High-hardness scratch-resistant optical lens and method for manufacturing the same

Abstract

The application discloses a kind of high-hardness scratch-resistant optical lenses and preparation method thereof, it is related to optical lens field, including substrate, the substrate surface is sequentially deposited composite hardening antireflection film layer, and sequentially deposited in the composite hardening antireflection film layer of substrate surface.The high-hardness scratch-resistant optical lenses and preparation method thereof of the application greatly improve the overall hardness of film layer, so that nano-hardness can reach more than 18GPa, the structure can effectively resist the deep scratch caused by hard object, ensure that the lens has excellent antireflection effect, the average reflectivity of visible light region can be reduced to about 1%, when plating core strengthening layer, by the process of forming silicon-nitrogen-oxygen mixed material by passing in trace oxygen, effectively reduce the optical absorption possibly caused by film layer over-thickness, help to release the internal stress caused by intermediate core strengthening thick film, so as to enhance the adhesion between the entire composite film layer and substrate and between each film layer.

Description

Technical Field

[0001] This invention relates to the field of optical lenses, and in particular to a high-hardness, scratch-resistant optical lens and its preparation method. Background Technology

[0002] Optical lenses, such as various camera lenses, eyeglass lenses, and sensor protective windows, typically require an anti-reflective coating. The core function of this coating is to reduce light reflection loss at the lens surface, increase the transmittance of the optical system, and suppress stray light, thereby improving image quality and clarity. Currently, the industry commonly uses dielectric materials such as silicon nitride (SiNx) and silicon dioxide (SiO2) to deposit multiple layers of anti-reflective coatings through alternating stacking. This conventional anti-reflective coating typically consists of 5 to 11 layers, with a total thickness controlled between 300 and 800 nanometers. While achieving good anti-reflective effects, it also enhances the surface hardness of the lens to a certain extent.

[0003] As the application scenarios of optical devices continue to expand, especially in harsh environments such as outdoor sports, automotive lenses, and mobile device cameras, which are susceptible to friction, scratches, or dust impacts, the requirements for the mechanical properties of lens surfaces are increasing. Conventional anti-reflective coatings, due to their thin overall thickness and lack of a reinforcing layer specifically designed to resist mechanical damage, have limited surface hardness and abrasion resistance. When the lens surface comes into contact with hard objects such as quartz sand or metal shavings, it is prone to deep scratches. These scratches severely scatter light, leading to blurred images, reduced contrast, and directly affecting the reliability and lifespan of the end product.

[0004] To address the scratch resistance issue, existing technologies primarily involve hardening existing antireflective coating systems. However, these improvements are often limited to adjusting the material ratios or fine-tuning the thickness of individual layers, without fundamentally altering the overall structure of the coating. This leads to a technical contradiction: simply increasing the thickness of hard coating layers (such as silicon nitride) to improve hardness often introduces excessive internal stress, affecting the adhesion between the coating and the substrate, and even causing cracking or detachment. Simultaneously, excessively thick hard coating layers may increase optical absorption and reduce light transmittance. Therefore, significantly improving the surface hardness, abrasion resistance, and deep scratch resistance of optical lenses while maintaining excellent antireflective performance and optical transmittance has become a pressing technical challenge in this field. Summary of the Invention

[0005] The main objective of this invention is to provide a high-hardness, scratch-resistant optical lens and its preparation method, which can effectively solve the technical problems raised in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A high-hardness, scratch-resistant optical lens includes a substrate. A composite hardening antireflective film layer is sequentially deposited on the surface of the substrate, and another composite hardening antireflective film layer is sequentially deposited on the surface of the substrate. The composite hardening antireflective film layer is prepared using reactive magnetron sputtering. The film layer uses a material system including silicon nitride, silicon dioxide, and a silicon-nitrogen-oxygen mixture, and is partitioned according to specific functions and structures, specifically divided into three functional parts:

[0008] The first transition and antireflection section is directly deposited on the substrate surface and consists of alternating layers of SiNx and SiO2 films, with fewer than 11 layers and a total thickness of less than 1000 nanometers.

[0009] The second core reinforcement part is deposited on the surface of the first part, and its main components are one or more thick silicon nitride or silicon oxynitride film layers with a total thickness ranging from 800 nanometers to 5000 nanometers.

[0010] The third surface hardening and antireflection section is deposited on the surface of the second section and consists of alternating layers of SiNx and SiO2 films, with fewer than 11 layers and a total thickness of less than 1000 nanometers.

[0011] Preferably, when depositing the silicon nitride film layer of the second core reinforcement portion, a small amount of oxygen in the range of 0 to 100 sccm is introduced into the reaction gas to form a silicon-nitrogen-oxygen mixed material.

[0012] Preferably, the substrate is made of a material selected from glass, plastic, silicon wafers, and sapphire glass.

[0013] Preferably, the lens is resistant to scratches of Mohs hardness 7 and higher, and the average reflectivity of the visible light region of the lens is not higher than 1%.

[0014] Preferably, the composite hardened antireflective film layer comprises the following 17 layers from the substrate upwards:

[0015] Layer 1: Silicon dioxide, 30nm thick;

[0016] The second layer is silicon nitride, with a thickness of 13.94 nm.

[0017] The third layer: silicon dioxide, with a thickness of 45.91 nm;

[0018] 4th layer: Silicon nitride, with a thickness of 36.25nm;

[0019] 5th layer: silicon dioxide, with a thickness of 15.72nm;

[0020] 6th layer: silicon nitride oxygen, with a thickness of 537.24nm;

[0021] 7th layer: silicon dioxide, with a thickness of 18.48nm;

[0022] 8th layer: Silicon nitride, with a thickness of 38.43nm;

[0023] 9th layer: Silicon dioxide, with a thickness of 50.02nm;

[0024] Layer 10: Silicon nitride, with a thickness of 32.64 nm;

[0025] 11th layer: Silicon dioxide, with a thickness of 32.24nm;

[0026] Layer 12: Silicon nitride, with a thickness of 172.35nm;

[0027] Layer 13: Silicon dioxide, with a thickness of 7.09 nm;

[0028] Layer 14: Silicon nitride oxygen, with a thickness of 811.89nm;

[0029] 15th layer: Silicon dioxide, with a thickness of 9.58nm;

[0030] Layer 16: Silicon nitride, with a thickness of 149.18 nm;

[0031] Layer 17: Silicon dioxide, with a thickness of 87.77 nm.

[0032] A method for preparing a high-hardness, scratch-resistant optical lens, employing reactive magnetron sputtering, includes the following steps:

[0033] S1. Substrate cleaning and loading: The optical lens substrate is cleaned and dried, and then loaded into the cavity of the magnetron sputtering coating equipment;

[0034] S2. Vacuum preparation: Evacuate the cavity to a high vacuum state;

[0035] S3. Reactive magnetron sputtering coating: Under the high vacuum state, argon gas is introduced into the cavity as the working gas, and silicon atom flow is generated by bombarding the silicon target with argon ions, and the workpiece holding the substrate is kept rotating in the cavity; by precisely controlling the type and flow rate of the gas introduced into the reaction area, the silicon atom flow reacts with the reactive gas on the substrate surface and deposits a film layer.

[0036] S4. Film sequence control: By controlling the introduction time of each reactive gas or the residence time of the substrate under each reaction area, the first transition and antireflection portion, the second core reinforcement portion and the third surface hardening and antireflection portion of the composite hardened antireflection film as described in claim 1 are deposited sequentially to complete the deposition of the entire composite film system.

[0037] Preferably, in step S2, the high vacuum state is a vacuum degree better than 2.0 × 10^-3 Pa.

[0038] Preferably, in step S3, different film materials are deposited by precisely controlling the type and flow rate of the introduced reactive gas, specifically including:

[0039] Nitrogen gas is introduced to generate a silicon nitride film;

[0040] Oxygen is introduced to generate a silicon dioxide film;

[0041] Nitrogen and oxygen are simultaneously introduced to generate a silicon-nitrogen-oxygen hybrid material film.

[0042] Preferably, in step S4, when depositing the film layer of the second core reinforcement portion, nitrogen gas and oxygen gas with a flow rate of 0 to 100 sccm are simultaneously introduced into the reaction area to generate a silicon-nitrogen-oxygen mixed material.

[0043] The beneficial effects that can be achieved by the above embodiments of the present invention include: by introducing a second core reinforcing part with a thickness significantly greater than that of a conventional film layer, ranging from 800 to 5000 nanometers, and optimizing its silicon nitride or silicon nitride oxygen material and preparation process, the overall hardness of the film layer is greatly improved, so that the nanohardness can reach more than 18 GPa. This structure can effectively resist deep scratches caused by hard objects, reaching a Mohs hardness of 7 or higher. At the same time, the outermost third part further enhances the mechanical strength and density of the surface, significantly improving the abrasion resistance of the lens.

[0044] Through the meticulous film design of the first transition and anti-reflection section and the outermost surface hardening and anti-reflection section, the lens has excellent anti-reflection effect, and the average reflectivity in the visible light area can be reduced to about 1%. When depositing the core reinforcement layer, the process of introducing a trace amount of oxygen to form a silicon-nitrogen-oxygen mixed material effectively reduces the optical absorption that may be caused by excessive film thickness. Thus, while obtaining ultra-high hardness, the overall high transmittance of the lens is guaranteed, and the loss of optical performance is minimal.

[0045] The design of the first transition and anti-reflection section not only optimizes optical performance, but also acts as a stress buffer layer, which helps to release the internal stress brought by the central core reinforcement thick film, thereby enhancing the adhesion between the entire composite film layer and the substrate, as well as between each film layer, and improving the film layer's firmness, durability, and long-term reliability of the product.

[0046] Based on mature reactive magnetron sputtering technology, complex three-layer functional partitioned film structures can be achieved by precisely controlling the type and flow rate of reactive gases and the coating time. The preparation method has clear process parameters, good repeatability, and high production efficiency, making it very suitable for large-scale industrial production. Attached Figure Description

[0047] Figure 1 This is a flowchart of a method for preparing a high-hardness, scratch-resistant optical lens according to the present invention;

[0048] Figure 2 This is a structural diagram of the film stacking design for a high-hardness, scratch-resistant optical lens according to the present invention;

[0049] Figure 3 This is a reflection spectrum curve of a high-hardness, scratch-resistant optical lens according to the present invention;

[0050] Figure 4 This is a nano-indentation hardness diagram of a high-hardness, scratch-resistant optical lens according to the present invention. Detailed Implementation

[0051] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0052] A high-hardness, scratch-resistant optical lens includes a substrate. A composite hardening antireflective film layer is sequentially deposited on the surface of the substrate, and another composite hardening antireflective film layer is sequentially deposited on the substrate surface. The composite hardening antireflective film layer is prepared using reactive magnetron sputtering. The film layer employs a material system including silicon nitride (SiNx), silicon dioxide (SiO2), and a silicon-oxygen nitride (SiOxNy) mixture, and is partitioned according to specific functions and structures, specifically divided into three functional parts:

[0053] The first transition and antireflection section is directly deposited on the substrate surface and consists of alternating layers of SiNx and SiO2 films, with fewer than 11 layers and a total thickness of less than 1000 nanometers.

[0054] The second core reinforcement part is deposited on the surface of the first part, and its main components are one or more thick silicon nitride (SiNx) or silicon nitride (SiOxNy) films with a total thickness ranging from 800 nanometers to 5000 nanometers.

[0055] The third surface hardening and antireflection section is deposited on the surface of the second section and consists of alternating layers of SiNx and SiO2 films, with fewer than 11 layers and a total thickness of less than 1000 nanometers.

[0056] In this embodiment, when depositing the silicon nitride (SiNx) film layer of the second core reinforcement portion, a small amount of oxygen in the range of 0 to 100 sccm is introduced into the reaction gas to form a silicon nitride oxygen (SiOxNy) mixed material.

[0057] In this embodiment, the substrate material is selected from glass, plastic, silicon wafer and sapphire glass.

[0058] In this embodiment, the lens can resist scratches of Mohs hardness level 7 and higher, and the average reflectivity of the visible light area of ​​the lens is not higher than 1%.

[0059] In this embodiment, the composite hardened antireflective film layer comprises the following 17 layers from the substrate upwards:

[0060] Layer 1: Silicon dioxide, 30nm thick;

[0061] The second layer is silicon nitride, with a thickness of 13.94 nm.

[0062] The third layer: silicon dioxide, with a thickness of 45.91 nm;

[0063] 4th layer: Silicon nitride, with a thickness of 36.25nm;

[0064] 5th layer: silicon dioxide, with a thickness of 15.72nm;

[0065] 6th layer: silicon nitride oxygen, with a thickness of 537.24nm;

[0066] 7th layer: silicon dioxide, with a thickness of 18.48nm;

[0067] 8th layer: Silicon nitride, with a thickness of 38.43nm;

[0068] 9th layer: Silicon dioxide, with a thickness of 50.02nm;

[0069] Layer 10: Silicon nitride, with a thickness of 32.64 nm;

[0070] 11th layer: Silicon dioxide, with a thickness of 32.24nm;

[0071] Layer 12: Silicon nitride, with a thickness of 172.35nm;

[0072] Layer 13: Silicon dioxide, with a thickness of 7.09 nm;

[0073] Layer 14: Silicon nitride oxygen, with a thickness of 811.89nm;

[0074] 15th layer: Silicon dioxide, with a thickness of 9.58nm;

[0075] Layer 16: Silicon nitride, with a thickness of 149.18 nm;

[0076] Layer 17: Silicon dioxide, with a thickness of 87.77 nm.

[0077] like Figure 1 As shown, a method for preparing a high-hardness, scratch-resistant optical lens employs reactive magnetron sputtering and includes the following steps:

[0078] S1. Substrate cleaning and loading: The optical lens substrate is cleaned and dried, and then loaded into the cavity of the magnetron sputtering coating equipment;

[0079] S2. Vacuum preparation: Evacuate the cavity to a high vacuum state;

[0080] S3. Reactive magnetron sputtering coating: Under the high vacuum state, argon gas is introduced into the cavity as the working gas, and silicon atom flow is generated by bombarding the silicon target with argon ions, and the workpiece holding the substrate is kept rotating in the cavity; by precisely controlling the type and flow rate of the gas introduced into the reaction area, the silicon atom flow reacts with the reactive gas on the substrate surface and deposits a film layer.

[0081] S4. Film sequence control: By controlling the introduction time of each reactive gas or the residence time of the substrate under each reaction area, the first transition and antireflection portion, the second core reinforcement portion and the third surface hardening and antireflection portion of the composite hardened antireflection film as described in claim 1 are deposited sequentially to complete the deposition of the entire composite film system.

[0082] In this embodiment, in step S2, the high vacuum state is a vacuum degree better than 2.0 × 10^-3 Pa.

[0083] In this embodiment, step S3, which involves precisely controlling the type and flow rate of the introduced reactive gas to deposit different film materials, specifically includes:

[0084] Nitrogen gas is introduced to generate a silicon nitride film;

[0085] Oxygen is introduced to generate a silicon dioxide film;

[0086] Nitrogen and oxygen are simultaneously introduced to generate a silicon-nitrogen-oxygen hybrid material film.

[0087] In this embodiment, in step S4, when depositing the film layer of the second core reinforcement portion, nitrogen gas and oxygen gas with a flow rate of 0 to 100 sccm are simultaneously introduced into the reaction area to generate a silicon-nitrogen-oxygen mixed material.

[0088] Specifically, silicon nitride has high hardness and a mature coating process. Increasing the thickness of silicon nitride can improve the overall hardness of the film and increase its scratch resistance. Through a three-part film stacking design, the adhesion between the main thickness of the silicon nitride layer and the substrate is not reduced, and the wear resistance of the outer surface is not reduced. By optimizing the sputtering target gas parameters, the overall stress of the film layer is reduced. By optimizing the sputtering reaction gas parameters, the overall absorption rate of the film layer is reduced. By adjusting the thickness of the silicon nitride layer in the middle second part of the film system, the overall hardness performance of the film against nanoindentation can be adjusted. By adjusting the thickness of the film layer in the middle third part of the film system, the hardness value of different depths of nanoindentation can be adjusted.

[0089] In the embodiments provided by this invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and other division methods may exist in actual implementation. Modules described as separate components may or may not be physically separated, and components shown as modules may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the method in this embodiment according to actual needs.

[0090] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A high-hardness, scratch-resistant optical lens, comprising a substrate, wherein a composite hardening antireflection film layer is sequentially deposited on the surface of the substrate, and a composite hardening antireflection film layer is sequentially deposited on the surface of the substrate, wherein the composite hardening antireflection film layer is prepared by reactive magnetron sputtering, characterized in that: The film layer adopts a material system including silicon nitride, silicon dioxide, and silicon-nitrogen-oxygen mixed materials, and is designed in sections according to specific functions and structures, specifically divided into three functional parts: The first transition and antireflection section is directly deposited on the substrate surface and consists of alternating layers of SiNx and SiO2 films, with fewer than 11 layers and a total thickness of less than 1000 nanometers. The second core reinforcement part is deposited on the surface of the first part, and its main components are one or more thick silicon nitride or silicon oxynitride film layers with a total thickness ranging from 800 nanometers to 5000 nanometers. The third surface hardening and antireflection section is deposited on the surface of the second section and consists of alternating layers of SiNx and SiO2 films, with fewer than 11 layers and a total thickness of less than 1000 nanometers.

2. The high-hardness, scratch-resistant optical lens according to claim 1, characterized in that: When depositing the silicon nitride film layer of the second core reinforcement part, a small amount of oxygen in the range of 0 to 100 sccm is introduced into the reaction gas to form a silicon-nitrogen-oxygen mixed material.

3. The high-hardness, scratch-resistant optical lens according to claim 1, characterized in that: The substrate is made of a material selected from glass, plastic, silicon wafers, and sapphire glass.

4. The high-hardness, scratch-resistant optical lens according to claim 1, characterized in that: The lens can resist scratches of Mohs hardness 7 and higher, and the average reflectivity of the visible light area of ​​the lens is no higher than 1%.

5. The high-hardness, scratch-resistant optical lens according to claim 1, characterized in that: The composite hardened antireflective film layer comprises the following 17 layers from the substrate upwards: Layer 1: Silicon dioxide, 30nm thick; The second layer is silicon nitride, with a thickness of 13.94 nm. The third layer: silicon dioxide, with a thickness of 45.91 nm; 4th layer: Silicon nitride, with a thickness of 36.25nm; 5th layer: silicon dioxide, with a thickness of 15.72nm; 6th layer: silicon nitride oxygen, with a thickness of 537.24nm; 7th layer: silicon dioxide, with a thickness of 18.48nm; 8th layer: Silicon nitride, with a thickness of 38.43nm; 9th layer: Silicon dioxide, with a thickness of 50.02nm; Layer 10: Silicon nitride, with a thickness of 32.64 nm; 11th layer: Silicon dioxide, with a thickness of 32.24nm; Layer 12: Silicon nitride, with a thickness of 172.35nm; Layer 13: Silicon dioxide, with a thickness of 7.09 nm; Layer 14: Silicon nitride oxygen, with a thickness of 811.89nm; 15th layer: Silicon dioxide, with a thickness of 9.58nm; Layer 16: Silicon nitride, with a thickness of 149.18 nm; Layer 17: Silicon dioxide, with a thickness of 87.77 nm.

6. A method for preparing a high-hardness, scratch-resistant optical lens according to any one of claims 1-5, characterized in that, The reactive magnetron sputtering process includes the following steps: S1. Substrate cleaning and loading: The optical lens substrate is cleaned and dried, and then loaded into the cavity of the magnetron sputtering coating equipment; S2. Vacuum preparation: Evacuate the cavity to a high vacuum state; S3. Reactive magnetron sputtering coating: Under the high vacuum state, argon gas is introduced into the cavity as the working gas, and silicon atom flow is generated by bombarding the silicon target with argon ions, and the workpiece holding the substrate is kept rotating in the cavity; by precisely controlling the type and flow rate of the gas introduced into the reaction area, the silicon atom flow reacts with the reactive gas on the substrate surface and deposits a film layer. S4. Film sequence control: By controlling the introduction time of each reactive gas or the residence time of the substrate under each reaction area, the first transition and antireflection portion, the second core reinforcement portion and the third surface hardening and antireflection portion of the composite hardened antireflection film as described in claim 1 are deposited sequentially to complete the deposition of the entire composite film system.

7. The method for preparing a high-hardness, scratch-resistant optical lens according to claim 6, characterized in that: In step S2, the high vacuum state is a vacuum degree better than 2.0×10^-3 Pa.

8. The method for preparing a high-hardness, scratch-resistant optical lens according to claim 3, characterized in that: In step S3, different film materials are deposited by precisely controlling the type and flow rate of the introduced reactive gas, specifically including: Nitrogen gas is introduced to generate a silicon nitride film; Oxygen is introduced to generate a silicon dioxide film; Nitrogen and oxygen are simultaneously introduced to generate a silicon-nitrogen-oxygen hybrid material film.

9. The method for preparing a high-hardness, scratch-resistant optical lens according to claim 6, characterized in that: In step S4, when depositing the film layer of the second core reinforcement portion, nitrogen gas and oxygen gas with a flow rate of 0 to 100 sccm are simultaneously introduced into the reaction area to generate a silicon-nitrogen-oxygen mixed material.

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