Processing technology of embedded metal polymer flexible composite meshless screen printing for photovoltaic cell

Abstract

This invention belongs to the technical field of semiconductor microfabrication, specifically a processing technology for embedded metal-polymer flexible composite meshless screen printing for photovoltaic cells. The process involves fabricating a micro-electroformed metal film with patterned through-holes, forming a framework, using a non-silicon semiconductor electrochemical additive micro-nano mechanical manufacturing process. A non-curing organic polymer liquid material of the same material is injected into specific through-holes of the metal film using a precision CNC injection process, and after semi-curing, anchor pillars are formed that are interconnected vertically. The flow or semi-flow characteristics of the non-curing organic polymer and vacuum negative pressure are used to perform a micropore filling and coating process to connect the anchor pillars and the metal film, forming an embedded metal-polymer structure. The anchor pillars and metal film are then fully cured and fused together, significantly improving the product yield while ensuring the overall strength and elastic modulus of the composite film. This also results in a more stable service life for batch printing screens.

Description

Technical Field

[0001] This invention relates to the technical field of semiconductor processing, specifically to a process for processing embedded metal-polymer flexible composite meshless screen printing plates for photovoltaic cell printing. Background Technology

[0002] Crystalline silicon solar cells typically employ screen printing technology to obtain electrodes during manufacturing. Screenless stencils are printing carriers with various patterns created through electrodeposition and electroforming processes. This allows conductive grid paste to pass through the grid pattern onto the silicon wafer, forming the upper and lower electrodes. Heating causes the organic solvents in the paste to evaporate, thus forming the solar cell electrodes. Screens for photovoltaic printed solar cells are a crucial component of cell production; the main product types include back-field stencils, back electrode stencils, main grid positive grid stencils, and fine grid positive grid stencils.

[0003] Electroforming screens are made using E-Fab (photolithography electroforming microfabrication) technology to create nickel or nickel alloy sheets with specific patterns identical to the battery gate. After being peeled off into a self-supporting film, the screen is stretched and fixed onto a frame. A PI (polyimide) flexible film can be applied to the printing surface in advance or later to become a solar conductive electrode printing mask, commonly known as a printing screen.

[0004] To address the issues of low strength, short lifespan, and unstable quality in electroformed stencils for solar cell grid printing, a solution is proposed: a flexible composite meshless stencil fabrication process for embedded metal-polymer printing for photovoltaic cells. Summary of the Invention

[0005] To address the above problems, the present invention provides the following technical solution: A process for processing an embedded metal-polymer flexible composite meshless screen for photovoltaic cell printing includes: Step 1: The skeleton of the embedded metal polymer composite meshless screen and the micro-electroformed metal film with through-hole pattern are prepared by non-silicon semiconductor electrochemical additive micro-nano mechanical manufacturing process; Step 2: Using a precision CNC injection process, inject a semi-cured organic polymer liquid material of the same material to form an anchoring column with interconnected upper and lower sections. Step 3: Using the flow or semi-flow properties of non-curing organic polymers and vacuum negative pressure, a micropore filling coating process is used to connect the anchoring post and the metal film to form an embedded metal polymer structure. Step 4: The anchoring posts and the metal film are connected by full curing fusion, and femtosecond laser windowing is performed on specific graphic areas to form an embedded metal polymer flexible composite screen printing plate without mesh nodes.

[0006] Furthermore, step one includes generating a patterned mask using computer-aided design tools based on the structural design of the target solar grid printing screen. Glass is selected as the carrier plate to ensure the flatness and stability of the subsequent film layer. The carrier plate is cleaned and surface treated to remove surface contaminants and ensure that its surface is clean and smooth. Using semiconductor electrochemical additive microfabrication technology, a metal film with a specific design pattern is micro-electrocast onto a glass substrate after being coated with a flexible material and metallized. The self-supporting patterned metal film after peeling is used as the metal film layer of the skeleton in the embedded structure. In the through-holes of the upper and lower structures of the metal thin film, an uncured organic polymer material is filled into the through-holes using a dispensing process. The filled semi-preform is heat-treated to transform it into a semi-cured state.

[0007] Furthermore, step one includes selecting a carrier plate material, cleaning and surface treating the carrier plate; selecting a flexible substrate material, designing a metallization seed layer nanoscale metal film system on the substrate material, forming a conductive nanofilm by physical vapor deposition, coating the conductive nanofilm surface with photoresist according to design specifications, and exposing and developing the photoresist with a specific design pattern. Then, the entire assembly material is placed in an electrolyte containing metal ions, and electrochemical additive deposition is performed on the exposed conductive nanofilm area. This electrochemically deposited metal film with a specific design pattern becomes a micro-electroformed self-supporting metal film after being peeled off. Polymer materials are introduced into the upper and lower layers of the metal film and at specific opening locations. The introduced polymer materials are cured to ensure tight bonding of the metal film. Through curing modification methods, the bonding force between the metal film and the polymer materials is enhanced to prevent delamination or peeling. The prepared embedded metal polymer structure is tested for mechanical strength, mechanical deformation, interface bonding state, wet weight of printed grid lines, and grid line morphology.

[0008] Furthermore, step two includes determining the applied current density during electrodeposition to control the deposition rate and uniformity of the metal thin film, calculated as follows: , Where J is the current density, I is the deposition current, and A is the electrode area; Ensure the concentration and pH of the metal ions in the electrolyte are suitable for the electrodeposition process, and calculate the deposition time to obtain the required metal film thickness, as follows: , Where t is the deposition time, d is the film thickness, A is the electrode surface area, J is the current density, and ρ is the metal density; Determine the curing temperature and time of the polymer material to ensure good bonding with the metal film. The curing temperature is determined based on the glass transition temperature of the material, and the curing time is 1–3 hours. The interfacial bonding strength between the polymer material and the metal film in the upper and lower double-layer sandwich structure was evaluated and calculated as follows: , Where σ is the interfacial bonding strength, F is the tensile force, and A is the test area.

[0009] Furthermore, step two includes selecting a polymer material according to process requirements, considering the material's melting point, viscosity, thermal stability, especially curing characteristics, as well as the mechanical properties after curing. Suitable liquid polymer raw materials of the same material and precision digital control dispensing equipment are selected to ensure accurate and quantitative injection of the liquid polymer material into specific through-holes in the metal film. The liquid polymer material has good fluidity, facilitating filling and spreading, ensuring uniform and equal filling during the filling process, reducing blockages or voids. A vacuum evacuation step is added to ensure refilling in a vacuum environment, using negative pressure to accelerate material filling into the micropores and eliminate microbubbles. Then, the workpiece with the filled through-holes and substrate is placed in an oven to semi-cur the material according to the curing curve.

[0010] Furthermore, step four also includes setting a suitable full-curing temperature based on the thermal properties of the material to avoid overheating that could lead to material decomposition or performance degradation, ensuring that the material is fully cured and formed, while avoiding excessive curing time that could increase energy consumption. For photosensitive polymer materials, ultraviolet light is used to directly pattern and cure them. The irradiation time is adjusted according to the photosensitivity and thickness of the material to ensure uniform curing. The polymer material is further melted and bonded to the anchor post by pressure heating softening and fusion bonding, and then tightly adhered to the metal film. The upper and lower polymer film layers form intermolecular bonds with the anchor post, ensuring that the material and the metal film are in full contact and mechanically embedded during the fusion process, avoiding delamination or voids. Based on the performance test results, optimize parameters such as substrate treatment, polymer material selection, filling process, and curing conditions to improve filling quality and product performance.

[0011] Furthermore, step four includes evaluating the mechanical strength, corrosion resistance, and thermal stability of candidate materials; selecting materials for printing screen applications; designing the structure of composite materials to optimize overall performance; improving the bonding force between the substrate and polymer materials through surface treatment; optimizing the microporous structure to improve the strength and flexibility of the materials; optimizing the bonding force at the material interface to improve the durability of the overall structure; regulating the microstructure of the polymer materials to improve their mechanical properties and durability; and optimizing the preparation process parameters to ensure that the material performance reaches its optimal state.

[0012] Furthermore, in step two, a dispensing process is used to place the uncured organic polymer material into specific upper and lower structural through-holes of the metal diaphragm; a vacuum degassing device is used to fully fill the specific upper and lower structural through-holes of the metal diaphragm with the uncured organic polymer material; the filled semi-pre-product is heat-treated to transform it into a semi-cured state; the semi-cured organic polymer material is bonded to a cured organic polymer material of the same material; the cured organic polymer film layer and the semi-cured organic polymer film layer are hot-pressed; the hot-pressed material is then subjected to a second curing process to achieve a fusion state of intermolecular bonding between the semi-cured organic polymer film layer and the upper cured organic polymer film layer.

[0013] Furthermore, step three includes using a femtosecond laser for high-precision positioning and ablation to open windows in the upper and lower printing pastes.

[0014] Furthermore, step two includes using an electroforming process to manufacture a nickel or nickel alloy metal intermediate film layer with a specific pattern.

[0015] Compared with the prior art, the beneficial effects of the present invention are: In the processing technology of the embedded metal polymer flexible composite meshless screen printing stencil for photovoltaic cell printing, the embedded metal polymer flexible composite meshless screen printing stencil is prepared by using a non-silicon semiconductor electrochemical additive micro-nano mechanical manufacturing process. The stencil has a micro-electroformed metal film with patterned through holes and acts as a skeleton. A non-curing organic polymer liquid material of the same material is injected into specific through holes of the metal film using a precision CNC injection process, and after semi-curing, anchoring columns are formed that are connected vertically. The flow or semi-flow characteristics of the non-curing organic polymer and vacuum negative pressure are used to fill micropores and coat the anchoring columns and the metal film to form an embedded metal polymer structure. Finally, the anchoring columns and the metal film are connected by full curing fusion, and femtosecond laser windowing is performed on specific patterned areas to form the embedded metal polymer flexible composite meshless printing stencil. Overall, the mechanical strength and printing lifespan of the solar grid printing screen products are improved through material structure design and microstructure optimization. While ensuring the overall strength and elastic modulus of the composite film layer, the product qualification rate is also greatly improved. At the same time, while the service life of individual printing screens is improved, the stability of the service life of the overall batch of printing screens is also more stable, as shown by statistical data analysis. Attached Figure Description

[0016] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings; Figure 1This is a schematic diagram illustrating the overall steps of the embedded metal-polymer flexible composite meshless screen printing process for photovoltaic cell printing according to the present invention. Figure 2 This is a schematic diagram of a double-layer sandwich structure for a photovoltaic cell printing embedded metal polymer flexible composite meshless screen printing process according to the present invention.

[0017] Figure label: 1. Upper polyimide film; 2. Metal film; 3. Lower polyimide film. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 like Figures 1-2 As shown, this application provides a process for processing an embedded metal-polymer flexible composite meshless screen for photovoltaic cell printing, comprising: S1: The skeleton of the embedded metal polymer composite meshless screen is prepared by non-silicon semiconductor electrochemical additive micro-nano mechanical manufacturing process, and the micro-electroformed metal film with through hole pattern is prepared. S2: An anchoring column formed by injecting non-curing organic polymer liquid material of the same material into a precision CNC injection process and then semi-curing it. S3: Using the flow or semi-flow properties of non-curing organic polymers and vacuum negative pressure to perform micropore filling and coating process to connect anchoring posts and metal films to form an embedded metal polymer structure; S4: An embedded metal polymer flexible composite screen printing stencil is formed by fully curing and fusing the anchor posts and the metal film, and by performing femtosecond laser windowing on specific graphic areas.

[0020] Specifically, step one includes generating a patterned mask using computer-aided design tools based on the structural design of the target solar grid printing screen; Glass is selected as the carrier plate to ensure the flatness and stability of the subsequent film layer. The carrier plate is cleaned and surface treated to remove surface contaminants and ensure that its surface is clean and smooth. Using semiconductor electrochemical additive microfabrication technology, a metal film with a specific design pattern is micro-electrocast onto a glass substrate after being coated with a flexible material and metallized. The self-supporting patterned metal film after peeling is used as the metal film layer of the skeleton in the embedded structure. In the through-holes of the upper and lower structures of the metal thin film, an uncured organic polymer material is filled into the through-holes using a dispensing process. The filled semi-preform is heat-treated to transform it into a semi-cured state.

[0021] Based on the structural design of the target solar grid printing screen, a patterned mask is generated using computer-aided design (CAD) tools. A high-precision patterned mask is then fabricated using ultraviolet lithography precision equipment to ensure that the mask's linewidth and spacing match the pattern of the target screen.

[0022] Glass is chosen as the carrier plate to ensure the flatness and stability of subsequent film layers. The carrier plate is cleaned and surface-treated to remove surface contaminants, ensuring a clean and smooth surface. A thin metal film (such as nickel or a nickel alloy) is deposited on the carrier plate using an electrodeposition process, serving as the basis for subsequent structures. A metal intermediate film with a specific pattern is manufactured using an electroforming process, ensuring its consistency with the pattern of the target screen.

[0023] A double-layer sandwich structure was fabricated by dispensing uncured organic polymer material into the through-holes of the upper and lower structures of a metal film. Vacuum degassing was used to ensure full filling of the uncured polymer material, achieving a tight bond. The pre-form was then heat-treated to convert it to a semi-cured state. The semi-cured polymer material was then bonded to a cured polymer material of the same material. Hot-pressing was used to ensure a tight bond between the cured and semi-cured polymer film layers. A second curing process was then performed to completely cure the semi-cured polymer material, achieving a fusion state of intermolecular bonding with the upper cured polymer material.

[0024] Photosensitive materials are prepared by adding photosensitive organic polymer materials (such as photosensitive polyimide photoresist) to the outside of the cured polymer film to enhance the photolithography performance of the screen. Femtosecond lasers are used for high-precision positioning and ablation, opening windows for the upper and lower printing pastes to ensure the screen's precision and printing performance. The prepared embedded metal-polymer flexible composite knotless screen is subjected to performance testing to ensure its strength, print life, and mechanical properties meet design requirements. Encapsulation and marking are then performed in preparation for printing production of photovoltaic cells.

[0025] Specifically, step one includes selecting a carrier plate material, cleaning and surface treating the carrier plate; selecting a flexible substrate material, designing a metallization seed layer nanoscale metal film system on the substrate material, forming a conductive nanofilm by physical vapor deposition, coating the conductive nanofilm surface with photoresist according to design specifications, and exposing and developing the photoresist with a specific design pattern. Then, the entire assembly material is placed in an electrolyte containing metal ions, and electrochemical additive deposition is performed on the exposed conductive nanofilm area. This electrochemically deposited metal film with a specific design pattern becomes a micro-electroformed self-supporting metal film after being peeled off. Polymer materials are introduced into the upper and lower layers of the metal film and at specific opening locations. The introduced polymer materials are cured to ensure a tight bond between the metal film and the polymer material. Through curing modification methods, the bonding force between the metal film and the polymer material is enhanced to prevent delamination or peeling. The prepared embedded metal polymer structure is tested for mechanical strength, mechanical deformation, interface bonding state, wet weight of printed grid lines, and grid line morphology.

[0026] In step two, a non-cured organic polymer material is placed into specific upper and lower structural through-holes of a metal film using a dispensing process. A vacuum degassing device is then used to fully fill these through-holes. The pre-formed material is then heat-treated to convert it into a semi-cured state. The semi-cured organic polymer material is then bonded to a cured organic polymer material of the same material. The cured and semi-cured organic polymer films are then hot-pressed. Finally, the hot-pressed material undergoes a second curing process to achieve a fusion state of intermolecular bonding between the semi-cured and upper cured organic polymer films. This includes the use of electroforming processes to create nickel or nickel alloy metal interlayers with specific patterns.

[0027] In one embodiment, step 2 specifically involves generating a patterned mask using computer-aided design (CAD) tools based on the structural design of the target solar grid printing screen. A high-precision patterned mask is then fabricated using ultraviolet lithography precision equipment to ensure that the mask's linewidth and spacing match the pattern of the target screen.

[0028] A support plate is prepared, with glass chosen as the support plate to ensure the flatness and stability of the subsequent film layers. The support plate is then cleaned and surface-treated to remove surface contaminants and ensure its surface is clean and smooth.

[0029] A thin metal film (such as nickel or a nickel alloy) is deposited on a substrate using an electrodeposition process, serving as the base for subsequent structures. An intermediate metal film with a specific pattern is then fabricated using an electroforming process, ensuring its consistency with the pattern of the target stencil.

[0030] A double-layer sandwich structure was fabricated by dispensing uncured organic polymer material into the through-holes of the upper and lower structures of a metal thin film. A vacuum degassing device was then used to ensure complete filling of the uncured polymer material, achieving a tight bond.

[0031] Curing and heat treatment: The filled semi-preform is heat-treated to transform it into a semi-cured state.

[0032] A semi-cured polymer material is bonded to a cured polymer material of the same material. Hot pressing is then used to ensure a tight bond between the cured and semi-cured polymer film layers. A second curing process is then performed to completely cure the semi-cured polymer material, achieving a fusion state of intermolecular bonding with the upper cured polymer material.

[0033] To prepare photosensitive materials, organic polymer materials with photosensitive properties (such as photosensitive polyimide photoresist) are added to the outside of the cured polymer film to enhance the photolithography performance of the screen printing plate.

[0034] Femtosecond laser precision cutting utilizes high-precision positioning and ablation with femtosecond lasers, opening windows for the upper and lower printing paste to ensure the precision of the screen and printing performance.

[0035] Final inspection and packaging involve performance testing of the prepared embedded metal-polymer flexible composite meshless screen to ensure its strength, print life, and mechanical properties meet design requirements. Packaging and marking are then performed in preparation for photovoltaic cell printing production.

[0036] Specifically, step two includes determining the applied current density during electrodeposition to control the deposition rate and uniformity of the metal thin film, calculated as follows: , Where J is the current density, I is the deposition current, and A is the electrode area; Ensure the concentration and pH of the metal ions in the electrolyte are suitable for the electrodeposition process, and calculate the deposition time to obtain the required metal film thickness, as follows: , Where t is the deposition time, d is the film thickness, A is the electrode surface area, J is the current density, and ρ is the metal density; Determine the curing temperature and time of the polymer material to ensure good bonding with the metal film. The curing temperature is determined based on the glass transition temperature of the material, and the curing time is 1–3 hours. The interfacial bonding strength between the polymer material and the metal film in the upper and lower double-layer sandwich structure was evaluated and calculated as follows: , Where σ is the interfacial bonding strength, F is the tensile force, and A is the test area.

[0037] In one embodiment, a mathematical model is established to describe the migration and deposition of metal ions during electrodeposition, predicting the thickness distribution and uniformity of the thin film. An electrochemical kinetic model is used to describe the migration of metal ions in the electrolyte and the deposition process on the electrode surface. Factors considered include current density, electrolyte concentration, and electrode shape.

[0038] Electrochemical simulations were performed using COMSOL Multiphysics or ANSYS. The simulations examined the heat conduction and chemical reactions of polymer materials during the curing process, optimizing the curing process. Heat transfer and chemical kinetic equations were established to describe the temperature distribution and reaction progress during curing. Factors considered included curing temperature, time, and material thermal conductivity.

[0039] Thermodynamic simulations were performed using Abaqus or MATLAB to evaluate the mechanical properties of the embedded metal-polymer structure during the printing process, ensuring its durability and reliability. A three-dimensional finite element model of the structure was established to simulate its deformation and failure behavior under different stress conditions. Factors considered included the material's elastic modulus, Poisson's ratio, and interfacial bonding strength.

[0040] Finite element analysis was performed using ANSYS or COMSOL. Electrodeposition process parameters (such as current density and electrolyte concentration) and polymer curing process parameters (such as temperature and time) were optimized through a combination of experimental and simulation methods. Samples were prepared and their performance was tested (such as film thickness measurement, interfacial bonding strength testing, and mechanical property testing). The experimental results were compared with the model predictions to verify the accuracy of the model.

[0041] Through the above parameter calculations and model building, the fabrication process of embedded metal-polymer flexible composite knotless screens can be systematically optimized, ensuring their high quality and long lifespan. Simultaneously, the model establishment provides theoretical support for further process improvement and innovation.

[0042] Specifically, step two includes selecting a polymer material according to process requirements, considering the material's melting point, viscosity, thermal stability, especially curing characteristics, as well as the mechanical properties after curing. Suitable liquid polymer raw materials of the same material and precision digital control dispensing equipment are selected to ensure accurate and quantitative injection of the liquid polymer material into specific through-holes in the metal film. The liquid polymer material has good fluidity, facilitating filling and spreading, ensuring uniform and equal filling during the filling process, reducing blockages or voids. A vacuum evacuation step is added to ensure refilling in a vacuum environment, using negative pressure to accelerate material filling into the micropores and eliminate microbubbles. Then, the workpiece with the filled through-holes and substrate is placed in an oven to semi-cur the material according to the curing curve.

[0043] Specifically, step four also includes setting a suitable full-curing temperature based on the material's thermal properties to avoid overheating that could lead to material decomposition or performance degradation, ensuring the material is fully cured and formed, while avoiding excessive curing time that could increase energy consumption. For photosensitive polymer materials, ultraviolet light is used to directly pattern and cure them. The irradiation time is adjusted according to the material's photosensitivity and thickness to ensure uniform curing. The polymer material is further melted and bonded to the anchor post using pressure heating to soften and fuse, and then tightly adhered to the metal film. The upper and lower polymer film layers form intermolecular bonds with the anchor post, ensuring that the material and the metal film are in full contact and mechanically embedded during the fusion process, avoiding delamination or voids. Based on performance test results, optimize parameters such as substrate treatment, polymer material selection, filling process, and curing conditions to improve filling quality and product performance. Step three also includes setting an appropriate curing temperature based on the material's thermal properties to avoid overheating that could lead to material decomposition or performance degradation, ensuring full curing while avoiding excessive curing time that could increase energy consumption. For photosensitive polymer materials, ultraviolet light irradiation is used for curing; the irradiation time is adjusted according to the material's photosensitivity and thickness to ensure uniform curing. Through heating or chemical reaction, the polymer material melts and fills the micropores, forming intermolecular bonds with the substrate, ensuring full contact between the material and the substrate during the fusion process and avoiding delamination or voids. The substrate after filling is cleaned or polished to remove excess material that has not been filled into the micropores. Further surface treatment is performed as needed, including applying a protective layer or introducing a functional coating. The tensile strength, elastic modulus, and fracture toughness of the filled structure are tested to ensure its mechanical properties meet design requirements. The conductivity of the filled structure is tested to ensure its conductivity in photovoltaic cell printing. The durability of the structure during long-term use is tested. The filled structure is observed using an optical or electron microscope to check the uniformity and integrity of the micropore filling, ensuring there are no air bubbles or voids. The coefficient of thermal expansion and thermal conductivity of the material are tested to ensure its stability under high-temperature environments. Based on the performance test results, parameters such as substrate treatment, polymer material selection, filling process, and curing conditions are optimized to improve filling quality and product performance. This includes using femtosecond lasers for high-precision positioning and ablation to open windows in the upper and lower printing paste.

[0044] Specifically, step four includes evaluating the mechanical strength, corrosion resistance, and thermal stability of candidate materials; selecting materials for printing screen applications; designing the structure of composite materials to optimize overall performance; improving the bonding force between the substrate and polymer materials through surface treatment; optimizing the microporous structure to improve the strength and flexibility of the materials; optimizing the bonding force at the material interface to improve the durability of the overall structure; regulating the microstructure of the polymer materials to improve their mechanical properties and durability; and optimizing the preparation process parameters to ensure that the material performance reaches its optimal state.

[0045] Selecting a suitable substrate material enhances the strength and durability of the structure. Analyzing material properties, evaluating candidate materials for mechanical strength, corrosion resistance, and thermal stability, and selecting the most suitable material for the printing screen application. Candidate materials include metal substrates (such as nickel and stainless steel) which offer high strength and good conductivity but may lack flexibility; and polymer substrates (such as polyimide and polyester) which offer excellent flexibility and lightweight properties but may have lower strength. Composite substrates, combining the advantages of metals and polymers, such as metal-polymer composites, provide both high strength and flexibility. Selection and validation: Based on the actual application requirements, select the most suitable substrate material and verify its performance through experiments.

[0046] Design the structure of composite materials to optimize overall performance. Multi-layer structure design involves creating a double-layer sandwich structure with different materials for the upper and lower layers to balance strength and flexibility. For example, the upper layer might use a polymer for flexibility, while the lower layer uses a metal for high strength. Interface design incorporates transition layers between different materials to enhance interfacial bonding and prevent delamination or peeling. Experimental verification involves preparing samples and conducting tensile and fatigue tests to validate the effectiveness of the structural design.

[0047] Surface treatment enhances the adhesion between the substrate and the polymer material. Cleaning involves ultrasonic cleaning with solvents such as deionized water, acetone, and ethanol to remove contaminants from the substrate surface. Plasma treatment increases the number of active groups on the substrate surface, improving adhesion to the polymer. Chemical modification introduces chemical functional groups, such as hydroxyl and amino groups, into the substrate surface, strengthening the chemical bond with the polymer. Adhesion verification utilizes tensile or peel tests to evaluate the effectiveness of surface treatment in improving interfacial adhesion.

[0048] Optimizing micropore structures enhances the strength and flexibility of materials. Through experiments and simulations, the optimal micropore size and distribution are determined to balance strength and flexibility. Smaller micropore sizes contribute to increased strength, while larger sizes enhance flexibility. Photolithography is used to fabricate high-precision micropore structures. Electrochemical etching, by controlling etching conditions, achieves a uniform micropore distribution. Laser drilling is suitable for fabricating large or complex-shaped micropores. Performance testing involves preparing samples with different micropore structures and conducting tensile and fatigue tests to evaluate the impact of the structure on material properties.

[0049] Optimizing the interfacial bonding strength improves the overall structural durability. Introducing an interfacial layer, such as nanoparticles or functional coatings, between the substrate and the polymer material enhances interfacial bonding. For example, introducing carbon nanotubes or nanoparticles improves the mechanical strength and conductivity of the interface. Using surfactants reduces interfacial tension and promotes uniform bonding between the polymer material and the substrate. Experimental verification, including tensile and peel tests, evaluates the effect of optimized interfacial bonding on improving material properties.

[0050] Regulating the microstructure of polymer materials improves their mechanical properties and durability. This involves controlling crystallinity by adjusting synthesis conditions or post-processing techniques to enhance strength and durability. During material preparation, methods such as stretching or directional solidification can be used to control the orientation of polymer chains, thereby improving mechanical properties. Adding nanofillers, such as carbon nanotubes and nanoparticles, to polymer materials can improve strength and conductivity. Performance testing involves preparing samples with different microstructures and conducting tensile and conductivity tests to evaluate the impact of microstructure regulation on material properties.

[0051] Optimize preparation process parameters to ensure optimal material performance. Adjust parameters such as electrodeposition current density, electrolyte concentration, and deposition time to optimize the thickness and uniformity of the metal film. Optimize the curing process, including curing temperature and time for the polymer material, to ensure complete curing while preventing performance degradation. Optimize the filling process, including filling methods such as coating, dispensing, and spin coating, to ensure uniform and complete micropore filling. Verify the effect of optimized process parameters on improving material performance through experimental testing.

[0052] A comprehensive evaluation of material performance is conducted to ensure it meets design requirements. Tensile, bending, and fatigue tests are performed to assess mechanical properties such as strength, elastic modulus, and fracture toughness. The material's electrical conductivity is tested to ensure it maintains its conductivity during the printing process. High-temperature, high-humidity, and ultraviolet aging tests are conducted to evaluate the material's durability over long-term use. The microstructure of the material is observed using optical or electron microscopy to check the uniformity and integrity of micropore filling. A comprehensive evaluation is then performed based on the test results to determine whether the material's performance meets design requirements.

[0053] Based on the test results, the material structure design was further optimized. Structural parameters, such as micropore size and interface layer thickness, were adjusted to further improve material performance. Experimental verification was conducted by preparing improved samples and performing performance tests to verify the effectiveness of the structural design improvements.

[0054] Further optimize the microstructure of the material to improve its performance. Based on test results, adjust the crystallinity, orientation, and other microstructures of the polymer material to further improve its mechanical properties and durability. Experimentally verify the optimization by preparing samples with different microstructures, conducting performance tests, and evaluating the optimization effect. Scale up the optimized process to industrial production to ensure product quality and production efficiency. Design and implement an industrial-scale production process based on the optimized process parameters in the laboratory. Establish a rigorous quality control system to ensure consistent performance of each batch of products. Improve production efficiency and reduce costs by optimizing production equipment and processes.

[0055] Verify the material's performance in practical applications to drive market adoption. Use optimized screen printing plates in actual printing processes to verify their strength, print lifespan, and mechanical properties. Collect customer feedback to understand the material's performance and needs in real-world applications. Based on test results and customer feedback, conduct market promotion to expand the product's application scope and market share.

[0056] Through material structure design and microstructure optimization, the strength, printing lifespan, and mechanical properties of solar cell grid printing screens can be effectively improved. Specific steps include substrate material selection, composite material structure design, surface treatment, microporous structure design, interface bonding optimization, and microstructure control of polymer materials. Simultaneously, by combining process optimization, performance testing and verification, structural improvement, and industrial application and promotion, the high efficiency and reliability of the materials in practical applications can be ensured, meeting the requirements of solar cell printing.

[0057] Organize the experimental data and clarify the meaning of each set of data. Assume the experimental data includes the following process parameters and performance indicators: Temperature (°C); Pressure (MPa); Time (minutes); Strength (MPa) Printing life (times); Mechanical properties (such as elastic modulus, GPa); The following is the experimental data: ; The effect of temperature on performance: Strength and temperature: Strength gradually increases from 50 MPa to 70 MPa as the temperature rises from 100℃ to 200℃. Increasing temperature significantly improves strength.

[0058] Print life and temperature: Print life increases and then decreases from 100℃ to 200℃. At 150℃, the print life reaches its peak of 1500 cycles.

[0059] Mechanical properties and temperature: As temperature increases, mechanical properties (elastic modulus) gradually increase, from 2.0 GPa to 2.4 GPa.

[0060] Strength and pressure: At the same temperature and time, the strength increases slightly as the pressure increases from 1 MPa to 2 MPa, such as from Group 1 to Group 3, where the strength increases from 50 MPa to 52 MPa.

[0061] Printing life and pressure: Increased pressure causes fluctuations in printing life, but the overall impact is not significant.

[0062] Mechanical properties and pressure: Increased pressure has a relatively small effect on mechanical properties.

[0063] Intensity and time: Increasing the time from 5 minutes to 10 minutes increased the intensity, but only slightly.

[0064] Printing lifespan and time: As time increases, the overall printing lifespan shows an upward trend.

[0065] Mechanical properties and time: Mechanical properties improve slightly with increasing time.

[0066] Data analysis identifies the key parameters most significantly impacting performance indicators: Strength: Temperature is the primary influencing factor, while pressure and time have less impact. Print life: Temperature and time are the primary influencing factors, while pressure has less impact. Mechanical properties: Temperature is the primary influencing factor, while pressure and time have less impact.

[0067] To achieve optimal strength and mechanical properties, it is recommended to maintain the temperature at around 150℃. To extend print life, a slightly lower temperature can be considered, but a trade-off between strength and mechanical properties must be struck. Appropriately extending the processing time (e.g., from 5 minutes to 10 minutes) can improve both strength and print life. Pressure has a relatively minor impact on performance; an appropriate pressure range can be selected based on the actual equipment conditions.

[0068] Temperature is a key parameter affecting strength, print life, and mechanical properties. Time has a significant impact on performance indicators; appropriately extending the processing time helps improve performance. Pressure has a relatively small impact on performance and can be adjusted flexibly according to equipment conditions. Based on the above analysis, it is recommended to control the temperature at around 150℃ in actual processing, appropriately extend the processing time, and select a suitable pressure range according to equipment conditions to obtain optimal performance indicators.

[0069] In the processing technology of the embedded metal polymer flexible composite meshless screen printing stencil for photovoltaic cell printing, the embedded metal polymer flexible composite meshless screen printing stencil is prepared by using a non-silicon semiconductor electrochemical additive micro-nano mechanical manufacturing process. The stencil has a micro-electroformed metal film with patterned through holes and acts as a skeleton. A non-curing organic polymer liquid material of the same material is injected into specific through holes of the metal film using a precision CNC injection process, and after semi-curing, anchoring columns are formed that are connected vertically. The flow or semi-flow characteristics of the non-curing organic polymer and vacuum negative pressure are used to fill micropores and coat the anchoring columns and the metal film to form an embedded metal polymer structure. Finally, the anchoring columns and the metal film are connected by full curing fusion, and femtosecond laser windowing is performed on specific patterned areas to form the embedded metal polymer flexible composite meshless printing stencil. Overall, the mechanical strength and printing lifespan of the solar grid printing screen products are improved through material structure design and microstructure optimization. While ensuring the overall strength and elastic modulus of the composite film layer, the product qualification rate is also greatly improved. At the same time, while the service life of individual printing screens is improved, the stability of the service life of the overall batch of printing screens is also more stable, as shown by statistical data analysis.

[0070] Example 2 Metal film fabrication: Using E-Fab (photolithography electroforming microfabrication) non-silicon process, nickel or nickel alloy electroformed films with specific patterns of anchored micro-vias and printing slurry through-holes are manufactured.

[0071] Equipment: Custom-made precision electroforming equipment with current accuracy at the milliampere level. It is a customized coating equipment that has been partially upgraded and improved based on the advanced semiconductor board-level packaging wet coating machine.

[0072] Operation: In a wet thin film electrodeposition tank equipped with a soluble anode and a metallized glass carrier cathode (workpiece) with a uniform flow field design, the rectifier of the equipment is adjusted to apply a working voltage between the anode and cathode. The metal cations in the electrolyte are reduced and deposited on the conductive seed layer that is not blocked by the ultraviolet exposure photolithography process on the cathode (workpiece) to form a nickel metal or nickel alloy metal film. The anode dissolves under the action of the electric field to provide metal cations. The thickness is obtained by adding current density and time.

[0073] Equipment parameters: Commonly used equipment operating parameters are as follows: voltage between 1.0V and 3.5V, electroforming current density between 0.5 and 3.0 ASD, temperature between 30°C and 50°C, pH value between 3.2 and 4.2, time between 40 and 140 minutes depending on the thickness of the workpiece, and electrolyte circulation and filtration parameters between 3.0L / min and 100L / min depending on the size of the workpiece.

[0074] A2. Soft organic film lamination, such as PI film (polyimide film): A cured organic polymer material with a thin layer of adhesive, such as PI film layer (polyimide film layer), is laminated under the metal film.

[0075] Equipment: Hot press laminating machine.

[0076] Operation: Preheat the machine for at least 10 minutes according to the ambient temperature. Place the clean and dried metal film layer onto the clamping platform of the cleaned laminating machine. Then, apply the cured organic polymer material, such as polyimide film, to the specific pattern area on the metal film layer, aligning it in position. Control the clamping platform push cylinder control button to bring the metal and organic polymer film without hot pressing lamination into the hot pressing clamping area of ​​the laminating machine. Slowly move the preheated heating mold pressure head fixture downwards until it presses the metal and cured organic polymer material, such as polyimide film, together. The softened cured organic polymer material, such as polyimide film, will then adhere tightly to the metal film layer.

[0077] Equipment parameters: Preheat for at least 10 minutes based on ambient temperature to ensure the pressure head fixture reaches the preset temperature, such as 180 degrees Celsius; platform parameters: 600mm*600mm, with positioning scales engraved on the platform; transmission cylinder pressure adjustable between 0.2MPa and 0.8MPa; applied downward pressure adjustable between 15000 Newtons and 2000 Newtons; bonding time: 1 minute.

[0078] A3. Hot pressing: Hot pressing of a double-layer metal-polymer composite film after heat treatment.

[0079] Equipment: Hot press laminating machine.

[0080] Operation: Preheat the machine for more than 10 minutes according to the ambient temperature, and then maintain the temperature at the set value. Continue to heat-treat the softened composite solidified organic polymer material, such as polyimide film, under pressure to form a bond with mechanical and van der Waals forces. After cooling, remove the film for the next step.

[0081] Equipment parameters: Preheat the machine for at least 10 minutes to reach 180 degrees Celsius based on the ambient temperature, and maintain the temperature of the pressure head fixture at the preset value, such as 190 degrees Celsius; apply downward pressure between 2500 Newtons and 4000 Newtons, and adjust the hot pressing time to about 2 to 5 minutes.

[0082] A4. Injection: Injecting the anchoring micropores of the metal-polymer composite film into the non-curing organic polymer material (PI).

[0083] Equipment: CNC dispensing machine.

[0084] Operation: A4.1 Start the equipment and enter working state, select single-point quantitative dispensing mode; A4.2 Input graphic file: After editing outside the machine, upload the graphic file to be dispensed to the dispensing machine controller in a general vector format; A4.3 Fill glue: Fill the glue tank with liquid prepolymer polyimide material below the upper limit, fix the glue tank, and install the pressure piston; A4.4 Determine dispensing parameters: starting point coordinates, needle height, single dispensing volume (needle diameter, constant glue supply pressure, dispensing time), needle lifting plane movement and vertical axis return needle movement speed, etc.; A4.5 Adjust the target point: Adjust the target point in the graphic file and the equipment positioning point to coincide or be concentric; A4.6 Place the plate to be dispensed, align it with the scale line of the equipment plate, observe the CCD (alignment camera) image, align the physical target with the graphic target, and press the button to start dispensing.

[0085] Equipment parameters: Glue tank insulation temperature setting: 40 degrees Celsius; Glue tank supply pressure adjustment between 3 kPa and 5 kPa; Planar two-dimensional movement speed setting: 400 mm / s to 600 mm / s; Vertical axis lifting speed setting: 400 mm / s; Needle lifting height: 1 mm when dispensing glue, 5 mm when retracting needle; Glue dispensing volume: selectable between 0.024 seconds and 0.036 seconds.

[0086] A5. Vacuum degassing: Vacuum degassing and tight bonding treatment is performed on non-cured organic prepolymer materials (such as PI prepolymer, i.e., polyimide prepolymer) injected into blind holes.

[0087] Equipment: Vacuum degassing equipment.

[0088] Operation: Close the vacuum extraction valve and open the vacuum breaking valve; open the vacuum chamber door; carefully place the semi-finished product to be processed flat on the vacuum chamber platform; close the vacuum chamber door and close the vacuum breaking valve; open the vacuum extraction valve and observe that the vacuum gauge in the chamber is working normally and the vacuum degree is rising; when the vacuum degree reaches or exceeds the set value, maintain it for the set time and then close the vacuum extraction valve; open the vacuum breaking valve, and when the vacuum gauge returns to zero, open the vacuum chamber door, move and remove the processed semi-finished product, close the vacuum breaking valve, and close the vacuum chamber door.

[0089] Equipment parameters: Vacuum threshold: -100KPa; Post-vacuum treatment time: approximately 150 to 300 minutes; Relative humidity inside the vacuum chamber: below 55%; Vacuum breaking gas: CDA (clean, dry compressed air) or dry compressed nitrogen.

[0090] A6. Semi-cured: Semi-cured treatment of non-cured organic prepolymer materials (such as PI prepolymer, i.e., polyimide prepolymer) that have been filled with blind holes.

[0091] Equipment: Vacuum curing oven.

[0092] Operation: A6.1 Preheat the machine for at least 10 minutes based on the ambient temperature until the preset temperature is reached. Quickly place the defoamed semi-finished product into the vacuum curing oven, close the oven door, set the initial vacuum level, and start vacuuming. Introduce nitrogen for at least 5 minutes to reach the preset temperature again. Perform semi-curing pretreatment under nitrogen atmosphere according to the pre-curing temperature rise curve. A6.2 Reduce the nitrogen inlet valve and control the nitrogen flow rate to below 2 sccm (cubic centimeters per minute) during the intermediate stage. A6.3 Start vacuuming. Once the vacuum reaches the set value, perform vacuum semi-curing treatment under this vacuum condition according to the semi-curing heat treatment temperature rise curve. A6.4 Turn off heating, adjust the vacuum setting, increase the nitrogen flow rate, wait for the oven temperature to drop to 50 degrees Celsius, close the vacuum extraction valve and nitrogen inlet valve, release the vacuum, open the oven door, and remove the processed workpiece.

[0093] Equipment parameters: Initial preset temperature 50 degrees Celsius; Initial vacuum setting: -10 kPa; Initial nitrogen flow rate: 80-120 sccm (cubic centimeters per minute); Pre-curing temperature and time parameters: from 50 degrees Celsius to 90 degrees Celsius, temperature rise rate 3-5 degrees Celsius per minute, holding time at 90 degrees Celsius for 90 minutes; from 90 degrees Celsius to 125 degrees Celsius, temperature rise rate 5-8 degrees Celsius per minute, holding time at 125 degrees Celsius for 90 minutes; Intermediate nitrogen flow rate adjusted to below 2 sccm (cubic centimeters per minute); Pre-curing heat treatment vacuum setting: -60 kPa (cubic centimeters per minute). (Cartridge); Semi-curing temperature and time parameters: 125°C to 180°C, temperature rise rate 2-4°C / min, 180°C holding time 90 minutes; 180°C to 250°C, temperature rise rate 2-4°C / min, 250°C holding time 90 minutes; 250°C to 320°C, temperature rise rate 2-4°C / min, 320°C holding time 120 minutes; Vacuum setting for cooling in the later stage of semi-curing: -20 kPa; Nitrogen flow rate setting for cooling in the later stage of semi-curing: nitrogen flow rate 40-60 sccm (cubic centimeters per minute).

[0094] A7. PI film lamination: Lay the cured organic polymer PI film layer onto the semi-cured double-layer metal-polymer composite film with micro-bumps after the blind holes are filled.

[0095] Equipment: Hot press laminating machine.

[0096] Operation: Preheat the machine for at least 10 minutes based on the ambient temperature. Place the semi-cured metal-polymer double film layer onto the cleaned clamping platform of the laminating machine. Then, apply the cured organic polymer material, such as polyimide film, to the specific pattern area on the side with the metal film layer, aligning it in position. Control the clamping platform push cylinder control button to bring the metal and organic polymer film without hot pressing into the hot pressing clamping area of ​​the laminating machine. Slowly move the preheated heating mold pressure head fixture downwards until it presses the metal and cured organic polymer material, such as polyimide film, together. The softened cured organic polymer material, such as polyimide film, will then adhere tightly to the metal film layer.

[0097] Equipment parameters: Preheat the machine for at least 10 minutes based on the ambient temperature to allow the pressure head fixture temperature to reach the preset value, such as 180 degrees Celsius; platform parameters: 600mm*600mm, with positioning scales engraved on the platform; transmission cylinder pressure is adjustable between 0.2MPa and 0.8MPa; applied downward pressure is adjustable between 15000 Newtons and 2000 Newtons; bonding time: 3 minutes.

[0098] A8. Leveling: The three-layer uneven metal-polymer composite film with micro-bumps and anchoring posts is subjected to leveling heat treatment.

[0099] Equipment: Hot press laminating machine.

[0100] Operation: Preheat the machine for more than 10 minutes according to the ambient temperature, and then maintain the temperature at the set value. Continue to heat-treat the softened and cured organic polymer material, such as polyimide film, under pressure. Perform leveling and pressing heat treatment on the three-layer uneven metal polymer composite film composed of micro-bumps and anchoring posts to form a bonding force with mechanical and van der Waals force levels. After cooling, remove it for the next step of processing.

[0101] Equipment parameters: Preheat the machine for at least 10 minutes to reach 180 degrees Celsius based on the ambient temperature, and maintain the temperature of the pressure head fixture at the preset value, such as 190 degrees Celsius; apply downward pressure in the range of 2500 Newtons and 4000 Newtons, and adjust the hot pressing time to about 4 to 6 minutes.

[0102] A9. Curing: The three-layer flat metal polymer semi-cured composite film with anchor posts is subjected to curing heat treatment.

[0103] Equipment: Vacuum curing oven.

[0104] Operation: A9.1 Preheat the machine for at least 10 minutes based on the ambient temperature until the preset temperature is reached. Quickly place the leveled and pressed three-layer flat metal polymer composite film semi-finished product with anchor posts and porous upper and lower clamps into the vacuum curing oven. Close the oven door, set the initial vacuum level, and start vacuuming. Introduce nitrogen gas in the initial stage for at least 5 minutes to allow the oven temperature to reach the preset temperature again. A9.2 Close the nitrogen flow valve, adjust the vacuum level to the mid-stage vacuum level, and immediately open the nitrogen inlet valve. Adjust the nitrogen inlet flow valve to the mid-stage nitrogen inlet flow rate setting. A9.3 After the temperature / vacuum level has stabilized for 3 minutes, perform curing treatment under a vacuum nitrogen atmosphere according to the curing temperature rise curve. A9.4 Turn off heating, adjust the final vacuum level, increase the nitrogen flow rate to the final setting, wait for the oven temperature to drop to 50 degrees Celsius, close the vacuum extraction valve and nitrogen inlet valve, release the vacuum, open the oven door, and remove the processed workpiece.

[0105] Equipment parameters: Initial preset temperature 50 degrees Celsius; Front-end vacuum setting: -20 kPa; Front-end nitrogen flow rate: 80-120 sccm (cubic centimeters per minute); Mid-curing stage vacuum setting: -60 kPa; Mid-curing stage nitrogen flow rate adjusted to 4-6 sccm (cubic centimeters per minute); Curing temperature and time parameters: From 50 degrees Celsius to 180 degrees Celsius, temperature rise rate 2-4 degrees Celsius per minute; Holding time at 180 degrees Celsius for 30 minutes; From 180 degrees Celsius to 250 degrees Celsius, temperature rise rate 2- Temperature rise rate: 4 degrees Celsius per minute; holding time: 40 minutes at 250 degrees Celsius; temperature rise rate: 2-4 degrees Celsius per minute from 250 degrees Celsius to 320 degrees Celsius; holding time: 40 minutes at 320 degrees Celsius; temperature rise rate: 2-4 degrees Celsius per minute from 320 degrees Celsius to 360 degrees Celsius; holding time: 120 minutes at 360 degrees Celsius; cooling time: 60 minutes at 300 degrees Celsius; vacuum setting for cooling after curing: -20 kPa; nitrogen flow rate setting for cooling after curing: 40-60 sccm (cubic centimeters per minute).

[0106] A10. Laser patterned windowing: A femtosecond laser ablates the metal film layer through holes, and an organic polymer film covering the holes is used to create patterns with specific design requirements for printing.

[0107] Equipment: Femtosecond laser engraving machine.

[0108] Operation: A10.1 Place the sandwich-embedded metal-polymer composite seamless screen printing plate (which requires windowing) at a specific position on the porous ceramic vacuum chuck of the femtosecond laser engraving machine. Adjust the relative position of the target on the uploaded screen printing plate vector image and the actual target displayed on the femtosecond laser engraving machine's CCD (charge-coupled device camera) to ensure the target centers coincide, and activate vacuum adsorption. A10.2 Set the adjustable parameters of the femtosecond laser engraving machine. A10.3 Run the laser cutting operation. A10.4 Release the vacuum and remove the workpiece after the laser cutting operation is completed. A10.5 Flip the workpiece over and adjust the relative position of the target on the uploaded screen printing plate vector image and the actual target displayed on the femtosecond laser engraving machine's CCD (charge-coupled device camera) to ensure the target centers coincide, and activate vacuum adsorption. A10.6 Check the composite and fine-tune the adjustable parameters of the femtosecond laser engraving machine. A10.7 Run the laser cutting operation a second time. A10.8 Release the vacuum and remove the workpiece after the laser cutting operation is completed.

[0109] Equipment parameters: Femtosecond cutting center wavelength selection 520 nm; focal spot 2.1 μm; integrated laser pulse width minimum 45 femtoseconds; single pulse energy selectable: 3 μJ, 5 μJ, 8 μJ, 11 μJ, 20 μJ, 35 μJ, maximum single pulse energy; laser scanning speed: 1 mm / s to 600 mm / s; repetition frequency: 1 Hz to 2 MHz.

[0110] Example 3 B1. Fabrication of metal films: Manufacturing nickel or nickel alloy electroformed films with specific patterns of anchored micro-vias and printing slurry vias using E-Fab (photolithography electroforming microfabrication) non-silicon processes.

[0111] Equipment: Custom-made precision electroforming equipment with current accuracy at the milliampere level. It is a customized coating equipment that has been partially upgraded and improved based on the advanced semiconductor board-level packaging wet coating machine.

[0112] Operation: In a wet thin film electrodeposition tank equipped with a soluble anode and a metallized glass carrier cathode (workpiece) with a uniform flow field design, the rectifier of the equipment is adjusted to apply a working voltage between the anode and cathode. The metal cations in the electrolyte are reduced and deposited on the conductive seed layer that is not blocked by the ultraviolet exposure photolithography process on the cathode (workpiece) to form a nickel metal or nickel alloy metal film. The anode dissolves under the action of the electric field to provide metal cations. The thickness is obtained by adding current density and time.

[0113] Equipment parameters: Commonly used equipment operating parameters are as follows: voltage between 1.0V and 3.5V, current density between 0.5 and 3.0ASD, temperature between 30°C and 50°C, pH value between 3.2 and 4.2, time between 40 and 140 minutes depending on the thickness of the workpiece, and electrolyte circulation filtration parameters between 3.0L / min and 100L / min depending on the size of the workpiece area.

[0114] B2. Lower baffle film bonding: A temporary heterogeneous baffle film is bonded under the metal diaphragm.

[0115] Equipment: Hot press laminating machine.

[0116] Operation: Preheat the machine for at least 10 minutes based on the ambient temperature. Place the cleaned and dried metal film layer onto the clamping platform of the cleaned laminating machine. Then, apply a heterogeneous organic polymer film, such as a PFA film (the chemical name of PFA film is a copolymer of perfluoropropyl perfluorovinyl ether and polytetrafluoroethylene), to the specific pattern area on the metal film layer, aligning it in position. Control the clamping platform push cylinder control button to bring the metal and the heterogeneous organic polymer film, such as the PFA film, into the hot press clamping area of ​​the laminating machine. Slowly move the preheated heating mold pressure head fixture downwards until the metal and the heterogeneous organic polymer film, such as the PFA film, are in close contact with the metal film layer, achieving a temporary bonding effect.

[0117] Equipment parameters: Preheat the machine for at least 10 minutes based on the ambient temperature to allow the pressure head fixture temperature to reach the preset value, such as 200 degrees Celsius; platform parameters: 600mm*600mm, with positioning scales engraved on the platform; transmission cylinder pressure is adjustable between 0.2MPa and 0.8MPa; applied downward pressure is adjustable between 15000 Newtons and 2000 Newtons; bonding time: 3 minutes.

[0118] B3. Injection: Injecting the anchoring micropores of the metal-polymer composite film into the non-curing organic polymer material (PI).

[0119] Equipment: CNC dispensing machine.

[0120] Operation: B3.1 Start the equipment and enter working state, select single-point quantitative dispensing mode; B3.2 Input graphic file: After editing outside the machine, upload the graphic file to be dispensed to the dispensing machine controller in a general vector format; B3.3 Fill glue: Fill the glue tank with liquid polyimide material below the upper limit, fix the glue tank, and install the pressure piston; B3.4 Determine dispensing parameters: starting point coordinates, needle height, single dispensing volume (needle diameter, constant glue supply pressure, dispensing time), needle lifting plane movement and vertical axis return needle movement speed, etc.; B3.5 Adjust the target point: Adjust the target point in the graphic file and the equipment positioning point to coincide or be concentric; B3.6 Place the plate to be dispensed, align it with the scale line of the equipment plate, observe the CCD (alignment camera) image, align the physical target with the graphic target, and press the button to start dispensing.

[0121] Equipment parameters: Glue tank insulation temperature setting: 40 degrees Celsius; Glue tank supply pressure adjustment between 3 kPa and 5 kPa; Planar two-dimensional movement speed setting: 400 mm / s to 600 mm / s; Vertical axis lifting speed setting: 400 mm / s; Needle lifting height: 1 mm when dispensing glue, 5 mm when retracting needle; Glue dispensing volume: selectable between 0.024 seconds and 0.036 seconds.

[0122] B4. Vacuum degassing: Vacuum degassing and tight bonding treatment is performed on non-cured organic polymer materials (such as PI, i.e., polyimide film) injected into blind holes.

[0123] Equipment: Vacuum degassing equipment.

[0124] Operation: Close the vacuum extraction valve and open the vacuum breaking valve; open the vacuum chamber door; carefully place the semi-finished product to be processed flat on the vacuum chamber platform; close the vacuum chamber door and close the vacuum breaking valve; open the vacuum extraction valve and observe that the vacuum gauge in the chamber is working normally and the vacuum degree is rising; when the vacuum degree reaches or exceeds the set value, maintain it for the set time and then close the vacuum extraction valve; open the vacuum breaking valve, and when the vacuum gauge returns to zero, open the vacuum chamber door, move and remove the processed semi-finished product, close the vacuum breaking valve, and close the vacuum chamber door.

[0125] Equipment parameters: Vacuum threshold: -100KPa; Post-vacuum treatment time: approximately 150 to 300 minutes; Relative humidity inside the vacuum chamber: below 55%; Vacuum breaking gas: CDA (clean, dry compressed air) or dry compressed nitrogen.

[0126] B5. Semi-cured: Semi-cured treatment of non-cured organic polymer materials (such as PI, i.e., polyimide) that have been filled with blind holes.

[0127] Equipment: Vacuum curing oven.

[0128] Operation: B5.1 Preheat the machine for at least 10 minutes based on the ambient temperature until the preset temperature is reached. Quickly place the defoamed semi-finished product into the vacuum curing oven, close the oven door, set the initial vacuum level, and start vacuuming. Introduce nitrogen for at least 5 minutes to reach the preset temperature again. Perform semi-curing pretreatment under nitrogen atmosphere according to the pre-curing temperature rise curve. B5.2 Reduce the nitrogen inlet valve and control the nitrogen flow rate to below 2 sccm (cubic centimeters per minute) during the intermediate stage. B5.3 Start vacuuming. Once the vacuum reaches the set value, perform vacuum semi-curing treatment under this vacuum condition according to the semi-curing heat treatment temperature rise curve. B5.4 Turn off heating, adjust the vacuum setting, increase the nitrogen flow rate, wait for the oven temperature to drop to 50 degrees Celsius, close the vacuum extraction valve and nitrogen inlet valve, release the vacuum, open the oven door, and remove the processed workpiece.

[0129] Equipment parameters: Initial preset temperature 50 degrees Celsius; Initial vacuum setting: -10 kPa; Initial nitrogen flow rate: 80-120 sccm (cubic centimeters per minute); Pre-curing temperature and time parameters: from 50 degrees Celsius to 90 degrees Celsius, temperature rise rate 3-5 degrees Celsius per minute, holding time at 90 degrees Celsius for 90 minutes; from 90 degrees Celsius to 125 degrees Celsius, temperature rise rate 5-8 degrees Celsius per minute, holding time at 125 degrees Celsius for 90 minutes; Intermediate nitrogen flow rate adjusted to below 2 sccm (cubic centimeters per minute); Pre-curing heat treatment vacuum setting: -60 kPa (cubic centimeters per minute). (Cartridge); Semi-curing temperature and time parameters: 125°C to 180°C, temperature rise rate 2-4°C / min, 180°C holding time 90 minutes; 180°C to 250°C, temperature rise rate 2-4°C / min, 250°C holding time 90 minutes; 250°C to 320°C, temperature rise rate 2-4°C / min, 320°C holding time 120 minutes; Vacuum setting for cooling in the later stage of semi-curing: -20 kPa; Nitrogen flow rate setting for cooling in the later stage of semi-curing: nitrogen flow rate 40-60 sccm (cubic centimeters per minute).

[0130] B6. Lower membrane peeling: Equipment: Film applicator / hot plate / film release machine / UV lamp; Operation: Apply a single-sided UV anti-adhesion film to the non-bottom-side surface of the semi-finished product with the bottom-side film; after applying the anti-adhesion film, place the film on a preheated hot plate for a period of time, with the bottom-side film firmly attached to the hot plate; after the treatment time is reached, immediately place the hot semi-finished product on a specific position on the lower plate of the film release machine using anti-scalding protective gear; simultaneously, operate the upper plate to press and tighten the anti-adhesion film surface, and then activate the lower plate vacuum adsorption; when the vacuum degree of both the upper and lower adsorption plates reaches the preset value, slowly lift the upper adsorption plate to separate the heterogeneous film with weaker adhesion to the metal film from the metal film; place the metal film with the anti-adhesion film and anchored post after peeling under a UV lamp for a period of time to cause the UV anti-adhesion film to lose adhesion, achieving the purpose of separating the metal film from the anti-adhesion film.

[0131] Equipment parameters: laminating machine, lamination pressure adjustable between 0-0.5MPa; hot plate temperature setting: 150±10 degrees Celsius; vacuum pressure setting: -100Kpa; peeling machine lifting to a 45-degree angle takes less than 10 seconds; UV lamp full-area irradiation time is between 10 seconds and 5 minutes.

[0132] B7. Film Application: Apply PI photosensitive film to both the top and bottom: Equipment: Vacuum laminating machine; Operation: B7.1 Check the dry film holder to ensure the dry film length is sufficient, and ensure the dry film guide and carrier film guide shafts are normal and properly connected; B7.2 Check or reset the parameter settings for each section of the laminator; B7.3 After heating, vacuum, and other settings reach normal, select the program under the parameter number or current confirmation number, and press the start or automatic button to start the automatic lamination; B7.4 Remove the workpieces with the automatically laminated upper and lower films.

[0133] Equipment parameters: Edge margin setting, 0-15mm; Hot press roller temperature setting, between 100°C and 120°C depending on the dry film material requirements; Conveying speed, 1 m / min to 5 m / min; Hot press roller pressure setting, 3 kPa to 5 kPa.

[0134] B8. Double-sided exposure: Equipment: Laser direct writing exposure machine Operation: B8.1 Power on the laser direct-write exposure machine and upload a qualified vector graphics file or call a previously used graphics file program for this device; B8.2 Start the software, add an exposure task, and set or call the exposure process parameters of the exposure machine; B8.3 Place the workpiece to be exposed, dry film side up, on the exposure table of the exposure machine, and perform fine alignment or fine adjustment according to the calibrated position. For overlay workpieces, add fine adjustment of the overlay target alignment position; B8.4 After confirming that the workpiece is aligned with the marked position on the platform, press the vacuum button to hold the workpiece to be processed; B8.5 Load the workpiece to be processed, and the equipment will automatically focus and find the center point or specific target; B8.6 Click Exposure; B8.7 After exposure is complete, unload the workpiece, release the vacuum, and remove the workpiece. Then flip the workpiece over for exposure on the other side. During operation, pay attention to the mirror transformation of the pattern and realignment of the target.

[0135] Equipment parameters: Exposure band: i-line; Exposure dose: 150 millijoules per square centimeter; Exposure time: 30-50 seconds; Vacuum degree: -80 kPa.

[0136] B9. Development: Equipment: Developing machine; Operation: B9.1 Confirm equipment status and set equipment parameters before development; B9.2 Manually load film or automatically load film using a robotic arm; B9.3 Start development; B9.4 After spraying with developing solution, wash with water, dry, and collect the film.

[0137] Equipment parameters: Developing time: 60-140 seconds; Developing temperature: 22-30 degrees Celsius; Developing jet pressure: 0.1-0.25 MPa; Cleaning time: 30-80 seconds; Cleaning temperature: 30-50 degrees Celsius; Cleaning jet pressure: 0.15-0.30 MPa; Drying temperature: 30-90 degrees Celsius; Drying time: 30-100 seconds.

[0138] B10. Imidification curing: Equipment: Vacuum curing oven; Operation: B10.1 Pre-baking: Preheat the machine for at least 10 minutes according to the ambient temperature until the preset pre-baking temperature is reached. Open the oven door and place the uncured (uniminated) composite film, which has been developed, cleaned, and dried, into the vacuum curing oven. Close the oven door, set the pre-baking vacuum setting, turn on the vacuum pump, and purge with nitrogen for at least 5 minutes to reach the preset temperature again. Perform pre-baking treatment under a nitrogen atmosphere according to the pre-baking temperature rise curve. B10.2 Imination curing: Reduce the nitrogen inlet valve and control the nitrogen flow rate for imination curing to below 2 sccm (cubic centimeters per minute). B10.3 Turn on the vacuum pump. Once the vacuum reaches the set value, perform vacuum imination curing treatment under this vacuum condition according to the imination curing temperature rise curve. B10.4 Cooling: Turn off the heating, adjust the vacuum setting, increase the nitrogen flow rate, wait for the oven temperature to drop to 50 degrees Celsius, close the vacuum extraction valve and the nitrogen inlet valve, release the vacuum, open the oven door, and remove the processed workpiece.

[0139] Equipment parameters: Pre-baking stage temperature setting: 50 degrees Celsius; Pre-baking stage vacuum setting: -10 kPa; Pre-baking nitrogen flow rate: 80-120 sccm (cubic centimeters per minute); Pre-baking treatment temperature and time parameters: from 50 degrees Celsius to 90 degrees Celsius, temperature rise rate: 3-5 degrees Celsius per minute; holding time at 90 degrees Celsius: 90 minutes; from 90 degrees Celsius to 125 degrees Celsius, temperature rise rate: 5-8 degrees Celsius per minute; holding time at 125 degrees Celsius: 90 minutes; Imidification curing stage nitrogen inlet flow rate adjusted to below 2 sccm (cubic centimeters per minute); Imidification curing vacuum setting: -60 kPa. KPa (kilopascal); Imidification curing temperature and time parameters: 125°C to 180°C, temperature rise rate 2-4°C / min, 180°C holding time 90 minutes; 180°C to 250°C, temperature rise rate 2-4°C / min, 250°C holding time 90 minutes; 250°C to 320°C, temperature rise rate 2-4°C / min, 320°C holding time 120 minutes; Cooling stage vacuum setting: -20 kPa (kilopascal); Cooling stage nitrogen flow rate setting: nitrogen flow rate 40-60 sccm (cubic centimeters per minute).

[0140] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0141] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A processing technology for an embedded metal-polymer flexible composite meshless screen printing plate for photovoltaic cell printing, characterized in that, include: Step 1: The skeleton of the embedded metal polymer composite meshless screen and the micro-electroformed metal film with through-hole pattern are prepared by non-silicon semiconductor electrochemical additive micro-nano mechanical manufacturing process; Step 2: Using a precision CNC injection process, inject a semi-cured organic polymer liquid material of the same material to form an anchoring column with interconnected upper and lower sections. Step 3: Using the flow or semi-flow properties of non-curing organic polymers and vacuum negative pressure, a micropore filling coating process is used to connect the anchoring post and the metal film to form an embedded metal polymer structure. Step 4: The anchoring posts and the metal film are connected by full curing fusion, and femtosecond laser windowing is performed on specific graphic areas to form an embedded metal polymer flexible composite screen printing plate without mesh nodes.

2. The processing technology for an embedded metal-polymer flexible composite meshless screen printing plate for photovoltaic cell printing according to claim 1, characterized in that, Step one includes generating a patterned mask using computer-aided design tools based on the structural design of the target solar grid printing screen. Glass is selected as the carrier plate to ensure the flatness and stability of the subsequent film layer. The carrier plate is cleaned and surface treated to remove surface contaminants and ensure that its surface is clean and smooth. Using semiconductor electrochemical additive microfabrication technology, a metal film with a specific design pattern is micro-electrocast onto a glass substrate after being coated with a flexible material and metallized. The self-supporting patterned metal film after peeling is used as the metal film layer of the skeleton in the embedded structure. In the through-holes of the upper and lower structures of the metal thin film, an uncured organic polymer material is filled into the through-holes using a dispensing process. The filled semi-preform is heat-treated to transform it into a semi-cured state.

3. The process for processing an embedded metal-polymer flexible composite meshless screen printing plate for photovoltaic cell printing according to claim 1, characterized in that, Step one includes selecting a carrier plate material, cleaning and surface treating the carrier plate; selecting a flexible substrate material, designing a metallization seed layer nanoscale metal film system on the substrate material, forming a conductive nanofilm by physical vapor deposition, coating the conductive nanofilm surface with photoresist according to design specifications, and exposing and developing the photoresist with a specific design pattern. Then, the entire assembly material is placed in an electrolyte containing metal ions, and electrochemical additive deposition is performed on the exposed conductive nanofilm area. This electrochemically deposited metal film with a specific design pattern becomes a micro-electroformed self-supporting metal film after being peeled off. Polymer materials are introduced into the upper and lower layers of the metal film and at specific opening locations. The introduced polymer materials are cured to ensure a tight bond between the metal film and the polymer materials. Through curing modification methods, the bonding force between the metal film and the polymer materials is enhanced to prevent delamination or peeling. The prepared embedded metal polymer structure is tested for mechanical strength, mechanical deformation, interface bonding state, wet weight of printed grid lines, and grid line morphology.

4. The process for processing an embedded metal-polymer flexible composite meshless screen printing plate for photovoltaic cell printing according to claim 1, characterized in that, Step two includes determining the current density applied during electrodeposition to control the deposition rate and uniformity of the metal thin film, calculated as follows: , Where J is the current density, I is the deposition current, and A is the electrode area; Ensure the concentration and pH of the metal ions in the electrolyte are suitable for the electrodeposition process, and calculate the deposition time to obtain the required metal film thickness, as follows: ， Where t is the deposition time, d is the film thickness, A is the electrode surface area, J is the current density, and ρ is the metal density; Determine the curing temperature and time of the polymer material to ensure good bonding with the metal film. The curing temperature is determined based on the glass transition temperature of the material, and the curing time is 1–3 hours. The interfacial bonding strength between the polymer material and the metal film in the upper and lower double-layer sandwich structure was evaluated and calculated as follows: , Where σ is the interfacial bonding strength, F is the tensile force, and A is the test area.

5. The processing technology for an embedded metal-polymer flexible composite meshless screen printing plate for photovoltaic cell printing according to claim 1, characterized in that, Step two includes selecting polymer materials according to process requirements, considering the material's melting point, viscosity, thermal stability, especially curing characteristics, as well as the mechanical properties after curing. Suitable liquid polymer raw materials of the same material and precision digital control dispensing equipment are selected to accurately inject the liquid polymer material into specific through-holes of the metal film. The liquid polymer material has good fluidity, which facilitates filling and spreading, ensuring that the material is filled evenly and in equal amounts during the filling process, reducing blockages or voids. In addition, a vacuum evacuation process is added to ensure that refilling is carried out in a vacuum environment. Negative pressure is used to accelerate the filling of material into the micropores and eliminate microbubbles. Then, the workpiece with the through-holes filled and the substrate are placed in an oven to semi-cur the material according to the curing curve.

6. The process for processing an embedded metal-polymer flexible composite meshless screen printing plate for photovoltaic cell printing according to claim 5, characterized in that, Step four also includes setting a suitable full-curing temperature based on the thermal properties of the material to avoid overheating that could lead to material decomposition or performance degradation, ensuring that the material is fully cured and formed, while avoiding excessive curing time that could increase energy consumption. For photosensitive polymer materials, ultraviolet light is used to directly pattern and cure them. The irradiation time is adjusted according to the photosensitivity and thickness of the material to ensure uniform curing. The polymer material is further melted and bonded to the anchor post by pressurizing, heating, softening, and fusion bonding, and then tightly adhered to the metal film. The upper and lower polymer film layers form intermolecular bonds with the anchor post, ensuring that the material and the metal film are in full contact and mechanically embedded during the fusion process, avoiding delamination or voids. Based on the performance test results, optimize parameters such as substrate treatment, polymer material selection, filling process, and curing conditions to improve filling quality and product performance.

7. The process for processing an embedded metal-polymer flexible composite meshless screen printing plate for photovoltaic cell printing according to claim 6, characterized in that, Step four includes evaluating the mechanical strength, corrosion resistance, and thermal stability of candidate materials; selecting materials for printing screen applications; designing the structure of composite materials to optimize overall performance; improving the bonding force between the substrate and polymer materials through surface treatment; optimizing the microporous structure to improve the strength and flexibility of the materials; optimizing the bonding force at the material interface to improve the durability of the overall structure; regulating the microstructure of the polymer materials to improve their mechanical properties and durability; and optimizing the preparation process parameters to ensure that the material performance reaches its optimal state.

8. The process for processing an embedded metal-polymer flexible composite meshless screen printing plate for photovoltaic cell printing according to claim 7, characterized in that, In step two, a dispensing process is used to place the uncured organic polymer material into specific upper and lower structural through-holes of a metal diaphragm; a vacuum degassing device is used to fully fill the specific upper and lower structural through-holes of the metal diaphragm with the uncured organic polymer material; the filled semi-pre-product is heat-treated to transform it into a semi-cured state; the semi-cured organic polymer material is then bonded to a cured organic polymer material of the same material; the cured organic polymer film layer and the semi-cured organic polymer film layer are subjected to hot-pressing treatment; the material after hot-pressing treatment undergoes a second curing process to achieve a fusion state of intermolecular bonding between the semi-cured organic polymer film layer and the upper cured organic polymer film layer.

9. The processing technology for an embedded metal-polymer flexible composite meshless screen printing plate for photovoltaic cell printing according to claim 8, characterized in that, Step three includes using a femtosecond laser for high-precision positioning and ablation to open windows in the upper and lower printing pastes.

10. The process for processing an embedded metal-polymer flexible composite meshless screen printing plate for photovoltaic cell printing according to claim 9, characterized in that, Step two includes using an electroforming process to create a nickel or nickel alloy metal intermediate film layer with a specific shape.

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