Photovoltaic glass screen printing process

Abstract

The invention discloses a photovoltaic glass screen printing process, which specifically comprises the following steps of S1, raw material preparation and pretreatment, S2, screen printing treatment, S3, sintering treatment and S4, post-treatment, and relates to the technical field of photovoltaic glass screen printing. According to the photovoltaic glass screen printing process, the width of a fine grid line is reduced to 28-31 [mu] m, the shading area is reduced, the photoelectric conversion efficiency of a photovoltaic module is improved, the reflectivity is greater than or equal to 83% and is improved by 5-8% compared with that of a traditional glaze through the application of high-reflectivity glaze, the utilization rate of light is remarkably improved, the power gain of the module reaches 0.3-0.5%, and the photovoltaic module has the advantages of being simple in structure, low in cost and high in practicability. By adding the modified acrylic resin and the silicon-coated titanium dioxide into the glaze, the anti-PID performance and the acid and alkali resistance (the alkali resistance reaches grade 1) are improved, the service life of a photovoltaic module is prolonged, and by optimizing a glaze application process, the viscosity stability and the printing quality are ensured, and printing defects such as plate pasting and uneven inking are reduced.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic glass screen printing technology, specifically a photovoltaic glass screen printing process. Background Technology

[0002] Currently, the screen printing process for photovoltaic module backsheet glass mainly uses 180-200 mesh screen fabric with a tension of 20±2N. While this process can complete basic printing tasks, it has the following problems: 1) A low mesh size results in a large printed fine grid line width (approximately 35-40μm), a large shading area, and affects the photoelectric conversion efficiency of the photovoltaic module; 2) High silver paste consumption increases production costs; 3) Traditional glazes have low reflectivity (approximately 75-80%), which fails to fully utilize light. 4) The glaze has insufficient weather resistance and is easily affected by environmental factors, leading to a shortened component lifespan; 5) The screen printing plate has a relatively short lifespan, usually around 10,000 to 20,000 uses, and frequent replacements increase production costs.

[0003] In existing technologies, although some companies have attempted to increase the mesh count, they often neglect innovation in the mesh structure. This leads to problems such as smudging and grid breakage in high-mesh-count screens during practical applications, preventing them from truly leveraging the advantages of high mesh count. Meanwhile, improvements in glaze formulations are mostly limited to enhancing single performance aspects, lacking a balance of comprehensive performance, making it difficult to meet the demands of high efficiency and long lifespan for photovoltaic modules. Summary of the Invention

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a photovoltaic glass screen printing process. Through innovation in mesh and fabric structure, improvement in glaze performance, and formula innovation, it achieves reduced shading area, lower silver paste consumption, increased reflectivity, enhanced weather resistance, extended screen life, and reduced production costs.

[0005] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a photovoltaic glass screen printing process, specifically comprising the following steps: S1. Raw material preparation and pretreatment: Glass substrate preparation, screen preparation and glaze preparation are carried out separately. S2. Silkscreen printing process, which includes the following steps: a1. Screen printing equipment debugging: Set the distance between the screen and the glass to 0.5-2mm, and select a polyurethane squeegee with a Shore hardness of 70-75. a2. Screen printing operation: Install the screen onto the printing press, ensuring it is parallel to the glass. Use a small amount of ink to add ink multiple times, controlling the amount added each time to 1 / 5 of the screen area. Move the squeegee from one end to the other at a uniform speed of 8-12m / min for screen printing. Apply 50-100N of pressure to the squeegee, with an angle of 20°-70° between the squeegee and the screen. Perform single or multiple printings according to design requirements. Perform preliminary drying immediately after screen printing to avoid ink leveling that could cause graphic deformation. a3. Step-by-step printing optimization; S3. Sintering Treatment: The printed glass is placed in a tempering furnace. The sintering temperature is controlled at 600-720℃, the sintering time is 40s / mm glass thickness, the heating rate is 10℃ / min, and the holding time is 3-5 minutes. After sintering, it is allowed to cool naturally to room temperature. During the sintering process, the glaze and the glass substrate are fully fused to form a uniform and stable high-reflectivity layer. After sintering, a glaze layer with a reflectivity of over 83% is formed on the glass surface, with an expansion coefficient of 82-87×10⁻⁶. -7 / ℃; S4. Post-processing: First, conduct quality inspection. Pack the qualified glass using anti-static packaging materials. Rework or scrap the unqualified glass. Record process parameters and quality data for subsequent process optimization.

[0006] Preferably, the glass substrate preparation in step S1 specifically involves: selecting photovoltaic backsheet glass with a thickness of 2-4mm, removing oil, oxides, and organic residues from the glass surface using an alkaline cleaning solution, followed by ultrasonic cleaning to enhance the cleaning effect, rinsing with ultrapure water after cleaning, and then treating the glass surface with low-temperature plasma bombardment to increase surface energy and form micro-roughness, thereby improving the adhesion of subsequent printing, and finally using infrared drying or nitrogen purging to thoroughly remove surface moisture, keeping the glass surface dry and avoiding secondary contamination.

[0007] Preferably, the screen preparation in step S1 specifically involves: selecting a knotless mesh fabric with a mesh count of 380 / 14 or 430 / 13, made of stainless steel or polyester; then using a diagonal stretching process to ensure uniform tension distribution in the warp and weft directions of the screen; controlling the screen tension within the range of 18-20N; using a tension meter to measure the tension at the four corners and the center point to ensure that the overall tension deviation is ≤1N / cm; controlling the thickness of the screen emulsion layer to 10-15μm; observing the sharpness of the graphic edges under a microscope; and ensuring the screen is clean and free of any residue to avoid smudging.

[0008] Preferably, the glaze preparation in step S1 is as follows: modified acrylic resin and silicone-coated titanium dioxide are selected as the main materials, and a special diluent is added according to the formula ratio of main material: diluent = 94:6. Then, the mixture is stirred for 3-5 hours using a high-speed mixer to ensure that the glaze is evenly dispersed. After stirring, the mixture is allowed to stand for 1-3 hours to defoam, ensuring a viscosity of 130±20 dPa·s (25℃). The glaze temperature is controlled at 20±2℃ to avoid affecting the viscosity due to temperature changes.

[0009] Preferably, step a3, the step-by-step printing optimization, specifically includes the following steps: T1. Main grid line printing: For the first printing of the main grid line, use a high solid content glaze with a solid content of ≥85%; T2, Fine grid line overlapping printing: After the first printing, the position of the fine grid lines is detected by a laser displacement sensor, and the screen is actively offset by 0.1-0.15mm during the second printing; T3. By using the paste superposition effect, the linewidth is reduced from 40μm to 30μm, increasing the light-receiving area by more than 3%; T4. Dynamic tension control of the screen: A pneumatic tensioning system is used to maintain the screen tension at 23-25 ​​N / cm. 2 It works in conjunction with piezoelectric ceramics to adjust local tension in real time.

[0010] Preferably, the quality inspection in step S4 is as follows: E1. Reflectance Test: Use a spectrometer to test the reflectance in the 380-1100nm spectral range, ensuring ≥83%; E2. Screen life test: Record the number of times the screen is used to ensure that it reaches more than 40,000 times; E3. Line width inspection: Use a microscope to inspect the width of fine grid lines to ensure it is 28-31μm; E4. Adhesion test: The adhesion of the glaze layer is tested using the cross-cut test to ensure that it reaches level 1. E5. Weather resistance test: Conduct a 1000-hour damp heat aging test to ensure that the reflectance decay rate is ≤3%.

[0011] Preferably, the environmental conditions in step a2 screen printing are specifically controlled as follows: screen printing room temperature 18-22℃, screen printing room humidity 50%-70%, environmental cleanliness ≥ ISO Class 5, and environmental parameters are monitored and recorded in real time to ensure process stability.

[0012] Preferably, in step a2, the optimal feeding time is calculated based on the printing speed, screen mesh count, and enamel characteristics. The specific calculation formula is as follows: Feeding time = (Printing speed × Screen area) / (Enamel flow rate × Screen mesh count); The specific interval for adding material is once every 5-10 minutes to ensure a sufficient supply of glaze without overflowing.

[0013] Preferably, in step S2, the process parameters are calibrated daily during the screen printing process to ensure consistency, the screen tension is tested weekly and adjusted in a timely manner, the glaze formula is tested monthly to ensure stable quality, and the entire process is systematically optimized quarterly to improve overall efficiency.

[0014] (III) Beneficial Effects This invention provides a screen printing process for photovoltaic glass. Compared with existing technologies, it has the following advantages: (1) The photovoltaic glass screen printing process reduces the fine grid line width to 28-31μm through high mesh count screen and no mesh knot screen technology, which reduces the shading area and improves the photoelectric conversion efficiency of photovoltaic modules. Through the application of high reflectivity glaze, the reflectivity is ≥83%, which is 5-8% higher than that of traditional glaze, significantly improving the light utilization rate and enabling the module power gain to reach 0.3-0.5%.

[0015] (2) The photovoltaic glass screen printing process improves the anti-PID performance and acid and alkali resistance (alkali resistance reaches level 1) by adding modified acrylic resin and silicon-coated titanium dioxide to the glaze, thus extending the service life of the photovoltaic module. Through the optimization of the glaze application process, the viscosity stability and printing quality are ensured, and printing defects such as smearing and uneven ink application are reduced.

[0016] (3) The photovoltaic glass screen printing process optimizes the sintering conditions, which makes the glaze layer and the glass substrate firmly bonded, improves the reliability and durability of the product, extends the screen life to more than 40,000 times, reduces the screen replacement frequency, and lowers the production cost.

[0017] (4) The photovoltaic glass screen printing process increases the module power gain by 0.3-0.5% while reducing the silver paste cost by 15-20%, achieving dual optimization of module power gain and silver paste cost, and maximizing the reduction of screen printing glass printing cost. Attached Figure Description

[0018] Figure 1 This is a flowchart of the photovoltaic glass screen printing process of the present invention. Detailed Implementation

[0019] 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.

[0020] Please see Figure 1 The present invention provides three technical solutions: a photovoltaic glass screen printing process, specifically including the following embodiments: Example 1: A photovoltaic glass screen printing process, specifically including the following steps: S1. Raw material preparation and pretreatment: Glass substrate preparation, screen preparation and glaze preparation are carried out separately. S2. Silkscreen printing process, which includes the following steps: a1. Screen printing equipment debugging: Set the distance between the screen and the glass to 1.2mm, and select a polyurethane squeegee with a Shore hardness of 73. a2. Screen printing operation: Install the screen onto the printing press, ensuring it is parallel to the glass. Use a small amount of ink to add ink multiple times, controlling the amount added each time to 1 / 5 of the screen area. Move the squeegee at a uniform speed of 10m / min from one end to the other for screen printing. Apply 70N pressure to the squeegee, with the squeegee and screen angle at 51°. Perform single or multiple printing according to design requirements. Perform preliminary drying immediately after screen printing to avoid ink leveling that could cause graphic deformation. a3. Step-by-step printing optimization; S3. Sintering Treatment: The printed glass is placed in a tempering furnace. The sintering temperature is controlled at 650℃, the sintering time is 40s / mm glass thickness, the heating rate is 10℃ / min, and the holding time is 4 minutes. After sintering, it is allowed to cool naturally to room temperature. During the sintering process, the glaze and the glass substrate are fully fused to form a uniform and stable high-reflectivity layer. After sintering, a glaze layer with a reflectivity of over 83% and an expansion coefficient of 85×10⁻⁶ is formed on the glass surface. -7 / ℃; S4. Post-processing: First, conduct quality inspection. Pack the qualified glass using anti-static packaging materials. Rework or scrap the unqualified glass. Record process parameters and quality data for subsequent process optimization.

[0021] In this embodiment of the invention, the preparation of the glass substrate in step S1 specifically involves: selecting photovoltaic backsheet glass with a thickness of 3mm, ensuring the surface cleanliness meets the ISO 10900 standard; removing oil, oxides, and organic residues from the glass surface using NaOH solution; then enhancing the cleaning effect with ultrasonic cleaning; rinsing with ultrapure water after cleaning; followed by low-temperature plasma bombardment treatment of the glass surface to increase surface energy and create micro-roughness, thereby improving the adhesion of subsequent printing; and finally, thoroughly removing surface moisture using infrared drying or nitrogen purging to keep the glass surface dry and avoid secondary contamination.

[0022] In this embodiment of the invention, the preparation of the screen printing plate in step S1 specifically involves: selecting a knotless screen fabric with a mesh count of 380 / 14 or 430 / 13, made of stainless steel or polyester; then using a diagonal stretching process to ensure uniform tension distribution in the warp and weft directions of the screen printing plate; controlling the screen printing plate tension within the range of 19N; using a tension meter to measure the tension at the four corners and the center point to ensure that the overall tension deviation is ≤1N / cm; controlling the thickness of the screen printing plate emulsion layer to 13μm; observing the sharpness of the graphic edges under a microscope; and ensuring the screen printing plate is clean and free of any residue to avoid smudging.

[0023] In this embodiment of the invention, the glaze preparation in step S1 is as follows: Modified acrylic resin and silicone-coated titanium dioxide are selected as the main materials, and then IP783 slow-drying water-specific diluent is added according to the formula ratio of main material: diluent = 94:6. Then, the mixture is stirred for 4 hours using a high-speed mixer to ensure that the glaze is evenly dispersed. After stirring, the mixture is allowed to stand for 2 hours to defoam, ensuring a viscosity of 130±20 dPa·s (25℃). The glaze temperature is controlled at 20℃ to avoid affecting the viscosity due to temperature changes.

[0024] In this embodiment of the invention, step a3, the step-by-step printing optimization, specifically includes the following steps: T1. Main grid line printing: For the first printing of the main grid line, use a high solid content glaze with a solid content of ≥85%; T2, Fine grid line overlapping printing: After the first printing, the position of the fine grid lines is detected by a laser displacement sensor, and the screen is actively offset by 0.13mm during the second printing; T3. By using the paste superposition effect, the linewidth is reduced from 40μm to 30μm, increasing the light-receiving area by more than 3%; T4. Dynamic tension control of the screen: A pneumatic tensioning system is used to maintain the screen tension at 24 N / cm. 2 It works in conjunction with piezoelectric ceramics to adjust local tension in real time.

[0025] In this embodiment of the invention, the quality inspection in step S4 is as follows: E1. Reflectance Test: Use a spectrometer to test the reflectance in the 880nm spectral range and ensure it is ≥83%; E2. Screen life test: Record the number of times the screen is used to ensure that it reaches more than 40,000 times; E3. Line width inspection: Use a microscope to inspect the width of fine grid lines to ensure 30μm; E4. Adhesion test: The adhesion of the glaze layer is tested using the cross-cut test to ensure that it reaches level 1. E5. Weather resistance test: Conduct a 1000-hour damp heat aging test to ensure that the reflectance decay rate is ≤3%.

[0026] In this embodiment of the invention, the environmental conditions in step a2 screen printing are specifically controlled as follows: screen printing room temperature 20℃, screen printing room humidity 60%, environmental cleanliness ≥ ISO Class 5. Environmental parameters are monitored and recorded in real time to ensure process stability. The optimal material feeding time is calculated based on printing speed, screen mesh count, and enamel characteristics. The specific calculation formula is as follows: Feeding time = (Printing speed × Screen area) / (Enamel flow rate × Screen mesh count); The specific interval for adding material is once every 8 minutes to ensure a sufficient supply of glaze without overflowing.

[0027] In this embodiment of the invention, during the screen printing process in step S2, the process parameters are calibrated daily to ensure consistency, the screen tension is tested weekly and adjusted in a timely manner, the glaze formula is tested monthly to ensure stable quality, and the entire process is systematically optimized quarterly to improve overall efficiency.

[0028] Example 2: A photovoltaic glass screen printing process, specifically including the following steps: S1. Raw material preparation and pretreatment: Glass substrate preparation, screen preparation and glaze preparation are carried out separately. S2. Silkscreen printing process, which includes the following steps: a1. Screen printing equipment debugging: Set the distance between the screen and the glass to 0.5mm, and select a polyurethane squeegee with a Shore hardness of 70. a2. Screen printing operation: Install the screen onto the printing press, ensuring it is parallel to the glass. Use a small amount of ink to add ink multiple times, controlling the amount added each time to 1 / 5 of the screen area. Move the squeegee at a uniform speed of 8m / min from one end to the other for screen printing. Apply 50N pressure to the squeegee, with the squeegee at a 20° angle to the screen. Perform single or multiple printings according to design requirements. Perform preliminary drying immediately after screen printing to avoid ink leveling that could cause graphic deformation. a3. Step-by-step printing optimization; S3. Sintering Treatment: The printed glass is placed in a tempering furnace. The sintering temperature is controlled at 600℃, the sintering time is 40s / mm glass thickness, the heating rate is 10℃ / min, and the holding time is 3 minutes. After sintering, it is allowed to cool naturally to room temperature. During the sintering process, the glaze and the glass substrate are fully fused to form a uniform and stable high-reflectivity layer. After sintering, a glaze layer with a reflectivity of over 83% and an expansion coefficient of 82×10⁻⁶ is formed on the glass surface. -7 / ℃; S4. Post-processing: First, conduct quality inspection. Pack the qualified glass using anti-static packaging materials. Rework or scrap the unqualified glass. Record process parameters and quality data for subsequent process optimization.

[0029] In this embodiment of the invention, the preparation of the glass substrate in step S1 specifically involves: selecting a photovoltaic backsheet glass with a thickness of 2mm, ensuring the surface cleanliness meets the ISO 10900 standard; removing oil, oxides, and organic residues from the glass surface using NaOH solution; then enhancing the cleaning effect with ultrasonic cleaning; rinsing with ultrapure water after cleaning; followed by low-temperature plasma bombardment treatment of the glass surface to increase surface energy and create micro-roughness, thereby improving the adhesion of subsequent printing; and finally, thoroughly removing surface moisture using infrared drying or nitrogen purging to keep the glass surface dry and avoid secondary contamination.

[0030] In this embodiment of the invention, the preparation of the screen in step S1 specifically involves: selecting a knotless screen fabric with a mesh count of 380 / 14 or 430 / 13, made of stainless steel or polyester; then using a diagonal stretching process to ensure uniform tension distribution in the warp and weft directions of the screen; controlling the screen tension within the range of 18N; using a tension meter to measure the tension at the four corners and the center point to ensure that the overall tension deviation is ≤1N / cm; controlling the thickness of the screen emulsion layer to 10μm; observing the sharpness of the graphic edges under a microscope; and ensuring the screen is clean and free of any residue to avoid smudging.

[0031] In this embodiment of the invention, the glaze preparation in step S1 is as follows: Modified acrylic resin and silicone-coated titanium dioxide are selected as the main materials, and then IP783 slow-drying water-specific diluent is added according to the formula ratio of main material: diluent = 94:6. Then, the mixture is stirred for 3 hours using a high-speed mixer to ensure that the glaze is evenly dispersed. After stirring, the mixture is allowed to stand for 1 hour to defoam, ensuring a viscosity of 130±20 dPa·s (25℃). The glaze temperature is controlled at 18℃ to avoid affecting the viscosity due to temperature changes.

[0032] In this embodiment of the invention, step a3, the step-by-step printing optimization, specifically includes the following steps: T1. Main grid line printing: For the first printing of the main grid line, use a high solid content glaze with a solid content of ≥85%; T2, Fine grid line overlapping printing: After the first printing, the position of the fine grid lines is detected by a laser displacement sensor, and the screen is actively offset by 0.1mm during the second printing; T3. By using the paste superposition effect, the linewidth is reduced from 40μm to 30μm, increasing the light-receiving area by more than 3%; T4. Dynamic tension control of the screen: A pneumatic tensioning system is used to maintain the screen tension at 23 N / cm. 2 It works in conjunction with piezoelectric ceramics to adjust local tension in real time.

[0033] In this embodiment of the invention, the quality inspection in step S4 is as follows: E1. Reflectance Test: Use a spectrometer to test the reflectance in the 380nm spectral range and ensure it is ≥83%; E2. Screen life test: Record the number of times the screen is used to ensure that it reaches more than 40,000 times; E3. Line width inspection: Use a microscope to inspect the width of fine grid lines to ensure 28μm; E4. Adhesion test: The adhesion of the glaze layer is tested using the cross-cut test to ensure that it reaches level 1. E5. Weather resistance test: Conduct a 1000-hour damp heat aging test to ensure that the reflectance decay rate is ≤3%.

[0034] In this embodiment of the invention, the environmental conditions in step a2 screen printing are specifically controlled as follows: screen printing room temperature 18℃, screen printing room humidity 50%, environmental cleanliness ≥ ISO Class 5. Environmental parameters are monitored and recorded in real time to ensure process stability. The optimal material feeding time is calculated based on printing speed, screen mesh count, and enamel characteristics. The specific calculation formula is as follows: Feeding time = (Printing speed × Screen area) / (Enamel flow rate × Screen mesh count); The glaze is added every 5 minutes to ensure a sufficient supply without overflowing.

[0035] In this embodiment of the invention, during the screen printing process in step S2, the process parameters are calibrated daily to ensure consistency, the screen tension is tested weekly and adjusted in a timely manner, the glaze formula is tested monthly to ensure stable quality, and the entire process is systematically optimized quarterly to improve overall efficiency.

[0036] Example 3: A photovoltaic glass screen printing process, specifically including the following steps: S1. Raw material preparation and pretreatment: Glass substrate preparation, screen preparation and glaze preparation are carried out separately. S2. Silkscreen printing process, which includes the following steps: a1. Screen printing equipment debugging: Set the distance between the screen and the glass to 2mm, and select a polyurethane squeegee with a Shore hardness of 75. a2. Screen printing operation: Install the screen onto the printing press, ensuring it is parallel to the glass. Use a small amount of ink to add ink multiple times, controlling the amount added each time to 1 / 5 of the screen area. Move the squeegee at a uniform speed of 12m / min from one end to the other for screen printing. Apply 100N of pressure to the squeegee, with the squeegee at a 70° angle to the screen. Perform single or multiple printings according to design requirements. Perform preliminary drying immediately after screen printing to avoid ink leveling that could cause graphic deformation. a3. Step-by-step printing optimization; S3. Sintering Treatment: The printed glass is placed in a tempering furnace. The sintering temperature is controlled at 720℃, the sintering time is 40s / mm glass thickness, the heating rate is 10℃ / min, and the holding time is 5 minutes. After sintering, it is allowed to cool naturally to room temperature. During the sintering process, the glaze and the glass substrate are fully fused to form a uniform and stable high-reflectivity layer. After sintering, a glaze layer with a reflectivity of over 83% and an expansion coefficient of 87×10⁻⁶ is formed on the glass surface. -7 / ℃; S4. Post-processing: First, conduct quality inspection. Pack the qualified glass using anti-static packaging materials. Rework or scrap the unqualified glass. Record process parameters and quality data for subsequent process optimization.

[0037] In this embodiment of the invention, the preparation of the glass substrate in step S1 specifically involves: selecting a photovoltaic backsheet glass with a thickness of 4mm, ensuring the surface cleanliness meets the ISO 10900 standard; removing oil, oxides, and organic residues from the glass surface using NaOH solution; then enhancing the cleaning effect with ultrasonic cleaning; rinsing with ultrapure water after cleaning; followed by low-temperature plasma bombardment treatment of the glass surface to increase surface energy and create micro-roughness, thereby improving the adhesion of subsequent printing; and finally, thoroughly removing surface moisture using infrared drying or nitrogen purging to keep the glass surface dry and avoid secondary contamination.

[0038] In this embodiment of the invention, the preparation of the screen printing plate in step S1 specifically involves: selecting a knotless screen fabric with a mesh count of 380 / 14 or 430 / 13, made of stainless steel or polyester; then using a diagonal stretching process to ensure uniform tension distribution in the warp and weft directions of the screen printing plate; controlling the screen printing plate tension within the range of 20N; using a tension meter to measure the tension at the four corners and the center point to ensure that the overall tension deviation is ≤1N / cm; controlling the thickness of the screen printing plate emulsion layer to 15μm; observing the sharpness of the graphic edges under a microscope; and ensuring that the screen printing plate is clean and free of any residue to avoid smudging.

[0039] In this embodiment of the invention, the glaze preparation in step S1 is as follows: Modified acrylic resin and silicone-coated titanium dioxide are selected as the main materials, and then IP783 slow-drying water-specific diluent is added according to the formula ratio of main material: diluent = 94:6. Then, the mixture is stirred for 5 hours using a high-speed mixer to ensure that the glaze is evenly dispersed. After stirring, the mixture is allowed to stand for 3 hours to defoam, ensuring a viscosity of 130±20 dPa·s (25℃). The glaze temperature is controlled at 22℃ to avoid affecting the viscosity due to temperature changes.

[0040] In this embodiment of the invention, step a3, the step-by-step printing optimization, specifically includes the following steps: T1. Main grid line printing: For the first printing of the main grid line, use a high solid content glaze with a solid content of ≥85%; T2, Fine grid line overlapping printing: After the first printing, the position of the fine grid lines is detected by a laser displacement sensor, and the screen is actively offset by 0.15mm during the second printing; T3. By using the paste superposition effect, the linewidth is reduced from 40μm to 30μm, increasing the light-receiving area by more than 3%; T4. Dynamic tension control of the screen: A pneumatic tensioning system is used to maintain the screen tension at 25 N / cm. 2 It works in conjunction with piezoelectric ceramics to adjust local tension in real time.

[0041] In this embodiment of the invention, the quality inspection in step S4 is as follows: E1. Reflectance Test: Use a spectrometer to test the reflectance in the 1100nm spectral range, ensuring it is ≥83%; E2. Screen life test: Record the number of times the screen is used to ensure that it reaches more than 40,000 times; E3. Line width inspection: Use a microscope to inspect the width of fine grid lines to ensure 31μm; E4. Adhesion test: The adhesion of the glaze layer is tested using the cross-cut test to ensure that it reaches level 1. E5. Weather resistance test: Conduct a 1000-hour damp heat aging test to ensure that the reflectance decay rate is ≤3%.

[0042] In this embodiment of the invention, the environmental conditions in step a2 screen printing are specifically controlled as follows: screen printing room temperature 22℃, screen printing room humidity 70%, environmental cleanliness ≥ ISO Class 5. Environmental parameters are monitored and recorded in real time to ensure process stability. The optimal material feeding time is calculated based on printing speed, screen mesh count, and enamel characteristics. The specific calculation formula is as follows: Feeding time = (Printing speed × Screen area) / (Enamel flow rate × Screen mesh count); The glaze is added every 10 minutes to ensure a sufficient supply without overflowing.

[0043] In this embodiment of the invention, during the screen printing process in step S2, the process parameters are calibrated daily to ensure consistency, the screen tension is tested weekly and adjusted in a timely manner, the glaze formula is tested monthly to ensure stable quality, and the entire process is systematically optimized quarterly to improve overall efficiency.

[0044] In summary, this invention reduces the fine grid linewidth to 28-31 μm through high-mesh-count and knotless screen printing technologies, thereby reducing the shading area and improving the photoelectric conversion efficiency of photovoltaic modules. The application of high-reflectivity glaze achieves a reflectivity ≥83%, 5-8% higher than traditional glazes, significantly improving light utilization and increasing module power gain by 0.3-0.5%. Furthermore, the addition of modified acrylic resin and silicon-coated titanium dioxide to the glaze enhances PID resistance and acid / alkali resistance (alkali resistance reaches level 1), extending the lifespan of the photovoltaic modules. By optimizing the glaze application process, viscosity stability and printing quality were ensured, reducing printing defects such as smearing and uneven ink application. Optimization of sintering conditions ensured a strong bond between the glaze layer and the glass substrate, improving product reliability and durability. The screen life was extended to over 40,000 cycles, reducing screen replacement frequency and production costs. Component power gain was increased by 0.3-0.5%, while silver paste costs were reduced by 15-20%, achieving dual optimization of component power gain and silver paste costs, maximizing the reduction of screen printing costs on glass.

[0045] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0046] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A photovoltaic glass screen printing process, characterized in that: Specifically, the following steps are included: S1. Raw material preparation and pretreatment: Glass substrate preparation, screen preparation and glaze preparation are carried out separately. S2. Silkscreen printing process, which includes the following steps: a1. Screen printing equipment debugging: Set the distance between the screen and the glass to 0.5-2mm, and select a polyurethane squeegee with a Shore hardness of 70-75. a2. Screen printing operation: Install the screen onto the printing press, ensuring it is parallel to the glass. Use a small amount of ink to add ink multiple times, controlling the amount added each time to 1 / 5 of the screen area. Move the squeegee from one end to the other at a uniform speed of 8-12m / min for screen printing. Apply 50-100N of pressure to the squeegee, with an angle of 20°-70° between the squeegee and the screen. Perform single or multiple printings according to design requirements. Perform preliminary drying immediately after screen printing to avoid ink leveling that could cause graphic deformation. a3. Step-by-step printing optimization; S3. Sintering Treatment: The printed glass is placed in a tempering furnace. The sintering temperature is controlled at 600-720℃, the sintering time is 40s / mm glass thickness, the heating rate is 10℃ / min, and the holding time is 3-5 minutes. After sintering, it is allowed to cool naturally to room temperature. During the sintering process, the glaze and the glass substrate are fully fused to form a uniform and stable high-reflectivity layer. After sintering, a glaze layer with a reflectivity of over 83% is formed on the glass surface, with an expansion coefficient of 82-87×10⁻⁶. -7 / ℃; S4. Post-processing: First, conduct quality inspection. Pack the qualified glass using anti-static packaging materials. Rework or scrap the unqualified glass. Record process parameters and quality data for subsequent process optimization.

2. The photovoltaic glass screen printing process according to claim 1, characterized in that: The glass substrate preparation in step S1 specifically involves: selecting photovoltaic backsheet glass with a thickness of 2-4mm; removing oil, oxides, and organic residues from the glass surface using an alkaline cleaning solution; enhancing the cleaning effect with ultrasonic cleaning; rinsing with ultrapure water after cleaning; then treating the glass surface with low-temperature plasma bombardment to increase surface energy and create micro-roughness, thereby improving the adhesion of subsequent printing; and finally thoroughly removing surface moisture using infrared drying or nitrogen purging to keep the glass surface dry and avoid secondary contamination.

3. The photovoltaic glass screen printing process according to claim 1, characterized in that: The screen preparation in step S1 specifically involves: selecting a knotless mesh fabric with a mesh count of 380 / 14 or 430 / 13, made of stainless steel or polyester; then using a diagonal stretching process to ensure uniform tension distribution in the warp and weft directions of the screen; controlling the screen tension within the range of 18-20N; using a tension meter to measure the tension at the four corners and the center point to ensure that the overall tension deviation is ≤1N / cm; controlling the thickness of the screen emulsion layer to 10-15μm; observing the sharpness of the graphic edges under a microscope; and ensuring the screen is thoroughly cleaned without any residue to avoid smudging.

4. The photovoltaic glass screen printing process according to claim 1, characterized in that: The specific steps for glaze preparation in step S1 are as follows: Modified acrylic resin and silicone-coated titanium dioxide are selected as the main materials, and a special diluent is added according to the formula ratio of main material: diluent = 94:

6. Then, a high-speed mixer is used to stir for 3-5 hours to ensure that the glaze is evenly dispersed. After stirring, the mixture is allowed to stand for 1-3 hours to defoam, ensuring a viscosity of 130±20 dPa·s. The glaze temperature is controlled at 20±2℃ to avoid affecting the viscosity due to temperature changes.

5. The photovoltaic glass screen printing process according to claim 1, characterized in that: The step a3 step-by-step printing optimization specifically includes the following steps: T1. Main grid line printing: For the first printing of the main grid line, use a high solid content glaze with a solid content of ≥85%; T2, Fine grid line overlapping printing: After the first printing, the position of the fine grid lines is detected by a laser displacement sensor, and the screen is actively offset by 0.1-0.15mm during the second printing; T3. By using the paste superposition effect, the linewidth is reduced from 40μm to 30μm, increasing the light-receiving area by more than 3%; T4. Dynamic tension control of the screen: A pneumatic tensioning system is used to maintain the screen tension at 23-25 ​​N / cm. 2 It works in conjunction with piezoelectric ceramics to adjust local tension in real time.

6. The photovoltaic glass screen printing process according to claim 1, characterized in that: The quality inspection in step S4 is as follows: E1. Reflectance Test: Use a spectrometer to test the reflectance in the 380-1100nm spectral range, ensuring ≥83%; E2. Screen life test: Record the number of times the screen is used to ensure that it reaches more than 40,000 times; E3. Line width inspection: Use a microscope to inspect the width of fine grid lines to ensure it is 28-31μm; E4. Adhesion test: The adhesion of the glaze layer is tested using the cross-cut test to ensure that it reaches level 1. E5. Weather resistance test: Conduct a 1000-hour damp heat aging test to ensure that the reflectance decay rate is ≤3%.

7. The photovoltaic glass screen printing process according to claim 1, characterized in that: In step a2, the environmental conditions for screen printing are specifically controlled as follows: screen printing room temperature 18-22℃, screen printing room humidity 50%-70%, environmental cleanliness ≥ ISO Class 5, and environmental parameters are monitored and recorded in real time to ensure process stability.

8. The photovoltaic glass screen printing process according to claim 1, characterized in that: In step a2, the optimal feeding time is calculated based on the printing speed, screen mesh count, and enamel characteristics. The specific calculation formula is as follows: Feeding time = (Printing speed × Screen area) / (Enamel flow rate × Screen mesh count); The specific interval for adding material is once every 5-10 minutes to ensure a sufficient supply of glaze without overflowing.

9. The photovoltaic glass screen printing process according to claim 1, characterized in that: In step S2, the screen printing process involves daily calibration of process parameters to ensure consistency, weekly tension testing of the screen and timely adjustments, monthly performance testing of the glaze formula to ensure stable quality, and quarterly system optimization of the entire process to improve overall efficiency.

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