window, and drying at 110° C. for 5 min to obtain a sample to be exposed; wherein the spin coating speed is 1100 rpm and the spin coating time is 70 s;

[0069] Step 4: Test the exposure dose required for the target line width to be achieved in the areas of different photoresist thicknesses of the sample to be exposed, and use a laser direct writing method with a wavelength of 405nm, and use a laser with a laser power of 100mJ / s to perform variable speed laser scanning on the sample to be exposed. The scanning rate varies according to different photoresist thicknesses, as shown in Table 4, and the target line width is uneven, which is 15μm-30μm for the exposed sample;

[0070] Step 5: Immerse the exposed sample in a sodium hydroxide solution with a mass concentration of 3% for development and etching for 5 minutes, wash with deionized water, and use a gas flow rate of 0.4 Nm 3 / h nitrogen blowing method is used to dry the curved metal mesh electromagnetic shielding optical window.

[0071] Table 4 Comparative Example 1 Areas of different photoresist thicknesses of the exposed sample and their corresponding curved surface laser direct writing scanning rates

[0072]

[0073] Comparative Example 2

[0074] This comparative example provides a curved metal grid electromagnetic shielding optical window, which is different from Example 1 in that: after developing with an alkaline developer, etching with an acidic solution includes the following steps:

[0075] Step 1: Clean the curved optical window with a mixed solvent of acetone and ethanol in a volume ratio of 1:2, and dry it at 120° C. for 1 hour to obtain a treated curved optical window;

[0076] Step 2: at 150° C., a layer of metal aluminum film with a thickness of 200 nm is evaporated on the surface of the first-processed curved optical window at a rate of 1 A / s to obtain a second-processed curved optical window; and then at 180° C., a layer of hexamethyldisilane film with a thickness of 20 nm is fumigated on the surface of the second-processed curved optical window to obtain a third-processed curved optical window;

[0077] Step 3: Spin coating a layer of HTIN160 negative photoresist film with a thickness of 6 μm on the surface of the thrice-processed curved optical window, and drying at 110° C. for 5 min to obtain a sample to be exposed; wherein the spin coating speed is 1100 rpm and the spin coating time is 70 s;

[0078] Step 4: testing the exposure dose required for the target line width to be achieved in the regions of different photoresist thicknesses of the sample to be exposed, and performing variable speed laser scanning on the sample to be exposed by laser direct writing with a wavelength of 405 nm, wherein the scanning rate varies according to different photoresist thicknesses, as shown in Table 1, and the target line width is uniform, which is a sample after exposure of 15 μm;

[0079] Step 5: Immerse the exposed sample in a sodium hydroxide solution with a mass concentration of 3% for 2 minutes, wash with deionized water, and use a gas flow rate of 0.4 Nm 3 / h nitrogen blowing method to dry, to obtain the developed sample;

[0080] Step 6: The developed sample was immersed in a hydrochloric acid solution with a mass concentration of 3% for etching for 5 minutes, washed with deionized water, and a gas flow rate of 0.4 Nm 3 / h nitrogen blowing method is used to dry the curved metal mesh electromagnetic shielding optical window.

[0081] The present invention conducts a yield test (1000 pieces) on the curved metal mesh electromagnetic shielding optical windows obtained in Examples 1-3 and Comparative Examples 1-2, tests the optical transmittance using a Fourier transform infrared spectrometer, and conducts an electromagnetic shielding performance test according to the GJB 8820-2015 standard. The specific results are shown in Table 5.

[0082] Table 5 Performance test results of the curved metal grid electromagnetic shielding optical windows obtained in various embodiments and comparative examples

[0083]

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a curved metal grid electromagnetic shielding optical window, characterized in that: The steps include: Step 1: Clean the curved optical window with a low boiling point mixed solvent, and dry it to obtain a one-time treated curved optical window; Step 2, forming a metal aluminum film, an adhesion promoter layer and a negative photoresist layer in sequence on the surface of the once-treated curved optical window to obtain a sample to be exposed; Step 3, testing the photoresist thickness of different areas of the sample to be exposed, determining the laser direct writing scanning rate according to the photoresist thickness, and scanning the sample to be exposed by using a variable speed laser direct writing method to obtain an exposed sample; Step 4, immersing the exposed sample in a strong alkaline solution for development and etching, washing, and drying to obtain a curved metal grid electromagnetic shielding optical window; In step 3, when the thickness of the photoresist is 3.0 μm-5.0 μm, the laser direct writing scanning rate is 3.5 mm / s-9.5 mm / s; when the thickness of the photoresist is 5.0 μm-7.5 μm, the laser direct writing scanning rate is 2.0 mm / s-7.0 mm / s; when the thickness of the photoresist is 7.5 μm-9.0 μm, the laser direct writing scanning rate is 1.0 mm / s-4.0 mm / s; In step 3, the calculation formula of the laser direct writing scanning rate is: Where v is the laser direct writing scanning rate, in mm / s, I 0 is the laser power, in J / s; X a is the exposure length of the light spot, and the calculation formula is , in mm; C is the proportionality coefficient including the absorption coefficient, and its value is 7.827×10 3 ; D is the exposure line width, in μm; ω(z) is the laser spot radius at different focal planes, in μm; F is the critical exposure threshold for different photoresist thicknesses, in mJ; among them, when the photoresist thickness is 3.0μm-9.0μm, F is 50mJ-200mJ.

2. The method for preparing a curved metal grid electromagnetic shielding optical window according to claim 1, characterized in that: In step 1, the low boiling point mixed solvent is a mixed solvent of acetone and ethanol; wherein the volume ratio of acetone to ethanol is 1-2:2-3.

3. The method for preparing a curved metal grid electromagnetic shielding optical window according to claim 1, characterized in that: In step 2, the thickness of the metal aluminum film is 120nm-500nm; and / or In step 2, the thickness of the adhesion promoter layer is 10nm-50nm; and / or In step 2, the thickness of the negative photoresist layer is 3 μm-9 μm.

4. The method for preparing a curved metal grid electromagnetic shielding optical window according to claim 1 or 3, characterized in that: In step 2, the metal aluminum film is prepared by evaporation, wherein the evaporation temperature is 100° C.-180° C., and the evaporation rate is 0.8A / s-3A / s; and / or In step 2, the adhesion promoter layer is prepared by fumigation, wherein the fumigation temperature is 175° C.-185° C.; and / or In step 2, the negative photoresist layer is prepared by spin coating, wherein the rotation speed of the spin coating is 1000 rpm-1100 rpm, and the spin coating time is 70 s-80 s.

5. The method for preparing a curved metal grid electromagnetic shielding optical window according to claim 1, characterized in that: In step 2, the raw material of the adhesion promoter layer is hexamethyldisilane; and / or In step 2, the raw material of the negative photoresist layer is HTIN160 negative photoresist.

6. The method for preparing a curved metal grid electromagnetic shielding optical window according to claim 1, characterized in that: In step 3, the laser wavelength of the variable speed laser direct writing is 400nm-410nm; and / or In step three, the target line width of the sample after exposure is 8 μm-20 μm.

7. The method for preparing a curved metal grid electromagnetic shielding optical window according to claim 1, characterized in that: In step 4, the strong alkaline solution is any one of a sodium hydroxide solution with a mass concentration of 3%-8% or a potassium hydroxide solution with a mass concentration of 3%-8%; and / or In step 4, the drying is carried out by blowing with inert gas, and the gas flow rate of the inert gas is 0.3Nm 3 / h-0.5Nm 3 / h.

8. A curved metal grid electromagnetic shielding optical window, characterized in that: The optical window is prepared by the method for preparing a curved metal grid electromagnetic shielding optical window as described in any one of claims 1 to 7.

9. Application of the curved metal grid electromagnetic shielding optical window as claimed in claim 8 in the field of electromagnetic shielding materials.

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