Film layer structure, method for producing same and optical device

Abstract

The application provides a film layer structure, a preparation method thereof and an optical device. The film layer structure comprises a substrate, a first film group for inhibiting stress variation generated by the substrate, a second film group for realizing optical performance of the film layer structure, and a third film group for inhibiting stress variation generated by the second film group. The thickness of the second film group is greater than the thickness of the first film group and / or the thickness of the third film group. The first film group is added on the surface of the substrate, which helps to inhibit residual stress generated by the substrate during film plating. The thickness of the second film group is the largest, which is to ensure that the film layer structure has the required optical performance. The thickness of the third film group is smaller than the thickness of the second film group, which helps to inhibit residual stress generated during plating of the second film group, thereby improving the situation that internal stress increases due to thermal influence during plating of the film layer structure.

Description

Technical Field

[0001] This application relates to the field of optical materials, and more particularly to a film structure, its preparation method, and an optical device thereof. Background Technology

[0002] Today, optical devices face increasing application demands. To improve the performance of optical devices, coating is typically performed in the post-processing stage, which helps to enhance their performance. However, during the coating process, the internal stress of the optical device increases due to heat. Summary of the Invention

[0003] This application provides a film structure, its preparation method, and an optical device, which helps to improve the problem of increased internal stress in optical devices during the coating process.

[0004] To achieve the above objectives, in a first aspect, embodiments of this application provide a membrane structure, the membrane structure comprising:

[0005] Substrate;

[0006] A first membrane assembly is used to suppress stress changes generated by the substrate, and the first membrane assembly is disposed on the substrate;

[0007] The second film assembly is used to realize the optical performance of the film structure, and the second film assembly is disposed on the first film assembly;

[0008] A third membrane assembly is used to suppress stress changes generated by the second membrane assembly, and the third membrane assembly is disposed on the second membrane assembly;

[0009] The thickness of the second membrane group is greater than the thickness of the first membrane group, and the thickness of the second membrane group is greater than the thickness of the third membrane group.

[0010] Optionally, in some embodiments of this application, the ratio of the thickness of the critical membrane of the second membrane group near the first membrane group to the thickness of the critical membrane of the first membrane group near the second membrane group is greater than or equal to 2; and / or

[0011] The ratio of the thickness of the critical membrane of the second membrane group near the third membrane group to the thickness of the critical membrane of the third membrane group near the second membrane group is greater than or equal to 2.

[0012] Optionally, in some embodiments of this application, the thickness of the first film assembly ranges from 100 nm to 230 nm; and / or

[0013] The thickness of the sub-membrane in the first membrane group ranges from 15 nm to 50 nm.

[0014] Optionally, in some embodiments of this application, the first membrane assembly includes a plurality of alternately stacked first sub-membranes and second sub-membranes, wherein the materials of the first sub-membranes and the second sub-membranes are different; and / or the thicknesses of the first sub-membranes and the second sub-membranes range from 15 nm to 50 nm; and / or

[0015] The ratio of the thickness of the first sub-membrane to the thickness of the second sub-membrane is 0.5 to 1.

[0016] Optionally, in some embodiments of this application, the thickness of the second film assembly ranges from 1845 nm to 3300 nm; and / or

[0017] The ratio of the thickness of the second membrane assembly to the thickness of the membrane structure is 0.78 to 0.93; and / or

[0018] The thickness of the sub-membrane of the second membrane group ranges from 40 nm to 185 nm.

[0019] Optionally, in some embodiments of this application, the second membrane group includes a plurality of alternately stacked third and fourth sub-membranes, wherein the materials of the third sub-membranes and the fourth sub-membranes are different.

[0020] Optionally, in some embodiments of this application, the thickness of the third sub-film ranges from 100 nm to 185 nm; and / or the thickness of the fourth sub-film ranges from 40 nm to 80 nm.

[0021] Preferably, the ratio of the thickness of the third sub-membrane to the thickness of the fourth sub-membrane is 1.8 to 3.2.

[0022] Optionally, in some embodiments of this application, the thickness of the third film assembly ranges from 140 nm to 370 nm; and / or

[0023] The thickness of the sub-membrane in the third membrane group ranges from 35 nm to 95 nm.

[0024] Optionally, in some embodiments of this application, the third membrane assembly includes a plurality of alternately stacked fifth and sixth sub-membranes, wherein the materials of the fifth sub-membranes and the sixth sub-membranes are different; and / or

[0025] The ratio of the thickness of the fifth sub-membrane to the thickness of the sixth sub-membrane is 1 to 2.

[0026] Optionally, in some embodiments of this application, the number of sub-membranes within the second membrane group is odd; and / or

[0027] The number of sub-membranes in the first membrane group / third membrane group is even.

[0028] Optionally, in some embodiments of this application, each sub-membrane within the first membrane group, the second membrane group, and the third membrane group includes a first material or a second material, wherein the first material is a material for resisting compressive stress on an object; and / or the second material is a material for resisting tensile stress on an object.

[0029] Optionally, in some embodiments of this application, the first material includes at least one of aluminum silicon oxide, silicon oxide, aluminum silicon nitride, and silicon nitride; and / or

[0030] The second material includes at least one of niobium oxide, chromium oxide, titanium oxide, niobium titanium oxide, chromium titanium oxide, and niobium chromium oxide.

[0031] Optionally, in some embodiments of this application, the substrate includes any one of glass, crystal, ceramic, and plastic.

[0032] Optionally, in some embodiments of this application, the first membrane group, the second membrane group, and the third membrane group are stacked on one or both sides of the substrate.

[0033] Optionally, in some embodiments of this application, the infrared transmittance of the film structure in the wavelength range of 800 nm to 1400 nm is 20% to 98%.

[0034] Secondly, embodiments of this application provide a method for preparing a membrane structure, the method comprising the following steps:

[0035] Provide base materials;

[0036] A first film assembly is obtained by depositing a film on the substrate;

[0037] A second membrane assembly is obtained by depositing a film on the first membrane assembly;

[0038] A third membrane assembly is obtained by depositing a film on the second membrane assembly, thus forming the membrane structure.

[0039] Optionally, in some embodiments of this application, the first membrane assembly is prepared using the following steps:

[0040] A first material is deposited on the substrate to obtain a first sub-film;

[0041] A second material is deposited on the first sub-film to obtain a second sub-film;

[0042] The first sub-film and the second sub-film are repeatedly deposited to achieve a first film assembly with a preset thickness.

[0043] Optionally, in some embodiments of this application, the second membrane assembly is prepared using the following steps:

[0044] A first material is deposited on the first membrane assembly to obtain a third sub-membrane;

[0045] A second material is deposited on the third sub-film to obtain a fourth sub-film;

[0046] The third and fourth sub-films are repeatedly deposited to achieve a second film group with a preset thickness.

[0047] Optionally, in some embodiments of this application, the third membrane assembly is prepared using the following steps:

[0048] A first material is deposited on the second membrane group to obtain a fifth sub-membrane;

[0049] A second material is deposited on the fifth sub-film to obtain a sixth sub-film;

[0050] The fifth and sixth sub-films are repeatedly deposited to achieve a third film group with a preset thickness.

[0051] Thirdly, embodiments of this application provide an optical device, including the film structure as described above or the film structure prepared by the method described above.

[0052] This application provides a film structure comprising a substrate and a first film group, a second film group, and a third film group sequentially stacked on the substrate. The thickness of the second film group is greater than the thickness of the first film group, and the thickness of the second film group is greater than the thickness of the third film group. The film structure of this application includes a first film group, a second film group, and a third film group. Adding a first film group between the substrate and the second film group helps suppress residual stress generated on the substrate during coating. The second film group has the largest thickness to ensure the film structure achieves its optical performance. The thickness of the third film group is less than the thickness of the second film group, which helps suppress residual stress generated during the fabrication of the second film group, thereby improving the situation where internal stress increases due to thermal effects during the fabrication of the film structure. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 These are schematic diagrams of the membrane structure in some embodiments of this application;

[0055] Figure 2 This is a process flow diagram of the membrane structure in some embodiments of this application;

[0056] Figure 3 This is an infrared transmittance characterization diagram of Embodiment 1 of this application;

[0057] Figure 4 This is a diagram of the curled state of the film structure after deposition in Comparative Example 2 of this application;

[0058] Figure 5 This is a diagram of the curled state of the film structure after deposition, as shown in Comparative Example 3 of this application.

[0059] Explanation of reference numerals in the attached figures:

[0060] 100. Membrane structure;

[0061] 110. Substrate; 120. First membrane assembly; 130. Second membrane assembly; 140. Third membrane assembly. Detailed Implementation

[0062] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0063] Nowadays, optical devices are facing increasing application demands. In order to improve the performance requirements of optical devices, coating is usually performed in the post-processing of optical devices, and coating helps to improve the performance requirements of optical devices.

[0064] However, current coating methods tend to increase the internal stress of devices during the coating process.

[0065] In view of this, this application provides a film structure, a method for preparing the film, and an optical device thereof, which helps to improve the phenomenon that existing coating methods easily lead to an increase in internal stress in the device during the coating process.

[0066] In a first aspect, this application provides a membrane structure 100, see reference. Figure 1 The membrane structure 100 may include:

[0067] Substrate 110;

[0068] The first membrane assembly 120 is used to suppress stress changes generated by the substrate, and the first membrane assembly 120 is disposed on the substrate 110;

[0069] The second film group 130 is used to realize the optical performance of the film structure, and the second film group 130 is disposed on the first film group 120.

[0070] The third membrane module 140 is used to suppress the stress changes generated by the second membrane module 130, and the third membrane module 140 is disposed on the second membrane module 130.

[0071] The thickness of the second membrane group 130 is greater than the thickness of the first membrane group 120, and the thickness of the second membrane group 130 is greater than the thickness of the third membrane group 140.

[0072] By adopting the above scheme, the film structure of this application includes a first film group, a second film group, and a third film group. Adding the first film group between the substrate and the second film group helps to suppress the residual stress generated on the substrate during coating. Limiting the thickness of the second film group to be greater than the thickness of the first film group and / or the third film group is to ensure that the film structure meets the required optical performance indicators. The thickness of the third film group is less than the thickness of the second film group, which helps to suppress the residual stress generated on the second film group during preparation, thereby improving the situation where the internal stress of the film structure increases due to thermal influence during preparation.

[0073] In some embodiments of this application, the ratio of the thickness of the critical membrane of the second membrane group near the first membrane group to the thickness of the critical membrane of the first membrane group near the second membrane group can be greater than or equal to 2.

[0074] In some embodiments of this application, the ratio of the thickness of the critical membrane of the second membrane group near the third membrane group to the thickness of the critical membrane of the third membrane group near the second membrane group can be greater than or equal to 2.

[0075] With the above scheme, since the main function of the second film group is to meet the required optical performance, the second film group needs to have a certain thickness. Correspondingly, the thickness of the sub-films of the second film group will also increase. The embodiments of this application limit the thickness of the critical film of the second film group near the first film group / third film group to be more than twice or more the thickness of the critical film of the first film group / third film group near the second film group, which helps to ensure that the second film group meets the required optical performance requirements.

[0076] In some embodiments of this application, the number of submembranes within the first membrane group / third membrane group can be an even number. Further, the number of submembranes in the first membrane group can be 2 to 10. For example, the number of submembranes in the first membrane group can be 2, 4, 6, 8, or 10.

[0077] In some embodiments of this application, the number of submembranes in the second membrane group can be an odd number. Further, the number of submembranes in the second membrane group can be 15 to 31. For example, the number of submembranes in the second membrane group can be 15, 17, 19, 21, 23, 25, 27, 29 or 31.

[0078] In some embodiments of this application, the thickness of the first membrane group ranges from 100 nm to 230 nm.

[0079] By adopting the above scheme, the thickness of the first film group is set to 100nm to 230nm. When the film is deposited on the substrate, the substrate generates residual stress due to heat during the deposition process. The first film group in this range can offset or alleviate these residual stresses through its own stress characteristics, effectively absorbing and dispersing the stress of the substrate, thereby preventing the substrate from deforming or being damaged due to stress concentration.

[0080] In some embodiments of this application, the first membrane group includes a plurality of alternatingly stacked first sub-membranes and second sub-membranes, wherein the materials of the first sub-membranes and the second sub-membranes are different.

[0081] By adopting the above scheme, the first sub-membrane and the second sub-membrane are made of different materials, and the sub-membranes of different materials are stacked alternately, which can effectively balance and offset the stress differences between the membrane layers.

[0082] In some embodiments of this application, the thicknesses of the first sub-film and the second sub-film range from 15 nm to 50 nm. For example, the thickness of the first sub-film can be 15 nm, 20 nm, 30 nm, 31 nm, or any value between two adjacent values. For example, the thickness of the second sub-film can be 22.5 nm, 28 nm, 32 nm, 45 nm, 46 nm, or any value between two adjacent values.

[0083] By adopting the above scheme, the thickness of the first sub-film and the second sub-film is 15nm to 50nm. The thickness of the first sub-film and the second sub-film is relatively thin, and the stress distribution of the first sub-film and the second sub-film is relatively uniform, which is beneficial to reducing the stress concentration problem of the film structure.

[0084] In some embodiments of this application, the ratio of the thickness of the first sub-membrane to the thickness of the second sub-membrane ranges from 0.5 to 1. Exemplarily, the ratio of the thickness of the first sub-membrane to the thickness of the second sub-membrane can be 0.5, 0.6, 0.7, 0.8, 0.9, 1, or any value between two adjacent values ​​mentioned above.

[0085] By adopting the above scheme, the ratio of the thickness of the first sub-film to the thickness of the second sub-film is set to 0.5 to 1, indicating that the thickness of the first sub-film is less than or equal to the thickness of the second sub-film. Since the ratio is greater than or equal to 0.5, it indicates that the thickness of the first sub-film is close to the thickness of the second sub-film. This setting can suppress the residual stress of the substrate.

[0086] In some embodiments of this application, the thickness of the second membrane group ranges from 1845 nm to 3300 nm. Exemplarily, the thickness of the second membrane group can be 1845 nm, 2152 nm, 2360 nm, 2425 nm, 2662 nm, 2732 nm, 2978 nm, 3115 nm, 3300 nm, or any value between two adjacent values ​​mentioned above.

[0087] By adopting the above scheme, the thickness of the second film group is much greater than that of the first film group, which helps to ensure the optical performance of the film structure. The film structure made by the second film group within the above thickness range can achieve high transmittance in the infrared region.

[0088] In some embodiments of this application, the ratio of the thickness of the second membrane group to the thickness of the membrane structure can be from 0.78 to 0.93. Exemplarily, the ratio of the thickness of the second membrane group to the thickness of the membrane structure can be 0.78, 0.80, 0.82, 0.84, 0.86, 0.88, 0.90, 0.93, and any value between two adjacent values ​​mentioned above.

[0089] By adopting the above scheme, the ratio of the thickness of the second membrane group to the thickness of the membrane structure in the embodiments of this application is 0.78 to 0.93, indicating that the thickness of the second membrane group is relatively large relative to the overall thickness of the membrane structure. According to the performance requirements of the membrane structure, the material selection of the second membrane group is adjusted to ensure that the membrane structure meets the above performance requirements.

[0090] In some embodiments of this application, the thickness of the sub-membrane of the second membrane group can range from 40 nm to 185 nm. For example, the thickness of the sub-membrane of the second membrane group can be 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 185 nm, or any value between two adjacent values ​​mentioned above.

[0091] By adopting the above scheme, the thickness of the sub-film of the second film group is set to be 40nm to 185nm. Compared with the sub-film of the first film group, the average thickness of the sub-film of the second film group is greater than the average thickness of the sub-film of the first film group. Setting the average thickness of the sub-film of the second film group to be larger is beneficial to ensuring that the second film group meets the required optical performance.

[0092] In the second film group of this application embodiment, the thickness of each film layer is between 40 nm and 180 nm, and the overall thickness of the second film group is between 1845 nm and 3300 nm. This is because, according to the performance requirements of the film layer structure, limiting the thickness of each film layer in the second film group to at least 40 nm and the total thickness of the second film group to at least 1845 nm helps to ensure the optical performance required by the film layer structure.

[0093] In some embodiments of this application, the second membrane group includes a plurality of alternately stacked third and fourth sub-membranes, the materials of the third and fourth sub-membranes being different.

[0094] By adopting the above scheme, the third and fourth sub-membranes are made of different materials, and the sub-membranes of different materials are stacked alternately, which can effectively balance and offset the stress differences between the membrane layers.

[0095] In some embodiments of this application, the thickness of the third sub-film can range from 80 nm to 185 nm. Exemplarily, the thickness of the third sub-film can be 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 185 nm, or any value between two adjacent values ​​mentioned above.

[0096] In some embodiments of this application, the thickness of the fourth sub-film can range from 40 nm to 80 nm. For example, the thickness of the fourth sub-film can be 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, or any value between two adjacent values ​​mentioned above.

[0097] In some embodiments of this application, the ratio of the thickness of the third sub-membrane to the thickness of the fourth sub-membrane can be from 1.8 to 3.2. Further, the ratio of the thickness of the third sub-membrane to the thickness of the fourth sub-membrane can be from 2 to 3. Exemplarily, the ratio of the thickness of the third sub-membrane to the thickness of the fourth sub-membrane can be 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, or any value between two adjacent values ​​mentioned above.

[0098] It should be noted that the design principle of the sub-films in the second film group is to make the film structure have high transmittance at a specific wavelength, while making the color of the film structure more transparent. The thickness ratio of the third sub-film to the fourth sub-film layer in the second film group is limited to 2 to 3, which helps to ensure that the film structure meets the required optical performance requirements.

[0099] In some embodiments of this application, the thickness of the third membrane can range from 140 nm to 370 nm. Exemplarily, the thickness of the third membrane can be 140 nm, 160 nm, 180 nm, 200 nm, 210 nm, 230 nm, 250 nm, 270 nm, 290 nm, 310 nm, 330 nm, 350 nm, 370 nm, or any value between two adjacent values ​​mentioned above.

[0100] By adopting the above scheme, the thickness of the third membrane in this application embodiment ranges from 140nm to 370nm. Since the thickness of the second membrane is large, the stress change generated during preparation is large. The thickness of the third membrane is smaller than the thickness of the second membrane, so the residual stress generated by the second membrane can be suppressed.

[0101] In some embodiments of this application, the third membrane group includes a plurality of alternately stacked fifth and sixth sub-membranes, the materials of the fifth and sixth sub-membranes being different.

[0102] By adopting the above scheme, the fifth and sixth sub-membranes are made of different materials, and the sub-membranes of different materials are stacked alternately, which can effectively balance and offset the stress differences between the membrane layers.

[0103] In some embodiments of this application, the thicknesses of the fifth and sixth sub-films range from 35 nm to 95 nm. For example, the thickness of the fifth sub-film can be 35 nm, 53 nm, 55 nm, 67 nm, 69 nm, 90 nm, 95 nm, or any value between two adjacent values; the thickness of the sixth sub-film can be 35 nm, 36 nm, 38 nm, 45 nm, 63 nm, 65 nm, 89 nm, 91 nm, 95 nm, or any value between two adjacent values.

[0104] In some embodiments of this application, the ratio of the thickness of the fifth sub-membrane to the thickness of the sixth sub-membrane can be 1 to 2. Exemplarily, the ratio of the thickness of the fifth sub-membrane to the thickness of the sixth sub-membrane can be 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, and any value between two adjacent values ​​mentioned above.

[0105] It should be noted that the design principle for the thickness of the sub-membrane in the third membrane group needs to suppress the residual stress of the second membrane group. The thickness ratio of the fifth sub-membrane to the sixth sub-membrane is 1 to 2. This range of thickness ratio can offset the residual stress of the second membrane group to a certain extent.

[0106] In some embodiments of this application, the substrate may include a rigid substrate or a flexible substrate.

[0107] By adopting the above solution, when the film structure of this application includes a rigid substrate, the residual stress generated by the rigid substrate can be reduced during the preparation of the film structure, thereby solving the problem that the film structure is prone to cracking and cannot form a film.

[0108] In some embodiments of this application, the rigid substrate may include at least one of glass, crystal, and ceramic.

[0109] By adopting the above scheme, when the membrane structure of this application includes a flexible substrate, the preparation of the first membrane assembly of this application on the flexible substrate helps to reduce the residual stress generated by the flexible substrate, thereby preventing the membrane structure from curling.

[0110] In some embodiments of this application, the flexible substrate may include plastic. Exemplarily, the plastic material may be at least one of PP, PE, PVC, and PET.

[0111] In some embodiments of this application, at least one of the first sub-membrane, second sub-membrane, third sub-membrane, fourth sub-membrane, fifth sub-membrane, and sixth sub-membrane includes a first material or a second material, wherein the first material can be used to resist the compressive stress of an object, and the second material can be used to resist the tensile stress of an object.

[0112] It is understandable that, since the materials of the first and second sub-films are different, the materials of the third and fourth sub-films are different, the materials of the fifth and sixth sub-films are different, the materials of the two critical films of the first and second film groups are different, and the materials of the two critical films of the second and third film groups are different, and since the first material is used to resist the compressive stress of an object and the second material is used to resist the tensile stress of an object, the interaction of the first, second, third, fourth, fifth, and sixth sub-films can reduce the stress concentration of the substrate, ensure that the film structure meets the required optical requirements, and at the same time slow down the bending of the film structure.

[0113] In some embodiments of this application, the first material includes at least one of aluminum silicon oxide, silicon oxide, aluminum silicon nitride, and silicon nitride. Exemplarily, the first material includes aluminum silicon oxide or silicon nitride.

[0114] By adopting the above solution, the first material in the embodiments of this application needs to meet the requirement of a low coefficient of thermal expansion. Aluminum silicon oxide, silicon oxide, aluminum silicon nitride, and silicon nitride are all compressive stress materials with low coefficients of thermal expansion, thus satisfying the requirements for the first material in the embodiments of this application.

[0115] In some embodiments of this application, the second material includes at least one selected from niobium oxide, chromium oxide, titanium oxide, titanium niobium oxide, titanium chromium oxide, and chromium niobium oxide. Exemplarily, the second material includes niobium oxide, chromium oxide, or titanium oxide.

[0116] By adopting the above solution, the second material in the embodiments of this application needs to meet a large coefficient of thermal expansion. Niobium oxide, chromium oxide, and titanium oxide are all second materials with large coefficients of thermal expansion, which helps to meet the selection of the second material in the embodiments of this application.

[0117] It should be noted that the material selection for the first sub-membrane needs to be determined based on the substrate. Once the first material is selected for the first sub-membrane, the second sub-membrane uses the opposite material. The third and fifth sub-membranes use the same material as the first sub-membrane, and the fourth and sixth sub-membranes use the same material as the second sub-membrane.

[0118] In some embodiments of this application, the first membrane assembly, the second membrane assembly, and the third membrane assembly are stacked on one or both sides of the substrate.

[0119] In some embodiments of this application, the infrared transmittance of the film structure at wavelengths greater than 800 nm is greater than 20%. Further, the infrared transmittance of the film structure at wavelengths from 800 nm to 1400 nm ranges from 20% to 98%.

[0120] Secondly, this application also provides a method for preparing a membrane structure, for preparing the aforementioned membrane structure, see reference. Figure 2 The preparation method may include the following steps:

[0121] S100, providing substrate;

[0122] S200, Deposit a film on a substrate to obtain a first film assembly;

[0123] S300, Deposit a film on the first membrane assembly to obtain a second membrane assembly;

[0124] S400, deposit a film on the second membrane group to obtain the third membrane group, and obtain the membrane structure.

[0125] In some embodiments of this application, a pretreatment of the substrate is added between step S100 and step S200 to clean and treat the substrate surface.

[0126] In some embodiments of this application, in steps S200 to S400, the coating method may be magnetron sputtering.

[0127] In some embodiments of this application, the first membrane assembly can be prepared using the following steps:

[0128] S201. Deposit a first material onto a substrate to obtain a first subfilm;

[0129] S202, deposit a second material on the first sub-film to obtain a second sub-film;

[0130] S203. Repeatedly deposit the first sub-film and the second sub-film to achieve the first film group with a preset thickness.

[0131] In some embodiments of this application, the second membrane assembly can be prepared using the following steps:

[0132] S301. Deposit a first material onto the first membrane assembly to obtain a third sub-membrane;

[0133] S302, deposit a second material on the third sub-film to obtain a fourth sub-film;

[0134] S303, Repeatedly deposit the third and fourth sub-films to achieve the second film group with a preset thickness.

[0135] In some embodiments of this application, the third membrane assembly can be prepared using the following steps:

[0136] S401. Deposit the first material onto the second membrane assembly to obtain the fifth sub-membrane;

[0137] S402, deposit a second material on the fifth sub-film to obtain a sixth sub-film;

[0138] S403. Repeatedly deposit the fifth and sixth sub-films to achieve the third film group with a preset thickness.

[0139] In some embodiments of this application, the first film group, the second film group, and the third film group are deposited in the same way. The following example uses silicon-aluminum oxide as the first material and niobium oxide as the second material to illustrate the deposition of the second film group. The specific deposition process includes the following steps:

[0140] S301, Vacuuming:

[0141] Place the substrate on the fixture of the sputtering machine and evacuate it to a vacuum level below 0.003 Pa;

[0142] S302, Pretreatment of substrate:

[0143] Argon gas is introduced into the machine, the rotating frame is opened, and after the gas stabilizes, the ion source is turned on to perform ion cleaning on the surface of the substrate and the surface of the target material.

[0144] S303, with argon gas continuously supplied, turn on the silicon target and aluminum target, introduce oxygen, and deposit silicon aluminum oxide on the substrate surface. The coating temperature is 70℃ to 110℃, the vacuum degree is 0.1pa, and the time is 30s to 150s.

[0145] S304, with argon gas continuously supplied, the niobium target is turned on, oxygen is introduced, and niobium oxide is deposited on the substrate surface. The coating temperature is 70℃ to 110℃, the vacuum degree is 0.1pa, and the time is 20s to 100s.

[0146] S305, cyclic steps S303 and 304, deposit 20 to 50 layers to obtain the film structure.

[0147] Understandably, step S3201 achieves the purpose of vacuuming, so that the experimental environment is in a vacuum. Step S302 performs ion cleaning on the substrate surface and the target surface. Step S303 deposits a silicon-aluminum oxide material layer, and step S304 deposits a niobium oxide material layer.

[0148] Thirdly, this application also provides an optical device, including the film structure as described above or the film structure prepared by the method described above.

[0149] It is understandable that, since the film structure has high transmittance in the infrared wavelength region, optical devices that include the aforementioned high-transmittance film structure also have high transmittance.

[0150] For example, an optical device may include a long-pass filter. A long-pass filter is an optical device that allows light with wavelengths greater than a certain value to pass through while blocking light with wavelengths less than that value.

[0151] The present application will be specifically described below through specific embodiments. These embodiments are only some embodiments of the present application and are not intended to limit the present application. Unless otherwise specified, the raw materials used in the following embodiments are all commercially available products.

[0152] Example 1

[0153] A membrane structure includes a substrate and a first membrane group, a second membrane group and a third membrane group sequentially stacked on the substrate. In this embodiment, the first membrane group can have 6 layers, the second membrane group can have 25 layers, and the third membrane group can have 6 layers.

[0154] In this embodiment, the compressive stress material is aluminum silicate, and the tensile stress material is niobium oxide. The membrane structure is prepared using the following steps:

[0155] S100, provides 30mm*30mm PC plastic film;

[0156] S200, depositing the first film group, the second film group and the third film group on a PC plastic film;

[0157] S201. Place the PC plastic film onto the fixture of the sputtering machine and evacuate to 0.005 Pa - 0.01 Pa;

[0158] S202. Argon gas is introduced into the sputtering machine, the rotating frame is turned on, and after the argon gas stabilizes, the ion source is turned on. The working voltage is 1.5kV, the ion beam current is 100mA, the working time is 10min, and the argon gas flow rate is 250sccm. The plastic film surface and the target surface are then cleaned by ion.

[0159] S203. Maintain a continuous argon gas supply, turn on the sputtering power supply of the silicon target and aluminum target, introduce oxygen, with a power of 10kw, an argon gas flow rate of 250sccm, and an oxygen gas flow rate of 55sccm, and deposit an aluminum oxide film on the surface of the plastic film. The coating temperature is 100℃, the vacuum degree is 0.1pa, and the time is 10-120s.

[0160] S204. Maintain a continuous argon gas supply, turn on the sputtering power supply of the niobium target with a power of 10 kW and an argon gas flow rate of 250 sccm, and deposit niobium oxide on the surface of the plastic film. The coating temperature is 100℃, the vacuum degree is 0.1 Pa, and the time is 20-75 s.

[0161] S205. Repeat steps S203 and S204 to achieve the deposition of aluminum silica and niobium oxide.

[0162] The membrane structure in this embodiment is made by sequentially stacking the materials shown in Table 1:

[0163] Table 1

[0164]

[0165]

[0166]

[0167] Example 2:

[0168] A membrane structure is provided. In this embodiment, the first membrane group has 6 layers, the second membrane group has 27 layers, and the third membrane group has 4 layers. In addition, the difference between this embodiment and Embodiment 1 is that the thickness of each sub-membrane in the first membrane group, the second membrane group, and the third membrane group is different.

[0169] The membrane structure in this embodiment is made by sequentially stacking the materials shown in Table 2.

[0170] Table 2

[0171]

[0172]

[0173] Example 3:

[0174] A membrane structure is described in this embodiment, which differs from Embodiment 2 in that the thickness of each sub-membrane within the first, second, and third membrane groups is different. The thickness of each sub-membrane in Embodiment 3 is shown in Table 3.

[0175] Table 3

[0176]

[0177]

[0178] Comparative Example 1:

[0179] One membrane structure differs from Example 1 in that the thickness of the second membrane unit is different. The thickness of each sub-membrane in this comparative example membrane structure is shown in Table 4.

[0180] Table 4

[0181]

[0182]

[0183]

[0184] Comparative Example 2

[0185] A membrane structure includes a substrate and a first membrane group, a second membrane group and a third membrane group sequentially stacked on the substrate. The difference between this comparative example and Example 1 is that the materials of the first membrane group, the second membrane group and the third membrane group are only aluminum silicate.

[0186] The film structure of this comparative example was prepared using the following method:

[0187] S100, provides plastic film;

[0188] S200, depositing a first film group, a second film group, and a third film group on a plastic film;

[0189] S201. Place the plastic film onto the fixture of the sputtering machine and evacuate to 0.005 Pa - 0.01 Pa;

[0190] S202. Argon gas is introduced into the sputtering machine, the rotating frame is turned on, and after the argon gas stabilizes, the ion source is turned on. The working voltage is 1.5kV, the ion beam current is 100mA, the working time is 10min, and the argon gas flow rate is 250sccm. The plastic film surface and the target surface are then cleaned by ion.

[0191] S203. With continuous gas supply, turn on the sputtering power supply of silicon target and aluminum target, introduce oxygen, power of 10kw, argon 250sccm, oxygen 55sccm, deposit aluminum oxide film on the surface of plastic film, coating temperature of 100℃, vacuum degree of 0.1pa, time of 60s.

[0192] S204. Repeat step S203 to achieve the deposition of aluminum silica.

[0193] Comparative Example 3

[0194] A membrane structure includes a substrate and a first membrane group, a second membrane group and a third membrane group sequentially stacked on the substrate. The difference between this comparative example and Example 1 is that the materials of the first membrane group, the second membrane group and the third membrane group are only niobium oxide.

[0195] The film structure of this comparative example was prepared using the following method:

[0196] S100, provides plastic film;

[0197] S200, depositing a first film group, a second film group, and a third film group on a plastic film;

[0198] S201. Place the plastic film onto the fixture of the sputtering machine and evacuate to 0.005 Pa - 0.01 Pa;

[0199] S202. Argon gas is introduced into the sputtering machine, the rotating frame is turned on, and after the argon gas stabilizes, the ion source is turned on. The working voltage is 1.5kV, the ion beam current is 100mA, the working time is 10min, and the argon gas flow rate is 250sccm. The plastic film surface and the target surface are then cleaned by ion.

[0200] S203. With continuous gas supply, turn on the sputtering power supply of the niobium target at a power of 10 kW and an argon gas flow rate of 250 sccm. Deposit niobium oxide on the surface of the plastic film at a coating temperature of 100℃, a vacuum degree of 0.1 Pa, and a time of 75 s.

[0201] S204. Repeat step S203 to achieve niobium oxide deposition.

[0202] Detection methods:

[0203] (1) Stress testing: The thickness of each sub-membrane within the membrane structure was tested using a ZYGO type flatness tester, while referring to the calculation formula:

[0204]

[0205] Among them, E s υ is the elastic modulus of the substrate. s Poisson's ratio of the base material d is the square of the substrate thickness. f Where h is the film thickness, h-h0 is the height difference measured by flatness, and a is the thickness of the film. 2 The area of ​​the thin film;

[0206] According to the above formula, with the same substrate and other parameters, the stress magnitude can be determined by comparing only the height difference.

[0207] (2) The transmittance of the sample samples of the examples and comparative examples was tested using a Cary 500 UV spectrophotometer.

[0208] The test results are shown in Table 5:

[0209] Table 5

[0210]

[0211] Compared with Comparative Example 1, Comparative Example 1 changed the thickness of the second film group, making the thickness of the second film group greater than that of the first film group, but the thickness of the second film group was less than that of the third film group. Comparative Example 1 had a higher transmittance at 800nm, but the color of Comparative Example 1 was yellowish and could not meet the required optical requirements.

[0212] Compared with Comparative Examples 2-3, Example 1 uses an overlapping layer of silicon-aluminum oxide and niobium oxide to form a film structure, while Comparative Example 2 uses only silicon-aluminum oxide, and Comparative Example 3 uses only niobium oxide. According to the test results in Table 5, the height difference in Example 1 is significantly lower than that in Comparative Example 2. Based on the stress detection calculation formula, the stress in Example 1 is much lower than that in Comparative Examples 2-3, thus achieving the preparation of a low-stress film structure. Furthermore, combined with… Figure 3 It can be seen that the film structure of Example 1 has an infrared transmittance of greater than 20% in the wavelength range greater than 800 nm. Combined with... Figure 4-5 It can be seen that the film structure of Comparative Example 2 was severely curled after coating, and the film structure of Comparative Example 3 was also curled after coating, indicating that the residual stress of the film structures of Comparative Examples 2 and 3 was relatively large after coating.

[0213] Compared with Example 1, Example 2 reduced the thickness of the first, second, and third membrane modules, resulting in an overall membrane thickness of 1845 nm. Based on the test results in Table 5, the height difference in Example 2 is slightly greater than that in Example 1. Referring to the stress detection calculation formula, the stress in Example 2 is greater than that in Example 1. Therefore, the stress of the membrane structure is related to its overall thickness. If the thickness is too small, it is not conducive to fabricating a low-stress membrane structure.

[0214] Compared with Example 2, Example 3 increased the thickness of the first, second, and third film groups, resulting in an overall film thickness of 3300 nm. The test results in Table 5 show that the height difference in Example 3 is slightly greater than that in Example 2, but the thickness of Example 3 is also greater, indicating that the coating time is increased and the coating efficiency is reduced.

[0215] The above provides a detailed description of the film structure, its preparation method, and optical device provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A membrane structure, characterized in that, include: Substrate; A first membrane assembly is used to suppress stress changes generated by the substrate, and the first membrane assembly is disposed on the substrate; The second film assembly is used to realize the optical performance of the film structure, and the second film assembly is disposed on the first film assembly; A third membrane assembly is used to suppress stress changes generated by the second membrane assembly, and the third membrane assembly is disposed on the second membrane assembly; The thickness of the second membrane group is greater than the thickness of the first membrane group, and the thickness of the second membrane group is greater than the thickness of the third membrane group.

2. The membrane structure according to claim 1, characterized in that, The ratio of the thickness of the critical membrane of the second membrane group near the first membrane group to the thickness of the critical membrane of the first membrane group near the second membrane group is greater than or equal to 2; and / or The ratio of the thickness of the critical membrane of the second membrane group near the third membrane group to the thickness of the critical membrane of the third membrane group near the second membrane group is greater than or equal to 2.

3. The membrane structure according to claim 1, characterized in that, The thickness of the first membrane assembly ranges from 100 nm to 230 nm; and / or The thickness of the sub-membrane in the first membrane group ranges from 15 nm to 50 nm.

4. The membrane structure according to claim 3, characterized in that, The first membrane assembly includes multiple alternating layers of first and second sub-membranes, wherein the materials of the first and second sub-membranes are different; and / or The thicknesses of the first sub-film and the second sub-film range from 15 nm to 50 nm; and / or The ratio of the thickness of the first sub-membrane to the thickness of the second sub-membrane is 0.5 to 1.

5. The membrane structure according to claim 1, characterized in that, The thickness of the second film assembly ranges from 1845 nm to 3300 nm; and / or The ratio of the thickness of the second membrane assembly to the thickness of the membrane structure is 0.78 to 0.93; and / or The thickness of the sub-membrane of the second membrane group ranges from 40 nm to 185 nm.

6. The membrane structure according to claim 5, characterized in that, The second membrane assembly includes multiple alternating layers of third and fourth sub-membranes, wherein the materials of the third sub-membranes and the fourth sub-membranes are different.

7. The membrane structure according to claim 6, characterized in that, The thickness of the third sub-film ranges from 100 nm to 185 nm; and / or the thickness of the fourth sub-film ranges from 40 nm to 80 nm. Preferably, the ratio of the thickness of the third sub-membrane to the thickness of the fourth sub-membrane is 1.8 to 3.

2.

8. The membrane structure according to claim 1, characterized in that, The thickness of the third membrane assembly ranges from 140 nm to 370 nm; and / or The thickness of the sub-membrane in the third membrane group ranges from 35 nm to 95 nm.

9. The membrane structure according to claim 8, characterized in that, The third membrane assembly includes multiple alternately stacked fifth and sixth sub-membranes, wherein the materials of the fifth sub-membranes are different from those of the sixth sub-membranes; and / or The ratio of the thickness of the fifth sub-membrane to the thickness of the sixth sub-membrane is 1 to 2.

10. The membrane structure according to claim 1, characterized in that, The number of submembranes in the second membrane group is odd; and / or The number of sub-membranes in the first membrane group / third membrane group is even.

11. The membrane structure according to any one of claims 1 to 10, characterized in that, Each sub-membrane in the first membrane group, the second membrane group, and the third membrane group includes a first material or a second material, wherein the first material is a material used to resist the stress of an object that has a compressive tendency; And / or the second material is a material used to resist the tensile stress of an object.

12. The membrane structure according to claim 11, characterized in that, The first material includes at least one of aluminum silicon oxide, silicon oxide, aluminum silicon nitride, and silicon nitride; and / or The second material includes at least one of niobium oxide, chromium oxide, titanium oxide, niobium titanium oxide, chromium titanium oxide, and niobium chromium oxide.

13. The membrane structure according to claim 1, characterized in that, The substrate includes any one of glass, crystal, ceramic, and plastic.

14. The membrane structure according to any one of claims 1, characterized in that, The first membrane assembly, the second membrane assembly, and the third membrane assembly are stacked on one or both sides of the substrate.

15. The membrane structure according to any one of claims 1 to 14, characterized in that, The infrared transmittance of the film structure ranges from 20% to 98% in the wavelength range of 800 nm to 1400 nm.

16. A method for preparing a film structure, characterized in that, The method for preparing the film structure according to any one of claims 1 to 15 comprises the following steps: Provide base materials; A first film assembly is obtained by depositing a film on the substrate; A second membrane assembly is obtained by depositing a film on the first membrane assembly; A third membrane assembly is obtained by depositing a film on the second membrane assembly, thus forming the membrane structure.

17. The preparation method according to claim 16, characterized in that, The first membrane assembly was prepared using the following steps: A first material is deposited on the substrate to obtain a first sub-film; A second material is deposited on the first sub-film to obtain a second sub-film; The first sub-film and the second sub-film are repeatedly deposited to achieve a first film assembly with a preset thickness.

18. The preparation method according to claim 16, characterized in that, The second membrane assembly was prepared using the following steps: A first material is deposited on the first membrane assembly to obtain a third sub-membrane; A second material is deposited on the third sub-film to obtain a fourth sub-film; The third and fourth sub-films are repeatedly deposited to achieve a second film group with a preset thickness.

19. The preparation method according to claim 16, characterized in that, The third membrane assembly was prepared using the following steps: A first material is deposited on the second membrane group to obtain a fifth sub-membrane; A second material is deposited on the fifth sub-film to obtain a sixth sub-film; The fifth and sixth sub-films are repeatedly deposited to achieve a third film group with a preset thickness.

20. An optical device, characterized in that, The membrane structure includes the membrane structure as described in any one of claims 1 to 15 or the membrane structure prepared by the method described in any one of claims 16 to 19.

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