Method for producing spherical conductive films and electrodes on optical glass substrates

Abstract

The present application belongs to the technical field of photoelectric product processing, and particularly relates to a preparation method of a spherical conductive film and an electrode of an optical glass substrate, comprising the following steps: S1, cleaning treatment of the optical glass; S2, placing the optical glass on a film plating tool, and using a film plating machine to evaporate an ITO conductive film; S3, testing the transmittance of the optical glass after film plating; S4, placing the optical glass on an electrode plating tool, and first evaporating a NiCr bottom film on the electrode plating position of the optical glass, and then plating a Cu electrode; and S5, testing the conductivity of the optical glass after electrode plating. The inner diameter surface arc radius SR of the middle spherical bulge of the electrode plating tool is 24.85 mm, and the outer diameter surface arc radius SR is 27.8 mm, so that a gap of ≤0.2 mm between the convex surface of the optical glass and the concave surface of the spherical bulge is ensured. The plating method improves the preparation efficiency, spectral performance and wear resistance of the spherical conductive film and the electrode, and solves the problems of poor firmness and easy falling of the Cu electrode.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photoelectric product processing, and particularly relates to a preparation method of a spherical conductive film and an electrode of an optical glass substrate. BACKGROUND

[0002] With the development of the full airspace of military photoelectric technology, the application of all-weather photoelectric products is more and more, especially in low-temperature environments, in order to reduce the influence of bad weather such as frost and fog, it is required that the ocular group in the photoelectric system should have the effect of defrosting and defogging, and the all-weather and multi-territory observation capability of the military photoelectric product is improved. The transparent conductive film is a new type of photoelectric film, which combines the optical transparency and the conductivity together, has good transmittance in the visible spectrum range, low resistivity, good wear resistance and chemical stability, and is therefore widely applied to the anti-fog and anti-frost film of the ocular glass of the photoelectric system of the military armored vehicle, tank and other military equipment. Since the conductive film is plated on the spherical surface, due to the effect of the tensile stress, the plated film is not firm enough, and the metal electrode needs to be plated with a curved surface pattern, and the acquisition and firmness of the electrode pattern also have problems. SUMMARY

[0003] In view of the above problems, the application provides a preparation method of a spherical conductive film and an electrode of an optical glass substrate, which solves the influence of the plating process and the plating tooling on the spectral performance, firmness and wear resistance of the conductive film and the electrode.

[0004] In order to achieve the above purpose, the application adopts the following technical scheme:

[0005] The preparation method of the spherical conductive film and the electrode of the optical glass substrate comprises the following steps:

[0006] S1, the optical glass is cleaned and wiped to ensure the cleanliness of the optical glass substrate; the optical glass is a spherical glass;

[0007] S2, the optical glass is placed on the plating tooling, and the convex surface of the optical glass is placed in the plating hole of the plating tooling; the plating tooling is placed in the plating machine together with the optical glass to plate the conductive film, the ITO conductive film is plated on the optical glass substrate by evaporation, and baking and drying are performed;

[0008] S3, the optical glass after plating is subjected to transmittance inspection; the optical glass with qualified transmittance is screened out;

[0009] S4, the optical glass with qualified transmittance is placed on the electrode plating tooling, and the electrode plating tooling is placed in the plating machine together with the optical glass; the NiCr bottom film is plated on the electrode plating position of the optical glass by evaporation, and then the Cu electrode is plated, and baking and drying are performed;

[0010] S5, conductive property inspection of the optical glass after plating the electrode; detecting the resistance value of the Cu electrode of the optical glass.

[0011] Further, the environment for plating the conductive film and the electrode on the optical glass requires temperature of 18-26℃, relative humidity of 30-70%, and environment cleanliness of 10,000.

[0012] Further, the cleaning and wiping of the optical glass in S1 is performed by using degreasing cotton cloth to dip cleaning agent.

[0013] Further, the plating tool in S2 is of a planar circular ring structure, and a plating hole is formed in the center of the plating tool, which is a circular through hole.

[0014] Further, the evaporation rate of the evaporation material for the ITO conductive film in S2 is 0.4-0.6 nm / s; and the baking temperature is 380℃, and a higher baking temperature can improve the transmittance of the ITO conductive film.

[0015] Further, the plating tool in S4 is fixed with a spherical bulge matching the optical glass in the center of the circular through hole of the plating tool, and two plating electrode holes are symmetrically formed in the edge of the spherical bulge for exposing the plating electrode position, and the plating electrode hole is designed according to the required electrode pattern, and is preferably an arc-shaped long hole.

[0016] Further, when the optical glass is placed on the plating tool in S4, the concave surface of the spherical bulge of the plating tool faces upward, and the convex surface (i.e. the conductive film surface) of the optical glass faces downward and is placed in the concave surface of the spherical bulge, and the inner diameter surface radius SR of the spherical bulge is 24.85 mm, and the outer diameter surface radius SR is 27.8 mm, so as to ensure that the convex surface of the optical glass and the concave surface of the spherical bulge do not contact each other, and the gap therebetween is not greater than 0.2 mm.

[0017] Further, the evaporation rate of the NiCr is 0.5-1.5 nm / s, and the evaporation rate of the Cu is 2-10 nm / s; and the baking temperature is 80℃, and the film thickness of the NiCr bottom film and the Cu electrode obtained by plating at this temperature has relatively good strength and stability.

[0018] Further, the plating machine in S2 and S4 is an electron beam vacuum plating machine, and a workpiece disc is arranged in the plating machine, and a plurality of workpiece ports are arranged on the workpiece disc, and the plating tool and the plating electrode tool are respectively placed in the corresponding workpiece ports.

[0019] The present invention also includes other components that enable its normal use, all of which are conventional means in the art. In addition, any devices or components not limited in the present invention adopt the prior art in the art.

[0020] The beneficial effects of this invention are as follows:

[0021] The present invention provides a method for preparing spherical conductive films and electrodes on optical glass substrates. The method is simple and easy to operate. By designing fixtures for depositing spherical conductive films and electrodes, the preparation efficiency of spherical conductive films and electrodes is improved, and the preparation of spherical conductive film and electrode patterns is enhanced. The method solves the problems of the coating process and fixture affecting the spectral performance, adhesion, and abrasion resistance of the conductive film and electrodes, and improves the ability of optical glass coatings to withstand constant humidity and heat, and low-temperature smoke environments. It also solves the problems of poor density, insufficient strength, poor adhesion, and easy detachment of copper electrode films. This preparation method has significant application value for the deposition of spherical conductive films and electrodes on optical glass and can be widely used in the processing of various visible light optical instruments, and can be applied to military and civilian products in aerospace, aviation, and shipbuilding industries. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the fabrication method of the spherical conductive film and electrode on the optical glass substrate in this embodiment.

[0023] Figure 2 This is a table of process parameters for the environmental requirements of depositing conductive films and electrodes on optical glass in the embodiments.

[0024] Figure 3 This is a schematic diagram of the front view structure of the optical glass in the embodiment.

[0025] Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure of the optical glass along the CC direction.

[0026] Figure 5 This is a schematic diagram of the main structure of the coating fixture in the embodiment.

[0027] Figure 6 for Figure 5 A cross-sectional view of the coating fixture along the AA direction.

[0028] Figure 7 This is a schematic diagram of the front view structure of the electrode plating fixture in the embodiment.

[0029] Figure 8 for Figure 7 A cross-sectional view of the electrode plating fixture along the BB direction. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] Example

[0032] like Figure 1 As shown, the method for fabricating the spherical conductive film and electrode on an optical glass substrate includes the following steps:

[0033] S1. Clean the optical glass to ensure the cleanliness of the optical glass substrate 1; the cleaning process involves using a degreased cotton cloth soaked in a cleaning agent to clean and wipe the optical glass, wherein the cleaning agent is anhydrous ethanol. Figures 3-4 As shown, the optical glass is spherical glass; before the conductive film and electrodes are deposited on the optical glass, an antireflection film 2 is pre-deposited on the concave surface of the spherical glass. The specific setting of the antireflection film is the same as that of the antireflection film and its preparation method disclosed in patent document CN115433906A, and will not be repeated here.

[0034] S2. Place the optical glass onto the coating fixture, with the convex surface of the optical glass positioned within the coating hole of the coating fixture; as follows. Figures 5-6 As shown, the coating fixture 6 has a planar annular structure, with a coating hole 7 at its center. The coating hole is a circular through hole. The coating fixture, together with the optical glass, is placed in the coating machine for conductive film deposition. An ITO conductive film 3 is deposited on the optical glass substrate by vapor deposition and then baked and dried. The vapor deposition material used for the ITO conductive film is In2O3+SnO, with an evaporation rate of 0.4–0.6 nm / s. The baking temperature is 380℃, and the higher baking temperature can improve the transmittance of the ITO conductive film.

[0035] Secondly, since the conductive film and electrodes are plated on a curved surface, tensile stress will be generated, which will affect the adhesion of the film and electrodes. By using a high-temperature coating at 380℃ on the substrate and appropriately increasing the evaporation rate, the hardness, adhesion and density of the ITO film can be greatly improved.

[0036] like Figure 2 As shown, the environmental requirements for depositing conductive films and electrodes on optical glass are a temperature of 18–26°C, a relative humidity of 30–70%, and an environmental cleanliness level of 10,000. Changes in ambient temperature and humidity can cause changes in the substrate, and poor cleanliness can lead to a decrease in the surface defect level of the parts. Therefore, environmental requirements are quite important for the deposition of ITO films and metal electrode films.

[0037] The coating machine is an electron beam vacuum coating machine. Inside the machine is a workpiece tray with several workpiece openings. The coating fixture and the electrode fixture are each placed in their respective workpiece openings. The specific setup of the coating machine is the same as that disclosed in patent document CN208829752U, and will not be repeated here.

[0038] S3. Test the transmittance of the coated optical glass; screen out the optical glass with qualified transmittance; the transmittance in the 450nm~700nm band reaches more than 88%.

[0039] S4. Place the optical glass with acceptable transmittance onto the electrode plating fixture, and then place the electrode plating fixture together with the optical glass into the coating machine; Figures 7-8 As shown, the electrode plating fixture is based on the film plating fixture, with a spherical bulge 8 matching the optical glass fixedly embedded in the center of its circular through-hole. Two electrode plating holes, symmetrically formed on the edge of the spherical bulge, are used to expose the electrode plating position; these electrode plating holes are arc-shaped elongated holes 9. A NiCr base film 4 is first deposited on the electrode plating position of the optical glass using a vapor deposition method, followed by the deposition of a Cu electrode 5, and then baked and dried. The NiCr evaporation rate is 0.5–1.5 nm / s, and the Cu evaporation rate is 2–10 nm / s. A suitable evaporation rate can improve the density of the film and reduce defects; too slow a rate can easily result in insufficient film density, while too fast a rate can easily cause defects in the film. A baking temperature of 80℃ results in relatively good strength and stability of the NiCr base film and Cu electrode film thickness. NiCr has better adhesion and firmness, effectively solving the problem of poor adhesion and easy detachment of Cu electrodes compared to the traditional method of directly plating copper.

[0040] When placing the optical glass onto the electrode plating fixture, the concave side of the spherical bulge of the electrode plating fixture faces upward, and the convex side of the optical glass faces downward, placed inside the concave side of the spherical bulge. The inner diameter radius SR of the spherical bulge is 24.85 mm, and the outer diameter radius SR is 27.8 mm, ensuring that the convex side of the optical glass and the concave side of the spherical bulge do not contact each other, and the gap between them is no greater than 0.2 mm.

[0041] Because the electrode pattern is narrow, a 135° chamfer is applied to the lower edge of the electrode deposition fixture to improve the deposition efficiency of the metal film. This ensures that the surface finish of the optical glass is not compromised and that the coating is applied only to the electrode pattern area.

[0042] Because optical glass is relatively soft, to prevent the conductive film from rubbing and developing "streaks" and "marks," the gap angle between the convex surface and the concave surface of the spherical surface should be minimized as much as possible. This prevents the film from splashing into non-working areas and causing a "virtual surface" phenomenon. The conductive film and electrodes of the optical glass must be plated on a spherical shape with a certain curvature and arc. The electrode pattern must be plated in a designated area, and it is not allowed to appear in other areas to avoid parts failing to meet the requirements and being scrapped.

[0043] S5. Conduct conductivity test on the optical glass after electrode plating; that is, test the resistance value of the Cu electrode of the optical glass. If the resistance value measurement result meets the standard, the finished optical glass with electrode plating is obtained.

[0044] The technical solutions of the present invention are not limited to the specific embodiments described above. Without departing from the scope and spirit of the described embodiments, many modifications and changes will be obvious to those skilled in the art. Any technical modifications made within the spirit and principles of the present invention will fall within the protection scope of the present invention.

Claims

1. A method for fabricating a spherical conductive film and electrode on an optical glass substrate, comprising the following steps: S1. The optical glass is cleaned to ensure the cleanliness of the optical glass substrate; the optical glass is spherical glass. S2. Place the optical glass onto the coating fixture, with the convex surface of the optical glass placed inside the coating hole of the coating fixture; place the coating fixture together with the optical glass into the coating machine for conductive film deposition, deposit an ITO conductive film on the optical glass substrate by vapor deposition, and then bake and dry it. The coating fixture has a planar annular structure, and a coating hole is opened in the center of the coating fixture. The coating hole is a circular through hole. S3. Test the transmittance of the coated optical glass; screen out the optical glass with qualified transmittance. S4. Place the optical glass with qualified transmittance onto the electrode plating fixture, and then place the electrode plating fixture together with the optical glass into the coating machine. A NiCr base film is first deposited on the electrode deposition site of the optical glass by vapor deposition, followed by the deposition of Cu electrode, and then baked and dried. The electrode plating fixture, based on the coating fixture, has a spherical bulge that matches the optical glass, which is fixedly embedded in the center of the circular through hole. The spherical bulge also has two symmetrical electrode plating holes on its edge for exposing the electrode plating position. S5. Conduct conductivity tests on the optical glass after electrode plating; detect the resistance value of the Cu electrode in the optical glass.

2. The method for preparing the spherical conductive film and electrode on the optical glass substrate according to claim 1, characterized in that: The environmental requirements for depositing conductive films and electrodes on optical glass are a temperature of 18–26°C, a relative humidity of 30–70%, and an environmental cleanliness level of 10,000.

3. The method for preparing the spherical conductive film and electrode on the optical glass substrate according to claim 1, characterized in that: The cleaning process in S1 involves using a degreased cotton cloth soaked in a cleaning agent to clean and wipe the optical glass. The cleaning agent used is anhydrous ethanol.

4. The method for preparing the spherical conductive film and electrode on the optical glass substrate according to claim 1, characterized in that: The ITO conductive film in S2 uses In2O3+SnO as the vapor deposition material, with an evaporation rate of 0.4~0.6nm / s and a baking temperature of 380℃.

5. The method for preparing the spherical conductive film and electrode on an optical glass substrate according to claim 1, characterized in that: When placing the optical glass onto the electrode plating fixture in S4, the concave side of the spherical bulge of the electrode plating fixture faces upward, and the convex side of the optical glass faces downward, placed inside the concave side of the spherical bulge. The inner diameter radius of the spherical bulge is SR=24.85mm, and the outer diameter radius of the spherical bulge is SR=27.8mm, ensuring that the convex side of the optical glass and the concave side of the spherical bulge do not contact each other, and the gap between them is ≤0.2mm.

6. The method for preparing the spherical conductive film and electrode on the optical glass substrate according to claim 1, characterized in that: The evaporation rate of NiCr in S4 is 0.5–1.5 nm / s, and the evaporation rate of Cu is 2–10 nm / s; the baking temperature is 80℃.

7. The method for preparing the spherical conductive film and electrode on an optical glass substrate according to claim 1, characterized in that: The coating machine described in S2 and S4 is an electron beam vacuum coating machine. The coating machine is equipped with a workpiece tray with several workpiece openings. The coating fixture and the electrode plating fixture are placed in their respective workpiece openings.

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