Method for preparing etching solution, photovoltaic printing screen plate and etching preparation method thereof

Abstract

The application discloses a preparation method of an etching solution, a photovoltaic printing screen and an etching preparation method thereof. The preparation method of the etching solution comprises the following steps: mixing deionized water and tallow alkyl propylene diamine under a preset stirring condition, and stirring until a uniform state is obtained to obtain a target solvent; sequentially adding nitric acid, hydrofluoric acid and phosphoric acid into the target solvent in a first preset mode to obtain a first solution; adding at least one corrosion-resistant additive into the first solution in a second preset mode to obtain a second solution; and adding a crystal lattice refiner into the second solution in a third preset mode to obtain the etching solution. The technical scheme can guarantee that the thinned screen plate has high-precision surface quality, and guarantee that the thinned screen plate has refined metal crystal lattice size, fully plays the material advantages of stainless steel such as 304 stainless steel, and improves the tensile strength, corrosion resistance and service life of the screen plate.

Description

Technical Field

[0001] This application relates to the field of photovoltaic module manufacturing technology, and in particular to a method for preparing an etching solution, a photovoltaic printing screen and its etching preparation method. Background Technology

[0002] Photovoltaic printing screens are the core consumables for printing electrodes on solar cells. Their thickness accuracy, surface roughness, etching uniformity, metal lattice structure, and substrate properties directly affect the linewidth control, conductivity, and lifespan of the printed electrodes. Currently, most photovoltaic screens are made of materials such as ordinary carbon steel and aluminum alloy. Ordinary carbon steel has poor corrosion resistance and is prone to rusting in the humid environment of photovoltaic production, resulting in a short screen lifespan (generally ≤300 prints). While aluminum alloy is lightweight, it is prone to deformation at high temperatures (thermal expansion coefficient ≥23×10⁻). 6 / ℃), which is not compatible with the component sintering process.

[0003] Stainless steel materials such as 304 stainless steel have become the preferred substrate for screen printing due to their advantages such as corrosion resistance, high strength, and high temperature resistance. However, existing stainless steel screen printing materials, such as 304 stainless steel screen printing materials, generally use a relatively thick base thickness of 27μm. This can lead to problems such as poor ink penetration and insufficient printing accuracy in thin electrode printing scenarios. Therefore, etching solutions are generally used to thin these stainless steel screen printing materials. However, traditional etching solutions not only have defects such as unstable etching rate, difficulty in controlling the surface roughness of the screen printing material (generally Ra>0.5μm), and low etching uniformity (generally below 95%), but also lack lattice control components, resulting in coarse metal lattices in the thinned stainless steel screen printing material. This can easily lead to stress concentration and decreased tensile strength. As a result, the material advantages of stainless steel such as 304 stainless steel cannot be fully utilized, making it difficult to meet the technical requirements for long-term stable operation of high-efficiency photovoltaic modules. Summary of the Invention

[0004] The purpose of this application is to provide a method for preparing an etching solution, a photovoltaic printing screen and the etching preparation method thereof, which aims to improve the problem that existing etching solutions for thinning stainless steel screens such as 304 stainless steel screens cannot fully utilize the material advantages of stainless steel such as 304 stainless steel and are difficult to meet the technical requirements for long-term stable operation of high-efficiency photovoltaic modules.

[0005] To achieve this objective, embodiments of this application provide a method for preparing an etching solution, the method comprising: Under preset stirring conditions, deionized water and alkyl propylene glycol were mixed and stirred until homogeneous to obtain the target solvent. According to the first preset method, nitric acid, hydrofluoric acid and phosphoric acid are added sequentially to the target solvent to obtain a first solution; According to the second preset method, at least one corrosion-resistant additive is added to the first solution to obtain a second solution; According to the third preset method, a lattice refiner is added to the second solution to obtain an etching solution.

[0006] Optionally, in some embodiments of this application, the preset stirring conditions are: stirring at room temperature for a first preset time; the ambient temperature of the room temperature environment is 20℃~30℃, and the first preset time is 8min~12min; and / or, The content of deionized water in the etching solution is 30% to 35%, and the content of alkyl propylene glycol in the etching solution is 1.5% to 2.5%.

[0007] Optionally, in some embodiments of this application, the step of sequentially adding nitric acid, hydrofluoric acid, and phosphoric acid to the target solvent in a first preset manner to obtain a first solution includes: Nitric acid, hydrofluoric acid, and phosphoric acid are slowly added to the target solvent in sequence, and the mixture is stirred for a second preset time after each component is added, so as to finally obtain the first solution.

[0008] Optionally, in some embodiments of this application, the second preset time is 12 min to 18 min; and / or, The nitric acid content in the etching solution is 10%–11%, the hydrofluoric acid content in the etching solution is 15%–16%, and the phosphoric acid content in the etching solution is 30%–40%.

[0009] Optionally, in some embodiments of this application, the step of adding at least one corrosion-resistant additive to the first solution in a second preset manner to obtain a second solution includes: After adding all the corrosion-resistant additives to the first solution, the mixture is stirred for a third preset time to obtain the second solution.

[0010] Optionally, in some embodiments of this application, the third preset time is 18 min to 22 min; and / or, At least one of the corrosion-resistant additives includes any one or more of water-based rust inhibitors, methyl-1-acrylamido-2-oleoimidazoline, and dodecenylsuccinic anhydride.

[0011] Optionally, in some embodiments of this application, the lattice refiner is a titanate coupling agent, and the preparation method of the titanate coupling agent includes: In a first preset environment, tetrabutyl titanate and isopropanol are added sequentially to a reaction vessel so that the tetrabutyl titanate and the isopropanol undergo at least a partial esterification reaction to generate the intermediate product tetrabutyl titanate-isopropanol. In a second preset environment, acetylacetone is further added to the reaction vessel to cause the acetylacetone to undergo a chelation reaction with titanium ions to generate a chelate. The solution in the reactor is subjected to a pre-selective purification process to remove unreacted isopropanol and acetylacetone, thereby obtaining the titanate coupling agent.

[0012] Furthermore, to achieve this objective, embodiments of this application also provide an etching preparation method for a photovoltaic printing screen, the etching preparation method comprising: A stainless steel mesh screen is provided, and the stainless steel mesh screen is pretreated to fully expose the stainless steel substrate of the stainless steel mesh screen and keep it dry; The above-mentioned etching solution is provided, and the pretreated stainless steel screen is placed in the etching solution in a preset manner for etching treatment until the stainless steel screen is thinned to a preset thickness, thereby obtaining a prototype of a photovoltaic printing screen. The photovoltaic printing screen prototype is then cleaned and dried sequentially to obtain the photovoltaic printing screen.

[0013] Optionally, in some embodiments of this application, the pretreatment includes at least one of degreasing, pickling, and deionized water rinsing, as well as drying; and / or, The step of placing the pretreated stainless steel screen in the etching solution for etching treatment in a preset manner until the stainless steel screen is thinned to a preset thickness to obtain a prototype photovoltaic printing screen includes: placing the pretreated stainless steel screen in the etching solution, controlling the ambient temperature at 25℃~35℃, controlling the etching time at 12min~20min, and using ultrasonic-assisted stirring during the etching process to obtain the prototype photovoltaic printing screen; and / or, The cleaning process includes rinsing with deionized water, and the drying process includes dehydration and drying.

[0014] In addition, to achieve this purpose, this application embodiment also provides a photovoltaic printing screen, which is prepared by the etching preparation method described above.

[0015] Compared with the prior art, this application has the following beneficial effects: Since the etching solution of this application uses a mixture of deionized water and alkyl propylene glycol as a solvent during preparation, the solvent can ensure sufficient interaction between the components and the object to be etched (e.g., 304 stainless steel) through the properties of deionized water, and also ensure a more stable chemical interaction between the components and the object to be etched (e.g., 304 stainless steel) through the good alkalinity, reactivity, and emulsification and dispersing properties of alkyl propylene glycol in specific systems. Simultaneously, the etching solution of this application also uses nitric acid as the main etchant during preparation, making it more compatible with the corrosion resistance characteristics of the object to be etched (e.g., 304 stainless steel) and achieving uniform surface dissolution; and uses hydrofluoric acid as an auxiliary etchant, enabling it to remove the surface oxide film of the object to be etched (e.g., 304 stainless steel) during etching, improving the stability of the etching rate; and uses phosphoric acid as a corrosion inhibitor, effectively controlling the etching depth, reducing the surface roughness of the object to be etched (e.g., 304 stainless steel), and protecting the substrate structure. Furthermore, the etching solution of this application also contains a lattice refiner during preparation, which refines the lattice size of the material to be etched (e.g., 304 stainless steel) during etching, thereby improving its tensile strength. It also contains at least one corrosion-resistant additive, which enhances the corrosion resistance of the material to be etched (e.g., 304 stainless steel) during etching. Thus, the photovoltaic printing screen of this application can use stainless steel, such as 304 stainless steel, as a substrate and achieve precise thinning from 27μm to 15μm using the aforementioned etching solution. This means that the etching uniformity is improved to over 99% while ensuring a high-precision surface quality of the thinned screen. In addition, it ensures that the metal lattice size of the thinned screen is refined, fully utilizing the material advantages of stainless steel such as 304 stainless steel, and improving the tensile strength, corrosion resistance, and service life of the screen. Therefore, this technical solution effectively improves upon existing etching solutions for thinning stainless steel screens such as 304 stainless steel, which fail to fully utilize the material advantages of stainless steel and thus cannot meet the technical requirements for the long-term stable operation of high-efficiency photovoltaic modules. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0017] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0018] Figure 1 This is a flowchart illustrating the preparation method of the etching solution in an embodiment of this application.

[0019] Figure 2 This is a flowchart illustrating the preparation method of the titanate coupling agent in the embodiments of this application.

[0020] Figure 3 This is a flowchart illustrating the etching preparation method of the photovoltaic printing screen according to an embodiment of this application. Detailed Implementation

[0021] To make the inventive objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In the description of this application, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0023] The technical solution of this application will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] Please see Figure 1 As shown, in one embodiment, this application provides a method for preparing an etching solution, which specifically includes: Step S11: Under preset stirring conditions, deionized water and alkyl propylene glycol trimethylamine are mixed and stirred until homogeneous to obtain the target solvent.

[0025] It is understood that the etching solution prepared by the method in this application embodiment is mainly used for thinning photovoltaic printing screens made of stainless steel materials such as 304 stainless steel. The deionized water mentioned above specifically refers to water in which most soluble salts and charged ions (such as calcium ions Ca²⁺, magnesium ions Mg²⁺, sodium ions Na⁺, chloride ions Cl⁻, sulfate ions SO₄²⁻, etc.) have been removed through a special process (such as ion exchange or reverse osmosis (RO)). Therefore, the method step in this application uses the target solvent obtained by mixing deionized water with alkyl propylene glycol under preset stirring conditions and stirring until homogeneous as the solvent for the final etching solution. This effectively eliminates interference from various impurity ions, ensuring that each component in the etching solution can fully interact with the object to be etched (e.g., 304 stainless steel), thus guaranteeing etching uniformity while avoiding the influence of various impurity ions on the surface quality of the object to be etched (e.g., 304 stainless steel). In addition, the good alkalinity, reactivity, and emulsifying and dispersing properties of alkyl propylene glycol in tallow can ensure that the components of the etching solution have a more stable chemical reaction with the object to be etched (such as 304 stainless steel).

[0026] Step S12: Nitric acid, hydrofluoric acid and phosphoric acid are added to the target solvent in sequence according to the first preset method to obtain the first solution.

[0027] Understandably, after obtaining the target solvent through the previous method steps, nitric acid, hydrofluoric acid, and phosphoric acid can be added sequentially to the target solvent according to the first preset method to obtain the first solution. Nitric acid serves as the main etchant in the final etching solution, making it more compatible with the corrosion resistance characteristics of the object to be etched (e.g., 304 stainless steel), achieving uniform surface dissolution. Hydrofluoric acid serves as an auxiliary etchant in the final etching solution, enabling it to remove the surface oxide film of the object to be etched (e.g., 304 stainless steel) during etching, improving the stability of the etching rate. Phosphoric acid serves as a corrosion inhibitor in the final etching solution, effectively controlling the etching depth of the object to be etched (e.g., 304 stainless steel) during etching, reducing the surface roughness of the object to be etched (e.g., 304 stainless steel), and protecting the substrate structure.

[0028] Step S13: According to the second preset method, at least one corrosion-resistant additive is added to the first solution to obtain the second solution.

[0029] It is understandable that after obtaining the first solution through the previous method steps, at least one corrosion-resistant additive can be added to the first solution according to the second preset method to obtain the second solution. The corrosion-resistant additive mentioned here may include, but is not limited to, water-based rust inhibitors, methyl-1-acrylamido-2-oleoimidazoline, dodecenylsuccinic anhydride, etc. Adding at least one corrosion-resistant additive to the first solution in this method step ensures that the final etching solution contains at least one corrosion-resistant additive. These corrosion-resistant additives can enhance the corrosion resistance of the workpiece (e.g., 304 stainless steel) during the etching process.

[0030] Step S14: According to the third preset method, add a lattice refiner to the second solution to obtain an etching solution.

[0031] Understandably, after obtaining the second solution through the previous method steps, a lattice refiner can be added to the second solution according to the third preset method to obtain the etching solution. The lattice refiner mentioned here may include, but is not limited to, titanate coupling agents. Adding the lattice refiner to the second solution in this method step ensures that the final etching solution contains the lattice refiner. During the etching process of the workpiece (e.g., 304 stainless steel), the lattice refiner can simultaneously refine the lattice size of the workpiece (e.g., 304 stainless steel) to improve its tensile strength.

[0032] Thus, the etching solution preparation method of this application embodiment uses a mixture of deionized water and alkyl propylene glycol as a solvent. Therefore, the solvent can ensure that the components and the object to be etched (e.g., 304 stainless steel) can fully interact through the properties of deionized water, and can also ensure a more stable chemical reaction between the components and the object to be etched (e.g., 304 stainless steel) through the good alkalinity, reactivity, and emulsification and dispersion properties of alkyl propylene glycol in a specific system. Furthermore, in preparing the etching solution, nitric acid is used as the main etchant, making the resulting etching solution better match the corrosion resistance characteristics of the object to be etched (e.g., 304 stainless steel), achieving uniform surface dissolution. Hydrofluoric acid is used as an auxiliary etchant, enabling the etching solution to remove the surface oxide film of the object to be etched (e.g., 304 stainless steel) during etching, improving the stability of the etching rate. Phosphoric acid is used as a corrosion inhibitor, allowing the resulting etching solution to effectively control the etching depth of the object to be etched (e.g., 304 stainless steel), reduce the surface roughness of the object to be etched (e.g., 304 stainless steel), and protect the substrate structure. In addition, a lattice refiner is added during the preparation of the etching solution, allowing the resulting etching solution to refine the lattice size of the object to be etched (e.g., 304 stainless steel) during etching, thereby improving its tensile strength. At least one corrosion-resistant additive is also added, enabling the resulting etching solution to give the object to be etched (e.g., 304 stainless steel) superior corrosion resistance during etching.

[0033] In some examples, the aforementioned preset stirring conditions are: room temperature and a first preset stirring time. This setting ensures that deionized water and alkyl propylene glycol triglycerides are thoroughly mixed at room temperature, resulting in a more uniform target solvent and providing a more stable solvent environment for the subsequent etching solution. Furthermore, the aforementioned room temperature is 20°C–30°C, and the first preset stirring time is 8–12 minutes. This setting better suits the daily use environment of the etching solution and ensures that the stirring time, while maintaining the overall efficiency of etching solution preparation, also ensures thorough mixing of the deionized water and alkyl propylene glycol triglycerides.

[0034] In some examples, the deionized water content in the final etching solution is 30%–35%, and the content of alkyl propylene glycol triglyceride (EPD) is 1.5%–2.5%. Thus, by designing the parameters for the deionized water, the final etching solution is a concentrated system, meaning that the remaining 65%–70% consists of other active ingredients (such as nitric acid, hydrofluoric acid, and phosphoric acid). This indicates a high-productivity formulation; the high concentration of active ingredients ensures a rapid etching rate and improves production efficiency. Furthermore, by designing the parameters for the EPD, the EPD content in the final etching solution is also controlled at a relatively high level. This allows the EPD to further utilize its good alkalinity, reactivity, and emulsifying and dispersing properties in specific systems, ensuring a more stable chemical reaction between the components of the final etching solution and the workpiece (e.g., 304 stainless steel).

[0035] It should be noted that, in this example, the content of deionized water in the final etching solution is preferably 32%. The content of tallow alkylpropylene diamine in the final etching solution is preferably 2%.

[0036] In some examples, the process of performing the above method step "adding nitric acid, hydrofluoric acid, and phosphoric acid sequentially to the target solvent in a first preset manner to obtain a first solution" is as follows: Nitric acid, hydrofluoric acid, and phosphoric acid are slowly added to the target solvent sequentially, and the mixture is stirred for a second preset time after each component is added, to finally obtain the first solution. In this way, the above method steps ensure that each component (i.e., nitric acid, hydrofluoric acid, and phosphoric acid) is thoroughly mixed with the target solvent after being added. Furthermore, ensuring that each component is thoroughly mixed with the target solvent before adding the next component avoids the problem of sudden local temperature rises that could affect the quality of the final etching solution.

[0037] It should be noted that the second preset time in this example is 12 min to 18 min. This ensures that the stirring time setting ensures the overall preparation efficiency of the etching solution while ensuring that each component is fully mixed with the target solvent.

[0038] In some examples, the content of nitric acid in the final etching solution is 10%–11%, hydrofluoric acid is 15%–16%, and phosphoric acid is 30%–40%. Based on the above description, nitric acid can be used as the primary etchant in the final etching solution, hydrofluoric acid as an auxiliary etchant, and phosphoric acid as a corrosion inhibitor. Thus, through the synergistic effect of these three parameters, the final etching solution can achieve a faster and more controllable etching rate, better suited to the etching design of high-alloy materials such as 304 stainless steel containing easily passivated elements like chromium and titanium. Simultaneously, it ensures that after etching and thinning stainless steel materials such as 304 stainless steel, a clean, uniform, and passivation-free matte or slightly glossy surface can be obtained.

[0039] It should be noted that, in this example, the content of nitric acid in the final etching solution is preferably 10.5%. The content of hydrofluoric acid in the final etching solution is preferably 15.4%. The content of phosphoric acid in the final etching solution is preferably 35%. With the combination of these proportions, the etching thinning treatment of 304 stainless steel has the best etching effect.

[0040] In some examples, the specific process of performing the above method step "adding at least one corrosion-resistant additive to the first solution according to the second preset method to obtain the second solution" is as follows: after adding all corrosion-resistant additives to the first solution, stirring for a third preset time to obtain the second solution. Thus, by setting the above method steps, it can be ensured that all corrosion-resistant additives added to the first solution can be thoroughly stirred and mixed with the first solution to obtain a more uniform second solution.

[0041] It should be noted that the third preset time in this example is 18 min to 22 min. This setting of the stirring time ensures that the preparation efficiency of the entire etching solution is guaranteed, while also ensuring that all corrosion-resistant additives are fully mixed with the first solution.

[0042] In some examples, the aforementioned corrosion-resistant additive may specifically include one or more of water-based rust inhibitors, methyl-1-acrylamido-2-oleoimidazoline, and dodecenylsuccinic anhydride (K12). Thus, through the design of the aforementioned corrosion-resistant additives, the final etching solution can impart superior corrosion resistance to the workpiece (e.g., 304 stainless steel) while etching.

[0043] It should be noted that the water-based rust inhibitor in this example is preferably a novel Gemini structure modified with polycarboxylate. Compared with traditional single-chain surfactants, the Gemini structure has a lower critical micelle concentration and a stronger ability to adsorb on the metal surface. It can be more firmly and densely adsorbed on the fresh metal surface exposed by etching, forming a monomolecular protective film. This film can effectively block corrosive ions such as H⁺ and Cl⁻ in the etching solution from contacting the metal substrate, thereby inhibiting excessive corrosion of the metal (i.e., reducing the risk of "hydrogen embrittlement") and rust re-rust between processes. Therefore, it can be used as a main corrosion inhibitor or an interfacial activity inhibitor in the etching solution in this example. In this example, methyl-1-acrylamido-2-oleoimidazoline can be used as a synergistic corrosion inhibitor or an adsorption film-forming enhancer, meaning it can be the "golden partner" of the main corrosion inhibitor. Its main function is to synergistically enhance and strengthen the protective film. This is because the nitrogen atom on the imidazoline ring can form a coordinate bond with a metal atom (such as iron), which is a more robust chemical adsorption than physical adsorption. At the same time, the molecular structure of methyl-1-acrylamido-2-oleoimidazoline can adsorb in areas not fully covered or weakly adsorbed by Gemini molecules, forming a more complete and robust mixed protective film together with Gemini molecules, greatly improving the stability and durability of the protective effect. In this example, dodecenyl succinic anhydride can be used as a hydrophobic agent or inter-process rust inhibitor. Its main function focuses on "rust prevention," particularly preventing "inter-process rusting" in the short period after the workpiece is removed from the etching tank and before entering the next cleaning process. Simultaneously, in acidic aqueous solutions, dodecenyl succinic anhydride hydrolyzes to generate the corresponding carboxylic acid. These carboxylic acid molecules are anchored to the metal surface with their polar groups (-COOH), while the non-polar long-chain alkyl groups are neatly oriented outwards, thus forming a hydrophobic film on the metal surface. This hydrophobic film effectively repels water molecules and blocks oxygen, both of which are key factors causing metal rusting in atmospheric environments. Therefore, it provides excellent short-term rust prevention for the workpiece. In addition, dodecenyl succinic anhydride has extremely strong resistance to hard water, preventing the processing fluid from becoming cloudy due to metal ion precipitation and increased water hardness during metal processing.

[0044] In some examples, the aforementioned lattice refiner is preferably a titanate coupling agent, such as... Figure 2 As shown, the preparation method of this titanate coupling agent may specifically include: Step S21: Under the first preset environment, tetrabutyl titanate and isopropanol are added sequentially to the reactor so that tetrabutyl titanate and isopropanol undergo at least partial esterification reaction to generate the intermediate product tetrabutyl titanate-isopropanol.

[0045] It is understood that the titanate coupling agent prepared in this example is mainly composed of tetrabutyl titanate, isopropanol, and acetylacetone. Therefore, before proceeding with this preparation method, the raw materials can be prepared first, specifically tetrabutyl titanate, isopropanol, and acetylacetone in a molar ratio of 1:2:0.5. After preparing these raw materials, tetrabutyl titanate and isopropanol can be added sequentially to the reactor under the first preset environment, so that tetrabutyl titanate and isopropanol undergo at least partial esterification reaction to generate the intermediate product tetrabutyl titanate-isopropyl titanate. The first preset environment mentioned here is preferably a sealed environment filled with nitrogen, with an ambient temperature of 40℃~50℃ and a stirring duration of 50min~70min. This ensures that tetrabutyl titanate and isopropanol undergo the corresponding esterification reaction under a suitable ambient temperature and in an environment free of impurities, allowing for sufficient mixing and the generation of the intermediate product tetrabutyl titanate-isopropyl titanate. Furthermore, tetrabutyl titanate can be added to the reactor first, and then the reactor can be placed in a sealed environment under nitrogen protection and with an ambient temperature of 40℃~50℃. Isopropanol can then be added slowly and stirred for more than 60 minutes.

[0046] Step S22: Under the second preset environment, acetylacetone is further added to the reactor to allow acetylacetone to chelate with titanium ions to form a chelate.

[0047] Understandably, after generating the intermediate product tetrabutyl titanate-isopropyl titanate through the above steps, acetylacetone can be further added to the reactor under a second preset environment to allow acetylacetone to chelate with titanium ions, forming a chelate. The second preset environment is preferably a sealed environment filled with nitrogen, with an ambient temperature of 65℃~70℃ and a stirring duration of 80min~100min. This ensures that acetylacetone and titanium ions are thoroughly mixed in a contaminant-free environment at a suitable temperature, allowing for the chelation reaction and the formation of the chelate, while simultaneously inhibiting the hydrolysis of titanium ions.

[0048] Step S23: Perform a pre-selective purification treatment on the solution in the reactor to remove unreacted isopropanol and acetylacetone, and obtain titanate coupling agent.

[0049] Understandably, after producing the chelate through the above steps, the solution in the reactor can be further purified to remove unreacted isopropanol and acetylacetone, yielding a titanate coupling agent. This purification process includes, but is not limited to, vacuum distillation (0.08 MPa–0.09 MPa, 80°C–85°C) to remove unreacted isopropanol and acetylacetone. At this point, a pale yellow, transparent liquid is obtained, which is the titanate coupling agent (lattice refiner).

[0050] Experimental results show that the titanate coupling agent prepared by the above method has a purity of ≥98%.

[0051] In one embodiment, such as Figure 3 As shown in the embodiments of this application, an etching preparation method for a photovoltaic printing screen is also provided. This etching preparation method for the photovoltaic printing screen specifically includes: Step S31: Provide a stainless steel screen and pre-treat the stainless steel screen to fully expose the stainless steel substrate and keep it dry.

[0052] Understandably, the stainless steel mesh used in this example is preferably made of 304 stainless steel. This is because 304 stainless steel contains 18% chromium and 8% nickel, which can form a dense chromium oxide protective film on the surface. This film effectively resists corrosion in the humid environment of photovoltaic production and in the presence of slightly corrosive gases (such as trace amounts of hydrochloric acid and hydrofluoric acid volatiles). After a neutral salt spray test (5% sodium chloride solution, 35℃), the rust-free time is ≥1000h, which is more than 5 times better than that of ordinary carbon steel mesh (≤200h), significantly extending the mesh replacement cycle. Furthermore, the 304 stainless steel mesh has a room temperature tensile strength ≥515MPa and a yield strength ≥205MPa, maintaining excellent structural stability even when thinned to 15μm. Under printing pressure (0.1 MPa~0.3 MPa), the screen deformation is ≤0.02mm, ensuring that the electrode linewidth accuracy is controlled within ±5μm. This solves the problem of easy stretching and deformation of ordinary aluminum alloy screens (tensile strength ≤300MPa after thinning). Furthermore, the coefficient of thermal expansion of 304 stainless steel screens is only 17.2×10⁻ in the temperature range of 20℃~100℃. 6 / ℃, far lower than ordinary aluminum alloys (23.1×10⁻ 6 Therefore, in the photovoltaic module sintering process (temperature 200℃~500℃), the dimensional change rate of the 304 stainless steel screen is ≤0.1%, which can effectively avoid electrode misalignment and line width deviation caused by thermal deformation and ensure printing consistency.

[0053] Since the base thickness of 304 stainless steel screen is generally 27μm, it cannot meet the requirements of thin electrode printing scenarios. Therefore, it is necessary to use this etching preparation method to etch and thin it. Before the etching and thinning process, the stainless steel screen needs to be pretreated by the steps of this method to fully expose the stainless steel substrate of the stainless steel screen and keep it dry, so as to ensure the effect of the subsequent etching and thinning process.

[0054] Step S32: Provide the etching solution of the above embodiment, place the pretreated stainless steel screen in the etching solution for etching treatment in a preset manner until the stainless steel screen is thinned to a preset thickness, and obtain the prototype of the photovoltaic printing screen.

[0055] It is understandable that after the stainless steel substrate of the stainless steel screen is fully exposed and kept dry through the above methods and steps, the stainless steel plate can be etched and thinned accordingly. Specifically, the etching solution prepared in the above embodiment is provided, and the pretreated stainless steel screen is placed in the etching solution in a preset manner for etching treatment until the stainless steel screen is thinned to the preset thickness, and a photovoltaic printing screen prototype is obtained.

[0056] Step S33: Clean and dry the photovoltaic printing screen prototype in sequence to obtain the photovoltaic printing screen.

[0057] It is understandable that after obtaining the prototype of the photovoltaic printing screen through the above methods and steps, the prototype of the photovoltaic printing screen can be further cleaned (including but not limited to removing the etching solution adhering to its surface) and dried to obtain the photovoltaic printing screen.

[0058] Thus, the etching preparation method for the photovoltaic printing screen of this application embodiment, through the above-described steps, enables the photovoltaic printing screen to be precisely thinned from 27μm to 15μm using stainless steel such as 304 stainless steel as the substrate, and through the aforementioned etching solution. This achieves an etching uniformity of over 99% while ensuring high-precision surface quality of the thinned screen. Furthermore, it ensures refined metal lattice dimensions in the thinned screen, fully leveraging the material advantages of stainless steel such as 304 stainless steel, and improving the screen's tensile strength, corrosion resistance, and service life.

[0059] In some examples, the aforementioned pretreatment may specifically include at least one of degreasing, pickling, and deionized water rinsing, as well as drying. Thus, these method steps ensure that the stainless steel substrate of the pretreated stainless steel mesh is adequately exposed and kept dry.

[0060] It should be noted that the degreasing treatment in this example specifically involves immersing the stainless steel mesh in a 4%–6% sodium hydroxide solution at a temperature of 45℃–55℃ for 14–16 minutes. The pickling treatment in this example specifically involves immersing the stainless steel mesh in a 3%–5% nitric acid solution at a room temperature of 25℃–35℃ for 4–6 minutes. The deionized water rinsing treatment in this example can be performed two to four times, with each rinsing lasting 1.5–2.5 minutes. This effectively removes surface oil and oxide layers from the stainless steel mesh, fully exposing the stainless steel substrate of the 304 stainless steel mesh. The drying treatment in this example specifically involves drying in a vacuum drying oven at 60℃–70℃.

[0061] In some examples, the specific process of performing the above method step "immersing the pretreated stainless steel screen in an etching solution for etching treatment in a preset manner until the stainless steel screen is thinned to a preset thickness to obtain a photovoltaic printing screen prototype" is as follows: After placing the pretreated stainless steel screen in the etching solution, the ambient temperature is controlled at 25℃~35℃, the etching time is controlled at 12min~20min, and ultrasonic-assisted stirring is used during the etching process to obtain the photovoltaic printing screen prototype. Thus, by setting the above method steps, it can be ensured that all components of the etching solution fully contact the surface of the stainless steel screen during the etching process, especially promoting full contact between the lattice refiner and the stainless steel surface, while ensuring uniform etching.

[0062] It should be noted that the working power of the ultrasonic-assisted stirring device in this example is preferably 300W to 350W, and the frequency is preferably 28kHz.

[0063] In some examples, the cleaning process mentioned above includes rinsing with deionized water, and the drying process includes dehydration and baking. Thus, these processes ensure that the final photovoltaic printing screen is clean and dry.

[0064] It should be noted that the number of deionized water rinses in this example can be two to four times, with each rinse lasting 2.5 to 3.5 minutes. The dehydration treatment in this example can be anhydrous ethanol dehydration treatment. The drying treatment in this example can be continuous drying in a vacuum drying oven at 60°C to 70°C for 25 to 30 minutes.

[0065] In one embodiment, this application also provides a photovoltaic printing screen, which is prepared by the etching method described in the above embodiments. Thus, since the photovoltaic printing screen of this application is prepared by the etching method described in the above embodiments, it allows the photovoltaic printing screen to use stainless steel, such as 304 stainless steel, as a substrate, and achieve precise thinning from 27μm to 15μm using the aforementioned etching solution. This means that the etching uniformity is improved to over 99%, while ensuring that the thinned screen has a high-precision surface quality. Furthermore, it ensures that the metal lattice size of the thinned screen is refined, fully utilizing the material advantages of stainless steel, such as 304 stainless steel, and improving the tensile strength, corrosion resistance, and service life of the screen.

[0066] The technical effects of the proposed solution are further illustrated below through comparative experiments shown in Tables 1 and 2: As can be seen from the comparison between the example and Comparative Example 1, compared with the 304 stainless steel screen obtained after thinning treatment with traditional etching solution, it has defects such as poor etching precision, poor etching uniformity, low yield, poor corrosion resistance, poor high temperature stability, large and irregular lattice, and poor tensile strength. The 304 stainless steel screen obtained after the etching process of the present invention has significantly improved etching precision, etching uniformity, yield, corrosion resistance, and high temperature stability. At the same time, it refines the metal lattice size of the screen and greatly improves the tensile strength of the screen.

[0067] Comparing Comparative Example 1 and Comparative Example 2, it can be seen that, compared to the traditional etching solution of Comparative Example 1, which is simply a mixture of nitric acid and hydrofluoric acid, the etching solution of Comparative Example 2 is prepared by reasonably adjusting the ratio of nitric acid and hydrofluoric acid, using deionized water and alkyl propylene glycol as solvents, and adding phosphoric acid. This can improve the etching precision, etching uniformity, yield, and surface roughness of the 304 stainless steel mesh obtained after thinning treatment.

[0068] Comparing Examples 3, 4, and 5, it can be seen that compared to adding only one of the following rust inhibitors during the etching solution preparation process: 0.5% of a novel Gemini-structured water-based rust inhibitor modified with polycarboxylate, 0.6% of methyl-1-acrylamido-2-oleoimidazoline, and 2.8% of dodecenylsuccinic anhydride (K12), the combined addition of all three rust inhibitors significantly improves the rust resistance of the 304 stainless steel mesh obtained after thinning treatment.

[0069] Comparing the examples and Comparative Example 6, it can be seen that adding a lattice refiner (i.e., titanate coupling agent) during the preparation of the etching solution can further improve the etching precision, etching uniformity and surface roughness of the 304 stainless steel screen obtained after thinning treatment, while refining the metal lattice size of the screen and significantly improving the tensile strength of the screen.

[0070] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for preparing an etching solution, characterized by, The preparation method includes: Under preset stirring conditions, deionized water and alkyl propylene glycol were mixed and stirred until homogeneous to obtain the target solvent; According to the first preset method, nitric acid, hydrofluoric acid and phosphoric acid are added sequentially to the target solvent to obtain a first solution; According to the second preset method, at least one corrosion-resistant additive is added to the first solution to obtain a second solution; According to the third preset method, a lattice refiner is added to the second solution to obtain an etching solution; The content of deionized water in the etching solution is 30% to 35%, the content of alkyl propylene glycol in the etching solution is 1.5% to 2.5%, the content of nitric acid in the etching solution is 10% to 11%, the content of hydrofluoric acid in the etching solution is 15% to 16%, and the content of phosphoric acid in the etching solution is 30% to 40%.

2. The production method according to claim 1, characterized by, The preset stirring conditions are: stirring at room temperature for a first preset time; the ambient temperature of the room temperature environment is 20℃~30℃, and the first preset time is 8min~12min.

3. The preparation method according to claim 1, characterized in that, The step of sequentially adding nitric acid, hydrofluoric acid, and phosphoric acid to the target solvent according to a first preset method to obtain a first solution includes: Nitric acid, hydrofluoric acid, and phosphoric acid are slowly added to the target solvent in sequence, and the mixture is stirred for a second preset time after each component is added, so as to finally obtain the first solution.

4. The preparation method according to claim 3, characterized in that, The second preset time is 12 min to 18 min.

5. The preparation method according to claim 1, characterized in that, The step of adding at least one corrosion-resistant additive to the first solution to obtain the second solution according to the second preset method includes: After adding all the corrosion-resistant additives to the first solution, the mixture is stirred for a third preset time to obtain the second solution.

6. The preparation method according to claim 5, characterized in that, The third preset time is 18 min to 22 min; and / or, At least one of the corrosion-resistant additives includes any one or more of water-based rust inhibitors, methyl-1-acrylamido-2-oleoimidazoline, and dodecenylsuccinic anhydride.

7. The preparation method according to any one of claims 1-6, characterized in that, The lattice refiner is a titanate coupling agent, and the preparation method of the titanate coupling agent includes: In a first preset environment, tetrabutyl titanate and isopropanol are added sequentially to a reaction vessel so that the tetrabutyl titanate and the isopropanol undergo at least a partial esterification reaction to generate the intermediate product tetrabutyl titanate-isopropanol. In a second preset environment, acetylacetone is further added to the reaction vessel to cause the acetylacetone to undergo a chelation reaction with titanium ions to generate a chelate. The solution in the reactor is subjected to a pre-selective purification process to remove unreacted isopropanol and acetylacetone, thereby obtaining the titanate coupling agent.

8. A method for etching a photovoltaic printing screen, characterized in that, The etching preparation method includes: A stainless steel mesh screen is provided, and the stainless steel mesh screen is pretreated to fully expose the stainless steel substrate of the stainless steel mesh screen and keep it dry; An etching solution as described in any one of claims 1-7 is provided, and the pretreated stainless steel screen is placed in the etching solution in a preset manner for etching treatment until the stainless steel screen is thinned to a preset thickness to obtain a prototype of a photovoltaic printing screen. The photovoltaic printing screen prototype is then cleaned and dried sequentially to obtain the photovoltaic printing screen.

9. The etching preparation method according to claim 8, characterized in that, The pretreatment includes at least one of degreasing, pickling, and deionized water rinsing, as well as drying; and / or, The step of placing the pretreated stainless steel screen in the etching solution for etching treatment in a preset manner until the stainless steel screen is thinned to a preset thickness to obtain a prototype photovoltaic printing screen includes: placing the pretreated stainless steel screen in the etching solution, controlling the ambient temperature at 25℃~35℃, controlling the etching time at 12min~20min, and using ultrasonic-assisted stirring during the etching process to obtain the prototype photovoltaic printing screen; and / or, The cleaning process includes rinsing with deionized water, and the drying process includes dehydration and drying.

10. A photovoltaic printing screen, characterized in that, The photovoltaic printing screen is prepared by the etching preparation method as described in claim 8 or 9.

Images