Manufacturing method of metal alloy screen printing plate

Abstract

The invention relates to the technical field of printing screen manufacturing, and discloses a metal alloy screen manufacturing method which comprises the following steps: S1, etching a groove array on the front surface of a metal alloy substrate to obtain an ink storage structure layer; s2, the groove face of the ink storage structure layer is coated with an adhesive, and the adhesive is attached and pre-cured after being aligned with the metal alloy gauze; s3, aligning and calibrating the metal alloy gauze and the ink storage structure layer, and ablating the gauze by adopting ultraviolet laser to obtain a gauze pattern layer; s4, a through opening corresponding to the groove is machined in the back face of the metal alloy substrate, and a full-opening lower ink layer is obtained; and S5, final curing and post-treatment are conducted on the composite structure. The groove in the ink storage structure layer serves as a temporary storage and buffer space of the slurry, and the phenomenon of non-uniform supply caused by scraper movement can be reduced; by accurately controlling the etching depths of different pattern areas, the local slurry holding amount can be actively adjusted, and targeted slurry management is realized, so that the highly uniform ink layer thickness is obtained.

Description

Technical Field

[0001] This invention relates to the field of printing screen manufacturing technology, specifically a method for manufacturing a metal alloy screen. Background Technology

[0002] In precision graphic printing fields such as photovoltaic cell electrode printing, electronic circuit printing, and high-end glass decoration, metal alloy screens (usually made of stainless steel) are the core tools determining printing accuracy, uniformity, and efficiency. Their core function is to accurately deposit pastes (such as conductive silver paste, insulating paste, etc.) onto the substrate surface through precise graphic openings on the screen. Currently, mainstream metal alloy screens fall into two main technical categories, both of which have significant technical limitations: 1. Fully Opening Metal Stencil: This type of stencil is formed by laser cutting or chemical etching of a single thin metal sheet (usually 50-200μm thick) to create a completely open pattern. Its advantages are a direct and unobstructed ink path, high ink release efficiency, and sharp printed line edges. However, the main technical problems are as follows: Since its structural strength depends entirely on the metal frame of the unopened area, its graphic design is strictly limited to avoid collapse and deformation of large or complex graphic areas under printing pressure. To achieve complex patterns, it is often necessary to disassemble the graphic and perform multiple overprints, which not only increases the process steps and costs but also introduces cumulative alignment errors that are difficult to eliminate, severely restricting the freedom of product design and the performance of the final device.

[0003] 2. Composite Metal / Polymer Screens: To overcome the limitations of single materials, composite screens have emerged, in which polyester or stainless steel wire mesh is laid on a metal frame, and then partially or completely laminated with a polymer photosensitive film (such as latex) or a thin metal sheet. The image is formed on the film layer through exposure development or laser engraving. However, the main technical problems are as follows: First, the ink in the printing area must penetrate the polymer film layer and the warp and weft interlacing structure of the underlying mesh, resulting in high ink resistance, which easily leads to uneven ink transfer and jagged edges, making it difficult to obtain printed images with excellent aspect ratio and edge clarity. Second, the wear resistance, solvent resistance, and dimensional stability of polymer materials are generally weaker than those of metals, and the images are prone to wear, deformation, or film peeling during long-term printing and cleaning, affecting the printing life and consistency. Summary of the Invention

[0004] The purpose of this invention is to provide a method for manufacturing metal alloy screen printing plates to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for manufacturing a metal alloy screen includes the following steps: S1. Photoresist is coated on the front side of a metal alloy substrate. After exposure and development, an ink storage groove pattern window is formed. The groove array is etched out, and then the photoresist is removed to obtain the ink storage structure layer. S2. Apply adhesive to the grooved surface of the ink storage structure layer, align it with the metal alloy mesh using a CCD vision system, and then bond and pre-cure it. S3. Align and calibrate the composite metal alloy mesh with the ink storage structure layer below using another CCD vision system, and then use ultraviolet laser to ablate the mesh to form an opening for the printed pattern, thus obtaining the mesh pattern layer. S4. Using the groove in the ink storage structure layer as a reference, laser processing is used to create a through opening corresponding to the groove from the back of the metal alloy substrate to obtain a fully open ink layer. S5. Perform final curing and post-treatment on the composite structure.

[0006] As a further aspect of the present invention: in step S1, etching is performed using a ferric chloride etching solution with a concentration of 38–42 Bé, at 45–50°C by spraying, with the etching rate controlled at 12–15 μm / min.

[0007] As a further aspect of the present invention: in step S1, the depth of the etched groove is 30-70 μm, and the roughness Ra of the groove sidewall is not greater than 0.8 μm.

[0008] As a further embodiment of the present invention: in step S2, the bonding pre-curing is carried out in a vacuum bonding machine, with a bonding pressure of 0.4 to 0.6 MPa, a pre-curing temperature of 70 to 90°C, and a time of 3 to 5 minutes.

[0009] As a further aspect of the present invention: in step S2, the adhesive is epoxy resin or acrylic light-curing adhesive, and the thickness of the adhesive layer formed after the adhesive is pre-cured is 5 to 15 μm.

[0010] As a further aspect of the present invention: in step S3, the wavelength of the ultraviolet laser is 355nm, the power is 8-12W, the focal diameter is less than 20μm, and the positioning accuracy of the ablation path is less than ±8μm after compensation based on the CCD alignment system.

[0011] As a further embodiment of the present invention: in step S3, the mesh count of the mesh pattern layer is 250-500 mesh, the filament diameter is 18-35 μm, and the tension is 25-35 N / cm.

[0012] As a further aspect of the present invention: in step S4, the laser is a picosecond infrared laser; and the size of the processed through opening is larger than the bottom surface size of the groove, so as to form a release taper.

[0013] As a further aspect of the present invention: in step S5, the final curing temperature is 120-140°C, the curing time is 60-90 minutes, and the shear strength of the finally cured adhesive layer is not less than 15 MPa.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention imparts graphic forming capabilities to the upper high-tensile metal mesh layer and utilizes laser ablation technology to precisely process graphics of any complex shape. It breaks the constraint that traditional fully open steel mesh can only produce unidirectional non-connected lines, freeing product design from the limitations of screen printing technology and providing design space for device performance optimization.

[0015] The fully open metal ink layer ensures that the ink transfer path from the ink reservoir to the substrate is vertical, direct, and without any mesh obstruction. This results in thorough ink release with minimal resistance, producing printed lines with sharp edges, clear outlines, and high resolution. It effectively eliminates the jagged edge problem caused by mesh obstruction in traditional screen printing, significantly improving the geometric fidelity of the graphics.

[0016] The grooves in the ink storage structure layer serve as temporary storage and buffer spaces for the ink, which can reduce ink starvation or uneven supply caused by the movement of the doctor blade. By precisely controlling the etching depth of different pattern areas, the local ink holding amount can be actively adjusted to achieve targeted ink management, thereby obtaining a highly uniform ink layer thickness. Attached Figure Description

[0017] Figure 1 A schematic diagram of a method for manufacturing a metal alloy screen printing plate; Figure 2 This is a schematic diagram of the structure of a metal alloy screen in a method for manufacturing a metal alloy screen.

[0018] In the diagram: 1. Metal alloy substrate; 2. Mesh pattern layer; 3. Ink storage structure layer; 4. Fully open ink layer. Detailed Implementation

[0019] Please see Figure 1 and 2 In this embodiment of the invention, a method for manufacturing a metal alloy screen includes the following steps: S1. Photoresist is coated on the front side of the metal alloy substrate 1, and the ink storage groove pattern window is formed by exposure and development. For example, the metal alloy substrate 1 is a 316L stainless steel plate with a thickness of 100μm; the photoresist is a positive liquid photoresist with a thickness of 8-12μm, and is dried at 85-95℃; the exposure energy is 80-120 mJ / cm²; a 0.8-1.2% sodium carbonate solution is used to develop at 28-32℃ for 45-60 seconds to form the ink storage groove pattern window. Then, using a ferric chloride etching solution with a concentration of 38–42 Bé, etching is performed by spraying at 45–50°C, with the etching rate controlled at 12–15 μm / min; a groove array with a depth of 30–70 μm is etched, and the roughness Ra of the groove sidewall is not greater than 0.8 μm; then the photoresist is removed; for example, a special stripping solution is used to remove the remaining photoresist, and ultrasonic cleaning is performed with deionized water; thus, the ink storage structure layer 3 is obtained.

[0020] S2. Apply epoxy resin or acrylic UV-curable adhesive to the groove surface of the ink storage structure layer 3. After aligning it with the metal alloy mesh using a CCD vision system, perform pre-curing bonding in a vacuum laminating machine. The bonding pressure is 0.4–0.6 MPa, the pre-curing temperature is 70–90°C, and the time is 3–5 minutes. The thickness of the adhesive layer formed after pre-curing is 5–15 μm. For example, on the groove surface of the ink storage structure layer 3, a layer of epoxy resin with a viscosity of about 2500 cP is uniformly coated using a precision coating device, and the thickness of the adhesive layer is controlled to be 10 μm. Next, a 380-mesh stainless steel mesh (25μm wire diameter) with a tension of 30 N / cm is stretched flat on a temporary frame. Then, a CCD vision system is used to identify the etched groove outline on the ink storage structure layer 3 as a reference mark, and then the mesh is pre-cured in a vacuum laminator.

[0021] S3. The composite metal alloy mesh and the ink storage structure layer 3 below are aligned and calibrated using another CCD vision system. Then, an ultraviolet laser with a wavelength of 355nm, a power of 8-12W, and a focal diameter of less than 20μm is used to ablate the mesh. The positioning error of the ablation path of the ultraviolet laser is less than ±8μm, forming an opening for the printed pattern, thus obtaining the mesh pattern layer 2. The mesh pattern layer 2 has a mesh count of 250-500 mesh, a wire diameter of 18-35μm, and a tension of 25-35 N / cm.

[0022] S4. From the back of the metal alloy substrate 1, using the groove in the ink storage structure layer 3 as a reference, a through opening corresponding to the groove is processed by picosecond infrared laser to obtain a fully open ink layer 4; wherein, the size of the processed through opening is larger than the bottom surface size of the groove to form a release taper; for example, a picosecond infrared laser with an annular spot is used, with a power of 15-20W, a frequency of 200-300kHz, and a scanning speed of 1500-2500mm / s.

[0023] S5. Cur the composite structure at 120-140℃ for 60-90 minutes, and ensure that the shear strength of the adhesive layer after final curing is not less than 15MPa.

[0024] To better illustrate the technical effects of the present invention, the following experiments are conducted: A metal alloy composite mesh (CN210174380U) disclosed on the patent website was used as a comparative example; Example 1: A screen printing plate used for integrated printing of main and fine grids in heterojunction (HJT) solar cells.

[0025] Graphic design: Design an integrated graphic directly on the mesh graphic layer, including dense parallel fine grid lines and main grids with chamfered T-pads at the ends; all lines and pads are closed-loop graphics; Structural implementation: The etching depth of the ink storage structure layer corresponding to the fine gate and main gate lines is set to 45μm, and the depth of the T-type pad area is increased to 60μm to store more paste and ensure the fullness of the pad; Fabrication and parameters: Fabrication is carried out according to the steps S1-S5 above, wherein the mesh is 400 mesh (wire diameter 23μm), the stainless steel substrate is 100μm thick, the etching depth of the ink storage structure layer is controlled to 45±1.5μm in the fine gate area and 60±2μm in the pad area; the alignment accuracy of the dual CCD is calibrated to ±5μm; after laser ablation of the mesh, plasma is used to lightly etch the inner wall of the opening to further remove the adhesive residue.

[0026] Example 2: Screen printing plate for high-precision flexible circuit printing.

[0027] Graphic design: Design graphics containing closed loops and rounded square pads directly on the mesh graphic layer.

[0028] Structural implementation: The width of the groove in the ink storage structure layer is set to 110μm (10μm more than the target line width), and the depth is set to 35μm; when the lower ink layer is laser-cut, an annular spot is used in conjunction with a high-frequency galvanometer to achieve a micro-taper of 8μm on one side of the bottom.

[0029] Fabrication and parameters: The substrate is made of Invar alloy with a thickness of 80μm (low coefficient of expansion); the mesh is made of 500-mesh high-nickel alloy yarn (tension 32 N / cm); the adhesive is a low-shrinkage UV-thermal dual-curing adhesive; after laser ablation of the mesh, UV light is used for pre-curing and shaping, followed by back laser cutting and final thermal curing.

[0030] The screen printing plates prepared in Examples 1, 2 and the comparative examples were analyzed from the aspects of core structure, graphic carrier and design freedom, ink application mechanism and slurry management, functional structure, manufacturing process and precision control, and performance and effect, as shown in Table 1 below.

[0031] Table 1. Web Version Performance Analysis

[0032]

[0033] From Table 1 above, we can conclude that: 1. The comparative example aims to improve accuracy and lifespan by "supporting the polymer film with a metal sheet", but its pattern is still limited by the physical structure of the composite area, and the ink path is not truly fully open. The present invention fundamentally breaks out of this framework. By separating and precisely combining the pattern forming (mesh layer) with the slurry channel and support (fully open metal substrate), it solves the long-standing industry contradiction that arbitrary pattern design and efficient fully open ink application cannot be achieved at the same time.

[0034] 2. The unique ink storage groove layer and the fully open ink-dispensing layer on the all-metal substrate are technical features that are completely absent in this invention. These two features, combined with the high-tensile metal mesh pattern layer, produce a synergistic effect of "1+1+1>3": the ink storage structure layer optimizes the rheological behavior of the ink; the fully open ink-dispensing layer ensures complete ink release; and the mesh pattern layer provides unlimited graphic design capabilities. The three work together to achieve a comprehensive improvement in graphic design freedom, printing process controllability, and final printing quality.

[0035] 3. As can be seen from the embodiments, the present invention can achieve printing tasks that are fundamentally impossible to achieve with a proportional structure (such as printing an integrated pattern of main and fine grids with complex closed pads in one go), and raises key performance indicators (such as printing life, line edge accuracy, and alignment accuracy) to a new level.

[0036] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for manufacturing a metal alloy screen, characterized in that, Includes the following steps: S1. Photoresist is coated on the front side of a metal alloy substrate. After exposure and development, an ink storage groove pattern window is formed. The groove array is etched out, and then the photoresist is removed to obtain the ink storage structure layer. S2. Apply adhesive to the grooved surface of the ink storage structure layer, align it with the metal alloy mesh using a CCD vision system, and then bond and pre-cure it. S3. Align and calibrate the composite metal alloy mesh with the ink storage structure layer below using another CCD vision system, and then use ultraviolet laser to ablate the mesh to form an opening for the printed pattern, thus obtaining the mesh pattern layer. S4. Using the groove in the ink storage structure layer as a reference, laser processing is used to create a through opening corresponding to the groove from the back of the metal alloy substrate to obtain a fully open ink layer. S5. Perform final curing and post-treatment on the composite structure.

2. The method for manufacturing a metal alloy screen according to claim 1, characterized in that, In step S1, etching is performed using a ferric chloride etching solution with a concentration of 38–42 Bé, at 45–50°C by spraying, with the etching rate controlled at 12–15 μm / min.

3. The method for manufacturing a metal alloy screen according to claim 1, characterized in that, In step S1, the depth of the etched groove is 30-70 μm, and the roughness Ra of the groove sidewall is no greater than 0.8 μm.

4. The method for manufacturing a metal alloy screen according to claim 1, characterized in that, In step S2, the bonding pre-curing is carried out in a vacuum bonding machine with a bonding pressure of 0.4 to 0.6 MPa, a pre-curing temperature of 70 to 90°C, and a time of 3 to 5 minutes.

5. The method for manufacturing a metal alloy screen according to claim 1, characterized in that, In step S2, the adhesive is epoxy resin or acrylic light-curing adhesive, and the thickness of the adhesive layer formed after the adhesive is pre-cured is 5 to 15 μm.

6. The method for manufacturing a metal alloy screen according to claim 1, characterized in that, In step S3, the wavelength of the ultraviolet laser is 355nm, the power is 8-12W, the focal diameter is less than 20μm, and the positioning accuracy of the ablation path is less than ±8μm after compensation based on the CCD alignment system.

7. The method for manufacturing a metal alloy screen according to claim 1, characterized in that, In step S3, the mesh count of the mesh pattern layer is 250–500 mesh, the filament diameter is 18–35 μm, and the tension is 25–35 N / cm.

8. The method for manufacturing a metal alloy screen according to claim 1, characterized in that, In step S4, the laser is a picosecond infrared laser; and the size of the processed through opening is larger than the bottom surface size of the groove to form a release taper.

9. The method for manufacturing a metal alloy screen according to claim 1, characterized in that, In step S5, the final curing temperature is 120–140°C, the curing time is 60–90 minutes, and the shear strength of the finally cured adhesive layer is not less than 15 MPa.

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